Hebei Messi Biology Co., Ltd. stated that silicon steel grade magnesium oxide is a relatively economical magnesium oxide coating material, and it is also a high value-added magnesium oxide product. China is a major producer of magnesium compounds, ranking first in the world, but the product grade is low, the production scale is generally small, the automation control level is low, the energy consumption is high, and the research, preparation and application of high-purity, high-quality and high-value-added magnesium oxide are still far behind developed countries. It is crucial to accelerate the research and application of silicon steel grade magnesium oxide preparation, adopt advanced technology and advanced equipment, improve production level, develop high-purity magnesium series products, and transform China from a major magnesium oxide producer to a magnesium oxide producer.
In the production process of silicon steel grade magnesium oxide, due to the strict requirements on the purity, particle size, hydration rate, etc. of magnesium oxide, the ore resources are becoming less and less, and the grade is getting lower and lower, the impurity content is high, and the product quality is unstable; seawater or salt lake brine resources are very huge and cheap, with low production cost and low impurity content, which is suitable for the production of silicon steel grade magnesium oxide. The magnesium salt reserves in salt lake brine in China alone are as high as 4.816 billion tons. The lack of comprehensive utilization of a large amount of magnesium resources in salt lake brine not only causes huge waste, but also affects potash fertilizer production. Therefore, using seawater or salt lake brine as raw materials to produce high-purity silicon steel grade magnesium oxide has great advantages and will be an inevitable trend in the development of the industry.
Although the production cost is low when lime is used as a precipitant, it has high requirements for lime purity and activity. At the same time, it will introduce calcium ions that are very harmful to the quality of silicon steel, making it difficult to remove impurities, and the product quality cannot be guaranteed. There are also problems such as large slag volume and serious environmental pollution. When sodium carbonate, sodium hydroxide, etc. are used as precipitants, the production cost is very high, and impurity ions will be introduced, the energy consumption is high, and the product quality is unstable. Ammonia water, ammonium carbonate or ammonium bicarbonate are used as precipitants. Due to their wide sources, they are relatively cheap, and they will not introduce impurity ions. The product purity is high, and the recycling of ammonia water and carbon dioxide can be achieved. Therefore, in the future, it will be a development trend to use ammonia water, ammonium carbonate or ammonium bicarbonate as precipitants and use basic magnesium carbonate as an intermediate product.