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Academic literature on the topic 'Cyanide proces'

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Published: 4 June 2021
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Journal articles on the topic "Cyanide proces"

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Luque-Almagro, Víctor M., María-J. Huertas, Manuel Martínez-Luque, Conrado Moreno-Vivián, M. Dolores Roldán, L. Jesús García-Gil, Francisco Castillo, and Rafael Blasco. "Bacterial Degradation of Cyanide and Its Metal Complexes under Alkaline Conditions." Applied and Environmental Microbiology 71, no. 2 (February 2005): 940–47. http://dx.doi.org/10.1128/aem.71.2.940-947.2005.

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ABSTRACT A bacterial strain able to use cyanide as the sole nitrogen source under alkaline conditions has been isolated. The bacterium was classified as Pseudomonas pseudoalcaligenes by comparison of its 16S RNA gene sequence to those of existing strains and deposited in the Colección Española de Cultivos Tipo (Spanish Type Culture Collection) as strain CECT5344. Cyanide consumption is an assimilative process, since (i) bacterial growth was concomitant and proportional to cyanide degradation and (ii) the bacterium stoichiometrically converted cyanide into ammonium in the presence of l-methionine-d,l-sulfoximine, a glutamine synthetase inhibitor. The bacterium was able to grow in alkaline media, up to an initial pH of 11.5, and tolerated free cyanide in concentrations of up to 30 mM, which makes it a good candidate for the biological treatment of cyanide-contaminated residues. Both acetate and d,l-malate were suitable carbon sources for cyanotrophic growth, but no growth was detected in media with cyanide as the sole carbon source. In addition to cyanide, P. pseudoalcaligenes CECT5344 used other nitrogen sources, namely ammonium, nitrate, cyanate, cyanoacetamide, nitroferricyanide (nitroprusside), and a variety of cyanide-metal complexes. Cyanide and ammonium were assimilated simultaneously, whereas cyanide strongly inhibited nitrate and nitrite assimilation. Cyanase activity was induced during growth with cyanide or cyanate, but not with ammonium or nitrate as the nitrogen source. This result suggests that cyanate could be an intermediate in the cyanide degradation pathway, but alternative routes cannot be excluded.
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RAMIREZ, CARLOS DARIO LOPEZ, DAIRO E. CHAVERRA, and OSCAR JAIME RESTREPO BAENA. "Obtaining Urea from Effluents of Gold Cyanidation Process." Material Science Research India 16, no. 1 (April 23, 2019): 43–47. http://dx.doi.org/10.13005/msri/160106.

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Cyanide is one of the most used reagents in the precious metal extraction process; as well as the most efficient from the point of view of the dissolution process, but it is also a toxic product that requires a lot of care in handling. Likewise, the residual solutions of the process must be followed because they can be a risk of contamination of water, animals and human health. In the artisanal processes of obtaining gold and silver, neutralization of the residual solutions is used to passivate the present cyanide. During this process ammonium cyanate is formed which decomposes rapidly in the presence of air and sunlight in carbon dioxide and ammonia gas, contributing to the greenhouse effect. In this work, the use of the ammonium cyanate obtained in the process of neutralization of the cyanide solutions as a reagent to obtain urea is proposed. Urea was obtained indirectly through the use of the reagent kit UREA/BUN-COLOR. The process is effective at pH ≤ 4.5 with a rapid increase in solution temperature and the addition of hydrogen peroxide. The urea crystals begin to form at 50°C. The cyanide/urea ratio obtained was 1/7.5.
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Mitsudo, Koichi, Kazuki Yoshioka, Takayuki Hirata, Hiroki Mandai, Koji Midorikawa, and Seiji Suga. "1,10-Phenanthroline- or Electron-Promoted Cyanation of Aryl Iodides." Synlett 30, no. 10 (April 11, 2019): 1209–14. http://dx.doi.org/10.1055/s-0037-1611793.

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A 1,10-phenanthroline-promoted cyanation of aryl iodides has been developed. 1,10-Phenanthroline worked as an organocatalyst for the reaction of aryl iodides with tetraalkylammonium cyanide to afford aryl cyanides. A similar reaction occurred through an electroreductive process.
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Simovic, L., and W. J. Snodgrass. "Natural Removal of Cyanide in Gold Milling Effluents - Evaluation of Removal Kinetics." Water Quality Research Journal 20, no. 2 (May 1, 1985): 120–35. http://dx.doi.org/10.2166/wqrj.1985.023.

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Abstract Research using synthetic solutions was conducted to examine factors influencing the natural removal of cyanides from gold mill lagoons. Factors examined included: pH, temperature, ultraviolet irradiation and degree of aeration. Temperature was the principal factor affecting the rate of cyanide loss from solution. UV irradiation had some effect while the effect of aeration was limited. The dominant mechanism for cyanide removal from solution was volatilization. Cyanide degradation was found to follow a first order reaction with respect to free cyanide and metallo-cyanide complexes of Zn, Ni, Cu and Fe. Data from each single metallo-cyanide solution were fitted to a mathematical model which considered volatilization of free cyanide, dissociation of the metallo-cyanide species, and one cyanide complex per metal. The best estimates of the rate constants found for the single metallo-cyanide solutions were used to simulate the removal characteristics of cyanide in a synthetic mixed solution of four metals. The coefficient of determination ranged from 0.93 to 0.99 for model predictions fitted to data from single metallo-cyanide solutions. Estimates for volatilization coefficients varied widely with some of the variation resulting from data which did not completely describe the decay process. The simulation of cyanide removal from the synthetic mixed solution suggested the need to recalibrate the model or to examine the formation of more than one metallo-cyanide species.
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Beattie, JK, and GA Polyblank. "Copper-Catalyzed Oxidation of Cyanide by Peroxide in Alkaline Aqueous Solution." Australian Journal of Chemistry 48, no. 4 (1995): 861. http://dx.doi.org/10.1071/ch9950861.

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The oxidation of cyanide by peroxide in alkaline aqueous solution is catalysed by copper complexes. In the presence of excess cyanide, copper(II) is reduced to form the tricyanocuprate (I) complex. The cyanogen oxidation product is hydrolysed with disproportionation to cyanate and cyanide:2CuII+2CN-→ 2CuI+(CN)2(CN)2+2OH- → OCN-+CN-+H2OCuI+3CN- ↔ Cu(CN)32-The stoichiometry and kinetics of the catalysed oxidation have been investigated. Hydrogen peroxide oxidizes coordinated cyanide with a rate that is first order in peroxide and first order in copper but independent of cyanide concentration in the presence of excess cyanide. Cu(CN)32-+H2O2→ Cu(CN)2-+OCN-+H2O Cu(CN)2-+CN-↔ Cu(CN)32- When the excess cyanide is consumed and Cu(CN)2- becomes the dominant species, the reaction becomes more complex and less efficient. Under certain conditions the stoichiometry revealed a peroxide-to-Cu(CN)2- ratio of about 6 : 1, instead of the minimum of 2.5:1 required for the oxidation of the coordinated cyanide to cyanate and the CuI to Cu(OH)2. This suggests that peroxide is consumed by a copper- catalysed disproportionation, in competition with oxidation of the coordinated cyanide. An intermediate yellow complex forms while peroxide is present, before Cu(OH)2 finally precipitates. The consequence of this mechanism is that the most efficient process for the destructive oxidation of cyanide has a high cyanide-to-copper ratio, to minimize the final concentration of Cu(CN)2- which consumes peroxide inefficiently. The rate of the reaction depends on the concentration of copper, however, which must be large enough for a satisfactory turnover.
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Dong, Kaiwei, Feng Xie, Wei Wang, Yongfeng Chang, Chunlin Chen, and Xiaowei Gu. "Calcination of Calcium Sulphoaluminate Cement Using Pyrite-Rich Cyanide Tailings." Crystals 10, no. 11 (October 26, 2020): 971. http://dx.doi.org/10.3390/cryst10110971.

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Pyrite-rich cyanide tailings (CTs) are industrial hazardous solid wastes arising from the gold mining industry. Every year, hundreds of millions of tons of cyanide tailings are produced and discharged to tailings dams. It is of great significance to dispose of cyanide tailings harmlessly and resourcefully. The feasibility of calcination of calcium sulphoaluminate (CSA) cement clinker using pyrite-rich cyanide tailings as Fe2O3 and SO3 sources was investigated for this paper. The behavior of pyrite during the calcination of cyanide tailings under various calcination conditions and the properties of calcium sulphoaluminate cement clinker were examined. The results show that it is feasible to produce calcium sulphoaluminate cement clinker using pyrite-rich cyanide tailings. The optimal conditions for the calcination of calcium sulphoaluminate cement using pyrite-rich cyanide tailings are confirmed. During the calcination process, the cyanides decompose into carbonate, CO2, and N2. The pyrite decomposes into Fe2O3 and SO2, and they react with CaO and Al2O3 to form the intermediates of CaSO4, 2CaO·Fe2O3, and CaO·2Al2O3, which further react to form 3CaO·3Al2O3·CaSO4, 4CaO·Al2O3·Fe2O3, and 12CaO·7Al2O3. The calcium sulphoaluminate cement prepared by pyrite-rich cyanide tailings exhibits excellent mechanical properties and meets the compressive strength criteria of 42.5 grade calcium sulphoaluminate cement.
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Singh, Hariraj, and Brijesh Kumar Mishra. "Degradation of cyanide, aniline and phenol in pre-treated coke oven wastewater by peroxide assisted electro-oxidation process." Water Science and Technology 78, no. 10 (December 10, 2018): 2214–27. http://dx.doi.org/10.2166/wst.2018.503.

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Abstract The present study explored the feasibility of using graphite electrodes for the electrochemical oxidation of cyanide, thiocyanate, phenol and aniline with hydrogen peroxide. The dosing effects of hydrogen peroxide and current density were examined in the pre-treated coke oven wastewater. It was found that 0.025 M hydrogen peroxide and 13.63 mA/cm2 of current density were more favorable for the removal of 100%, 90%, 71% and 40% cyanide, thiocyanate, phenol and aniline respectively. The increased removal of phenol in the coke oven wastewater was attributed to the pre-treatment of wastewater. Initially, 28% phenol was converted to phenolate ion by air stripping process, which increased the removal rate of phenol by the electro-oxidation process as the removal of phenolate is quite easy compared to phenol. The advanced oxidation process degrades the more toxic cyanide into less toxic intermediate cyanate ions (CNO─), which further cut down into nontoxic end products such as N2, HCO3 and CO2. The experimental results show that the primary mechanisms in the oxidation of cyanide and phenol are mediated electro-oxidation by hydroxyl radicals and hypochlorite ions. The operating cost under the optimized conditions for the removal of 100% cyanide and 71% phenol was estimated to be 616.95 INR/m3.
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Levitus, Marcia, and Suman Ranjit. "Cyanine dyes in biophysical research: the photophysics of polymethine fluorescent dyes in biomolecular environments." Quarterly Reviews of Biophysics 44, no. 1 (November 26, 2010): 123–51. http://dx.doi.org/10.1017/s0033583510000247.

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AbstractThe breakthroughs in single molecule spectroscopy of the last decade and the recent advances in super resolution microscopy have boosted the popularity of cyanine dyes in biophysical research. These applications have motivated the investigation of the reactions and relaxation processes that cyanines undergo in their electronically excited states. Studies show that the triplet state is a key intermediate in the photochemical reactions that limit the photostability of cyanine dyes. The removal of oxygen greatly reduces photobleaching, but induces rapid intensity fluctuations (blinking). The existence of non-fluorescent states lasting from milliseconds to seconds was early identified as a limitation in single-molecule spectroscopy and a potential source of artifacts. Recent studies demonstrate that a combination of oxidizing and reducing agents is the most efficient way of guaranteeing that the ground state is recovered rapidly and efficiently. Thiol-containing reducing agents have been identified as the source of long-lived dark states in some cyanines that can be photochemically switched back to the emissive state. The mechanism of this process is the reversible addition of the thiol-containing compound to a double bond in the polymethine chain resulting in a non-fluorescent molecule. This process can be reverted by irradiation at shorter wavelengths. Another mechanism that leads to non-fluorescent states in cyanine dyes is cis–trans isomerization from the singlet-excited state. This process, which competes with fluorescence, involves the rotation of one-half of the molecule with respect to the other with an efficiency that depends strongly on steric effects. The efficiency of fluorescence of most cyanine dyes has been shown to depend dramatically on their molecular environment within the biomolecule. For example, the fluorescence quantum yield of Cy3 linked covalently to DNA depends on the type of linkage used for attachment, DNA sequence and secondary structure. Cyanines linked to the DNA termini have been shown to be mostly stacked at the end of the helix, while cyanines linked to the DNA internally are believed to partially bind to the minor or major grooves. These interactions not only affect the photophysical properties of the probes but also create a large uncertainty in their orientation.
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Rader, W. Scott, Ljiljana Solujic, E. B. Milosavljevic, J. L. Hendrix, and J. H. Nelson. "Photochemistry of Aqueous Solutions of Dicyanomercury(II) and Potassium Tetracyanomercurate(II)." Journal of Solar Energy Engineering 116, no. 3 (August 1, 1994): 125–29. http://dx.doi.org/10.1115/1.2930070.

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Photochemically induced reactions of dicyanomercury(II) and potassium tetracyanomercurate(II) in alkaline aqueous solutions were investigated in detail. The studies were conducted in the presence or absence of a titanium(IV) oxide semiconductor photocatalyst utilizing sunlight as the irradiation source. It was established that the cyanide ion liberated from the thermodynamically stable mercury-cyano species can be photocatalytically oxidized via cyanate and nitrite to nitrate. In addition, the process removes over 99 mol% of mercury from the solution. In the absence of the photocatalyst, no photoproducts were detected and mercury remained in solution. The results obtained may have ramifications for the use of solar power for the efficient treatment of large quantities of precious metals mill tailings wastes containing various cyanide species. In addition, in order to follow the fate of cyanide in these experiments, a novel gas-diffusion flow injection analysis system for the determination of cyanide from the thermodynamically stable mercury-cyano complexes was utilized.
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Ofori-Sarpong, G., A. S. Adam, and R. K. Amankwah. "Detoxification of Cyanide Wastewater by Cyanotrophic Organisms: the case of Phanerochaete chrysosporium." Ghana Mining Journal 20, no. 1 (July 7, 2020): 34–44. http://dx.doi.org/10.4314/gm.v20i1.4.

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Abstract Cyanide, a carbon-nitrogen radical, is a major building block in many industries including pharmaceuticals, petrochemical and gold processing. In the gold extraction industry, cyanide has been the universal lixiviant for over a century due to better understood process chemistry, among others. Industries that discharge cyanide-laden effluents are mandated to keep concentrations below 0.2 mg/L to prevent death by cyanide-intoxification, which occurs when cyanide binds to key iron-containing enzymes and prevent them from supplying oxygen-containing blood to the tissues. Techniques used to attenuate cyanide in wastewater can broadly be grouped into chemical, physical and biological methods. In recent times, attention has been placed on biotechnological methods, which make use of cyanotrophic microorganisms to clean up cyanide-contaminated environments. This paper reports on studies set out to assess the ability of Phanerochaete chrysosporium to degrade cyanide under different conditions including changes in cyanide concentration, culture mass, time, closed system and open system. At the end of 24-hour contact in an open agitated system with initial pH of 11.5, a control experiment using 100 mg/L cyanide revealed a natural attenuation of 15% with pH decreasing to 9.88, while the best myco-detoxification of 85% was achieved by contacting 100 mg/L cyanide with 0.5 g culture mass, translating into degradation capacity of 17.2 mg/g (milligram of cyanide per gram of culture) with pH reducing to 8.4 in 24 hours. The degradation could be based on a number of mechanisms including hydrolysis to HCN, oxidation to cyanyl radical and cyanate due to natural attenuation through atmospheric contact, and secretion of organic acid, oxidative enzymes, and hydrogen peroxide by the fungus. Keywords: Cyanotrophic Organism, Myco-Detoxification, Cyanide-Laden Effluents, pH
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Dissertations / Theses on the topic "Cyanide proces"

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Jayasinghe, Nivari School of Chemical Engineering &amp Industrial Chemistry UNSW. "Ion exchange equilibria of the gold cyanide complex in aqueous and mixed solvent environments." Awarded by:University of New South Wales. School of Chemical Engineering and Industrial Chemistry, 2005. http://handle.unsw.edu.au/1959.4/23056.

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Ion exchange equilibria are presented for [ ]??? ??? Au(CN)2 / Cl , [ ]??? ??? Au(CN)2 / SCN and SCN??? / Cl??? in aqueous solution, and in various mixed solvents, at 303K using Purolite A500 as the ion-exchanger. The mixed solvents investigated include water-acetone, water-dimethylsulfoxide (DMSO) and water-N-methyl-2-pyrrolidone (NMP). In aqueous solution, the selectivity of Purolite A500 for a given anion increases in the order: [ ]??? ??? < ??? < Cl SCN Au(CN)2 . This selectivity sequence confirms the high affinity of the ion exchange resin for the [ ]??? Au(CN)2 species. In mixed solvents, however, the selectivity of Purolite A500 for [ ]??? Au(CN)2 decreases with an increase in the composition of the organic solvent in the external solution. Mixed solvents containing greater than 60 mol% organic solvent are preferred for the displacement of [ ]??? Au(CN)2 from the resin. The effectiveness of a given type of mixed solvent generally increases in the following order: DMSO &it acetone &it NMP. The ion exchange equilibria are correlated using the Law of Mass Action, modified with activity coefficients, to determine the equilibrium constant for each binary system. The fitted values of the equilibrium constants are consistent with the trends observed in the ion exchange isotherms. The accuracy of the correlation results in the mixed solvent systems range from 1 to 10% and this is similar to the level of accuracy obtained for the ion exchange equilibria in aqueous solution. From these results it can be concluded that the Law of Mass Action is equally valid in mixed solvent systems. The variation in the equilibrium constant with mixed solvent composition, for a given binary system, correlates well with the dielectric constant of the mixed solvent. For a given value of the dielectric constant, however, the equilibrium constant, however, the equilibrium constant is dependent on the type of mixed solvent. A fundamental relationship is derived between the equilibrium constants and the Gibbs energies of transfer associated with the solvation of the ions in the mixed solvents. Based on this relationship, the redistribution of ions between the pore solution and the bulk mixed solvent, appears to be the most significant factor that governs the selectivity of the resin in mixed solvent systems.
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Bicknell, C. R. "The role of rhodium in the Andrussow process." Thesis, Nottingham Trent University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389767.

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Burnett, Hannelene Jo-Anne. "Equilibrium shift of gold adsorption in a batch reactor." Thesis, Cape Technikon, 2001. http://hdl.handle.net/20.500.11838/881.

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Thesis (MTech(Chemical engineering))--Cape Technikon, Cape Town, 2001
Over the years the carbon-in-pulp technology has been refined to become the highly efficient process that is used in our present-day system of recovering dissolved gold from cyanide leached pulps. The efficiency of a CIP circuit mainly depends on the effectiveness ofthe adsorption section as it not only determines the amount of soluble gold lost in the residues, but also indirectly affects the function of the other processes in the plant. Research in this area has declined over the past few years as a result of a decrease in the gold price. It is now more than ever important to investigate the operating conditions ofthe adsorption process to ensure that a highly effective system is maintained.The adsorption of gold cyanide onto activated carbon is to a large extent dependent on maintaining operating conditions well above those of equilibrium. The Freundlich and the Langmuir isotherms have been used by many researchers to describe the equilibrium conditions of the adsorption process. The general practice in the carbonin- pulp technology is to use an isotherm for the prediction of a circuit's performance. As confidence has increased in the reliability of these predictions, it has become important to acquire knowledge of the equilibrium condition that is driving the process. Previous research findings have indicated that the equilibrium isotherm of gold cyanide adsorption onto activated carbon is influenced by changes in the adsorption conditions down the adsorption train. This equilibrium or isotherm shift may lead to errors in the prediction of gold adsorption rates, which results in the filct that the simulations of the performance of the CIP circuits are not reliable. In this study the aim was to investigate the combined influence of various operating conditions on the adsorption equilibrium
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Van, den Berg Rudolf. "Inhibition of the pregrobbing phenomenon in gold ores." Thesis, Cape Technikon, 2000. http://hdl.handle.net/20.500.11838/907.

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Thesis (MTech (Chemical Engineering))--Cape Technikon, Cape Town, 2000
In a typical gold-recovery plant, it is estimated that a substantial amount of the gold in residues may be in the form that is recoverable by cyanidation. The gold in residues can be ascribed broadly to (l) the presence of cyanicides, which consume the cyanide radical and thus inhibit dissolution of gold, (2) refractory gold resulting from coatings on some gold particles, (3) large gold particles incompletely dissolved due to inadequate contact time, (4) unliberated gold as a result of too coarse a milled product, and (5) gold dissolved during leaching, then adsorbed by other minerals or by carbonaceous matter in the pulp. This study focuses on the latter, where dissolved gold is pregrobbed during leaching by adsorbent materials in the ore. The term pregrobbing refers to the active adsorption ofgold from cyanide pregnant solutions by components ofthe ore. It has been suggested that gold already dissolved by cyanide may be adsorbed by other minerals and by carbonaceous matter in the pulp. The presence ofcarbonaceous matter in gold ores presents a two-fold problem namely, the poor release of gold from the carbonaceous matrix and the uptake of dissolved gold by the carbonaceous leach residues. Studies by several other investigators using ores from various parts of the world have similarly shown that the natural carbonaceous matter associated with refractory gold ores often behaves like activated carbon when in contact with aurocyanide solutions. Some debate also exists over the extent to which gold may be adsorbed onto the surfaces of minerals. Different authors have identified that minerals such as' pyrite, copper sulphides, quartz and layered silicates, such as kaolin, phlogopite and ilIite exhibit gold adsorbing properties. Activated carbon was first used as a model pregrobber in batch kinetic adsorption experiments in the presence of a gold selective strong base anion-exchange resin.
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Dippenaar, Francois. "The interaction between free cyanide and silver impregnated activated carbon in a column configuration." Thesis, Cape Technikon, 2000. http://hdl.handle.net/20.500.11838/883.

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Thesis (MTech (Chemical Engineering))--Cape Technikon, Cape Town, 2000
Due to equilibrium constraints and the relatively slow kinetics of the cyanidation of gold ores, calcium or potassium cyanide is added to the leaching stage in excess to that required theoretically. This, in many situations, result in large concentrations of free cyanide present in the effluent streams from gold plants. In view of the toxicity of cyanide and the fact that cyanide is fatal in small dosages, authorities have been forced to tigl1ten up plant discharge regulations. Therefore, it is vital to remove cyanide from industrial effluent, not only to meet standard requirements, but also to recover the cyanide as a means of reducing chemical costs. The aim of this study is to recover, rather than destroy, free cyanide from effluent streams via a metal impregnated carbon-in-column configuration. The first part of the study focused on the mechanism of free cyanide recovery by metal impregnated carbon and the factors influencing the kinetics of the process in a batch reactor. The second part concentrates on the optimisation of such a process m a column configuration, and subsequently to recover the cyanide from the carbon. In the batch experiments it was found that impregnated metal carbon outperformed virgin carbon for free cyanide removal both from a kinetic and equilibrium point of view. Furthermore: the presence of other metal cyanides in solution with free cyanide has a negligible effect on the performance of the metal (silver) impregnated activated carbon to remove free cyanide. Moreover, scanning electron micrographs revealed distinct differences in appearance of metal impregnated carbons, which ultimately responds differently to the removal of free cyanide. Although the kinetics of adsorption in the column experiments was found to be slower when compared to that experienced in a batch reactor, preliminary results show that a column configuration could be suitable for a free cyanide recovery on a large scale. Furthemore, a sensitivity analysis using the kinetics of adsorption and equilibrium cyanide loading as criteria, has been conducted on the column configuration. In these studies the effects of different bed volumes, competitive adsorption with other species present, different flow rates, different column diameters and initial cyanide concentrations on the process have been evaluated. These results were plotted as break-through curves, and the mass transfer zone (MTZ) was determined. It was found that impregnation in an air atmosphere yields a product with a higher capacity than in a nitrogen atmosphere, compromising carbon through combustion. Under a nitrogen atmosphere a more robust product is formed. As can be expected, lower linear velocities and/or larger bed volumes as well as lower initial free cyanide concentrations improve the fraction of cyanide removed in a column configuration.
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Van, Wyk Andries Pieter. "Flowsheet development and comparison for the recovery of precious metals from cyanide leach solutions." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86302.

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Thesis (MEng)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: The Platreef ore deposit, situated in the Bushveld Igneous Complex, is one of the world’s largest platinum group metal (PGM) resources. The mineralogy of this resource is, however, unique as it consists of complex PGM mineralization with mainly copper and nickel, at very low PGM grades. The PGMs are mainly present in the ore as slow floating refractory minerals resulting in marginal process economics when processing via traditional mill-float-smelt processes. A new process is currently being investigated to extract PGMs from low grade Platreef ore and concentrate using a sequential heap leach process entailing heap bioleaching and high temperature cyanide leaching. The heap bioleach extracts the base metals in an acidic sulphate medium using a mixed culture of mesophiles and thermophiles. After heap bioleaching, the heap will be reclaimed, rinsed and restacked for high temperature cyanide leaching where the cyanide liquor is directly heated via solar energy in panels. Platinum, palladium and gold are extracted during the cyanide leaching stage and then recovered from the pregnant liquor either by adsorption onto activated carbon or ion exchange resins. Final metal recovery will proceed by techniques such as electrowinning and precipitation. In this thesis, process options for the recovery of platinum group metals from cyanide solutions were identified with different flowsheet alternatives developed utilizing these options. Simulations were made for the different processing alternatives with the objective of finding the alternative flowsheet to maximise net present value. The various processing options were simulated, combining data from concurrent experimental studies and data reported in literature with kinetic adsorption models. This was combined with economic models to arrive at an optimum design for each flowsheet alternative. Seven different processing alternatives for the recovery of platinum group metals from cyanide solutions were developed and investigated. These included two different activated carbon flowsheets as well as five different ion exchange resin flowsheets. The flowsheets differ in the elution procedures as well as the use of single or multiple resins. The well-known Merrill Crowe precipitation process was investigated but was found to yield unsatisfactory results. In each alternative, the cyanide solution is sent to a SART (sulphidization, acidification, recycling and thickening) plant to remove copper, nickel and zinc from solution prior to upgrading by means of adsorption onto activated carbon or ion exchange resins and subsequent elution. The platinum group metals are recovered from the eluate by precipitation using an autoclave, producing a solid product consisting of base and precious metals, while gold is recovered by electrowinning. It was found that the overall performance of the resin-in-solution (RIS) flowsheets were superior to that of the carbon-in-solution (CIS) flowsheets, from an overall PGM recovery perspective and product grades. The superior adsorption kinetics and high selectivity of the resins for the PGMs resulted in excellent overall plant performances, with PGM extractions in excess of 97%. Gold extraction efficiencies with resins were found to be lower than those achieved in the CIS flowsheets, mainly due to the higher selectivity of the resins for the divalent platinum and palladium cyanide complexes and poor gold elution efficiencies. The gold concentrations in the feed streams to these processes were, however, very low, at only 8.5% of the total precious metal content. The overall precious metal recoveries of the RIS flowsheets were thus higher than the CIS flowsheets due to the superior PGM extractions. From the cost analyses performed it was found that the RIS flowsheets requires lower initial capital costs, almost 28% lower than that require for the CIS flowsheets, while the operating cost requirements were found to be ±10% lower. This, combined with the high overall precious metal extractions, resulted in the RIS flowsheets to achieve higher net present values than those of the CIS flowsheets over an assumed project life of 15 years. The optimum flowsheet proposed for the recovery of precious metals from cyanide leach solutions was a RIS flowsheet option that employed the Amberlite PWA 5 resin, capable of extracting platinum, palladium and gold from solution, with elution being performed with a zinc cyanide solution. This process option had the lowest capital and operating cost requirements while achieving similar overall precious metal recoveries as the other flowsheets. Economic analysis of this process yielded the highest net present value, with a 31% increase in the overall return on investment compared to the optimal CIS flowsheet. Based on this, it was concluded that resin technology would be the best process option for recovering precious metals from cyanide leach solutions, however, additional research is required as the current level of process development is only at a concept phase.
AFRIKAANSE OPSOMMING: Die Platrif-erts, geleë in die Bosveld Kompleks, is een van die wêreld se grootste platinum groep metaal (PGM) reserwes. Die mineralogie van hierdie reserwe is uniek en bestaan uit komplekse PGM mineralisasie met hoofsaaklik koper en nikkel, teen baie lae PGM inhoud. Die PGMe is hoofsaaklik teenwoordig in die erts as stadig drywende minerale en dit lei tot marginale ekonomiese uitsigte wanneer hierdie reserwe deur tradisionele metodes verwerk word. Tans word ʼn nuwe proses ondersoek om die PGMe vanuit lae graad Platrif-erts en konsentraat te ontgin deur gebruik te maak van ʼn sekwensiële hooploogproses wat uit ʼn bio-loog en hoë temperatuur sianied loog stappe bestaan. Die bio-loog stap is verantwoordelik vir die ontginning van die basis metale deur gebruik te maak van ʼn suur sulfaat medium bestaande uit ʼn gemengde kultuur van mesofiele en termofiele. Nadat die bio-hooploog stap voltooi is, word die hoop herwin, gewas en herpak vir die daaropvolgende hoë temperatuur sianied loog, waar die sianied oplossing direk verhit word deur die gebruik van son panele. Platinum, palladium en goud word tydens hierdie stap ontgin en kan dan herwin word vanuit die loog oplossing deur gebruik te maak van adsorpsie deur geaktiveerde koolstof of ioon-uitruilings harse. Finale metaal herwinning kan deur elektroplatering en presipitasie vermag word. In hierdie tesis word verskeie proses opsies vir die ontginning en herwinning van PGMe vanuit sianied loog oplossings ondersoek waarna verskeie proses vloei diagram alternatiewe ontwikkel is met die doel om die opsie te vind wat die hoogste netto ekonomiese waarde sal oplewer. Die verskillende opsies is gesimuleer deur gebruik te maak van eksperimentele data gepubliseer in die literatuur en dit te kombineer met kinetiese adsorpsie modelle. Dit was dan gekombineer met ekonomiese modelle om ʼn optimum ontwerp van elke proses te verkry. Sewe verskillende proses vloei diagramme vir die herwinning en ontginning van PGMe vanuit sianied loog oplossings is ontwikkel en ondersoek. Hierdie het twee verkillende geaktiveerde koolstof prosesse en vyf verskillende ioon-uitruilings hars prosesse beslaan. Die opsies het verskil van eluerings metodes en adsorpsie medium. Die alombekende Merrill Crowe presipitasie proses is ook ondersoek, maar daar is gevind dat hierdie proses oneffektiewe resultate oplewer met betrekking tot die herwinning van die drie edel metale. In elke alternatief word die sianied oplossing in ʼn SART proses verwerk, waar die basis metale herwin word, gevolg deur die opgradering van die edel metale d.m.v. geaktiveerde koolstof adsorpsie of ekstraksie m.b.v. ioon-uitruilings harse, gevolg deur eluering. Die PGMe word dan herwin vanuit die eluerings oplossing deur termiese degradering van die metaal sianied komplekse, wat ʼn hoë graad presipitaat lewer bestaande uit die basis en edel metale. Goud word herwin d.m.v. elektroplatering. Daar is bevind dat die algehele verrigting van die ioon-uitruilings hars opsies beter was as die van die geaktiveerde koolstof opsies, beide van ʼn algehele edel metaal herwinnings en produk suiwerheid perspektief. Die verhoogde adsorpsie kinetika en hoër PGM selektiwiteit van die harse het daartoe gelei dat uitstekende algehele PGM herwinning verkry is in hierdie opsies, meer as 97%. Goud ekstraksie deur die harse was laer as wat verkry was deur die geaktiveerde koolstof opsies, weens die hoër selektiwiteit van die harse vir die divalente platinum en palladium sianied komplekse en laer hars eluering effektiwiteit. Die goud konsentrasies in die voer strome na die prosesse was laag, en het sowat 8.5% van die totale edel metale uitgemaak, wat bygedra het tot die lae goud herwinning. Algeheel was die edel metaal herwinning van die hars prosesse beter as die van die koolstof prosesse a.g.v. die hoër PGM adsorpsie. Koste evaluerings van die verskillende vloeidiagramme het getoon dat die hars opsies laer kapitaal kostes benodig, omtrent 28% minder as die koolstof opsies, terwyl bedryfskostes omtrent 10% minder was. Dit het bygedra tot die feit dat die ioon-uitruiling hars opsies ʼn hoër algehele netto ekonomiese waarde oor ʼn projek leeftyd van 15 jaar sal hê, aangesien de PGM ekstraksie, en dus die jaarlikse inkomste, ook hoër was. Die algehele proses vloei diagram wat voorgestel is vir die herwinning van edel metale vanuit sianied loog oplossings is die hars opsie wat gebruik maak van die Amberlite PWA 5 hars, wat in staat is om platinum, palladium en goud terselfdertyd te absorbeer, gevolg deur die eluering van die hars deur die gebruik van ʼn sink sianied oplossing. Hierdie proses het die laagste kapitaal en bedryfskostes getoon terwyl algehele PGM herwinning om en by dieselfde was as al die ander opsies. Hierdie proses sal verder ʼn 31% verhoging in die opbrengs op belegging lewer in vergelyking met die optimum geaktiveerde koolstof opsie. Die algehele gevolgtrekking is dat hars tegnologie die beter opsie sal wees vir die herwinning van edel metale vanuit sianied loog oplossings. Addisionele navorsing is dus nodig om resultate te verbeter aangesien hierdie studie slegs op ʼn konsep fase benadering was.
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Fernando, Kapila Chemical Sciences &amp Engineering Faculty of Engineering UNSW. "The treatment of cyanidation tailings using ion exchange resin." Awarded by:University of New South Wales. Chemical Sciences & Engineering, 2007. http://handle.unsw.edu.au/1959.4/40697.

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This thesis explores the behaviour of metal cyanide complexes under oxidative acid conditions in ion exchange systems, with the objective of developing an ion exchange based process for the treatment of gold cyanidation tailings. The novel cyanide detoxification process developed from this study employs strong base ion exchange resins to extract cyanide from tailings. Variations in the stability of cyanide complexes are exploited to concentrate, recover, or destroy cyanide species loaded on the resin, through the use of an oxidative acid eluent containing H2O2 and H2SO4. This eluent removes all base metal cyanide complexes from strong base resins, while regenerating the resin. The spent eluent, containing the base metals recovered from the tailings, can be used as a source of such base metals. Copper can be recovered separately from other base metals if necessary. Low levels of precious metals present in the tailings are accumulated on the resin as the ion exchange bed is cycled between loading and elution stages. They can be recovered economically, so as to offset the cost of the tailings detoxification. Cyanide is initially concentrated as an alkaline solution, which can be detoxified within the process or recovered for recycling. This process was successfully tested at pilot scale by treating approximately 14,000 m3 of cyanide contaminated tailings solution, over 14 loading/elution cycles on a standard strong base ion exchange resin bed. This treatment reduced the total cyanide concentration of the contaminated solution from approximately 50 mg/L to an average of 1.5 mg/L. The reagent cost was approximately ADD 0.50 per m3 of treated liquor. When the resin was repeatedly loaded with mixed metal cyanide species and eluted with the oxidative acid eluent, a gradual deterioration of the ion exchange resin performance was noted. The reduction of net operating capacity of the columns due to resin deterioration was in the order of 1-3% per loading/elution cycle. The oxidation of resin catalysed by copper, the precipitation of metal hexacyanoferrates on the resin and the oxidation of Au(CN)2- to Au(CN)4- were identified as possible factors giving rise to the reduction of resin loading capacity.
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Gray, Diane Elizabeth. "A quantitative study into carbon-in-pulp adsorption operations." Thesis, Cape Technikon, 1999. http://hdl.handle.net/20.500.11838/886.

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Thesis (MTech (Chemical Engineering))--Cape Technikon, Cape Town, 1999
Carbon-in-pulp (CIP) and carbon-in-leach (CIL) remain the most effective, and widely used processes for gold recovery from cyanided pulps. The extensive use of carbon in such processes have prompted many researchers to investigate the mechanism of metal cyanide adsorption. Not only has this provided many viable theories in the understanding of the mechanism, but it has also led to an improved understanding of the effects of the various operating conditions on the CIP circuit. However, the declining gold price has made gold producers aware of the need to either further optimise existing circuits or find alternative means of operation so as to improve efficiency. It is therefore the aim of this study to investigate the factors which influence the metal extraction circuit. In this study the effects of parameters such as gold and carbon concentrations, slurry density and stirring speed on the adsorption process were investigated. It was found that the effects of gold and carbon concentrations could be determined directly, that is, a definite linear relationship exists between these two parameters and adsorption rate. However, slurry density and stirring speed (power input) have a twofold effect on the process. For this reason two distinct terms called the "blinding" and "mixing" numbers have been identified. It has been shown that all the parameters investigated influences the rate of adsorption during the constant rate adsorption period. However, only solution concentration, carbon concentration and carbon loading influence the process during the diminishing rate of adsorption. This confirmed the belief that intraparticle diffusion is the rate controlling factor during the diminishing rate period. Furthermore, the point at which constant rate adsorption is replaced by the diminishing rate of adsorption is mainly a function of solution concentration.
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Major, Jacqueline. "A solution concentration model for CIP simulation." Thesis, Cape Technikon, 2001. http://hdl.handle.net/20.500.11838/871.

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Thesis (MTech (Chemical Engineering))--Cape Technikon, Cape Town, 2001.
Carbon-in-pulp technology is used extensively in the mining industry to recover metal cyanides from solution. Also this technology has found increasing application in the gold mining sector, replacing the less efficient zinc precipitation procedure. The extensive use of carbon in such processes have prompted many researchers to investigate the mechanism of metal cyanide adsorption. Not only has this provided many viable theories in the understanding of the mechanism, but has also led to an improved understanding of the effects of the various operating conditions on the ClP circuit. Also the modelling of this process has resulted in proposed rate equations of which the famous "kn" model is the most widely used in design. This is a single rate equation that could result in significant errors and hence a dual resistance model was developed. However this model is mathematically complex. Recently in an attempt to overcome the shortcomings of previous models, empirical calculations to accurately describe adsorption kinetics were developed at the Cape Technikon. These correlations were derived using batch experimental data. In this study the focus was on modeling the adsorption process on a continuous scale using a laboratory scale cascade system. This study utilized the fact that solution concentration is the main driving force for aurocyanide adsorption onto activated carbon and that carbon loading has an indirect effect on adsorption kinetics. The metal was ultimately tested against actual plant data and provided very accurate results.
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Mekuto, Lukhanyo. "A mixed microbial community for the treatment of free cyanide and Thiocyanate containing wastewater." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2555.

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Thesis (DTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017.
Industrial wastewater management pertaining to the mining industry has become increasingly stringent, with companies being required to develop environmentally benign wastewater management practices worldwide. The industries that utilise cyanide compounds for the recovery of precious and base metals in a process known as the cyanidation process, have contributed substantially to environmental deterioration and potable water reserve contamination due to the discharge of poorly treated, or untreated, cyanide containing wastewater. Hence, a biotechnological approach was undertaken in this study to remediate free cyanide (CN-) and thiocyanate (SCN-), which are the major chemical contaminants which are normally found in cyanidation wastewaters. Furthermore, this biotechnological approach was investigated to understand the fundamental aspects of using this approach such that the information gathered can be utilized in pilot plant studies. Therefore, bioprospecting of potential CN- and SCN--degrading organisms was undertaken using two approaches; (i) culture-dependent approach and (ii) culture-independent approach. Using the culture-dependent approach, Pseudomonas aeruginosa STK 03, Exiguobacterium acetylicum and Bacillus marisflavi were isolated from an oil spill site and river sediment samples, respectively. STK 03 was evaluated for the biodegradation of CN- and SCN- under alkaline conditions. The organism had a CN- degradation efficiency of 80% and 32% from an initial concentration of 250 and 450 mg CN-/L, respectively. Additionally, the organism was able to degrade SCN-, achieving a degradation efficiency of 78% and 98% from non- and CN- spiked cultures, respectively. Furthermore, the organism was capable of heterotrophic nitrification but was unable to denitrify aerobically, with the autotrophic degradation of CN- by STK 03 being abortive.
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Books on the topic "Cyanide proces"

1

Ingles, J. State-of-the-art of processes for the treatment of gold mill effluents. Ottawa, Ont: Environment Canada, 1985.

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Robert, Dugoni, ed. The cyanide canary. New York: Free Press, 2004.

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Lougheed, A. L. The cyanide process and gold extraction in Australasia, 1888-1913. [Brisbane]: University of Queensland, Dept. of Economics, 1985.

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Schafer, W. M. Land application of cyanide-containing mining process solutions. Bozeman, MT: Montana State University, Reclamation Research Unit, 1990.

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Knorre, H. Cyanide detoxification with hydrogen peroxide using the Degussa process. Fort Collins, CO: Colorado State University, Geotechnical Engineering Program, 1985.

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Marins, Rozane Valente. Determinação potenciométrica de cianetos em efluentes de mineração. Rio de Janeiro, RJ, Brasil: MCT, CNPq, CETEM, 1996.

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Marins, Rozane Valente. Determinação potenciométrica de cianetos em efluentes de mineração. Rio de Janeiro, RJ, Brasil: MCT, CNPq, CETEM, 1996.

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Habashi, Fathi. Principles of Extractive Metallurgy, Volume 4- Amalgam and Electrometallurgy. 800 rue Alain #504, Sainte Foy, Québec City, Canada G1X 4E7: Métallurgie Extractive Québec, 1998.

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Sheya, S. A. N. Effect of metal impurities on the adsorption of gold by activated carbon in cyanide solutions. Washington, D.C: U.S. Dept. of the Interior, Bureau of Mines, 1989.

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Sheya, S. A. N. Effect of metal impurities on the adsorption of gold by activated carbon in cyanide solutions. Washington, DC: Dept. of the Interior, 1989.

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Book chapters on the topic "Cyanide proces"

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de Jong, I., and H. T. Lieuw. "The Removal of Cyanide with Silver Impregnated Activated Carbon." In Precision Process Technology, 305–14. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1759-3_23.

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Parga, José R., Jesús L. Valenzuela, and J. A. Díaz. "Cyanide and Copper Recovery from Barren Solution of the Merrill Crowe Process." In REWAS 2013, 286–94. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118679401.ch30.

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Parga, José R., Jesús L. Valenzuela, and J. A. Díaz. "Cyanide and Copper Recovery from Barren Solution of the Merrill Crowe Process." In REWAS 2013, 287–94. Cham: Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-48763-2_30.

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Deligeorgiev, Todor G. "Molecular Probes Based on Cyanine Dyes for Nucleic Acid Research." In Near-Infrared Dyes for High Technology Applications, 125–39. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5102-3_6.

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Parga, Jose R., Jesus L. Valenzuela, and Luciano E. Ramirez. "Removal of Copper Cyanide Complexes from Solutions Formed in Silver/Gold-Cyanidation Recovery Process." In EPD Congress 2012, 263–70. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118359341.ch31.

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Patsenker, Leonid D., Anatoliy L. Tatarets, and Ewald A. Terpetschnig. "Long-Wavelength Probes and Labels Based on Cyanines and Squaraines." In Springer Series on Fluorescence, 65–104. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-04702-2_3.

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Hitoshi, Hori, Nakagawa Yoshinori, Ojima Hiroshi, Niijima Takehiro, and Terada Hiroshi. "Biologically Active Cyanine Dyes as Probes for the Identification of Active Oxygen Species." In Oxygen Transport to Tissue XIV, 255–60. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4615-3428-0_27.

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Kocheshev, Igor A., Vladyslava B. Kovalska, and Sergiy M. Yarmoluk. "Spectral properties of novel cyanine homodimere dyes as possible fluorescent probes for nucleic acids detection." In Spectroscopy of Biological Molecules: New Directions, 623–24. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-011-4479-7_281.

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Wlodkowic, Donald, Joanna Skommer, and Zbigniew Darzynkiewicz. "Rapid Quantification of Cell Viability and Apoptosis in B-Cell Lymphoma Cultures Using Cyanine SYTO Probes." In Methods in Molecular Biology, 81–89. Totowa, NJ: Humana Press, 2011. http://dx.doi.org/10.1007/978-1-61779-108-6_10.

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Barclay, M., A. Tabouret, J. C. Day, I. P. Thompson, C. J. Knowles, and M. J. Bailey. "Comparison of Effective Organisms in Bioremediation Processes: Potential Use of Nucleic Acid Probes to Estimate Cyanide Degradation in Situ." In The Utilization of Bioremediation to Reduce Soil Contamination: Problems and Solutions, 21–28. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-010-0131-1_2.

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Conference papers on the topic "Cyanide proces"

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Cristea, Lidia. "THE ENVIRONMENTAL IMPACT OF GOLD EXTRACTION BY THE CYANIDE PROCESS." In SGEM2011 11th International Multidisciplinary Scientific GeoConference and EXPO. Stef92 Technology, 2011. http://dx.doi.org/10.5593/sgem2011/s22.135.

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Aiba, Akihiro, Kazumi Kawamura, and Masashi Kumagai. "Novel Cyanide Free Electroless Au Plating for the Reliable Joint Between Ni-P/Au and Sn-Ag-Cu Based Lead Free Solder." In ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems collocated with the ASME 2005 Heat Transfer Summer Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/ipack2005-73079.

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Novel cyanide free electroless Au plating with an excellent bath stability and the reliable joint with solder was developed. Although the Au plating solution was based on sulfurous acid, the solution’s stability turned out to be excellent by the effective complexing force of the novel additives. The bath stood working without any precipitations for more than 3 metal turnovers. Since the displacement reaction between Ni-P and Au took place in the mild and the uniform way by the aid of the additives involved, resulting in the uniform and the fine grain structure of the plated film, almost no pinholes on the Au plating layer and no pitting corrosion in the ground Ni-P layer could be observed. The joint strength between the BGA pad plated with this novel Ni-P/Au plating and Sn-Ag-Cu based lead free solder ball was found to be much higher than that obtained by the conventional cyanide process. The excellent joint reliability of this process was probably due to the fact that the uniform Au layer with almost no pinholes effectively suppressed the oxidation of the Ni-P surface and eventually almost no pitting corrosion was produced in the Ni-P layer without forming any fatal voids.
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Liu, Qing, Zhengsong Wang, Yu Liang, Zhiqiang Wang, Fangting Peng, and Dakuo He. "Soft Sensor Modeling and Adaptive Model Correction Strategy for Gold Cyanide Leaching Process." In 2019 Chinese Control And Decision Conference (CCDC). IEEE, 2019. http://dx.doi.org/10.1109/ccdc.2019.8832585.

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Aichayawanich, Sawanit, Chanthima Phungamngoen, Jittimon Wongsa, and Thanya Parametthanuwat. "Degradation Kinetics of Cyanide and Uric acid in Bamboo Shoot during Boiling Process." In the 2018 8th International Conference. New York, New York, USA: ACM Press, 2018. http://dx.doi.org/10.1145/3180382.3180396.

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Pisoni, Diego S., Marluza P. de Abreu, Cesar L. Petzhold, Fabiano S. Rodembusch, and Leandra F. Campo. "Synthesis of cyanine dyes: potential fluorescent probes for biological applications." In 14th Brazilian Meeting on Organic Synthesis. São Paulo: Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-14bmos-r0159-2.

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Osawa, Hitoshi, Naomi Kawamura, Tomoyuki Matsuda, Youich Arimoto, Hitoko Tokoro, Kazuhito Hashimoto, and Shin-ichi Ohkoshi. "X-Ray Induced Magnetic Phase Transition in CoW Cyanide Probed by XMCD." In X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference. AIP, 2007. http://dx.doi.org/10.1063/1.2644581.

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Watanabe, Naoya, Shunsuke Nemoto, Katsuya Kikuchi, Masahiro Aoyagi, Tomoaki Tokuhisa, Takuo Owada, and Masaru Kato. "Basic evaluation of Au micro-bumps formed by cyanide-free electroless Au plating process." In 2014 IEEE 16th Electronics Packaging Technology Conference (EPTC). IEEE, 2014. http://dx.doi.org/10.1109/eptc.2014.7028391.

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Tang, Xiaodong, Fulong Tang, Donghong Gu, and Fuxi Gan. "Optical storage performance of cyanine film prepared by spin-coating process." In Third International Conference on Thin Film Physics and Applications, edited by Shixun Zhou, Yongling Wang, Yi-Xin Chen, and Shuzheng Mao. SPIE, 1998. http://dx.doi.org/10.1117/12.300698.

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Demchenko, Alexander P., Zoya N. Volovik, Yulia L. Briks, and Alexey D. Kachkovsky. "Cyanine dyes with branched (trinuclear) polymethine chains: long-wavelength biomembrane probes." In Photonics West '95, edited by Joseph R. Lakowicz. SPIE, 1995. http://dx.doi.org/10.1117/12.208487.

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Yang, DongFang, Danfeng Yang, Sixi Zhu, Yunjie Wu, and Fengyou Wang. "A research on the vertical migration process and background value of cyanide in Jiaozhou Bay." In 2015 2nd International Conference on Machinery, Materials Engineering, Chemical Engineering and Biotechnology. Paris, France: Atlantis Press, 2016. http://dx.doi.org/10.2991/mmeceb-15.2016.83.

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Reports on the topic "Cyanide proces"

1

Norwood, D. P., and F. E. Martinez. Evaluation of a non-cyanide gold plating process for switch tubes. Office of Scientific and Technical Information (OSTI), January 1996. http://dx.doi.org/10.2172/196440.

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Frame, B. J. Characterization and Process Development of Cyanate Ester Resin and Composite. Office of Scientific and Technical Information (OSTI), March 1998. http://dx.doi.org/10.2172/657697.

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