Preparation method of oxidized pellets with coarse-grain hematite as main raw material

Abstract

The invention relates to a preparation method of oxidized pellets with coarse-grain hematite as a main raw material. The technical scheme of the invention is as follows: uniformly mixing 60-70 percent by weight of coarse-grain hematite, 20-30 percent by weight of fine-grain iron-containing raw material, 2-6 percent by weight of organic binding agent and 5-8 percent by weight of water, and carrying out pressure forming to obtain ellipsoidal green-balls; and roasting the ellipsoidal green-balls at 1150-1200 DEG C for 15-30min to obtain the oxidized pellets, wherein the coarse-grain hematite is ground hematite or pelletized return fines and has the grain diameter of being less than or equal to 6mm; the fine-grain iron-containing raw material is electric precipitation dust in the smelting process of iron ore concentrate or steel; the organic binding agent is prepared by mixing starch, inorganic sodium salt, borate and water according to a mass ratio of 1: (0.04-0.15): (0.02-0.10): (4.0-5.0); and forming equipment is a double-roll ball press machine, wherein the forming pressure is 10-30MPa. The preparation method disclosed by the invention has the advantages of strong adaptability to raw material granularity, simple process, low energy consumption, low production cost and high quality of oxidized pellets.

Description

technical field [0001] The invention belongs to the technical field of oxidized pellets, in particular to a method for preparing oxidized pellets with coarse-grained hematite as the main raw material. Background technique [0002] Oxidized pellets, as a high-quality furnace raw material, occupy a very important position in the iron and steel industry. With the continuous development of the iron and steel industry, the demand for oxidized pellets is increasing. At present, my country mainly uses magnetite as raw material to produce oxidized pellets, but with continuous mining and use, the output of magnetite has gradually been difficult to meet the needs of oxidized pellet production. And hematite, which is also used as a raw material for ironmaking, has a large reserve and output both at home and in the world, so it is of great significance to use hematite as the main raw material to prepare oxidized pellets. [0003] At present, the method of using hematite to prepare oxid...

AI Technical Summary

Problems solved by technology

For the easy-to-grind hematite with low hardness, grinding is relatively easy; but for the hard-to-grind hematite with high hardness, not only the grinding cost is high, but also the grinding equipment wears very seriously, which will cause Higher production costs and lower equipment availability

In addition, the roasting temperature required for this fine-grained hematite pelletizing roasting method is relatively high, resulting in large energy consumption in production and high production costs.