Furnace for processing scrap and waste products

The company METPROMMASh has been developing and introducing metallurgical technologies and equipment for the nonferrous metals sector for more than 10 years. A particular focus of the company has been the construction of furnaces for recycling aluminum-and copper-bearing scrap and waste products. Furnaces made by METPROMMASh are currently being used by shops and factories that recycle nonferrous metals, these furnaces being suited for recyclers that process from 100 to 2000 tons of scrap a month. The furnaces are built on the grounds of the customer’s scrap storage facility after the most efficient location has been chosen for the metallurgical and auxiliary equipment, the system for handling the movement of materials has been planned, and the feasibility of further processing of the recycled metal has been determined. Depending on the composition of the metallurgical equipment, a recycling complex can be built in a minimum of four months on an area 300 m² or larger. __________ Translated from Metallurg, No. 4, p. 45, April, 2006.     

Monitoring of less-common residual elements in scrap feeds for EAF steelmaking

The steel scrap quality is classified according to the amount of residual elements. However, there is a limited analysis of some of the less common residual elements such as antimony (Sb), tungsten (W), cobalt (Co), nickel (Ni) and molybdenum (Mo) mixed with steel scrap received by steel plants. This paper reports a historical analysis of these elements in the steel compositions from two steel plants, located in different regions, during 2011 to 2018, analysing around 21000 heats. The concentration of W and Sb dropped by 0.002%, due to the increasing recovery of non-ferrous metals from mixed scrap. It was found that the calibration and maintenance of the spectrometer used to analysis had a direct impact on the results. The presence of Sb, W and Co in the steel indicates contamination from other materials, since 80% of the use of these elements is in applications associated with non-ferrous materials. This is the first analysis of these elements in steel scrap reported the literature and the conclusion of the study is that more attention should be paid to monitor less common residuals elements, because analysis of these elements can provide information about the quality of the metal scrap.     

Inflation Cycles and Metals Prices

A leading index of inflation, developed and published monthly by the Center for International Business Cycle Research at Columbia University, has been designed to anticipate swings in broad measures of inflation such as the consumer price index. It generates signals indicating when the rate of inflation is likely to move up or down. Since metals prices are sensitive to the same types of economic factors that influence the overall inflation rate, we have examined the behavior of metals prices during intervals marked off by the signal dates. Between 1949 and 1986 the producer price index for metals and metal products moved up at an average annual rate of 6.7% when the leading index signaled an upswing, compared to a 1.7% rate during the remaining intervals. Aluminum scrap prices rose at a 15% average rate during the upswing signals but declined at an 11% rate otherwise. Copper scrap and zinc prices behaved similarly. The leading index of inflation appears to be a promising tool for forecasting short-run trends in metals prices.     

废铝合金回收处理及再利用技术（续）

通过以上综合技术的有机融合，在废铝合金回收处理环节大幅度地减少和降低了金属烧损，把铝资源的回收提到了一个全新的水平。     

热轧工艺对不锈钢包覆铁屑复合板性能的影响

 为了研究不锈钢与铁屑的复合性能,采用热轧方式,利用金属固态回收理念制备不锈钢包覆铁屑复合板。通过金相显微镜对不锈钢与铁屑的接触界面进行分析,采用剪切试验及拉伸试验对复合板进行性能测试,研究了热轧工艺条件对不锈钢和铁屑复合性能的影响。研究结果显示,较大单道次压下量仍未使两金属复合的原因是大压下量并不能使铁屑间孔洞完全消失,铁屑在宽展方向仍有流动空间。但当单道次压下量较小而累积压下量达到17 mm时,试件剪切强度为225 MPa,已达到国家规定。因此,一定的累积压下量是影响不锈钢与铁屑复合的关键因素之一。在铁屑中添加石墨粉可以改善材料的力学性能,提高轧后试件的抗拉强度和剪切强度,但会降低其伸长率。     

杂铜阳极泥回转窑氧化焙烧酸浸工艺研究

采用回转窑氧化焙烧—酸浸工艺回收杂铜阳极泥金属铜,研究了不同试验条件对铜浸出率的影响。结果表明:在氧化焙烧温度700℃、焙烧时间20 min、原料粒度-5 mm、空气流量0.5 L/min的条件下,铜浸出率高达97.10%,镍浸出率>90%,大部分铅、锡、锑、铋及贵金属金、银、钯残留在浸出渣中,可以作为后续提取有价金属及贵金属的原料。     

Computer-munching microbes: metal leaching from electronic scrap by bacteria and fungi

Microbiological processes were applied to mobilize metals from electronic waste materials. Bacteria (Thiobacillus thiooxidans, T. ferrooxidans) and fungi (Aspergillus niger, Penicillium simplicissimum) were grown in the presence of electronic scrap. The formation of inorganic and organic acids caused the mobilization of metals. Initial experiments showed that microbial growth was inhibited when the concentration of scrap in the medium exceeded 10 g L⁻¹. However, after a prolonged adaptation time, fungi as well as bacteria grew also at concentrations of 100 g L⁻¹. Both fungal strains were able to mobilize Cu and Sn by 65%, and Al, Ni, Pb, and Zn by more than 95%. At scrap concentrations of 5–10 g L⁻¹, Thiobacilli were able to leach more than 90% of the available Cu, Zn, Ni, and Al. Pb precipitated as PbSO₄ while Sn precipitated probably as SnO. For a more efficient metal mobilization, a two-step leaching process is proposed where biomass growth is separated from metal leaching.     

Ferrous scrap yields powders for PM & MMCs

The increasing environmental problem posed by the dumping of ferrous scrap material in Greece has inspired a programme at the National Technical University of Athens, investigating the recovery from scrap of metals in the form of powders. Prof. A.K. Moutsatsou and V.G. Karayannis of the Laboratory of Inorganic and Analytical Chemistry explain the basis of their hydrometallurgical recovery process and outline investigations to demonstrate the potential of the powders for use in PM and MMCs.     

Metal vapor treatment for enhancing the dissolution of platinum group metals from automotive catalyst scrap

A new process for dissolving platinum group metals (PGMs) from automotive catalyst scrap using metal vapor was proposed. To improve the PGMs dissolution ratio from scraps, vapor of reactive metals (R), such as magnesium (Mg) or calcium (Ca), was reacted with the automotive catalyst scrap in a closed stainless steel vessel at 1173 K for 3 hours. Under these experimental conditions, Mg and Ca vapor was supplied to the entire body of catalyst scrap. After the reactive metal treatment, the specimens were crushed and dissolved in aqua regia at 323 to 333 K for 1 hour. The PGMs dissolution ratios were improved after the reactive metal treatment, and the dissolution ratios reached 88 pct in Pt, 81 pct in Pd, and 72 pct in Rh, while they were 77 pct in Pt, 69 pct in Pd, and 38 pct in Rh without the treatment. Even when the specimens were dissolved in aqua regia without heating, the PGMs dissolution ratios from the catalyst scrap after reactive metal treatment showed high values, 78 pct in Pt, 74 pct in Pd, and 57 pct in Rh at a maximum. These results show that the reactive metal treatment is effective for the recovery of PGMs from automotive catalyst scrap.     

A review of the recycling of rare earth metals

Although rare earth metals are more abundant than their name would indicate, disruptions of their supplychain have occurred recently, and it is no surprise thatthe US Department of Energy (DOE) and the European Union (EU) Commission have listed several of them as critical for their role as materials essential for a clean society. This paper briefly reviews the major uses for rare earth metals and identifies the potential sources of scrap for recycling. The paper then describes the various processes developed to recycle rare earth-containing scraps, such as spent Ni-metal hydride (MH) batteries, magnets, catalysts, polishing powders and phosphors, with case studies taken from industrial practice and research work. The success of recycling efforts depends not only on adequate technical advancements but also requires the overcoming of non-technical challenges comprising, among others, logistics (collection, transportation), and an appropriate political and legal framework.     

积极开发和有效利用再生资源促进有色金属工业可持续发展

20世纪70年代以来,随着世界经济持续发展,全球环境问题日益突出,再生资源的回收和利用越来越受到世界各国的关注和重视。本文阐述了发展再生有色金属产业的重要意义,分析了我国再生有色金属产业的发展现状和存在的问题,提出了对增强我国再生有色金属产业整体竞争实力的对策和建议。     

Advanced Review on Extraction of Nickel from Primary and Secondary Sources

In this review, resources of nickel and status of different processes/technologies in vogue or being developed for extraction of nickel and associated metals from both primary and secondary resources are summarized. Nickel extraction from primary resources such as ores/minerals (sulfides, arsenides, silicates, and oxides) including the unconventional one viz., the polymetallic sea nodules, and various secondary resources has been examined. Though sulfide ores after concentration are generally treated by the pyro-metallurgical route, most processes for lateritic ores deal with either the acid leaching at ambient temperature and pressure, or high pressure, and a few based on the microbial treatment and owing to the extensive research on laterites, a special emphasis is put forth in this review. Prominent sources that are covered in some detail include the solid wastes like spent batteries viz., end-of-life nickel-cadmium (NiCd) and nickel metal hydride (NiMH), spent catalysts, and spent/scrap superalloys, and liquid wastes such as copper bleed stream and electroplating effluents. In particular pre-treatment of the spent nickel-based batteries, leaching of metals from the electrode materials in different lixiviants, besides separation/solvent extraction of nickel/other metals from the leach liquors, are highlighted.     

臭氧在金、银等金属浸出方面的应用

综述了臭氧在金、银等金属浸出方面的应用与研究状况,臭氧可用于难浸金矿石的预处理,用于从矿石、精矿、尾矿及废料中强化浸出贵金属.指出臭氧在含碳金矿石、含铜金矿石预处理方面有很好的应用前景.     

废钨钛钴硬质合金中有价金属的回收

叙述了从废钨钛钴硬质合金中回收有价金属的工艺和原理。采用先热浓盐酸溶解,再焙烧、浸出、水解、结晶和还原等方法,可分离回收金属,制取金属钨粉、钴粉和金属钛。     

废钨钛钻硬质合金中有价金属的回收

叙述了从废钨钛钴硬质合金中回收有价金属的工艺和原理。采用先热浓盐酸溶解，再焙烧、浸出、水解、结晶和还原等方法，可分离回收金属，制取金属钨粉、钴粉和金属钛。     

Continuous oxygen steelmaking with copper-, tin-, and zinc-contaminated scrap

In the context of a new zero-gas-emission process for continuous oxygen steelmaking, desorption of copper, tin, and zinc from liquid scrap are modeled. Additive diffusional-resistance concepts show that zinc elimination at atmospheric pressure is entirely straightforward. For copper and tin, a reduced pressure (2.5 mbar) and a relatively high temperature (1780 °C) are preferred. Sulfur must be added above the stoichiometric requirements to volatilize tin sulfide. Copper elimination by physical desorption is completely predictable, but with tin, interfacial chemical kinetics may possibly exert an influence. Based on exclusive transport control and the currently available pumping capacity for vacuum degassing steel, the engineering feasibility of refining continuously melted steel scrap is established. Dimensions are estimated for producing 2 Mtpa of steel with a scrap-to-virgin iron ratio of 3 to 1. Electrical conductive heating is required to raise the liquid-scrap temperature toward the limits imposed by current refractories. With the proposed new technology, copper, tin, and zinc are all recovered as by-product metals. Pretreatment of steel scrap is not advocated, other than simple physical segregation at the source.     

铁硅石代替钢屑冶炼FeSi75的试验研究

针对近年来铁合金冶炼原料钢屑短缺的问题,提出利用一种铁硅石代替或部分代替钢屑冶炼硅铁。文章主要论述利用该铁硅石代替钢屑在小型矿热炉上进行连续冶炼FeSi75的试验过程,冶炼硅铁试验取得成功,分析结果可知此工艺与原工艺冶炼相比具有一定的综合经济效益和应用前景。     

A356熔炼过程中Ca和Sr质量分数的变化规律及预报模型

Ca和Sr是铸造铝硅合金中最有效的变质元素,一般在浇铸前以中间合金的形式加入.然而在废杂铝熔铸再生工业中,原料中常含有微量的Ca和Sr,预控它们在熔炼过程中的含量变化是它们再利用的前提.本文以工业A356铸锭为原料,实验研究了熔炼温度和保温时间对Ca和Sr质量分数变化规律的影响.结果表明:Ca和Sr质量分数随着保温时间延长均呈Exp3P2规律下降,且随熔炼温度升高质量分数下降速率均逐渐提高.根据热力学和动力学分析可知,在废杂铝熔炼再生过程前期主要发生[Ca]和[Sr]与熔体中的氧发生氧化反应生成CaO和SrO,这些氧化物又会与Al₂O₃反应生成Al₂O₃·6CaO和Al₂O₃·SrO,经扒渣操作后Ca和Sr质量分数下降.在熔炼中后期,[Ca]和[Sr]以扩散至熔体表层还原Al₂O₃的方式使它们的质量分数降低.计算得出在660~740℃熔炼A356合金时Ca和Sr氧化反应的表观活化能分别为182.6 kJ·mol-1和117.8 kJ·mol-1,两者均受化学反应过程控制.根据Ca和Sr质量分数的变化规律建立了它们的质量分数预报模型,经生产验证表明预报误差均小于10%,可用于预报废杂铝熔炼再生过程Ca和Sr的质量分数.      

Ultimate Deoxidation Method of Titanium Utilizing Y/YOCl/YCl3 Equilibrium

Metallurgical and Materials Transactions B - Deoxidation methods of titanium (Ti) scrap and Ti powder have become increasingly important in recent years. Some rare earth (RE) metals with strong...     

世界再生金属生产现状与趋势

介绍了世界废钢铁、再生铝、再生铜、再生铅锌、再生贵金属等的生产现状,指出了再生金属产业的广阔前景。