Purification of zinc sulfate solutions from cobalt and nickel through activated cementation

Recycling Zinc from Metal Oxide Varistors Through Leaching and Cementation of Cobalt and Nickel

“…Parameters that are known to affect cementation reactions are pH, temperature, activator concentration, and zinc dust quantity [12,13,[17][18][19][20][21]. Van der Pas et al [17] concluded that the optimal conditions for cementation in a solution containing 30 mg/L cobalt were 30 mg/L copper and 1.5 mg/L antimony (both as activators) as well as addition of 4 g/L zinc at a solution temperature of 70°C.…”

“…Børve [20] suggested that optimal conditions for cobalt (15 mg/L) cementation arise when the solution contains 50-100 mg/L copper and 3-4 mg/L antimony (both as activators) with a solution temperature less than 80°C. Work by Boyanov et al [21] determined that maximum cobalt removal occurs at a temperature of 80-85°C, copper concentration of 200-300 mg/L, and 18 times the stoichiometric amount of zinc dust. According to their work [21], maximum removal of cobalt and nickel occurs when the Sb:Co ratio is between 0.5:1 and 2:1.…”

“…Work by Boyanov et al [21] determined that maximum cobalt removal occurs at a temperature of 80-85°C, copper concentration of 200-300 mg/L, and 18 times the stoichiometric amount of zinc dust. According to their work [21], maximum removal of cobalt and nickel occurs when the Sb:Co ratio is between 0.5:1 and 2:1. 18,20].…”

“…The aim was to investigate the feasibility of using cementation as a means for MOV leachate purification to make it suitable for zinc electrowinning. Since the MOV leaching solution contains 400 mg/L cobalt and 100 mg/L nickel, the optimal conditions from other studies [17,18,20,21] were scaled up for this investigation. Present investigations included studies of the influence of temperature, pH, activator concentration, and zinc dust surface area on the rate and extent of cobalt and nickel cementation.…”

Kinetic Aspects and Thermo chemical Analysis of Silver Cementation from Residual X Ray Fixer by Cementation on Zinc

“…The cementation processes have been constantly used and researched [3][4][5][6], some of them are batch agitated processes, other use reactors with disc rotating cylinder 4. Silver is the most studied metal using zinc as a cementing medium 3; however, researches to recover Au, Co, Cd, Cu and Ni have also been reported [3,[7][8][9][10][11][12]. It has been reported Abstract: Silver cementation with zinc from residual X ray fixers was studied.…”