Autoclave oxidation of refractory gold-sulfide concentrates in Russian Federation. Theory and practice of recent five years

Studying the impact of alkaline sulfide leaching parameters upon the efficiency of arsenic recovery from copper skimmings of lead production

“…The results of the researches into the influence of temperature, process duration, solids content in the pulp, particle size, and the ratio of sodium hydroxide to elemental sulfur in the alkaline sulfide reagent on the process of alkaline sulfide leaching of copper skimmings af lead production are provided. Within the studied range of varied factors, the highest indexes of arsenic extraction into solution (85.04%) were achieved under the following conditions: temperature -85 o C, duration -4 hours, solids content in the pulp -350 g/dm 3 , fraction (-0.08 mm), NaOH/S ratio = 100 g/100 g in 1 dm 3 of the solution.…”

“…In this case, hydrometallurgical processing is a relatively inexpensive and more environmentally friendly method. Leaching in water, sulfuric acid [3][4][5][6]11], an alkaline sulfide reagent [7][8][9]11], a solution of sodium hydroxide [10], hydrochloric acid [5], and nitric acid [5,11] are the most widely used methods of hydrometallurgical processing of arsenic-bearing middling products.…”

“…In comparison with sulfuric acid, an alkaline sulfide solution implies higher expenses. At the same time, alkaline sulfide leaching ensures selectivity of arsenic conversion into solution, and also reduces the process time [3].…”

“…The solids content in the pulp has been varied from 150 to 350 g/dm 3 . The results are depicted in Fig.…”

“…At that, the highest arsenic recovery into solution was achieved in experiment No. 9 (Table 1), where extraction of arsenic into solution is 85.04% under the following conditions: temperature 85 о C, duration 4 hours, solids content in the pulp 350 g/dm 3 , fraction (-0.08 mm), NaOH/S = 100 g/100 g in 1 dm 3 of solution.…”