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1.
研究了从废镍催化剂中生产硫酸镍,废镍催化剂通过碱洗酸溶,除去杂质钡和硅之后,通过调节溶液的pH值进行精制和浓缩,以除去铁锌等杂质,在液固比(mL/g)为5、硫酸质量浓度为40%,浸泡时间为100 min,浸泡温度是95℃时镍的浸出率最高,可达到97.5%.最终得到的晶体通过X射线衍射和热重分析表明,其结构为N iSO4.6H2O,化学分析表明镍含量为22.6%.  相似文献   

2.
0 INTRODUCTIONElectrolessnickel platingtechnologywasamethodofdepositingnickelionsonthesurfaceofmetalmaterialswithdifferentshapes .Thisprocesshadspecialadvantages ,andwasthereforewidelyap pliedinaerospace ,electronics ,petrochemistry ,foodindustriesandsoon[1]…  相似文献   

3.
The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was elimina...  相似文献   

4.
The kinetics of leaching arsenic from Ni-Mo ore roasting dust was investigated. The effects including leaching temperature, particle size of the smelter dust, stirring speed, the coefficient β(the molar ratio of sodium chlorate to arsenic in the smelter dust) and the initial H+ concentration on leaching arsenic were studied. The results indicate that the leaching of arsenic increases sharply with the decrease of particle size. The orders of reaction with respect to H+ concentration and particle size are determinted to be 1.136 and 1.806, respectively. The leaching of arsenic reaches 99% under experimental conditions, the apparent activation energy is determined to be 11.157 kJ/mol, which is consistent with the values of activation energy for diffusion model The kinetics equation of leaching arsenic from the roasting dust could be expressed by a semi-empirical equation as 1-2/3η (1 -η)^2/3 = k0(c[H+])^1.136ro^-1.806 exp[(-11157 /RT)t].  相似文献   

5.
To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw s...  相似文献   

6.
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.  相似文献   

7.
为了对硫酸制备过程中产生的焙烧炉渣和污泥等固体废物进行类别鉴定,用硫酸硝酸-浸出毒性试验方法对某4个公司样品中的砷元素做了浸出特性研究.结果表明:以硫精砂为原料或部分含硫精砂为原料制酸工艺所造成的砷污染远大于以硫铁矿为原料的制酸工艺;污泥浸出液中,炉渣残渣粒径小于0.075 mm时砷含量最高可达36 mg/L;粒径在0.075~0.2 mm时砷含量最高达30 mg/L;粒径越小,砷浸出量相对越多.污泥浸出液中砷含量均远高于砷的浸出毒性限值浓度(5 mg/L)和污水综合排放标准中砷的限值浓度(0.5 mg/L),表明厂家未能严格执行“第一类污染物必须车间处理达标后外排措施”的要求,建议监管部门加强第一类污染物监控力度,切实落实相关法律法规.  相似文献   

8.
Electroless plating is a growing segment of metalfinishing, especially in the electronics industry. Inelectroless plating, metals are deposited onto the sur-face of a part without the use of electricity as a sourceof electrons. Instead, the bath solution supplies the e-lectrons for the deposition reaction. These baths are ex-tremely complex using a variety of chelating and/orcomplexing agents that hold the metals in the solution.Common chelating agents include ethylenediaminetet-raacetic acid …  相似文献   

9.
火焰原子吸收光谱法测定氧化铝催化剂中镍含量   总被引:2,自引:0,他引:2  
本文介绍一种准确测定微波电子回旋共振(ECR)等离子体法制备的负载型氧化铝基镍催化剂负载量的方法。将催化剂样品和消化液封装在聚四氟乙烯高压密封罐蜜中加热溶解,采用空气-乙炔火焰原子吸收光谱法测定此溶液。仔细考察基体对镍测定的影响,回收率是98.2%-101。8%,相对标准偏差是3.42%。  相似文献   

10.
ACID RECOVERY FROM WASTE SULFURIC ACID BY DIFFUSION DIALYSIS   总被引:1,自引:0,他引:1  
Intheprocessofsulfuricacidproductionfrompyrite,thefumeproducedinpyriteroastingiswashedwithdiluteacid,andagreatdealofwastesulfuricacidwiththeconcentrationof8%~10%isproduced[1].Thiswastesulfuricacidcannotbeuseddirectlybecauseofitsrelativelyhighimpurity…  相似文献   

11.
本文报道了 (BF_3·0Et_2+n—C_8H_(17)OH)(简称Ni—Al—B)体系催化丁二烯聚合动力学研究结果,得到聚合速率方程式为 -d[Bd]/dt=k[Ni]~0[A1]~(-1)[B]~0[Bd],A1/B≤1 -d[Bd]/dt=k′[Ni]~0[A1]~(-1)[B][Bd],A1/B>1 聚合表观活化能为49.2kJ·mol~(-1)。  相似文献   

12.
Leaching kinetics of acid-soluble Cr(VI) in chromite ore processing residue (COPR) using hydrofluoric (HF) acid solution as a leaching agent was investigated for potential remediation of COPR with industrial waste water containing HF. The results show that HF can effectively destabilize the Cr(VI)-bearing minerals, resulting in the mobilization of Cr(VI) from COPR into the leachate. Particle size significantly influences the leaching of acid-soluble Cr(VI) from COPR, followed by leaching time, whereas the effects of HF concentration and leaching temperature are slight and the influence of stirring rate is negligible. The leaching process of acid-soluble Cr(VI) from COPR is controlled by the diffusion through the product layer. The apparent activation energy is 8.696 kJ/mol and the reaction orders with respect to HF concentration and particle size is 0.493 8 and −2.013 3, respectively.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
以磺化硅胶为催化剂,以丙烯酸和正丁醇为原料合成丙烯酸正丁酯,系统地研究了磺化硅胶催化剂的用量、原料配比和回流时间对反应工艺条件的影响,以及催化剂的重复使用情况.结果表明,最佳反应工艺条件为催化剂质量占丙稀酸质量的2.5%,n(酸)∶n(醇)=1∶1.2,阻聚剂用量0.1g(占原料总量的0.6%),反应时间40min,反应温度115~120℃,酯化率达90.3%,反应平均产率为78.5%.此催化剂制备简单,催化活性高,后处理简便,符合绿色环保催化剂的发展趋势.  相似文献   

16.
The resources of refractory gold ores are abundant, and their effective treatment can bring good economic benefits. This paper in-vestigated the kinetics of leaching gold from refractory gold ores by ultrasonic-assisted electro-chlorination. The effects of ultrasound time ratio, initial hydrochloric acid concentration and leaching temperature on the kinetic parameters were discussed. It is found that the leaching ratio goes up with all the factors increasing. The reaction kinetics is controlled by diffusion. When ultrasound improves the diffusion by re-ducing the diffusion resistance, the activation energy increases to 37.1 kJ/mol.  相似文献   

17.
Silica is the major component of the acid leaching residue of asbestos tailing. The waterglass solution can be prepared by the reaction of the residue with sodium hydroxide aqueous solution. Compared to the high temperature reaction method, this process is environmental friendly and low cost. In this paper, the reaction process of the residue and the sodium hydroxide aqueous solution is optimized. The optimum reaction process parameters are as follows: the usage of sodium hydroxide is 26.4 g/100 g acid leaching residue, the reaction temperature is 90℃, the reaction time is 1 h, and the ratio of the liquid/solid is 2.0. The significance sequence of the process parameters to the alkali leaching reaction effect is the usage of sodium hydroxide > the ratio of the liquid/solid > the reaction time > the reaction temperature. The significance sequence to the leaching ratio of SiO2 is the ratio of the liquid/solid > the usage of sodium hydroxide > the reaction time > the reaction temperature. The significance sequence to the modulus of the sodium silicate is the ratio of the liquid/solid > the usage of sodium hydroxide > the reaction time > the reaction temperature. Under the optimum conditions, the leaching ratio of the SiO2 is 77.5%, and the modulus of the sodium silicate is 3.15. The XRD analysis result indicates that the major components of the alkali leaching residue are serpentine, talc, quartz and some albite.  相似文献   

18.
含钒灰渣中钒的酸浸效率直接影响了整个提钒工艺中钒的总回收率,同时,酸浸条件对钒的酸浸效率有着显著的影响作用.为获取含钒灰渣酸浸提钒工艺酸浸阶段的工艺条件,及含钒灰渣的酸浸特性,在对灰渣中钒的赋存状态进行全面分析的基础上,针对硫酸浓度、酸浸温度、酸浸时间和液固比等酸浸影响因素,在实验室分别进行了酸浸条件试验研究;分析酸浸液、酸浸残渣的成分,计算得到V2O5酸浸效率.试验结果表明:酸浸温度和硫酸浓度对酸浸效率起主要影响作用.合理工艺条件为:硫酸浓度为5.0~6.0mol/L,酸浸温度为115~120℃,酸浸时间为6h左右,液固比为2.5∶1~3∶1.在此条件下,V2O5酸浸效率达到85%以上.  相似文献   

19.
The recovery of nickel from molybdenum leach residue by the process of segregation roasting-sulfuric acid leaching-solvent extraction was investigated. The residue was characterized by microscopic investigations, using X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD) techniques and the residue after segregation roasting was characterized by chemical phase analysis method. A series of experiments were conducted to examine the mass ratio of activated carbon (AC) to the residue, segregation roasting time and temperature, sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, addition amount of 30% H2O2, stirring speed (a constant) on the leaching efficiency of nickel. A maximum nickel leaching efficiency of 90.5% is achieved with the mass ratio of AC to the residue of 1:2.5, segregation roasting time of 2 h, segregation roasting temperature of 850 °C, sulfuric acid concentration of 4.5 mol/L, liquid-to-solid ratio of 6:1, leaching time of 5 h, leaching temperature of 80 °C, addition of 30% H2O2 of 0.6 mL for 1 g dry residue. Under these optimized conditions, the average leaching efficiency of nickel is 89.3%. The nickel extraction efficiency in the examined conditions is about 99.6%, and the nickel stripping efficiency in the examined conditions is about 99.2%.  相似文献   

20.
以3,4-二甲基硝基苯为原料,在雷尼镍催化剂作用下催化加氢制备3,4-二甲基苯胺,通过气相色谱分析3,4-二甲基苯胺的纯度。考察加氢压力、加氢溶剂、加氢温度、底物浓度、催化剂用量等因素对加氢反应的影响。结果表明,以乙醇为加氢溶剂,加氢压力0.8 MPa、温度60℃、3,4-二甲基硝基苯初始浓度1.25mol/L、催化剂质量为3,4-二甲基硝基苯质量的5%时,3,4-二甲基硝基苯转化率和3,4-二甲基苯胺收率和3,4-二甲基苯胺纯度均达100%。  相似文献   

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