1. As mechanised open cast iron ore mines becoming larger, deeper and more capital intensive, continuing efforts should be made to improve upon the open cast mining activities through advances in the equipment size / design and practices and also through introduction of innovative techniques. The application of high capacity continuous surface mining techniques to harder formations, new concept of high angle belt conveying system, in-pit crushing systems (mobile and semi-mobiles), high capacity dumpers, automatic truck dispatch system, non-electric blast initiation systems etc. and developments in the area of bulk explosive systems hold out almost unlimited opportunities for upgrading the performance of opencast iron ore mining in India, while minimizing the environmental impacts. In addition, the following proved cleaner technologies are need to be implemented in Indian iron ore mines, considering the suitability to the particular site:
• Adoption of Wet drilling
• Use of ripper dozer as an alternative to drilling and blasting
• Use of hydraulic hammer/rock breaker as an alternative to the secondary boulder blasting
• Use of opti blast technology and split charge blasting techniques wit air decking by the gas bags
• Use of non electric (NONEL) initiation devices (EXEL of ICI and RAYDET of IDL)
• Application of in-pit crushing and conveyor transport system as an alternative to all dumper transport system in deep mines
• Dry Fog dust control system at the crushing, screening & material handling/processing plant as an alternative to de-dusting system with bag-house
• Use of Hydro-cyclones and Slow Speed Classifiers in the wet beneficiation circuits to maximise the recovery of iron ore fines.
2. The reserves of high grade iron ore are limited. Therefore, it would be necessary at this stage to ensure conservation of high grade ore by blending with low grade ores. As a matter of policy, only low and medium grade iron ore, fines and only temporary surplus high grade iron ore (+67 % Fe), particularly from Bailadila (Chattisgarh) should be exported in the coming years. R&D efforts are needed for developing necessary technologies for utilising more and more fines in the production of steel as a measure of conservation of iron ores. Further, in the iron ore mines where wet processing of the ore is done, around 10-20% of ROM is lost as slimes depending on nature of ore feed, and in this context, coarser fines can be recovered up to 5 % by introducing hydrocycloning and slow speed classifiers in wet circuit system.
3. Efforts are also necessary to utilise the tailings/ waste as well. It has been found feasible to make bricks using 8 % of binding material such as cement and lime in slimes and 12 % in shale. A mixture of slimes and shale in the ratio of 4:1 by weight with 8% binder cement has reported to show good results in brick making. In the Bellary-Hospet area of Karnataka, the production of iron ore fines from the private mines is substantial, but the fines are unwashed and contain high fine percentage (40% of -100mesh fraction). In various R&D studies carried out so far, it has been found feasible to consume – 100 mesh fraction up to 30% blue dust in concentrate feed. The fines from Bellary-Hospet region generally have 63-64 % Fe content and if 100 mesh fractions can be limited to 3%, these fines can be used for sintering feed. In this regard the possibilities of setting up “Mine site” pelletising units are recommended wherever technically feasible on the lines of LTV (USA) TACONITE mines pelletising plants in North Minnesota.
4. The use of consistently appropriate mine planning is the most effective way to harmonise mining with the environment. No single element of mining, by itself, minimise environmental impacts. The first step in planning is to recognise the environmental issues that need to be faced during designing a feasible mine layout. It may range from air quality, noise and vibration, water management, water quality, soil conservation, flora and fauna, transport, rehabilitation, visual impacts, hazard and risk assessment, waste management to socio-economic issues. All the environmental considerations are to be firmly integrated into the planning of each stage of a mining project. It may further emphasized that there is a need for allocating adequate lease area for developing iron ore mining project and small scale mining should always be discouraged.
5. The underlying principle for effective pollution prevention and control is to contain contaminants on the site itself. This can include storing chemicals properly, avoiding unplanned equipment maintenance, etc. Air quality controls include the use of water tankers for dust suppression, water sprays on conveyors and ore stock piles, adopting controlled blasting techniques and limiting freefall distances while stockpiling the ores and overburdens. The design and maintenance of haul roads is also an important consideration in dust control. One of the critical factors in successful pollution prevention and control is through proper training of the workforce. It is no matter how sound the plant design or committed the mine management, ultimately environment protection can only be achieved with the understanding and commitment of the every person working in the mine.
NFLG, a professional manufacturer of mining equipment and ore progressing equipments obtains the trust of customers all over the world.
Mining and ore progressing equipment includes mining crusher, ore crusher such as jaw crusher , impact crusher , cone crusher , hammer crusher , VSI crusher, vertical shaft impact crusher, hydraulic crusher etc. In mining and ore progressing plants, jaw crusher is used as primary crushing equipment and cone crusher taking as secondary or final crusher machine. After crushing process, the crushed ore will be processed by grinding plant or washing plant etc.
NFLG can supply mining mill and ore mill with low price and high quality such as ball mill , Raymond mill , high pressure grinding mill , vertical mill , trapezium grinding mill etc.
If you want to get more information about mining and ore progressing, contact us: mill@unisbm.net or visit our website according to the online service 24 hours.
6. Noise, vibration and air blast are unavoidable fallouts of mining operations, which involve using large mobile equipment, fixed plant and blasting. Noise, vibration and airblast are among the most significant issues for communities located near mining projects. The adverse impacts due to noise, vibration and air blast emissions should be contained by the following three stage approach:
• Noise, vibration and air blast impact assessment.
• Developing and implementing a noise, vibration and air blast management plan.
• A monitoring and audit program.
7. Ore extraction and processing, workforce health and safety, and rehabilitation, all require water. Developing water management systems for a mine must account for site-specific physical, chemical and climatic characteristics as well as mine process factors. A minesite water management system consists of a number of physical elements to control the movement of clean and ‘dirty’ water onto, across and off the minesite, together with a number of process elements to control potential water problems at source, while maintaining and verifying the appropriate functioning of the water management system. It is essential that every effort should be made to avoid uncontrolled releases.
8. At present, approximately 14Mt of tailings are being generated per annum from the iron ore beneficiation. Management of such huge amount of tailings is important from control of pollution and resource conservation point of view. Normally tailings are being managed through impoundments in big settling ponds obstructed by big dams, more commonly known as tailings dam. The primary objective of the tailings dam is for the safe storage of tailings material and separation of water and solids. The detail guidelines for tailings dam construction and tailings management are discussed in section 5.2.6.
9. Climate, soils and the rehabilitation strategy are important considerations in minimising impacts on native flora and fauna. Soil erosion can be minimised by a proper understanding of soil structure, conservative landform design, utilising complex drainage networks, incorporating runoff silt traps and settling ponds in the rehabilitated landform. Careful use of topsoil can promote vegetation cover if the topsoil material is structurally appropriate and contains propagules of native vegetation. Selection of native floral species is desirable in promoting a stable and robust vegetation cover. Where possible, species endemic to the area should be used, preferably those from the site itself.
10. Ideally mine decommissioning should be planned at the commencement of operations. For the existing and long established iron ore mines in India, proper decommissioning to be integrated with the final year of mine operation. Final rehabilitation should be influenced by the long term post-mining land use and environmental condition of the site determined in consultation with the local community. Mine sites normally established transport links, heavy workshops and other infrastructure that can be put to a range of post-mining uses. Whether his is not the case or where restoration of pre-mining condition is required, hauls roads and buildings should be removed and the site rehabilitated and revegetated. One of the longer-term challenges is to ensure the safety and environmental appropriateness of final mining voids. It is, sometimes, possible to use these voids for disposal of surplus rejects and overburden from an adjoining mine, or to provide make up water and additional sedimentation capacity to other operations. A coordinated and planned approach to the issue of final voids for adjacent mines can significantly reduce environmental impacts.
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Recommended Management Practices and Cleaner Technologies in iron ore mining
1. As mechanised open cast iron ore mines becoming larger, deeper and more capital intensive, continuing efforts should be made to improve upon the open cast mining activities through advances in the equipment size / design and practices and also through introduction of innovative techniques. The application of high capacity continuous surface mining techniques to harder formations, new concept of high angle belt conveying system, in-pit crushing systems (mobile and semi-mobiles), high capacity dumpers, automatic truck dispatch system, non-electric blast initiation systems etc. and developments in the area of bulk explosive systems hold out almost unlimited opportunities for upgrading the performance of opencast iron ore mining in India, while minimizing the environmental impacts. In addition, the following proved cleaner technologies are need to be implemented in Indian iron ore mines, considering the suitability to the particular site:
• Adoption of Wet drilling
• Use of ripper dozer as an alternative to drilling and blasting
• Use of hydraulic hammer/rock breaker as an alternative to the secondary boulder blasting
• Use of opti blast technology and split charge blasting techniques wit air decking by the gas bags
• Use of non electric (NONEL) initiation devices (EXEL of ICI and RAYDET of IDL)
• Application of in-pit crushing and conveyor transport system as an alternative to all dumper transport system in deep mines
• Dry Fog dust control system at the crushing, screening & material handling/processing plant as an alternative to de-dusting system with bag-house
• Use of Hydro-cyclones and Slow Speed Classifiers in the wet beneficiation circuits to maximise the recovery of iron ore fines.
2. The reserves of high grade iron ore are limited. Therefore, it would be necessary at this stage to ensure conservation of high grade ore by blending with low grade ores. As a matter of policy, only low and medium grade iron ore, fines and only temporary surplus high grade iron ore (+67 % Fe), particularly from Bailadila (Chattisgarh) should be exported in the coming years. R&D efforts are needed for developing necessary technologies for utilising more and more fines in the production of steel as a measure of conservation of iron ores. Further, in the iron ore mines where wet processing of the ore is done, around 10-20% of ROM is lost as slimes depending on nature of ore feed, and in this context, coarser fines can be recovered up to 5 % by introducing hydrocycloning and slow speed classifiers in wet circuit system.
3. Efforts are also necessary to utilise the tailings/ waste as well. It has been found feasible to make bricks using 8 % of binding material such as cement and lime in slimes and 12 % in shale. A mixture of slimes and shale in the ratio of 4:1 by weight with 8% binder cement has reported to show good results in brick making. In the Bellary-Hospet area of Karnataka, the production of iron ore fines from the private mines is substantial, but the fines are unwashed and contain high fine percentage (40% of -100mesh fraction). In various R&D studies carried out so far, it has been found feasible to consume – 100 mesh fraction up to 30% blue dust in concentrate feed. The fines from Bellary-Hospet region generally have 63-64 % Fe content and if 100 mesh fractions can be limited to 3%, these fines can be used for sintering feed. In this regard the possibilities of setting up “Mine site” pelletising units are recommended wherever technically feasible on the lines of LTV (USA) TACONITE mines pelletising plants in North Minnesota.
4. The use of consistently appropriate mine planning is the most effective way to harmonise mining with the environment. No single element of mining, by itself, minimise environmental impacts. The first step in planning is to recognise the environmental issues that need to be faced during designing a feasible mine layout. It may range from air quality, noise and vibration, water management, water quality, soil conservation, flora and fauna, transport, rehabilitation, visual impacts, hazard and risk assessment, waste management to socio-economic issues. All the environmental considerations are to be firmly integrated into the planning of each stage of a mining project. It may further emphasized that there is a need for allocating adequate lease area for developing iron ore mining project and small scale mining should always be discouraged.
5. The underlying principle for effective pollution prevention and control is to contain contaminants on the site itself. This can include storing chemicals properly, avoiding unplanned equipment maintenance, etc. Air quality controls include the use of water tankers for dust suppression, water sprays on conveyors and ore stock piles, adopting controlled blasting techniques and limiting freefall distances while stockpiling the ores and overburdens. The design and maintenance of haul roads is also an important consideration in dust control. One of the critical factors in successful pollution prevention and control is through proper training of the workforce. It is no matter how sound the plant design or committed the mine management, ultimately environment protection can only be achieved with the understanding and commitment of the every person working in the mine.
NFLG, a professional manufacturer of mining equipment and ore progressing equipments obtains the trust of customers all over the world.
Mining and ore progressing equipment includes mining crusher, ore crusher such as jaw crusher , impact crusher , cone crusher , hammer crusher , VSI crusher, vertical shaft impact crusher, hydraulic crusher etc. In mining and ore progressing plants, jaw crusher is used as primary crushing equipment and cone crusher taking as secondary or final crusher machine. After crushing process, the crushed ore will be processed by grinding plant or washing plant etc.
NFLG can supply mining mill and ore mill with low price and high quality such as ball mill , Raymond mill , high pressure grinding mill , vertical mill , trapezium grinding mill etc.
If you want to get more information about mining and ore progressing, contact us: mill@unisbm.net or visit our website according to the online service 24 hours.
6. Noise, vibration and air blast are unavoidable fallouts of mining operations, which involve using large mobile equipment, fixed plant and blasting. Noise, vibration and airblast are among the most significant issues for communities located near mining projects. The adverse impacts due to noise, vibration and air blast emissions should be contained by the following three stage approach:
• Noise, vibration and air blast impact assessment.
• Developing and implementing a noise, vibration and air blast management plan.
• A monitoring and audit program.
7. Ore extraction and processing, workforce health and safety, and rehabilitation, all require water. Developing water management systems for a mine must account for site-specific physical, chemical and climatic characteristics as well as mine process factors. A minesite water management system consists of a number of physical elements to control the movement of clean and ‘dirty’ water onto, across and off the minesite, together with a number of process elements to control potential water problems at source, while maintaining and verifying the appropriate functioning of the water management system. It is essential that every effort should be made to avoid uncontrolled releases.
8. At present, approximately 14Mt of tailings are being generated per annum from the iron ore beneficiation. Management of such huge amount of tailings is important from control of pollution and resource conservation point of view. Normally tailings are being managed through impoundments in big settling ponds obstructed by big dams, more commonly known as tailings dam. The primary objective of the tailings dam is for the safe storage of tailings material and separation of water and solids. The detail guidelines for tailings dam construction and tailings management are discussed in section 5.2.6.
9. Climate, soils and the rehabilitation strategy are important considerations in minimising impacts on native flora and fauna. Soil erosion can be minimised by a proper understanding of soil structure, conservative landform design, utilising complex drainage networks, incorporating runoff silt traps and settling ponds in the rehabilitated landform. Careful use of topsoil can promote vegetation cover if the topsoil material is structurally appropriate and contains propagules of native vegetation. Selection of native floral species is desirable in promoting a stable and robust vegetation cover. Where possible, species endemic to the area should be used, preferably those from the site itself.
10. Ideally mine decommissioning should be planned at the commencement of operations. For the existing and long established iron ore mines in India, proper decommissioning to be integrated with the final year of mine operation. Final rehabilitation should be influenced by the long term post-mining land use and environmental condition of the site determined in consultation with the local community. Mine sites normally established transport links, heavy workshops and other infrastructure that can be put to a range of post-mining uses. Whether his is not the case or where restoration of pre-mining condition is required, hauls roads and buildings should be removed and the site rehabilitated and revegetated. One of the longer-term challenges is to ensure the safety and environmental appropriateness of final mining voids. It is, sometimes, possible to use these voids for disposal of surplus rejects and overburden from an adjoining mine, or to provide make up water and additional sedimentation capacity to other operations. A coordinated and planned approach to the issue of final voids for adjacent mines can significantly reduce environmental impacts.