Leaching kinetics of malachite in ammonium carbonate solutions. P. D. Oudenne F. A. Olson. Materials Science, Chemistry. 1983. Leaching of malachite was conducted with ammonium carbonate as lixiviant and with temperature, lixiviant concentration, and particle size as variables. Two stages of reaction were found.
The microwave-roasted material was then leached with a mixture of ammonia and ammonium carbonate solutions. The optimum leaching efficiencies of …
Leaching kinetics of low-grade copper ore containing calcium-magnesium carbonate in ammonia-ammonium sulfate solution with persulfate. Author links open overlay panel Zhi-xiong LIU a b, Zhou-lan YIN a, Hui ... Characterization and kinetic study on ammonia leaching of complex copper ore. Transactions of Nonferrous Metals …
With two-stage leaching at 50C in concentrated ammonium carbonate, the copper-plus-nickel content can be reduced to a level of less than 1 percent from an original content on the order of 10 percent. By roasting the depleted sludge with soda ash, at least 80 percent of the chromium can be recovered in water-soluble form.
For this reason, ammonium carbonate ((NH 4) 2 CO 3) was selected as ammonium salt for the leaching of the microwave-roasted material in combination with aqueous ammonia. The effect of total {ammonia + ammonium} concentration ([NH 3 + NH 4 +]), leaching temperature, and leaching time on the leaching efficiencies of copper …
4OH (64%)>NH. 4Cl (42%)>NH. 4NO. 3(40%). The highest copper extraction efficiency was obtained in the leaching process that was conducted with the solutions obtained by mixing ammonia salts in the best conditions. Accordingly, as a result of 6 h of leaching at 30 °C in the presence of 22.5% NH. 4OH and 100 g/L (NH.
This study pretreated high-calcium gold-copper tailings by ammonia leaching to extract Ca 2+ and avoid product impurities caused by leaching of heavy metals. ... Solubility of calcium carbonate in ammonium chloride aqueous solution at T = (298.15, 323.15, and 348.15. K. J. Chem. Eng. Data, ...
Optimum leaching conditions from malachite ore by ammonia/ammonium carbonate solution are found as ammonia/ammonium carbonate concentrations: 5 M NH4OH+0.3 M (NH4)2CO3; solid/liquid ratio: 1:10 g ...
The best proportion of ammonia to carbon dioxide for rapid dissolution of metallic copper is 4 moles of ammonia to 1 mole of carbon dioxide. Thus, 68 grams NH3 and 44 grams CO2 will dissolve up to 1 mole of copper. Use of still larger quantities of ammonia and carbon dioxide does not materially influence the rate of dissolving …
Alkaline leaching with highly selective ammoniacal complexing agents is an interesting alternative for the treatment of copper concentrates. This treatment is beneficial for copper recovery because it allows the formation of soluble amines complexes, with cupric tetramine ( Cu (NH 3) 4 2 +) being the most stable.In order to suppress the unit …
The dissolution of copper during the leaching of chalcopyrite in ammonia solutions is an attractive alternative to acid sulfate leaching in the treatment of ores with high consumption of acid. Despite considerable research into this complex leaching …
Obtained result showed that the most favorable conditions for the alloy dissolution can be achieved in the ammonia–ammonium carbonate system. It allows leaching copper effectively, without uncontrolled alloy degradation (as in the chloride bath) and recovering the metal at the lowest electrolysis voltage (3.5 V), highest current …
It was found that using ammonium chloride to roast ore and leaching of the calcined slag by hot water, the precipitation of copper and cobalt from the leaching solution by adjusting pH with ammonia led to a copper and cobalt recovery of 90% and 95%, respectively (Shi et al., 1997, Xiao et al., 2010). By absorbing the exhaust gas, the …
The present work dealt with selective leaching of uranium from Alloga carbonaceous shale which assays 0.136% of U associated to 0.177% Cu and 0.068% of rare earth elements, based on an environmentally friendly method, using Na2CO3/NaHCO3 solution. The carbonate leaching kinetics was studied to determine the nature of the …
The dissolution of copper and nickel in ammonium carbonate solution was studied by techniques involving electrochemical anodic dissolution and ring-disc electrodes.
For a concentration of 0.1 mol/L of ammonium in the leaching solution, zinc basic carbonate, was obtained, while for higher ammonium concentrations (0.5 and 1 mol/L), zinc ammonium carbonate was ...
Ammonium Sulphate Leaching. Ammonia medium used for leaching was prepared by adding 66 g of ammonium sulphate to 3.5 mL ammonium solution and 200 mL of distilled water. Half of the prepared ammonia solution was used to leach 40 g of the copper tailings sample. The pH during the entire leaching process was 8.3.
Improved Cupric Ammonium: Carbonate Leaching of Copper Scrap. PB204131. Alternatives were developed to the conventional ammoniacal carbonate leaching …
Copper leaching of metals from solid matrices by ammonium carbonate is well documented. However, little is known about metal extraction with biogenic ammonia, with just two studies to date implicating the role of microbially produced ammonia from a low grade Cu ore ( Wang et al., 2013 ; Hu et al., 2016 ).
The following reagents were used in studying the leaching of flue dust with an (NH4)2C03-NH40H system: reagent-grade (NH4)2C03, technical-grade NH40H (27 wt pct NH3), and 30-mesh granular Zn. A sample of flue dust was obtained from a major secondary copper smelter. Converter flue dust from this smelter is recovered by two collectors in series.
A program of bench and pilot plant testing was conducted to demonstrate the reductive leaching of ground nodules in a seawater-based ammonia–ammonium carbonate leach solution. The batch leach testing confirmed that extraction of copper, nickel, and cobalt exceeded 90%, leaving a manganese carbonate residue for …
Iron was removed from the leaching solution with the addition of ammonia. Afterward, manganese carbonate products were prepared from iron-free manganese sulfate solution by adding ammonium carbonate at a stirring duration of 60 min, a reaction temperature of 40°C, a pH of 7, and a molar ratio of ammonium carbonate to the …
The leaching of the calcine in the form of a quenched slurry in ammonia/ammonium carbonate solutions at pH ~10 and 45 °C under anaerobic and aerobic conditions sequentially dissolves alloy to iron(II), nickel(II) and cobalt(II), oxidizes iron(II), precipitates iron(III) and allows the discard of iron rich tailings after counter …
Ammonia– ammonium carbonate leaching Leaching time, ammonium hydroxide, and ammonium carbonate concentration, pH, stirring speed, solid/ liquid ratio, particle size and temperature 98 [8] A study on the oxidative ammonia– ammonium sulphate leaching of a complex (Cu–Ni–Co–Fe) matte Ammonia– ammonium sulphate – 93.8 [9] Ammonia ...
Solvent extraction of copper from the copper leach solution obtained from the ammoniacal carbonate leaching of the Sarcheshmeh copper concentrate was carried out, and the performance of CP-150, LIX984N, ... have reviewed the applications of ammonia leaching in copper industry, and reported the advantages and disadvantages of this method [6].
to 10.8. The pH was buffered at 8.8 by the ammonium carbonate. Habashi and Dugdale m have shown for chryso- colla, an oxide ore of copper of somewhat similar behavior, that variation of pH from 8.5 to 12 had little effect on copper recovery leaching with ammonium carbonate. Consequently,
Ammonia leaching primarily relies on the complexation of NH 3 with Ni 2+ and Co 2+ to generate stable ammonia complexes Ni(NH 3) 6 2+ and Co(NH 3) 6 3+ ... Cobalt recovery from mixed Co–Mn hydroxide precipitates by ammonia–ammonium carbonate leaching. Min. ENG, 23 (2010), pp. 643-651, 10.1063/1.5038312. View PDF …
Selective ammoniacal leaching of Cu, Zn and Ni from eight diverse materials. •. Preference for M (0), MO or M (OH) 2 over spinel and silicate forms. •. Optimal Cu …
Leaching of Malachite Ore in Ammonium Sulfate Solutions and Production of Copper Oxide 165 Brazilian Journal of Chemical Engineering Vol. 32, No. 01, pp. 155 - 165, J anuary - March, 2015 Han, …
As given in Fig. 1, ammonium chloride shows the lowest copper leaching rate while copper is more favourable to be leached when ammonium carbonate is used than other ammonium salts (Temperature: 18 °C, ammonia content 7.8 wt.%, solid to liquid ratio 1/5, stirring rate 600 rpm and air flow rate 50 L/h).
CuO was obtained by heating a mixture of basic copper carbonate and ammonium carbonate diluted in an ammonia solution (25 wt%). First, a complex ion of hexaaminecopper(II) ion is formed [14]. Then ...
DOI: 10.1016/S1003-6326(11)61538-0 Corpus ID: 73719281; Leaching kinetics of low-grade copper ore containing calcium-magnesium carbonate in ammonia-ammonium sulfate solution with persulfate
The results of the leaching process with ammonium carbonate are shown in Fig. 4. As seen in the figure, ammonium carbonate leaching was studied in the concentration range of 10–250 g/L at five different temperatures. The effects of (NH 4) 2 CO 3 concentration were highly noticeable, especially at high temperatures.
Leaching Experiments. The batch leaching tests of prepared slag samples (as mentioned previously) with a combination of ammonia (25 pct ammonia solution) and ammonium carbonate were performed in a 2 L glass reactor fitted with a mechanical stirrer, a thermometer, a reflux condenser, and a gas sparger.
to recover copper due to high solubility in ammonia, later on ammonia leaching of sulfide ores was also considered. The common method was the use of oxide roasting at high
Ammonium carbonate leaching method is a new selective vanadium leaching method. Studying the leaching kinetics of vanadium in ammonium carbonate solution will promote the industrial application of this method. In this work, using different leaching conditions, the variations of vanadium leaching efficiency with leaching time …
In summary, it was possible to develop a novel process for the electrochemical deposition of copper from an ammoniacal copper catholyte using …
The leaching of oxide copper ore containing malachite, which is the unique copper mineral in the ore, by aqueous ammonia solution has been studied. The effect of leaching time, ammonium hydroxide, and ammonium carbonate concentration, pH, [NH 3]/[NH 4 +] ratio, stirring speed, solid/liquid ratio, particle size, and temperature were …
By using air as the oxidant and ammonia–ammonium carbonate leaching solution, copper could be extracted with high recovery – more than 90%, and high extraction selectivity – around 98%. In order to understand the copper extraction process and the reaction mechanisms, the effects of a range of parameters during copper …
Bingöl D, Canbazoğlu M, Aydoğan S (2005) Dissolution kinetics and a selective leaching process was obtained. of malachite in ammonia/ammonium carbonate leaching. 4. The highest copper extraction was obtained in the Hydrometallurgy 76:55–62 leaching processes that were conducted with mixtures of 9.