铝电解槽废旧阴极炭块中有价组分的回收

铝电解槽废旧阴极炭块是铝电解生产最大宗的固体废弃物，并且是含氟量极高的危险固体废料，严重污染周围的环境.采用水洗—化学浸出—煅烧工艺回收铝电解槽废旧阴极炭块中的氟化物和碳粉，采用硫酸铝溶液浸出废旧阴极炭块，实验得到适宜的浸出条件为25℃浸出24h，碳的回收率达到88%，最终产物碳的纯度从61.3%提高到89.6%.考察了溶液温度、溶液pH值和时间与氟回收率之间的关系，浸出溶液中氟化物以Al₂((OH)_0.46F_0.54)₆H₂O和Na₅Al₃F₁₄形式析出，回收的最佳条件为溶液温度90℃，pH值为5.5，180min得到氟离子回收率最大为99.7%，高温煅烧后所得产品为AlF₃和Na₅Al₃F₁₄.

Recovery of Valuable Components from Spent Pot-Lining of Aluminium Electrolytic Reduction Cells

Spent pot-lining(SPL)of aluminium electrolytic reduction cells is currently the largest hazardous solid waste with high fluoride content in aluminium industry， which pollutes the surrounding environment seriously. Fluoride and carbon from SPL were recovered by water wash， chemical leach and calcination process using Al₂(SO₄)₃·18H₂O solutions. The results show that the appropriate leaching conditions were time of 24h at 25℃， the recovery rate of carbon is 88% from SPL， and the carbon purity increases from 61.3% to 89.6%. The effects of time， temperature and pH value of solution on recovery rate of fluorine were investigated. Fluoride can be precipitated as Al₂((OH)_0.46F_0.54)₆H₂O and Na₅Al₃F₁₄. The appropriate conditions of fluoride recovery were temperature of 90℃， pH value of 5.5 and time of 180min. The maximum fluorine recovery rate is 99.7%. The main products were AlF₃ and Na₅Al₃F₁₄ after calcination.