地铁电气火灾中机械方面影响因子系统动力学仿真分析

在揭示地铁电气火灾机械方面影响因子的基础之上,运用系统动力学理论与分析 方法,构建地铁电气火灾机械方面影响因子仿真模型,对各影响因子进行动态预测。通 过对比分析不同因子的安全投入增长率对机械方面安全水平的影响大小,论证安全投入 与系统安全水平的相互关系,总结出最为有效地投资方案。结果为地铁安全管理工作提 供一定的理论指导,有助于提高地铁安全管理决策的科学性和预见性。     

特殊地质条件下深钻孔排渣技术及应用

针对特殊地质结构及远距离下行钻孔孔内残留钻屑量大,排渣困难,钻孔有效利用率低,抽采效果不理想等不利影响,结合现有悬浮剂资料,配置一定密度的悬浮液并进行排渣技术试验。试验结果表明,悬浮液排渣能够排出钻孔中残留的钻屑,清洗钻孔,避免钻屑填埋煤层段,延长钻孔有效深度,提高瓦斯抽采效果,浅钻孔瓦斯抽采纯量提高27%,抽采浓度提高8%,深钻孔瓦斯抽采纯量提高110%,抽采浓度提高340%。为特殊地质结构下深钻孔排渣工作提供一定的参考依据。     

对硝基苯酚和重金属在高炉水淬渣上的竞争吸附研究

以高炉水淬渣（WBFS）为吸附剂,对水体中的对硝基苯酚（p-NP）和重金属进行单一吸附和竞争吸附的研究,从吸附等温线、吸附动力学和热力学等方面分析其吸附特性和机理.结果表明：相对于p-NP,重金属离子在竞争条件下居优势地位,重金属离子对p-NP的竞争吸附作用依次为Cu²⁺ >Cd²⁺ >Zn²⁺.高炉水淬渣对p-NP的吸附符合Freundlich模型,而重金属离子的吸附与Langmuir吸附模型拟合较好,D-R模型计算的p-NP在各系统中吸附能量分别为-7.53、-7.07、-7.96以及-7.86kJ/mol,表明高炉水淬渣吸附p-NP的过程中以物理吸附为主,而重金属离子则以化学吸附和离子交换为主.动力学曲线显示在二元体系下p-NP的吸附速率下降,吸附达到平衡的时间延长,而竞争组分的存在对Cu²⁺、Cd²⁺、Zn²⁺达到平衡的时间基本无影响.高炉水淬渣对Cu²⁺、Cd²⁺、Zn²⁺表现出更高的亲和力和选择性.无论是单一吸附还是竞争吸附,p-NP和Cu²⁺、Cd²⁺、Zn²⁺均符合伪二级动力学方程.△G值随着温度的升高而逐渐降低,说明高炉水淬渣对p-NP和Cu²⁺、Cd²⁺、Zn²⁺吸附的自发性与温度成正比,属于吸热熵增的过程.     

BSSF滚筒法钢渣处理技术发展现况研究

介绍了BSSF滚筒法渣处理技术的原理和发展现状,通过对主体设备的不断优化完善及工艺系统的再次开发,对钢渣黏度适应性增强,钢渣处理率从30%提高到85%,系统运行稳定,为钢渣资源化利用提供了良好的条件,符合当今社会对环保及固废资源循环利用的需求。     

Comparison of sample digestion procedures for the determination of trace elements in antarctic krill by GF‐AAS

Two independent digestion procedures for Antarctic krill samples were compared. Dry ashing (DA) and microwave (MW) acid‐assisted digestion were tested for decomposing the samples to determine essential (Cu, Fe, Cr) and toxic elements (Cd, Pb) by graphite furnace‐atomic absorption spectrometry (GF‐AAS). A mixture of HNO₃ and H₂O₂ as digesting agent was used in the microwave procedure. For the dry ashing digestion, the organic matter was oxidated at 480°C in an open system. Both digestion methods were compared in terms of accuracy and applied to the analysis of a certified reference material: MURST‐ISS‐A2 (Antarctic krill).

The detection limits for the five elements analysed ranged from 3 to 150 ng g^‐1. Both digestion procedures are suitable for the decomposition of krill samples. However, dry ashing is not recommended to determine Pb and Cd because losses can occur.     

Scalp hair metal analysis in the assessment of the occupational exposure of arc welders

Eleven metals (Ca, Mg, Fe, Zn, Cu, Mn, Cd, Co, Cr, Ni and Pb) were estimated in hair samples of metal arc welders and a control group with the same socioeconomic background. Nitric acid–perchloric acid wet digestion procedure was adopted for the estimation of endogenous metal contents by ICP-AE technique. The study exhibited the following increasing order of the metal concentrations: Cd??1, dry weight, respectively. On average, the levels of Mn, Ni, Pb and Fe were found to be 1.5–2.4 times higher in the hair of welders compared with controls. Besides age and exposure which were strongly correlated, Cu–Mg, Mn–Mg, Ca–Co and Cd–Zn also showed significantly positive correlations. The identification of metal sources, done by cluster and principal component analyses, revealed four factors: age and exposure; Cu, Mg, Mn and Fe; Ca and Co; Cd, Zn, Ni and Pb. High levels of Fe were found to have a depleting impact on Co levels. The arc welders were feared to accumulate heavy metals in their bodies due to long-term endogenous exposure.     

我国钢铁行业二恶英污染防治技术研究

钢铁行业(烧结和电炉炼钢)是我国二恶英减排优先重点控制的行业之一。简要介绍了二恶英的理化性质、危害性、生成机理及必备条件,结合烧结过程和电炉炼钢过程二恶英的产生成因,从工艺过程污染预防技术和污染治理技术两方面探讨二恶英减排途径。     

变频器在高炉出铁场除尘系统中应用的优势

介绍了传统的节能调速方式及变频器调速的节能原理,并结合工程实例综合分析了高炉出铁场除尘系统采用变频器调速在节能和设备运行等方面的优势。     

袋式除尘器在70吨Consteel电炉除尘改造上的应用

介绍了低压脉冲滤袋除尘器净化70 t Consteel电炉烟气的工艺过程、运行实际参数以及设计过程中的一些经验。     

电石渣处理洗煤废水的效果及作用机理研究

为了防止洗煤废水的污染并使之处理后能够回用,开展了电石渣-PAM(聚丙烯酰胺)处理洗煤废水小试实验研究以及实际工程应用的研究,并通过实验与理论分析,对电石渣处理洗煤废水的作用机理进行研究.实验研究结果以及实际工程应用效果表明,采用电石渣-PAM混凝沉淀法处理洗煤废水具有较好的处理效果,处理后煤泥水的各项指标均能达到国家排放标准,且能满足洗煤工艺的用水要求.实验研究与理论分析结果表明,电石渣对洗煤废水的混凝作用不是补给了OH-,而是提供了大量的Ca2 ,Ca2 通过压缩双电层,破坏了煤泥颗粒的稳定性,从而使煤泥颗粒发生凝聚,OH-和Ca(OH)2对洗煤废水的混凝不直接起作用.