Preparing method for direct reduced iron using low grade high phosphorus iron ore as raw materials

Abstract

Disclosed is a preparing method for direct reduced iron using low grade difficult-to-reduce high phosphorus iron ore as raw materials. The preparing method includes crushing ferric oxide iron ore to a granularity of 0-1mm so as to produce iron ore fines; mixing the iron ore fines, pulverized coals and auxiliaries sufficiently in a ratio of (80-84): (6-9) : (8-12) by mass percentage, to produce a pellet with a diameter of about 8-16mm, placing the pellet in a reduction kiln, subjecting the pellet to a reducing reaction in a reducing atmosphere at a temperature ranging from 1180 DEG C to 1350 DEG C for 3-8 hours to produce a metallized pellet, and performing crushing, magnetic separation and separation. By means of the preparing method, not only the direct reduced iron with low sulphur and phosphorus indexes can be obtained, but also various high-sulfur iron ore and low-poor-dull-phosphorus iron ore with a total Ferrum (TFe) <=40% can be used effectively, and production operating cost can be remarkably reduced.

Description

technical field [0001] The invention relates to a method for preparing direct-reduced iron by using low-grade, high-phosphorus, refractory iron ore as raw material. Background technique [0002] Direct reduction technology is a strategic emerging industry developed for the 21st century. Compared with traditional blast furnace ironmaking, it has the advantages of less investment and quick results. It is in a stage of rapid development in China. Metallized balls produced by direct reduction technology Squid or sponge iron has a single composition and few harmful elements. It is a high-quality raw material to replace high-quality scrap steel for steelmaking or casting, and is widely welcomed by the market. However, in the previous direct reduction production mode, the raw materials were mainly produced by imported lump ore and iron concentrate powder with rolled steel scale or TFe≥66%, which is under the circumstance that the price of imported iron ore remains high at present. ...

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Problems solved by technology

However, in the previous direct reduction production mode, the raw materials were mainly produced by imported lump ore and iron concentrate powder with rolled steel scale or TFe≥66%, which is under the circumstance that the price of imported iron ore remains high at present. , which undoubtedly increases the high manufacturing cost and affects the competitiveness of this technology. On the other hand, China is a country rich in low-grade iron ore resources, and low-grade iron ore resources account for 90% of the total iron ore resources. As mentioned above, using the traditional blast furnace ironmaking method, if we want to continue to ensure the blast furnace concentrate, it will inevitably bring greater beneficiation costs for iron ore powder, high energy consumption, and high pollution. At present, there is no good technology for its development and application, especially refractory iron ore, composite iron ore, and iron-containing chemical tailings, etc., and the general sulfur content is 0.8%-2.8%, and the phosphorus content is 0.8%-1.4. % of high-sulfur and high-phosphorus iron oxide ore has no good technology to effectively develop and apply it, which not only causes many resources to be idle or wasted, but also causes serious pollution to the environment and endangers the people due to long-term accumulation of slag accumulation. safety of life

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