The availability of primary nickel from the market economy countries

The US Bureau of Mines has determined the potential availability of nickel from 36 deposits or districts in 16 market economy countries (MECs). More than 95% of production in MECs was analysed. The study indicates the quantity of nickel available in resources and potential annual production at net production costs and on a total cost basis with a 0% and a 10% discounted cash flow rate of return (DCFROR). The properties included in this study contain approximately 33 million tonnes of recoverable nickel. About 26 million tonnes of nickel is potentially recoverable from nickel laterite deposits, of which 4.5 million tonnes can be produced at $2.50/lb or less with a 0% DCFROR. Approximately 7 million tonnes of nickel is potentially recoverable from nickel sulphide deposits of which about 6.3 million tonnes could be produced at $2.50/lb or less at a 0% DCFROR. Sensitivity studies indicate that the total cost of producing nickel from laterite deposits is most sensitive to increases in energy costs, and that the total costs of producing nickel from sulphide deposits is most sensitive to increases in labour costs and by changes in byproduct revenues.     

我国南方某城市垃圾焚烧飞灰特性及固化/稳定化处置实验

我国南方某城市主要采用焚烧法处理生活垃圾,已建7个焚烧厂日产生飞灰量为101.62 t/d。文章分析了各个垃圾焚烧厂飞灰的化学组成和重金属浸出毒性,其主要成分为CaO、SiO2、MgO、Al2O3、Fe2O3、Na2O、SO3和Cl,所有焚烧飞灰都有至少一种重金属浸出浓度超标,属于危险废物。在飞灰处置出路亟待解决的背景下,实验探讨了飞灰稳定化工艺,结果表明10%的水泥添加量可以使飞灰中超标重金属(Cd、Pb和Zn)的浸出浓度满足危险废物鉴别浓度限值和安全填埋场入场浓度限值。同时,通过人体健康风险评价分析了飞灰豁免管理的可行性,并对近期和远期该城市焚烧厂飞灰的处理处置及管理提出建议。     

Leaching characteristics of solid wastes from thermal power plants of western Turkey and comparison of toxicity methodologies

Use of lignite in power generation has led to increasing environmental problems associated not only with gaseous emissions, but also with the disposal of ash residues. In particular, use of low quality coals with high ash content results in huge quantities of both fly and bottom ashes to be disposed of. A main problem related to coal ash disposal is the heavy metal content of the residue. In this regard, experimental results of numerous studies indicate that toxic trace metals may leach when fly and bottom ashes are in contact with water. In this study, fly and bottom ash samples obtained from thermal power plants, namely Yenikoy, Kemerkoy and Yatagan, located at the southwestern coast of Turkey, were subjected to toxicity tests such as the extraction (EP) and toxicity characteristic leaching (TCLP) procedures of the US Environmental Protection Agency (USEPA) and the so-called 'Method A' extraction procedure of the American Society of Testing and Material (ASTM). The geochemical composition of ash samples showed variations depending on the coal burned in the plants. Furthermore, the EP, TCLP and ASTM toxicity tests showed variations such that the ash samples were classified as 'toxic waste' based on EP and TCLP results whereas they were classified as 'non-toxic' based on ASTM results, indicating test results are pH dependent. When the extraction results were compared with the chemical composition of water samples obtained in the vicinity of the thermal power plants, it was found that the results obtained using the ASTM procedure cannot be used to predict subsurface contamination whereas the EP and TCLP procedures can be used.     

The automobile as a renewable resource

The present system which has led to a high rate of recovery of the ferrous and non-ferrous metals from the obsolete automobile processed by shredding is described. Projections of the potential resource recovery from the non-metallic components of the shredded automobile are presented along with a detailed account of the current research and development programme directed toward such recovery.     

The leaching characteristics of selenium from coal fly ashes

The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results for different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbituminous coal ashes at any pH. However, Se(IV) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbituminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO3* and SeO3 2* were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.     

Cement and concrete flow analysis in a rapidly expanding economy: Ireland as a case study

A national material flow model for concrete, the most popular construction material in Ireland, was developed based on the framework of material flow analysis. Using this model the Irish concrete cycle for the year 2007 was constructed by analysing the material life cycle of concrete which consists of the three phases of: production (including extraction of raw materials and manufacture of cement), usage (ready-mix and other products) and waste management (disposal or recovery). In this year, approximately 35 million metric tonnes of raw materials were consumed to produce 5 million metric tonnes of cement and 33 million metric tonnes of concrete. Concrete production was approximately 8 metric tonnes per capita. By comparison, the concrete waste produced in that year was minimal at only 0.3 million metric tonnes. Irish building stock is young and there was little demolition of structures in the year of study. However this build up of construction stock will have implications for the future waste flows when the majority of stock built in the last decade (43% of residential stock was constructed in the last 15 years) reaches its end of life.     

生物沥滤污泥重金属污染的潜在生物毒性评价

采用沉积物质量基准法(SQGs)和Hakanson指数法对沥滤前后城市污泥中重金属的潜在生物毒性进行了定性和定量的评价,结果表明氧化亚铁硫杆菌(A.ferrooxidans菌)对Cu、Cd的脱毒作用优于氧化硫硫杆菌(A.thiooxidans菌)。沥滤后污泥的综合潜在生态危害指数均能下降91.0%以上,且A.ferrooxidans菌沥后污泥的潜在生物毒性最弱,其综合潜在生态危害指数为84.75,是生物沥滤去除城市污泥重金属工程应用的适合菌种。     

Risk explicit interval linear programming model for long-term planning of vehicle recycling in the EU legislative context under uncertainty

With the number of vehicles expected to increase to 1.85 billion by 2030 and the scrap generated from end-of-life vehicles (ELVs) expected to be 3.71 billion tonnes, there is a strong motivation to properly process the flow of these materials. The EU Directive on end-of-life vehicles (EU ELV Directive) aims to increase recovery and recycling rates of ELVs in order to reduce waste and improve environmental performances. Long-term optimization planning of vehicle recycling is increasingly important. However, there is a lack of research of uncertainties in the vehicle recycling system, none of the previous studies analyzed the linkage and trade-offs between decision risk and system performances, and no previous research was reported on interval-based programming for vehicle recycling planning problem. In order to meet the imposed eco-efficiency quotas, maximize system profit and minimize decision risk, and at the same time fill the identified research gaps, a risk explicit interval linear programming model for optimal long-term planning in the EU vehicle recycling factories was developed. It can create optimal plans for procuring vehicle hulks, sorting of generated material fractions, allocation of sorted waste flows and allocation of sorted metals for desired value of the system aspiration level. A numerical study demonstrated the potentials and applicability of the proposed model. Vehicle recycling factories aim at reaching the highest possible level of quantity and quality of sorted metal flows. The future eco-efficiency quotas will not endanger their business. The success of the final phase of implementation of the EU ELV Directive is not jeopardized, because even the future eco-efficiency quotas were reached in all created test problems. Quantity of land-filled wastes will be radically reduced after January 1, 2015. The model results and trade-offs would be valuable for supporting the EU vehicle recycling factories in creating optimal long-term production strategies and reducing the risk for uncertain situations.     

Linking energy scenarios with metal demand modeling–The case of indium in CIGS solar cells

Some renewable energy technologies rely on the functionalities provided by geochemically scarce metals. One example are CIGS solar cells, an emerging thin film photovoltaic technology, which contain indium. In this study we model global future indium demand related to the implementation of various energy scenarios and assess implications for the supply system. Influencing parameters of the demand model are either static or dynamic and include technology shares, technological progress and handling in the anthroposphere. Parameters’ levels reflect pessimistic, reference, and optimistic development. The demand from other indium containing products is roughly estimated. For the reference case, the installed capacity of CIGS solar cells ranges from 12 to 387 GW in 2030 (31–1401 GW in 2050), depending on the energy scenario chosen. This translates to between 485 and 15,724 tonnes of primary indium needed from 2000 to 2030 (789–30,556 tonnes through 2050). One scenario exemplifies that optimistic assumptions for technological progress and handling in the anthroposphere can reduce cumulative primary indium demand by 43% until 2050 compared to the reference case, while with pessimistic assumptions the demand increases by about a factor of five. To meet the future indium demand, several options to increase supply are discussed: (1) expansion of zinc metal provision (indium is currently a by-product of zinc mining), (2) improving extraction efficiency, (3) new mining activities where indium is a by-product of other metals and (4) mining of historic residues. Potential future constraints and environmental impacts of these supply options are also briefly discussed.     

The Worldwide Availability of Fluorspar

This paper reviews a recent assessment of fluorspar reserves and resources for 13 market economy countries and the People's Republic of China, and how they relate to the overall availability of fluorspar on the world market. Current world production, consumption and world trade issues are discussed.
Nearly 5 million tonnes of fluorspar were produced in 1985, and approximately 60% of that enters the world export market. In recent years world trade has started to shift away from the acid, metallurgical and ceramic grades of fluorspar, as ore-producing countries look towards higher-value downstream products.
Total potentially recoverable fluorspar from 52 major producing mines and deposits is estimated at nearly 95 million tonnes (as of January 1985). The Republic of South Africa accounts for 31% of the reserves, with Mexico and the People's Republic of China each contributing 18%.
The average total cost and availability of fluorspar is evaluated. Approximately 75% of acid-grade fluorspar evaluated is potentially available at or below a 1985 constant-dollar cost of US$110 tonne⁻¹. Nearly 94% of metallurgical grades are potentially available at costs of US$75 tonne⁻¹ and below, and virtually all of the ceramic grades could be produced at costs below the 1985 reported market price of US$103 tonne⁻¹.     

Modeling Effects of Natural Flow Restoration on Metals Fate and Transport in a Mountain Stream Impacted by Mine Waste1

Abstract: The effects of natural flow restoration on metals fate and transport in the Upper Tenmile Creek Watershed, Montana, were modeled using the Water Quality Analysis Simulation Program developed by the U.S. Environmental Protection Agency (USEPA). This 50‐km² watershed has over 150 historic abandoned mines, including mine waste rock and tailings, as well as adits discharging acid mine drainage, and is the primary drinking water supply for the City of Helena. Water supply diversions almost completely dewater some stream reaches during summer low flows, but the city is considering a new drinking water source and restoration of natural flows in Tenmile Creek as part of acid mine drainage remediation and broader aquatic habitat restoration. One dimensional steady‐state simulation of total recoverable cadmium, copper, lead, and zinc in the mainstem was performed, and the model was calibrated to June 2000 base‐flow data. Representative low‐flows in August and high‐flow snowmelt conditions in June were modeled using mean monthly natural flow estimates from the U.S. Geological Survey and representative USEPA metals concentrations data. The modeling showed that total recoverable metals concentrations, and especially loads, can vary significantly among input locations and over time in the watershed. Some data gaps limit evaluation of variability and increase uncertainty in several locations. Model results indicated, however, that natural low‐ and high‐flow restoration by itself can reduce some metals concentrations in the mainstem compared to June 2000 values, which were influenced by significant water diversion. Some values (such as Zn) may still exceed standards during natural August low flow due to the remaining high concentrations and loads in the primary inputs to the mainstem. Others (such as Cu) can increase during high flow due to remaining mine waste sources and loading of particulate Cu associated with erosion and transport of solids. Greater than 50% reduction in concentrations and loads from some of the main tributaries may be necessary to meet all standards, especially for potential particulate loads with higher flows in June.     

Evaluation of leachates from coal refuse blended with fly ash at different rates

There is great interest in returning coal combustion products to mining sites for beneficial reuse as liming agents. A column study examined the effects of blending two coal fly ashes with an acid-forming coal refuse (4% pyritic S). Both fly ashes were net alkaline, but had relatively low neutralizing capacities. One ash with moderate alkalinity (CRF) was bulk blended with coal refuse at 0, 20, and 33% (w/w), while another lower alkalinity ash (WVF) was blended at 0, 5, 10, 20, and 33% (w/w). The columns were leached (unsaturated) weekly with 2.5 cm of simulated precipitation for >150 wk. Where high amounts of ash alkalinity (>20% w/w) were mixed with the coal refuse, pyrite oxidation was controlled and leachate pH was >7.0 with low metal levels throughout the study. At lower rates of alkalinity loading, trace metals were sequentially released from the WVF ash as the 5, 10, and 20% treatments acidified due to pyrite oxidation. Lechate metals increased in proportion to the total amounts applied in the ash. In this strongly acidic environment, metals such as Mn, Fe, and Cu were dissolved and leached from the ash matrix in large quantities. If ash is to be beneficially reused in the reclamation of acid-producing coal refuse, the alkalinity and potential acidity of the materials must be balanced through the appropriate addition of lime or other alkaline materials to the blend. Highly potentially acidic refuse material, such as that used here, may not be suitable for ash/refuse codisposal scenarios.     

聚合硅酸硫酸铝对印染废水的预处理实验研究

本文采用硅酸钠、硫酸和硫酸铝为原料，制备出无机高分子絮凝剂聚合硅酸硫酸铝，探讨了聚合硅酸硫酸铝对广东某毛纺企业印染废水的应用性能。结果表明，聚合硅酸硫酸铝对COD和色度的去除率优于硫酸亚铁，COD和色度去除率分别可达31．8％和84％，减轻了后续生化系统的压力。     

The Worldwide Availability of Phosphate Rock

The US Bureau of Mines has investigated the resource potential of 201 phosphate mines and depositee in 28 market economy countries and 17 mines and deposits in the USSR and China. The 201 mines and deposits contain an estimated 34.2 billiong tonnes (t) of recoverable phosphate rock (at the demonstrated resource level), with Morocco and Western Sahara accounting for 61% (21 billion t) and with the USA accounting for 19% (6.4 billion t). The 17 mines and deposits evaluated in the USSR and China contain approximately 1.5 billion t of potentially recoverable phosphate rock. Potential annual capacity from low-cost, high-grade producing mines in the USA is estimated to decline significantly during the latter half of the next decade, and the US phosphate fertilizer industry will have to obtain phosphate rock by developing new, higher-cost, lower-grade mines or import phosphate rock to satisfy anticipated demand in the next century. Of the world's new production capacity that are likely to be developed over the next decade, slightly over one-third could be produced at an estimated 1981 cost of $40/t or less, and about two-thirds would cost in the $40 to $50 per tonne range (including a 15% rate of return). In comparison, most of the competing phosphate rock from producing mines in Morocco could be produced for less than $40/t.     

Improving the accuracy of sediment-associated constituent concentrations in whole storm water samples by wet-sieving

Sand-sized particles (>63 microm) in whole storm water samples collected from urban runoff have the potential to produce data with substantial bias and/or poor precision both during sample splitting and laboratory analysis. New techniques were evaluated in an effort to overcome some of the limitations associated with sample splitting and analyzing whole storm water samples containing sand-sized particles. Wet-sieving separates sand-sized particles from a whole storm water sample. Once separated, both the sieved solids and the remaining aqueous (water suspension of particles less than 63 microm) samples were analyzed for total recoverable metals using a modification of USEPA Method 200.7. The modified version digests the entire sample, rather than an aliquot, of the sample. Using a total recoverable acid digestion on the entire contents of the sieved solid and aqueous samples improved the accuracy of the derived sediment-associated constituent concentrations. Concentration values of sieved solid and aqueous samples can later be summed to determine an event mean concentration.     

Substance flow analysis of cadmium in Korea

Substance flow analysis (SFA) of cadmium in Korea was carried out to analyze and predict cadmium flows, stocks, and future flows using both static and dynamic models. Cadmium is widely used in industry due to its strong corrosion and chemical resistance at high temperature, excellent electrical conduction, and low melting-point. Cadmium is produced as a by-product from the production processes for zinc and lead ingots. It is used for Ni–Cd batteries, polyvinylchloride (PVC) stabilizers, alloy products, pigments, and others.This examines the current cadmium flows and stocks using static SFA, and aims in predicting the future cadmium flows and stocks in Korea using dynamic SFA. From the static model, 2820 tonnes of cadmium ingots were produced, 0.04 tonnes imported and 2740 tons exported in Korea in 2009. In addition, 81 tonnes of cadmium were used in the manufacture of cadmium products: 80 tonnes for cadmium alloy products and 1 tonne for others. Finally, 175 tonnes of cadmium were imported into Korea for Ni–Cd batteries, 140 tonnes for PVC stabilizers, and 55 tonnes for pigments. Cadmium was used in various industries such as construction (221 tonnes), electrics and electronics (130 tonnes – including cadmium in imported products), transportation (30 tonnes) and others (30 tonnes). In 2009, 430 tonnes of industrial cadmium were discharged, with 10 tonnes being recycled and 420 tonnes discarded.From the dynamic model, cadmium stocks in Korea were estimated to be about 5120 tonnes in 2009. The industrial consumption in 2030 will be reduced to only 110 tonnes, only 27% of the current consumption of 410 tonnes in 2009, due to DIRECTIVE 2002/95/EC OF THE EUROPEAN PARLIAMENT of 27 January 2003 on the restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS). One possible solution to the Cd oversupply problem is use in cadmium telluride photovoltaic (CdTe PV) systems which have low life cycle Cd emissions (0.02 g Cd/GWh) and high end-of-life semiconductor recycling yields (95%).     

Bioproduction of ferric sulfate used during heavy metals removal from sewage sludge

Toxic metals removal from wastewater sewage sludge can be achieved through microbial processes involving Acidithiobacillus ferrooxidans. The oxidation of ferrous ions by A. ferrooxidans, cultured in sewage sludge filtrate, was studied in both batch and continuous flow stirred tank reactors. Sewage sludge filtrate containing natural nutrients (phosphorus and nitrogen) was recovered as effluent following the dehydration of a primary and secondary sludge mixture. Batch and continuous flow stirred tank reactor tests demonstrated that A. ferrooxidans were able to grow and completely oxidize ferrous iron in a culture medium containing more than 80% (v v(-1)) sewage sludge filtrate with 10 g Fe(II) L(-1) added. Toxic levels were reached when total organic carbon in the sewage sludge filtrate exceeded 250 mg L(-1). The ferric iron solution produced in the sludge filtrate by A. ferrooxidans was used to solubilize heavy metals in primary and secondary sludge. The solubilization of Cu, Cr, and Zn yielded 71, 49, and 80%, respectively. This is comparable with the yield percentages obtained using a FeCl(3) solution. The cost of treating wastewater sewage sludge by bioproducing a ferric ion solution from sewage sludge is three times less expensive than the conventional method requiring a commercial ferric chloride solution.     

What caused the slack demand for metals after 1974?

This paper explores the general reasons for the sudden decline in the growth of world metal demand which began after 1974 and continues to impact the metal industries. For all of the eight metals studied, except aluminium, the dominant cause of this atrophy in demand is the stagnation in total world economic growth, which has caused reduced demand for all goods and services. In addition, consumer preferences have shifted away from metal-intensive goods, further reducing the need for metals. However, materials substitutions and manufacturing technologies have continued to evolve towards lower use of metal in each product at much the same rate after 1974 as before. Therefore, these aspects do not explain the sudden shortfall after 1974 except in the case of aluminium which experienced a dramatic change during the energy crisis years.     

Value from shredder waste: Ongoing limitations in the UK

Shredder residue is the residue from the shredding of end-of-life vehicles and white goods, after removal of the main metals. Approximately 850,000 tonnes of shredder waste is produced in the UK each year, and historically sent to landfill. Due to European legislation such as the End-of-Life Vehicle (ELV) Directive and the Landfill Directive there is pressure to minimise this waste through recycling and recovery.In this paper, primary data are presented showing that 40% of materials are potentially recoverable in the coarser fraction of UK automotive shredder residue (>30 mm). Barriers to such recycling are discussed in the context of several recent drivers, including this waste's possible reclassification as hazardous.The lack of full and timely implementation of the ELV Directive in the UK has made it an ineffective driver, and it is now unlikely that its 2006 recycling targets will be met as intended.     

有色金属行业CO2排放估算方法研究

通过对国内外有色金属行业温室气体排放估算方法研究现状的分析，将联合国政府间气候变化专门委员会（IPCC）温室气体排放清单指南、国际有色行业协会和环境科学研究中的一些常用算法，总结归纳应用于有色金属行业温室气体的排放量估算，从估算方法和结果上分析各种方法的优缺点和使用条件。以原铝生产CO2排放估算为例，对有色金属温室气体排放进行实证分析，为有色金属行业温室气体排放估算提供参选方法，促进有色金属工业的节能减排。