粗硫酸镍生产工艺的优化

介绍了贵冶电解车间冷冻结晶法生产粗硫酸镍项目的生产运行情况,以及为扩大产量在工艺流程、操作方式、挖掘设备潜能等各方面所作的改进优化工作。     

甘蔗糖蜜酒精废液的二相厌氧-好氧处理

硫酸盐还原和产甲烷分别在两相UASB反应器中进行:硫酸盐还原主要在一相UASB中完成,SO42-去除率在85%以上;产甲烷主要在二相UASB中完成,沼气产率为0.11~0.13 L/g COD.当二相UASB中COD负荷提高到30 kg/(m3.d)时,COD去除率达到65%~77%,出水COD浓度也会明显提高.碱度不足会影响SBR的硝化效果,当补充碱度后,出水氨氮多在10 mg/L以下.     

Reaction mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust

Abstract

The experiments in this paper were performed to research the mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust. The reduction potential of zinc during cementation was determined to investigate the morphology of products. Residues after the cementation process from zinc sulphate solution were analyzed by SEM and EPMA to investigate the morphology of products. Different temperature will cause different structure of particles. The reaction mechanism of cobalt removal by zinc dust is thought to be as follows: first, the Co2+ forms Co–Zn alloy with zinc particles, and the reaction reaches equilibrium quickly; second, the Co–Zn alloy continues reacting to Co with Co2+, which is the control process of the whole reaction.     

Performance of plate heat exchangers during calcium sulphate fouling — investigation with an in-line filter

The uncertainty about the fouling behaviour is one of the main reasons why plate and frame heat exchangers are not more widely installed in the chemical process industry and in power generating facilities. In the present investigation, the deposition of calcium sulphate in two different plate heat exchanger geometries was investigated. The deposition process was deliberately focused on crystallisation fouling through the installation of an in-line filter and the mode of preparation of the test solution. The investigated operating parameters were solution concentration, flow velocity, and bulk and surface temperatures. The heat exchangers were opened after each experiment to record the appearance and distribution of the deposits. The key result of this investigation is the strong correlation between the plate design and the tendency for deposit formation.     

季铵树脂上硫酸铀酰络离子的红外光谱研究

本文用红外光谱研究了季铵树脂吸附的硫酸铀酰络合物。树脂吸附UO_2(SO_4)_2~(2-)时,UO_2~(2+)的γ_3峰值为918cm~(-1),吸附UO_β(SO_4)_3~(4-)时,该峰值为910cm~(-1)。树脂在组成接近铀水冶条件的吸附液中吸附平衡后,吸附n值为2.5—2.7的UO_2(SO_4)_n~(2-2n),其UO_2~(2+)的γ_3峰与树脂的季铵峰合并于900cm~(-1);该树脂在KBr压片中会发生转换反应,使硫酸铀酰络离子转成UO_2(SO_4)_2~(2-)和SO_4~(2-)。还利用红外光谱定量测定反应终了的自由硫酸根量,在化学当量法求得的树脂吸附铀量及SO_4~(2-)量基础上,计算了n值。     

微量元素对镀锌层微观结构的影响

研究了硫酸盐镀锌液中常见金属微量元素离子Pb^2 ,Cu^2 ,In^ ,Fe^2 对沉积层的外观形貌，显微组织，结晶择优取向和耐蚀性的影响，研究表明，不同的要质对镀层的外观，显微组织以及晶面的择优取向的影响不同，铅离了孤引入降低了镀层的外观质量和（002）晶面的强度，镀离子的引入使镀层的外观质量和（002）昌面的强度均得到提高，起到了无机光亮剂的作用。     

精炼镁渣制光卤石和硫酸镁工艺研究

介绍了用精炼镁渣制取光卤石和硫酸镁的工艺过程,探讨了制备的工艺条件及有关影响因素。     

The effect of sodium sulphate on the hydrogen reduction process of nickel laterite ore

A series of nickel laterite ores with different calculated amounts of anhydrous sodium sulphate were prepared by physical blending or sodium sulphate solution impregnation. The reduction of the prepared nickel laterite ore by H₂ was carried out in a fluidised-bed reactor with provisions for temperature and agitation control, and the magnetic separation of the reduced ore was performed using a Davis tube magnetic separator. The mineralogical properties of the raw laterite ore, reduced ore and magnetic concentrate were characterised using ICP, TG–DSC, N₂ adsorption, X-ray diffraction and optical microscopy. The catalytic activity of sodium sulphate was also studied by using Hydrogen temperature-programed reduction. The experimental results indicate that Na₂SO₄ could overcome the kinetic problems faced by the laterite ore and that it exhibited noticeable catalytic activity only if the temperature reached at least 750 °C. This high temperature accelerated the crystal phase transition of the silicate minerals and increased the utilisation of H₂. In comparing the results from the two different methods for adding Na₂SO₄, the nickel content and recovery of the magnetic concentrate were increased by using the impregnation method rather than the physical blending method and the increasing amount of sodium sulphate assisted in the further beneficiation of nickel. The partial pressure of H₂ and the reducing time also affected the reduction process of the iron oxides. The results of the microscopic study indicated that the formation of a Fe–S solid solution, which was derived from the SO₂ sulphide reduction of FeO, was conducive to mass transfer and accelerated the coalescence of metallic ferronickel particles. For the nickel laterite ore, under the synergistic effect of sodium sulphate and hydrogen, a nickel content and nickel recovery of 6.38% and 91.07% were obtained, respectively, with high product selectivity.     

The effects of LiOH and NaOH on the carbonation of SrSO4 by dry high-energy milling

In this work, the effects of alkaline hydroxides (NaOH and LiOH) on the direct mechanochemical carbonation using dry high-energy milling of celestine (SrSO₄) under CO₂ atmosphere was investigated with X-ray diffraction (XRD), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and carbon analyses. It was observed that SrSO₄ was not directly carbonated by dry high-energy milling under CO₂ atmosphere without LiOH or NaOH additives. Direct mechanochemical SrCO₃ formation was observed during milling of the SrSO₄ and NaOH mixture under CO₂ atmosphere, and it was shown that a minimum 50% of the initial SrSO₄ was mechanochemically carbonated in the presence of NaOH and CO₂ gas. LiOH does not stimulate the direct carbonation. However, it was observed that washing of the milled mixture with water resulted in strontium carbonate (SrCO₃) formation because of the enhanced dissolution of Li₂CO₃ and SrSO₄, promoted by the activation effect of high-energy milling. Depending on the alkaline hydroxide used during the milling, strontium carbonates with different space group settings were formed, which have different (split or single) main carbonate absorption bands.     

椰子油乙氧基化物与阴离子表面活性剂协同效应研究

摘要：对椰子油乙氧基化物-30EO（COE-30）与直链烷基苯磺酸（LAS）、脂肪醇聚氧乙烯醚硫酸钠（AES-2）及脂肪醇聚氧乙烯醚羧酸钠（AEC-5）复配的二元体系进行研究,运用非理想溶液理论计算混合胶束和混合吸附层的组成及二者在混合胶束和混合吸附层中协同作用参数。结果表明,复配体系在混合胶束和混合吸附层显示出较强的协同作用,混合胶束中作用参数|βm|= 2~6,混合吸附层中作用参数|βσ|= 2~6。三个复配体系在形成胶束能力和降低表面张力效率方面存在协同增效作用,同时COE-30/AES-2和COE-30/AEC-5体系在降低表面张力能力方面也存在协同增效作用。