用有机酸（Ar（OH）3COOH）从废定影液中回收银

介绍了用有机酸（Ar(OH)3COOH)从废定影液中还原银的方法及工艺条件,试验结果表明,用有机酸（Ar(OH)3COOH)从废定影液中还原银,银还原率为99.20%,总回收率为94.5%,回收的银粉（片）中银的质量分数为97.43%。     

用连二亚硫酸钠（Na2S2O4）从废定影液中提银

以还原后废定影液中残余银的质量浓度、银粉质量（银粉的品位）以及废定影液中Na2S2O3的质量浓度的变化为考察指标,研究了用连二亚硫酸钠（Na2S2O4）作还原剂提取废定影液中的银的效果,以及废定影液的再生情况.结果表明,这种提银方法不但能够得到较高纯度的金属银和银质量浓度很低的废定影液（p（Ag）＜0．05g／L）,而且还可以使定影液中主要成份Na2S2O3的质量浓度升高,使废定影液得到再生。     

用葡萄糖还原法回收废定影液中银

本文讨论了用酒石酸水解蔗糖制得葡萄糖还原液,再用此还原糖液还原废定影液中的银;采用正交实验方法,分析不同因素、不同位级对银回收率的影响,找出得到较高回收率的工艺条件。     

多种废液、废料中回收银

本文主要对废液、废料、废定影液、废照相软片、废氯化银、废的银触头、银合金、银镀件、焊剂等材料中提取银做了研究,提出了硫化钠沉淀分离、锌粒还原、脱胶、烘干、焙化、电解等方法。从各种废液、废料中收回银,对集体和国家都具有重要意义。     

沉淀法回收废定影液中的银

以过氧化氢、磷酸、硫酸、盐酸、甲酸、乙酸为沉淀剂,将废定影液中的银以硫化银的形式沉淀出来,经熔炼后得到金属银。试验考察了沉淀剂的种类、30%过氧化氢用量、陈化时间、加料顺序对银回收率的影响,其结果表明,滴加30%过氧化氢至淀粉-碘化钾试纸变蓝、陈化24 h条件下回收废定影液中银的效果最好,银回收率达98%以上。过氧化氢沉淀回收废定影液中的银,无有害气体产生,不产生二次污染,是对环境友好的绿色沉淀剂。     

从废定影液中回收银的电位—pH图分析

用电位ｐＨ图分析了从废定影液中回收银所使用的各种方法，指出了各种方法应控制的条件及可能出现的问题，认为连二亚硫酸钠还原法是比较好的方法，它既能得到较高质量的银又能使废定影液再生     

废定影液提银技术研究进展

文中综述了从洗相废定影液中回收银采用的物理法、化学法及生物法,分析了各种处理方法的优缺点以及废液再利用的途径。从经济、环保的角度出发,提出了采用金属置换法与活性炭吸附法联合回收废定影液中的银,更为合理、有效。     

4-(3-吡啶基)-2-巯基咪唑修饰碳糊电极阳极溶出伏安法测定痕量银

报道了采用化合物4-(3-吡啶基)-2-巯基咪唑(PMI)修饰碳糊电极测定痕量银的阳极溶出伏安法。在0.1 mol/L的HNO3中,Ag+可以富集于PMI修饰电极表面,将介质交换至含I-的0.02 mol/L硫酸溶液中,-0.20 V还原30 s后再进行阳极溶出伏安测定,可以获得灵敏的银阳极溶出峰。一次导数峰电流与Ag+在8.0×10-10~4.0×10-6mol/L浓度范围内呈线性关系,检出限可达5.0×10-10mol/L(S/N=3)。采用本法不经过预分离,对成分复杂的定影液废液和锌合金等样品进行了直接测定,测定的回收率为92%~105%。     

感光废液中银综合回收方法

废定影液中含有大量的贵金属银，回收其中的银不仅可以避免环境污染，而且可以节约资源，具有重要的经济价值。本文介绍了几种不同的银回收方法，简要论述了各种方法的优缺点。并指出电解法将广泛应用于回收废定影液中的银。     

置换法从废定影液中回收银的研究

研究了用金属铁作置换剂从洗相废定影液中回收银的工艺及其影响因素;确定了最佳置换条件为:铁粉用量3.8 g/L,pH值 5.5,温度40 ℃,搅拌速度1 440 r/min,搅拌时间30 min.在该试验条件下,银的置换率达到95.6 %,回收1 kg银的成本为58.6元.     

Extraction of chromium (III) from spent tanning baths

Extraction of chromium(III) from a model spent tanning bath of the leather industry has been investigated using ammoniated and non-ammoniated di(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex® 272). Chromium extraction of 95% by 15% (v/v) D2EHPA, 10% (v/v) isodecanol in kerosene and 86.1% by 15% (v/v) Cyanex® 272, 10% (v/v) p-nonylphenol in kerosene was obtained at equilibrium pH values of 4.0 and 5.0, respectively. The separation of small amounts of iron (III) and aluminium (III) present in the solution along with the Cr(III), was also examined and it was found that Cyanex® 272 was a better reagent than D2EHPA. The slow kinetics of extraction and stripping observed in the case of AI(III) was advantageous for its separation from Fe(III) at low pH values. Difficulties faced in the stripping of loaded metals were also studied because only about 80% chromium recovery by 8 M HCl was obtained from both solvents. The incomplete stripping of the metal may be a result of the formation of a stable species in the organic phase and needs further investigation. The Cr(III) can be recovered as chloride from the strip liquor and recycled for retanning purposes.     

采用漂定废液回收废感光胶片中银的方法研究

研究了利用彩印漂定废液回收废感光胶片中银的方法.废漂定液在pH＝8～9时,用KBH4还原回收银,回收银后的漂定液通过补加主要成分可作为浸取剂浸出废感光胶片上的银.该方法银的回收率高,废漂定液可以多次循环使用.     

Solvent extraction-separation of La(III), Eu(III) and Er(III) ions from aqueous chloride medium using carbamoyl-carboxylic acid extractants

N,N-dibutyldiglycol amic acid(HLI) and N,N-dioctyldiglycol amic acid(HLII) were synthesized and characterized by conventional spectroscopic methods. These molecules were examined as extractants for extraction-separation of La(III), Eu(III) and Er(III), as representative ions of light, middle and heavy rare earths, from aqueous chloride solutions. The analysis of the extraction equilibria revealed that the extracted species of lanthanum and europium ions by both of the extractants had a 1:3 metal to ligand ratio. It was suggested that erbium ions were extracted into the organic phase via the formation of Er(LI or II)2Cl complexes. The effect of the organic diluents on the extraction-separation efficiency of the studied rare earths by HLI and HLII was investigated by comparing the results obtained in dichloromethane and carbon tetrachloride. Regardless to the diluent used, the order of selectivity presented by the investigated extractants was Er(III)Eu(III)La(III). It is noteworthy that, a significant enhancement in separation of the studied rare earths by the extractants was achieved in their competitive extraction experiments with respect to that obtained in single component extraction experiments. Applicability of the extractants for the removal of rare earth ions from spent Ni-MH batteries was tested by removal of La(III), Eu(III) and Er(III) ions from simulated leach solution of such batteries.     

Recovery of Cr(III) from Tannery Spent Chrome Liquor for Reuse

This paper embodies details on the extraction behavior of Cr(III) along with Al(III), Fe(III), Mg(II), Mn(II), Co(II), Ni(II), and Cu(II) from hydrochloric acid media employing the Cyanex 301-toluene system. All of these metals, except Cr(III), Mg(II), and Mn(II), are extracted into the organic phase. This property of the extractant has been used to separate Cr(III) from the binary mixtures. The partition data have been extended onto spent chrome liquor, and this waste has been treated in such a manner so that it becomes suitable for use in trivalent plating baths. The hydrolytic stability and recycling capacity has been reported. Because the concentration of Cr(III) in the waste is much lower than that required for chromium depositions in Cr(III) plating baths, a concentration step using MgO as a precipitating agent has been appended. To summarize, this paper envisages a new approach to tannery waste management that focuses on treating spent chrome liquors using a solvent extraction technique in such a manner that the waste becomes suitable for use in trivalent plating baths. This would not only help abate pollution but also recover the metal in a pure form.     

电感耦合等离子体原子发射光谱法测定铂铼废催化剂中铼

采用高温灼烧可除去铂铼废催化剂中碳、硫和有机物,但铼挥发损失严重。根据小于300℃时,高氯酸冒烟可除去碳、硫和有机物且铼基本不挥发损失这一原理,建立了采用硝酸-高氯酸消解样品,电感耦合等离子体原子发射光谱法(ICP-AES)测定铂铼废催化剂中铼的方法。确定的实验条件为:样品量为0.15g,加入2.0mL硝酸、1.0mL高氯酸, 260~290℃加热至刚冒烟;再加入2.0mL硝酸,加热至刚冒烟;重复2次至试液清亮;加入10.0mL盐酸,转入100mL容量瓶中,定容摇匀,于分析线Re 221.426nm处,ICP-AES测定铼。铝(Ⅲ)、铂(Ⅳ)、铁(Ⅲ)等共存离子不干扰测定。将实验方法用于1个铂铼废催化剂试验样品、4个铂铼废催化剂实际样品中铼(639.4~5854.8g/t)的测定,试验样品的测定值与推荐值基本一致,结果的相对标准偏差(n=11)为0.17%~0.63%,加标回收率为98.8%~100.3%。     

Recovery of rare earths from spent FCC catalysts by solvent extraction using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester(EHEHPA)

A process to recover rare earth(RE) metals from spent fluid catalytic cracking(FCC) catalysts by solvent extraction was studied, using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester(EHEHPA or P507). The recovery process involved three steps:(1) leaching REs(mainly lanthanum and cerium);(2) solvent extraction by applying saponified P507-kerosene system;(3) stripping. Experiments to assure optimal operating conditions were conducted. Results indicated that RE metals could be recovered effectively from spent catalyst with saponified P507-kerosene-HCl system. At room temperature of 25 oC, 10 g spent catalyst with 110 m L of HCl(1 mol/L) could achieve a leaching efficiency of 85%. For extraction, initial pH value of 3.17, organic/aqueous ratio(O/A ratio) of 2:1 with an extractants' saponification rate of 20% could obtain 100% efficiency. In the stripping process, 1 mol/L HCl with O/A ratio of 1:1 led to a stripping efficiency of 96%. In the present study, RE metals from spent FCC catalysts were effectively recovered, which avoided wasting a large amount of RE resources. It provides a theoretical support for commercial recycling of RE resources.     

Selective arsenic-fixing roast of refractory gold concentrate

A novel pretreatment technique suitable for gold extraction from refractory ores was developed. The technique was based on selective arsenic fixing, using a fixing agent in the conventional two-stage roast. As in the existing fixing roast, more than 92 pct of the arsenic was retained in the calcine, using sulfate and lime as selective arsenic-fixing agents in fixing roast process. The arsenate retained in the leaching residue was found to be stable. The selective fixing of arsenic allowed about 80 pct of the sulfur to be recovered for sulfuric acid production. Compared to the existing fixing roast, the amount of fixing agent added was reduced, accompanied by a reduction in solid-waste generation. Integrated in a two-stage roast under the optimal operating conditions identified, the new process resulted in a gold recovery of 89 to 91 pct from a typical refractory gold ore containing a substantial amount of pyrite, arsenopyrite, antimony, and carbonaceous and organic carbons.     

Pathogenesis and treatment of primary and secondary recurrent erosion (author's transl)

Out of 72 cases of recurrent erosion (RE) a trauma was given as the cause in 61. In 11 cases it occurred spontaneously. Primary recurrent erosion develops predominantly after corneal injury by foreign bodies of organic origin. Finger nail injuries are the most common cause of RE (in erosions 2%, in recurrent erosions 20%). The composition and surface structure of the injuring body may well be of far greater importance with regard to the statistical incidence of primary RE than the mechanism of the trauma (tangential bruising). In RE there may be a neurodystrophy (situated below the centre, organic foreign bodies). In addition to the frequently encountered primary RE (usually after injury by an organic foreign body) there is a "secondary" RE, less often seen, presumably hereditary, and bilateral, in superficial corneal and epithelial dystrophies. We have achieved good therapeutic results by doing a corneal abrasion and inducing a circumscribed inflammation (with lactic acid).