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By Junji Shibata

In a present process to treat the tungsten carbide tool waste, the wastes are roasted in air and then an alkali leaching is carried out in an autoclave. An environmentally friendly process is required to recover rare metals (Co and W) from the wastes. The effect of mechano-chemical (MC) treatment on leaching of rare metals was investigated in this study. The solvent extraction and crystallization-stripping methods were applied to separate and recover tungsten and cobalt in the leached solutions. The MC treatment for the rare metal leaching is effective to dissolve rare metals from the wastes due to the change in crystalline structure of WC and oxidation of WC with KMnO4. Cobalt ions are extracted with D2EHPA by a cation exchange reaction. Tungsten in the leachate can be extracted by TOA (tri-octyl amine) as an extractant, because tungsten species exist as a form of anionic species in acidic solution. The rare metals in organic phase are recovered as insoluble salts such as oxalates and ammonium salts in the crystallization-stripping process. Keywords:unheated oxidation, solvent extraction, crystallization-stripping, recycling

Sep 1, 2012

By R. Steven Izatt

Green chemistry principles will be discussed, and examples will be given of the use of Molecular Recognition Technology (MRT) to selectively separate specialty metals such as cobalt, nickel, bismuth, rhenium, molybdenum, indium and germanium from various primary and secondary feed streams. Recovery of these metals has numerous advantages including (i) conservation of valuable resources, (ii) prevention of environmental damage, and (iii) elimination of capital and operating expenses due to re-processing or disposal of metal-bearing streams.

By Xiangjun Zuo

This paper firstly reviewed the state of the art in the recycling of used Printed Wiring Boards (PWB), and then presented part of the authors study on the combustion of PWB powders with and without the addition of catalyst. During the combustion of PWB powders without catalyst addition, there were two obvious exothermic reactions, one at 300-380oC, the other at 450-500oC. With the addition of catalyst during PWB combustion, there were no obvious exothermic reactions, indicating that dehalogenation reactions are not exothermic: The results showed that NaHCO3 and CaCO3 were very efficient to control the emission of Br2 and C6H6, lowering 80% compared to the case without catalyst, Na2CO3 can slightly control the emission of Br2 gas but not for C6H6 gas mission, and NaOH has no any effect of the control of both gases.

Jan 1, 2009

By Ronald R. Rose

Currently six economic heavy mineral deposits are known on the Penholoway Terrace. These are (from south to north) the Green Cove Springs Mine (GCS), Boulogne Mine, Folkston Mine, Mission, Lulaton, and Ludowici. The GCS deposit is located to the west of Highway 17 between the towns of Green Cove Springs and Palatka in the state of Florida and has been mined since 1972. To the north, the erosion created by Black Creek restricts the northern extension of the orebodies and to the south a karst depression and erosion by the St. Johns River restrict southern extensions. The deposit is 20 miles long and up to 4.5 miles wide. Deposit thickness is from 5 feet up to 45 feet. The deposit is a series of regressive barrier island sequences deposited during the Pleistocene along the ancient Penholoway and Wicomico shorelines. The initial transgression of the ocean up to the location of the western Henry orebody was an extensive sea-level still stand as evidenced by the unit thickness and stacked transgressive regressive sequences. This period was followed by sporadic regressing seas and still stands, progressing eastward and stranding the sand bodies which make up the East Extended, TE, and East TE Ridge orebodies. The orebodies are underlain by predominantly non-mineralized fluvial sands and occasional back barrier lagoonal deposited clays. There is a predominance of wetlands on the southern extents of the zone as the surface elevations decrease due to a large karst depression.

Jan 1, 2005

By Guo Chen, Jin Chen, Jinhui Peng

In this study, the influences of the green evaluation variables on the characterization of microwave shaft furnaces were systematically investigated. These variables include: resource consumption, environment impact, production cost, processing time and quality of microwave shaft furnaces. A greenness evaluation index, evaluation system and evaluation model of microwave shaft furnaces were established. The analytic hierarchy process and fuzzy comprehensive evaluation were applied to the evaluation process. Resource consumption and environment impact had a statistically significant effect on the green evaluation of microwave shaft furnaces. The results indicated that green evaluation techniques can be applied effectively and efficiently to the process manufacturing of microwave shaft furnaces.

Jan 1, 2015

By David Huber, John Halkyard

Deep Reach Technology, Inc. recently completed a multi-year cooperative research project for the U S Army Research Laboratory for the purposes of investigating recovery of rare earth elements from the seabed. This research led to the discovery of a potentially economical deposit in the Exclusive Economic Zone of the Cook Islands. In order to further develop this resource, Ocean Minerals LLC (OML) was formed in 2016 to explore the development of a deep-sea mining project to recover rare earth elements and scandium from the upper 10m of sediment in promising areas of the Cook Islands Exclusive Economic Zone. OML and the Cook Islands Investment Corporation signed an Agreement in 2016 giving OML exclusive rights to explore a 12000 sq km area and option rights over an additional 48,000 sq km. This poster presents the current status and activities related to this project.

Jan 1, 2017

By Janice Zinck

?Past? Images of Mining ?Historic practices have been poor ?Mining still widely perceived as environmental ?spoiler? ?Public only hears the bad news stories. Lessons Learned from the Past ?Sustainability matters ?Recognition of social and environmental responsibilities ?Recognition of importance of public concerns and perceptions ?Community engagement

May 1, 2009

By Louise Laverdure

Outline ?Background ?Issues and considerations ?Why do we need to innovate ?Green Mining Initiative ?Footprint reduction ?Innovation in waste management ?Ecosystem risk management ?Mine closure and rehabilitation ?The Future

May 1, 2011

Using the philosophy that 'change cannot be introduced through memos-you have to get people emotionallyinvolved', SRK's Environmental Group in South Africa is helping clients communicate their environmental management objectives more effectively through the powerful medium of interactive industrial theatre. Existing and pending environmental legislation, international pressures, and growing awareness of the environment have led South African industry to the point where responsible care, for both the environment and the health and safety of those affected by the activities of an industry, is now a focus of management policies.

Jan 1, 1995

Green policies have gained momentum since the 1972 Stockholm, Environment Conference. The environmental movement has influenced political initiatives both in New Zealand and abroad. Governments and international institutions have addressed local, regional and global environmental issues with varying degrees of success. New Zealand so far has not supported the United Nations' call for sustainable development in a consistent manner. New institutions and new rules for resource management mean there are opportunities to look after the land in different and more ecologically sensitive ways than has happened in the past. The increasing influence of regional councils in resource management planning will have important implications for mining and mineral exploration. These trends are discussed and possible future events outlined. Green policies have gained momentum since the 1972 Stockholm Environment Conference. Environmental issues are now global and the twentieth year Environment Conference planned for 1992 is likely to see new commitments made by world leaders and their national governments. Green politics may be the popular trend of the moment but green principles of managing the earth's resources are here to stay. There are many businessmen, many technologists, and many politicians who have hoped that the environmental movement was a passing fad and would fade into oblivion. The evidence is otherwise. Far from passing into oblivion, the environmental movement is growing rapidly. Each year brings further scientific data that indicates mankind is on a self destructive course unless we learn how to better manage the earth's natural resources. This information has contributed to a growing population of environmentally aware people. In the last 20 years there have been messages of concern about a population increase out of control and the energy crisis which focused on dwindling oil stocks. The issues are all interrelated including the present global issues of climate change and thinning ozone layers. The attention being given the messages by the United Nations and member states requires similar attention by industry. The problems have been identified; the challenge is to determine what should be done about them. Every challenge brings new opportunities and the future need not be doom and destruction. Mining is seen by some of the environmental action groups as unnecessarily destructive of the environment, but I do not see mining ceasing in the next few decades. Rather, the rules will be clearer with some areas excluded from mining, the methods of extraction will improve, the technology of processing will become more sophisticated and restoration of mining sites will be not only normal practice worldwide, but the end result may leave no hazards, may enhance the landscape and may result in acceptance of the industry by the general public. For that to happen, commitment and cooperation is required between the industry, the government, and society. As an Officer of Parliament my role is to review the system of agencies and processes established by Government for allocating, using and preserving natural resources and to report whether the system is maintaining and improving the quality of the environment. I also have a responsibility to see that the environmental planning and management carried out by public authorities is effective. That Ineans I have a keen interest in how the mining industry is administered by New Zealand public authorities, including Ministers of the Crown and district and regional councils. Today I intend to review the approach to resource management being taken by international agencies and by the New Zealand Government, and to comment on how environmental impact assessment for mineral exploration, as well as mining, may be administered in the future.

Jan 1, 1990

By C. E. M. Meskers

Electronic and Electric Equipment contains a range of components made of a wide variation of metals, plastics and other substances. Up to 60 elements can be found in complex electronic equipment: base metals, precious metals and special metals in circuit boards and batteries. Because of its amount WEEE represents a considerable metal resource with a higher special and precious metal content than found in ores. The Umicore integrated smelter and refinery recovers and supplies back to the market 17 different metals from EEE. Pre-treated materials enter state of the art, material and energy efficient metallurgical processes for environmentally sound recovery of metals and treatment of off gasses and hazardous substances. The organics in the feed function as reducing agent and alternative energy source during smelting for precious metal recovery. Lithium-ion batteries are treated using a dedicated process. As a result the environmental footprint of metals produced from EEE is much smaller than primary production.

Jan 1, 2009

By Boxun Lu, Juan Wei, Kun Chen, Wanlin Wang, Lejun Zhou

"Slag system is an indispensable part during the continuous casting process, and playing various important roles like absorbing inclusions, modifying heat transfer rate, preventing oxidation of molten steel, etc. to ensure the smooth process and excellent slab quality. However most slags contains more than 8% fluorides which tend to introduce a series of environmental and health problems. This study involves the research of the removal of fluorine through the chemical composition optimization. Through the studies of CCT, DHTT, XRD and SEM, it has been successfully founded that the crystalline phase of Ca11Si4B2O22 discovered in this study shows very similar crystallization property as Cuspidine (Ca4Si2O7F2), which is the most important crystalline phase in the current fluorine bearing slags. Moreover, the optimized free/low fluorine slag shows the opportunity to replace conventional high-fluorine mold slag for casting medium carbon steels that is regarded as the bottleneck of green slag development for continuous casting.IntroductionMold flux has been widely used in continuous casting to control heat transfer, lubricate the strand, absorb inclusions, provide insulation and prevent oxidation of the molten steel[1-3]. It usually contains fluorides, like CaF2, NaF etc., which are used to control the viscosity and solidification temperature of mold fluxes [4-5]. However, the presence of fluoride leads to corrosion of equipment, serious environmental pollution (toxic volatiles and water pollution), and high processing cost of cooling water[6-7]. Therefore, the study of low or free fluorine mold flux is of interest and attracts worldwide attention.S. Y. Choi et al. [4] used B2O3 as a substitute for cuspidine in steel B2PB2) however, B2O3 content was extremely high (up to 30 w%). Other studies have investigated F-free mold flux by adding or optimizing components as MgO, Li2O, B2O3 et al[8-11]. However, most of these focused on the melting and viscosity issues or for low or ultra-low carbon steels, where crystallization tendency is not significantly strong. Very few studies regarding to the development of low/free Fluorine mold flux for casting medium carbon (MC) steels have been conducted, due to the difficulty of the crystallization and heat transfer control without the formation of cuspidine."

Jan 1, 2014

By D. P. Tripathy

A supply chain encompasses all the activities associated with the flow and transformation of goods from the raw materials stage(extraction), through to the end user. Supply chain management (SCM) is the integration of these activities through improved supply chain relationship, to achieve a sustainable competitive advantage and it rests on its ability to provide the right goods and services when and where needed. The supply chain is the vital component of any company?s value chain which links the operating processes to its supplier and customer. The globalization of business promises to offer new and unique challenges for the supply chain competencies of most firms. Challenges will also increase in the environmental aspects of supply chain often referred to as ?Green Issues?. The supply chain of mining industry comprises of the flow of material and information from the mine site, to processing and loading for transport, to the customer. However, due to recent changing environmental requirements affecting mining and mineral processing operations, increasing attention is given to developing environmental management (EM) strategies for the mineral supply chain. This paper focuses on: ? Environmental factors leading to the development of an extended environmental supply chain, ? Additional challenges presented by the extension, ? Performance measures appropriate for the extended supply chain, ? Developing a general procedure towards achieving and maintaining the green supply chain.

May 1, 2006

The Iscor Board has given its Mining Division the authority to proceed with detail engineering and design for a Heavy Minerals Project which comprises a mine in Northern Province near Gravelote, a mine in KwaZulu/Natal near Richards Bay and a central processing complex with a beneficiation plant and smelter which will be located near Richards Bay and Empangeni.

Jan 1, 1996

n interesting situation arose last week when two Vaal River residents wrote to me (and a third telephoned) giving me details of how Sasol wanted to develop an open-cast coal mine on the south bank of the Vaal, just upstream of the Barrage. This is agricultural land and is across the river from Millionaire?s Row, where a number of wealthy people have built river-side mansions. The mine would be hidden by a 30 m-high (10 storeys) earth wall set 300 m back from the edge of the river. It could operate 24 hours a day.

Jan 1, 1996

By Janet M. Epps

The international climate regulating environmental management in mining is rapidly evolving through the combined influences of the development of international guidelines, resolutions, protocols, treaties and conventions; the influences of the international lending and aid institutions who seek a consistent but constantly evolving standard of environmental performance from their clients; the legal precedents being developed in courts al over the world; and the activities of multinational countries who tend to rapidly upgrade technological performance through their international activities (particularly influencing developing countries). In this rapidly evolving regulatory environment, the more 'models' available to this international pool of resource materials that demonstrate practical. cost-effective and (most desirably) incentive based regulatory mechanisms, the better will be the eventual body of 'international standards' we will al have to work with. Australia can make a significant contribution to this process, however, it has only been on the margin of this dynamic, North American and European led process, up to this time. It is in the Australian minerals and energy industry's best interest to take an active part in the evolution and direction of this process.

Jan 1, 1996

Tracey Khanna, Assistant Editor of UK?s Mining Magazine discusses some of the new and important environmental challenges, physical and social, that are facing mining companies. The tide of public opinion has turned strongly against those companies which are unable to show that they are practising responsible environmental stewardship. This is, no doubt, in part due to the recent focus of the international media on environmental issues and constantly improving means of communications, which has brought the whole subject of mining and the environment to those who, in the past, had only a limited awareness of the industry. Mining companies today face new and important challenges with regard to the environment, both physical and social. New technology and a greater understanding of waste management techniques has helped to bring about improved handling and disposal of mines wastes, so reducing some of the impacts. However, improved technology has also brought about the economic viability of exploiting increasingly lower-grade ore from open pits, resulting in a greater visual impact.

Jan 1, 2000

This is an abstract from Environmental Service and Technology (Vol 32 No 20 1998) which will be o finterest to South African Mining and Metallurgical Scientists, involved in chromium mining and Metallurgical processing. Maybe the scourge of our dams and reservoirs?the water hyacinth can be put to good use! The novel technology of phytoremediation embraces plant accumulation processes for the cleanup of toxic heavy metals and organic chemicals. Several plant species have been identified that are excellent hyperaccumulators of a number of heavy metals, e.g., Brassica juncea (Indian mustard) and Thlaspe caerulescens (Alpine pennycress). Other speciesincluding Myriophyllum brasiliense(Parrot?s feather), Salixsp. (willow), and Popullussp. (poplar) have also demonstrated phytoremediating abilities.

Jan 1, 1999

The response was good-one of the best the SAIMM has had to its various questionnaires. 231 replies were received from 2768 members representing a response of 8,35%. For fellows and Members together, the response was 13,7%. The spread of responses based on respondents' work situation appeared to be well balanced with some bias from those in consulting organizations. Members' perceptions of their employers' positions withrespect to environmental management looked somewhat optimistic, but it is encouraging to note that they reported that more than half were developing environmental management systems. Training of varying degree was taking place at al levels in their organizations. Members saw their Institute as an important agent inlifting environmental awareness, literacy and responsibility not only through the journal and symposia, but also by liaison with government departments and educational institutions. Most respondents saw environmental legislation both from local and overseas sources as affecting their organizations, their products and services with the emphasis on corporate image, core business and sales.

Jan 1, 1995

A mining engineer from South Africa, whose research has taken him to some of the world?s deepest gold mines, is the winner of the St Andrews Prize. Daniel Limpitlaw, 27, picked up a cheque for $25,000 for his dissertation on reversing the damage done by early mining technology, which he claims is partly responsible for blighting the urban environment in many South African cities. Launched in October 1998 by the University of St Andrews and international energy company Conoco, the St Andrews Prize sought practical solutions to environmental problems. It attracted interest from 450 individuals and groups from countries as diverse as China, Pakistan, Canada, New Zealand, Germany, the UK and the United States.

Jan 1, 1999