Process for producing nickel iron particles by carrying out reducing calcination on laterite-nickel ore through rotary kiln one-step method

Abstract

The present invention discloses a process for producing nickel iron particles by carrying out reducing calcination on laterite-nickel ore through a rotary kiln one-step method. According to the present invention, at a material preparing and ball producing stage, the MgO/SiO2 in raw materials is more than or equal to 0.54, and the whole melting point of the material is increased by adding dolomite or magnesia and other magnesium-based supplements during insufficiency, such that the mixing pellet is in the solid state at a high temperature of 1250 DEG C at a reducing calcination stage so as not to cause the ringing of the rotary kiln, and the service life of the fireproof material of the rotary kiln is prolonged due to the decreasing of the maximum temperature of the reducing calcination stage; the FeS in the vulcanizing agent in the mixing pellet preferentially reacts with the NiO in the laterite-nickel ore to achieve the agglomeration of the reduced metal particles, such that the metal achieves the high yield.

Description

technical field [0001] The invention relates to the technical field of metallurgical technology, in particular to a process for producing ferronickel particles by reducing and roasting laterite nickel ore in a rotary kiln in one step. Background technique [0002] As a strategic element, nickel plays an extremely important role in the development of the national economy. About 2 / 3 of the world's nickel is used to produce stainless steel, and the cost of nickel raw materials accounts for about 70% of the production cost of austenitic stainless steel. In recent years, in order to reduce the production cost of stainless steel, stainless steel enterprises have begun to use a large amount of nickel-containing pig iron. [0003] At present, nickel-containing pig iron is smelted with laterite nickel ore containing 0.8-2.0% nickel as raw material. The smelting process of laterite nickel ore includes blast furnace, RKEF process, and rotary kiln direct reduction method. Among them, ...

AI Technical Summary

Problems solved by technology

The reduction of nickel and iron can be achieved through direct reduction of laterite nickel ore at a temperature of 1000-1100 ° C. However, the nickel-iron alloy particles obtained by low-temperature reduction are small and cannot migrate and aggregate into granules. It is difficult to separate slag and iron during the reduction-separation process, resulting in Tailings have high nickel content and low metal yield, only 30-40%

[0004] In order to increase the metal yield of the direct reduction method of the rotary kiln, the reduction temperature in the reduction section of the rotary kiln is usually controlled at 1300-1400°C in the modern direct reduction process of the rotary kiln. The material in this temperature range is in a semi-molten and molten state, which is beneficial to a certain extent The ferronickel particles are fully aggregated and grown to facilitate the subsequent grinding operation, increasing the metal yield to about 90%, but the molten material under high temperature conditions is easy to cause ring formation, and high temperature conditions have high requirements for refractory materials of the rotary kiln, resulting in Refractory kiln lining life shortened

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