Method for producing high-iron low-sulfur iron ore concentrate from pyrite cinder

Abstract

The invention relates to a method for producing high-iron low-sulfur iron ore concentrate from pyrite cinder, comprising the steps of controlling a calcination temperature of pyrite to be 900-950 DEG C and an excess air ratio to be 1.15-1.25 to produce red low-sulfur cinder with Fe2O3 as a principal component in a furnace in fluid bed; then adding 2-6% of biomass with an average particle size of 0.5-2mm containing 70-90% of fixed carbon, 5-25% of volatile matter and 5-20% of ash content in the cinder for magnetizing roasting by the own temperature of the cinder so as to reduce hematite in the cinder into magnetite; and finally implementing processes of ore grinding and magnetic separation to obtain the high-iron low-sulfur iron ore concentrate with an iron grade of more than 63%, the sulfur content of lower than 0.2%, and the iron recovery rate of higher than 80%.

Description

Technical field [0001] The invention belongs to the technical field of pyrite roasting acid production and slag selection iron concentrate technology, and relates to a method for producing high-iron and low-sulfur iron concentrate by using pyrite slag. Background technique [0002] Pyrite slag is a by-product of the process of pyrite sulphuric acid production. The annual discharge of pyrite slag in my country has exceeded 12 million tons. Pyrite slag is a valuable secondary resource, but the utilization rate of pyrite slag in my country is low. In my country, most of the pyrite slag is piled up or discarded, except partly used as raw materials for ironmaking and cement clinker additives. Abandoned pyrite slag will cause a waste of resources and occupy a large amount of land, and its harmful components are extremely harmful to the environment. [0003] Because the pyrite slag is rich in iron and has a fine average particle size, it is an ideal way to use the slag as a raw material...

AI Technical Summary

Problems solved by technology

[0007] Therefore, the black type slag is easy to improve the iron grade but has high sulfur content; the red type slag can obtain iron concentrate with relatively low sulfur content, but it is not easy to improve the iron grade, and the magnetization roasting-grinding treatment method is adopted, and the process route Long-term, large investment, and high-temperature roasting process, resulting in high energy consumption and high production costs, and the roasting process using coal as fuel and reducing agent produces a large amount of CO x , NO x , SO x 、H 2 Harmful gases such as S cause secondary pollution, making it uncompetitive in terms of economic and environmental benefits.