The extrartion of aluminum from coal mining waste(CMW) is an important industrial process.The two major problems in applications are low aluminum dissolution efficiency and high iron content in the raw material,which affect the quantity and quality of products.To improve the aluminum recovery process,the leaching kinetics of CMW with hydrochloric acid was studied.A shrinking core model was used to investigate aluminum and iron dissolution kinetics.Based on the kinetic characteristics,a process for recovering aluminum was proposed and tested experimentally.It is found that the aluminum leaching reaction is controlled by surface reaction at low temperatures(40-80℃) and by diffusion process at higher temperatures(90-106℃).The iron dissolution process is dominated by surface reaction at 40-100℃.The results show that iron could be dissolved or separated by concentrated hydrochloric acid.Fine grinding will improve aluminum dissolution significantly.
采用煤矸石制得的水玻璃为原料,通过二氧化碳碳化工艺制备出高比表面积的白炭黑。研究了工艺条件对白炭黑BET法比表面积及DBP吸收值的影响。研究结果表明,在水玻璃密度为1.074 5 g/m L、二氧化碳通气速率为80 m L/min、反应温度为80℃、乙醇浸泡10 h后常压干燥条件下,可得到比表面积为279.74 m2/g、DBP吸收值为2.93 m L/g且分散性较好的白炭黑颗粒。
