摘要
利用NH4F与废白土中SiO2反应生成的(NH4)SiF6溶液和NH3,进行闭路循环反应,生成NH4F与水合SiO2(白炭黑),通过正交优化,得到最佳工艺为:氟化反应,NH4F∶废白土=1.28,NH4F∶水=0.9,反应温度60℃,反应时间4h;氨化反应,反应温度60℃,反应时间8h,投料比=2〔25%氨水mL/(NH4)SiF6g〕。循环试验结果表明,NH4F转化率可达82%,白炭黑产率达90%以上,只需补充少量NH4F和氨水,就能在不产生环境污染的情况下从废白土中制取白炭黑。
A closed cycle method for producing ammonium fluoride and hydrated silicon dioxide ( white carbon black) was practiced by using ammonium fluosilicate solution and ammonia gas,both produced from ammonium fluoride reacted with silicon dioxide of waste clay. The optimum conditions are: ammonium fluoride/waste clay = 1.28, ammonium fluoride/water = 0.9, T = 60℃ and t = 4h for ammonium fluoride reaction; T = 60℃, t = 8h and feeding ratio = 2 ( 25% ammonia liquid mL/ammonium fluosilicate g ) for ammonia reaction. The experimental results show that the conversion ratio of ammonium fluoride reaches 82% and the white carbon black production rate is over 90%. So, the white carbon black could be made from waste clay without environmental pollution so long as a little amount of ammonium fluoride and ammonia was added for each cycle.
出处
《中国环境科学》
EI
CAS
CSSCI
CSCD
北大核心
1998年第5期468-471,共4页
China Environmental Science
基金
国家自然科学基金
上海市教委科技发展基金
关键词
白炭黑
废白土
氨循环法
炼油厂
废物处理
white carbon black waste clay comprehensive utilization green chemistry