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Three case studies present the use of new or unconventional technology to improve sustainability and reduce residue management costs at different stages of mine life. The first relates to a US Cu operation closed in the 1970s apart from leaching of a low-grade stockpile; when the declining solution grade made solvent extraction-electrowinning uneconomic, installation in 2004 of a Cu recovery plant using BioteQ's BioSulphide process allowed cost-effective Cu recovery to continue for an additional nine years. The process uses H2S gas generated in a bioreactor to precipitate metals from water. The plant was designed to produce up to 3.8 t/d sulphide by treating up to 12 000 m3/d of leach solution at a design Cu recovery rate of 99%, the treated solution being recycled to the top of the stockpile. The second concerns a Cu smelter in Chile where the As content of Cu concentrate has gradually increased, leading to off-gas As during smelting reporting to water-based scrubbers which then produce highly acidic As-rich liquid blow-down (EPAS). The BioSulphide process was implemented to treat the EPAS solution instead of lime neutralisation. Benefits included a significant reduction in the volume of waste residue generated, the metal sulphide residue with more than 50% w/w As on a dry-weight basis offering an order of magnitude reduction in solids handling and disposal costs. Power and chemical costs are reduced, water recovery is higher, acid contained in EPAS is recovered and the recovery of metals such as Cu, Re and Mo from EPAS becomes a possibility. The third case study involves a large Cu-Au mine currently being permitted in a sensitive watershed area where water treatment is being carefully evaluated with particular regard to Se in the ore body, overburden and waste. A pilot project was undertaken using BioteQ's Selen-IX Se treatment system. A strong-base anion-exchange resin in the sulphate form is used to remove Se selectively from water to concentrations of less than, Three case studies present the use of new or unconventional technology to improve sustainability and reduce residue management costs at different stages of mine life. The first relates to a US Cu operation closed in the 1970s apart from leaching of a low-grade stockpile; when the declining solution grade made solvent extraction-electrowinning uneconomic, installation in 2004 of a Cu recovery plant using BioteQ's BioSulphide process allowed cost-effective Cu recovery to continue for an additional nine years. The process uses H2S gas generated in a bioreactor to precipitate metals from water. The plant was designed to produce up to 3.8 t/d sulphide by treating up to 12 000 m3/d of leach solution at a design Cu recovery rate of 99%, the treated solution being recycled to the top of the stockpile. The second concerns a Cu smelter in Chile where the As content of Cu concentrate has gradually increased, leading to off-gas As during smelting reporting to water-based scrubbers which then produce highly acidic As-rich liquid blow-down (EPAS). The BioSulphide process was implemented to treat the EPAS solution instead of lime neutralisation. Benefits included a significant reduction in the volume of waste residue generated, the metal sulphide residue with more than 50% w/w As on a dry-weight basis offering an order of magnitude reduction in solids handling and disposal costs. Power and chemical costs are reduced, water recovery is higher, acid contained in EPAS is recovered and the recovery of metals such as Cu, Re and Mo from EPAS becomes a possibility. The third case study involves a large Cu-Au mine currently being permitted in a sensitive watershed area where water treatment is being carefully evaluated with particular regard to Se in the ore body, overburden and waste. A pilot project was undertaken using BioteQ's Selen-IX Se treatment system. A strong-base anion-exchange resin in the sulphate form is used to remove Se selectively from water to concentrations of less than

The purpose of this research is to investigate the effects of social and organizational identifications on student commitment, achievement and satisfaction in higher education. The sample comprised 437 students enrolled in an undergraduate or postgraduate programme in business or management. A model was developed and tested using structural equation modelling. It was found that organizational identification is a stronger predictor of student commitment, achievement and satisfaction than social identification. Although organizational identification was a strong predictor of student satisfaction, student commitment was better at explaining student achievement. The implications for higher education institutions are discussed. To the knowledge of the authors, this is the first study to examine the effects of organizational identification on student commitment, achievement and satisfaction. The key contribution of the research is in providing support for the hypothesis that organizational identification can influence the attitudes and behaviour of higher education students, as it has been shown to do with employees and consumers.

The SART process was developed in the late 1990s by SGS Lakefield and Teck Corporation for the treatment of gold ores containing cyanide-soluble copper. Despite being a cost-effective process for the treatment of such ore bodies, acceptance of the process has been slow. BioteQ incorporates risk mitigation into the project development plan, so showing that the process can be applied safely and cost-effectively. The paper covers three areas where there are safety concerns. The first is the control of the HCN gas evolved during the acidification of the leach solution by means of plant design and the use of personal protective equipment for the operators. The other two are the overall technical control of the plant and the risks associated with project execution., The SART process was developed in the late 1990s by SGS Lakefield and Teck Corporation for the treatment of gold ores containing cyanide-soluble copper. Despite being a cost-effective process for the treatment of such ore bodies, acceptance of the process has been slow. BioteQ incorporates risk mitigation into the project development plan, so showing that the process can be applied safely and cost-effectively. The paper covers three areas where there are safety concerns. The first is the control of the HCN gas evolved during the acidification of the leach solution by means of plant design and the use of personal protective equipment for the operators. The other two are the overall technical control of the plant and the risks associated with project execution.

Processes are described that have been developed by BioteQ Environmental Technologies to produce treated water that can be safely discharged to the environment or recycled and saleable metal products such as Zn, Cu, Ni and Co to help offset treatment costs. In the BioSulphide process H2S is generated by the reduction of elemental S in an aerobic bioreactor and used to selectively precipitate heavy metals such as Cu, Zn, Ni and Co in an agitated contactor reactor. The metal sulphides are recovered by clarification and filtration. The ChemSulphide process uses chemical sulphide reagent and is employed in smaller applications. Benefits of the process are illustrated with reference to its use at the Raglan mine in Canada. Pilot studies have been completed of an ion exchange-based technology for sulphate removal from mine wastewater to meet stricter effluent sulphate limits or for process water recycling., Processes are described that have been developed by BioteQ Environmental Technologies to produce treated water that can be safely discharged to the environment or recycled and saleable metal products such as Zn, Cu, Ni and Co to help offset treatment costs. In the BioSulphide process H2S is generated by the reduction of elemental S in an aerobic bioreactor and used to selectively precipitate heavy metals such as Cu, Zn, Ni and Co in an agitated contactor reactor. The metal sulphides are recovered by clarification and filtration. The ChemSulphide process uses chemical sulphide reagent and is employed in smaller applications. Benefits of the process are illustrated with reference to its use at the Raglan mine in Canada. Pilot studies have been completed of an ion exchange-based technology for sulphate removal from mine wastewater to meet stricter effluent sulphate limits or for process water recycling.

BioteQ Environmental Technologies has successfully demonstrated in industrial plants that biogenic sulphide reagent can be generated cost- effectively and used to win metals such as copper, zinc and nickel from low-grade leach solutions and waste water. The BioSulphide process is used to recover Zn-Cu-Cd at the Caribou mine, New Brunswick, Cu at the Bisbee project, Copper Queen mine, Arizona, and is to be used to recover Cu at Dexing mine, Jiangxi. New applications are to recover Cu from Au cyanide in the SART process, regenerating the cyanide, and possibly to replace sodium hydrosulphide in flotation of Cu from Mo., BioteQ Environmental Technologies has successfully demonstrated in industrial plants that biogenic sulphide reagent can be generated cost- effectively and used to win metals such as copper, zinc and nickel from low-grade leach solutions and waste water. The BioSulphide process is used to recover Zn-Cu-Cd at the Caribou mine, New Brunswick, Cu at the Bisbee project, Copper Queen mine, Arizona, and is to be used to recover Cu at Dexing mine, Jiangxi. New applications are to recover Cu from Au cyanide in the SART process, regenerating the cyanide, and possibly to replace sodium hydrosulphide in flotation of Cu from Mo.

Details are given of a new plant for the recovery of Cu from low grade leach solutions at the Copper Queen Mine, Bisbee, Arizona. The plant employs BioteQ's BioSulphide process, which uses a high rate anaerobic biotechnology for the on-site production of H2S from elemental sulphur. The biogenic sulphide reagent produced is used to precipitate copper into a high-grade copper sulphide concentrate from the pregnant leach solution draining from a low-grade stockpile. The operation is one of three commercial plants using the technology for metal recovery (Cu, Ni and Co) and/or to produce high quality water for environmental discharge, and another is under construction. The environmental and economic benefits are discussed using data from the existing operations., Details are given of a new plant for the recovery of Cu from low grade leach solutions at the Copper Queen Mine, Bisbee, Arizona. The plant employs BioteQ's BioSulphide process, which uses a high rate anaerobic biotechnology for the on-site production of H2S from elemental sulphur. The biogenic sulphide reagent produced is used to precipitate copper into a high-grade copper sulphide concentrate from the pregnant leach solution draining from a low-grade stockpile. The operation is one of three commercial plants using the technology for metal recovery (Cu, Ni and Co) and/or to produce high quality water for environmental discharge, and another is under construction. The environmental and economic benefits are discussed using data from the existing operations.

This paper reports the BioSulphide process for the on-site production of hydrogen sulphide for water treatment and recovery of metal. This is a high-rate anaerobic biotechnology. There is particular focus on operations at the Raglan mine in northern Quebec, where dissolved nickel is removed from contaminated water. New projects outlined are at Blackwell in Oklahoma, Wellington Oro in Colorado and Britannia in British Columbia., This paper reports the BioSulphide process for the on-site production of hydrogen sulphide for water treatment and recovery of metal. This is a high-rate anaerobic biotechnology. There is particular focus on operations at the Raglan mine in northern Quebec, where dissolved nickel is removed from contaminated water. New projects outlined are at Blackwell in Oklahoma, Wellington Oro in Colorado and Britannia in British Columbia.

The successful development of commercial operations for acid rock drainage treatment and selective metal recovery using the BioSulphide and Thiopaq biological reduction technologies is described. The process was developed to provide biogenic sulphide for the selective recovery of high purity-metal concentrates from acidic waste water. The process can be used on a stand-alone basis or in conjunction with a lime circuit. Process advantages include selective recovery of metals, very low metal concentrations in effluent, reduced waste sludge liability, reduced lime treatment costs and, in some cases, profitable sale of metal concentrates. Two case studies are presented focusing on metal recovery at the Caribou mine, New Brunswick, and at Phelps Dodge's Bisbee, Arizona. A third highlights environmental control as well as metal recovery at Raglan mine in Quebec. Process flowsheets as well as capital and operating costs are presented., The successful development of commercial operations for acid rock drainage treatment and selective metal recovery using the BioSulphide and Thiopaq biological reduction technologies is described. The process was developed to provide biogenic sulphide for the selective recovery of high purity-metal concentrates from acidic waste water. The process can be used on a stand-alone basis or in conjunction with a lime circuit. Process advantages include selective recovery of metals, very low metal concentrations in effluent, reduced waste sludge liability, reduced lime treatment costs and, in some cases, profitable sale of metal concentrates. Two case studies are presented focusing on metal recovery at the Caribou mine, New Brunswick, and at Phelps Dodge's Bisbee, Arizona. A third highlights environmental control as well as metal recovery at Raglan mine in Quebec. Process flowsheets as well as capital and operating costs are presented.

The SART (sulphidisation-acidification-recycle-thickening) process was originally developed for the treatment of barren leach solutions containing copper cyanide complexes. The treatment involves the use of sulphuric acid and a sulphide reagent to precipitate copper as copper sulphide which is then thickened and recovered as a valuable high-grade concentrate. BioteQ has been involved in developing the process through a number of projects using either chemical or biogenetically produced sulphide reagents. The recovery of gold from copper-gold ores has historically resulted in high cyanide consumption, poor gold recovery and environmental issues associated with the presence of cyanide in the tailings supernatant, but recent developments in SART technology have provided solutions to these issues and enabled mining companies to consider the development of projects once considered challenging from an economic and environmental standpoint. SART can be applied to gold-copper orebodies to maximise gold recovery, minimise copper cyanide formation and recover the associated cyanide for recycling to the gold leaching process. The removal of copper also reduces cyanide detoxification costs and eliminates the disposal of copper cyanide with tailings. The technology is safe, efficient and easily controlled., The SART (sulphidisation-acidification-recycle-thickening) process was originally developed for the treatment of barren leach solutions containing copper cyanide complexes. The treatment involves the use of sulphuric acid and a sulphide reagent to precipitate copper as copper sulphide which is then thickened and recovered as a valuable high-grade concentrate. BioteQ has been involved in developing the process through a number of projects using either chemical or biogenetically produced sulphide reagents. The recovery of gold from copper-gold ores has historically resulted in high cyanide consumption, poor gold recovery and environmental issues associated with the presence of cyanide in the tailings supernatant, but recent developments in SART technology have provided solutions to these issues and enabled mining companies to consider the development of projects once considered challenging from an economic and environmental standpoint. SART can be applied to gold-copper orebodies to maximise gold recovery, minimise copper cyanide formation and recover the associated cyanide for recycling to the gold leaching process. The removal of copper also reduces cyanide detoxification costs and eliminates the disposal of copper cyanide with tailings. The technology is safe, efficient and easily controlled.

The recovery of metals from waste water can potentially generate revenue to offset water treatment costs. Solvent extraction/electrowinning is only employed for streams with very large mass loadings of recoverable metals, due to its high capital and operating costs and low efficiency at low metal concentrations. Electrometals/electrowinning (EMEW) which allows direct electrowinning without solvent extraction, employs a pair of tubular rather than planar electrodes in which the outer cathode and centrally placed anode are capped to form a cylinder through which the solution is pumped. The waste stream produced contains residual dissolved metal that requires treatment, and other limitations are that not all metals can be efficiently won, the presence of certain metals such as Fe can reduce current efficiency and increase operating costs, and the current density is relatively low. Lime treatment is easy to engineer and simple to operate and is cost-effective for treating large volumes of waste water which are not subject to strict discharge limits. It is also effective where the main contaminants are dissolved Al or Fe as the sludge formed is non-toxic, but for sites with heavy metals sludge management is a significant long-term environmental and financial liability. Reverse osmosis can be used to meet strict water quality criteria but is more costly and inefficient and produces a liquid brine stream that requires special handling. Reverse osmosis/membrane systems are best for sites with very low dissolved metal concentrations, but they also tend to result in more acidic water which may be harmful to the environment, so that neutralisation is required before discharge or re-use. Ion exchange is particularly effective where metal concentrations are low but still exceed discharge limits. Sulphide precipitation systems such as BioSulphide and Chemsulphide can be used to precipitate metals selectively and can treat large flows of water containing relatively low concentrati, The recovery of metals from waste water can potentially generate revenue to offset water treatment costs. Solvent extraction/electrowinning is only employed for streams with very large mass loadings of recoverable metals, due to its high capital and operating costs and low efficiency at low metal concentrations. Electrometals/electrowinning (EMEW) which allows direct electrowinning without solvent extraction, employs a pair of tubular rather than planar electrodes in which the outer cathode and centrally placed anode are capped to form a cylinder through which the solution is pumped. The waste stream produced contains residual dissolved metal that requires treatment, and other limitations are that not all metals can be efficiently won, the presence of certain metals such as Fe can reduce current efficiency and increase operating costs, and the current density is relatively low. Lime treatment is easy to engineer and simple to operate and is cost-effective for treating large volumes of waste water which are not subject to strict discharge limits. It is also effective where the main contaminants are dissolved Al or Fe as the sludge formed is non-toxic, but for sites with heavy metals sludge management is a significant long-term environmental and financial liability. Reverse osmosis can be used to meet strict water quality criteria but is more costly and inefficient and produces a liquid brine stream that requires special handling. Reverse osmosis/membrane systems are best for sites with very low dissolved metal concentrations, but they also tend to result in more acidic water which may be harmful to the environment, so that neutralisation is required before discharge or re-use. Ion exchange is particularly effective where metal concentrations are low but still exceed discharge limits. Sulphide precipitation systems such as BioSulphide and Chemsulphide can be used to precipitate metals selectively and can treat large flows of water containing relatively low concentrati