Hebei Messi Biology Co., Ltd. stated that magnesium sulfate heptahydrate was prepared by using salt lake magnesium chloride and sulfuric acid, and magnesium sulfate heptahydrate was dehydrated to obtain anhydrous magnesium sulfate. Using natural gas to reduce and pyrolyze anhydrous magnesium sulfate to obtain high-purity magnesium oxide. The effects of reduction pyrolysis temperature, pyrolysis time, magnesium sulfate particle size and natural gas gas flow rate on magnesium sulfate conversion rate were investigated through single-factor experiments, and the conditions for reduction pyrolysis were optimized through orthogonal experiments. The reduction pyrolysis products were analyzed and characterized by X-ray diffraction and scanning electron microscopy. The optimum preparation conditions of magnesium oxide are: pyrolysis temperature is 1000℃, pyrolysis time is 30min, particle size of magnesium sulfate is 75μm, natural gas flow rate is 25mL·min.
1. In the presence of a catalyst, magnesium sulfate is used to reduce and prepare high-purity magnesium oxide with a carbonaceous reducing agent
2. Hydrochloric acid cycle method for co-production of barium sulfate and magnesium oxide
The hydrochloric acid cycle method that co-produces barium sulfate and magnesium oxide is a method for preparing chemical substances. It mainly uses magnesium sulfate and barite ore as raw materials. It achieves the treatment of medical barium sulfate at a lower cost than industrial barium sulfate, overcoming the problem of sulfuric acid in one fell swoop. Barium has the disadvantages of high sulfur content, low whiteness, and inability to be used in medicine. At the same time, it solves the problem of hydrochloric acid outlet of thermal decomposition of magnesium chloride and serious pollution of barium slag, etc.
3. Preparation of activated magnesium oxide using magnesium sulfate waste liquid
Under mechanical stirring conditions, add lime milk with a concentration of 15%-25% to the magnesium sulfate waste liquid, adjust the pH value to 12-13, stir and react for a period of time to obtain a mixed precipitate of magnesium sulfate and magnesium hydroxide, and then add As soon as the precipitate is put into the micro-pressure reaction kettle, the pressure is controlled at 2kg-6kg, carbon dioxide is passed through it under stirring conditions, and the carbonization time is 1-3 hours. After filtration, a magnesium bicarbonate solution is obtained, and the bicarbonate solution is obtained under heating and stirring conditions. The magnesium solution is pyrolyzed to obtain basic magnesium carbonate precipitate. The pyrolysis time is 1-2 hours. Finally, it is filtered, washed, dried, and calcined at 950℃-1000℃ for 4-6 hours to obtain active magnesium oxide. This method has the advantages of simple process, high production efficiency, high magnesium yield, low cost, and environmental friendliness. It can achieve reasonable utilization of magnesium sulfate waste liquid and at the same time provide a new method for magnesium sulfate treatment.
4. Magnesium sulfate heptahydrate produces magnesium carbonate and magnesium oxide
Due to the development of boron magnesium ore, a large amount of magnesium sulfate heptahydrate is also produced as a by-product during the production of boric acid, so the development and utilization of magnesium salts is necessary. The reaction between magnesium sulfate heptahydrate and ammonium bicarbonate produces basic magnesium carbonate, which is then calcined to produce light magnesium oxide. Light magnesium oxide is widely used in industries such as rubber, plastics, medicine, food, and electronic ceramics. Therefore, the production of light magnesium oxide from magnesium sulfate has certain value.
