典型钢渣的易磨性和胶凝活性分析

分析了25家钢铁企业转炉和电炉钢渣的易磨性和胶凝活性,分析结果表明,钢渣中的一些含铁物相,如橄榄石、铁酸钙类物质属于难磨物相,而RO相相对易磨,电炉氧化渣比转炉渣易磨,热闷渣比热泼渣易磨;碱度≥1.8的转炉钢渣的胶凝活性较好,能符合GB/T 20491—2006《用于水泥和混凝土中的钢渣粉》中规定的二级钢渣粉的活性指数要求,而电炉渣由于碱度偏低,胶凝活性较差。     

Heavy metals fraction and ecological risk evaluation in municipal solid waste gasification slag non-burnt bricks

The heavy metals in non-burnt bricks made from municipal solid waste (MSW) gasification slags with a modified European Bureau Community of Reference procedure were studied. Heavy metals were present in the form of oxidizable and residual fractions, which were stable and not easy to dissolve. The preparation process of non-burnt bricks displayed prominent solidification effect for some heavy metals in the gasification slag. The solidified rate for metals, such as As, Cd, Cr, Ni, and Zn reached 89.82%, 79.57%, 73.64%, 66.73%, and 88.05%, respectively. Moreover, the leaching concentrations of eight heavy metals were all below 8 mg/kg. On the basis of these observations, the risk of exposure to heavy metals in non-burnt bricks was evaluated using the solidification formula and the leaching concentration of heavy metals combined with the assessments of the Hakanson potential ecological risk and pollution ratio of secondary phase and primary phase. Results showed that the preparation of MSW gasification slag non-burnt bricks was not harmful to the environment, but attention is warranted for possible migration of heavy metal cadmium (Cd) in the long term, which may result in an impact on the ecological environment.     

高炉水淬渣吸附Zn~(2+)的平衡与动力学研究

研究了Zn~(2+)在高炉水淬渣(WBFS)上的吸附情况,并用电镜扫描(SEM)、电感耦合等离子体质谱分析仪(ICP)及X射线衍射仪(XRD)等对高炉水淬渣的理化性质进行了表征.通过批量平衡实验,从动力学和热力学角度探讨了Zn~(2+)在高炉水淬渣上的吸附作用机理.结果表明:吸附等温线能较好地用Langmiur模型来描述,分离因子RL值介于0~1之间,属于优惠吸附.ΔH和ΔS值分别为52.45 k J·mol~(-1)和167.52J·mol~(-1)·K~(-1),表明Zn~(2+)在高炉水淬渣上的吸附是吸热过程,并且吸附过程增加了系统的混乱度,而ΔG值仅仅在温度高于318 K后才为负值,说明高炉水淬渣对Zn~(2+)吸附的自发性与温度成正比.吸附动力学很好地符合伪二级动力学模型,以化学吸附为主.高炉水淬渣重金属浸出浓度低,环境安全性能优良,可以作为一种较为理想的吸附剂.     

恒电流库仑滴定法测定铬渣中的铬（Ⅵ）

铬渣样品以（１＋１０）磷酸溶液加热消解１．５ｈ,可得到完全澄清的消解液。采用恒电流库仓滴定法测定消解液中的Ｃｒ（Ⅵ）,测得值（１．６４％）与标样参考值（１．７％）接近,准确度高,相对标准偏差为０．９８％。适于铬渣中Ｃｒ（Ⅵ）的日常监测。     

Strength and workability of masonry mortars manufactured with ladle furnace slag

Ladle furnace basic slag (LFS) is a by-product of the steelmaking process. It has rarely been recovered in the past and is usually disposed of in landfill sites. Despite containing stable chemical substances of great quality, some of which are potentially hydraulic, its practical applications have been limited. This paper discusses the attractive option of using LFS in the manufacture of masonry mortars for use in the construction industry, which requires an analysis of the principal characteristics of such mortars, i.e. workability and mechanical strength. It reports on a comparative study, using standard commercial admixtures, between conventional masonry mortars and mortars manufactured with LFS as a partial replacement for sand and cement, the results of which imply considerable economic savings in sand and cement, improvements in the properties of the mortars and in overall sustainability, by avoiding disposal and conserving natural resources.     

铬渣污染场地修复技术研究进展

铬渣对中国地下水、地表水和土壤造成了严重污染,并对生态环境和人体健康构成了巨大威胁。开展对铬渣污染场地的修复工作已迫在眉睫。在分析铬污染特性的基础上,阐述了国内外最新铬污染场地修复技术研究动态,并概括分析了其不足与未来铬渣污染场地修复技术的发展趋势。     

铬渣湿法和干法解毒技术的应用对比

通过对国内典型铬渣处理的项目进行分析,并结合某铬渣污染治理工程实例,从反应机理、解毒工艺、工艺适应性、资源回收利用、设备选型、处理规模、场址选择、污染控制及安全生产和经济性方面对铬渣湿法解毒和干法解毒技术在实际应用中的选择进行对比,为该项目提出了更适合的解毒技术。     

气化炉渣的重金属浸出特性及化学形态分析

分别采用硫酸硝酸法、水平振荡法和醋酸缓冲溶液法制取气化炉渣的浸出液,考察了不同提取方式对浸出液中重金属质量浓度的影响。采用改进BCR连续提取法对气化炉渣中的重金属Cr,Zn,Cu,Pb,Ni,As,Cd的化学形态进行了分析。实验结果表明：煤气化工艺中的气化炉渣属第Ⅰ类一般工业固体废物;在3种提取方式中,醋酸缓冲溶液法的重金属浸出种类最多,且浸出量最大;Cd和Cr对环境具有较高的潜在危害性,Cu次之,Zn,Pb,Ni,As主要以残渣态形式存在,对环境的直接危害性较低。     

模拟氯化钠盐渣的高温处理

采用高温处理法对模拟氯化钠盐渣（简称盐渣）进行处理,研究了加热过程中气体有机物产生量随加热时间的变化规律以及加热温度对气体有机物产生量的影响,并分析了盐渣的高温处理效果。实验结果表明：含苯盐渣、含异丁醇盐渣、含氯苯盐渣、含二甲苯盐渣和混合盐渣在高于盐渣中所含有机物沸点30 ℃的条件下加热120 min,盐渣中的有机物去除率均大于99.99%;混合盐渣的加热温度越高,气体有机物的产生速率越快,相同时间内有机物的去除率也越大;盐渣中有机物的气化分离可分为3个阶段,初始阶段有机物气化速率较小,中间阶段气体有机物产生量迅速增加,最后阶段大部分有机物从盐渣中气化分离;盐渣中的有机物在高温气化时,会发生一定的化学反应,有微量的新物质生成。     

氢氧化钠-钢渣双碱法烧结烟气脱硫工艺

在鼓泡反应器中考察了氢氧化钠-钢渣双碱法烧结烟气脱硫的主要影响因素。结果表明,在温度为常温,钢渣反应时间为2 h,钢渣加入量为40 g,SO2进口浓度为2 400 mg/m3,钢渣粒径为200目以上,烟气流量为0.05 m3/h,循环液pH保持在7～8,Na+浓度为0.5 mol/L,循环液为500 mL的条件下,脱硫率可长时间保持在80%以上。同时,对钢渣-氢氧化钠双碱法烧结烟气脱硫机理进行了探讨。