Magnesium Carbonate CAS 13717-00-5

A process method for producing rare earth magnesium alloy with basic magnesium carbonate, the concrete steps are:

The basic magnesium carbonate with MgO content of 41.7%wt was put into a stirring reaction kettle, and hydrochloric acid was added to carry out stirring reaction. After the solid was completely dissolved, a magnesium chloride solution was obtained, which was evaporated by heating and concentrated to a mass fraction of magnesium chloride of 40.1%. Cool to 20°C at a rate of 2°C/min to precipitate crystals, separate by suction filtration, and dry for 1.5h to obtain high-purity magnesium chloride hexahydrate crystals. The obtained high-purity magnesium chloride hexahydrate and lanthanum chloride heptahydrate are uniformly mixed according to a weight ratio of 1:0.10, as an electrolysis raw material, loaded into a graphite crucible, and a potassium chloride and sodium chloride mixture of 1:1 with a mass ratio is As the electrolyte, the liquid rare earth magnesium alloy is used as the sinking cathode, and the graphite crucible is used as the anode. The electrolytic raw materials after heating and melting are continuously added dropwise to the electrolyte. The current is 1000A, the voltage is 5V, and the temperature is 800 ℃. By direct current electrolysis, rare earth magnesium alloy is obtained at the cathode. After EDS detection, the lanthanum content of rare earth magnesium alloy is about 5%.

The method that utilizes magnesium carbonate coarse ore to prepare high-purity magnesium oxide is as follows:

1. The crude magnesium carbonate ore, the primary product of Longmucuo and Jiezechaka salt lake mixed with brine (sulfate type and carbonate type salt lake mixed with brine), is used as raw material, and the main component in the raw material component is 67.2% 4MgCO3·Mg( OH)2·5H2O, the minor components are NaCl and a small amount of sulfate and boron-containing compounds 0.27% (calculated as B) and so on. First, the coarse magnesium carbonate ore is crushed and sieved with a 60-mesh screen, and the soluble impurities are removed by traditional washing and filtration methods (for example, deionized water is used to prepare a slurry with a liquid-solid ratio of 5:1 by weight, Filter in vacuo after mechanical stirring, twice).
2. Add a sodium bicarbonate solution with a mass concentration of 9% to the magnesium carbonate coarse ore after screening and removing soluble impurities as a boron remover, wherein, according to the mass ratio, the ratio of sodium bicarbonate solution to the magnesium carbonate coarse ore is calculated. The liquid-solid ratio is 10:1, and the magnesium carbonate coarse ore is dissolved in the sodium bicarbonate solution to form the first slurry.
3. Putting the first slurry into the reactor for hydrothermal reaction to obtain the second slurry. The temperature at which the hydrothermal reaction was carried out was 180°C, and the reaction time was 10 hours.
4. The second slurry is filtered, washed and dried to obtain anhydrous magnesium carbonate.
5. The anhydrous magnesium carbonate is calcined to obtain high-purity magnesium oxide. The firing temperature was 1200°C, and the firing time was 10 hours.

After testing, the purity of the prepared magnesium oxide is as high as 99.17%, and the boron content is 0.0069%.