- 责任者：Zheng Jianhua ( Faculty of Material Science and Chemical Engineering ; China University of Geosciences ; Wuhan 430074 ; China ) ; Luo Hongyu
- 刊名：Journal of China University of Geosciences
- 出版年：2007
- 卷期：18(2)
- 关键词：low-grade pyrolusite ; neutral leaching ; ammonium sulfate
- 页码：p.
- 图表：5 illus., 2 tables, 7 refs.
- issnNo：ISSN1002-0705
- isbnNo：CN42-1279/P
Leaching studies of low-grade pyrolusite, containing 11.84% Mn with high silicon, were carried out using sodium sulfite as a reductant in ammonium sulfate medium. Various process parameters including temperature, leaching time, solid-liquid ratio, quantity of ammonium sulfate, as well as the amount of reducing agent were studied in detail. The manganese extraction yield was the response of the process. Temperature and reagent concentration exerted the most important positive effect on the manganese extraction. The optimized conditions showed that when the amount of reducing agent was a stoichonmetric amount, over 90% manganese extraction and the lowest impurities were achieved, the amount of heavy metal impurities in the manganese leaching liquid was less than 5 mg/L, and almost no iron and aluminum were extracted in 3 mol/L ammonium sulfate concentration at 100 ℃ in 45 min.