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1.
金矿含氰废水处理技术 总被引:2,自引:0,他引:2
邹晓男 《广东微量元素科学》2008,15(11):12-15
介绍了金矿含氰废水的处理方法及新的处理技术,并对其原理及优缺点进行了分析。 相似文献
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The gold dissolution rate in alkali–cyanide solutions with and without bismuth hydroxy compounds is studied as a function of potential E, with the electrode surface renewed before taking measurements. At E < 0 (NHE), these ions accelerate the process. At more positive E, their influence is ambiguous. At negative potentials, the effect depends on the time of electrode contact with solution prior to beginning the measurements, the scan rate of E, and the KCN and KOH concentrations. Possible approaches are suggested to explaining the established regularities. 相似文献
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Effective values of order of the reaction of the gold dissolution process by cyanide ions p, transfer coefficient , and exchange current i
0 are measured at constant values of the coverage of the gold surface by bismuth adatoms . The constancy of is ensured by maintaining a constant value of the time t during which the electrode is in contact with solution after the renewal of its surface until the instant of taking measurements. The solutions under study contain 2.5 × 10–6 to 7 × 10–6 M bismuth hydroxy compounds, 0.1 M KCN, 0.01 M KAu(CN)2, and 0.1 M KOH. With increasing t, quantities p, , and i
0 increase from 0.17, 0.1, and 10–5 A cm–2, respectively, which are the values typical for the gold dissolution process in plain potassium cyanide solutions, to p 1.1, 0.45, and i
0 2 × 10–4 A cm–2. The increase in the quantity p by approximately a unity is interpreted as an evidence in favor of the assumption that the presence of bismuth adatoms alters the nature of the limiting stage: the latter starts involving cyanide ions localized outside an adsorption layer, rather than the adsorbed cyanide ions only, as is the case in plain solutions. A comparison of obtained results with the data of similar investigations performed earlier in thallium- and lead-containing solutions shows that possible mechanism of acceleration of anodic process suggested in the previous works may be used for explaining regularities of the gold dissolution process observed in the presence of bismuth adatoms as well. 相似文献
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Effective reaction order by cyanide ions, p, effective transfer coefficient ef, and exchange current i
0of the gold dissolution process are measured at a constant surface coverage by thallium adatoms Tl. The constancy of Tlis ensured by constant time tof the electrode's contact with solution after renewal of its surface and before starting the measurements. Solutions containing 2.5 × 10–6to 10–5M TlNO3, 0.1 M KCN, and 0.1 M KOH are studied. With an increase in t, quantities p, ef, and i
0increase from values typical for pure KCN solutions (0.17, 0.1, and 10–5A/dm2, respectively) to p 1.1, ef 0.4, and i
0 3 × 10–4A/dm2. The increase in pby nearly unity is interpreted as indicating a change in the limiting stage in the presence of thallium ions: in the latter case, it involves not only adsorbed cyanide ions (as in pure cyanide solutions), but also those located beyond the adsorption layer. A possible mechanism explaining the acceleration of gold dissolution in the presence of thallium adatoms is put forward. 相似文献
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十四烷基二甲基苄基氯化铵萃取Au(CN)2-的微观机理 总被引:4,自引:0,他引:4
通过萃取平衡、傅里叶变换红外光谱及分峰技术研究了季铵盐十四烷基二甲基苄基氯化铵(TDM-BAC)-磷酸三丁酯(TBP)-正庚烷体系萃取Au(CN)2-的机理及过程.提出了萃合物的结构模型是基于氢键的超分子体系,组成为[R4N+]·[Au(CN)2-]·4H2O·4TBP.当有机相金浓度大于3g·L-1时,有机相中存在聚集现象.通过激光光散射技术测定了有机相中反向胶团的大小,表明萃取过程是分散在水相中的胶团在协萃剂(或助表面活性剂)作用下溶入有机相,转型为反向胶团或微乳液(W/O型)聚集状态. 相似文献
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The effect of the electrode potential on the gold dissolution rate in alkali–cyanide solutions with and without 10–5 M of hydroxy compounds of lead is studied. With the compounds, the process rate passes through a maximum, whose potential E
m shifts in the negative direction and whose height drops with increasing pH. The pH dependence of E
m is linear, with the slope dE
m/dpH = –71 ± 5 mV, and correlates with that of the potential at which lead adatoms start to undergo desorption from the gold surface in alkali solutions. Without the compounds, the gold dissolution rate in alkali–cyanide solutions is independent of the solution pH at E < 0. Thus, the effect of the solution pH in this potential range is connected not with a direct participation of hydroxide ions in the anodic process but is of a secondary nature caused by the dependence of the region of adsorption of catalytically active lead adatoms on the hydroxide ion content in solution. 相似文献
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The depolarization of the gold electrodeposition in the presence of lead ions depends on their concentration and the duration of electrode contact with solution preceding a potential scan in an extremum fashion. At constant coverages of the gold surface by lead adatoms , the process rate depends on the overvoltage in accord with the Tafel equation. Effective values of the exchange current i
0 and transfer coefficient increase with from i
0 3 × 10–5 A cm–2 and = 0.23 in pure solutions to 3 × 10–4 A cm–2 and 0.53 at 0.4. The reaction order by cyanide ions is independent of and equals nearly –0.9. Effects of lead adatoms on the kinetics of cathodic and anodic processes are compared and the obtained data may be brought to conformance given that their mechanisms in pure solutions differ and converge in the presence of lead adatoms. 相似文献
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Kononov Yu. S. Pashkov G. L. Kholmogorov A. G. 《Russian Journal of Applied Chemistry》2003,76(7):1174-1175
Recovery of gold cyanide complexes was studied using sorbents prepared from Kansk-Achinsk lignite. 相似文献
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Yi ZHANG Ming Hua ZHOU Le Cheng LEI Institute of Environmental Engineering Zhejiang University Hangzhou 《中国化学快报》2006,17(4):541-544
In order to improve 4-CP degradation efficiency, a novel gas-liquid hybrid discharge (HD) reactor was developed. Removal of 4-CP with spark-spark discharge (SSD) was higher than that with spark-corona discharge (SCD). Amount of H2O2 and O3 produced with SSD were larger than that with SCD. ·OH formation was increased by the combination of H2O2 and O3. The contribution of ·OH (38 % formed by O3 conversion) oxidation on removal of 4-CP accounted for nearly 60 %. The other effects of ultraviolet radiation, intense shock waves and pyrolysis, played partial roles in about 40 % of removal rate. 相似文献
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采用放射性同位素198Au示踪法研究了伯胺N1923和TBP从碱性氰化液中萃取金(Ⅰ),考察了酸化率、水相pH值、萃取剂浓度等对萃取率的影响,以及NaOH对载金有机相的反萃作用。结果表明,TBP含量大于20%,酸化的N1923与KAu(CN)2摩尔比值在1:1时,金能够完全被萃取。载金有机相可采用0.lmol·L-1的Na0H溶液定量反萃。机理研究表明,伯胺和TBP萃取Au(CN)2-,符合BC类协同萃取机理。当金浓度大于10g·L-1时,在萃取有机相中形成纳米级的聚集体。 相似文献
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N1923从碱性氰化液中萃取金(Ⅰ)的研究 总被引:6,自引:0,他引:6
采用放射性同位素198Au示踪法研究了伯胺N1923和TBP从碱性氰化液中萃取金(Ⅰ),考察了酸化率、水相pH值、萃取剂浓度等对萃取率的影响,以及NaOH对载金有机相的反萃作用。结果表明,TBP含量大于20%,酸化的N1923与KAu(CN)2摩尔比值在11时,金能够完全被萃取。载金有机相可采用0.1mol·L-1的NaOH溶液定量反萃。机理研究表明,伯胺和TBP萃取Au(CN)2-,符合BC类协同萃取机理。当金浓度大于10g·L-1时,在萃取有机相中形成纳米级的聚集体。 相似文献
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《广州化学》2015,(4):13-17
在室温下采用微生物吸附―化学还原法从含金废水中快速回收金,考察了p H值、反应时间、表面活性剂溴化十六烷基三甲基铵(CTAB)用量、大肠杆菌(ECCs)用量、还原剂抗坏血酸(AA)用量对金回收效果的影响,并通过TG-DTG、SEM和EDX进行表征。结果表明:当p H值为3.2、CTAB用量为5.0 mmol/L、ECCs用量为0.5 g/L、AA用量为0.5 mmol/L、反应时间为60 min时,金回收效果最佳。TG-DTG、SEM和EDX图分析说明聚集沉淀物是由金纳米线包裹菌体形成复合材料,金的回收率为97.61%。该过程操作工艺简单、金回收率高,具有良好的应用前景。 相似文献
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Dr. Ana Sofia Varela 《Angewandte Chemie (International ed. in English)》2023,62(12):e202217395
The recovery of gold from wastewater is necessary from both environmental and economic standpoints. Metal–organic frameworks (MOFs) can serve as high-capacity and selective adsorbents, as shown in a recent work by Zhao and co-workers. Their novel three-dimension cationic framework goes further than selectively adsorbing AuCl4−. It also serves as a stable platform to transform adsorbed gold into an efficient catalyst for the electrochemical reduction of CO2. This work highlights the versatility of MOFs, which can serve as selective adsorbents and as a support for nanoparticle catalysts. 相似文献
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以某湿法铜业公司外排含铜废水为研究对象,系统考察了煤油-LIX984-CTMAB(十六烷基三甲基溴化铵)液膜体系对含铜废水中铜的分离。考察内容主要包括料液酸度、内相酸度、搅拌时间、LIX984用量、乳化液用量、乳化剂(CTMAB)用量、膜相和内相体积比。在最优条件下,铜离子的萃取率达到95%左右。 相似文献
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A. V. Kolesnikov A. D. Milyutina Yu. Sh. Ladygina V. A. Kolesnikov 《Russian Journal of Applied Chemistry》2018,91(7):1081-1089
Sorption extraction of anionic surfactants NaDDS and NaDBS on freshly formed iron(III) and aluminum(III) hydroxides and on a highly dispersed activated carbon of OU-B brand was experimentally studied. It was shown that NaDDS is the most fully sorbed on Al(OH)3 and OU-B, whereas on Fe(OH)3, the maximum sorption is observed for NaDBS. The electroflotation extraction of anionic surfactants and poorly soluble iron(III) and aluminum(III) hydroxides was examined and the influence exerted by the following factors (pH, nature of electrolyte, surfactant concentration) on the degree of extraction of these substances was analyzed. In addition, electroflotation extraction of OU-B in the presence on nonferrous metal hydroxides and surfactants of varied nature from aqueous solutions was performed. The results obtained were used to develop a technological scheme for electroflotation of complex-composition wastewater. 相似文献