Device and method for optimizing low-grade laterite-nickel ore through gas-based direct reduction magnetic separation

Abstract

The invention relates to the technical field of energy-saving comprehensive utilization of mineral resources, and particularly relates to a device and method for optimizing low-grade laterite-nickel ore through gas-based direct reduction magnetic separation. The device comprises a kiln body; a roundabout snake-shaped flue is arranged in the kiln body from top to bottom; the snake-shaped flue is divided into a roasting preheating section, a roasting heating section and a roasting reduction section from top to bottom; a preheating material pool is arranged above the roasting preheating section; the bottom of the roasting preheating section is communicated with a vertical blanking passage; the blanking passage penetrates through the roasting heating section and the roasting reduction section and is isolated from the roasting heating section and the roasting reduction section; the bottom end of the blanking passage is communicated with an air cooling pipe; and the bottom of the air cooling pipe is connected with a material output device and a grinding magnetic separation system. According to the method disclosed by the invention, a final optimized product is obtained through raw material treatment, gas-based direct reduction roasting and grinding magnetic separation optimization; and the invention solves the problems of low reduction efficiency, long reduction heating time, high heating temperature and poor heat preservation effect in the prior art.

Description

technical field [0001] The invention belongs to the technical field of energy-saving and comprehensive utilization of direct reduction of mineral resources, and relates to a gas-based direct reduction roasting kiln and a mineral optimization method; in particular, it relates to a gas-based direct reduction magnetic separation device and method for optimizing low-grade laterite nickel ore. Background technique [0002] Nickel has the characteristics of strong corrosion resistance and good heat resistance, and has been widely used in various fields such as stainless steel and special alloy steel; at present, 60% of nickel metal in the world is extracted from nickel sulfide ore, and its production process is mature, but Nickel sulfide ore resources are decreasing day by day. With the rapid development of the stainless steel industry, the demand for nickel is also increasing. The development and utilization of laterite nickel oxide ore, which accounts for 70% of the earth's nicke...

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Problems solved by technology

[0003] The traditional process for processing nickel oxide ore is pyrometallurgy of nickel-iron alloy. This process mainly deals with metamorphic peridotite with high nickel grade. According to different reduction processes, it is divided into rotary kiln pre-reduction and shaft furnace reduction-submerged thermal electric furnace-refining method. However, the rotary kiln pre-reduction and the shaft furnace reduction do not constitute the direct and sufficient reduction atmosphere required by the laterite nickel ore due to the dilution of the flue gas to the reduction gas. Both of them increase the temperature for reduction, resulting in difficult thermal control and high-temperature bonding and agglomeration. , high energy consumption, low production efficiency, unstable production and other problems; the nickel recovery rate and nickel alloy grade are not high; resulting in repeated setbacks in the industrial production and application of the gas-based shaft furnace process

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