Leaching Mechanism of Complicated Antimony-Lead Concentrate and Sulfur Formation in Slurry Electrolysis

Anodic reaction mechanism of complicated antimony-lead concentrate in slurry electrolysis was investigated by the anodic polarization curves determined under various conditions. The main reactions on the anode are the oxidations of FeCln^(2-n) . Though the oxidation of jamesonite particle on the anode can occur during the whole process, it is less. With the help of mineralogy studies and relevant tests, the leaching reaction mechanism of jameson[to and gudmundite during slurry electrolysis was ascertained. Because of the oxidation reaction of FeCl3 produced by antimony-lead concentrate itself, the non-oxidation complex acid dissolution of jameson[re, the oxidation complex acid dissolution of gudmundite, and the oxidation of air carried by stirring, the leaching ratio of antimony reaches about 35% when HCl-NH4Cl solution is used to leach antimony-lead concentrate directly. So when the theoretical electric quantity is given to oxidation of antimony in slurry electrolysis, all of antimony, lead and iron containing in antimony-lead concentrate, are leached. The formation of sulfur is through the directly redox reaction of Fe^3 and jameson[re. The S^2- in jamesonite is oxidized into S^0 , and forms the crystals of sulfur again on the spot. The redox reaction of Fe^3 and H2S formed by non-oxidative acid dissolution of jamesonite is less.     

Velocity Distribution of Slurry in Horizontal Pipe When Solid Particles Sliding

Based on the laws of momentum conservation and impulse in accelerating process, the distribution on speed of ununiform slurry flow in a horizontal pipe was studied. According to the momentum change of solid particles and conveying liquid of slurry flow during accelerating, and some effect factors, the relationship between the speed of solid particles and the speed of conveying liquid was obtained.When dealing with the friction between sliding solid particles and pipe, it is pivotal to reasonably distribute component of friction to each solid particle. The friction coefficient between solid particles was obtained by forces analysis and theoretic calculation, and can be used to calculate the friction force on every solid particle. The effect of friction on speed of ever), solid particle was investigated through the impulse law. The result is more accurate than that by using uniform friction on solid particles. It is completely new method to use above theory to get solid particles speed distribution, conveying liquid speed distribution and slurry speed distribution.     

微菱形织构表面旋转轴密封性能研究

综合考虑液膜空化及质量守恒边界条件,构建了轴面微菱形织构油封模型,通过数值计算获得膜压分布和微菱形孔结构参数对密封性能的影响关系。结果表明：微菱形孔所引起的动压效应可使膜压场产生变化,从而影响密封可靠性、润滑特性和泵汲效应;通过改变结构可控制泵吸方向、稳定液膜和减小摩擦。为提高稳定性和泵汲效应,并降低泄漏和磨损,选用半轴比γ=0.4~0.6、孔深h₁=1.5~4.5μm和微孔旋转角α=40°~50°轴面微菱形孔织构更为合理。     

食品源单增李斯特菌喹诺酮类抗生素耐药机制研究

以945株食品源单核细胞增生李斯特菌(Listeria monoocytogens,LM)作为研究对象,分析其对喹诺酮类抗生素耐药的分子机制。采用KB法筛选出喹诺酮类耐药的LM,利用PCR检测喹诺酮耐药决定区(quinolone resistance-determining region,QRDR)的基因突变以及质粒介导喹诺酮耐药(plasmid-mediated quinolone resistance,PMQR)基因的分布情况,结合最小抑菌浓度(MIC)值和外排泵抑制剂利血平分析其外排泵的作用,多位点序列分型(multilocus sequence typing, MLST)结合血清组对耐药菌株进行遗传多样性分析。结果表明:32株耐药菌株中gyrA、gyrB、parC与parE的QRDR均未发生氨基酸突变,且未检测到PMQR相关基因;而7株fepR基因发现新的氨基酸突变位点,其作用机制有待阐明;外排泵基因lde在耐药LM中皆有检出,78.1%(25/32)LM加入利血平后MIC值降低至原MIC的1/2以下,lde可能是导致LM对喹诺酮耐药的重要因素。血清组分析发现32株耐药菌株分属血清组I.1、I.2、II.1、II.2和III,MLST共分为10种ST型,其中ST87、ST9和ST8为优势株,具有一定的致病能力。结果表明,lde是LM产生喹诺酮耐药的重要因素,但LM潜在喹诺酮耐药分子机制仍有待阐明,同时其潜在的致病性应引起重视。     

特种车辆涡轮增压器内部流动特性分析

涡轮增压器是特种动力装备的重要动力部件,良好的密封是保证涡轮增压器正常工作的关键因素,而叶轮高速运转引发的压力不均则是泄漏的重要原因.基于流体力学分析方法建立有限元模型,研究了一种离心泵式密封结构的内部流场分析及流动特性,探讨了压气机端泄漏量、内部压力在不同转速和窄隙出口负压等工况下的变化规律,验证了该密封结构的油气密封性能.结果表明,受高速离心效应影响,该密封结构具备良好的防止压气机端漏油效果,高速运转时会产生漏气.研究结果为改进涡流增压器密封结构提供了参考依据.     

泵水力设计方法的研究现状

泵是流体输送系统的核心动力源,开展泵优化设计、实现节能降耗一直是流体机械领域的研究热点。文章回顾了基于一元、二元、三元流动理论进行水力设计的各种方法,总结了各个水力设计方法的优缺点;概括了近年来在叶轮、导叶、蜗壳水力设计方面的研究热点和主流方法,为今后泵设计方法的发展奠定了基础。以数值模拟结合三元流动理论和优化算法的设计方法已成为当前开展泵水力设计的主流手段,可以预期,随着计算机计算能力的进一步提高和优化算法的快速发展,泵的水力设计水平将会有大幅度提升并会促进泵行业的整体技术进步。     

改性化工污泥与煤的成浆性及燃烧性分析

选取两种方法对化工污泥进行改性并研究改性后的污泥添加量对污泥水煤浆(S-CWS)成浆性、流变性和燃烧性的影响,从而获得制备高浓度污泥水煤浆的工艺参数.结果表明:选用Na OH对污泥进行改性制备出的污泥水煤浆成浆性较好;改性污泥添加量在10%~20%,可以得到成浆性良好的污泥水煤浆;添加改性污泥的污泥水煤浆较普通水煤浆的燃烧性能增加.     

严寒地区某示范工程土壤源热泵系统综合评估

通过实时监测严寒地区某教学楼示范工程土壤源热泵系统运行的各项参数,从技术性、节能性、环保性及经济性各自不同的角度全面进行综合评估。为严寒地区土壤源热泵系统的高效运行提供参考。     

离心泵性能测定远程实验系统的开发与设计

开发了一套基于计算机网络的离心泵性能测定远程实验系统,介绍了该远程实验系统的总体结构、软件功能、运行方法及安全设计等。测试结果表明,该远程实验系统满足离心泵性能测定实验的教学目的,具有很强的现场感、操作简单等特点。     

梅梁湖泵站主水泵大修技术探讨

通过对无锡市梅梁湖泵站主水泵进行大修,系统总结了大修的准备、检查、安装工作,并对存在的问题提出了相关的建议。