Magnetizing and roasting method of iron oxide ore

Abstract

The invention discloses a magnetizing and roasting method of an iron oxide ore. The method comprises the following steps: adding a mixed material of which the fineness is -7mm to -10mm to a sealed reaction container, wherein the material comprises the following raw materials: 94.3%-97.1% of iron oxide ore, 1.8%-3.7% of a reducing agent bituminous coal and 1%-2.2% of a catalyst Na2CO3; 1 heating a container to 500 DEG C in a temperature rise zone, reacting C and O2 to generate CO2 and CO, and forming a weak reducing atmosphere by a reaction container; 2 heating a high-temperature zone to 820-850 DEG C, rapidly reacting CO and F2O3 under catalysis of Na2CO3 to generate CO2 and Fe3O4, dissociating Na<+> from Na2CO3, and prompting Fe3O4 crystalline grains to mix and grow; and 3 maintaining the temperature of a thermal insulation zone at 780-820 DEG C, finishing subsequent reducing reaction on CO and unreduced Fe2O3 in the step 2, and mixing the Fe3O4 in the step 3 with the Fe3O4 in the step 2 to grow. According to the method disclosed by the invention, the temperature of reducing reaction is divided into three zones, namely the temperature rise zone, the high-temperature zone and the thermal insulation zone, and full reducing reduction of the Fe2O3 is achieved, so that the magnetic susceptibility of the iron oxide ore is improved; and in addition, a catalyst Na2CO3 is capable of prompting the Fe3O4 crystalline grains to mix and grow; and the magnetic susceptibility is further improved.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a magnetization roasting method of iron oxide ore. Background technique [0002] my country is a country with a large demand for iron ore. In my country's iron ore supply, the proportion of foreign imports exceeds 50%. In order to reduce costs, iron and steel enterprises are more willing to seek domestic ore. However, although my country's ore reserve resources are abundant, there are many lean ores, with an average grade of 15% to 25%. However, steel mills need a large amount of high-grade iron concentrate raw materials for smelting. With the mining and dilution of magnetic iron ore, the production cost increases year by year. In order to meet the needs of steel mills and reduce the cost of beneficiation, weakly magnetic iron oxide ore with high iron content has entered people's field of vision. However, for weak magnetic iron oxide ore, direct beneficiation ha...

AI Technical Summary

Problems solved by technology

Although the existing reduction roasting process can magnetize weakly magnetic iron oxide ore, the magnetic susceptibility is often below 60%, resulting in very high roasting cost and low recovery rate of magnetic iron.