煅烧活化粉煤灰对镓酸浸效果的实验研究

Study on acid leaching of gallium from fly ash activated by calcination

通过高温煅烧法对粉煤灰进行活化,采用酸浸法浸取活化后粉煤灰中的镓。研究了煅烧条件(助剂种类、助剂含量、煅烧温度、煅烧时间)对粉煤灰中镓的浸出效果的影响。采用X射线衍射表征粉煤灰以及不同煅烧条件下所得产物的物相组成,用ICP测定了浸取液中的镓的含量。研究结果表明:在3种助剂(碳酸钠、碳酸钙和氧化钙)中,碳酸钠是粉煤灰活化的最优助剂;碳酸钠与粉煤灰的质量比为1.5∶1、煅烧温度为800℃、煅烧时间为120 min时,粉煤灰中镓的浸出量(质量分数)为5.262×10-5。

Acid leaching of gallium from fly ash activated by calcination method was studied.The influences of different calcination conditions,such as variety of additives,contents of the additives,calcination temperature,and calcination time,on the leaching effect of gallium were investigated.The phase composition of fly ash and the samples obtained under different calcination conditions were characterized by XRD and the content of the gallium in the leaching liquid was determined by ICP.Results showed that sodium carbonate was the optimal additive for activating fly ash in the three kinds of additives（sodium carbonate,calcium carbonate,and calcium oxide）;when the calcination temperature was 800 ℃,calcination time was 120 min,and mass ratio of fly ash and sodium carbonate was 1 ∶1.5,the leaching content（mass fraction） of gallium from fly ash was5.262×10^-5.