Experimental study on zinc precipitation by potential regulation-sulfide precipitation

Potential regulation-sulfide precipitation are used to treat zinc-containing mine acid drainage with the concentration of 100mg/L deeply. When 10 % CaO is selected as a neutralizing agent to remove iron, (the amount of 10 % CaO 7.5~14 ml/L, precipitation time of iron 30 min), the removal rate of iron could reach above 80 %. Vulcanization is performed on the de-ironed solution to precipitate zinc using NaHS as the vulcanizing agent, (with the sulfide precipitation zinc pH value of 3.4, the dosing quantity of PAM flocculant of 1 mL/L, and ORP of at 6~76 mV), the removal rate of zinc ions in acid drainage can be over 96.85 %.