company news about How to Improve the Purity of Silicon Carbide Powder

Silicon carbide powder is a kind of material commonly used in industrial production. In the actual use process, different industrial production has different requirements for the purity of the product. When the requirements for the purity are high, some methods should be adopted for purification. First use alkali washing, then adjust the acidity, excessive acid washing, and then adjust the acidity to PH=5-6 to filter, wash and dry, including the following steps:
Alkali washing: take the fine powder of processed black silicon carbide. The purity of black silicon carbide is 90? 95%, particle size D50=0.50~1 μ m, SiO2+Si content of 1~5% into the plastic bucket, add deionized water, add analytical pure sodium hydroxide, stir for 10~12 hours, and keep still for 10~12 hours; Adjust the acidity again, and conduct excessive pickling: add concentrated hydrochloric acid P=1.19g/cm3, the concentration is 38%, add hydrofluoric acid 1:1, add concentrated hydrochloric acid, stir for 10-12 hours, and keep still for 10-12 hours, add deionized water, stir, press filter, add deionized water, stir, press filter, repeat for 3-4 times, dry and crush after washing. This method of purifying silicon carbide powder is widely used because of its simple operation, low cost and high purity after purification.