捕收剂在硫化矿物表面吸附机理的研究进展

综述了药剂与硫化矿表面吸附作用机理的理论研究,总结了现代表面测试技术在硫化矿表面吸附作用机理研究中的应用前景．表面测试技术在选矿中的应用,使矿物与药剂的吸附机理研究更加深入,也促进了浮选理论和工艺技术的持续发展和不断完善．     

Bioelectrochemical sulfate reduction enhanced nitrogen removal from industrial wastewater containing ammonia and sulfate

Low organic carbon-to-nitrogen ratio and existing sulfate (SO₄²⁻) in industrial wastewater limited nitrogen removal. Coupling SO₄²⁻ reduction with sulfide autotrophic denitrification provides a novel strategy. Herein, bioelectrochemical sulfate reduction was coupled with heterotrophic sulfate reduction to drive sulfide autotrophic denitrification. In this coupled system, total nitrogen (TN) removal efficiency was increased from ~25% to ~85% by inputting −45 mA electricity. With the help of supplying electrons to denitrification through SO₄²⁻ reduction, coulomb efficiency was improved to 61.5%. Also, bioelectrochemical sulfate reduction could improve sulfur recovery and thus increase TN removal efficiency. Furthermore, through tuning turnover numbers of SO₄²⁻, high TN removal efficiency can be obtained at various concentrations of SO₄²⁻. Moreover, main functional bacteria in this system were identified. Finally, ~75% TN removal efficiency was achieved with real wastewater in this system. Overall, this work offered a new approach for efficient nitrogen removal from industrial wastewater containing SO₄²⁻.     

模拟水中硫离子对不锈钢钝化膜破坏作用的光电化学研究

采用光电化学方法研究了模拟冷却水中硫离子对不锈钢钝化膜的破坏作用.结果表明,不锈钢钝化膜显示n-型光响应,最大吸收峰出现在310 nm处.不锈钢钝化膜在电位约-0.35 V开始出现光电流,随电位升高,光电流增大.钝化膜禁带宽度Eg随电位的升高而减小,并逐渐向铁氧化物的Eg靠近.模拟冷却水中加入硫离子使不锈钢钝化膜的光电流增大,Eg减小.硫离子的浓度越大,测得的光电流越大,而Eg越小,这可归因于钝化膜膜电阻的降低及钝化膜中氧化铬含量的减少.     

Copper hydrometallurgy-current status,preliminary economics,future direction and positioning versus smelting

The heap leaching of oxide copper ores with copper cathode recovery by solvent extraction and electrowinning is now well established as a low-cost method of copper recovery. This technology has recently been applied successfully to mixed oxide and chalcocite ores, notably in Chile at Cerro Colorado, Quebrada Blanca and Zaldivar.Currently, there are significant development efforts underway to try to extend heap leaching to chalcopyrite ores.The success of heap leaching/SX/EW has also led to a revival in the development of hydrometallurgical processes to recover copper from chalcopyrite and other copper concentrates. The current status of copper hydrometallurgy is reviewed and the most commercially attractive potential applications are explored. The advantages and disadvantages of the hydrometallurgical treatment of chalcopyrite concentrates and its preliminary economics are compared with those for the current best practices in copper smelting and refining.     

Defect structure and chemical diffusion in nickel sulfide β-Ni3S2

The chemical composition, defect structure, and diffusion in nickel sulfide -Ni₃S₂ have been investigated in H₂S-H₂ mixtures containing between 1 and 65% H₂S between 560 and 700°C. Gravimetric, density, and X-ray studies were carried out. In the thermodynamically stable compound the ratio of Ni/S varied between 1.3 and 1.75. The X-ray examination showed a step change in the lattice parameter at the Ni/S ratio 1.4. A linear dependence of the density values (between 5.5 and 6.2 g/cm³) on the composition was observed. On the basis of the chemical composition and density measurements the number of nickel and sulfur atoms in 1 cm³ were determined. It has been shown that the Ni₃S₂ phase is defected in both anion and cation sublattices and that its chemical formula may be described as follows: Ni_3±yS_2x, where y 2x. It has been found that in the mixture containing 10% H₂S the process of defect formation is determined by their diffusion in the sulfide. The temperature dependence of the diffusion coefficient is described by the equation D = 13.15 exp(-30,000/RT) cm²/sec. No dependence of D on the sulfur partial pressure was observed, but this may be due to the relatively large uncertainties in the measurement of the diffusion coefficients.     

Q235B 热轧H型钢拉伸试验分层断口的显微分析

Q2 35B热轧H型钢拉伸试验后出现分层断口。用扫描电镜进行了显微观察 ,发现分层现象与试样中超长的带状组织密切相关。用能谱仪对断口分层处和超长铁素体带上的夹杂物进行了成分分析 ,证实都是硫化物。试样拉伸时在铁素体带上密集分布的硫化物处产生大量微裂纹 ,同时超长铁素体带的变形又受到阻碍 ,导致该处在试样拉断之前裂纹已经贯通 ,最终在断口上形成分层。因此 ,拉伸试验断口出现分层的原因是试样中存在密集分布的硫化物和超长的带状组织。     

Fe50Mo在硫蒸气中的高温硫化

应用TGA、XRD、SEM/WDS技术研究了Fe50Mo合金在1kPa,700～900℃的硫蒸气中的高温硫化行为.发现在700℃时硫化遵从抛物线规律,800和900℃时则变为线性规律.Fe50Mo的硫化速度常数比纯Fe的低3～4个数量级,比Fe20Mo和Fe40Mo的抗硫化性能有了显著提高.热处理对合金硫化行为无显著影响.最初只出现FeS单一硫化产物层,合金中发生μ相晶界处α-Fe相的选择硫化.长时间硫化后,FeS层下出现MoS2内层,其晶体片层垂直于样品表面,有助于扩散传质.但MoS2层致密、微观缺陷少     

室温盐液渗硫

介绍了室温盐液渗硫新工艺，采用SBR系列硫化液对淬火45钢表面进行了室温硫化处理，借助SEM、EDAX和XRD研究了渗硫层的结构和形貌，分析了渗硫层显微硬度的分布。结果表明，室浊盐液渗硫层呈片状结构，主要由FeS相组成，其硬度仅为63HV；适当调整硫化盐液浓度将有利于提高渗速，一般经（0.5-1)h处理可获得10μm左右厚度的渗硫层。     

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 文章利用中频感应炉炼制2种锰含量不同的硫化物自润滑合金，通过SEM观察断口并结合组织分析，研究合金中的硫化物形成以及合金的断裂行为。结果表明，硫化物处于韧性较差的珠光体中导致形成脆性解理断口，而硫化物处于韧性较好的铁素体中则形成韧性的韧窝断口。锰含量较低时硫化物以FeS为主，且为复相组织；含坚硬的V、Nb、Ti小颗粒化合物，易脱落；锰含量较高时硫化物以MnS为主。     

不同金属硫化物从钨酸盐溶液中除钼的效果

针对钨冶炼过程中钨钼分离这一关键问题,研究了利用CuS,CoS,NiS,PbS,FeS,ZnS和HgS等金属硫化物从钨酸盐溶液中除钼的效果.对含钼的Na2WO4或(NH4)2WO4溶液用Na2S或(NH4)2S 进行硫化处理,使其中的MoO2-4转化为MoS2-4,然后加入上述金属硫化物进行除钼.结果表明,CuS,CoS和NiS在Na2WO4或(NH4)2WO4溶液中均具有良好的除钼效果,综合考虑经济、环保等因素,认为CuS是最经济合理的钨钼分离新试剂.考察了试剂用量、反应温度和溶液pH值对除钼效果的影响,并获得了最佳除钼工艺条件,即在CuS试剂用量为理论量的3～4倍、室温下搅拌反应1h的条件下,可使溶液中的Mo从0.6～0.77g/L降至0.007～0.02g/L,除钼率达96.0%～98.5%,整个除钼过程中钨的回收率达99.75%以上.