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以铋电解阳极泥经火法处理产生的碲渣为研究对象,采用水浸-酸浸二段浸出工艺,研究不同浸出温度、浸出时间、液固比及HCl浓度等参数下的碲浸出率,分析工艺参数对碲浸出率的影响。结果表明:水浸工艺下碲浸出率随着液固比、浸出温度和浸出时间的增加逐渐增大,水浸最佳条件为液固比4∶1、水浸温度55℃、浸出时间1 h,碲浸出率为67.2%;水浸渣酸浸工艺下碲浸出率随着液固比、浸出温度、浸出时间及HCl浓度的增加不断增大,水浸渣酸浸的最佳条件为液固比5∶1、浸出温度60℃、浸出时间4 h、浓度6 mol·L-1,碲浸出率为99.83%。采用水浸-酸浸二段浸出工艺,可以有效提高碲浸出率。 相似文献
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采用酸性氧化预处理—氧化浸出工艺对镍钼矿进行了浸出回收,并确定了各阶段的主要工艺参数。原矿先进行酸性氧化预处理去除碳,NaClO3用量为原矿质量的11%,硝酸浓度为1.0mol/L,90℃下反应1.5h后,再进行氧化浸出,其中H2O2的量为原矿质量的9%,液固比为4∶1,60℃下浸出1.5h。钼的浸出率可达99%左右,镍的浸出率在94%以上。 相似文献
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针对氰化提金工艺酸浸渣中低品位金属铅的综合回收,采用盐浸法对金属铅进行了浸出实验研究,通过正交试验详细考察了浸出液固质量比、浸出温度、氯化钠浓度、浸出pH和浸出时间等因素对浸铅率的影响。结果表明,浸出液固质量比为5、浸出温度为333.15 K、氯化钠质量分数为30%、pH=0、浸出时间为4 h的实验条件下,最佳平均浸铅率为92.05%,相对标准偏差RSD=4.3‰;室温下最佳平均浸铅率为90.20%,RSD=4.1‰。因此,酸浸渣常温盐浸提铅是综合利用矿产资源回收铅及提高金、银回收率的有效途径。 相似文献
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在常压、较低温度(≤100℃)下,开展了煤气化粉灰硫酸浸出工艺条件的研究。以煤气化粉煤灰中Al2O3的浸出率为主要考察指标,通过单因素条件实验和正交实验,分别考察了粉煤灰活化焙烧温度、酸浸反应温度、酸浸反应时间、硫酸溶液质量浓度、液固比等因素的变化对煤气化粉煤灰中Al2O3浸出率的影响。在无需活化焙烧、不使用助剂的条件下,确定较适宜的酸浸工艺条件为:酸浸反应温度95℃、酸浸反应时间5h、硫酸溶液质量浓度40%、液固比4.5:1;此条件下的重复实验表明煤气化粉煤灰中Al2O3的平均浸出率为94.87%。 相似文献
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石煤灰渣二次焙烧稀酸浸出提钒工艺条件 总被引:2,自引:0,他引:2
为获得石煤灰渣二次焙烧稀酸浸出提钒工艺的优化条件,对该工艺钒浸出率的影响因素进行了实验研究.结果表明,二次焙烧温度、二次焙烧时间、熟料粒径、酸浸温度、硫酸浓度5种因素对钒浸出率的影响较大,酸浸液固体积质量比、酸浸时间的影响较小.最佳工艺条件为:二次焙烧温度850℃,二次焙烧时间1h,熟料粒径180μm以下,常温(18℃)酸浸,硫酸浓度0.36mol/L,液固比2~2.5mL/g,浸出时间0.25h.在此条件下,石煤灰渣钒浸出率可达81%以上. 相似文献
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针对硫酸法湿法磷酸工艺分解磷钾矿难以实现工业规模化连续生产的问题,提出了硝酸法加工磷钾矿的新技术。研究了反应温度、液固质量比、硝酸质量分数、颗粒细度等因素对硝酸浸出磷钾矿中磷浸出率的影响,结果表明:磷浸出率随着反应温度、液固质量比、硝酸质量分数的增加而增加,而随着磷钾矿粒度和磷酸浓度的增加而减小;在温度为50℃、液固质量比为7.3∶1、硝酸质量分数为40%、反应时间为1 h条件下,磷、钾浸出率分别为96.62%、2.45%,实现了磷的高效浸出和磷钾元素的分离。动力学分析表明,磷元素的浸出属于固体产物层扩散控制,活化能为4.77 kJ/mol,研究结果可为磷钾矿的利用提供新思路。 相似文献
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The results of a leaching study of used photographic films containing silver with nitric acid are presented. Effect of reaction time, reaction temperature and acid concentration on silver dissolution efficiency was determined. The results obtained show that leaching of about 98% of silver is achieved using − 2 mm spent (used) photographic film size at a reaction temperature of 90 °C for 50 min reaction time with 6% nitric acid concentration. Different solid:liquid ratios of 1:10 to 1:50 g/ml were also studied. Cementation study indicates that practically 100% of silver is deposited with addition of Zn metal powder. SEM photomicrographs show that sphere particles of about 1 μm diameter were obtained. 相似文献
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实验研究了银铟在复杂硫化锌精矿加压酸浸过程中的行为,考察了浸出温度、浸出时间、硫酸浓度、氧压、精矿粒度及液固比对铟浸出率和银入渣率的影响,分析了铟在浸出初期的动力学. 结果表明,在浸出温度150℃、浸出时间90 min、硫酸浓度152 g/L、氧分压1.2 MPa、精矿粒度<45 mm及液固比5 mL/g的条件下,铟浸出率达76%以上,银入渣率达98%以上. In的初期浸出符合核收缩模型,受界面化学反应控制,表观活化能为70.67 kJ/mol. 相似文献
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Traditionally, Ag-containing solid wastes are leached by nitric acid in order to recycle the noble metal. However, the huge amounts of emission of toxic nitrogen oxides demand the development of a new method for silver recycling. Recently, considering the Ce(IV) solution could be regenerated with electrolyzation method, our group invented a novel environmentally friendly process by using Ce(IV) as the oxidant to dissolve silver from the spent Ag/α-Al2O3 catalysts without NOx emission. To find out the optimal parameters, in this work, the leaching reaction was thoroughly investigated with respect to the temperature, oxidant and HNO3 concentrations, stirring speed, and time. The optimized leaching reaction gave the leaching silver rate 99.8% in 1 h. The kinetic plots suggested a shrinking core model with the internal diffusion-controlled process and the activation energy of 38.83 kJ·mol-1. The order in which the experimental conditions influence the reaction was determined through orthogonal analysis:temperature > oxidant concentration > HNO3 concentration > stirring speed. 相似文献
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为回收某低品位锰银矿中的锰、银金属,试验以硫铁矿作还原剂,用硫酸浸出矿石中的锰;浸锰渣用硫脲浸出银。针对试样矿石,试验研究了浸出的工艺条件,选择适宜的浸出工艺进行试验,锰的浸出率达到97.10%,银的浸出率达88.91%。 相似文献
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Sono-chemical leaching of uranium 总被引:1,自引:0,他引:1
Balasubrahmanyam Avvaru S.B. Roy Yogesh Ladola Sujit Chowdhury K.N. Hareendran Aniruddha B. Pandit 《Chemical Engineering and Processing: Process Intensification》2008,47(12):2107-2113
A fundamental study on the mechanism of uranium leaching in nitric acid and sulphuric acid media has been carried out to understand the effect of the ultrasound on leaching. The use of ultrasound clearly improves the leaching rate within the studied leach acid media. The enhancement in the leaching rate in the presence of ultrasound is higher with low leach acid concentration of nitric acid (HNO3), and it is high at high leach acid concentration in the case of sulphuric acid (H2SO4) being used as a leachant, when compared to conventional mechanical agitation. The basic reason behind this observed variation is explained on the basis of the reaction mechanism involving the oxidative conversion of acid insoluble tetravalent uranium form to the soluble hexavalent form of uranium in the presence of ultrasound at a faster rate. 相似文献
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采用HNO3对丝光沸石(HM)进行脱铝改性,并采用固定床反应器对其萘异丙基化反应的性能进行评价,考察了不同脱铝方式和不同Si/Al原子比对改性HM萘异丙基化性能的影响。结果表明,水蒸汽和硝酸处理的催化剂,其B酸与L酸的比例和酸强度分布可发生变化,在保持较好的萘转化率的前提下,提高了2,6-二异丙基萘(2,6-DIPN)的选择性。随着HNO3改性后HM分子筛的Si/Al原子比的增加,催化剂活性逐渐降低,稳定性提高,选择性先提高后降低。适宜的硝酸改性脱铝工艺条件为:HM沸石先经500℃、0.5h-1的空速下高温水蒸汽处理1.0h,再用1.6mol/L的HNO3溶液于45℃下处理24.0h,此时Si/Al原子比为31,2,6-DIPN的产率为7.24%。 相似文献
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A hydrometallurgical process to extract silver from the silver-lead ore in Boorchi, Mongolia by using thiourea leaching solution is studied in this work. Through the observation of optical and scanning electron microscopes, and energy spectral analysis, it is determined that 5 kinds of silver minerals exist in the ore, including argentite, Ag-tetrahedrite, Ag-Zn-Sb-tetrahedrite, freibergite and acanthite. The experimental results of direct thiourea leaching of the ore show that 56%~60% of silver is leached. The main reason for the low leaching rate is due to silver minerals enveloped in galena and other minerals, even though the ore is ground to the particle size of 75 mm. When the ore is pretreated with ammonium carbonate solution under oxidation, the experimental results of thiourea leaching show that the leaching rate of silver increases to near 75% with the pretreatment. Based on the leaching experiments, a principle hydrometallurgical technological route to extract silver from the Ag-Pb ore is proposed. 相似文献