New process for producing high-quality light burnt magnesium powder series products from magnesite

China's magnesite resources are very rich, with reserves of about 2 billion tons, ranking first in the world, of which the recoverable reserves are 1 billion tons. At present, the magnesium products produced by magnesite are mainly light burnt magnesium powder and various refractory materials, lacking high value-added magnesium products, especially with the advancement of metallurgical industry technology, the amount of refractory materials is decreasing, so magnesite The economic benefits of the production of refractory materials from mines as raw materials have generally declined. However, with the rapid development of the chemical industry and increasingly strict environmental protection standards, the use of magnesium products in the fields of plastics, rubber, printing and dyeing, paper, medicine, agriculture, environmental management and other fields has maintained steady growth. How to make full use of China's unique advantages of magnesium resources, develop and produce magnesium salt series products that can meet market demand, and transform the advantages of magnesium resources into economic advantages, which is of great practical significance for the long-term development of magnesite enterprises.

Based on market research, Tsinghua University Nuclear Energy Technology Design Institute has developed a series of new products, such as magnesium sulfate, magnesium oxide, magnesium carbonate and magnesium hydroxide, which have advanced technical routes and reasonable processes. The magnesium sulfate produced by this process has high purity, meets the quality requirements of pharmaceutical grade, and the crystal size is controlled, and different crystal products can be produced according to market conditions. Light burnt magnesium powder and magnesium oxide are the starting materials of magnesium sulfate. Due to the high purity of the raw materials, the purity of the downstream products is correspondingly improved. By using this process, pharmaceutical grade magnesium carbonate and silicon steel grade magnesium oxide can be obtained. Magnesium hydroxide products further demonstrate the flexibility of the process, in addition to the production of high-purity magnesium hydroxide products and extended to high-purity magnesium fluoride. In the equipment aspect, the drying system uses a continuous system to ensure the stability of product quality. At the same time, the entire process can adjust the production volume of each product according to market conditions, so the project has strong anti-risk ability.

We have established a production demonstration plant with an annual output of 6,000 tons by cooperating with Shandong Hengxin Magnesium Co., Ltd., a state-owned large-scale magnesium mine with strong technical strength in China. Trial production is currently underway and the market is good. The existing intention is to expand into a 20,000-ton magnesium salt production plant in cooperation with large domestic enterprises with magnesite resources, and contribute to transforming China's resource advantages into economic advantages.

    Technical indicators and application notes

The main product magnesium sulfate meets the quality requirements of pharmaceutical grades, and magnesium hydroxide meets the requirements for quality of flame retardant products. Magnesium carbonate and magnesium oxide meet the quality requirements of industrial grade products. Magnesium sulfate is mainly used in the fields of monosodium glutamate fermentation, food additives and medicines; magnesium hydroxide is mainly used for burning of plastic materials and coatings; magnesium carbonate and magnesium oxide are important additives for daily chemical products such as rubber, ceramics or electronics. The filler used in the product. Silicon carbide combined with brown corundum wear-resistant brick manufacturing process

The weight percentage of raw materials is 33%~37% of brown corundum with particle size of 1~3mm, 12%~17% of brown corundum with particle size ≤1.2mm, 20%~24% of ≤0.088% silicon carbide, and 3~5mm of granularity. Al2O3 is 7%~11%, aluminum oxide having a particle size of 0.088mm is 16%~20%, and the amount of saturated phosphoric acid aqueous solution is 6%~8% of the solid amount, and the sintering temperature is 650~700°C. Compared with the prior art, the production process has the characteristics of good high temperature resistance, good thermal shock stability, resistance to quenching and rapid heat, chemical corrosion resistance, pressure resistance and wear resistance, and thus has good popularization and use value.