Whole-grade powdery iron ore magnetizing and roasting process based on three tandem rotary kilns

Abstract

The invention relates to the technical field of metallurgy and mineral engineering, and discloses a whole-grade powdery iron ore magnetizing and roasting process based on three tandem rotary kilns. The whole-grade powdery iron ore magnetizing and roasting process comprises the following steps: grading iron ore granularities, screening powdery iron ores to obtain iron ores with the granularities of 0-1 mm, 1-5 mm and 5-15 mm, initially magnetizing and roasting the iron ores with the granularity of 5-15 mm, magnetizing and roasting the iron ores with the granularities of 1-5 mm and 5-15 mm after mixing, magnetizing and roasting the whole-grade iron ores after mixing, cooling reduced and roasted iron ores, and grinding and magnetically separating after decreasing the temperature of a magnetized and roasted iron ore mixed material to be not greater than 200 DEG C so as to obtain fine iron powder with the grade of 56-60% and the metal recovery rate of 85-90%. By means of the whole-grade powdery iron ore magnetizing and roasting process disclosed by the invention, magnetization without ring formation of the powdery iron ores in three continuous reduction rotary kilns without open fire is realized; various grades of iron ores are reduced sufficiently; the roasting quality is uniform; and the phenomenon that large granular iron ores are underburnt and small granular iron ores are overburnt can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of metallurgy and mineral engineering, in particular to a full-grain magnetization roasting process of three rotary kilns connected in series for powdery iron ore capable of grading iron ore and fully magnetizing roasting and reducing it. Background technique [0002] At present, with the continuous mining of high-grade iron ore in China, it has been exhausted, and the price of iron ore has continued to rise, so that low-grade iron ore and composite symbiotic iron ore have greater mining value and become an important resource for future utilization. direction. [0003] During the mining process of refractory low-grade iron ore, generally 45-50% of powdered iron ore with particle size below 15mm will be produced. At present, the utilization methods of powdery low-grade iron ore mainly include magnetic separation, magnetization roasting and direct reduction. For refractory iron ore with a grade of 25-35% tha...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a powdery iron ore with three rotary kilns connected in series and full-grain magnetization roasting process to solve the problem of particle size in the magnetic roasting of refractory low-grade iron ore with a particle size of 0-15mm. Large differences, uneven roasting quality, kiln body prone to ringing and low recovery rate of iron ore metal

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