Ammonia leaching was first used for recovery of non-ferrous metals such as copper from oxide ores or ores containing pure copper, but gradually the use of this technology was developed from more ...
Notably, the ammonia leaching of Cu and Ni from various raw materials (from the leaching of native copper ore at Lake Superior District and Caron's process for nickel laterite ore from the early ...
AMMONIA LEACHING IN THE COPPER INDUSTRY: A REVIEW Ekmekyapar, A, Oya, R and Kunkul, A, 200 3. Dissolution kinetics of an oxidized copper ore in ammonium chloride
Ammonia leaching of sulfide copper concentrates generate buffer type liquors (pH ranges from 9 to 10), because of the excess of ammonia and significant amount of ammonia sulfate as a leaching agent. Metals such as Cu, Ni, Co and Zn occur in ...
10/12/2013 Ammonia and ammonium salts have been recognized as effective leaching agents in hydrometallurgical processes due to low toxicity and cost, easy recovery and high selective recovery of metals. New research findings on considerable advantages of leaching by these agents and elimination of problems associated with acid leaching have resulted in a new approach in the world to this method.
Copper recycle from sulfide tailings using combined leaching of ammonia solution and alkaline bacteria Article (PDF Available) in Journal of Cleaner Production 189 April 2018 with 444 Reads
TREATMENT OF A COPPER- RICH GOLD ORE BY AMMONIA ASSISTED CYANIDE LEACHING Figure 7. Effect of ammonia pretreatm ent (1 M NH 3 ) and the addition of ammonia
Copper minerals, even though minor components of precious metal ores, dissolve in these cyanide leaching solutions, consume cyanide, cause fouling of mill solutions, and thus interfere with the precipitation and recovery of gold.2,3,4 Here is a summary of
Copper–ammonia catalyzed thiosulfate leaching of silver sulfide is by substitution of cupric or cuprous for silver. • The cupric reaction is favored over cuprous reaction due to a thermodynamic barrier, even though Cu 2 S and Ag 2 S have similar structures. Copper ...
Ammoniacal leaching for dissolution of copper oxides. • The pH in leaching should be controlled between pH 9–10. • Ammonia leaching does not alter copper sulfides. • PLS precipitates with S or SO 2 to form CuS and/or Cu2S. Excess sulfur (150–200%) is more
In this diagram, the copper oxide CuO does not appear in the solution; all the copper being complexed by the EDTA and ammonia. This diagram indicates that the low efficiency of the leaching systems shown in Fig. 1 , Fig. 2 , Fig. 3 is not related to the copper oxide precipitation but to the decrease in the redox potential of the couple Cu(EDTA) 2 − /Cu(NH 3 ) 2 + , as was shown in Fig. 4 b.
Ammonia has already been established as an effective complexing agent for transition metals such as copper, nickel, cobalt, silver, and platinum. It has a number of inherent advantages as a ligand due to its low cost, low toxicity, low corrosivity, easy regeneration due to its low vapor pressure and above all good complexing ability.
Leaching of copper ores occurs by means of either acid leaching or ammonia leaching. It is known that acid leaching is not suitable for ores which contains carbonates such as covellite or limestone. In such case, ammoniac leaching is performed although it is often carried on with both high pressure and elevated temperature.
The results of silver leaching from the mineral concentrate show that extraction velocity is favored by increasing copper and thiosulfate concentrations and reducing the quantity of ammonia. At larger copper concentration leaching velocity increases, as may be seen in Fig. 1 as a function of time.
Ammonia as a modifying agent to mitigate copper interferences in cyanide leaching of gold has been knownfor over 100 years as it was discoveredby Hunt in 1901 (Adams, 2005; Muir, 2011) Ammonia is added to stabilize
The effect of reaction temperature on the leaching rate of copper from the malachite ore in ammonium sulfate solutions was examined at temperatures of 30, 40, 50, 60, and 70 C. While conducting these experiments, the values of ammonium sulfate concentration, solid to liquid ratio, particle size, and stirring speed were fixed at 4 mol/L, 2 g solid/500 mL solution, 62.4 μm, and 400 rpm ...
Thiosulfate-copper-ammonia leaching of pure gold and pressure oxidized concentrate 1081 Δ𝑓=−𝐶𝑓 Δ𝑚, (1) where Cf is the sensitivity factor for the crystal used (56.6 Hz cm 2/µg), f is the frequency (Hz) and Δm is mass change (µg). A saturated silver
Optimal Conditions for Ammonia Leaching of Copper/Chalcocite-Rimmed Pyrite: Part 2 Martin Y. Woode 1 1Department of Chemical Engineering Kwame Nkrumah University of Science Technology (KNUST) Kumasi, Ghana Mike A. Acheampong 2*2Department of Chemical Engineering
studied. The ammoniacal thiosulphate leaching of gold is dependant on both ammonia and thiosulphate concentration. The leaching is improved significantly at a particular ratio of ammonia to thiosulphate concentration and that ratio varies from ore to ore. Copper
Copper smelter slag can be considered as an important source for using in the copper hydrometallurgy. Ammonia leaching seems to be attractive for processing copper slag. Under the influence of ammonia, copper, which is part of the minerals of ...
Leaching of copper can be accomplished with ammonia solution in which metal such as copper is selectively extracted while restricting the dissolution of iron or manganese. Both metals can pose a real problem in the subsequent stages of hydrometallurgical
When aqueous ammonia is added to a solution of cupric sulphate, the blue complex formed has the formula Cu(0H)2 • 4 NH3 This is usually considered to be copper ammonium hydroxide, [Cu(NH3)4] (OH)2, where the copper and ammonium are combined forming a divalent, complex cation, [Cu(NH3)4]++ Under some conditions, this cation can be formed in cyanide solutions containing copper.
The main important parameters in ammonia leaching of copper tailings have been prioritized as solid/liquid ratio, leaching time, temperature and the concentration of ammonia. The optimum leaching conditions are found to be: 4/1 liquid/solid ratio, 4h leaching time, 40°C, 3 mol/L NH4 +.
University of Cape Town Ammonia leaching as a pre-treatment for the processing of oxidised PGM ores By Research Candidate: Kabwe Musonda Supervisors: Professor Jochen Petersen Thesis submitted in partial accomplishment of the requirements of the
Ammonia leaching of copper sulfide concentrates The first ammonia leaching plants, applied to copper carbonate and native copper tailings in 1915, were followed more recently by research and development of ....
copper leaching from an industrial sludge using ammonia solution. This present work will develop the effect of nitric acid/ammonia ratio on the leaching of rich - cobalt copper oxidised ore. It will also evaluate the effect of key parameters (time, ammoniaII.
TY - JOUR T1 - Recovery of cupric oxide from copper-containing wastewater sludge by acid leaching and ammonia purification process AU - Wu, Jun Yi AU - Chou, Wei Shan AU - Chen, Wei Sheng AU - Chang, Fang Chih AU - Shen, Yun Hwei AU - Chang
Abstract An extensive literature survey on the principles and applications of ammonia leaching processes in hydrometallurgy is presented in this paper. The combination of ammonia anal ammonium salt... XINGHUI MENG Department of Metallurgical Engineering , South Dakota School of Mines and Technology , City, SD, 57701-3995 KENNETH N. HAN Department of Metallurgical
The ammonia leaching tests were carried out to recover valuable metals from alloy obtained from smelting reduction process of mobile phone printed circuit boards. Leaching factors such as kinds of salt, ammonia concentration, and the interaction of metals, which are components of PCB, were investigated to improve the leaching efficiency.
Ammonia Leaching Flow Diagram - Kennecott Copper Corporation, On Copper River Northwestern Railroad, Kennicott, Valdez-Cordova Census Area, AK Creator(s): Anderson, Nanon Adair, creator Date Created/Published: 1985 Medium: 24 x 36 in. (D