Extraction of Amorphous Silicon from Fly Ash and High Value Utilization of Silicon Products

Coal-based energy structure of China has not only guaranteed energy supply, but also brought a lot of fly ash, because of the low utilization rate of fly ash has caused serious environmental pollution and farmland occupation problems, especially in Northwest China. At present, the extraction of useful components has become a research hotspot of high-value utilization of fly ash, especially the extraction of amorphous silicon in it an important means to improve the value of resource utilization of fly ash. In this paper, two main processes of extracting amorphous silicon from fly a share described, namely alkali leaching and acid leaching. The principle and characteristics of the process are analyzed and the application of products by silicon extraction in the insulation material, silica black, molecular sieve, filling of paper and rubber is discussed. Compared with the products of traditional silicon-based, the various of silicon-based products prepared by fly ash have the advantages of better performance, lower cost and more wider application, which can be regarded as an effective way to realize the high-value, fine and cascade utilization of fly ash.