CLOSED LOOP METHOD FOR GOLD AND SILVER EXTRACTION BY HALOGENS

摘要

A method for extracting precious metals from a polymetallic ore, comprising a) generating hypochlorites from a salt brine; b) chlorination of the ore using hypochlorites under acidic conditions; c) filtering to collect a pregnant solution and treating the pregnant solution for collection of precious metals; d) filtering to separate the precious metals and a barren brine; e) purifying the barren brine; and f) recycling halogens from the purified brine in the form of hypohalites formed by electrolysis of the purified brine, and comprising hypochlorite and hypobromite; step b) further comprising scrubbing excess halogens using calcium hydroxide; treatng the pregnant solution in step c) comprises reducing an oxydo reduction potential of the pregnant solution and using calcium hydroxide for neutralization; and step e) comprising increasing the pH of the barren brine by addition of calcium hydroxide.

主权项

1. A method for extracting precious metals from a polymetallic ore, comprising:
a) generating hypochlorites from a salt brine; b) chlorination of the ore using hypochlorites under acidic conditions; c) filtering to collect a pregnant solution and treating the pregnant solution for collection of precious metals; d) filtering to separate the precious metals and a barren brine; e) purifying the barren brine; and f) recycling halogens from the purified brine in the form of hypohalites formed by electrolysis of the purified brine, and comprising hypochlorite and hypobromite; wherein: said step b) further comprises scrubbing excess halogens using calcium hydroxide; said treating the pregnant solution in step c) comprises reducing an oxydo reduction potential of the pregnant solution and using calcium hydroxide for neutralization; and said step e) comprises increasing the pH of the barren brine by addition of calcium hydroxide.