Nickel is a strategically important metal with excellent chemical stability, ductility and mechanical strength. It is widely used in stainless steel smelting, new composite material preparation, hydrogen storage material preparation, medical treatment, military and many other industries and fields.
At present, the available nickel resources in the world include two types, namely nickel sulfide ore and laterite nickel ore. In the proven nickel resources and reserves, nickel sulfide ore accounts for about 30%, and laterite nickel ore accounts for about 70%. However, about 70% of nickel production comes from nickel sulfide ore. With the continuous consumption of nickel sulfide ore, there are fewer and fewer nickel sulfide ore resources available for mining at present, and the exploration period and construction period of nickel sulfide ore are relatively long. As the main raw material of nickel resources in the future, laterite nickel ore is rich in reserves. , easy to mine and convenient to transport, so the efficient development and utilization of laterite nickel ore is of great significance to actual production.
Pyrometallurgical smelting process of laterite nickel - rotary kiln drying and prereduction - electric furnace smelting
Rotary kiln drying and pre-reduction - electric furnace smelting process is currently the most widely used pyrometallurgical smelting process for laterite nickel ore in the world. The production process of the method is as follows: the laterite nickel ore is crushed and screened to a particle size range of 50-150 mm, sent to a rotary kiln for drying and pre-reduction to obtain calcine, and the calcine is mixed with a reducing agent and loaded into an electric furnace for reduction and smelting to obtain nickel-containing > 8 % crude ferronickel, and then further blowing in a converter can produce high-grade ferronickel with a nickel content of > 25%, which can be used to produce stainless steel.
Rotary kiln drying and pre-reduction - electric furnace smelting process is currently the main process for the production of nickel-iron alloys. This method has the advantages of simple equipment, short process flow and high production efficiency, but the following problems still need to be solved or optimized:
(1) The rotary kiln has serious ring formation and high maintenance cost;
(2) The energy consumption is high and the amount of slag is large, requiring sufficient fuel or electricity locally;
(3) Cobalt in laterite nickel ore cannot be recovered, and it is suitable for laterite nickel ore with a cobalt content of less than 0.05%;
(4) The content of nickel in laterite nickel ore has a great influence on the production cost of this process, and it is suitable for smelting ores with nickel content greater than 2%
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