Jinchuan Nickel Sulfide Lean Ore Mineral Composition Of The Bacterial Leaching Of Adaptive Research

Jinchuan Group Company Ltd (JNMC) is the biggest nickel producer in China, and has abundance of nickel lean ore, which is unprofitable using conventional processing route. In order to extract these resources, JNMC commenced development of new technology of bacteria leaching since 2000 and conducted 5000t scale pilot in 2002. In the processing of bacteria heap leaching met many problems, such as over-high magnesium oxide, easy to be muddy in leaching, high consumption of acid etc. After researching mineralogy characteristics of Jinchuan, Hami and other same type of nickel ore and comparing the differences in leaching processing between Jinchuan ore and Hami ore, the article conclude that:1. Jinchuan nickel lean ore isn't profitable of heap leaching at current economic technique due to it's special and complicated texture, over-high magnesium, deeply alteration, sulphide minerals over-fine granule, detail as follow:(1) Jinchuan ore, which composed mainly of serpentine, chlorite, is so deeply altered that vulnerable to be floured and muddy in the processing of crushing and leaching, resulting in leaching heap impenetrable.(2) The high magnesium and iron in the ore causes sufficient ion of magnesium and iron into solution and makes the solution saturated. The solution system rimes sulphate, hydro-oxide firstly, which brings colloid sediments around granules to film the liquor from ore, and make ore impenetrable.(3) Magnesium extract results in restrain of bacteria vigor, and so much as death of bacteria, so the leaching is influenced greatly. It also brings high consumption of acid and operating costs, and much low Ni²⁺ grade in liquor due to saturation by magnesium, which makes more difficult to process post-solution.(4) Jinchuan ore contain lower sulpher at 2.13%, whereas Hami ore contain 3.15%. Bacteria is favorable of sulpher.(5) The aggregation of metal sulphide in Jinchuan ore is so line at about 0.05-2mm,which means more crushing to be needed to make liquor surrounding the sulphide mineral. In Jinchuan pilot, the large scale crushing at -25mm is the main reason of failure.(6) Jinchuan ore contains 1-10% nickel silicate, embedding in crystal lattice of silicate.this part nickel is not extractable in common air pressure and temperature.2.Hami nickel ore is suitable for heap leaching at currently technical and economical condition, because of minor alteration, low MgO grade of 6%, high sulpher.3.Bacteria leaching is favorable for lean ore and solid wastes, but exists some problem to need more research in processing Jinchuan lean ore, such as the technology how to be used to the features of ore itself.