Journal articles: 'Sulfuric material'

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Hyk, Wojciech, Konrad Kitka, and Dariusz Rudnicki. "Selective Recovery of Zinc from Metallurgical Waste Materials from Processing Zinc and Lead Ores." Molecules 24, no. 12 (June 19, 2019): 2275. http://dx.doi.org/10.3390/molecules24122275.

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A method for processing of metallurgical waste materials (chemically defined as sulfur-bearing zinc-ferric materials) produced by plants processing zinc ores and their concentrates is proposed. The method proposed is a combination of pyro- and hydrometallurgical treatments of the waste material. The crucial steps in the developed method include: roasting the material at 450 °C to generate sulfur dioxide (SO2), absorption of SO2 in an aqueous system to form sulfuric acid (IV), carbothermic decomposition of zinc ferrite compounds, and leaching of zinc from the roasted material using sulfuric (IV) acid. The method allows one to extract up to 40% of zinc from the waste material and, consequently, to generate a fraction of material with substantially higher content of iron oxides. The proposed method takes advantage of the presence of sulfur in the processed material which upon roasting is converted to sulfuric acid (IV)—a leaching agent for selective extraction of zinc. The properly adjusted pH of the aqueous medium in which the leaching process is carried out is the key factor determining the quantitative and selective separation of zinc. If the amount of sulfur in the processed material is insufficient, it may be supplemented by adding sulfuric acid (VI) to adjust the pH. The method proposed was tested at a laboratory scale and quarter industrial scale using the real samples taken from stockpiles in the vicinity of the plant processing zinc and lead ores in Poland. It may also work for any zinc-ferric materials from various sources.

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Amirabad, Morteza Mirzaei, Alireza Mirzaei Amirabad, Jafar Khodagholizadeh, and Ali Akbar Naeimi. "Producing Hydrogen through Electrolysis." Applied Mechanics and Materials 110-116 (October 2011): 2296–300. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.2296.

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In this paper, we discus about production Hydrogen for industrial and laboratories. We will discuss about methods of production Hydrogen and exquisite in electrolysis Power Acids. In this paper, compare some methods and materials. We prefer Sulfuric Acid. For electrolysis Sulfuric Acid, we need electrode. The material of electrode must refractory in corrosion by Sulfuric Acid. This material is alloy from palatine and other material. The physical face of electrode is too important and discus in this paper.

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Ivan, Eliansion, and Hindriyanto Dwi Purnomo. "FORECASTING PRICES OF FERTILIZER RAW MATERIALS USING LONG SHORT TERM MEMORY." Jurnal Teknik Informatika (Jutif) 3, no. 6 (December 26, 2022): 1663–73. http://dx.doi.org/10.20884/1.jutif.2022.3.6.433.

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This study uses long short term memory (LSTM) modeling to predict time series data on the price of fertilizer raw materials, namely prilled urea, granular urea, ammonium sulphate((NH4)2SO4), ammonia (NH3), diammonium phosphate((NH4)2HPO4 ), phosphoric acid (H3PO4), phosphate rock (P2O5), NPK 16-16-16, potash, sulfur, and sulfuric acid (H2SO4). Predictions are made based on data that existed in the past using the long short term memory method, which is a derivative of the recurrent neural network. Carry out the evaluation process by looking at the root mean square error (RMSE) and mean absolute percentage error (MAPE) of the model that has been created. The results obtained are quite good, as seen from the root mean square error (RMSE) and mean absolute percentage error (MAPE) which are close to 0 and not too high. Sulfur raw material got the smallest root mean square error (RMSE) with a score of 0.053 and diammonium phosphate raw material got the smallest mean absolute percentage error (MAPE) evaluation value with 2.3%, while the largest value was for the root mean square error (RMSE) of raw materials. Phosphoric acid fertilizer raw material with a value of 22,979 and the largest mean absolute percentage error (MAPE) comes from sulfuric acid fertilizer raw material with a value of 9.180%.

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Qiu, Chuan, Xian Zheng Gong, Wen Juan Chen, Zhi Hong Wang, Feng Gao, and Xiao Qing Li. "Materials Flows Analysis on the Beneficiation and Roasting Processes of a Typical Rare Earth Mineral." Materials Science Forum 847 (March 2016): 352–57. http://dx.doi.org/10.4028/www.scientific.net/msf.847.352.

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The aim of this paper is to explore material flow analysis, study the resource consumption and environmental impact of the production preparation process of typical rare earth materials. The results showed that in the beneficiation processes, producing one ton of rare earth concentrates (Rare Earth Oxide, REO50%) will also produces 27 tons of iron ore and 21 tons of tailings. The recovery of rare earths is only 16.8%. In roasting processes, roasting one ton (REO50%) of rare earth concentrates will emits 150 ~ 200Kg sulfuric acid mist, 500 ~ 600Kg sulfur dioxide, 30 ~ 40Kg fluoride, 30 ~ 50Kg smoke and1t (containing thorium) radioactive slag, and 1.2 tons of concentrated sulfuric acid should be used. The lower recoveries and large-scale of concentrated sulfuric acid used in roasting processes in rare earth industry are the main reasons lead to high pollution and high emissions.

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Reynosa-Martínez, Ana Cecilia, Erika Gómez-Chayres, Rafael Villaurrutia, and Eddie López-Honorato. "Controlled Reduction of Graphene Oxide Using Sulfuric Acid." Materials 14, no. 1 (December 25, 2020): 59. http://dx.doi.org/10.3390/ma14010059.

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Sulfuric acid under different concentrations and with the addition of SO3 (fuming sulfuric acid) was studied as a reducing agent for the production of reduced graphene oxide (RGO). Three concentrations of sulfuric acid (1.5, 5, and 12 M), as well as 12 M with 30% SO3, were used. The reduction of graphene oxide increased with H2SO4 concentration as observed by Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy. It was observed that GO lost primarily epoxide functional groups from 40.4 to 9.7% and obtaining 69.8% carbon when using 12 M H2SO4, without leaving sulfur doping. Additionally, the appearance of hexagonal domain structures observed in transmission electron microscopy and analyzed by selected area electron diffraction patterns confirmed the improvement in graphitization. Although the addition of SO3 in H2SO4 improved the GO reduction with 74% carbon, as measured by XPS, the use of SO3 introduced sulfur doping of 1.3%. RGO produced with sulfuric acid was compared with a sample obtained via ultraviolet (UV) irradiation, a very common reduction route, by observing that the RGO produced with sulfuric acid had a higher C/O ratio than the material reduced by UV irradiation. This work showed that sulfuric acid can be used as a single-step reducing agent for RGO without sulfur contamination.

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Trushkova, Ekaterina, Elena Omelchenko, and Mikhail Sidelnikov. "Improvement of environmental indicators of coal energy and agricultural production due to the integration and diversification of these industries." E3S Web of Conferences 217 (2020): 04008. http://dx.doi.org/10.1051/e3sconf/202021704008.

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At present, there is extensive experience in the use of sulfuric acid ameliorant for soils with soda type of salinity. The authors found that as a result of using a weak solution of sulfuric acid on soils containing sodium and hydrocarbonates in their salt composition, their agrochemical characteristics are significantly improved. The article presents the results that show that the production of fertilizers and ameliorants from the waste of energy enterprises will increase their environmental safety. The use of sulfur oxides captured from the flue gases of coal-fired energy enterprises as a raw material for the production of sulfuric ameliorant will allow solving a double task: to reduce pollution of the zone of influence of enterprises and improve the condition of lands with soda salinization.

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Li, Yong Li, Li Ping Mao, Cai Feng Xu, and Shi You Li. "A Preliminary Study of the Carbon-Based Solid Acid Preparation Process." Advanced Materials Research 734-737 (August 2013): 2236–39. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.2236.

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Cotton and sulfuric acid that concentration is 98% as the raw material, to compare the resulting solid carbon sulfonic acid content of the material under different reaction temperatures. FTIR analysis shows that the cotton carbon is an amorphous carbon after sulfonation reactions, a sulfonic acid group present in the resulting material. When the sulfonation temperature is 170 °C, the prepared cotton carbon sulfonic acid has the highest acid content. By the sulfuric acid TG/DTG curve analysis, it verify: 170 °C is the highest activity temperature point of sulfuric acid sulfonation reaction.

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Sultana, Sujala T., and M. Ruhul Amin. "Aspen-Hysys Simulation Of Sulfuric Acid Plant." Journal of Chemical Engineering 26 (March 24, 2012): 47–49. http://dx.doi.org/10.3329/jce.v26i1.10182.

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This work presents a theoretical investigation of the simulation of Sulfuric acid process plant. In the production of the acid in contact process liquid sulfur is sequentially oxidized to Sulfur tri oxide via an exothermic reaction which is absorbed by 98% Sulfuric acid in an absorption tower. In this research Aspen One V7.2 has been successfully used to design every sub-process of the sulfuric acid plant in one integrated environment. In order to simulate the process as accurately as possible COM thermo was selected as advanced thermodynamics. Electrolyte NRTL and Peng-Robinson were used for liquid and vapor phase respectively as fluid package and HYSYS properties were used for simulation. The simulation of sulfuric acid process included automatic chemistry generation and the capacity of handling electrolyte reactions for all unit models. Aspen-HYSYS provides specialized thermodynamics models and built-in data to represent the non-ideal behavior of liquid phase components in order to get accurate results. Material and energy flows, sized unit operations blocks can be used to conduct economic assessment of each process and optimize each of them for profit maximization. The simulation model developed can also be used as a guide for understanding the process and the economics, and also a starting point for more sophisticated models for plant designing and process equipment specifying. DOI: http://dx.doi.org/10.3329/jce.v26i1.10182 JCE 2011; 26(1): 47-49

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9

Álvarez, María Luisa, José Manuel Fidalgo, Gabriel Gascó, and Ana Méndez. "Hydrometallurgical Recovery of Cu and Zn from a Complex Sulfide Mineral by Fe3+/H2SO4 Leaching in the Presence of Carbon-Based Materials." Metals 11, no. 2 (February 6, 2021): 286. http://dx.doi.org/10.3390/met11020286.

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Chalcopyrite, the main ore of copper, is refractory in sulfuric media with slow dissolution. The most commonly employed hydrometallurgical process for the oxidation of chalcopyrite and copper extraction is the sulfuric acid ferric sulfate system The main objective of the present work is to study the use of cheap carbon-based materials in the leaching of copper and zinc from a sulfide complex mineral from Iberian Pyrite Belt (IPB). The addition effect of commercial charcoal (VC) and two magnetic biochars (BM and HM) that were obtained by pyrolysis of biomass wastes was compared to that of commercial activated carbon (AC). The experimental results performed in this work have shown that the presence of carbon-based materials significantly influences the kinetics of chalcopyrite leaching in the sulfuric acid ferric sulfate media at 90 °C. The amount of copper and zinc extracted from IPB without the addition of carbon-based material was 63 and 72%, respectively. The highest amount of extracted zinc (>90%) was obtained with the addition of VC and AC in IPB/carbon-based material ratio of 1/0.25 w/w. Moreover, it is possible to recover more than 80% of copper with the addition of VC in a ratio 1/0.25 w/w. Moreover, an optimization of the properties of the carbon-based material for its potential application as catalyst in the leaching of metals from sulfide is necessary.

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Nisah, Khairun. "EKSTRAKSI ALUMINA OKSIDA ( Al2O3) DARI TANAH LIAT DENGAN VARIABEL SUHU DAN KONSENTRASI ASAM SULFAT." Lantanida Journal 4, no. 1 (September 15, 2017): 1. http://dx.doi.org/10.22373/lj.v4i1.1833.

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In this study used clay as raw material for making aluminum oxide using sulfuric acid as pelarut.Penelitian also aims to obtain sulfuric acid concentration and reaction time is best, where the variable used is the concentration of sulfuric acid ( 60 % , 70 % and 80 % ) and reaction time ( 40 minutes , 50 minutes and 60 minutes). The results showed that the greater the concentration of sulfuric acid , the levels of aluminum oxide obtained will be greater and greater the heating period , the levels of aluminum oxide obtained will also be greater . Optimum results obtained in 80% sulfuric acid concentration and reaction time 60 minutes.

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M. Salman, Mohammed, Qais J. Frayyeh, and Luma A. Zghair. "STRESS –STRAIN DIAGRAM OF SELF-CONSOLIDATING CONCRETE SUBJECTED TO CHEMICAL ATTACK." Journal of Engineering and Sustainable Development 26, no. 5 (September 1, 2022): 105–14. http://dx.doi.org/10.31272/jeasd.26.5.10.

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Self-consolidating concrete (SCC) is increasingly used in a number of concrete applications, some of which are highly susceptible to attack by sulfuric acid. This work aimed to study the resistance of a wide range of different SCCs to sulfuric attack. The main variables studied included binder material type (highly reactive materials), limestone powder, and hybrid fibers in this work, compaction, L-box, and V-hopper were performed for the new mixtures. In this study, the specimens were immersed in a solution of sulfuric acid at a concentration (0.5%) for up to 289 days after normal curing for 28 days. Laboratory results show that concrete containing pozzolanic material has reduced mechanical properties compared to a mixture containing only limestone powder. The study also showed that there was an improvement in the resistance of concrete to acid solutions when hybrid fibers were added to the concrete mix. From the stress graph, the strain at given axial stress will be less than once the failure becomes more severe, it will become less rigid than immersing the specimen for six months.

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Terrones-Saeta, Juan María, Jorge Suárez-Macías, Evaristo Rafael Moreno-López, and Francisco Antonio Corpas-Iglesias. "Leaching of Zinc for Subsequent Recovery by Hydrometallurgical Techniques from Electric Arc Furnace Dusts and Utilisation of the Leaching Process Residues for Ceramic Materials for Construction Purposes." Metals 11, no. 10 (October 9, 2021): 1603. http://dx.doi.org/10.3390/met11101603.

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Steel is one of the most widely used materials in the past and today. Various techniques are used to recycle this material, including the electric arc furnace. This process has several advantages, but it also has a major disadvantage, namely, the generation of waste such as electric arc furnace dusts. Electric arc furnace dusts are classified as hazardous waste due to their high percentage of heavy metals, including zinc. Consequently, in the present research, the leaching of zinc for recovery with sulfuric acid solutions at ambient temperature and atmospheric pressure is evaluated, as well as the reuse of the leaching process residue as a raw material for ceramic materials. The sulfuric acid solutions were 0.125, 0.25, 0.5, and 1 molar, using clay for ceramic conforming and percentages of the leaching residue from 0–50%. The results showed that the optimum solution was 1 molar sulfuric acid, recovering all the zinc in the sample in 36 h. Furthermore, it was found that the clay-conformed ceramics with less than 40% leaching residue showed acceptable physical and mechanical properties according to standards. Therefore, this research develops a new environmental hydrometallurgy in which metallic elements of interest are valorized and the production of waste is avoided, reducing the deposition of hazardous waste in landfills and the extraction of raw materials for the manufacture of construction materials.

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13

Rajkovic, Milos. "Accidents with sulfuric acid." Chemical Industry 60, no. 9-10 (2006): 221–38. http://dx.doi.org/10.2298/hemind0610221r.

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Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006) are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents) in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old) tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc). The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

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Liu, Jun Ping, Huan Zhen Zhang, and Xiao Meng Liu. "Commercial Activated Carbon Modified with Sulfuric Acid: A Potential Permeable Reactive Barrier Material for In Situ Remediation of Cr(VI) from Groundwater." Advanced Materials Research 343-344 (September 2011): 172–76. http://dx.doi.org/10.4028/www.scientific.net/amr.343-344.172.

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In this study, removal of Cr(Ⅵ) from synthetic groundwater by adsorption onto commercial activated carbon (CAC) made up of coconut shell is investigated in batch studies. Surface modification of CAC with sulfuric acid is also conducted to evaluate its removal performance. It is evident that CAC chemically modified with sulfuric acid (sulfuric-treated CAC) demonstrates higher Cr(Ⅵ) removal efficiency than non-treated CAC in dealing with contaminated groundwater with the pH is about 7.0, suggesting that sulfuric-treated CAC is suitable for the in-situ remediation of Cr(Ⅵ) contaminated groundwater. Adsorption of Cr(Ⅵ) is strongly affected by pH, the granular sulfuric-treated CAC exhibits the highest Cr(Ⅵ) adsorption capacity at pH 1.5 and the maximum Cr(Ⅵ) adsorption capacity of which estimated with the Langmuir model was 8.24mg/g.

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Jabłoński, Maciej, Krzysztof Lubkowski, Sandra Tylutka, and Andrzej Ściążko. "Heat effects in the reaction of sulfuric acid with ilmenites influenced by initial temperature and acid concentration." Polish Journal of Chemical Technology 23, no. 3 (September 1, 2021): 37–42. http://dx.doi.org/10.2478/pjct-2021-0028.

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Abstract The influence of temperature and sulfuric acid concentration on the enthalpy and the rate of heat release during the reaction of Norwegian and Australian ilmenites with sulfuric acid was determined. The experimental results obtained from calorimetric measurements were compared with theoretical calculations based on the oxide composition and the phase composition of the raw material. Experimentally determined heat of reaction for Norwegian ilmenite (900–940 kJ/kg) and Australian ilmenite (800–840 kJ/kg) showed good agreement with theoretical calculations based on the phase composition of the raw material. It was found that the enthalpy of ilmenites decomposition reaction does not depend on the concentration of sulfuric acid in the concentration range from 83% to 93%. It was also demonstrated that the temperature and concentration of sulfuric acid have a significant impact on the thermokinetics of the decomposition process, increasing the value of the average rate of temperature change.

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Sotoku, Kota, Masaki Inaba, and Hiroaki Takahashi. "Organic Material Removal by Thermally Activated Ozone Gas." Solid State Phenomena 282 (August 2018): 19–24. http://dx.doi.org/10.4028/www.scientific.net/ssp.282.19.

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We investigated an alternative technology to conventional organic material removal that replaces sulfuric acid and hydrogen peroxide (SPM). We assumed that the removal model of organic material by ozone gas was absorption of oxygen radicals, generated by thermal decomposition of ozone, on a surface and subsequent reaction with organic materials. Then we characterized the correlation between removal rate and process parameter, and the validity of the model was verified. It also showed that this method is effective for high dose, ion-implanted photoresists.

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Kusbiantoro, Andri, Amalina Hanani, and Rahimah Embong. "Pozzolanic Reactivity of Coal Bottom Ash after Chemically Pre-Treated with Sulfuric Acid." Materials Science Forum 947 (March 2019): 212–16. http://dx.doi.org/10.4028/www.scientific.net/msf.947.212.

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Current trend in construction industry has highlighted the use of silica-rich supplementary cementitious materials from industrial wastes in the production of concrete. Numerous studies have validated the pozzolanic properties of these materials, yet coal bottom ash received only infamous reputation as a pozzolanic material, owing to its low reactivity and heavy metals contaminants. Therefore this study was purposed to enhance the pozzolanic reactivity of coal bottom ash through chemical pre-treatment process. Different concentrations of acids and treatment period were studied to obtain optimum parameters for pre-treatment process. Treated ash was characterized for its chemical oxide composition. Its effect on the hydration of cement was studied through the inclusion as cement replacement material in mortar mixtures. From the chemical oxide compositions, a combination of 0.5 M of H2SO4 and 1 hour soaking duration presented the highest SiO2 proportion in the ash. Its inclusion at 5% (by weight of cement) to replace cement proportion in mortar mixtures was able to enhance the compressive strength of mortar at later age, regardless of its slower strength development in the early age. Utilizing treated coal bottom ash as partial cement replacement material has unlocked new achievement for greener future in construction industry.

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Ma, Jiqiang, Junying Hao, Qinling Bi, LiCai Fu, Jun Yang, and Weimin Liu. "Tribological properties of a Fe3Al material in sulfuric acid corrosive environment." Wear 268, no. 1-2 (January 2010): 264–68. http://dx.doi.org/10.1016/j.wear.2009.07.018.

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El Hazek, Mona N., and Azza A. Gabr. "Dissolution of Manganese from Polymetallic Material Using Sulfuric-Oxalic Acid Medium." American Journal of Analytical Chemistry 07, no. 05 (2016): 469–77. http://dx.doi.org/10.4236/ajac.2016.75044.

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Grzesiak, Piotr, Marcin Grobela, and Rafał Motała. "The influence of the catalyst worktime on SO2 emission quantity from the sulfuric acid system and the catalyst waste material." Polish Journal of Chemical Technology 9, no. 3 (January 1, 2007): 134–37. http://dx.doi.org/10.2478/v10026-007-0073-0.

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The influence of the catalyst worktime on SO2 emission quantity from the sulfuric acid system and the catalyst waste material The catalytic process of SO2 to SO3 oxidation is the main step of sulfuric (VI) acid formation. The sustained catalyst operating due to its structural and textural modifications could disturb the process course. This paper includes the influence of the vanadic catalyst worktime on SO2 emission and the expected amount of the obtained waste material of the inactivated catalyst.

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Zhao, He Fei, Shu Ming Wen, Shao Jun Bai, Ci Yun Chen, and Qi Cheng Feng. "Experimental Study on Removal of Arsenic from Sulfuric-Acid Residue of High-Arsenic." Advanced Materials Research 634-638 (January 2013): 3363–67. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.3363.

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The experimental study on removal of arsenic from sulfuric-acid residue of high-arsenic was conducted in this paper. Reduction roasting–magnetic separation and sulfuric acid leaching were discussed, and the results showed that the harmful impurity arsenic can't be effectively removed by the reduction roasting-magnetic separation process from sulfuric-acid residue. The content of arsenic would be enriched with the growth of magnetic iron grade, while the effect of the arsenic removal was obvious for sulfuric acid leaching. The leach residue, in which the content of arsenic was only 0.24% with 92.29% of arsenic leaching rate was obtained from the raw ore with 2.78% of arsenic by the sulfuric acid leaching process. And the iron grade of sulfuric-acid residue reached 61.88% while content of non-ferrous metal was very Low, which can be used as a raw material of iron-smelting. This study provided a certain amount of technical support for the similar high arsenic sulfuric-acid residue recycling.

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Fan, Wei, Yan Zhuge, Xing Ma, Christopher W. K. Chow, Nima Gorjian, Jeong-A. Oh, and Weiwei Duan. "Durability of Fibre-Reinforced Calcium Aluminate Cement (CAC)–Ground Granulated Blast Furnace Slag (GGBFS) Blended Mortar after Sulfuric Acid Attack." Materials 13, no. 17 (August 29, 2020): 3822. http://dx.doi.org/10.3390/ma13173822.

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Concrete wastewater infrastructures are important to modern society but are susceptible to sulfuric acid attack when exposed to an aggressive environment. Fibre-reinforced mortar has been adopted as a promising coating and lining material for degraded reinforced concrete structures due to its unique crack control and excellent anti-corrosion ability. This paper aims to evaluate the performance of polyethylene (PE) fibre-reinforced calcium aluminate cement (CAC)–ground granulated blast furnace slag (GGBFS) blended strain-hardening mortar after sulfuric acid immersion, which represented the aggressive sewer environment. Specimens were exposed to 3% sulfuric acid solution for up to 112 days. Visual, physical and mechanical performance such as water absorption ability, sorptivity, compressive and direct tensile strength were evaluated before and after sulfuric acid attack. In addition, micro-structure changes to the samples after sulfuric acid attack were also assessed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to further understand the deterioration mechanism. The results show that overall fibre-reinforced calcium aluminate cement (CAC)-based samples performed significantly better than fibre-reinforced ordinary Portland cement (OPC)-based samples as well as mortar samples in sulfuric acid solution in regard to visual observations, penetration depth, direct tensile strength and compressive reduction. Gypsum generation in the cementitious matrix of both CAC and OPC-based systems was the main reason behind the deterioration mechanism after acid attack exposure. Moreover, laboratory sulfuric acid testing has been proven for successfully screening the cementitious material against an acidic environment. This method can be considered to design the service life of concrete wastewater pipes.

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MATSUOKA, Satoru, Hiroyuki SAKAKIBARA, Yasuko MOCHIDA, and Makoto KAWAKAMI. "STUDY ON JOINT SEALING MATERIAL AND REPAIRING MATERIAL APPLIED FOR SULFURIC ACID RESISTANT PRECAST CONCRETE PRODUCTS." Cement Science and Concrete Technology 64, no. 1 (2010): 509–14. http://dx.doi.org/10.14250/cement.64.509.

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Zheng, Dingyuan, Yangyang Zhang, Yunfeng Guo, and Jinquan Yue. "Isolation and Characterization of Nanocellulose with a Novel Shape from Walnut (Juglans Regia L.) Shell Agricultural Waste." Polymers 11, no. 7 (July 3, 2019): 1130. http://dx.doi.org/10.3390/polym11071130.

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Herein, walnut shell (WS) was utilized as the raw material for the production of purified cellulose. The production technique involves multiple treatments, including alkaline treatment and bleaching. Furthermore, two nanocellulose materials were derived from WS by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation and sulfuric acid hydrolysis, demonstrating the broad applicability and value of walnuts. The micromorphologies, crystalline structures, chemical functional groups, and thermal stabilities of the nanocellulose obtained via TEMPO oxidation and sulfuric acid hydrolysis (TNC and SNC, respectively) were comprehensively characterized. The TNC exhibited an irregular block structure, whereas the SNC was rectangular in shape, with a length of 55–82 nm and a width of 49–81 nm. These observations are expected to provide insight into the potential of utilizing WSs as the raw material for preparing nanocellulose, which could address the problems of the low-valued utilization of walnuts and pollution because of unused WSs.

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Yang, Shuhua, Qian Guan, Zijie Li, Haiyan Xu, Zhiwei Wang, Gaofeng Chen, Lu Lin, and Tingzhou Lei. "Study on the Influence of Different Catalysts on the Preparation of Ethyl Levulinate from Biomass Liquefaction." Journal of Biobased Materials and Bioenergy 14, no. 3 (June 1, 2020): 396–400. http://dx.doi.org/10.1166/jbmb.2020.1979.

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The liquefaction experiments of straw biomass under heating and pressure were carried out with sulfuric acid and three ionic liquids as catalysts, 1-Butyl-3-methylimidazolium chloride ([BMIM] [Cl]), 1-Butyl-3-methylimidazolium hydrogen sulfate ([BMIM] [HSO4]), 1-methyl-3-(4-sulfobutyl) imidazole bisulphate ([HSO3-BMIM] [HSO4]), and anhydrous ethanol as solvent. The effects of catalyst type and dosage, reaction time and reaction temperature on liquefaction were investigated and optimized. The results showed that under the catalysis of sulfuric acid, the yield of ethyl levulinate was the highest; [HSO3-BMIM] [HSO4], the conversion of raw materials was the highest; when sulfuric acid was used as catalyst, the optimum reaction conditions were catalyst dosage 10%, reaction temperature 190 °C, reaction time 60 min, the yield of ethyl levulinate (EL) was 18.11%, and the conversion of raw materials was 75%. When [HSO3-BMIM] [HSO4] was used as catalyst, the optimum reaction conditions were as follows: catalyst dosage 26%, reaction temperature 200 °C, reaction time 60 min, the yield of EL was 10.2%, conversion of raw material 85.31%.

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Cabral-Miramontes, José, Facundo Almeraya-Calderón, Francisco Estupinán López, María Lara Banda, Javier Olguín-Coca, Luis Daimir López-León, Ivan Castañeda-Robles, Miguel Ángel Esneider Alcalá, Patricia Zambrano-Robledo, and Citlalli Gaona-Tiburcio. "Citric Acid as an Alternative to Sulfuric Acid for the Hard-Anodizing of AA6061." Metals 11, no. 11 (November 16, 2021): 1838. http://dx.doi.org/10.3390/met11111838.

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Hard-anodized is a widely used method in the aeronautical sector to improve aluminum alloys abrasion and corrosion resistance. Aim of this work was to characterize the mechanical properties and resistance hard-anodized aluminum 6061 in citric acid solution as a replacement sulfuric acid solution were investigated. Aluminum alloy 6061 was used as the base material to produce the hard anodizing; this process was carried out in a citric and sulfuric acid solution, applying current densities 3 and 4.5 A/cm2 and subsequently exposed to 3.5 wt. % NaCl solution. Microstructure and mechanical properties of the anodizing material were characterized by scanning electron microscopy (SEM) and Vickers microhardness (HV). Corrosion behavior of the hard-anodized material it was carried out with electrochemical techniques as cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS) respectively. Results obtained indicated that all samples anodized in citric acid solution showed negative hysteresis and lower corrosion current density (1 × 10−10 A/cm2), indicating generalized corrosion on the material surface. EIS results show that anodizing in citric acid solution and a current density of 4.5 A/dm2 provides better corrosion protection than a sulfuric acid solution.

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Sulistiyono, Eko, Murni Handayani, Agus Budi Prasetyo, Januar Irawan, Eni Febriana, Florentinus Firdiyono, Erlina Yustanti, Safetyana Nazaretha Sembiring, Firdaus Nugroho, and Ersan Yudhapratama Muslih. "Implementation of sulfuric acid leaching for aluminum and iron removal for improvement of low-grade silica from quartz sand of Sukabumi, Indonesia." Eastern-European Journal of Enterprise Technologies 3, no. 6 (111) (June 18, 2021): 32–40. http://dx.doi.org/10.15587/1729-4061.2021.226267.

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Indonesia has very abundant reserves of silica, but progressive studies on the deposition of this material are very few, resulting in limited applications of silica. This work refers to the purification of silica from quartz sand originated from Sukabumi, Indonesia to obtain high-purity silica, which can be applied as important raw materials for special purposes. The aim of our research is to improve low-grade silica from quartz sand by removing impurities, especially aluminum and iron removal, using sulfuric acid leaching. In order to achieve the aim, the effect of reaction time and sulfuric acid concentration on the leaching process was investigated. The effectiveness of sulfuric acid for the impurities removal was observed. The chemical composition of the samples before and after leaching was studied using X-ray fluorescence. The mineralogical analysis of the starting materials and the products was conducted using X-ray diffraction. Microstructure analysis was performed using a scanning electron microscope, and EDS test was used to show the element composition at different points. The experimental results show that the optimum condition of the leaching process occurs at a reaction time of 5 hours with a sulfuric acid concentration of 10 N. The silica levels increase from 93.702 % to 96.438 %. Aluminum and iron impurities reduced from 4.691 % to 2.712 % and from 0.641 % to 0.094 %, respectively. At this optimum point, sulfuric acid is very effective to remove aluminum and iron impurities up to 42 % and 85 %, respectively. The results of this research can be a very significant opportunity to increase the value added of quartz sand from Sukabumi, which can enhance the quality of low-grade silica to provide better raw materials for glass industries.

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Zulhan, Zulfiadi, Zhahrina Adzana, Mona Munawaroh, Achmad Haerul Yusro, Jonathan Dwiputra Christian, Aura Dwi Saputri, and Taufiq Hidayat. "Sulfur Removal and Iron Extraction from Natrojarosite Residue of Laterite Nickel Ore Processing by Reduction Roasting." Metals 13, no. 1 (December 24, 2022): 52. http://dx.doi.org/10.3390/met13010052.

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An alternative laterite nickel ore processing using sulfuric acid as a leaching agent to produce class 1 nickel as a raw material for electric vehicle batteries produces natrojarosite residue as a by-product during the precipitation of iron and aluminum step. The natrojarosite residue contained iron and high sulfur, which is challenging to utilize as an iron source for steel manufacturing since sulfur can contaminate the steel product. This study focuses on sulfur elimination and iron extraction from natrojarosite. The natrojarosite was roasted for sulfur removal isothermally at different temperatures ranging from 500 until 1100 °C for 4 h. Roasting at 1100 °C resulted a decrease in sulfur content from 12.18% to 3.81% and an increase in iron content from 16.23% to 28.54%. The sulfur released during roasting can, in principle, be recirculated to a sulfuric acid plant and reused as a leaching agent in the nickel ore processing plant. The unroasted and roasted natrojarosite residues were then reduced by coconut shell charcoal in the temperature range of 1000–1400 °C. The results showed that the metallic iron could be obtained from both unroasted and roasted natrojarosite residue at a temperature of 1200 °C and higher. The sulfur content in the oxide phase of unroasted natrojarosite residue was significantly higher than roasted natrojarosite residue. However, the roasting did not significantly influence the sulfur content in the metal phase. The sulfur content in the metal phase from unroasted and roasted natrojarosite residue was less than 1.2%. This result indicated that the removal of sulfur and metal oxide reduction in the natrojarosite residue could be carried out simultaneously in one stage where the natrojarosite residue is reduced by carbonaceous material at a temperature of 1200 °C or higher.

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Prits, Alise-Valentine, Jaak Nerut, Heili Kasuk, Mihkel Koel, Silver Sepp, Peeter Valk, Jaan Aruväli, et al. "(Digital Presentation) Carbon Aerogel Platinum-Praseodymium Oxide Nanocatalyst for Methanol Oxidation in 0.5 M Sulfuric Acid." ECS Meeting Abstracts MA2022-01, no. 35 (July 7, 2022): 1505. http://dx.doi.org/10.1149/ma2022-01351505mtgabs.

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Electrooxidation of methanol is an essential topic in developing direct methanol fuel cells, and numerous catalyst materials have been studied for this application. 1–3 Among other materials, the platinum-based composite catalysts containing rare earth metal oxides on various support materials have shown promising properties for methanol oxidation and implementation for direct methanol fuel cells.1–3 In this study, platinum-praseodymium oxide nanocatalyst on carbon aerogel support for methanol oxidation was synthesized. The material was electrochemically characterized using rotating disk electrode, cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy methods. X-ray diffraction, specific surface area measurements, thermogravimetric analysis, and high-resolution scanning electron microscopy with energy dispersive X-ray analysis were used to determine the physical properties of the material. The catalyst was synthesized by depositing platinum4 on a pyrolyzed organic aerogel doped with Pr(NO3)3 5,6. Synthesized nanocatalyst material contained 21 wt% of Pt and 20 wt% of PrOx. This material has micro-mesoporous structure with surface area of 230 m2 g−1, micropore area of 70 m2 g−1, total pore volume of 0.62 cm3 g−1 and micropore volume of 0.032 cm3 g−1. Pt and PrOx particles were uniformly dispersed on the supporting carbon aerogel-derived material. Electrochemical measurements showed that the studied material has an electrochemically active surface area of 54 mPt 2 gPt −1, which is noticeably higher than that for commercial Pt-Vulcan catalyst (17 mPt 2 gPt −1) and comparable with similar composite catalyst materials containing rare earth metal oxides (from 45 mPt 2 gPt −1 up to 61 mPt 2 gPt −1).3 For methanol electrooxidation the synthesized material showed high current density peaks in both anodic (310 A gPt −1) and cathodic (240 A gPt −1) potential sweeps. These current densities are higher than measured for commercial Pt-Vulcan catalyst (for the peaks in both anodic (178 A gPt −1) and cathodic (167 A gPt −1) potential sweeps). Furthermore, the synthesized material demonstrated the ability of preserving higher catalytic activity (0.33 A gPt −1) than the commercial Pt-Vulcan catalyst (0.07 A gPt −1) after working on a fixed potential of ‒0.2 V vs RHE for an extended period of time (30 min). While these results outstand the catalytic activity of some similar catalyst materials containing praseodymium,1,7,8 higher current densities on both cathodic and anodic potential sweep have been measured with Pt-PrOx catalyst deposited on carbon black Vulcan XC-72R.3 These characteristics show good suitability of the developed nanocatalyst for methanol oxidation in direct methanol fuel cells. This study shows the potential of nanocatalysts containing rare earth metal oxides and catalyst on the carbon aerogel support for methanol electrooxidation. These materials could be further investigated for the electrooxidation for ethanol or other organic fuels. Acknowlegements This work was supported by the EU through the European Regional Development Fund TK141 “Advanced materials and high-technology devices for energy recuperation systems” (2014-2020.4.01.15-0011), the Estonian Energy Technology Program: SLOKT10209T “Nanomaterials – research and applications (NAMUR)” project 3.2.0304.12-0397and Personal Research Grant PRG676. References Z. Tang and G. Lu, J. Power Sources, 162, 1067–1072 (2006). P. Valk et al., J. Electrochem. Soc., 165, F315–F323 (2018). P. Valk et al., J. Electrochem. Soc., 166, F1062 (2019). C. Galeano et al., J. Am. Chem. Soc., 134, 20457–20465 (2012). K. Kreek, M. Kulp, M. Uibu, A. Mere, and M. Koel, Oil Shale, 31, 185–194 (2014). K. Kreek et al., J. Non-Cryst. Solids, 404, 43–48 (2014). A. O. Neto et al., J. Alloys Compd., 476, 288–291 (2009). L. Chen, J. Hu, and J. S. Foord, Phys. Status Solidi A, 209, 1792–1796 (2012).

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Salazar Peralta, Araceli, Rosa Hilda Chavez, Oscarf Olea Mejía, and Dora Alicia Solís-Casados. "Study of the Corrosion Rate of Three Contactors Materials Using the Electrochemical Technique of Tafel." Advanced Materials Research 356-360 (October 2011): 1195–201. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.1195.

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The main objective of this project was to study the corrosion rate of three different structured packing materials, a metallic, one polymeric and the other one ceramic, which will be in contact with an aqueous solution of MEA (monoethanolamine) to 30% and sour gases in a countercurrent absorption column. The materials were studied in two electrochemical cells: the first one in the presence of an aqueous solution of 1N sulfuric acid, and the second in the aqueous solution of MEA 30%, the study was done using the Tafel extrapolation methods and resistance to the polarization to measure the corrosion current (I Corr), and determine the corrosion rates of the three materials structured packings. The standard procedure used was according to ASTM G59-91, following the technique ININ No. P. SC (Cl) -06, the following results were found: in the presence of 1N sulfuric acid solution the metallic material presented a rate of 7.8 x 10-4 corrosion mpy (miles per year), the polymeric material submitted a corrosion rate of 2.82 x 10-4 mpy, and the ceramic material presented a corrosion rate of 1.03 x 101 mpy. With the aqueous solution of MEA at 30% in weight, and the sour gases the results were as follows: the metallic material presented a corrosion rate of 6.42 x 10-2 mpy, the polymeric material submitted a corrosion rate of 1.48 x 10-1 mpy and the ceramic material presented a corrosion rate of 5.6 x 10-1 mpy. These results provide a basis for predicting the lifetime of the three materials, as well as chemical resistance in the absorption column. Finally, we examined the morphology of the etched surface by scanning electron microscopy and found that in the metallic material was formed a layer of Cr2O3, which is helping the passivating material to further protect the acid attacks, the polymer material has a surface smoother after the attack and in the ceramic is observed pores larger than those observed in the material before the attack.

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KAWASAKI, MASAYUKI. "Recent progress of resources and material technologies.Recent improvements in sulfuric acid plants." Shigen-to-Sozai 113, no. 6 (1997): 457–61. http://dx.doi.org/10.2473/shigentosozai.113.457.

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Varentsov, V. K., and V. I. Varentsova. "Electrochemical modification of a nonwoven fibrous carbon material in sulfuric acid solution." Russian Journal of Applied Chemistry 88, no. 10 (October 2015): 1650–55. http://dx.doi.org/10.1134/s1070427215100158.

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KAWAI, Kenji, Hiroyuki MORITA, Gentaro MURATA, and Yutaka OKAME. "RESISTANCE EVALUATION OF CEMENTITIOUS MATERIAL TO SULFURIC ACID USING SIMPLE TESTING METHOD." Cement Science and Concrete Technology 65, no. 1 (2011): 368–75. http://dx.doi.org/10.14250/cement.65.368.

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Domingos, L. F. T., A. G. S. Azevedo, C. T. Lombardi, and K. Strecker. "Corrosion resistance of fly ash-based geopolymer in hydrochloric and sulfuric acid solutions." Cerâmica 66, no. 380 (December 2020): 394–403. http://dx.doi.org/10.1590/0366-69132020663802927.

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Abstract Currently, there is a growing interest in the use of industrial waste as a raw material in obtaining and developing new products in order to meet technological and environmental demands. Fly ash, for example, when in contact with an alkaline medium, forms inorganic polymers or geopolymers, which have properties comparable to ordinary Portland cement (OPC), but are capable of reducing up to 95% of CO2 emission into the atmosphere. In this study, the corrosion resistance of a geopolymer produced by the alkaline activation of fly ash type F was evaluated in 3%, 6%, and 9% hydrochloric and sulfuric acid solutions for up to 28 days. The materials showed an average loss in terms of compressive strength of approximately 29,8% and 39,5% after 28 days of immersion in HCl and H2SO4, respectively. The immersion in HCl showed divergent results due to the formation of NaCl crystals around the microstructure of the material.

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Kumar, N. Venkata Sairam, J. Usha Kranti, and U. V. Narayana Rao. "Resistance of Wood Ash Concrete to Sulfuric Acid Attack." Oriental Journal Of Chemistry 38, no. 4 (August 31, 2022): 1047–52. http://dx.doi.org/10.13005/ojc/380429.

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This paper is aimed to present the residual compressive strength of wood ash (WA) concrete cube specimens after immersion in diluted sulfuric acid (H2SO4) solutions. The sulfuric acid resistance of WA concrete is observed using 2% and 5% H2SO4 solutions. WA is used as mineral admixture and the partial substitution levels of WA are 0% (CW0), 5% (CW5), 10% (CW10), 15% (CW15), and 20% (CW20) by weight of 53 grade Portland cement. WA concrete results are compared with the results of M30 grade concrete (CW0). At CW5 and CW10 replacement levels, a slight enhancement in the strength of WA concrete is noticed. No significant resistance to H2SO4 is observed with WA concrete when compared with CW0 concrete. Further, the deterioration of CW0, CW5, and CW10 concrete is similar. The substitution of WA with cement reduces the cement content and eventually gives fewer hydrated cementitious products that enable deterioration by H2SO4. Furthermore, WA helps in improving the density and filling capacity of the interaction transition zone of concrete which leads to the reduction of pores and capillary action. In brief, the use of WA in concrete benefits by converting environmental concern material into a sustainable resource in producing cementing materials.

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Wanna, Surachet, Warangkana Saengsoy, Pisanu Toochinda, and Somnuk Tangtermsirikul. "Effects of Sand Powder on Sulfuric Acid Resistance, Compressive Strength, Cost Benefits, and CO2 Reduction of High CaO Fly Ash Concrete." Advances in Materials Science and Engineering 2020 (December 27, 2020): 1–12. http://dx.doi.org/10.1155/2020/3284975.

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This article studies the efficiency of sand powder as a supplementary cementitious material (SCM) in improving the sulfuric acid resistance of concrete incorporated with high CaO fly ash. Besides, the effects of sand powder on compressive strength development, mitigation of carbon dioxide emission, and cost-effectiveness are addressed. Paste mixtures with W/B ratios of 0.25 and 0.40 were used in this study for the performances of sulfuric acid resistance and long-term compressive strength development. The test results indicated that sand powder could reduce the weight loss of the tested paste specimens in sulfuric acid solution with a pH of 1, compared to the control specimens, especially for the specimens incorporated with high CaO fly ash. The sand powder addition could also increase the compressive strength of cement pastes at the age of 90 days by 26.27% and 43.80% for W/B ratios of 0.25 and 0.40, respectively. The use of sand powder in the evaluated concrete mixture could also reduce CO2 emission by 23.23% and lower the cost of the mixtures by 8.05%, compared to the control mixture. The addition of sand powder could significantly increase the sulfuric acid resistance, compressive strength, and economic benefits and reduce the CO2 emission of high CaO fly ash-cement-based materials.

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Viet Duc, N. "Experimental Water Quality Analysis from the Use of High Sulfuric Fly Ash as Base Course Material for Road Building." Engineering, Technology & Applied Science Research 9, no. 5 (October 9, 2019): 4627–30. http://dx.doi.org/10.48084/etasr.2991.

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Water quality directly influences human life. Drinking water contamination can result in severe health problems. This paper deals with the analysis of water specimens from submergence of material containing high sulfuric fly ash as base course material for road building. The specimens were obtained from real road testing. Results showed that for the material that used fly ash and chemical admixture, water quality was suitable for drinking in accordance with the standard parameters prescribed by the Vietnam Ministry of Health, while for the material that used the same fly ash without chemical admixture, the total arsenic content was eight times higher than that of the former. Thus, if one desires to utilize fly ash with high sulfur as base course material for road building, it needs to be used in combination with appropriate chemical admixture, so that it would not affect ground water quality.

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Korkmaz, Kivanc, Mahmood Alemrajabi, Åke Rasmuson, and Kerstin Forsberg. "Sustainable Hydrometallurgical Recovery of Valuable Elements from Spent Nickel–Metal Hydride HEV Batteries." Metals 8, no. 12 (December 14, 2018): 1062. http://dx.doi.org/10.3390/met8121062.

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In the present study, the recovery of valuable metals from a Panasonic Prismatic Module 6.5 Ah NiMH 7.2 V plastic casing hybrid electric vehicle (HEV) battery has been investigated, processing the anode and cathode electrodes separately. The study focuses on the recovery of the most valuable compounds, i.e., nickel, cobalt and rare earth elements (REE). Most of the REE (La, Ce, Nd, Pr and Y) were found in the anode active material (33% by mass), whereas only a small amount of Y was found in the cathode material. The electrodes were leached in sulfuric acid and in hydrochloric acid, respectively, under different conditions. The results indicated that the dissolution kinetics of nickel could be slow as a result of slow dissolution kinetics of nickel oxide. At leaching in sulfuric acid, light rare earths were found to reprecipitate increasingly with increasing temperature and sulfuric acid concentration. Following the leaching, the separation of REE from the sulfuric acid leach liquor by precipitation as NaREE (SO4)2·H2O and from the hydrochloric acid leach solution as REE2(C2O4)3·xH2O were investigated. By adding sodium ions, the REE could be precipitated as NaREE (SO4)2·H2O with little loss of Co and Ni. By using a stoichiometric oxalic acid excess of 300%, the REE could be precipitated as oxalates while avoiding nickel and cobalt co-precipitation. By using nanofiltration it was possible to recover hydrochloric acid after leaching the anode material.

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Ibrahim, Baraa Khalil. "The study of the bending property of the epoxy (Ep / MgO) and (Ep/SiO2) composites in natural conditions and after immersion in chemical solution." Iraqi Journal of Physics (IJP) 16, no. 39 (January 5, 2019): 93–102. http://dx.doi.org/10.30723/ijp.v16i39.107.

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In this paper, a polymer-based composite material was prepared by hand Lay-up method consisting of epoxy resin as a base material reinforced by magnesium oxide powder once and silicon dioxide powder again and with different weight ratios (3, 6, 9 and 12) wt %. The three-point bending test was performed in normal conditions and after immersion in sulfuric acid. The results showed that the bending value decreased with the increase of the weighted ratio of the reinforcement material (MgO, SiO2). The Bending of samples reinforced by SiO2 was found to be less than the bending of samples reinforced by particles (MgO). For example, the bending of the SiO2 sample (0.32 mm) at the weighted ratio (3%) and for the MgO (0.18mm) sample at the weight ratio were the same weighted load (100 g). It was found that the bending values of all samples exceeded the value after immersion in sulfuric acid. For example, the percentage of weight (6%) at the load level (500 g) was changed from 1.16 mm in normal conditions to 1.48mm for the same weight ratio after immersion. In sulfuric acid diluted with 0.3N for 10 days at the same applied load.

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Pei, Xinya, Xiaoxue Liu, Xiaoyu Liu, Jinling Shan, Hui Fu, Ying Xie, Xuemin Yan, et al. "Synthesis of Hierarchical Titanium Silicalite-1 Using a Carbon-Silica-Titania Composite from Xerogel Mild Carbonization." Catalysts 9, no. 8 (August 7, 2019): 672. http://dx.doi.org/10.3390/catal9080672.

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Hierarchical titanium silicalite-1 (HTS-1) zeolites are an important class of catalytic materials due to their enhanced mass transfer and improved catalytic performance. In this study, HTS-1 zeolites have been successfully prepared by the hydrothermal crystallization of carbon-silica-titania (CST) composites. Compared with the direct carbonization method, the mild carbonization of SiO2-TiO2/Tween 40 xerogel in the presence of sulfuric acid can effectively improve both the content and mesoporous structure of carbon material in the CST composites, which enables carbon materials to better play the role of a mesoporous template during the crystallization process. The resultant zeolite has both ordered micropores and interconnected mesopores and macropores, which are similar to the skeleton of the carbon template trapped in the TS–1 crystals. Moreover, the HTS–1 zeolite displays outstanding catalytic performance in oxidative desulfurization of bulky sulfur compounds.

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Woytowich, David L., Martin W. King, Myron G. Britton, and Jan A. Oleszkiewicz. "Accelerated testing of a filled polyester E-glass composite in acidic environments." Canadian Journal of Civil Engineering 18, no. 5 (October 1, 1991): 799–809. http://dx.doi.org/10.1139/l91-097.

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This paper describes the results of an accelerated laboratory investigation to measure the rate of deterioration of a newly developed filled plastic composite exposed to acidic (sewage) environments. The specific objective was to compare the relative rates of deterioration of an experimental filled filament wound (FFW) polyester composite immersed in sulfuric (pH 2.23) and acetic (pH 2.22) acid environments at 45 °C. Deterioration was measured in terms of changes in wet specimen weight, loss in dried (soluble) material weight and mechanical properties, the extent of chemical dissolution, and the depth of penetration. Based on regression analyses of these parameters, it was found that the rate of deterioration was a function of the square root of immersion time. Deterioration of the FFW composite in acetic acid was 1.6–3.9 times greater than in the sulfuric acid environment. The loss in wet flexural properties and the dissolution behavior of aluminum trihydrate were not influenced by the type of acid environment. Based on the findings of this study, sulfuric acid is recommended as a standard laboratory test medium for fiberglass reinforced plastic composites used in construction of sewage facilities and pipelines where deterioration due to sulfur oxidizing bacteria is anticipated. Key words: accelerated, polyester, fillers, filament-wound, environment, acidic, durability, composite, septic tanks.

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Utami, Maisari, Karna Wijaya, and Wega Trisunaryanti. "Effect of Sulfuric Acid Treatment and Calcination on Commercial Zirconia Nanopowder." Key Engineering Materials 757 (October 2017): 131–37. http://dx.doi.org/10.4028/www.scientific.net/kem.757.131.

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The modification of commercial zirconia nanopowder by sulfuric acid and heat treatment was conducted. The aim of this present research was to obtain a stable modified zirconia nanopowder chemically and thermally by studying the effect of sulfuric acid treatment and calcination temperature on commercial zirconia nanopowder. The material was prepared by dispersing the commercial zirconia nanopowder into 0.2, 0.5 and 0.8 M sulfuric acid solutions, followed by calcination at varied temperatures, i.e. 600, 700, 800 and 900 °C. The so called sulfated zirconias then were characterized their physicochemical properties using FT-IR, XRD and SEM-EDX analysis methods. The optimized condition for that modification was obtained by using sulfuric acid of 0.8 M and calcination temperature of 600 °C. The characterization results also revealed that using ammonia adsorption method, the acidity of the catalyst was found to be 1.06 mmol/g.

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Meryanalinda, Meryanalinda, Dedy Rachman Ardian, Mochammad Shocib, and Ahmad Yasin. "ANALYSIS OF CORROSION RATE OF ASTM A 387 GRADE 12 AND A 283 GRADE FOR SULFURIC ACID TANK MATERIAL." Journal of Applied Sciences, Management and Engineering Technology 1, no. 2 (November 23, 2020): 50–57. http://dx.doi.org/10.31284/j.jasmet.2020.v1i2.1194.

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Corrosion is a process of degradation metal quality which is very detrimental in the industry. Especially in an industries related to utilization of acidic liquids such assulfuric acid, hydrochloric acid, etc. If corrosion rate of carbon steel can be estimated, the prediction of remaining life of carbon steel, and the preventive methods of corrosionwould be more appropriate. This will reduce technical, economic and aesthetic losses. The aims of this study was to determine corrosion rate of carbon steel in sulfuric acid. This study used ASTM A 387 Grade 12 and ASTM A 283 Grade A carbon steel type fortank material, where one material is represented by 5 specimen. The corrosion rate of Specimens were measured by the weight loss method for 31 days. The 5 specimens were divided into 3 regions where specimens no.1 and 2 were immersed in sulfuric acid , specimens no.3 were in the middle area or zone level (partially immersed), and specimens no.4 and 5 were not immersed in sulfuric acid. The highst corrosion rate occured on specimen No.3 with maximum corrosion rate was 0,097 mm/y for ASTM A 387 Gr 12 and 0,096 mm/y untuk material ASTM A 283 Gr A. The results of corrosion rate on ASTM A 387 Grade 12 material are lower than corrosion rate of ASTM A 283 Grade A material. This is caused by presence of Mo and Cr alloy elements in ASTM A 387 Grade 12.

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Rizaldi, Niko, Habib Abdurrahman, Miguel Felix Wijaya, Gunawan Wibisono, and Monita Olivia. "Durability of Fly Ash Geopolymer Hybrid Concrete in Seawater, Sulfuric Acid, and Fire Resistant – A Review." Journal of Physics: Conference Series 2049, no. 1 (October 1, 2021): 012088. http://dx.doi.org/10.1088/1742-6596/2049/1/012088.

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Abstract Fly ash is a hazardous and toxic waste material from burning coal. However, it can be used as a material of geopolymer concrete because it contains high amounts of silica and alumina. Recent research on geopolymer concrete is still being conducted because it is part of green building material. This review aims to determine and analyzed the durability of fly ash geopolymer hybrid concrete in aggressive environments. The environment studied included seawater, sulfuric acid, and elevated temperature. OPC concrete is a high calcium material; therefore it is susceptible to aggressive environments compared with OPC concrete, geopolymer concrete contains aluminosilicate and low calcium material, which is not reactive with aggressive environment. The method used in this study is a literature review of several relevant research sources, and data were collected and analyzed. The results showed that fly ash geopolymer hybrid concrete had increase compressive strength compared to OPC concrete. In the seawater environment, the compressive strength of geopolymer concrete increases from 10%-15%. The compressive strength of geopolymer concrete also increases in a sulfuric acid environment up to 360 days of test age, and it is resistant to fire up until 800 °C. Likewise, the porosity of the geopolymer fly ash concrete decreased while the OPC concrete increased. According to the analysis and discussion results, it was resumed that fly ash geopolymer concrete is more environmentally friendly and durable than OPC concrete, especially in seawater, sulfuric acid, and post-fire environments.

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Schippers, Axel. "Bioleaching of Copper Slag Material." Solid State Phenomena 262 (August 2017): 61–64. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.61.

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Bioleaching is applied mainly for copper recovery from low-grade sulfide ores via heap leaching. The main copper processing route includes pyrometallurgy and the remaining copper slag from smelting may still contain copper in amounts found in the ore. Here bioleaching of copper slag material with a copper content of about 1 % (grain size < 63 µm) and fayalite (Fe2SiO4) und magnetite (Fe3O4) as main mineral phases was tested in aerobic shake flask experiments with a mixed culture of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidiphilium spp..To additionally test for reductive bioleaching, experiments under anaerobic conditions (80% N2, 20% CO2, v/v) with or without addition of elemental sulfur were run. The pH was adjusted to < 3 by addition of sulfuric acid. After the incubation period of more than 50 days at 30°C cell growth was observed in all biological assays. The redox potential was above 800 mV SHE in the aerobic biological assays and dropped to around 500 mV in the chemical control assays as well as in the anaerobic biological and chemical assays. A significant copper bioleaching was observed in the aerobic experiments with 91 % copper release (max. 35 % in the chemical controls). Anaerobic bioleaching experiments did not show a significant copper release, however the release of iron (as iron(II)) and sulfate was much higher than in the abiotic assays and several fold higher than in the classical aerobic bioleaching experiments. Overall the results show that copper bioleaching from slag material is possible, however the economic feasibility needs to be demonstrated.

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Gurzęda, B., T. Buchwald, M. Nocuń, A. Bąkowicz, and P. Krawczyk. "Correction: Graphene material preparation through thermal treatment of graphite oxide electrochemically synthesized in aqueous sulfuric acid." RSC Advances 8, no. 34 (2018): 19237. http://dx.doi.org/10.1039/c8ra90043d.

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Herisson, J., M. Guéguen-Minerbe, E. D. van Hullebusch, and T. Chaussadent. "Behaviour of different cementitious material formulations in sewer networks." Water Science and Technology 69, no. 7 (January 28, 2014): 1502–8. http://dx.doi.org/10.2166/wst.2014.009.

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Sewer networks are subjected to degradation, including biodeterioration of materials, in the presence of biogenic sulfuric acid, leading to costly repairs. To ensure durable structures, it is essential to select the best adapted materials. Two cementitious materials based on ordinary Portland cement (OPC) or calcium aluminate cement (CAC), were subjected to biodeterioration in the headspace of an operating sewer network. After a few month OPC materials started to deteriorate whereas CAC materials were still intact. The better durability of CAC materials is due to the presence of alumina providing a combination of protective mechanisms. On-site environmental parameters were monitored and analysed in the context of the biological and chemical mechanisms involved in material degradation. These data will eventually feed into the development of a representative, reproducible and accelerated laboratory test.

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Kuwata, Mikinori, Yingjun Liu, Karena McKinney, and Scot T. Martin. "Physical state and acidity of inorganic sulfate can regulate the production of secondary organic material from isoprene photooxidation products." Physical Chemistry Chemical Physics 17, no. 8 (2015): 5670–78. http://dx.doi.org/10.1039/c4cp04942j.

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Cho, Yeonchul, Kihun Kim, Jaewoo Ahn, and Jaeheon Lee. "A Study on Lithium Hydroxide Recovery Using Bipolar Membrane Electrodialysis." Korean Journal of Metals and Materials 59, no. 4 (April 5, 2021): 223–32. http://dx.doi.org/10.3365/kjmm.2021.59.4.223.

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Bipolar electrodialysis was used in a process of desalting a lithium sulfate solution, converting it to lithium hydroxide and sulfuric acid, and concentrating and recovering them. The effects of the experimental variables such as applied voltage, the concentration of electrode solution, the concentration of raw material solution, volume ratio, and impurity were confirmed. The optimum conditions were investigated by comparing the conversion(%) of lithium hydroxide and sulfuric acid, the process time, and energy consumption. As the applied voltage was increased, the energy consumption tended to increase, but the processing time decreased significantly. As the concentration of lithium sulfate in the raw material solution increased, the conversion(%) of lithium hydroxide decreased. As the concentration of lithium sulfate increased, the energy consumption did not increase linearly, and energy consumption increased significantly. When a raw material solution of 0.5 M Li2SO4 or more is used in the bipolar electrodialysis process, an applied voltage of 25 V is preferable. As the applied voltage increased at a constant process time, the conversion(%) of LiOH and H2SO4 increased. Regarding the effect of the electrode solution concentration, when a 5.0 wt% electrode solution was used rather than a 3.0 wt% electrode solution, energy consumption decreased by more than 10%. When the volume of the raw material solution was increased, the processing time required for desalting increased. By using a low concentration raw material solution, it was confirmed that it was simultaneously possible to recover and concentrate lithium hydroxide and sulfuric acid through volume ratio control. When the raw material solution contained Na as an impurity, it was converted to NaOH with a surface LiOH, and it was not possible to separate the lithium and sodium.

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Bai, Shao Jun, Shu Ming Wen, Jiu Shuai Deng, Dan Liu, and Yu Chen. "Comprehensive Utilization of Sulfuric Acid Residue with High Content of Copper by Pellet Production-Drying-Chloridizing Roasting." Advanced Materials Research 524-527 (May 2012): 2004–10. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.2004.

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A new technology of pellet production-drying-chloridizing roasting is proposed for comprehensive utilization of sulfuric acid residue with high content of copper, a common by-product in vitriol industry. The sulfuric acid residue, containing 60.27% Fe, and 1.61% Cu, was pelletized with addition of 5% bentonite in pan pelletizer. Green balls after drying with 2.3% of water retention were roasting at 1100 °C for 30 min with 5 wt % of CaCl2addition in tube furnace. The results demonstrate that pellets with 60.58% of TFe, a copper volatite ratio of 97.8% were obtained with simultaneous decrease in the copper content down to 0.035%. Key technique is that CaCl2reacts with copper compounds and the chloride can be volatilized at moderate temperatures. This new technology can be used to fully utilize sulfuric acid residue and produce qualified concentrate as iron-bearing feed for steel industry, which will help to solve the pollution of sulfuric acid residue and extend raw material sourcing for Chinese steel industry.

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Journal articles on the topic 'Sulfuric material'

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