Sb高效富集与As转化稳定化的砷碱渣清洁利用新技术工业试验

Industrial Test Study on the Clean Utilization Technology of Arsenic-alkali Residue with Sb Efficient Enrichment and As Conversion Stabilization

为了实现锑冶炼砷碱渣的清洁利用及无害化处置,设计了球磨浸出-重选收锑-废碱喷淋-氧化沉砷-砷稳定固化的砷碱渣清洁利用新工艺。结果表明:常温下液固比为4∶1时,砷碱渣经球磨后水浸,球磨和浸出时间分别20 min和40 min,As浸出率为96. 78%,碱浸出率为97. 35%,实现Sb、As和碱高效分离;为提取回收浸出渣中锑资源,通过摇床高效富集回收Sb,回收率为40%~50%,且精矿中As <1%,Sb≥10%,可通过冶炼系统回收;基于酸碱中和原理,浸出液(高砷废碱)进入锑冶炼中烟气脱硫喷淋系统与烟气中SO2发生反应,烟气中SO2和As含量达到排放标准,实现浸出碱液和烟气SO2协同治理目的;向高砷废水加入H2O2对砷进行氧化,再加入脱砷剂(生物制剂)与砷发生沉淀反应而脱除,经两段脱砷后,废水中As含量降低至150 mg/m3,脱砷效率分别为88. 4%和92. 5%;产生的脱砷渣采用铁盐稳定剂处理,在添加质量比为9%时固化体As毒性浸出浓度从348. 67 mg/L降至0. 65 mg/L,达到危险废物填埋场入场标准。工业扩大试验结果表明,新工艺可达到以废治废、清洁利用砷碱渣目的。

In order to achieve clean utilization and harmless disposal of antimony smelting arsenic-alkali residue,a new process for cleaning arsenic-alkali residue of"ball mill leaching-recovery of antimony by gravity-waste alkali spray-arsenic precipitation by oxidation-stable solidified arsenic"was proposed. The results showed that the efficient separation of Sb,As and alkali with the As leaching rate of 96. 78% and alkali leaching rate of 97. 35% could be realized under the arsenic-alkali residue with the liquid-solid ratio of 4 ∶1 grounded in a ball mill for 20 minutes and then leached for 40 minutes at room temperature. In order to extract the antimony from the recovered leaching slag,the shaking table was used to recover Sb with the recovery of 40% ~ 50%,and the As content in the concentrate was less than 1%,and the Sb content was greater than or equal to 10%,which could be recycled through the smelting system. Based on the principle of acid-base neutralization,the leachate( high-arsenic waste alkali) entered the flue gas desulfurization spray system in the smelting process and reacted with SO2 in the flue gas. Therefore,the content of SO2 and As in the flue gas could reach the discharge standard and the purpose of synergistic treatment of leaching lye and flue gas SO2 was achieved. After high-arsenic wastewater was added to H2O2 to oxidize arsenic,and then arsenic removal agent( biological agent) was added to precipitate with arsenic,the As content in the wastewater was reduced to 150 mg/m3,and the two stages of the arsenic removal efficiency could reach 88. 4% and 92. 5%,respectively. The resulting arsenic removal slag was treated with an Fe-contained stabilizer. When the mass ratio of addition was 9%,the toxicity leaching concentration of the solidified As was reduced from 348. 67 mg/L to 0. 65 mg/L,which reached the entry criteria for hazardous waste landfills. The results of the industrial expansion test showed that the new process could achieve the purpose of waste treatment and clean utilization of arsenic-alkali slag.