Composite additive for vanadium-titanium magnetite reduction

Abstract

The present invention discloses one kind of reducing composite additive for V-Ti magnetite. The composite additive comprises iron powder 20-28 wt%, NaCO3 25-35 wt%, CaO 20-25 wt%, and carbon process 20-25 wt%. Using the composite additive can result in the effects of: relaxing the granularity requirement to iron concentrate, reducing the milling and pelletizing steps, raising the nucleus forming speed and growing speed of iron, reducing the content of iron silicate and raising the purity of iron powder. The present invention is suitable for in industrial production.

Description

technical field [0001] The invention relates to a composite additive for reducing vanadium-titanium magnetite. Background technique [0002] One of the raw materials of reduced iron powder for powder metallurgy is iron concentrate, which requires the grade of iron to be greater than 70%, silicon dioxide to be less than 0.25%, and a monomeric structure. Since the vanadium-titanium magnetite contains ilmenite and ilmenite spinel distributed in a network shape, the iron grade of the concentrate in the mechanical separation industry is 53% to 57%, and the existing technology cannot be directly produced for powder metallurgy. Iron powder. [0003] According to the book "Ore Dressing Test Research and Industrialization" written by Zhu Junshi published by Metallurgical Industry Press, the laboratory uses anthracite as reducing agent for vanadium-titanium magnetite with iron content of 56.87%, and 15% to 20% NaCl as additive. It is reduced in a closed crucible at 1100 degrees, and...

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Problems solved by technology

But this method has the following disadvantages: ① single NaCl catalyst, its catalytic action occurs above 900 ° C, when the reduction temperature is 1000 ° C, the iron grains are very small, and at 1100 ° C, the iron grains grow to 0.15 ~ 0.03mm , the range of action of the catalyst is narrow; ②During the reduction process, the lattice difference between FeO and Fe is relatively large, and the formation of iron crystal nuclei is relatively difficult. ③In the process of high temperature reaction, iron silicate is formed, which reduces the purity of iron powder; ④The process is longer, and the cold-consolidated pellets need to regrind and pelletize the iron concentrate, and the milling strength after reduction is relatively high. Big