Mineralogical Phase Transform of Salt-roasted Concentrate and Enhancement of Gold Leaching by Chlorine-hypochlorite Solution

Abstract

: In order to optimize the gold leaching process from refractory sulfide concentrate, a chlorine-hypochlorite solution with varying concentrations and temperatures were applied to salt-roasted concentrate. The concentrate consisted of pyrite, chalcopyrite, and galena, which were turned into hematite through air-roasting at 750℃. Also these concentrates were changed into hematite and nantokite (CuCl)) through salt (NaCl)-roasting at 750℃. The results of the gold leaching experiments showed that the best gold leaching parameters were obtained when the hydrochloric acid-sodium hypochlorite mix was at a ratio of 1 : 2, the added concentration was 1.0 M concentration, the pulp density was 1.0%, and the leaching was done at a 60℃ leaching temperature. The leaching rate for gold was much greater in the roasted concentrate than in the raw concentrate. The leaching rate was greater in the salt-roasted concentrate than in the plain roasted concentrate too. From XRD analysis, quartz was found in the saltroasted concentrate and in the solid residue from the chlorine-hypochlorite leaching solution at 60℃.

The Geochemical Interpretation of Phase Transform and Fe-leaching Efficiency for Pyrite by Microwave Energy and Ammonia Solution

“…금광상에서 황철석은 주 로 함금석영맥으로 산출되며 유비철석과 함께 금 을 운반하는 운반자로 알려져 있다. 따라서 금광 산에서 황철석은 금을 함유하는 지시자이고 특히 황철석은 비-가시성 금(invisible gold) 상태로 금 을 함유하고 있다 (Harris, 1990;Maddox et al, 1998;Kojonen and Johanson, 1999, Kim et al, 2013a, 2013b. 특히 부유선별에서, 금을 함유하 는 황철석을 목적광물로 선별하고 석영과 같은 맥 석광물은 제거한다.…”

“…따 라서 함금석영맥, 즉 황철석에 포함된 금은 마이 크로웨이브와 암모니아 용출을 이용하면 효과적 으로 금을 단체 분리시킬 수 있을 것으로 판단된다 (Amankwah et al, 2005;Amankwah and Ofpri-Sarpong, 2011). 그러나 석영에 포함된 금은 마이크로웨이브나 암모니아 용출로 단체분리시킬 수 없을 것으로 사료된다 (Kim et al, 2013a(Kim et al, , 2013b …”