钙化焙烧与湿法酸浸提钒废渣浸出毒性研究

On the leaching toxicity of the calcified roasting and the wet acid leaching of the vanadium slag

对钙化焙烧和湿法酸浸提钒废渣的化学成分和矿物组成进行分析,主要含SiO2、Al2O3、Fe2O3及少量其他氧化物,矿物组成主要为石英。研究在不同pH值浸提剂作用下两种钒渣的重金属浸出毒性,探讨以超纯水为浸提剂时重金属的浸出规律。利用发光细菌试验和种子发芽试验研究两种钒渣浸出液的生物毒性。结果表明:以pH值为4.0、4.5、5.0、5.5、6.0、6.5、7.0的稀H2SO4溶液和超纯水为浸提剂时,除V与As外,湿法酸浸钒渣的重金属浸出质量浓度均高于钙法钒渣;两种钒渣浸出液的pH值都较稳定。发光细菌试验和种子发芽试验结果均表明,湿法酸浸钒渣浸出毒性比钙法钒渣浸出毒性强。

The present paper aims at detecting the leaching toxicity of the calcified roasting and the wet acid leaching of the vanadium slag. For our research purpose, we have done experiments with the chemical compositions and XRD atlas of the residue from the calcium roasting （in the Hengfeng Mining Co. , LTD in Sansui County, Guizhou） and analyzed the wet acid dissolution vanadium in the Smelting Processing Center （under the Central Laboratory of Geo-Mineral Resources in Guizhou） . As a result, we have found that the XRD atlas of the residue from the calcium roasting mainly contains SiO2, Al2O3, Fe2O3 and some of other oxides, with its chief mineral content being quartz. At the same time, we have also done the contrast tests on the heavy metal leaching toxicity of the extracting agents under different pH values, while investigating the regularity of the heavy metal exracts by using the extremely pure water as leaching agent. Further more, we have investigated the biological toxicity of the two leaching solutions of vanadium slag through luminescent bacteria and seed-ger- minating experiments. The results we have gained from the above experiments demonstrate that, when using the sulfuric acid solution of pH=4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0 and the extremely pure water as the leaching agent, it was possible for us to obtain higher leaching concentrations of heavy metals of wet vanadium slag than those of the calcified vanadium slag besides the contents of V and As. Under such conditions, the pH value of the two leaching solutions of vanadium slag turned to be relatively stable （that is to say, the pH value of the leaching solution of the wet vanadium slag was about 5, whereas that of leaching solution of calcified vanadium slag was about 7）. At the same time, we have compared the effects of the two leaching solutions of the vanadium slag on the seed germination, trying to determine the relative luminosity factors influencing the seedling growth, the peroxidase （POD）, the catalase（CAT） and the superox- ide dismutase（SOD） of the seedling, in addition to the luminescent bacteria. Finally, we have arrived at the conclusion that the leaching toxicity of wet acid leaching vanadium tends to be higher than the cal- cified roasting V-slag on the condition that the leaching solution of the wet vanadium slag was keeping the liquid discharge with the moderate toxicity, in comparison with the low toxicity liquid of the calcified vanadium slag.