焙烧酸浸联合处理电镀高铬污泥高值化利用研究

High value utilization method of electroplating high concentration chromium sludge treated by roasting and acid leaching

采取焙烧-酸浸方法处理电镀铬污泥生成高纯度绿铬矿(Cr_(2)O_(3)),达到将危险废物处理后变成高附加值产品资源化利用的目的.考察了焙烧温度、酸种类、酸浓度及酸浸次数对电镀铬污泥中硫酸钠和其他重金属杂质去除的影响规律,确定最佳工艺方法及参数为1 mol·L^(-1)盐酸酸浸预处理-空气600℃焙烧2 h-3 mol·L^(-1)盐酸酸浸处理-水洗处理.经过处理后,电镀铬污泥中Na_(2)SO_(4)去除率在99%以上,产品Cr_(2)O_(3)纯度可以达到99%,平均粒径为40 nm,所制备的纳米级Cr_(2)O_(3)符合工业三氧化二铬行业标准一类优等品指标要求.产品有望用于等离子喷涂、颜料生产等领域,方法可为电镀铬污泥资源化及提高企业效益提供参考.

The chromium plating sludge was treated via a roasting-leaching method to produce high-purity eskolaite(Cr_(2)O_(3))aiming at turning hazardous waste into high value-added products for resource utilization.The effects of roasting temperature,acid types,acid concentration and leaching times on the removal of sodium sulfate and heavy-metal impurities in electroplating chromium sludge were investigated.The result showed that the optimal processes and experimental parameters were leaching pretreatment(1 mol·L^(-1) HCl)-roasting in the air(600℃-2 h)-leaching treatment(3 mol·L^(-1) HCl)-water washing treatment.More than 99%of Na_(2)SO_(4) removal rate was achieved and the high-purity of Cr_(2)O_(3)(over 99%)with an average particle size of 40 nm can be obtained.This high-purity Cr_(2)O_(3) met the stander requirement of the first quality of industrial grade Cr_(2)O_(3),which is expected to be used as a raw material in plasma spraying and pigment production.This provides a reference for the utilization of chromium plating sludge and improvement of enterprise benefits.