摘要
微硅粉作为冶炼工业硅或硅铁合金的烟尘副产品,其主要成分为无定形二氧化硅,同时存在少量游离碳及金属氧化物。由于其火山灰活性高、比表面积大等物理特性,可被广泛应用于混凝土、水泥、耐火材料等领域。与国外微硅粉相比,国内微硅粉无法同时满足纯度高及粒度小的要求,因此制约了其大规模的应用。然而,大量球形的二氧化硅颗粒在微硅粉的形成过程中被除尘装置所收集,这就为制备高纯球形二氧化硅提供了廉价易得的硅源。高纯球形二氧化硅是制备半导体集成电路与器件的关键材料之一,是国内粉体研究的热点。若将微硅粉加以提纯得到高纯球形二氧化硅,在一定程度上可改善我国对高纯球形二氧化硅依赖于进口的局面。研究表明,提高微硅粉中SiO 2的品位是提高其附加价值与经济效益的途径之一。通过高温煅烧达到碳的着火点,可有效去除微硅粉中游离的碳杂质。而利用微硅粉易与碱性介质反应,不溶于酸性溶液(氢氟酸除外)这两个特点,可去除微硅粉中的金属氧化物杂质。此外,利用选矿等手段也可对微硅粉中存在的杂质进行不同程度的去除,以达到提纯的效果。本文概述了微硅粉在混凝土、水泥、耐火材料等领域的应用,总结了其作为添加剂的效果及作用机理,并分析了微硅粉的多种提纯方法,如煅烧法、湿法、絮凝法等,进而分析了各种提纯方法的优劣。结果表明,湿法提纯微硅粉技术可有效提高微硅粉纯度至99.98%以上,能够成为微硅粉提纯发展的主流方向。
Silica fume is a by-product produced in the metallurgical grade silicon(MG-Si)and ferrosilicon alloy production process.The main component is amorphous silica with small amount of free carbon and metal oxide impurities.Silica fume have been widely used in the field of concrete,cement and refractory materials due to its physical properties such as high volcanic ash activity and large specific surface area.However,silica fume is fail to utilize in large-scale application because its low-purity and large particle sizes,compared with foreign countries.Interestingly,sphe-rical silica particles,which collected in the dust removal device during the production of MG-Si,is a cheap and readily available source of silica for preparing the high purity spherical silica.High purity spherical silica is one of the key materials for semiconductor integrated circuit devices preparation,and it has been a focal point in powder material research field in China.If high purity spherical silica could be obtained from silica fume,it would greatly solve the problem of high purity spherical silica shortage in China.Many published studies have been demonstrated that the grade of SiO2 in silica fume was improved,which is one of the approaches to increased value-added and economic benefits of silica fume.The free carbon in silica fume can be effectively removed by calcining at a high tempe-rature.Meanwhile,silica fume can easily react with alkaline medium,and metal oxide impurities also can be leached in acid solution(except hydrofluoric acid),which can effectively improve its purity.In addition,the purity of silica fume can be significantly achieved by other beneficiation methods.This paper comprehensively elaborated the application fields of silica fume,including concrete,cement,refractory materials and etc.And then its additive effect and mechanism were summarized.Furthermore,the purification technology of silica fume were analyzed,such as calcination,acid,wet and flocculation.Based on the literature investigation,the results indicated tha
作者
王杰
魏奎先
马文会
伍继君
WANG Jie;WEI Kuixian;MA Wenhui;WU Jijun(National Engineering Laboratory for Vacuum Metallurgy,Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,Kunming University of Science and Technology,Kunming 650093,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2020年第23期23081-23087,共7页
Materials Reports
基金
云南省重大科技专项(2019ZE007)
云南省创新人才计划(2018HB009)
中国教育部创新研究团队(IRT-17R48)。
关键词
工业微硅粉
提纯
高纯球形二氧化硅
industrial silica fume
purification
high purity spherical SiO2
