石煤空白焙烧过程热力学分析

从热力学上对石煤空白焙烧过程中发生的相关氧化反应进行了分析.有机碳、黄铁矿及钒的氧化反应,在热力学上都可自发进行,有机质和黄铁矿比钒更容易氧化.有机碳和黄铁矿的存在,对钒的氧化有阻碍作用,若预先脱碳或脱除黄铁矿,则有利于钒的氧化.     

Kinetics of nickel leaching from roasting-dissolving residue of spent catalyst with sulfuric acid

Sulfuric acid leaching process was applied to extract nickel from roasting-dissolving residue of a spent catalyst, the effect of different parameters on nickel extraction was investigated by leaching experiments, and the leaching kinetics of nickel was analyzed. The experimental results indicate that the effects of particle size and sulfuric acid concentration on the nickel extraction are remarkable; the effect of reaction temperature is mild; while the effect of stirring speed in the range of 400–1 200 r/min is negligible. Decreasing particle size or increasing sulfuric acid concentration and reaction temperature, the nickel extraction efficiency is improved. 93.5% of nickel in residue is extracted under suitable leaching conditions, including particle size (0.074–0.100) mm, sulfuric acid concentration 30% (mass fraction), temperature 80 °C, reaction time 180 min, mass ratio of liquid to solid 10 and stirring speed 800 r/min. The leaching kinetics analyses shows that the reaction rate of leaching process is controlled by diffusion through the product layer, and the calculated activation energy of 15.8 kJ/mol is characteristic for a diffusion controlled process. Foundation item: Project (50574101) supported by the National Natural Science Foundation of China; Project (2003UDBEA00C020) supported by the Collaborative Project of School and Province of Yunnan Province, China     

石英与蛇纹石异相凝聚及其对黄铁矿浮选的影响

通过单矿物和人工混合矿的浮选试验、Zeta电位测试、吸附量测试,研究了蛇纹石和石英异相凝聚的机理,以及对黄铁矿浮选的影响,以进一步探索多种矿物的体系中,蛇纹石对硫化矿物浮选影响的主要原因。结果表明:通过添加石英,可以恢复黄铁矿对捕收剂的吸附量,减弱蛇纹石的不良影响,不同粒级的石英与蛇纹石的异相凝聚作用强弱不同,粒级越细的石英,与蛇纹石的异相凝聚作用越强。     

New technique of comprehensive utilization of spent Al2O3 -based catalyst

A new technology was developed to recover multiple valuable elements from the spent Al2O3-based catalyst by X-ray phase analysis and exploratory experiments. The experimental results show that in the condition of roasting temperature of 750 ℃ and roasting time of 30 min, molar ratio of Na2O to Al2O3 of 1.2, the leaching rates of alumina, vanadium and molybdenum in the spent catalyst are 97.2%, 95.8% and 98.9%, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by precipitators A and B, and the precipitation rates of vanadium and molybdenum are 94. 8% and 92. 6%. Al（OH）3 was prepared from sodium aluminate solution in the carbonation decomposition process, and the purity of Al2O3 is 99. 9% after calcination, the recovery of alumina reaches 90. 6% in the whole process; the Ni-Co concentrate was leached by sulfuric acid, a nickel recovery of 98. 2% and cobalt recovery over 98.5% can be obtained under the experimental condition of 30% H2SO4, 80 ℃, reaction time 4 h, mass ratio of liquid to solid 8, stirring rate 800 r/min.     

铝土矿浮选尾矿强化沉降试验研究

针对河南某铝土矿沉降困难的问题,以该浮选尾矿为研究对象进行静态沉降试验,通过单因素试验和正交试验考察了pH、尾矿矿浆浓度、絮凝剂种类及用量等条件对尾矿沉降行为的影响规律,并研究了强化尾矿沉降的措施。静态沉降试验结果表明:尾矿中物质表面所带电荷和颗粒粒径是导致尾矿沉降速度低的主要原因,调节pH可强化尾矿的沉降;分子量为800万的阴离子型聚丙烯酰胺(以下简称PAM)能显著提高尾矿沉降速率;pH、PAM单耗与PAM配制浓度这3个因素中,pH对尾矿沉降速率的影响最显著,PAM单耗的影响次之,PAM配制浓度的影响相对较弱;在给料浓度为8%、pH=7.05、PAM单耗为200 g/t、PAM配制浓度为0.15%时,能得到良好的沉降指标,平均沉降速率为5.58 mm/min,优于强化沉降前的尾矿沉降速度0.35 mm/min。     

一水硬铝石(α-AlOOH)及其(010)表面的密度泛函研究

采用基于密度泛函-赝势的量子化学方法研究了一水硬铝石(α-AlOOH)晶体及其(010)表面的原子和电子结构.研究表明: GGA-PBE几何优化得到的晶体结构参数与实验测定数据相符; 通过体相原子间重叠布局分析确定了α-AlOOH(010)表面最容易解理的位置; 通过一系列测试计算选择原子层数为4, 真空层厚度为7.5的slab模型模拟α-AlOOH(010)表面, 结果表明表面原子发生弛豫, 且驰豫表面的表面能为0.491J/m2; 根据表面态密度分析、表面原子排布情况和前线轨道理论推测, 阴离子捕收剂很难与一水硬铝石(010)的表面Al原子间发生化学作用, 却容易与水硬铝石(010)的表面H原子相互作用.     

浮选柱研究和应用进展

简要回顾了浮选柱发展的历史，对其近几十年的研究和应用进展进行了较全面的论述，并对其今后的发展趋势进行了预测。     

巯基乙酸在铜钼分离中的应用

对用于铜钼浮选分离的各类抑制剂进行了分类；详细介绍了巯基乙酸在铜钼浮选分离中的应用进展，并对其抑制机理的研究也进行了系统的阐述；针对巯基乙酸的市场供需情况，展望了用于有机抑制剂的巯基乙酸的研究发展趋势。     

非极性表面矿物滑石与辉钼矿浮选分离中的多糖抑制

多糖作为非极性矿物表面抑制剂应用非常普遍,但关于其抑制机理和影响其抑制的因素研究还未完善。将国内外有关采用糊精、羧甲基纤维素（CMC）、木质素磺酸盐及古尔胶抑制滑石和辉钼矿的研究进行了总结,介绍了多糖抑制剂抑制非极性表面的研究进展,并从浮选分离滑石和辉钼矿的角度分析了这4种有机抑制剂对这2种矿物抑制的影响因素和抑制效果。研究表明,多糖的抑制效果不仅与矿浆的pH值、离子强度和离子种类有关,还与多糖分子的特性有关;在2种矿物的浮选分离方面,除了木质素磺酸盐能够高效率地分离滑石和辉钼矿外,十二烷在辉钼矿表面的吸附可有效阻止木质素磺酸盐的吸附,使木质素磺酸盐也可能成为滑石和辉钼矿有效分离的抑制剂;多糖对2种矿物的抑制不能仅从吸附量方面阐释,更重要的是多糖吸附层的特性;关于多糖的吸附机理则存在争议,主要有疏水力论、静电力论、化学力论、氢键和羟基作用论,或它们的综合作用论。     

Tween80在一水硬铝石浮选中的作用

采用浮选试验、红外光谱和粒度分析研究Tween80对油酸钠浮选一水硬铝石的影响。结果表明:当Tween80与油酸钠以适宜的比例(质量比为1:9)混合时,有利于一水硬铝石的浮选;随着Tween80的增多,混合表面活性剂不利于一水硬铝石的浮选。加入Tween80强化了细粒级一水硬铝石的捕收,但没有明显改善油酸钠在低温下的捕收能力;油酸钠主要以阴离子形式吸附于一水硬铝石表面,且加入Tween80可能与油酸钠在一水硬铝石表面产生共吸附。