Method and device for producing high-nickel alloy and reduced iron through coal-based coking magnetic separation

Abstract

The invention relates to the technical field of energy-saving comprehensive utilization of mineral resources, in particular to a method and device for producing high-nickel alloy and reduced iron through coal-based coking magnetic separation. The device comprises a raw material treatment flue gas waste heat utilization system, a coal-based coking reduction roasting system, a coke separation circulating grinding iron-nickel optimization separation system, a coal-based reduction roasting system, a reduced iron separation system, a high-nickel alloy concentration separation system and an ash and dust removal system. Coke is obtained through raw material treatment, coal-based coking reduction roasting and screening magnetic separation, a reduced iron product is obtained through circular grinding and iron-nickel optimization separation, coal-based reduction roasting and coking coal separation, and a high-nickel alloy product is finally left after non-magnetic heavy metal separation and low-nickel alloy separation. The method is suitable for treating laterite-nickel ore with Ni greater than 0.6% and Fe greater than 38%, coked reduced iron and nickel are optimally separated and upgraded respectively, the nickel grade of high-nickel alloy is greater than 11%, the grade of reduced iron is greater than 94%, and the nickel recovery rate is greater than 95%; and the problems of high energy consumption, difficult thermotechnical control and unstable product quality of an existing process for treating the low-grade laterite-nickel ore are solved.

Description

technical field [0001] The invention belongs to the technical field of direct reduction for energy-saving comprehensive utilization of mineral resources, and relates to a coal-based direct reduction roasting kiln and a mineral optimization method; in particular, it relates to a method and device for producing high-nickel alloy and reduced iron by magnetic separation of coal-based coking reduction roasting coke. 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 technology is mature, but nickel sulfide Mineral 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 account...

AI Technical Summary

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, due to the dilution of the reducing gas by the flue gas in the rotary kiln pre-reduction and the reduction in the shaft furnace, neither of them constitutes a sufficient reducing atmosphere required for laterite nickel ore. Problems such as high energy consumption, low production efficiency, and unstable production; 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

[0004] At present, the traditional coking process has problems such as low efficiency of thermal energy recycling, high energy consumption, and serious pollution in the coking process.

Images