Fundamental Study on the Recovery of Functional Double Oxides from Slicing Dusts by Flotation Method

为了从切片粉尘中回收功能双氧化物，采用醋酸十二烷基铵（DAA）作为捕收剂，对绿碳化硅（GC）中的钆镓石榴石（GGG）、钇铝石榴石（YAG）和铌酸锂（LN）进行了浮选试验。结果表明：(1)GGG、YAG和LN在pH为7.3、7.5和2.8时存在等电点；(2) GGG或YAG的可浮性在碱性范围内高，其表面带负电；在酸性范围内低，其表面带正电。然而，在酸性pH范围内，当硫酸盐或草酸盐离子特异性吸附在表面时，可浮性增强，导致DAA吸附量增加。(3)虽然在较宽的pH范围内，GC的可浮性较高，但在酸性pH范围内，玉米淀粉的存在显著降低了GC的可浮性。(4)在pH < 2的条件下，以硫酸或草酸为活化剂，玉米淀粉为抑制剂，可以选择性地从GC中浮选GGG或YAG。(5)在酸性pH范围内，多价阴离子、硫酸盐或草酸盐离子存在时，LN的可浮性较低，但氟离子的加入增强了LN的可浮性。(6)在2 ~ 4的pH范围内，在氟化钾和玉米淀粉的存在下，LN可以选择性地从气相色谱中浮出。

In order to recover functional double oxides from slicing dusts, flotation of gadolinium gallium garnet(GGG), yttrium aluminum garnet(YAG)or lithium niobate(LN)from green carborundum(GC)has been investigated, using dodecylammonium acetate(DAA)as a collector. The results obtained are as follows :(1)The isoelectric points of GGG, YAG and LN exist at pH 7.3, 7.5 and 2.8, respectively.(2)The floatability of GGG or YAG is high in the alkaline pH range where the surf ace of GGG or YAG is negatively charged and low in the acidic pH range where the surface is positively charged. However, the floatability in the acidic pH range is enhanced in the presence of sulfate or oxalate ions which are specifically adsorbed on the surface, resulting in the increase of DAA adsorption.(3)Although the floatability of GC is high in the wide pH range, it is remarkably depressed in the presence of corn starch in the acidic pH range.(4)GGG or YAG can be selectively floated from GC at pH below 2 by using sulfuric acid or oxalic acid as an activator and corn starch as a depressor.(5)The floatability of LN is low in the acidic pH range in the presence of multivalent anions, sulfate or oxalate ions, but it is enhanced by adding fluoride ions.(6)LN can be selectively floated from GC in the pH range of 2 to 4 in the presence of potassium fluoride and corn starch.