Sorption of selenate on soils and pure phases: kinetic parameters and stabilisation

This study was conducted to identify the principle selenate carrier phases for two selected soils, by comparing their reactivity with selenate to that of pure phases of the solids. Silica, calcium carbonate, aluminium hydroxide, goethite, bentonite and humic acid were selected as the main soil carrier phases. Comparisons were made first on the parameter values obtained with the best fit of a kinetic sorption model which can discriminate instantaneous sorption from kinetically limited sorption. Then comparisons were made of the ability for each solid to stabilise selenate by measuring the ratio of the partition coefficient for sorption (Kd_sorption) over that of the desorption (Kd_desorption). Kinetics and stabilisation were used to help elucidate the nature of interactions with the test solid phases for a large range of selenate concentrations. The experiments were conducted over 165 h in batch reactors, the solid being isolated from the solution by dialysis tubing, at two pH (5.4 and 8) and three selenate concentrations (1 × 10⁻³, 1 × 10⁻⁶ and 1 × 10⁻⁸ mol L⁻¹). The results obtained showed that only aluminium hydroxide can sorb selenate throughout the studied pH range (pH 5.4 to 8.0). The sorption capacity on this mineral was high (Kd_sorption > 100 to 1 × 10⁴ L kg⁻¹) and the selenate was mainly stabilized by the formation of inner sphere complexes. The sorption on goethite occurred at pH 5.4 (Kd_sorption 52 L kg⁻¹), mainly as outer sphere complexes, and was null at pH 8. On silica, a weak sorption was observed only at pH 5.4 and at 165 h (Kd_sorption 4 L kg⁻¹). On bentonite, calcium carbonate and humic acid no significant sorption was observed. Concerning the two soils studied, different behaviours were observed for selenate. For soil Ro (pH 5.4), Kd_sorption was low (8 L kg⁻¹) compared to soil Bu (pH 8) (70 L kg⁻¹). The sorption behaviour of selenate on soil Ro was mainly due to outer sphere complexes, as for goethite, whereas for soil Bu the sorption was mainly attributed to inner sphere complexes followed by reduction mechanisms, probably initiated by microorganisms, in which no steady state was reached at the end of the 165 h experiments. The sorption of selenate decreased when concentrations reached 1 × 10⁻³ mol L⁻¹, due to solid saturation, except for aluminium hydroxide. Reduction of selenate seemed also to occur on goethite and soil Ro, for the same concentration, but without preventing a decrease in sorption. Thus, this work shows that the comparison of selenate behaviour between soil and pure phases helps to elucidate the main carrier phases and sorption mechanisms in soil.     

Imperatives for attracting investment and technology in the Indian mining sector

In India, the mineral resource inventory and the production of a large number of important minerals have registered significant increases during the last few decades. Yet the country continues to be a net importer of many high value and scarce minerals and metals, like gold, diamond, and several base metals. Exploration and development of the resources of these minerals are technology- and capital-intensive. To bring technology and capital through foreign direct investment (FDI) into the Indian mineral sector, it is imperative to lay stress on: accurate resource estimation and categorization, as well as realistic projection of the true values; rationalization of legislative measures based on R&D studies and reorganization of the implementation machinery; conducive tax structure; notification of acts and rules applicable to offshore mineral resources; time-frames for granting licences and leases; encouragement to labor productivity by rationalizing labor laws; reforms in the monetary system to increase market competitiveness of Indian minerals; and judicial reforms. FDI in the Indian mineral sector is important to firm up the knowledge-base of mineral resources and their optimum exploitation.     

Mineral consumption in the UK, 1945–1980: A statistical analysis

Trends in the UK consumption of 12 metallic and 19 non-metallic minerals are examined for the period 1945–1980. Comparisons are drawn between these trends and developments in per capita GDP, total world consumption and UK mineral processing capacity. Although the consumption of most minerals has shown a tendency to stagnate or decline in recent years, taking the post-war period as a whole the consumption of non-metallics has displayed a faster and more sustained growth than that of metallics; thus their share of the total value of minerals consumed in the UK has increased significantly.     

Industry Response to the Challenge of Sustainability: The Case of the Canadian Nonferrous Mining Sector

/ The paper investigates how the Canadian nonferrous sector is tackling the challenge of sustainable development. Although there is no consensus as to what sustainable development means in practice for management in the sector, at least three dimensions must be taken into account: (1) metals are recyclable, the availability of this resource is not a concern for the foreseeable future; (2) the need to minimize environmental impacts of metals exploration, extraction, transformation, consumption, and recycling; and (3) production activities should not be socially or culturally disruptive. The nonferrous mining industry faces several environmental problems. Some of the most significant are acid mine drainage, sulfur emissions, recycling, and metals toxicity. The industry has developed a number of responses to address these specific concerns as well as other more general challenges. Six strategies are described and analyzed: (1) research and development, (2) an effort of consensus building among stakeholders known as the Whitehorse Mining Initiative, (3) international networking, (4) active involvement in the development of environmental management standards, (5) management reorganization and (6) voluntary agreements. The importance of external factors in the shaping of corporate environmental management practices is discussed, in particular the role of government. Progress has been achieved in three areas: (1) managerial practices and organization, (2) reducing the impacts of ongoing operations and (3) minimizing future liabilities, but two significant fields of conflict remain, namely mining in wilderness areas and projects on aboriginal lands.KEY WORDS: Canada; Environmental management; Minerals industry; Nonferrous metals; Sustainable development; Whitehorse Mining Initiative     

用生态文明打造美丽新徐矿

以十八大提出的建设生态文明、美丽中国为指导,提出了美丽徐矿的概念、定义及目标,总结了近年来徐矿生态文明建设初步实践中取得的成效,明确了了建设美丽徐矿必须坚持的八项基本原则,分析了徐矿生态文明建设新实践中存在的八个方面的主要困难和问题,指出了徐矿生态文明建设新实践中必须实施的十个方面的保障措施。     

National minerals policies and stakeholder participation for broad-based development in the southern African development community (SADC)

This paper explains how the well-accepted concept of improved stakeholder participation during mineral policy development leads to a national mineral policy that accommodates the diverging views and interests that allows wide acceptance of decisions, enhancing the success of implementation and, ultimately, national benefits. This process is based on lessons learnt during the South African experience and has been successfully applied in the development of the Namibian and Malawian national minerals policies. An effective policy in the SADC will engineer the delicate balance between poverty reduction and an internationally competitive minerals sector. This balance enhances the possibility of long-term economic growth and development in the SADC region. The overriding advantage of this strategy is that it generates ‘home-grown’ policy instruments and implementation of mineral law with which stakeholders can identify. This process presents a new challenge to traditional policy formulation strategies in emerging economies and the bottom-up approach, linked to wide political support, allows the potential realisation of national objectives.     

US resources policy: The 1982 report to congress

This paper analyses the extent to which the new Reagan mineral policy will encourage increased US production, substitution, recycling and conservation, domestic stock-piling and diversification of foreign supplies. Major inadequacies of the mineral policy are the transfer of responsibility for research and development from the government to the unprepared private sector, the lack of emphasis on short-term research and development in mineral processing technology, and the lack of coordination between minerals policy and national security and foreign policy. However, overall the policy is a positive step towards reducing the current US minerals supply vulnerability.     

Mining and sustainable development: considerations for minerals supply

Sustainable development involves meeting the needs of human societies while maintaining viable biological and physical Earth systems. The needs include minerals: metals, fuels, industrial and construction materials. There will continue to be considerable demand for virgin mineral resources, even if levels of recycling and efficiency of use are optimal, and rates of population growth and globalisation decrease significantly. This article aims to stimulate debate on strategic issues for minerals supply. While the world has considerable stocks of mineral resources overall, international considerations of the environmental and social aspects of sustainable development are beginning to result in limitations on where mining will be conducted and what types of deposits will be mined. Current and emerging trends favour large mines in parts of the world where mining can be conducted within acceptable limits of environmental and social impact. Finding new deposits that meet such criteria will be all the more challenging given a disturbing global decline in the rate of discovery of major economic resources over the last decade, and the decreasing land area available for exploration and mining.
To attract responsible exploration and mining, governments of mining nations will need to provide: regional-scale geo-scientific datasets as required to attract and guide future generations of exploration; resource access through multiple and sequential land use regimes, and frameworks for dealing with indigenous peoples' issues; and arrangements for consideration of mining proposals and regulation of mines that ensure responsible management of environmental and social issues.
The minerals industry will need to continue to pursue advances in technologies for exploration, mining, processing, waste management and rehabilitation, and in public reporting of environmental and social performance.     

Mineral development,financing and cooperation: New forms of international participation?

Although relations between direct investors and host countries must steadily evolve to meet continually changing circumstances, this should be within a broadly stable framework. The basic technical and economic characteristics of mining should dictate the nature of that framework. In contemplating their experiences during the past decade many international mining companies might ruefully agree with Benjamin Franklin that: ‘in this world nothing can be said to be certain except death and taxes’. The aim of this paper is to highlight some of the important factors that must be taken into account by governments, international agencies and private investors contemplating large-scale mining projects. These inevitably dictate the forms of international participation in mining ventures.     

Regional development benefits of mineral projects

This paper discusses the development impact of mining and mineral processing on the regions in which they are located. The discussion is organized so as to be of relevance for policy formulation in resource-rich developing countries which consider the exploitation of their mineral wealth. The hypothesis is that mining technology, interpreted in a broad sense, has undergone a profound change since 1900. In consequence, experiences of mineralbased regional development in the industrialized countries around the turn of the century are of little relevance to the Third World in the 1980s. Contemporary mineral ventures have very weak regional development repercussions in the absence of forceful policies specifically directed towards the regional development goal.