Technology and system for producing sintered magnesia from magnesium hydroxide

Abstract

The invention relates to a technology and a system for producing sintered magnesia from magnesium hydroxide. The system comprises a filter cake storage bin, a variable combined feeding unit, a quick drying device, a shaftless screw conveyor, a first bucket elevator, a suspension roasting device, a high-temperature and high-pressure pressing pelletizing system, a second bucket elevator, a shaft kiln feeding bin and a high-temperature shaft kiln. The method comprises the following steps: a magnesium hydroxide filter cake prepared from seawater or brine is fed into the magnesium hydroxide filtercake as a raw material through the variable combined feeding unit, is conveyed into the quick drying device and is quickly dried, and the dried magnesium hydroxide powder is conveyed into the suspension roasting device through the shaftless screw conveyor and is roasted to obtain high-activity magnesium oxide powder; and the high-activity magnesium oxide powder undergo circulating hot-pressing pelletizing through the high-temperature and high-pressure pressing pelletizing system, is conveyed into the high-temperature shaft kiln and is calcined to obtain the sintered magnesia product. The technology has the advantages of short process flow, low production energy consumption, small environmental pollution and low production cost; and the prepared high-purity and high-density sintered magnesia product can replace a sintered magnesia product and an electric smelting product which are obtained by calcining magnesite.

Description

technical field [0001] The invention relates to the technical field of magnesia material production, in particular to a process and system for producing sintered magnesia using magnesium hydroxide as a raw material. Background technique [0002] At present, there are two main methods of producing magnesia in the world: one is calcined or fused with natural magnesite, and the other is calcined at high temperature with magnesium hydroxide prepared from seawater or brine. Obtaining high-density, high-purity sintered magnesia products has always been the development direction of magnesia production. [0003] my country's Liaoning region has high-quality magnesite resources, and since the 1990s, it has become the main production base and export base of the global magnesia market. The long-term disordered and extensive mining has led to the decline of ore quality, waste of resources, ecological damage and serious environmental pollution. At the same time, my country is rich in s...

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Problems solved by technology

However, the long-term disordered and extensive mining has led to a decline in ore quality, waste of resources, ecological damage and serious environmental pollution.

At the same time, my country is rich in seawater and brine resources, which can produce tens of millions of tons of concentrated seawater and brine rich in magnesium every year. The magnesia product produced with magnesium hydroxide after chemical treatment of seawater and brine can easily reach a purity of 98%. Above, the bulk density can reach 3.45g / cm 3 above; but at present, the existing technology of producing magnesia with magnesium hydroxide as raw material generally has the problems of long process flow and high production cost, and there are few related domestic production enterprises

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