Abstract: Based on the adsorption co-precipitation mechanism, the gypsum and magnesite powder were mixed to add the simulated lead polluted water (including of turbid saturated sulfate lead solution with excessive sulfate lead micro-particles, Pb²⁺ about 2 mg/L, the total lead of 10 mg/L).The effect of gypsum (CaSO₄·2H₂O) and milling magnesite (Mg (OH) ₂ and MgCO₃ mixtures) content as well as the filtering time on reducing lead content was studied.It is found that under optimal condition, the total lead content in water bodies can be reduced to 0.02 mg/L.Based on this, the light burned magnesite gypsum composite filter bed process was proposed.Some tests on trace lead leaching water from lead-zinc tailings and battery factory showed that the lead content in water was lowered to below 0.04 mg/L and the total cadmium was reduced to below 0.1 mg/L, being suitable for water supply and the treatment of mine tailing.

Key words: Gypsum light burned magnesite composite filter bed, Leaching water from lead-zinc tailings, Trace lead contained water, Non-destructive repair