某选矿厂工业回水中离子对黄铁矿浮选的影响机制

Influence Mechanism of Ions in Industry Backwater of Concentrator on Floatability of Pyrite

通过黄铁矿纯矿物浮选实验、紫外分光光度计(UV-Vis)分析、Zeta电位测定和傅里叶变换红外光谱(FT-IR)分析研究了工业回水中超标离子(NH+4,Mg^(2+),Ca^(2+),F-)对黄铁矿浮选的作用机制。结果表明,回水中NH_4^+可以提高矿物表面的电位,扩大黄铁矿浮选的pH值范围,红外光谱表明其能促进黄铁矿与黄药发生化学吸附,且矿物表面黄药吸附量随着NH+4的增加而增加,经NH_4^+活化后,黄铁矿浮选回收率提高15.5%。而回水中Ca^(2+),Mg^(2+),F-会抑制黄铁矿对黄药的吸附,浮选回收率平均下降10%。其中,Ca^(2+),Mg^(2+)在黄铁矿表面易形成亲水膜,阻碍黄铁矿对黄药的表面吸附;Zeta电位测试发现F-吸附在矿物表面导致矿物表面带负电,与同为阴离子的黄原酸根离子形成竞争吸附,减少了黄原酸盐在黄铁矿表面的吸附量,降低了其可浮性。

The action mechanism of over proof ions （ NH4 , Mg2 ＋ , Ca2 ＋ , F- ） in industry backwater to flotation of pyrite was inves- tigated by pure mineral flotation tests, ultraviolet visual （ UV-Vis ） spectrophotometer, Zeta potential and Fourier transform infrared spectroscopy （FT-IR） spectra measurements. The results showed that NH4 in backwater made the potential of mineral surface increase and extended the range of pH values of pyrite flotation. FT-IR spectra results showed that NH4 also made xanthate chemisorb on pyrite surface, and adsorption quantity increased with NH/concentration increasing. The flotation recovery rate increased by 15.5% after ac- tivation of NH4 . While Mg2 ＋ , Ca2 ＋ and F - in backwater inhibited the adsorption of xanthate on pyrite surface, the flotation recovery rate decreased by 10% on average. Mg2＋ and Ca2＋ easily formed hydrophilic membranes on pyrite surface to hinder xanthate adsorp- tion; F- adsorption on mineral surface could make mineral surface be negatively charged, which was found by Zeta potential test, and thus formed a competitive adsorption between xanthate ion and F , both being anions, and reduced xanthate adsorption on pyrite sur- face, so floatability of pyrite decreased.