湿法炼锌除钴锌渣硫酸浸出液中高锰酸钾氧化沉钴热力学分析

锌湿法冶金生产中除钴产出的锌渣尚含有大量的锌钴等有色金属资源,这种渣用硫酸浸出后锌钴等有色金属进入浸出液中,可用高锰酸钾等氧化剂将钴氧化沉淀而从含锌溶液中分离出来.用电极电势理论和能斯特方程对此除钴过程进行了热力学分析,结果表明:高锰酸根的氧化对溶液中杂质Fe2 、Mn2 、Co2 的去除是可行的,可以达到工业生产对杂质的浓度要求;对于N i2 只能进行部分氧化.氧化过程中溶液pH对钴的沉淀效果具有决定性影响,pH低于4时沉淀效果将显著降低.     

超声电氧化辉钼精矿研究

考察了辉钼精矿在电解NaCl溶液环境下的氧化行为及超声波对氧化浸出过程的影响.结果表明:无超声场强化时浸出表现活化能Ea较小,仅为19.7 kJ/mol,浸出过程是固膜扩散控制,漫出过程中生成的硫会形成强疏水性的致密硫膜,尤其是在堆积密度高的矿物基面上,会阻止氧化反应的进一步进行,对未反应完全的MoS2起保护作用.在无超声波的漫出过程中,浸出4 h Mo的浸出率为88%,采用超声场强化浸出过程,可以加快和强化辉钼矿的氧化分解,超声波每隔10 min发射5 min,液固比20,搅拌速度500 r/min,浸出温度40℃,NaCl浓度4 mol/L,PH为9(初始),浸出时间4 h的条件下,Mo浸出率可以达到99.6%.     

低品位氧化锌矿在NH_3-NH_4HCO_3-H_2O体系中的浸出动力学研究（英文）

对高钙低品位氧化锌矿在NH3-NH4HCO3-H2O体系中的浸出动力学进行了系统研究.研究结果表明,氧化锌矿浸出过程遵循＂未反应核缩减＂模型,即遵循动力学方程：1-（1-α）1/3=k.t.反应的表观活化能Ea=6.489 kJ/mol,浸出过程由外扩散过程控制.增强搅拌强度、提高总氨浓度及反应温度均可加快该矿石中锌的浸出速率,并在一定范围内提高锌的浸出速率.     

NULL—WILSON热力学模型在离子交换平衡系统中的应用研究

本文为应用Null—wilson模型来描述Na~+—H~+体系的离子交换平衡,其结果令人满意。全文详述了理论处理和实验方法的具体过程;采用了NaCl溶液与H——型国产732~#磺酸型树脂的平衡体系,在温度为25℃,溶液总浓度为0.2N、0.4N的条件下的测得的。实验数据通过理论计算所得的热力学平     

用Fe_2(SO_4)_3-H_2SO_4浸出含有磁黄铁矿,镍黄铁矿,黄铁矿和黄铜矿矿物的复合镍黄铁矿矿石的数学模型

研究提出了用Fe_2(SO_4)_3-H_2SO_4溶液溶解复合镍黄铁矿矿石时确定溶液中浓度变化的数学模型。此复合镍黄铁矿含有四科矿物:磁黄铁,镍黄铁矿,黄铁矿和黄铜矿矿物。镍赋存于磁黄铁矿和镍黄铁矿两种矿物中,钴赋存于镍黄铁矿和黄铁矿两种矿物中,而铜赋存于黄铜矿物中。当建立这样一个浸出过程模型时,必须考虑两种不同类型的反应,即多相溶解反应和均相溶液反应。溶解反应是动力学控制反应速度的反应,反应速度很慢,以致可将溶液反应视为处于连续平衡反应。在这种情况下考虑采用部分平衡法建立     

电解法用于促进蛇纹石矿物固定CO2的研究

采用自制的电解反应器来电解NaCl溶液,利用阳极产生的酸性溶液溶解出蛇纹石中的镁离子,用阴极产生的碱性溶液吸收模拟烟气中CO2,然后将反应后的两极溶液混合形成MgCO3沉淀.结果表明：在电流强度在0.5 A时电解效率最高,电流效率与NaCl溶液的浓度关系不大.在阳极得到的酸性溶液用于溶解蛇纹石中的镁,其性能与相同pH值的盐酸溶液相差不大,可以用于直接浸取蛇纹石中的镁.用阴极得到的碱性溶液吸收模拟烟气中的CO2,得到的溶液与浸取出的Mg2＋在85℃下反应可以得到固体沉淀.干燥后采用XRD以及TGA对固体沉淀进行表征,发现产物为较纯净的碱式碳酸镁[Mg5（CO3）4（OH）2.4H2O],这种物质在环境中是稳定、无害的而且还具有一定的经济意义.该方法可用于氯碱工业比较发达的地区,其阳极产生的酸性废液可以充分利用,而阴极产生的碱性溶液也不必进行分离即可进一步反应,该过程在相对低温以及常压下进行,同时还得到H2与Cl2,以及较纯净的固体产品,因此可以大大降低矿化成本.     

金属配合物溶液的热力学研究 Ⅰ.Pb(Ⅱ)—Cl~-配位体系

本文在Pb(Ⅱ)—Cl~-配位体系的热力学研究中,应用Pitzer方程计算高浓、复杂的配合物溶液的活度系数.在无支持电解质存在下,设计安排了无液接电势的电动势法,测算了Pb(Ⅱ)—Cl~-体系在35℃配位反应的热力学平衡常数以及配离子的活度系数式中的维里系数值.计算了25℃时热力学平衡常数和不同离子强度下的浓度平衡常数.成功地预测了25℃时PbCl_2在NaCl溶液中的溶解度.     

硫脲法从锌的酸浸渣中回收银

研究了从湿法炼锌酸浸渣中用硫脲浸出银的工艺及机理，对浸出过程中的各种影响因素如矿浆浓度、浸出剂浓度、反应温度、反应时间、ＰＨ值等分别进行了试验研究和分析讨论，给出了最佳工艺条件，在此条件下，银浸出率达８９％。     

一种改性钛渣钛组分的分离方法

研究了碱浸出过程中的影响因素,考察了浸出温度,NaOH溶液的浓度,以及物料粒度和液固比等因素对于浸出效果和回收率的影响.得到了碱浸阶段适宜的工艺条件为：溶液中NaOH的质量分数为15%、浸出温度100℃、浸出时间6 h、液固比20 mL/g、钛渣粒度小于38μm,搅拌速度500 r/min.采用三段浸出的方法获得了品位为91.42%,回收率为78.47%的人造金红石产品.     

电镀污泥中铬的无害化处理及动力学分析

以某表面处理工业园电镀废水处理污泥为研究对象,以铬浸出率为指标,通过对重金属的浸出,分步回收达到无害化、资源化的目的.将污泥干燥、研磨,在不同浓度硫酸溶液中浸出,控制浸出时间、浸出温度和搅拌速率;浸出完成后抽滤使浸出液与残渣分离.采用正交试验法,确定对铬浸出效果影响因素的顺序为:硫酸浓度>搅拌速度>浸出时间>固液比.通过单因素优化试验,结果显示:当浸出温度为25 ℃、固液比为1∶15、浸出时间为20 min、搅拌速率为800 r/min、硫酸体积分数为30%时,铬的浸出率最高.最后用黄钠铁矾法除铁,用焦亚硫酸钠还原六价铬,用氢氧化钠分步沉淀铬、镍重金属,锌则继续留在溶液中.电镀污泥的浸铬实验的浸出动力学研究结果表明硫酸作为浸出剂的反应级数为1,反应的速率常数为:k=0.053 2e-4.52/RT.     

Kinetics of the leaching of TiO2 from Ti-bearing blast furnace slag

Ti-bearing blast furnace slag is a valuable secondary resource containing about 24 percent of TiO2. In this paper a process of leaching Ti-bearing blast furnace slag with sulfuric acid to recover TiO2, and the kinetics of that reaction, are described. Under laboratory conditions the rate is controlled by a chemical reaction. The leaching reaction is in accord with a shrinking un-reacted-core model. The apparent reaction order of the leaching reaction was 1.222 and the apparent activation energy was 87.01 kJ/mol. The model fits the observed data well until 90% of the TiO2 has be leached from the particles. The model disagrees with observations during later periods of the reaction because the solution becomes supersaturated with Ti ions, which precipitate as H2TiO4. The assumptions of constant reactant concentration and that there is no effect from the product layer on diffusion, also cause the model to deviate from the actual values.     

Experimental Study of Fluorine Transport Rules in Unsaturated Stratified Soil

With the aid of soil column test models, the transport rules of fluorine contaminants in unsaturated stratified soils are discussed. Curves of F- concentrations at different times and sites in the unsaturated stratified soil were obtained under conditions of continuous injection of fluoride contaminants and water. Based on the analysis of the actual observation data, the values between computed results and observed data were compared. It is shown that the chemical properties of fluorine ions are active. The migration process of fluorine ions in soils is complex. Because of the effect of adsorption and desorption, the curve of the fluorine ion breakthrough curve is not symmetric. Its concentration peak value at each measuring point gradually decays. The tail of the breakthrough curve is long and the process of leaching and purifying using water requires considerable time. Along with the release of OHˉ in the process of fluorine absorption, the pH value of the soil solution changed from neutral to alkalinity during the test process. The first part of the breakthrough curve fitted better than the second part. The main reason is that fluorine does not always exist in the form of fluorinions in groundwater. Given the long test time, fluorinions possibly react with other ions in the soil solution to form complex water-soluble fluorine compounds. Only the retardation factor and source-sink term have been considered in our numerical model, which may leads to errors of computed values. But as a whole the migration rules of fluorine ions are basically correct, which indicates that the established numerical model can be used to simulate the transport rules of fluorine contaminants in unsaturated stratified soils.     

Cyanex 301修饰Ag_2S纳米粒子的制备及表征

在醇/水混合介质中,用共沉淀法制备了Cyanex 301(二(2,4,4-三甲基戊基)二硫代膦酸)修饰的Ag2S纳米粒子。用XRDI、R、TEM、UV-Vis和TG等表征了粒子的形貌与结构。结果表明,将表面吸附了Cyanex 301的纳米粒子分散到有机溶剂中能形成稳定的含硫化银纳米粒子的有机流体,其负载量随溶剂极性的增大而降低。     

水溶液中重铬酸钾与硝酸银反应产物的研究

本文研究了水溶液中重铬酸钾与硝酸银反应生成的沉淀产物的组成,以及反应物浓度和溶液体积对沉淀产物组成的影响。实验证明,K_2Cr_2O_7与AgNO_3反应生成的沉淀通常是Ag_2CrO_4和Ag_2Cr_2O_7的混合物。但在特定操作条件下可获得单一的Ag_2CrO_4沉淀。     

Recycling of Spent Nickel-Cadmium Batteries

A technique for recycling spent nickel-cadmium batteries, which makes separaion of cadmium and nickel possible, is developed by laboratory-scale experiments. NH3-H2CO3 aqueous solution was used in this leaching technique. Since neutralization and/or solvent extraction were not required in the separation procedure of nickel and cadmium, the closed systemizaion of the process becomespossible. Experimental results show that, (1) if the NH3 concentraion of leaching solution is sufficiently high and the ratio of H2CO3 toNH3 is properly adjusted, both Ni(OH)2 and Cd(OH)2 react with NH, and quickly dissolve into leaching solution, and (2) Ni(OH)2 can beconverted into insoluble NiO by calcination at 500℃, and CdO from Cd(OH)2 by calcination maintains good solubility in NH3-H2CO3aqueous solution. As a conclusion, the recycling technique characterized by two step leaching can be developed based on such changesin dissolution behavior by calcination. Meanwhile, the yields of 99.8% for nickel and 97.6% for cadmium are obtained, and the puritiesof Recycling of Spent Nickel-Cadmium BatterieRecycling of Spent Nickel-Cadmium Batteries Recycling of Spent Nickel-Cadmium Batteriesrecovered nickel and cadmium are 99.9% and 98.6%, respectively.     

城市垃圾渗滤液烟气脱硫体系气液吸收与解吸过程的数学模拟

针对垃圾渗滤液烟气脱硫体系气液吸收和解吸过程反应复杂的特性,基于经典双膜传质理论,建立了填料塔内湿法烟气脱硫模型,包括填料塔反应器模型和烟气SO2在垃圾渗滤液中吸收并伴随氨的解吸过程的数学模型。模型将系统内复杂的多组分反应分解为独立的离子反应,从而在确定的独立反应的条件下,可使模型的数值求解不依赖于特殊的假设条件以及可变的操作条件。根据工艺研究的实验条件对模型赋初值,结合模型参数估值确定适宜的边界条件,采用Maple 8.0对模型方程进行求解,得到了液膜内各组份的浓度分布特性曲线,以及气相分压、pH值、传质阻力、传质速率、吸收增强因子等沿塔高的分布特性,结果表明模型预测结果和实验结果吻合良好。所建立的模型为本工艺过程和其它湿法烟气脱硫过程的传质-反应现象提供了一个定量的理论分析和工程设计基础。     

Electrogenerative leaching of nickel sulfide concentrate with ferric chloride

In order to utilize the chemical energy in hydrometallurgical process of sulfide minerals reasonably and to simplify the purifying process, the electrogenerative process was applied and a dual cell system was introduced to investigate FeCl3 leaching of nickel sulfide concentrate. Some factors influencing the electrogenerative leaching, such as electrode structure, temperature and solution concentration were studied. The results show that a certain quantity of electrical energy accompanied with the leached products can be acquired in the electrogenerative leaching process.The output current and power increase with the addition of acetylene black to the electrode. Varying the components of electrode just affects the polarization degree of anode. Increasing FeCl3 concentration results in a sharp increase in the output of the leaching cell when c(FeCl3) is less than 0.1mol/L. The optimum value of NaCl concentration for electrogenerative leaching nickel sulfide concentrate with FeCl3 is 3.0 mol/L. Temperature influences electrogeneratire leaching by affecting anodic and cathodic polarization simultaneously. The apparent activation energy is determined to be 34.63 kJ/mol in the range of 298 K to 322 K. The leaching rate of Ni^2 is 29.3% after FeCl3 electrogenerative leaching of nickel sulfide concentrate for 620 min with a filter bag electrode.     

蔗渣木质素对溶液中重金属离子的吸附性能

研究了蔗渣木质素在不同的吸附时间、pH值、溶液浓度、木质素用量等条件下对Pb2+、Cd2+、Hg2+3种重金属离子的吸附作用,探讨了蔗渣木质素的等温吸附规律及吸附性能。实验结果表明:木质素吸附平衡时间约为15 min;溶液pH值是影响木质素对重金属吸附能力的主要因素,吸附量随pH值升高而增加;木质素对3种重金属离子皆有一定的吸附作用,吸附量次序为Pb2+(21.62 mg/g)Hg2+(7.65mg/g)Cd2+(3.32 mg/g)。Redlich-Peterson与Langmiur等温吸附模型可以较好的描述蔗渣木质素对3种重金属离子的吸附特性,其吸附过程属于优惠吸附。本结果可为用蔗渣木质素开发吸附重金属食品添加剂提供科学依据。     

浸铜渣中提银的研究

用严充酸和硫化硫酸盐的溶液浸出浸铜渣回收银,研究了影响浸出过程的主要因素,讨论了堆浸的作用问题。对于含银２００ｇ／ｔ的浸铜渣,银的回收率达８０％以上。     

钢包炉废渣水热浸出去硫反应机理研究

采用水热法对钢包炉废渣中硫进行浸出去除,并分析其浸出机理和热力学影响因素。钢包炉废渣中的硫在水热浸出处理过程中是以S^2-形式进入浸出液中,与水离解出的H＋结合先形成HS^-,而后进一步形成H2S,最终达到将废渣中硫浸出去除的目的。废渣中硫的水热浸出过程为吸热反应,△rH0=29570J／mol,标态下温度丁〉450K时,反应能自发进行,提高温度有利于硫的浸出。影响浸出过程的热力学因素有温度和硫化氢分压。T〈850K时,硫的浸出主要受温度的影响;T〉850K时,硫的浸出主要受硫化氢分压的影响。本实验温度条件下,温度为浸出过程的主要热力学影响因素。