砷石膏渣中砷的嵌布特征及赋存状态研究

应用矿物解离分析MLA技术,对砷石膏渣样品进行详细的工艺矿物学分析,考察砷石膏渣的主要矿物组成、嵌布特征、共伴生关系等,并进行安全化处置研究。结果表明,砷石膏渣主要由十类17种物相组成,其中砷主要赋存在复杂氧化混合物和毒石中。完全解离的复杂氧化混合物颗粒占86.31%;完全解离的毒石颗粒占97.78%。安全化处理试验结果表明,砷石膏渣在1200℃以下可以使得其中的砷得到安全化固化,促使砷石膏渣由危险废物向一般二类工业固体废物转化。

Oxygen pressure acid leaching of artificial sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation

The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation was investigated in this study.Artificial sphalerite was fabricated with varying amounts of iron content via the sintering of ZnS and FeS and used for the pressure acid leaching experiment.The variations in the potential of the pressure leaching system were investigated by using a self-designed potential autoclave.The results showed that compared to the non-iron sphalerite,there was a violent redox reaction between the 25.70%Fe-artificial sphalerite and dissolved oxygen during the process of pressure leaching;and the catalytic mechanism was attributed to the redox couple Fe^3+/Fe^2+,where Fe3+oxidizes the H2S gas film and the reduced Fe2+state is subsequently oxidized by the dissolved oxygen.Furthermore,the effect of temperature,H2SO4 concentration,and oxygen partial pressure on the artificial sphalerite with different iron contents was studied.The sphalerite samples with iron content were observed to dissolve more easily in sulfuric acid compared to the non-iron samples.Moreover,the activation energy of artificial sphalerite was observed to be lower in the sample with 25.70%iron content(22.26 kJ/mol)compared to that with no iron(32.31 kJ/mol);and the apparent reaction orders were obtained with respect to H2SO4 concentration(1.10 and 1.36)and oxygen partial pressure(1.29 and 1.41),respectively.A comprehensive kinetic model was developed on the basis of the experimental data and the fitted leaching ratio plot;and the kinetic equations for the leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation were determined.

2015~2019年云南省城市空气质量特征及影响因素研究

利用2015~2019年云南省16个州市29188个空气质量日报数据进行数理统计,采用克里金插值法及Daniel趋势检验法分析AQI(空气质量指数)及主要污染物浓度的时空变化特征,探讨近5年云南省城市空气质量时空变化特征及其影响因素。结果表明:(1)2015~2019年云南省SO_(2)、PM_(2.5)、PM_(10)浓度呈下降趋势,NO_(2)浓度保持基本稳定,O_(3)浓度呈显著上升趋势,各年间空气质量综合指数值波动较小,且逐年改善。(2)2019年O_(3)-8h作为超标污染物占比达57.52%。云南省PM_(2.5)年均值相对较高区域面积略有减少,O_(3)年均值相对较高区域面积显著增加。(3)云南省PM_(2.5)与PM_(10)月均值呈现冬春高夏秋低的变化规律,O_(3)月均值为春季单峰高值,SO_(2)月均值整体趋势平稳变化幅度不大。(4)云南省AQI值及平均能见度和平均降水量呈显著负相关(P<0.01),AQI值与平均气温及平均风速不存在显著相关性。研究显示云南省空气质量优良逐年改善,污染类型由颗粒物污染转为以颗粒物和臭氧为特征的复合型污染。空气质量受气象条件影响,能源结构优化、污染物总量减排等措施对空气质量改善起到积极作用。

水热法褐煤浸取软锰矿研究

以硫酸为浸取液、褐煤为还原剂,采用水热法高效浸取软锰矿中的锰。研究了不同水热浸取温度、不同浸取时间对软锰矿浸取率的影响。结果表明,在(140~290)℃的浸取温度范围、(1~6)h的反应时间范围内,软锰矿的最佳浸取条件为:浸取温度230℃,浸取时间4 h,在此条件下浸取率达95%。

云南省汽车维修业维修过程挥发性有机物排放现状及预测研究

在云南省汽车维修业含挥发性有机物(VOCs)原辅材料使用现状调研基础上,采用排放因子法,自上而下计算云南省汽车维修企业VOCs排放量。通过情景预测法对云南省汽车维修企业VOCs排放情况进行预测。结果表明,调研的2314家汽车维修企业,VOCs排放量约为2797.10t。在此水平上,推算2018年云南省汽车维修企业VOCs排放量约为7198.35t;维持现有控制水平情况下,到2026年云南省汽车维修行业VOCs排放量将达到14131.64t。优化涉VOCs原辅材料使用类型及品质,提升末端治理措施效率,相比于现状VOCs减排率为53.76%。优化涉VOCs原辅材料使用类型及品质是控制云南省汽修行业VOCs减排的最佳选择。