Cyanide Leaching Chemistry of Platinum-Group Metals - CDC stacks
Previous research by the U.S. Bureau of Mines has shown that autoclave cyanide leaching of used automobile exhaust ... was the controlling step for the dissolution of elemental Pt and Rh samples, the rate of pore diffusion was rate limiting for .... ture was that fewer base metal impurities were dissolved. A series of tests...Read More
Cyanide Leaching Platinum Catalytic Converter Chemistry
Aug 30, 2017 ... Leaching rate tests were run using a rotating disk technique. This technique was applicable only with Pd and Pt, because the dissolution rate of Rh was too low to be measured with this method. In this approach, a disk of metal is implanted into the face of an inert cylinder, which is rotated at a given speed...Read More
A new technique for extraction of platinum group metals by pressure ...
Dec 19, 2017 ... Final concentrates obtained from cyanide leaching solution using zinc cementation contained 70–90% of precious metals. For spent auto-catalysts containing ≈ 1000–2000 g/t Pt + Pd + Rh, after a pre-treatment process to remove the wrapping of the catalyst carrier and to rid surface accumulated carbon...Read More
Modification and preparation of polymeric adsorbents for precious ...
Modification and preparation of polymeric adsorbents for precious-metal extraction in hydrometallurgical processes ... Both types of material were evaluated in two applications: extraction and recovery of gold cyanide from leaching liquors and recovery of Pt, Pd and Rh from leaching solutions obtained on cyanidation steps...Read More
The mechanism of gold extraction and copper precipitation from low ...
R.H. Sergent, A. Dadgar, C.C. Shin, K.J. ReidA comparison of Bromine and cyanide leaching for refractory gold concentrate. Conference: Precious and Rare Metal Technologies, Albuquerque, New Mexico, USA (6–8 April 1988). 11. H. Nguen, K.B. Quast, R. NewellThe influence of copper on CIP processing of gold ores.Read More
US5160711A - Cyanide leaching method for recovering platinum ...
A method for recovering platinum group metals from a catalyst material comprises leaching the material with a cyanide solution at a temperature greater than about 100° C. to form soluble platinum group metal-cyanide complexes in solution. Solids are removed from the resulting pregnant leach solution, and the pregnant...Read More
Leaching and recovery of platinum group metals from UG-2 ... - SAIMM
HCl/chlorine leaching gave much improved recoveries of platinum (Pt), palladium (Pd), and rhodium (Rh): Pt (96 per cent), Pd (79 per cent), Rh (28 per cent). Cyanide (ambient temperature) still did not leach PGM well (recovery less than 25 per cent). The reason for this was considered to be passivation of the metal, but the...Read More
chapter 1 introduction - Stellenbosch University
A 2 stage heap leach process to extract base and precious metals from the Platreef ore is currently being investigated ... free cyanide ion, thiocyanate, initial precious metal (Pt, Pd, Rh and Au) ion and activated ... Based on their distribution coefficients, the affinity of activated carbon for metal ions follows the selectivity...Read More
Plasma Smelting of Unconventional Ores and Mine ... - Tetronics
and initial precious metal concentrations, whilst generating an inert slag-based material as a by-product (even ... The extraction of gold from its ores by various forms of cyanide leaching has been practised by the .... Ag) and small particles of solid metals (such as Pt, Pd, Rh and other higher melting point PGM), thereby.Read More
Refractory concentrate gold leaching: Cyanide vs. bromine ...
Gold extraction, recovery and economics for two refractory concentrates were investigated using cyanide and bromine reagents. Gold extractions for cyanide leaching (24–48 hours) and bromine leaching (six hours) were the same and ranged from 94 to 96%. Gold recoveries from bromine pregnant solutions using carbon...Read More
Ronald R H Cohen – The Conversation
Aug 13, 2015 ... Ronald R H Cohen's profile on The Conversation. ... water and cyanide use and disposal, hydrocarbon pollution, cyanide-in-pulp and cyanide heap leach processes, and chemical and hydrocarbon storage. ... We have been successful in removing, inexpensively, metal oxyanions from waste streams.Read More
heap leaching of platinum group metals from a low-grade ore ... - ORBi
Apr 16, 2001 ... secondary cleaning circuit containing up to 29 g/t of platinum group metal (PGMs), 0.36 % copper and 0.74 % nickel and less ..... large amounts of unwanted elements. Table 5: PGM, BM and gangue metal extractions from cyanide heap leach. PGMs. Pt. Pd. Ru. Rh. % Extraction. 20.3. 87. 3.4. 46. BMs. Cu.Read More
Fieldnotes - Winter 1985 - The Arizona Geological Survey
over an open ore heap piled on an impervious pad. For example, gold and silver can be separated from their ores by the application of a weak solution of cyanide and lime or caustic soda. Figure I shows a typical precious-metal heap-leaching operation. This processing technique is an extremely effi- cient way of extracting...Read More
copper trade patterns - Orica
metal cyanides, and. • pH. Control strategy/parameters: • cyanide measurement variability,. • tank residence time, and. • cyanide demand. With the gold industry looking to process more complex ores, the control of cyanide addition to the gold leaching circuit has become more crucial. On-line cyanide measurement provides...Read More
Metal Leaching Tests Procedures - Mining Technology
The procedure consists of a single-pass column leach over a 24 hour period using a mine rock sample to extraction fluid (effluent) ratio of 1:1. The extraction fluid is Type II reagent .... An aliquot for cyanide analysis must be preserved with reagent grade sodium hydroxide to pH > 12. All other analyses reported in Profiles I...Read More
alumina (Al2O3) acid leaching, 7 alumina ore ... - Wiley Online Library
cyanide leaching, 38 solvent extraction, 62. Harris process lead refining, 317 heap leaching oxidized copper ores, 73 hematite process zinc calcine hydroprocessing route,. 70. Hilty equation, 247 hot metal see pig iron, 221 hydrogen cathodic overvoltage, 99 hydrogen electrode potential, 98 hydrothermal precipitation, 44.Read More
Leaching Platinum-Group Metals in a Sulfuric Acid ... - The Vespiary
rhodium by leaching with a mixture of sulfuric acid and sodium chloride to ... Cyanide pressure leaching was examined for recycling PGM from ... 24.90. NH3. 35.30. 32.60. Table II. Contents of Pt, Rh, and Pd in Different Fractions of the Catalyst. Losses. Metal Content (%). Fraction. Pt. Rh. Pd. +150 mesh. 5.8. 0.649. 0.049.Read More
Thermodynamic and kinetic of iodine−iodide leaching in gold ...
Mineral−Metal Recovery and Recycling Research Group, Mineral Processing Division,. Department of ... Abstract: The thermodynamic equilibria and kinetic aspect of gold dissolution in iodine−iodide leaching were studied with emphasis on the effects of ......  SERGENT R H, KENNETH T. Process for metal recovery and.Read More
Leaching of gold, silver and accompanying metals from circuit boards
Au-Ag noble metal wastes represent a wide range of waste types and forms, with various accompanying metallic elements. The presented leaching strategy for Au-Ag contained in circuit boards (PCBs) aims at gaining gold and silver in the metallic form. Application of the proposed ammonium thiosulphate leaching process...Read More
possible ways of refining precious group metals (pgm)
Oct 20, 2012 ... auto catalytic converters, e.g. Rose method, cyanide extraction, chlorination, segregation, melting methods, blow- ing with metal vapours ... a result of such treatment the solution or metal collector with PGM metals is obtained. Then the ... At present Pt, Pd and Rh are mostly used in the pro- duction of auto...Read More
Kinetics of natural degradation of cyanide from gold ... - MacSphere
The fact that cyanide is used to leach gold from the ore supports that theory. The large fraction of metal sulphides in solution oxidize to polysulphides and thiosulphates. Some cyanide reacting with them becomes converted to thiocyanate and as insoluble precipitates but much of it remains in metallo-cyanide complexes and...Read More
Minix for gold chloride_paper_version 3
recovery of gold from cyanide leach solutions was developed by Mintek in 1992 and is known as. MINIX™ [1, 2]. ... production of this ion exchange resin for gold recovery from cyanide leach solutions. Their products are ... The solution was prepared to contain 0.2 mmol/L of each precious metal (Pt, Pd, Rh, Ir, Ru, Au and Ag).Read More
EP2271781B1 - Green mining: process of cyanide-free bioleaching ...
Other precious metals (Pt, Pd, Ir, Ru, Rh, Os): Precious metals other than gold or silver usually occur in conjunction with base metals, such as copper and nickel, and .... The invention allows isolating the metal from particulate material that contains only low amounts of the metal without the use of hazardous cyanide leaching...Read More
Literature Review of Hydrometallurgical Recycling of Printed Circuit ...
Jul 25, 2016 ... The results indicated that the mixture of RH and LH with the radio of 1:1 had the higher extraction efficiency, compared with using RH or LH, ... The most common leaching reagents for precious metal leaching include cyanide, thiourea and thiosulfate because of the stable metal complex formed . Table 4...Read More
EXTRACTION OF GOLD AND OTHER PRECIOUS METALS FROM E
electronic waste also contains fair percentage of precious metals like Cu, Ag, Au, Pd, Rh etc. These metals can be .... recovery of base metals. The most common leaching reagents for precious metal leaching include cyanide, thiourea and thiosulfate because of the stable metal complex formed. 18 . A) Cyanide leaching.Read More
Ronald Cohen - Civil and Environmental Engineering
I was responsible for the environmental issues including water and cyanide use and disposal, hydrocarbon pollution, cyanide-in-pulp and cyanide heap leach processes, ... Ronald R.H. Cohen. 2006. “Use of microbes for cost reduction of metal removal from metals and mining industry waste streams”, Journal of Cleaner...Read More
Method for thiosulfate leaching of precious metal-containing materials
Jun 27, 2006 ... Caney, D.J.; “Thiosulfate shows leach promise—U.S. government study shows costs about the same as cyanide,” American Metal Market, vol. 102, No. .... Jacobson, R.H. et al.; “Gold Solution Mining,” Proceedings of a Symposium on Precious and Rare Metals, Albuquerque, NM, Apr. 6/8, 1988, pp. 157-174...Read More
Method 9015: Metal Cyanide Complexes in Waters and Waste - EPA
determination of additional metal cyanide complexes, such as those of palladium and platinum. However, it is the responsibility of ..... prevent the leaching of contaminants from plastic containers. Note, however, that ...... D. D. Wagman, W. H. Evans, V. B. Parker, R. H. Shumm, I. Halow, S. M. Bailey, K. L.. Churney, R. L. Nuttal...Read More
Pretreatment Process on Refractory Gold Ores with As - J-Stage
Because gold in such ores is very fine particle form wrapped with arsenic, the leach reagents are unable to reach it in cyanide leaching process. .... In some cases, this method of preoxidation can result in a poor metal recovery. .... Nitric acid is the most efficient oxidant for pyrite, arsenopyrite and nonferrous metal sulfide.Read More
Continuous leaching-ICP-MS for the study of metal speciation in ...
Continuous leaching-ICP-MS for the study of metal speciation in sediments. Master's Thesis in the 'Applied Environmental Measurement Techniques'. GEORGE NABIN BAROI. Department of Civil and Environmental Engineering. Division of Water Environment Technology. CHALMERS UNIVERSITY OF TECHNOLOGY.Read More
Ce1-xRhxO2-δ Solid Solution Formation in Combustion ...
Redox coupling of Rh3+/Rh0 with Ce4+/Ce3+ via an oxide ion vacancy is responsible for high catalytic activity of 1 atom % Rh/CeO2 compared to Rh metal, Rh2O3 and pure CeO2. .... Structure of Platinum Catalysts under CO, Hydrogen, and Oxygen; Anomalous Behavior of Pt on Ceria after Cyanide Leaching. Jeroen A.Read More
Effect of PGM Mineralogy on PLATSOL® Leachibility
The PLATSOL® leach process was developed to extract simultaneously base metals, gold and platinum group ... similar refractory minerals (Pt,Pd)S into Pt metal and Pt-Pd alloys that responded well to the PLATSOL® process. Examples ..... S, although the platinum can be substituted by various quantities of Ni, Pd, Rh, Ru.Read More
PLATSOL™ Process Provides a Viable Alternative to Smelting
are oxidisng, the gold is leaching, at minimal incremental cost, and in a non- cyanide lixiviant. PROCESS ChEMISTRY. The most important leaching reactions ... metal dissolution. Other less critical parameters that influence precious metal recovery are the particle size of the feed to the autoclave, which should be optimized...Read More
Berend Wassink | UBC Materials Engineering
Solvent extraction-electrowinning process for the recovery of copper and cyanide from copper-gold ore leach solutions. The work was funded by a number of companies. Laboratory work was carried out on the various unit operations to establish suitable conditions for the process. Lab scale continuous testing was carried...Read More