熔炼法从失效汽车尾气催化剂中富集回收铂钯铑

采用火法熔炼技术对失效汽车尾气催化剂中铂族金属的熔炼富集进行了研究。主要考察捕集剂、还原剂、造渣剂等用量对铂钯铑综合回收率的影响。最佳熔炼工艺条件:反应时间4h、捕集剂Fe3O4用量为物料量的20%、还原剂用量9%、CaO用量40%、熔炼温度1 450℃,金属铂钯铑的综合回收率可达到97%以上。熔炼产物PGM-Fe合金的主要成分是单质铁,含量为91%~93%,铂族金属含量在4%~5%。     

贱金属富集废催化剂中铂族金属的研究

废催化剂是铂族金属的重要来源,采用火法冶炼是废催化剂中铂族金属富集的重要方法,高温下铂族金属与贱金属形成合金,通过载体造渣,达到富集铂族金属的目的。对铅、铁、铜三种贱金属富集铂族金属进行综述,介绍了三种金属富集的原理、工艺及发展,并对其优缺点进行了分析。     

Magnetic Concentration of Platinum Group Metals from Catalyst Scraps Using Iron Deposition Pretreatment

Spent automobile catalysts are the most important secondary source of platinum group metals (PGMs). However, effective recovery of PGMs from catalyst scraps is difficult because they are present in only small quantities as chemically stable substances. In this study, in order to improve the efficiency of the existing recycling processes, the authors experimentally investigated a novel physical concentration pretreatment process for PGMs using samples that simulate an automobile catalyst. In order to magnetically separate PGMs directly from the catalysts, ferromagnetic Fe was deposited on the PGM particles (or the porous catalyst layer) using an electroless plating technique. By using a plating bath containing sodium borohydride and potassium sodium tartrate as the reducing and complexing agents, respectively, Fe was successfully deposited on the sample without requiring complicated pretreatments such as sensitization and activation. After Fe deposition and subsequent pulverization, the PGMs could be extracted and concentrated in the form of magnetic powder using a magnet. The proposed magnetic concentration process was demonstrated to be feasible, and it has the potential to make the recycling of PGMs more efficient and environmentally friendly.     

Enhanced Dissolution of Platinum Group Metals Using Electroless Iron Deposition Pretreatment

In order to develop a new method for efficiently recovering platinum group metals (PGMs) from catalyst scraps, the authors investigated an efficient dissolution process where the material was pretreated by electroless Fe deposition. When Rh-loaded alumina powder was kept in aqua regia at 313 K (40 °C) for 30 to 60 minutes, the Rh hardly dissolved. Meanwhile, after electroless Fe plating using a bath containing sodium borohydride and potassium sodium tartrate as the reducing and complexing agents, respectively, approximately 60 pct of Rh was extracted by aqua regia at 313 K (40 °C) after 30 minutes. Furthermore, when heat treatment was performed at 1200 K (927 °C) for 60 minutes in vacuum after electroless plating, the extraction of Rh approached 100 pct for the same leaching conditions. The authors also confirmed that the Fe deposition pretreatment enhanced the dissolution of Pt and Pd. These results indicate that an effective and environmentally friendly process for the separation and extraction of PGMs from catalyst scraps can be developed utilizing this Fe deposition pretreatment.     

A Study on the Utilization of Magnetite for the Recovery of Platinum Group Metals from Chloride Solution

The recovery of platinum group metals (PGMs) from chloride solution using magnetite was investigated. The adsorption of platinum, palladium, and rhodium in chloride medium onto synthetic magnetite powders were studied at different pH conditions, contact time, sodium chloride concentrations, and initial Pt, Rh, and Pd concentrations. Platinum and palladium uptake by magnetite was at a maximum at pH 6–7, and pH 3–4 for rhodium after 24 h with 0.1 mol/dm³ sodium chloride at an initial PGM concentration of 0.05 mol/m³. A sorption mechanism for PGMs was discussed based on the results.     

废加氢催化剂还原熔炼回收有价金属试验

以石化行业重油精炼加氢脱硫过程中产生的废加氢催化剂为原料,采用还原熔炼工艺回收其中的有价金属。结果表明,在SiO2添加量40%、B2O3添加量10%、CaO添加量29%、Na2CO3添加量80%、冰铜添加量100%、褐煤添加量5%、CaF2添加量5%、1 450℃还原3h,渣计Mo、Co、Ni和V的回收率分别为98.54%、96.51%、99.47%和37.41%。     

Recovery and Marine Clay Stabilization of Heavy Metals Present in Spent Hydrotreating Catalysts

This paper presents the results of an investigation on the treatment of two industrial solid wastes produced by oil refineries in Singapore, namely Ni∕Mo∕γAl2O3 and Co∕Mo∕γAl2O3. Calcination at 500°C was effective in removing carbon and sulfur in both wastes followed by generation of heavy metal oxides. A two-stage leaching process was successful in removing 44% nickel, 77% cobalt, and 83% molybdenum. However, toxicity characteristic leaching procedure leaching tests for spent catalyst residues of Co∕Mo∕γAl2O3 and Ni∕Mo∕γAl2O3 after the two-stage leaching process showed that the concentration of Mo, Co, and Ni in the leachate exceeded the allowable limits. Finally, the residues, when subjected to an enhanced binder stabilization treatment with marine clay, produced a commercial-value brick made of up to 30% by weight spent catalysts. It is believed that stabilization can be achieved through either encapsulation whereby the clay forms a matrix around the heavy metals to prevent leaching or incorporation in which the heavy metals actually become part of the stabilizing matrix.     

Review of Recovery of Platinum Group Metals from Copper Leach Residues and Other Resources

Porphyry copper and mixed copper-gold sulfide deposits contain varying amounts of precious (gold and silver) and platinum group metals (PGMs). Currently, milling and froth flotation is the most common processing route for the treatment of high-grade base metal sulfide ores. During this process, the precious metals and PGMs are also concentrated and represent a possible opportunity for the beneficiation of these metals to increase the overall economic value of the ore. Although not yet commercialized, the high temperature pressure oxidation (POX) of copper concentrates provides an alternative processing route to traditional smelting technology. With increasingly aggressive air quality standards and rising upstream processing costs for smelting, hydrometallurgical processing options become progressively attractive. The treatment of POX residues for the recovery of precious metals has seen significant attention and multiple processing routes have been developed on various scales. Extraction and beneficiation of PGMs from copper concentrate POX residue has garnered significantly less attention and mechanistic questions remain to be answered. Based on a review of the processing options for PGM ores and concentrates, hydrometallurgical processing routes for the extraction of PGMs from copper concentrate POX residues are envisioned.     

Effective Dissolution of Platinum by Using Chloride Salts in Recovery Process

Platinum (Pt) is typically recovered by employing dissolution processes in aqueous solutions; however, these processes require a long processing time and considerable quantities of acids with strong oxidants owing to the high chemical stability of Pt. In order to develop an efficient dissolution process, we studied chlorination treatments for Pt prior to dissolution. Chlorination was carried out at 673?K to 873?K (400?°C to 600?°C) using copper(II) chloride (CuCl₂) as a chlorine source. While pure Pt was insoluble in hydrochloric acid (HCl(aq)), the entire Pt component of the treated sample dissolved in HCl(aq) under certain conditions. Therefore, the proposed method can be used as a new, environmental friendly Pt recovery process.     

用含钴废催化剂制取氯化钴和氧化铁红

研究了采用化学分离法从含钴废催化剂中回收氯化钴及氧化铁红。试验结果表明:所得氯化钴(CoCl2.6H2O)的纯度≥96%,钴回收率≥84%;氧化铁红(Fe2O3)纯度≥65%,铁回收率≥88%;试验工艺可行,经济效益明显。     

Recovery of Iron from Pyrite Cinder Containing Non-ferrous Metals Using High-Temperature Chloridizing-Reduction-Magnetic Separation

This study presents a new technique that uses high-temperature chloridizing -reduction-magnetic separation to recover iron from pyrite cinder containing non-ferrous metals. The effects of the reduction temperature, reduction time, and chlorinating agent dosage were investigated. The optimized process parameters were proposed as the following: CaCl₂ dosage of 2 pct, chloridizing at 1398 K (1125 °C) for 10 minutes, reducing at 1323 K (1050 °C) for 80 minutes, grinding to a particle size of 78.8 pct less than 45 μm, and magnetic field intensity of 73 mT. Under the optimized conditions, the Cu, Pb, and Zn removal rates were 45.2, 99.2, and 89.1 pct, respectively. The iron content of the magnetic concentrate was 90.6 pct, and the iron recovery rate was 94.8 pct. Furthermore, the reduction behavior and separation mechanism were determined based on microstructure and phase change analyses using X-ray powder diffraction, scanning electron microscope, and optical microscopy.     

从玻璃纤维池窑废耐火浇注料中回收提取铂和铑

以玻璃纤维行业生产的废耐火材料为原料,采用王水溶解、离子交换、溶剂萃取和萃淋树脂分离为主要方法回收纯铂铑,得到了良好的提取效果.结果表明,采用该工艺,铂铑的回收率可达90%以上,制得的海绵铂和铑粉的纯度均大于99.95%.     

从废弃锂离子电池中回收有价金属的技术

大量废弃锂离子电池会对环境造成污染,而且也造成资源浪费.近年来,从锂离子废旧电池中回收有价资源的研究发展很快.干法和湿法技术比较成熟,但存在能耗高、二次污染、资源回收率不高等问题.未来的研究方向是寻找一种更为合理、有效、清洁的金属回收和资源利用途径,而生物浸出技术有望充当这一角色.     

Recovery and Characterization of Nickel Oxalate and Oxide Obtained from Spent Methanation Catalysts

Metallurgical and Materials Transactions B - In this paper, hydrometallurgical extraction and characterization of nickel from spent methanation catalyst composed of components NiO, Al2O3, Fe2O3,...     

氨浸工艺从废旧锂电池中选择性回收有价金属

研究了碳酸氢铵-还原剂体系选择性浸出废旧三元锂电池中锂、镍、钴的过程。考察了浸出温度、碳酸氢铵浓度、还原剂的种类和浓度、固液比及浸出时间等对有价金属浸出率的影响,并通过XRD、SEM-EDS和FT-IR等表征方法对选择性浸出机理进行了初步探明。结果表明：在浸出温度80 ℃、浸出时间2.5 h、碳酸氢铵浓度2.5 mol/L、固液比50 g/L、还原剂亚硫酸钠浓度0.6 mol/L的条件下,锂、镍、钴的浸出率分别为96.86%、96.36%、93.43%,而锰几乎不被浸出。碳酸氢铵-亚硫酸钠还原浸出体系可以实现从废旧三元锂电池材料中高效、选择性回收锂、镍和钴。     

从废钼催化剂中回收有价金属试验研究

研究了采用空气氧化、氢氧化钠浸出、硝酸酸化工艺从废钼催化剂中回收 Mo、Co、Ni等有价金属。试验结果表明：在空气流量30 L/min、氢氧化钠加入量为金属Mo理论耗量1倍、浸出温度85℃条件下,钼浸出率达99．8％;碱浸渣用硝酸酸化、双氧水除铁,双氧水加入量为铁理论量的2～3倍,反应温度70℃;滤液用NaO H溶液调p H为9．5,镍、钴以氢氧化物形式沉淀,酸溶后,用P507萃取剂萃取分离钴、镍。该工艺采用空气氧化,避免了传统焙烧工艺MoO3的挥发损失;用NaOH浸出Mo ,生产成本降低,工艺流程简单,金属回收率较高。     

失效载体催化剂回收铂族金属工艺和技术

介绍国内外失效载体催化剂回收铂族金属的3种工艺技术：火法、湿法和火-湿法联合工艺，并作简要评论，     

废旧磷酸亚铁锂正极材料湿法回收研究进展

随着磷酸亚铁锂锂离子电池市场大幅度增长,大量磷酸亚铁锂电池需要回收。以废旧磷酸亚铁锂正极材料湿法回收中的氧化、浸出和磷酸铁沉淀为重点,以锂盐和磷酸铁为目标产物,介绍国内外湿法回收废旧磷酸亚铁锂正极材料的研究进展。     

废催化剂中铂族金属分析的取样研究

对各种含钯废催化剂取样方法的研究表明，对于大量的桶装废料，采用管枪取样法对获得代表性的样品是最适用的。同时给出了几种废钯催化剂中钯含量的正确分析结果。     

提高废三元催化剂铂族金属回收率工艺研究

首次采用NaHB4预还原,NaClO2-HCl-NaCl为浸出剂,氯化浸出法提取废三元催化剂中铂族金属,经分离提纯,铂回收率达到95.9%,钯回收率达到96.2%,铑回收率达到87%。此方法也适合用回收其他废催化剂中铂族金属。