The effect of lead nitrate is subtler for chalcopyrite and pyrrhotite because it was less effective to retard the reaction of sulphides with cyanide and the reaction of iron with oxygen. For gold, the addition of lead nitrate has the same effect with pyrrhotite than with pyrite; inhibiting partially the formation of a sulphur layer. This was not observed for the gold in the chalcopyrite system.
Effect of lead nitrate on cyanidation of gold ores 1277 The second gold ore, with 2.7% pyrite and 3.0% arsenopyrite, requires a very short pre-leaching time (between two and six hours) and 25-50 g/t lead nitrate. Improvement of the leaching kinetics resulted in a 43% reduction of the retention time. As illustrated in Figure 14, 89% gold extraction can be reached in 30 hours while the plant
Lead Nitrate addition in CIL operations and how the dosage of Pb Lead nitrate affects gold leaching kinetic rates. The main aim for adding lead nitrate is to help in Gold dissolution in CIL plants. Should the gold solid tails be the main aim for dosing lead nitrate in the treatment of slightly compl
Abstract: Effect of lead nitrate addition on cyanidation of Havran, Ovacık, Mastra LCu (low copper) and Mastra HCu (high copper) gold ores was investigated by laboratory tests at the Ovacik Gold Mine Metallurgy Laboratory. Leach tests were performed at optimum NaCN additions and pH values while different lead nitrate additions were applied. Ovacik cyanidation plant leaching time, 24 hours for
Various leaching parameters such as particle size, cyanide concentration, pH and the application of oxygen and lead nitrate have been investigated for the recovery of gold from an ore containing pyrite and small amounts of pyrrhotite and chalcopyrite. The application of lead nitrate in combination with oxygen generated the best results. Gold
Hydrometallurgy: Leaching in Heap, Vat, CIL, CIP, Merrill–Crowe, Effect of Lead Nitrate Concentration on Gold Leaching (3 replies) Standartenfurer. 4 years ago. Standartenfurer 4 years ago. How to effectively identify overdosing of lead nitrate [Pb(NO3)2] in gold cyanidation. I'm interested in optimizing the lead nitrate addition at a standard 4000 tpd gold mill using conventional
Cyanidation of a pyrrhotite-bearing gold ore G. Deschênes1*, Gold; Cyanide; Leaching; Lead nitrate 1. INTRODUCTION Gold deposits containing sulphide minerals are common in North America. Sulphide minerals influence gold leaching kinetics and reagent consumption. The effect of sulphide minerals and their dissolved ions on the leaching rate of gold has been investigated in the presence of
The increase of lead nitrate addition to 200 g/t and 400 g/t reduced gold recovery to 90.5% and 81.2% respectively. 100 90 80 e 70 v 60 v 50 m 40 30 20 10 Ol ,-M 1 18 ppm Oq 100 ppm Pb(NO,), + 200 ppm Pb(NO,)z 400 ppm Pb(NOJ, 12 24 36 48 Time (h) Fig.3 Effect of oxygen and lead nitrate on leaching of gold from a sulphide bearing gold ore; CN- 730 ppm; pH 11.5; 80% -74 ltm 928 Technical Note
Deschenes et al., 2000, Deschenes et al., 1998, Deschenes and Wallingford (1995) tried to improve the leaching performance of gold in the presence of some sulfide minerals by using pre-leaching, injecting oxygen and adding lead nitrate. It was reported that pre-leaching successfully overcame the effect of pyrite and pyrrhotite on cyanide consumption and the gold leaching kinetics, but it had
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It was found in Part 1 of this report that lead nitrate was ineffective in decreasing copper dissolution and had no significant effect on iron sulphide minerals. that lead nitrate works on pyrite by decreasing cyanide consumption. The difference in the nature of the results may be related to the amount of pyrite, the length of the pre-leaching, and the amount of lead nitrate added.
The effects of lead nitrate on the cyanidation of synthetic gold ore containing orpiment at pH 10, were investigated. 0.3 lb. of lead nitrate per ton failed to increase extraction; the solutions still contained soluble sulphides. When the amount was increased to 1.5 lb/ton the
If lead nitrate was added to a solution with a gold electrode that had been previously passivated by sulfides, the corrosion rate typically rose from about 0.3 to 0.95 mm y-1. The addition of lead nitrate to sulfides in cyanide solution can create a synergetic effect which results in an increase in dissolution rates of gold in cyanide solutions
Modeling of gold cyanidation Master of Science (Technology) Thesis 2008 93 pages, 43 figures, 9 tables and 1 appendix Examiner: Professor Ilkka Turunen D.Sc. Arto Laari Keywords: Gold cyanidation; Leaching; Reaction kinetics; Modeling The chemistry of gold dissolution in alkaline cyanide solution has continually received attention and new rate equations expressing the gold leaching are still
the gold contained in the ﬁne-size fractions without oxidation and lead nitrate pre-treatment for an ore that is known to require such pre-treatment. Keywords: gold ore; leaching; cyanide; particle size; laboratory testing 1. Introduction More than 75% of the gold produced in the world is extracted by the cyanide leaching of gold ores.