Method for comprehensive utilization of middle and low grade ferro-sulphur ore and by-production of high-alumina slag and ferrosilicon

Abstract

The invention discloses a comprehensive utilization method of byproduct high alumina slag and ferrosilicon of middle-low grade pyrite. The method comprises the following steps: each layer of the pyrite is exploited, directly smashed and added to a fluidized bed furnace for roasting in the fluidized bed to obtain sulfur dioxide gas and cinder; the sulfur dioxide-containing gas is used for producing sulfuric acid or sulfur; component adjustment is carried out after iron ore concentrate powder is magnetically separated from the cinder, or carried out directly on the cinder, by adding metallic mineral or non-metallic mineral; then, according to the mass of monoatomic carbon which is needed to reduce the ferrosilicon oxide in the adjusted cinder into the monoatomic metal by carbothermic reduction, a reducing agent which is 1.1-3 times of the mass is added; a deoxidizing agent ferrosilicon is produced after reduction; and reducing slag is discharged and cooled to obtain the high alumina slag which is used for producing chemical alumina, extracting gallium metal or being taken as a production raw material of aluminum factories. In the method, the utilization ratio of the sulfur can be improved by 40%-50% without waste slag and waste water produced by the pyrite concentrate, thereby solving the environmental pollution problem of the existing utilization technology; and all the components coexisting with the middle-low grade pyrite are fully used.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a method for comprehensive utilization of by-product high-alumina slag and ferrosilicon in the whole layer of middle and low-grade pyrite. Background technique [0002] my country is rich in pyrite resources, accounting for 10% of the world's total reserves, ranking third, but most of them are of medium and low grades. Rich ore (≥35%) only accounts for about 4% of the total reserves, and the average geological grade is 17.68%. Pyrite is the main sulfur resource in my country, accounting for 80% of the total sulfur resources; in the total pyrite resources, single pyrite accounts for 53%, and associated pyrite accounts for 27%. [0003] Pyrite deposits in the Liupanshui Economic Zone of my country are produced in the Upper Permian coal-bearing rock series, and the upper part of the rock series is coal-bearing deposits of marine-terrestrial alternating facies; the lower part of t...

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Problems solved by technology

[0004] The main beneficiation method for producing sulfur concentrate from pyrite is flotation, followed by gravity separation, magnetic separation or flotation-magnetic combined separation; according to statistics, 15% to 30% of the pyrite in the tailings has not been selected, and the production 1 ton of sulfur fine sand requires 3 to 3.5 tons of raw ore, 10 to 15 tons of water, generally produces 2 to 2.5 tons of waste residue, and 12 tons of waste water. The sulfur content of tailings is often above 7%, and the utilization rate of sulfur resources is less than 58%. Iron ore tailings are actually high-titanium, iron-containing pyrite kaolinite clay rocks that coexist with pyrite. It can be seen that the content of kaolinite in the tailings is nearly 90%, which is an important renewable resource available for use. Utilization not only wastes a lot of precious resources, but also has no power to deal with a large amount of tailings, which has caused serious harm to the local ecological environment, industrial and agricultural production, and people's health, and caused serious pollution to the surrounding waters and other environments.

The production of sulfur concentrate from pyrite has a single product, a short industrial chain, and comprehensive utilization of resources, which not only loses the benefits of mineral resources but also causes serious pollution to the local environment. Serious; the slag used to make sulfuric acid is currently only recovered by magnetic separation and some iron has not been comprehensively utilized

[0005] Indigenous sulfur refining method has a low sulfur yield (actually only 38-40%), seriously pollutes the environment, and has poor economic and social benefits

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