矿化剂对水热合成ZnS晶体结构及可浮性的影响

Effect of mineralizer on crystal structure and floatability of ZnS formed in hydrothermal sulfidation

以某冶炼厂含锌废渣为研究对象,通过在水热硫化过程中添加矿化剂调控人造硫化矿晶体结构,提高人造硫化矿的可浮性。研究结果表明:添加矿化剂Na Cl时,Na Cl浓度0.1 mol/L为最佳浓度,Zn富集比从1.16提高到1.36;添加矿化剂CH3COONa时,CH3COONa浓度0.5 mol/L为最佳浓度,Zn富集比从1.16提高到1.62;添加矿化剂EDTA-2Na时,0.1 mol/L EDTA-2Na为最佳浓度,Zn富集比从1.16提高到1.69。矿化剂的添加对Zn回收率无明显影响,回收率仍在60%左右。添加矿化剂Na Cl后,Zn S晶粒粒度从21.0 nm提高到35.9 nm;添加矿化剂CH3COONa使Zn S晶粒粒度从20.8 nm提高到35.3 nm;添加矿化剂EDTA-2Na使Zn S晶粒粒度从21.4 nm提高到37.6 nm。0.1 mol/L的EDTA-2Na为最优矿化剂。在添加上述矿化剂后,Zn S晶体颗粒由无定型的絮状颗粒转变为致密粗大的颗粒,且加入矿化剂有利于减小Zn S与Ca SO4晶体的团聚夹杂现象,从而有利于水热合成人造硫化锌晶体的浮选分离。

In order to modify the crystal structure and improve the floatability of synthetic metal sulfide, mineralizers were added during the hydrothermal sulfidation of Zn-contained residue, discharged from a smelting plant. The results show that the enrichment ratio of ZnS increases from 1.16 to 1.36 after adding 0.1 mol/L NaCl, the enrichment ratio of ZnS increases from 1.16 to 1.62 after adding 0.5 mol/L CH3 COONa, and the enrichment ratio of ZnS increases from 1.16 to 1.69 after adding 0.1 mol/L EDTA-2Na. The grain size of ZnS crystal increases from 21.0 nm to 35.9 nm after adding NaCl, increases from 20.8 nm to 35.3 nm after adding CH3 COONa, and increases from 21.4 to 37.6 nm after adding EDTA-2Na. As a result it is concluded that EDTA-2Na is the optimal mineralizer, and the optimum concentration is 0.1 mol/L. The amorphous flocculent particles of ZnS turn into dense massive ZnS after the addition of mineralizers, and distinct decrease of the agglomeration between ZnS and CaSO4 can be observed, which is in favour of the flotation and separation of artificial sulfur ore.