Method for preparing hollow nanometer white carbon black microsphere from polycrystalline silicon by-product SiCl4

Abstract

The invention provides a method for preparing a hollow nanometer white carbon black microsphere from a polycrystalline silicon by-product SiCl4. The method comprises the following steps: preparing an ammonia water solution with a concentration of 1 to 3 mol / L, separately adding polyvinylpyrrolidone (PVPK30), polyoxyethylene fatty alcohol sodium sulfate (AES) and sodium hexametaphosphate accounting for 0 to 0.3% of the total mass of the ammonia water solution, bubbling gaseous SiCl4 into the ammonia water solution for a reaction in virtue of dilution with clean air, wherein reaction temperature and a stirring rate are controlled to be 40 to 50 DEG C and 150 to 250 r / min, respectively and stopping introduction of the mixed gas of SiCl4 and air when the pH value of the solution is about 7.5; and subjecting a crude product to ageing for 8 h, filtering, washing and drying at 105 DEG C so as to prepare the hollow nanometer white carbon black microsphere. Waste liquid containing ammonium chloride is concentrated and purified so as to prepare agriculture fertilizer.

Description

1 technical field [0001] The invention belongs to the field of inorganic functional materials, and relates to a method for preparing hollow nanometer white carbon black microspheres, which adopts a liquid phase bubbling method to prepare hollow nanometer white carbon black microspheres with a hollow structure, small particle size and good dispersibility. 2 background technology [0002] With the rapid development of the global photovoltaic industry, the polysilicon industry has developed rapidly. At present, the domestic polysilicon production mainly adopts the improved Siemens method, and every 1t of polysilicon produced will produce about 12t of by-product silicon tetrachloride (SiCl 4 ). SiCl 4 It is easily hydrolyzed in humid air to generate silicic acid and hydrogen chloride, which is extremely polluting to the environment, and improper treatment will cause serious environmental pollution. How to turn waste into treasure and rationally utilize SiCl 4 It is the key t...

AI Technical Summary

Problems solved by technology

But SiCl 4 There are two significant problems in the preparation of silica: one is SiCl 4 The nature is relatively active and the reaction is too violent; the second is that the obtained products have different particle sizes, the agglomeration is more serious, and the affinity with organic polymers is poor, which affects the improvement of the mechanical properties of composite materials.