Method for reducing calcined magnesite by using calcium carbide under normal pressure

Abstract

The invention relates to a method for reducing calcined magnesite by using calcium carbide under normal pressure, which belongs to the field of nonferrous metal metallurgy. The method is characterized in that: the calcium carbide serving as a reducing agent, silicon dioxide serving as an additive, and the calcined magnesite (MgO) serving as a raw material are reacted in the presence of a small amount of calcium fluoride serving as a catalyst so as to produce magnesium vapor. The average grain size of reactants is about 100 meshes; and the actual ratio of the calcium carbide to the silicon dioxide to the magnesium oxide is (1-1.5):(0.75-1):1, and the calcium fluoride is 7 to 10 percent based on the total weight of the reactants. Material pellets with the diameter of about 3cm are prepared under the briquetting pressure of 30 to 50MPa and fed into a reactor; a reaction system does not contact air, and the inside of the reaction system is maintained in a normal pressure state; reaction is performed at the temperature of between 1,150 and 1,250 DEG C for 6 to 8 hours; and the magnesium vapor is finally introduced into a condenser so as to form crystal magnesium by condensation. A continuous reaction can be realized by the method and the process, so that production cost is greatly lowered, and the production cycle is shortened.

Description

technical field

[0001] The invention relates to a method and a process for reducing calcined magnesite with calcium carbide at normal pressure, and in particular provides a method and process for preparing metal magnesium by reducing magnesium oxide with calcium carbide as a reducing agent under normal pressure. technical background

[0002] Magnesium is a lively metal with light weight, ductility, and good electromagnetic shielding properties. The application of magnesium is mainly concentrated in the three major fields of alloy production, die-casting production, and steelmaking desulfurization, and it is also used in rare earth alloys, metal reduction and other fields. Due to the light weight of magnesium (specific gravity 1.74), magnesium alloys have obvious advantages in specific gravity, good mechanical properties and processing properties, unique electromagnetic shielding ability and reproducibility, and are known as "green" environmental protection materials, and mag...

Images