云南某选煤厂浮选精煤焙烧工艺深度降硫研究

经过对云南某选煤厂煤泥进行浮选,获得含硫为1.36%(质量分数,下同)的浮选精煤,其中有机硫含量占全硫含量的82.35%,利用物理分选方法进一步脱硫比较困难.采用低温隔绝空气焙烧方法进行煤泥降硫,研究不同焙烧条件对浮选精煤降硫的影响规律,结果表明:在磷基复合药剂(DP)用量为5%,焙烧温度为450℃,焙烧时间为40 min,焙烧物料球团直径为小于9mm的综合焙烧条件下,浮选精煤中的硫含量降至0.30%以下,降硫效果显著,其他有害元素磷和砷等的含量也较低.     

聚丙烯酸钠对蛇纹石浮选的影响及其机理

通过浮选实验、Zeta电位测试、红外光谱分析和SEM-EDS分析等方法,系统地研究了聚丙烯酸钠（PAAS）对蛇纹石浮选行为及其表面性质的影响,并探讨其机理。浮选结果表明,添加抑制剂聚丙烯酸钠能有效抑制蛇纹石上浮,在加入24.7 mg/L的聚丙烯酸钠后,蛇纹石的浮选回收率由36%下降到10%;Zeta电位测试结果表明,聚丙烯酸钠能够显著降低蛇纹石的表面电荷;红外光谱和SEM-EDS分析结果表明聚丙烯酸钠在蛇纹石表面有明显的化学吸附。机理研究分析表明,聚丙烯酸钠通过与蛇纹石表面上的Mg²⁺作用对蛇纹石产生絮凝作用,改变蛇纹石颗粒的分散状态,从而实现对蛇纹石颗粒的有效抑制。     

Preparation,Characterization, and Catalytic Performance of MoS_2 Photocatalyst

The hydrothermal method was used to prepare MoS_2 photocatalyst with the raw materials of MoO_3 and KSCN, and the prepared products were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM). The catalytic performance of MoS_2 photocatalyst obtained at different reaction temperatures was studied, meanwhile the effects of different concentrations and different pH on degradation rate of methylene blue(MB) were investigated. The results show that those prepared photocatalyst samples are of nanometer scale, which exhibits better photocatalytic activity. When preparing MoS_2 photocatalyst, the higher temperature of the hydrothermal reaction, the greater the photocatalytic performance will be, and the crystallinity can be higher as well. As for degrading MB, the higher the concentration of MB is, the worse the degradation effect will be. The prepared photocatalyst was observed to show better degrading performance for MB solution under acidic condition, when pH was taken into consideration.     

利用氟化钠消除蛇纹石对黄铁矿浮选不利影响的机理研究

通过浮选试验、Zeta电位测试、SEM-EDS测试、X射线光电子能谱(XPS)测试研究了氟化钠在蛇纹石/黄铁矿体系中的作用机理。蛇纹石是硫化铜镍矿中的主要脉石矿物,不仅会抑制硫化矿物的浮选,而且会进入浮选精矿使后续的冶炼成本增加,因此需要利用氟化钠来消除蛇纹石对黄铁矿浮选的不利影响。研究结果表明,氟化钠可以显著改变蛇纹石的表面电位,使蛇纹石和黄铁矿由原来的静电吸引变为静电排斥,使黄铁矿在蛇纹石存在条件下的浮选回收率由41.2%提升至82.5%。其机理是氟化钠可以与蛇纹石表面的Mg(OH)_(2)反应生成MgF_(2),减少蛇纹石表面暴露的Mg^(2+),从而改变蛇纹石的表面电位,提高黄铁矿的浮选回收率。