摘要
采用硫酸锌沉淀工艺处理某黄金冶炼厂的高铜氰化提金废水,考察了沉淀剂用量、沉淀时间及沉淀温度对各离子沉淀率的影响,采用X射线衍射(XRD)分析对沉淀物进行分析表征,并对沉淀过程进行了理论分析和计算。研究表明,沉淀时间和温度对沉淀效果影响不大,而硫酸锌用量的影响较为显著。随着硫酸锌用量的增加,废水中游离氰与Cu离子浓度逐渐减小,Zn离子浓度逐渐增加。在100 ml氰化废水加入3.5 g Zn SO4,常温搅拌40 min的条件下,Fe,Cu离子及游离氰的沉淀率分别可达到100%,86%和99.34%。沉淀过程溶液中金基本没有损失,处理后的废水可在调节p H值后直接返回浸出系统循环利用。XRD分析表明,硫酸锌用量对沉淀物的组成没有影响,沉淀物组分主要为Zn2[Fe(CN)6],Zn(CN)2和Cu CN,可进一步通过化学方法处理综合回收金属铜、锌与游离CN-。理论计算表明,溶液中游离的CN-,Fe及Cu离子沉淀的极限浓度分别为3.83×10-3,1.56×10-13和2.37 mg·L-1,而处理后废水中的离子实际浓度要高于理论极限浓度,离子的沉淀次序依次为Zn离子、Fe离子、游离CN-和Cu离子。
The cyanide wastewater with high copper content in a gold smelter was treated by precipitation process. The effects of pre- cipitant dosage, settling time, and temperature on sedimentation rate were mainly studied. The precipitation was characterized by X-ray diffraction (XRD) and the sedimentation process was theoretically analyzed and calculated. The results showed that the settling time and temperature had few effects on the precipitation, but the influence of amount of zinc sulfate was more significant. With the amounts of zinc sulfate increasing, the concentration of copper ions and free cyanide decreased gradually, but the concentration of zinc ions in- creased gradually. When 3.5 g ZnSO4 was added to 100 ml cyanide water when stirring at room temperature for 40 min, iron ions, cop- per ions and free cyanide precipitation rates reached up to 100% , 86% and 99.34% , respectively. The precipitation process had no effect on the gold content and the treated wastewater could be recycled back to the system directly after adjusting the pH value. XRD a- nalysis showed that the amount of zinc sulfate had no effect on the composition of the precipitate and the precipitate was primarily com- posed of Zn2 [ Fe(CN) 61 , Zn(CN) 2 and CuCN. So Cu, Zn and CN- could be recovered by further processing from the precipitate. Theoretical calculations showed that when free CN -, Fe and Cu ions precipitated, the limit concentrations of these ions in the solution were 3.83 ×10-3, 1.56 × 10-13 and 2.37 mg·L-1, respectively; but the actual concentration of ions in the treated waste water was higher than the theoretical value, and the order of precipitation was zinc ion, iron ion, free cyanide and copper ions.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2015年第4期357-364,共8页
Chinese Journal of Rare Metals
基金
国家自然科学基金青年基金项目(51204130)
陕西省教育厅重点实验室专项项目(13JS059)资助
关键词
氰化废水
硫酸锌
沉淀
高铜
cyanide-containing waste water
ZnSO4
precipitation
high density copper