电解浸出软锰矿的研究

采用电解法浸出软锰矿,考察硫酸铁用量、硫酸用量、浸出时间、电流密度、液固比、反应温度和搅拌速率对锰浸出率的影响。结果表明,在铁锰物质的量之比为1:2,硫酸物质的量浓度为0.1 mol/L,浸出时间为2 h,电流密度为400 A/m2,液固比为7:1,反应温度为80℃,搅拌速率为300 r/min的优化工艺条件下,锰的浸出率达95%以上。     

硫酸锰热解制备Mn2O3以及用热解尾气浸出低品位软锰矿的实验研究

用硫酸锰(MnSO4)高温热解的方法制备了三氧化二锰,并考察了热解制备过程中产生的尾气浸出低品位软锰矿的可行性。热解实验表明,850℃是硫酸锰热解制备三氧化二锰的最佳温度。硫酸锰在850℃热解所得三氧化二锰产品的锰含量为68.93%。产品的XRD和FTIR表征结果表明,热解产物为单一相的立方体结构三氧化二锰。尾气测定结果表明硫酸锰热解制备三氧化二锰时释放出的尾气中含有SO2和SO3, 两者摩尔比约为7:1。浸出实验结果表明利用热解尾气浸出软锰矿是完全可行的。在温度为60℃,初始硫酸浓度为0.1mol/L时,尾气中SOx（SO2和SO3）的吸收率达到99.73 %,软锰矿的锰浸出率达到94.37 %。该工艺不仅可以避免液相制备方法中废水的问题,还可以使得热解制备过程产生的尾气和低品位软锰矿同时得到资源化利用。     

201×7强碱性阴离子交换树脂吸附浓海水中溴的动力学研究

研究了201×7强碱性阴离子交换树脂吸附浓海水中溴的动力学行为,测定了吸附率随时间的变化关系,考察了温度、溶液初始浓度、搅拌转速和pH值对树脂吸附溴的动力学实验的影响.研究表明:该树脂对溴的最大吸附量为2.489 4 mg/mL;吸附过程的控速步骤主要为颗粒扩散控制;吸附过程的表观活化能Ea=8.98 kJ/mol,反应级数n=0.531 4;搅拌转速对该吸附过程的影响不大;pH值控制在3.0~3.5范围内有利于树脂对溴的吸附.     

两矿法浸出软锰矿的工艺与理论

对国内流行的黄铁矿－软锰矿两法硫酸浸出软锰矿工艺进行了研究。结果表明，在一般的工艺条件下，锰浸出率较低，延长浸出时间对锰浸出率影响不大，而提高硫酸用量则使锰浸出率明显降低，此外，对该工艺过程的机理进行了分析，认为浸出过程中黄铁矿的氧化产物Ｓ＾０和ＳＯ４＾２－竞争反应的并行存在，消耗了大量的黄铁矿，同时，强疏水性的元素硫Ｓ＾０的生成也阻碍了浸出反应的进一步进行，使实际浸出反应所需的黄铁矿量增加。     

pH值缓冲剂及烟气氧含量对软锰矿浆烟气脱硫体系的影响

软锰矿浆烟气脱硫工艺能利用软锰矿中的MnO2与烟气中的SO2反应生成副产品硫酸锰,喷射鼓泡反应器(JBR)适宜于该工艺体系,但在单级JBR反应器中进行软锰矿浆烟气脱硫很难同时实现较高的脱硫率(η(SO2))和锰浸出率(X(Mn))。针对这一问题,通过实验在JBR反应器中考察了pH值缓冲剂添加比例和烟气氧含量对软锰矿浆烟气脱硫体系的影响,确定烟气氧含量为21%时pH值缓冲剂的最佳添加比例为30%,烟气氧含量为7%时pH缓冲剂的最佳添加比例为10%。结果表明,在模拟燃煤烟气的条件下,体系中pH值缓冲剂的添加比     

硫酸锰热解制备Mn_2O_3以及用热解尾气浸出低品位软锰矿的实验研究

用硫酸锰(MnSO4)高温热解的方法制备了Mn2O3,并考察了热解制备过程中产生的尾气浸出低品位软锰矿的可行性。热解实验表明,850℃是硫酸锰热解制备Mn2O3的最佳温度。硫酸锰在850℃热解所得Mn2O3产品的锰含量为68.93%。产品的XRD和FTIR表征结果表明,热解产物为单一相的立方体结构Mn2O3。尾气测定结果表明,硫酸锰热解制备Mn2O3时释放出的尾气中含有SO2和SO3,两者摩尔比约为7∶1。浸出实验结果表明利用热解尾气浸出软锰矿是可行的。在温度为60℃,初始硫酸浓度为0.1 mol/L时,尾气中SO x(SO2和SO3)的吸收率达到99.73%,软锰矿的锰浸出率达到94.37%。该工艺不仅可以避免液相制备方法中废水的问题,还可以使得热解制备过程产生的尾气和低品位软锰矿同时得到资源化利用。     

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.     

盐酸浸出焙烧金精矿动力学研究

在盐酸体系中,Fe~(3+)可以氧化金生成AuCl_4~-,利用这一反应,开展了搅拌速率、反应温度、盐酸浓度、液固比和反应时间对盐酸与焙烧金精矿反应浸出金的小型试验研究,同时对浸出条件进行了优化,确定了该反应的动力学模型.获得优化工艺条件为:温度90℃,盐酸浓度8 mol/L,液固比1.5∶1,反应时间90 min,搅拌速度400 r/min,反应温度、盐酸浓度对浸出反应影响显著,优化条件下浸出率高达95.53%;利用动力学方法对实验数据进行拟合,发现该反应属于收缩核模型反应,较好地符合1-(1-x)~(1/3)=k_1t方程,经过数据处理,得到反应表观活化能E_a=13.88 kJ/mol,浓度反应级数为0.61,速率常数0.16.     

固定床中PET固相聚合的研究

本文利用固定床反应器对N2保护下的PET固相聚合反应进行研究，在低于粘结点温度下预聚合之后再实施高温聚合，可消除切片粘结，提高反应速率及产品质量，建立了化学反应和扩散过程共同控制下的动力学模型，其计算结果表明从粒子中心到表面，固相聚合表现反应速率和分子量随副产物小分子（乙二醇和水）的浓度减小而增大，并且描述了反应温度、载气中小分子含量和预聚体切片粒径对反应的影响，为优化工艺操作，提高产品质量提供了理论依据。     

悬浮聚合法制备负离子聚合物微球的研究

以聚氨酯(PU)增稠的甲基丙烯酸甲酯(MMA)为分散剂、硅烷偶联剂KH-570为表面改性剂,通过球磨法利用偶联剂对超细负离子粉表面进行有机官能团改性,并制得悬浮性良好的分散料浆,再以此为分散相、水为连续相、聚乙烯醇(PVA)为分散稳定剂、过氧化苯甲酰(BPO)为引发剂,通过悬浮聚合制备包含有超细负离子粉末的聚合物微球。对微球制备过程中相关因素的分析结果表明:随着分散阶段搅拌速度的增大,微球粒径减小、负离子粉包覆率降低;聚氨酯含量的适当增加可以相应提高微球中负离子粉的有效含量;当搅拌转速为550r/min、BPO含量为1.4%、PVA浓度4.3%、PU加入量5.0%时,可以制得平均粒径25μm、负离子粉包覆率较好的聚合物微球。     

搅拌强度对软锰矿浆湿法脱硫反应的影响

考察在不同搅拌强度下SO2的脱硫率及锰离子浸出率，在低转速范围，溶液中脱硫反应主要以MnO2和SO2为主，基产物主要为硫酸锰。在高转速范围，由于溶液中溶解氧浓度增大，脱硫反应则为在Mn^2 、Fe^2 催化下，水吸收SO2脱硫和MnO2与SO2氧化脱硫反应并存，其产物为硫酸锰和稀硫酸的混合物。     

Dissolution kinetics of malachite in ammonia/ammonium sulphate solution

The dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution. The effects of ammonia and ammonium sulphate concentration, pH, leaching time, reaction temperature, and particle size were determined. The results show that the optimum leaching conditions for malachite ore with a copper extraction more than 96.8% are ammonia/ammonium concentration 3.0 mol/L NH₄OH + 1.5 mol/L (NH₄)₂SO₄, liquid-to-solid ratio 25:1 mL/g, leaching time 120 min, stirring speed 500 r/min, reaction temperature 25 °C and particle size finer than 0.045 mm. The dissolution process of malachite with an activation energy of 26.75 kJ/mol is controlled by the interface transfer and diffusion across the product layer. A semi-empirical rate equation is obtained to describe the leaching process and the reaction orders with respect to concentration of ammonia and ammonium sulphate are 2.983 0 and 0.941 1, respectively.     

软锰矿烟气脱硫研究

在喷射鼓泡反应器（JBR）中采用软锰矿吸收烟气中SO2,并对影响脱硫率的因素液固比、矿浆初始pH、烟气流量、进口烟气浓度、矿粉粒度等进行了探讨。结果表明,采用的JBR反应器作为吸收设备,软锰矿脱除烟气中SO2效果明显（脱硫率＞90％）,经吸收液经过化学加工、精制后,可得工业上具有价值的化工原料MnSO4。     

Study on hydrometallurgical process and kinetics of manganese extraction from low-grade manganese carbonate ores

In order to utilize low-grade manganese ore resources effectively, a hydrometallurgical process was developed for manganese extraction in dilute sulfuric acid medium, and the kinetics of leaching manganese was also investigated. At room temperature, manganese from low-grade manganese carbonate ores was extracted by sulfuric acid leaching without reductants. During the extracting process, single-factor analysis method was used to evaluate the effects of grinding fineness, sulfuric acid concentration, liquid-to-solid ratio, agitation rate and leaching time on the leaching efficiencies of Mn and Fe. The optimal leaching conditions are determined as coarse particles of below 2 mm size (without ball-milling), sulfuric acid concentration of 0.86 mol/L, liquid-to-solid ratio of 5:1, agitation rate of 150 r/min and leaching for 180 min at room temperature. Under the optimal conditions, the leaching efficiencies of Mn and Fe are 96.21% and 13.35%, respectively. In addition, through the experiments at different temperatures, it is found that the leaching process follows the shrinking core model under the conditions of changing acid concentration and intermittent reaction device. Moreover, the apparent activations of effective diffusion and chemical reaction in the kinetic model are calculated to be 18.83 and 27.15 kJ/mol, respectively.     

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     

Molybdenum removal from copper ore concentrate by sodium hypochlorite leaching

The removal of molybdenum from a copper ore concentrate by sodium hypochlorite leaching was investigated. The results show that leaching time, liquid to solid ratio, leaching ternperature, agitation speed, and sodium hypochlorite and sodium hydroxide concentrations all have a significant effect on the removal of molybdenum. The optimum process operating parameters were found to be: time, 4 h: sodium hydroxide concentration, 10%; sodium hypochlorite concentration, 8%; liquid to solid ratio, 10:1; temperature, 50℃; and,agitation speed, 500 r/min. Under these conditions the extraction of molybdenum is greater than 99.9% and the extraction of copper is less than 0.01%. A shrinking particle model could be used to describe the leaching process. The apparent activation energy of the dissolution reaction was found to be approximately 8.8 kJ/mol.     

常压酸浸高冰镍的动力学研究

本文是关于常压酸浸高冰镍的动力学研究.实验考察了粒度、温度、硫酸浓度和氯离子浓度对镍浸出速率的影响.结果表明,在硫酸体系中选择性地浸出镍不仅在热力学上是可能的,而且反应速率快,完全能达到一次分离镍铜的目的.本文采用特殊的处理方法,将总镍浸出率R转换为Ni_3S_2中镍浸出率R~(?),从而导出实验条件下的动力学方程式.而浸出过程受通过产物层的固膜扩散控制.     

Leaching kinetics of low-grade copper ore with high-alkality gangues in ammonia-ammonium sulphate solution

The leaching kinetics of low-grade copper ore with high-alkality gangues was studied in ammonia-ammonium sulphate solution. The main parameters, such as ammonia and ammonium sulphate concentrations, particle size, solid-to-liquid ratio and reaction temperature, were chosen in the experiments. The results show that the increase of temperature, concentrations of ammonia and ammonium sulphate is propitious to the leaching rate of copper ore. The leaching rate increases with the decrease of particle size and solid-to-liquid ratio. The leaching rate is controlled by the diffusion through the ash layer and the activation energy is determined to be 25.54 kJ/mol. A semi-empirical equation was proposed to describe the leaching kinetics.     

Leaching kinetics of low grade zinc oxide ore in NH3-NH4Cl-H2O system

The leaching kinetics of low grade zinc oxide ore in NH3-NH4Cl-H2O system was studied. The effects of ore particle size,reaction temperature and the sum concentration of ammonium ion and ammonia on the leaching efficiency of zinc were examined.The leaching kinetics of low-grade zinc oxide ore in NH3-NH4Cl-H2O system follows the kinetic law of shrinking-core model. The results show that diffusion through the inert particle pores is the leaching kinetics rate controlling step. The calculated apparent activation energy of the process is about 7.057kJ/mol. The leaching efficiency of zinc is 92.1% under the conditions of ore particle size of 69μm, holding at 80℃ for 60min, sum ammonia concentration of 7.5mol/L, the molar ratio of ammonium to ammonia being 2:1, and the ratio (g/mL) of solid to liquid being 1:10.