The recycling of rare earths from waste tricolor phosphors in fluorescent lamps: A review of processes and technologies

Rare earths have become the most important strategic resources, widely used as functional materials in industry and many other aspects of life due to its optical, electrical, and magnetic characteristics. As a consequence, a considerable number of wastes containing rare earths such as abandoned fluorescent lamps are generated and lost. Considering the scarcity in availability and supply of certain raw materials, waste tricolor phosphors are viewed as potential resources that can be mined in urban areas for their reutilization as rare earths. A number of studies in this area have been carried out all over the world.The purpose of this paper is to review the current status of recycling technologies of rare earths from waste tricolor phosphors in fluorescent lamps. The main characteristics of the tricolor phosphors were introduced, and also a detail review of the typical single recycling and reusing technologies with regard to waste tricolor phosphors was carried out in present paper. After that, several combined recycling processes and technologies were evaluated. Based on the review, the prospects of recycling technologies were suggested.     

Social responsibility and resource extraction: Are Chinese oil companies different?

In order to meet China’s rapidly increasing demand for oil, Chinese oil companies have been investing in oil production around the world. This article addresses one specific aspect of the more generalized fears expressed about China’s increasing demand for natural resources which is the impact that its oil companies will have on the corporate social responsibility (CSR) movement. In doing so, it limits its analysis to the three main Chinese oil companies: the China National Petroleum Corporation (CNPC), the China Petroleum and Chemical Corporation (Sinopec) and the China National Offshore Oil Corporation (CNOOC) and their investments in sub-Saharan Africa.     

Accumulation of rare earth elements in corn after agricultural application

Using both pot and plot experiments, the dose-dependent accumulation of rare earth elements (REs) in corn (Zea mays L.) after application of an agricultural REs mixture was measured. In the pot experiment, the dose-dependent accumulation of REs in corn root and stem was observed, but it could not be detected in corn leaf under the dosage of 20 mg REs kg(-1) soil (oven-dry mass). The non-observed effect concentration (NOEC) for accumulation of REs in corn seedling with the pot experiment was 1.0 mg REs kg(-1). In the plot experiment, the dose-dependent accumulation was observed at an early stage after application of REs and the NOEC value of 32 mg REs m(-2) was obtained. At harvest, no dose-dependent accumulation of REs was observed in any part of the corn. These results can be confirmed by the fingerprinting analysis based on the differences between La to RE ratios in the REs mixture and in pot or plot soil. We observed that the plant shows no preference on individual RE and the results of fingerprinting indicated clearly the incorporation of exogenous REs in plant tissues, in a similar manner as that observed in the dose-dependent distribution of RE concentrations. The results indicated also a translocation process of REs from plant root to leaf when applied to soil or from leaf to root when applied to leaf. A homeostatic regulation mechanism for excessive uptake of REs in plants is suggested to regulate the concentrations of REs in the plant.     

The National Heritage Resource Act (1999): Can legislation protect South Africa's rare geoheritage resources?

In South Africa, rare geological specimens are protected by the National Heritage Resource Act (1999). These portable geoheritage objects are neither defined nor described in this Act making their geoheritage status questionable. Thirteen categories and criteria for establishing a geological specimen's rarity status are discussed and include (1) rarity as defined by abundance per se; (2) rarity of a particular habit (external shape or form) of a mineral; (3) rare pseudomorphs; (4) rarity of a particular variety of a mineral; (5) rarity of a particular colour of a common mineral; (6) rarity defined by size; (7) rarity defined by quality; (8) a common species, but rare for a particular locality; (9) rarity of associations of minerals; (10) rarity determined by source being depleted, exhausted or mined out; (11) rare inclusions in minerals; (12) previously rare, now common specimens and (13) miscellaneous criteria that produce rare specimens. Geological specimens (resources) are complex objects when defining their rarity status and multiple rarity factors can apply to single specimens. A lack of clear criteria for defining rare geological specimens appears to place the National Heritage Resource Act (1999) in direct conflict with the more recent Mineral and Petroleum Resources Development Act (2002) which legitimizes the legal exploitation of any mineral resource.     

An analysis of future platinum resources,emissions and waste streams using a system dynamic model of its intentional and non-intentional flows and stocks

Platinum is increasingly used intentionally and non-intentionally in several applications. This has raised the concern about its future resources, emissions and losses during its life cycle. On the one hand, increasing platinum emissions might affect human health. On the other hand, the accumulated platinum in mineral waste, soil, landfill sites and construction materials as a result of the emissions, losses and the utilization of secondary materials can be seen as potential resources for platinum. This paper is aimed at (1) analyzing the long term impacts of the use of platinum intentionally and non-intentionally on its future demand and supply, release to the environment and accumulation in mineral waste, soil, landfill sites and construction materials and (2) quantifying the amount of platinum in secondary materials that would be available for platinum future supply. The analysis is carried out on a global level using a system dynamic model of platinum intentional and non-intentional flows and stocks. The analysis is based on four scenarios for the introduction of fuel cell vehicles (FCVs). The results show that platinum demand is increasing overtime in all scenarios at different rates and its identified resources are expected to deplete before the end of the century with or without the introduction of FCVs. The release of platinum to the environment and the accumulation in soil are expected to decrease when conventional ICE vehicles is replaced by FCVs. The amount of platinum accumulated in mineral waste, soil, landfill sites and construction materials by the time platinum is depleted are more than double its identified resources and would be potential resources for platinum that are available in different parts of the world. The methodology presented in this paper can be used in the assessment of other technologies and other metals.     

Natural resources and development: The gold sector in Mali

Resource-rich countries do not necessarily perform well, especially developing countries. A debate has developed since the 1990s about a “resource curse” hypothesis, which threaten to impede the resource-rich countries in taking advantage of their natural endowments. In Mali, a less-developed country, gold export has substantially increased since the 1990s. In this paper we show that widespread analyses, such as those of the Dutch disease and the quality of institutions, are not sufficient to understand what is at stake in Mali, and that the mining sector has proved to be neither a blessing nor a curse, at least until the present. Gold mining has brought budget revenues but induced few spillovers. As gold mining has now come to maturity, the die is probably cast.     

Economic and social effects analysis of mineral development in China and policy implications

Mineral development has contributed greatly to China's economic and social development. Many challenges remain, however, including environmental pollution and resource waste in practice, as well as a dearth of systematic theoretical research. The goal of this study is to analyze the economic and social effects of various mineral developments in China from diversified perspectives, so as to provide the basis for the formulation of China's mineral development policy. The input–output effects, industrial linkage effects and income distribution effects of different mining industries are quantitatively analyzed by adopting basic hypotheses of input–output economics, industrial linkage model and income distribution antitheses based on the latest available official data from China Statistical Yearbook from 2004 to 2010 and the 2007 Input–Output Table of China. The empirical results obtained in this study indicate that all mineral development industries, especially coal mining and washing, and petroleum and natural gas extraction industries, have given a strong impetus to the increase of China's fixed asset investment and GDP. Moreover, they have provided a large number of jobs, thereby alleviating ongoing employment pressure, and they have also played a positive role in promoting China's technology investment. The analysis of industrial linkages demonstrates that mining industries are basic to the national economy and produce a significant impetus to its downstream industries, but create weak pull effects in terms of national economic development. From the perspective of income distribution, mining industries play an important role in increasing China's fiscal revenue and per capital income. Hence, China's mineral development policy should (1) encourage additional investment in technology for exploration and development to insure sufficient supply and expand the input effects; (2) attract additional talent to work in remote regions; (3) optimize the industrial structure and promote the industrial transformation in resource regions; (4) adjust the interest distribution between the central and local governments to enable the local regions to become more self-sufficient; and (5) enhance the legal environment so that companies can more readily undertake their social responsibilities voluntarily.     

Rare-Earth Oxide Availability in Market Economy Countries

This paper presents a review by the Bureau of Mines on the 1985 status of the rare earths industry in the Market Economy Countries (MEC). Demonstrated resources for the 38 evaluated MEC properties are estimated at 3.3 million metric tons of recoverable rare-earth oxides. About 75% of the total is contained in producing properties, and 21% are contained in undeveloped properties; the remaining 4% are contained in past producers. Total MEC production in 1985 was estimated at 30 500 mt. Assuming demand does not increase sharply, producing properties can continue to meet overall rare earths demand through at least the end of this century.     

The forgotten resource curse: South Africa's poor experience with mineral extraction

Studies of the resource curse as it affects African states abound, yet few deal specifically with the experiences of South Africa. The inability of countries to convert natural resource wealth into income and improved development measures remains highly pertinent and is especially apparent in Africa's largest economy. This paper takes a unique approach to study the resource curse by comparing South Africa's political economy with the existing resource curse literature. Using data from international organisations, studies of poverty and qualitative evidence this paper examines South Africa's experience with mineral extraction. It is found that South Africa has experienced many of the symptoms outlined in the resource curse literature including relatively slow GDP growth, gross inequalities, entrenched poverty and the creation of a rentier state. Overall, it is concluded that South Africa has failed to benefit from natural resource wealth and can be classified as a resource cursed state. Not only has mineral wealth failed to benefit much of South Africa's population, sections of society have actually been harmed through the process of mineral extraction. This paper is the first to examine South Africa in light of the current resource curse literature and to conclude that the state far more closely resembles its sub-Saharan African neighbours than its upper-middle income peers.     

A review of the PGM industry,deposit models and exploration practices: Implications for Australia's PGM potential

Australia is prospective for platinum group metal (PGM) mineralisation (in particular primary magmatic reef, primary magmatic by-product, late magmatic and hydrothermal, and alluvial placer type) but its known PGM endowment is negligible compared to that of South Africa, Russia, the USA and Canada. Most Australian PGM projects are operated by mid-cap or junior companies and form part of larger, more diverse project portfolios held by these explorers. Most projects were ‘hot’ while market conditions were favourable. However, as other metals became ‘fashionable’ and market conditions for PGM changed, so did the focus of these companies. Pure PGM companies are rare in Australia. The search for and development of PGM-only deposits in Australia are high risk business activities. No new primary PGM deposits have been discovered since the mid to late 1980s and none of the significant deposits that were discovered or evaluated in the 1980s have been mined. This review suggests that at least several A$10 million but more likely several A$100 million were sunk into PGM exploration and development projects but none advanced to the mining stage. The viability of Australian PGM projects is very sensitive to (1) metal prices, (2) the US$/A$ exchange rate, and (3) large capital expenditure requirements relative to the small size of Australian PGM-only deposits. Most PGM-only projects were initiated at times of high PGM prices. However, advanced exploration, feasibility studies and project development always lagged behind the price booms. South Africa, Russia and Canada contain approximately 98% of the known global PGM reserves. This situation has a very negative effect on the Australian PGM industry as the well-endowed nations continue to receive the lion's share of exploration spend and new projects.     

New mercantilism: A perspective on how politics is shaping world metal supply

The major countries consuming metals tended historically to be also the major countries producing them. It was in their interest to promote mine development to provide low cost raw materials. Over the past fifty years, the share of global production accounted for by consuming countries has declined and producers and consumers of metals have been slowly moving into separate camps having distinct and differing interests. As a consequence of this, governments of producing countries have become more focused on how to maximise the benefit of metal extraction to their economies rather than on how to supply cheap raw materials; a tendency which has found expression in resource nationalism. Governments of consuming countries have in response become increasingly concerned about the implications of this tendency to their economic development and some countries, most notably China, have adopted robust policies to secure their supplies. Through their actions to influence capital flows within the mining industry and to force metals trade into channels which better serve their national interests (a process characterised here as ‘new mercantilism’), metal producing and metal consuming countries are reshaping global supply.     

Impact of different public E&P policies on natural gas reserves and production in Pakistan

Low wellhead domestic gas prices over the past few years have led to the beginning of a shortage in natural gas reserves and production in Pakistan. Gas demand steadily rises in all sectors for being an economical fuel as compare to substitutes. In the view of foregoing consumption trend, the demand for gas is expected to grow with a higher pace during the 2010s. On the contrary, indigenous gas reserves are running out and cannot keep up with the demand. This paper examines the extent of upstream activities in different petroleum policy regimes. The wellhead price for indigenous gas is compared with the prices of alternatives (for example, gas import prices). In order to put the problem in perspective, the relationship between wellhead gas price and cumulative gas reserves in Pakistan are analyzed and we find that the looming gas shortage can be ameliorated in the short-run and eliminated in the long-run through incentivized wellhead price. To put it briefly, the idea is mooted to first take advantage of huge domestic reserves to ensure competitive consumer prices for gas. The findings are applicable to several other economies with under-developed natural resources.     

How have reforms fuelled the expansion of artisanal mining? Evidence from sub-Saharan Africa

This paper investigates whether and how World Bank mining sector reforms have fuelled the expansion of illegal artisanal mining activity in Sub-Saharan Africa. In doing so, the analysis examines three issues. First, the emerging correlation between reforms and poverty, mainly a result of increased unemployment caused by Structural Adjustment Programmes and concurrent privatisation of state-owned enterprises, is explored. Second, the possibility that reform of large-scale mining has decreased available land for peasant farming as well as legalised small-scale mining activity is discussed. Finally, the notion that the regularisation of informal mining activities has been an exceedingly bureaucratic procedure in Africa, therefore providing individuals with little incentive to operate within the legal domain, is examined. Faced with few employment prospects, a growing number of Africans are pursuing employment in the artisanal mining sector, a worrying prospect given its intimate association with environmental degradation and HIV/AIDS.     

Drainage and utilization of Chinese coal mine methane with a coal–methane co-exploitation model: Analysis and projections

Coal mine methane (CMM) released during coal mining attributes to unsafe working conditions and environmental impact. China, the largest coal producer in the world, is facing problems associated with CMM such as fatal gas accidents and intense greenhouse gas emission along the path to deep mining. Complicated geological conditions featured with low permeability, high gas pressure and gas content of Chinese coal seams have been hindering the coal extraction. To solve these problems, a model of coal–methane co-exploitation is proposed. This model realizes the extraction of two resources with safety ensured and has been successfully applied in Huainan coalfield, China. The current situation of drainage and utilization of CMM in China are diagnosed. Connections between the coal production, methane emissions, drainage and utilization are analyzed. Estimations of future coal production, methane emissions, drainage and utilization are made in a co-exploitation based scenario. The emitted, drained and utilized CMM are projected to reach 26.6, 13.3 and 9.3 billion m³, respectively by adapting the assumption of 3800 million metric tons of coal production by 2020.     

How can public–private partnerships contribute to security and human rights policy and practice in the extractive industries? A case study of The Democratic Republic of Congo (DRC)

Across sub-Saharan Africa, the presence of foreign large-scale mining companies is increasing. This is in part a result of depleting resources in countries such as Canada, United States and Australia, and in part from a more favorable national mine investment climate in several mineral-rich African countries. Their increased presence raises important questions around the potential role and function of Corporate Social Responsibility (CSR) in the sector. In post-conflict and/or fragile states, CSR has further implications for conflict and risk mitigation strategies to ensure the protection of human rights. One CSR approach increasingly being considered is the public–private partnership, whereby companies, public donors, and development agencies leverage their relationships for mutual benefit. There is merit in exploring its function in post-conflict fragile states, where socio-economic needs are high and the capacity of the state to respond to a variety of mine governance challenges is limited. Two case studies from the Democratic Republic of Congo (DRC) are presented, and their policy implications, discussed.     

From landfill to water,land and life: The creation of the Centre for stone materials aimed at secondary processing

This paper focuses on the creation of a Centre for the recycling of stone materials. The Centre will be able to offer a range of activities amongst which is the improvement of the production chain of the Orosei Marble district in Sardinia, Italy. Several companies operate within the marble producing area, specializing in both quarrying and stone processing. They have formed a Consortium in order to rehabilitate an area of more than 17 ha. The restoration will be carried out through an environmentally sustainable procedure. The area was previously used as a landfill for waste deriving from marble quarrying and processing. At that time unshaped blocks of various sizes (which are unsuitable to block-cutter sawing), waste deriving from both block sawing and slab/strip cutting (such as broken slabs, strips, tiles) and microfine dust from filter presses of water treatment plants were representing an environmental problem. The local administration was struggling to find new areas which could be used for landfills, resulting in an additional cost for the landfill, ultimately affecting the variable production costs. The project involves the building of a venue to be used for temporary storage, treatment of wastes produced by both quarrying and primary processing, in order to make them suitable as secondary raw materials. The project also deals with the catch basin hydrology of the area involved in the project, the building of a multifunctional centre, the landscaping and other environmental features such as vehicle traffic and slopes greening.     

Ecological effects of coastal marsh impoundments: A review

Many coastal resource managers believe estuarine marshes are critically important to estuarine fish and shellfish, not only because of the habitat present for juvenile stages, but also because of the export of detritus and plant nutrients that are consumed in the estuary. Concern has been widely expressed that diking and flooding marshes (impounding) for mosquito control and waterfowl management interferes with these values of marshes. Major changes caused by impoundment include an increase in water level, a decrease in salinity, and a decrease in the exchange of marsh water with estuarine water. Alteration of species composition is dramatic after impoundment. Changes in overall production and transport phenomena, however—and the consequences of these changes— may not be as great in some cases as the concern about these has implied. Although few data are available, a more important concern may be the reduction of access by estuarine fish and shellfish to the abundant foods and cover available in many natural, as well as impounded, marshes. Perhaps even more important is the occasional removal of free access to open water when conditions become unfavorable in impounded marsh that is periodically opened and closed. Collection of comparative data on the estuarine animal use of various configurations of natural and impounded marshes by estuarine animals should lead to improved management of both impounded and unimpounded marshes.     

Evaluation of recycling efforts of aircraft companies in Wichita

The number of manufactured aircraft has been continuously increasing worldwide because of the high demand for airline transportation. During manufacturing, many advanced materials and devices are used to build various sizes and shapes of aircraft. However, most of these materials and devices require considerable energy and labor to produce, so reusing these at any life stage of the aircraft offers many economic and environmental benefits, and is considered lucrative and environmentally responsible. Several recyclable materials—composites, metals and alloys, wires, wood, paper, plastics, electronics, and avionics—emerge as waste streams during the manufacturing of aircraft. Many aircraft companies have been recycling these materials to remanufacture aircraft parts or other products for more sustainable production. In the present study, we evaluated the recycling efforts of local aircraft companies in Wichita, KS. These efforts were considered in terms of recycling efficiency/rate and environmental benefits. These included cradle-to-gate (CTG) life-cycle inventory analysis of the materials, carbon dioxide emissions, virgin material replacement with recycled materials, and natural resources usage. Our findings show that there exists a significant potential for contributions to sustainability as well as environmental and health benefits in the region from recycling by aircraft manufacturing plants.     

European aggregates production: Drivers,correlations and trends

Aggregates constitute the biggest branch of mining by production volume and the second in value, after the sector of fossil fuels. Their close connection with the construction industry places them among the most used materials worldwide, second only to water. Despite its significance, the sector suffers from the non-systematic register of production data, resulting in weakness to study the main features affecting the sector’s structure and future capacity. The paper focuses on the aggregates production in 26 European countries. Data from available sources are gathered and combined for a 10-year period (1997–2006), as an effort to provide a clear view of the major attributes of this vital industrial sector. Through a thorough analysis, the main drivers in aggregates production are revealed and existing correlations and trends are identified. New findings are also presented, for example the significance of GDP from construction and the strong connection of aggregates production per capita with the residential building sector.     

Life cycle assessment of biofibres replacing glass fibres as reinforcement in plastics

This article aims to determine the environmental performance of China reed fibre used as a substitute for glass fibre as reinforcement in plastics and to identify key environmental parameters. A life cycle assessment (LCA) is performed on these two materials for an application to plastic transport pallets. Transport pallets reinforced with China reed fibre prove to be ecologically advantageous if they have a minimal lifetime of 3 years compared with the 5-year lifetime of the conventional pallet. The energy consumption and other environmental impacts are strongly reduced by the use of raw renewable fibres, due to three important factors: (a) the substitution of glass fibre production by the natural fibre production; (b) the indirect reduction in the use of polypropylene linked to the higher proportion of China reed fibre used and (c) the reduced pallet weight, which reduces fuel consumption during transport. Considering the whole life cycle, the polypropylene production process and the transport cause the strongest environmental impacts during the use phase of the life cycle. Since thermoplastic composites are hardly biodegradable, incineration has to be preferred to discharge on landfills at the end of its useful life cycle. The potential advantages of the renewable fibres will be effective only if a purer fibre extraction is obtained to ensure an optimal material stiffness, a topic for further research. China reed biofibres are finally compared with other usages of biomass, biomaterials, in general, can enable a three to ten times more efficient valorisation of biomass than mere heat production or biofuels for transport.