Method for preparing metal magnesium by using dolomite as raw material

Abstract

The invention discloses a method for preparing metal magnesium by using dolomite as a raw material, and aims to solve the problems of low reducing efficiency, high energy consumption, long production period and serious pollution existing in the conventional method for preparing the metal magnesium. The method comprises the steps: crushing of dolomites, vacuum low-temperature light calcining and recycling of carbon dioxide, cooling and heat recovery, ball-milling of mixed materials, briquetting of mixed materials, vacuum high-temperature hot reduction, separation of magnesium blocks, and utilization of slag, wherein in the vacuum low-temperature light calcining, the crushed dolomites undergo light calcining in a continuous type vacuum calcining furnace for 1 to 3 hours at the calcining temperature of between 500 and 1,000 DEG C and under the furnace pressure of 10,000 to 60,000Pa, MgCO3 and CaCO3 in the dolomites are decomposed in sequence, the reaction expression is: CaMg(CO3)2=CaCO3+MgO+CO2(gas) and CaCO3=CaO+CO2(gas), and the mixture of carbon dioxide and magnesium oxide and calcium oxide is obtained; and the carbon dioxide which flows in the furnace and heats the dolomites is recycled.

Description

technical field The invention relates to a preparation method in the technical field of vacuum metallurgy, more specifically, it relates to a method for preparing metallic magnesium by using dolomite as a raw material. Background technique Magnesium is a light, ductile and very active metal that is widely used in the automotive industry, 3C industry, military aviation and other industries. At present, the metal magnesium smelting methods are mainly divided into two types: one is the electrolysis method; the other is the silicothermal method (Pidgeon method). Molten salt electrolysis uses magnesium chloride as the raw material, metal alloy as the cathode and anode, under the melting of magnesium chloride, direct current is applied for electrolysis, metal magnesium is deposited on the cathode, and chlorine gas is released from the anode. The disadvantage is that the anode emits chlorine gas, which seriously pollutes the environment, and the equipment investment is large and t...

AI Technical Summary

Problems solved by technology

The technical problem to be solved by the present invention is to overcome the problems of low magnesium reduction efficiency, high energy consumption, long production cycle and serious pollution in the prior art, and to provide a method for preparing metal magnesium using dolomite as raw material

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