铝电解质中的钾脱除技术

针对我国西南地区铝电解质中钾含量偏高的问题，提出了铝电解工序钾脱除技术方案。根据某电解铝企业的实际情况，通过取样分析、理论推导，以及浮选分离试验，提出了具体的实施方案，并论证了方案的可行性。研究结果表明：电解质中的KF易挥发并以KAlF4和K2NaAl3F12、K2NaAlF6等固体氟铝酸盐的形态进入铝电解烟气；不同企业的铝电解质中KF含量不同，但电解槽挥发物中KF含量却比较接近；采用收集装置将铝电解烟气中的固体挥发物收集走，使其不再混入载氟氧化铝进入电解槽中，可快速降低铝电解槽中KF的平衡浓度；固体挥发物通过浮选可分离其中的氧化铝和氟铝酸盐，氟铝酸盐可用于制备低温电解质。该方案在技术上具有可行性。

Removal Technology of Potassium from Aluminum Electrolyte

Address to the high potassium content in aluminum electrolyte in Southwestern China, a technology scheme of potassium removal in aluminum electrolytic process was proposed. According to the actual situation of an electrolytic aluminum enterprise, through sampling analysis, theoretical deduction and flotation separation test, the concrete implementation scheme was put forward, and the feasibility of the scheme was demonstrated. The results show that KF in aluminum electrolytes is volatile and enters the electrolytic flue gas in form of solid fluoroaluminates such as KAlF4, K2NaAl3F12 and K2NaAlF6. The content of KF in aluminum electrolytes of different enterprises is different, but the content of KF in the volatiles of electrolyzer is similar. The equilibrium concentration of KF in aluminum electrolytic cell can be reduced rapidly by collecting the solid volatiles in aluminum electrolytic gas so that it can no longer be mixed with fluorinated alumina and entering the electrolytic cell again. The high potassium fluoroaluminates, which is separated from the collected solid volatiles by flotation method, can be used to prepare low temperature electrolytes. The scheme is technically feasible.