发明授权
US4057611A Process for recovering aluminum from alunite 失效
从铝酸钠中回收铝的工艺

Process for recovering aluminum from alunite
摘要:
An improvement in the process for the recovery of aluminum from alunite in which the alunite in particulate form is dehydrated, sulfur and alkali metal compounds removed from the dehydrated ore leaving a particulate residue containing aluminum values, the residue digested with at least one alkali metal hydroxide to convert the aluminum values to soluble aluminates, silicon removed from the soluble aluminate solution, and aluminum values precipitated from the aluminate solution, the improvement comprising: multiple stage digestion of the particulate residue accomplished by dividing the particulate residue into two fractions, digesting one fraction first and using the first stage liquor from the first digestion step to digest the remaining fraction. The fraction digested first may be the one having the smaller particle size, or the one having the larger particle size. The objective is to contact the caustic digestion liquor at its lowest aluminum content (lowest A/C ratio) with that fraction of the residue having the highest extractable aluminum content. The result is the production of a liquor for final recovery of aluminum values which has a higher aluminum to caustic ratio than that produced by prior digestion procedures. The improvement provides a higher recovery of aluminum from the alunite ore.
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IPC分类:
C 化学;冶金
C01 无机化学
C01F 金属铍、镁、铝、钙、锶、钡、镭、钍的化合物,或稀土金属的化合物 (金属氢化物入C01B 6/00; 卤素的含氧酸盐入 C01B 11/00; 过氧化物、过氧酸盐入 C01B 15/00; 镁、钙、锶或钡的硫化物或多硫化物入 C01B 17/42; 硫代硫酸盐、连二亚硫酸盐、连多硫酸盐入C01B 17/64; 含硒或碲的化合物入C01B 19/00; 金属与氮的二元化合物入 C01B 21/06; 叠氮化物入C01B 21/08; 金属氨化物入C01B 21/092; 亚硝酸盐入C01B 21/50; 磷化物入C01B 25/08; 磷的含氧酸盐入 C01B 25/16; 碳化物入C01B 32/90; 含硅的化合物入 C01B 33/00; 含硼的化合物入 C01B 35/00; 具有分子筛特性但不具有碱交换特性的化合物入C01B 37/00; 具有分子筛和碱交换特性的化合物,如结晶沸石,入C01B 39/00;氰化物入 C01C 3/08; 氰酸盐入 C01C 3/14; 氰氨盐入 C01C 3/16; 硫氰酸盐入 C01C 3/20; 发酵或使用酶的方法制备元素或二氧化碳之外的无机化合物入C12P 3/00; 从混合物,如矿石,制取作为提炼游离金属的冶金工艺中间化合物的金属化合物入C22B; 通过电解法或电泳法生产非金属元素或无机化合物入 C25B)
C01F7/00 铝的化合物
C01F7/02 .氧化铝;氢氧化铝;铝酸盐
C01F7/04 ..碱金属铝酸盐的制备;从碱金属铝酸盐制备铝的氧化物或氢氧化物(C01F7/028优先)
C01F7/06 ...用碱金属氢氧化物处理铝矿物或类似废物的原材料,例如根据拜耳法浸出铝土矿(从得到的铝酸盐溶液中获得氧化铝或氢氧化物入C01F7/14)
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