Selective precious metals leaching from a chalcopyrite concentrate using chloride/hypochlorite media

Chloride metallurgy: PGM recovery and titanium dioxide production

“…Increasing the chloride addition from 0 g/L to 5 g/L as NH 4 Cl-NaCl (1:1) was reported to have a positive effect on the leaching of gold. Puvvada et al, 11 have studied the selective precious metals leaching from a chalcopyrite concentrate using chloride/hypochlorite media. Direct hypochlorite leaching yielded gold and silver recoveries of 42.7% and 45.0%, respectively.…”

A Straightforward Route to Tetrachloroauric Acid from Gold Metal and Molecular Chlorine for Nanoparticle Synthesis

“…This chemistry was applied to industrial processes as early as the 19th century to dissolve gold from gold-bearing ores [2][3][4], and although chlorination was quickly replaced by cyanidation in the gold mining industry, research into the use of halogens, in particular chlorine, bromine and iodine, has made a resurgence in recent decades due to environmental concerns associated with cyanide use [5,6]. A number of the industrial procedures for ore extraction use chlorine gas injected into the reaction chamber or alternatively water that contains dissolved chlorine gas [7], while other methods employ the reaction between sodium hypochlorite, hydrochloric acid and sodium chloride (Equation (2)) to generate chlorine gas in situ [8,9].…”

The Leaching of Gold-silver from Refractory Gold Concentrate by Chlorine-hypochlorite Solution

“…(Baghalha, 2007). 그리고 염소-차 아염소산은 gold 용출율이 빠르고 독성이 없기 때 문에 정광이나 광미(slime)로부터 Au와 Ag 용출 (Almeida and Amarante, 1995;Jeffrey et al, 2001;Baghalha, 2007;Nam et al, 2008), 황동석 정광 으로부터 Cu 용출 (Puvvada and Murthy, 2000;Ikiz et al, 2006) 혹은 황비동석(enargite)으로부터 As 용출에 사용된다 (Curreli et al, 2005;Padilla et al, 2005). 또한 이 용매제는 광재(furnace slag) 로부터 Cu 용출 (Herreros et al, 1998), 폐전자제 품으로부터 Au, Sb, Sn 등을 용출하는데 사용되었 다 (Saleh et al, 2001).…”