应用于仲钨酸铵结晶过程中钨钼分离的高效方法

通过对大量仲钨酸铵(Ammonium Paratungstate,APT)结晶生产数据的总结,发现结晶料液(钨酸铵溶液)中氯离子浓度与APT晶体的钼含量之间存在明显的负相关关系,即氯离子具有在APT结晶过程中抑制Mo析出的作用。进一步研究还发现,对于特定组成的结晶料液,存在一对应的氯离子浓度阈值,在此阈值氯离子对料液中Mo析出的抑制作用达到最强。在此基础上,提出一种通过控制结晶料液氯离子浓度来实现APT结晶过程钨钼分离的高效、新型方法。通过这种方法,不但能够将APT的一次结晶率从原来的80%提高到96%,而且制得的APT产品具有晶体结构好,粒度均匀,纯度高(Mo含量不大于2×10-5)的优点。同时,对氯离子抑制钼析出的机理进行了探讨。     

Fenton 絮凝工艺去除废水中的有机物试验

为了研究废水中有机物的去除问题,针对某企业含有机物废水进行了对比试验,采用了Fenton 絮凝联合工艺去除废水中的COD（化学需氧量）和浊度,考察了初始pH值、H2O2投加量、H2O2与Fe2+投加物质的量比、反应时间、絮凝剂投加量以及絮凝剂投加时的pH值对COD以及浊度去除效果的影响。结果表明,采用最佳工艺参数组合后,浊度去除率和COD的去除率分别为99.32%和97.27%。     

Two-dimensional crystallization of Ca-ATPase by detergent removal

By using Bio-Beads as a detergent-removing agent, it has been possible to produce detergent-depleted two-dimensional crystals of purified Ca-ATPase. The crystallinity and morphology of these different crystals were analyzed by electron microscopy under different experimental conditions. A lipid-to-protein ratio below 0.4 w/w was required for crystal formation. The rate of detergent removal critically affected crystal morphology, and large multilamellar crystalline sheets or wide unilamellar tubes were generated upon slow or fast detergent removal, respectively. Electron crystallographic analysis indicated unit cell parameters of a = 159 A, b = 54 A, and gamma = 90 degrees for both types of crystals, and projection maps at 15-A resolution were consistent with Ca-ATPase molecules alternately facing the two sides of the membrane. Crystal formation was also affected by the protein conformation. Indeed, tubular and multilamellar crystals both required the presence of Ca2+; the presence of ADP gave rise to another type of packing within the unit cell (a = 86 A, b = 77 A, and gamma = 90 degrees), while maintaining a bipolar orientation of the molecules within the bilayer. All of the results are discussed in terms of nucleation and crystal growth, and a model of crystallogenesis is proposed that may be generally true for asymmetrical proteins with a large hydrophilic cytoplasmic domain.     

SPHC板带除鳞工艺实践与改善

基于热轧线的工况特点,从板带除鳞机理着手研究了氧化铁皮的去除工艺。结果表明,通过优化加热工艺和加热制度,SPHCCP生氧化铁皮压入的问题得到有效改善。     

湿法炼锌黄钾铁矾除铁中和剂的研究

研究了湿法炼锌黄钾铁矾渣除铁工艺的中和剂,分析了碳酸氢铵和焙砂作为沉矾中和剂的优缺点,指出用除去铁酸锌的焙砂作中和剂,可降低成本,减少渣含锌.     

焦化废水生物强化处理及工艺优化

焦化废水因其成分复杂、有机物难降解而饱受关注,随着《炼焦化工行业污染物排放标准》(GB 16171—2012)的实施,更严格的排放标准给各焦化企业都带来了挑战。原有系统出水只能符合旧标准,因而针对新标准的要求,对原有的焦化废水处理系统进行优化。生化段增加厌氧池、投加微生物菌剂进行生物强化,使生化段出水总氮(TN)由原来的40降低至10mg/L;深度处理应用臭氧氧化技术,使化学需氧量(COD)降低至30mg/L,优化效果显著,达到了预期目标,为国内同类型的焦化废水处理流程提供了一定的参考和借鉴意义。     

硫酸锌溶液冷却结晶除钙镁生产实践

对几种不同的除钙镁工艺进行了对比分析,研究了冷却沉降法除硫酸锌溶液中的Ca、Mg,实验表明,冷却沉降法是一种节能、高效的工艺方案,控制温度25℃、pH=3.8～4.5、晶种加入量4 g/L、沉降时间100 min,可获得较好的工艺指标。     

化学沉淀法从氨氮废水中回收磷酸铵镁

在模拟氨氮废水中进行磷酸铵镁(MAP)沉淀实验,研究回收MAP的适宜条件.结果表明:在pH值8.0~11.0之间时生成的沉淀主要成分为MAP;当pH值为10.0,离子配比n(NH₄⁺):n(Mg²⁺):n(PO₄^3-)控制在1:1.4:1时得到的晶体纯度较高,沉淀量可达3.14g·L^-1,此时氨氮去除率为91.5%.分析表明回收MAP可以大幅度降低化学沉淀法的成本,有利于该方法的实际应用.     

高磷鲕状铁矿酸浸脱磷

研究了酸浸处理高磷铁矿脱磷及其影响因素.实验用鄂西鲕状高磷矿Fe的质量分数为51.7%,P的质量分数约0.5%,S的质量分数为0.34%.通过硫酸浸出,浸出矿中磷的质量分数降低至0.07%左右,而铁损只有0.18%,S的质量分数为0.35%,满足钢铁生产的要求.通过扫描电镜观察和能谱分析表征了高磷矿中磷的脱除,在实验酸度下能明显看出磷灰石溶解,而铁相基本不反应,并得到了热力学计算证明.实验确定了最佳的酸浸条件:浸出时间1 h,液固比100mL:8 g,酸度0.2 mol·L^-1,振荡频率150 Hz.通过微波加热预处理,高磷铁矿中产生微裂纹,增加了矿石的比表面积,但是这并没有明显促进酸浸脱磷的进行.通过补酸的方式循环利用酸浸液处理高磷铁矿能得到较好的脱磷效果,脱磷率稳定在80%,能有效减少酸耗、保护环境.     

硫酸铵、镁、锰复盐结晶动力学研究

在硫酸铵、镁、锰复盐体系中,当Mn2+、Mg2+、NH4+初始浓度分别为28、20、30 g/L,蒸发瓶转速为30 r/min,结晶温度为298、308、318、328 K时,研究了铵、镁、锰复盐体系的悬浮密度、晶体粒度、晶体粒数密度、晶体结晶动力学.结果表明:在复盐结晶过程中,当结晶时间为4500 s,结晶温度为32...     

电絮凝用于焦化废水脱色的研究

采用了连续电絮凝工艺对焦化废水进行深度处理,考察了电流密度、溶液pH值、电解质密度和水力停留时间等工艺参数对脱色效率的影响。UV-Vis谱图证实了电絮凝能有效地对有机物进行降解和脱色。结果表明,电絮凝工艺对焦化废水脱色效果明显,当电流密度为30 mA/cm2,pH值为8.0,极板距为1.0 cm,支持电解质浓度为0.5 g/L,在25℃下反应80 min后脱色效率达91%以上。     

生化处理技术治理焦化废水的实践

采用HSB＋A／O生化处理技术改造南昌钢铁有限责任公司焦化污水处理系统，该系统投资少，运行成本低，外排废水达到GB13456—92要求。     

生化处理技术治理焦化废水的实践

采用HSB+A/O生化处理技术改造南昌钢铁有限责任公司焦化污水处理系统,该系统投资少,运行成本低,外排废水达到GB13456-92要求。     

硫酸铵焙烧红土镍矿工艺优化

本文采用硫酸铵焙烧-水浸工艺,将红土镍矿与硫酸铵混合焙烧,研究了焙烧温度、焙烧时间、物料配比和矿粉粒度对镍、镁、铝和铁提取率的影响.采用正交实验优化工艺条件,得到影响焙烧效果的各因素顺序为:物料配比、焙烧时间、焙烧温度、矿粉粒度.优化工艺条件为:焙烧温度450℃,焙烧时间120min,物料配比2∶1,矿粉粒度小于80μm,镍、镁和铝提取率大于98%,铁提取率大于94%.研究了焙烧过程镍、镁、铝和铁与硫酸铵反应过程的动力学.镍、镁、铝和铁的反应速率均符合未反应收缩核模型,表观活化能分别为19.93 k J·mol^-1、18.96 k J·mol^-1、17.86 k J·mol^-1和20.83 k J·mol^-1.     

Prediction of decarburisation process along with hydrogen and nitrogen removal by mathematical modelling of RH degassing process

The decarburisation process is studied with the help of mathematical modelling of RH degasser with reaction interface area approach, considering multi-component mixed phase mass transport theory. An algorithm is developed by considering Ar gas, bath surface and CO gas bubbles as the reaction sites for decarburisation process. On the basis of this, the model is developed using MATLAB. The model is tested with five sets of data which are obtained from JSW Steel Plant Ltd. The results obtained from the model have been compared with the industrial data as well as the data obtained from literature survey. It is shown that the nitrogen and hydrogen removal are triggered more for higher CO evolution rate. The relations between carbon removal and factors like area of interface, time and vacuum pressure are proposed.     

水雾化制备Fe-Si-B-C非晶软磁粉末及其晶化过程的研究

采用水雾化方法制备了Fe-Si-B-C四元非晶合金粉末。研究了粉末的粒度分布、相结构、微观形貌、热稳定性以及基本软磁性能,并通过Kissinger峰移法计算了其晶化时所需的激活能。结果表明,通过水雾化方法制备的Fe-Si-B-C四元软磁粉末的粒度分布合理;粒径小于38μm的粉末为完全非晶结构,且粉末表面光滑,内部成分均匀;非晶粉末的初始结晶温度为542.15℃,且升温过程中存在2个晶化放热峰;2个晶化反应对应的晶化激活能分别为463.92 k J/mol和910.21 k J/mol;粉末的饱和磁感应强度和矫顽力分别为1.08 T和111.4 A/m。     

碱性离子交换制取钼酸铵溶液研究

研究了高杂钼酸钠溶液在某强碱性CO_3~(2-)型树脂上的吸附解吸情况,考察了溶液中的P、Si、As、V等杂质在离子交换中的行为,根据实验得出Mo吸附解吸的最佳条件。结果表明,树脂对P、Si、As的去除效果良好,除杂率在96%以上。     

尿素、碳酸氢铵/添加剂同时脱硫脱硝试验研究

在鼓泡反应装置上进行了尿素、碳酸氢铵/三乙醇胺溶液同时脱硫脱硝的试验研究,比较尿素和碳酸氢铵的脱硫脱硝性能,试验分别对液位、吸收剂组成以及SO2体积分数等参数对脱硝效率的影响规律进行了研究.结果表明:液位、吸收液中尿素/碳酸氢铵的比例及SO2入口浓度对NOx的脱除效率均有重要的影响,液位在459 mm时2种吸收液的脱硝效率最高;增加多元溶剂中碳酸氢铵质量浓度不利于NOx的脱除,而5%尿素、5%碳酸氢铵/三乙醇胺(0.015%)多元溶剂的脱硝效率仅比10%的尿素/三乙醇胺(0.015%)溶液低约9%,脱硝效率仍可达63%以上,脱硫效率高达97%以上,但其吸收剂成本比后者低近30%;SO2的存在起到了协同促进作用,反应中生成的亚硫酸根离子对NOx具有还原作用,使得2种吸收液的脱硝效率均提高了约3%.     

Defining the Paragoethite process for iron removal in zinc hydrometallurgy

The previously ambiguous Paragoethite process and residue are defined, and the importance of a fundamental understanding of iron-phase precipitation in hydrometallurgical processing is demonstrated. A review of iron removal in zinc hydrometallurgy and in the Paragoethite process extends previous Paragoethite process studies and provides a brief overview of the iron-phase ferrihydrite, including recent experimental evidence. It is demonstrated that commonly referred to ‘amorphous iron phases’ are likely to be the nanoscale minerals ferrihydrite and/or schwertmannite. In the case of the Paragoethite process, 6-line ferrihydrite constitutes around 40–50% of the residue. Through further characterization and continuous crystallization studies the remaining precipitated components of Paragoethite process residues were found to be solid-solution jarosite phases (containing Pb), silica (containing iron), and at lower pH, poorly crystalline goethite. By using continuous crystallization, the effect of pH on phase formation and on the properties of the residue is documented; emphasizing filterability constraints and the role and reaction of residual calcine. Such studies have permitted a more fundamental understanding of the simultaneous precipitation of ferrihydrite, goethite, and jarosite from acidic hydrometallurgical liquors, including the interplay in this kinetically controlled system, where ferrihydrite is favoured. Reasons for poor filterability are suggested, indicating that the rate of crystallization, and hence, supersaturation, governs phase formation and residue properties. The aggregation-dominated and kinetically favoured nanoscale ferrihydrite particles dictate the physical properties of the residue.