A kind of method for reducing magnesium oxide in nickel-iron slag and method for preparing slag wool

Abstract

The invention discloses a method for reducing magnesium oxide in ferronickel slag and a method for preparing slag wool. In the process of making mineral wool from molten ferronickel slag, impregnated carbon is added during the slag discharge process of ferronickel smelting furnace, and the ferronickel slag is treated with impregnated carbon. During the transfer process, the molten nickel iron slag and the impregnated carbon are fully mixed and kept in a holding furnace to reduce the magnesium oxide content in the nickel iron slag; wherein, the preparation process of the impregnated carbon includes: fully mixing the calcium chloride aqueous solution with the carbonaceous material , and then perform solid-liquid separation and drying to obtain impregnated carbon; the amount of impregnated carbon used is determined according to the magnesium oxide content in the nickel-iron slag. The invention can reduce the magnesium oxide content in the ferronickel smelting slag, especially can reduce the magnesium oxide in the free state in the ferronickel smelting slag, is beneficial to improve the quality of slag wool, and is a great reduction in the ferronickel slag containing high magnesium oxide. And high-value utilization has created conditions, and can also realize the recovery of magnesium in nickel-iron slag.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a method for reducing magnesium oxide in nickel-iron slag and a method for preparing slag wool. Background technique [0002] Nickel-iron slag is the solid waste slag discharged in the process of smelting nickel-iron alloy from nickel ore, and it is the fourth largest industrial waste slag after steel slag, blast furnace slag and red mud. With the reduction of nickel sulfide ore resources, nickel oxide ore has gradually become an important resource for nickel extraction. The main mineral used in nickel oxide ore is laterite nickel ore. Carbon reduction, after carbon reduction, ferronickel products and smelting slag are produced. In the production of ferronickel from laterite nickel ore, about 14t of ferronickel slag is discharged for every 1t of ferronickel produced, and the amount of waste slag is large. In China, nearly 2 million tons of ferronickel slag is produced ever...

AI Technical Summary

Problems solved by technology

Due to the high content of magnesium oxide in some lateritic nickel ores, the content of magnesium oxide in ferronickel slag produced by ferronickel smelting exceeds the limit of magnesium oxide content required in the mineral wool preparation process, resulting in poor quality of the produced mineral wool. Very low cotton yield

In ferronickel slag with high magnesium oxide content, in addition to forming a relatively stable compound with silicon dioxide in the slag, magnesium oxide in the slag will also have some free magnesium oxide. The melting point of free magnesium oxide is high. During the heat preservation process, most of them exist in the state of solid particles. During the blowing process of molten slag, it is easy to break the cotton and form solid particles, resulting in a decrease in the cotton-forming rate of slag wool. Nickel-iron slag with a high content of magnesium oxide cannot be used as a raw material for mineral wool

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