This document summarizes chromite mining practices on the Great Dyke in Zimbabwe. It describes the current resue stoping method used to mine chromite seams, which involves drilling and blasting waste rock and carefully lifting the chromite ore. It also discusses previous attempts at mechanization that failed. Future mining methods being considered include narrow reef stoping where all material is hoisted out without waste packing, requiring new shaft and layout designs to accommodate increased waste rock hoisting.
The document discusses the challenges of extracting coal from underground mines that have been developed with pillars, by using opencast mining methods. It notes that as opencast mines deplete virgin coal seams, developed underground pillars will be an important future source of coal. However, extracting coal from these areas poses risks like coal dust explosions, fires, and miners falling into unstable voids ("pot holes"). The document outlines safety guidelines from DGMS for working in areas with underground development, including maintaining minimum partings above galleries, controlled blasting procedures, and isolating active underground areas. It also describes the processes used to systematically extract coal from developed pillars, including delineating zones of increasing risk and ensuring ground control through compaction before
Practical importance of the Room and pillars method; Different applications of the R & P method; R & P in hard rocks; Conditions of deposit for application of R & P in hard rock; R & P equipment in hard-rock; R & P in soft rocks; Conditions of deposit for application of R & P in soft rock; Characteristics of R & P method in non-coal applications; R & P classic;Step mining; Post-pillar mining; Configuring the R & P method in coal; Main design parameters of R & P in coal; dimensions of the galleries; dimensions of the pillars; Mining with or without recovery of pillars; number of front panel; Advantages and Disadvantages; Screws Ceiling; Design of pillars in coal mine
This document provides an overview of open-pit mining basics. It discusses that open-pit mining, also called surface mining, extracts ore or minerals from the ground without tunneling underground. The document outlines the two main types of mining as surface mining and subsurface mining. It also provides details on open-pit mining methods, factors for selecting mining methods, advantages and disadvantages of open-pit mining, and the key operations involved in open-pit mining.
Criteria for selection of Board and pillar for multiple seamsAsim kumar Satapathy
So the main purpose of this project is to focus on the selection criteria of Bord and Pillar workings without compromising the safety factor in multiple seam.
This document discusses different surface mining methods. It describes strip mining, terrace mining, and open-pit mining. Strip mining is used for relatively horizontal deposits with thin overburden. Terrace mining uses multiple benches when overburden is too thick for waste to be dumped in the pit. Open-pit mining is used for steeply dipping, pipe-shaped or irregular deposits where waste must be dumped outside the excavation area. Examples of each method are provided.
Limestone mining can negatively impact the environment in several ways. A case study of limestone mining in the Katni River watershed of Madhya Pradesh, India found that: (1) Opencast limestone mines increased calcium levels and total hardness in groundwater, degrading local water quality beyond standards. (2) Mines located in higher elevation areas caused turbid runoff that polluted downstream areas. (3) Within 11 years, calcium levels in the area increased by over 100% and hardness by over 500% due to limestone mining impacts on groundwater. Strict preventative measures are needed to curb further pollution from mining.
This document discusses coal mining methods. It begins with an introduction and overview of the history of coal mining. It then describes and compares various surface mining techniques like strip mining and horizon mining as well as underground mining methods like bord and pillar, longwall and shortwall. Factors that influence the selection of mining methods and latest developments in coal mining techniques are also summarized. The conclusion restates that coal is an important energy source and mining methods continue to evolve and improve.
This document discusses extraction of coal pillars using open cast mining methods. It outlines several open cast mines where pillar extraction is occurring and provides reasons for converting underground mines to open cast, including higher coal recovery rates and lower production costs with open cast mining. The document then discusses challenges with conversion like gallery collapse and fire risks, and provides details on survey procedures, zone demarcation, drilling and blasting patterns, and safety precautions used to effectively compact underground galleries during conversion to prevent collapse.
The document discusses the challenges of extracting coal from underground mines that have been developed with pillars, by using opencast mining methods. It notes that as opencast mines deplete virgin coal seams, developed underground pillars will be an important future source of coal. However, extracting coal from these areas poses risks like coal dust explosions, fires, and miners falling into unstable voids ("pot holes"). The document outlines safety guidelines from DGMS for working in areas with underground development, including maintaining minimum partings above galleries, controlled blasting procedures, and isolating active underground areas. It also describes the processes used to systematically extract coal from developed pillars, including delineating zones of increasing risk and ensuring ground control through compaction before
Practical importance of the Room and pillars method; Different applications of the R & P method; R & P in hard rocks; Conditions of deposit for application of R & P in hard rock; R & P equipment in hard-rock; R & P in soft rocks; Conditions of deposit for application of R & P in soft rock; Characteristics of R & P method in non-coal applications; R & P classic;Step mining; Post-pillar mining; Configuring the R & P method in coal; Main design parameters of R & P in coal; dimensions of the galleries; dimensions of the pillars; Mining with or without recovery of pillars; number of front panel; Advantages and Disadvantages; Screws Ceiling; Design of pillars in coal mine
This document provides an overview of open-pit mining basics. It discusses that open-pit mining, also called surface mining, extracts ore or minerals from the ground without tunneling underground. The document outlines the two main types of mining as surface mining and subsurface mining. It also provides details on open-pit mining methods, factors for selecting mining methods, advantages and disadvantages of open-pit mining, and the key operations involved in open-pit mining.
Criteria for selection of Board and pillar for multiple seamsAsim kumar Satapathy
So the main purpose of this project is to focus on the selection criteria of Bord and Pillar workings without compromising the safety factor in multiple seam.
This document discusses different surface mining methods. It describes strip mining, terrace mining, and open-pit mining. Strip mining is used for relatively horizontal deposits with thin overburden. Terrace mining uses multiple benches when overburden is too thick for waste to be dumped in the pit. Open-pit mining is used for steeply dipping, pipe-shaped or irregular deposits where waste must be dumped outside the excavation area. Examples of each method are provided.
Limestone mining can negatively impact the environment in several ways. A case study of limestone mining in the Katni River watershed of Madhya Pradesh, India found that: (1) Opencast limestone mines increased calcium levels and total hardness in groundwater, degrading local water quality beyond standards. (2) Mines located in higher elevation areas caused turbid runoff that polluted downstream areas. (3) Within 11 years, calcium levels in the area increased by over 100% and hardness by over 500% due to limestone mining impacts on groundwater. Strict preventative measures are needed to curb further pollution from mining.
This document discusses coal mining methods. It begins with an introduction and overview of the history of coal mining. It then describes and compares various surface mining techniques like strip mining and horizon mining as well as underground mining methods like bord and pillar, longwall and shortwall. Factors that influence the selection of mining methods and latest developments in coal mining techniques are also summarized. The conclusion restates that coal is an important energy source and mining methods continue to evolve and improve.
This document discusses extraction of coal pillars using open cast mining methods. It outlines several open cast mines where pillar extraction is occurring and provides reasons for converting underground mines to open cast, including higher coal recovery rates and lower production costs with open cast mining. The document then discusses challenges with conversion like gallery collapse and fire risks, and provides details on survey procedures, zone demarcation, drilling and blasting patterns, and safety precautions used to effectively compact underground galleries during conversion to prevent collapse.
This document discusses coal mining methods. It describes the objectives of coal prospecting and exploration. There are two main mining methods: underground and surface mining. The choice depends on factors like depth below surface and ore body shape and grade. Underground mining is used when the deposit is deep or the ore body is steep. It involves cutting rooms into the coal seam. Surface mining is used for large, high production deposits where the overburden is thin. It involves clearing vegetation, removing topsoil, drilling, blasting, and reclaiming the land.
An open pit mine is an excavation made at the surface of the ground to extract ore throughout the life of the mine. Large quantities of waste rock must be excavated and relocated to access and mine the ore deposit. The planning of an open pit mine aims to exploit the mineral deposit at the lowest cost while maximizing profits, through optimizing the physical design and scheduling of ore and waste extraction. Ore and waste materials are removed in successive layers called benches, with several benches potentially in operation simultaneously at different elevations in the open pit mine.
Open pit mining, also called surface mining, involves excavating minerals or rock that are close to the surface. There are two main types of mining methods: underground mining, which excavates deeper deposits; and surface mining, where the deposits are closer to the surface. Open pit mining involves digging a pit on the surface to extract near-surface mineral deposits through horizontal benches. It is best suited for deposits that are no deeper than 300 meters and have a low ratio of overburden rock to ore. The process involves site preparation, drilling and blasting of overburden rock, removing overburden with heavy machinery, excavating and transporting ore, and reclaiming the land after mining is complete.
There are two main methods for coal mining - surface or open-cast mining and underground mining. The choice of method depends on the depth of the coal deposit and thickness of material overlying it. Underground mining involves digging inclined or vertical entry tunnels into the deposit without removing the overburden rock, and then mining the coal using various methods like bord and pillar, longwall mining, etc. Open-cast mining involves removing the overburden rock and then excavating the coal deposits using equipment like shovels, draglines, surface miners. Singareni Collieries Company Ltd (SCCL) is one of the major coal producers in India operating in Godavari Valley coalfields of Andhra Pradesh since 1889.
Introduction; Application of Cut-and-Fill (C & F) stoping; The activity cycle of the (C & F) method; Stages of the production cycle of the C & F method; Sequences of extracting ore bodies; Filling in C & F Method; About filling of stopes; Functions of filler; Types of fillers; Advantages and disadvantages of the C & F method
This document provides an introduction and overview of Dr. Andrew Cox's Coal Lectures Series. The series covers topics related to coal formation, properties, use as a fuel, mining technologies, markets, pollution control, and more. Dr. Cox and colleagues at EIMR can provide lectures on these topics to university courses and professional development programs in the UK and internationally. Interested parties should contact Dr. Cox for more information. An introductory presentation on coal mining technologies is also included as an example of the type of material covered.
Open pit mining is the process of mining a near surface deposit by means of a surface pit excavated using one or more horizontal benches.
The term open pit mining is usually used for metallic or non-metallic deposits and sparingly used for bedded deposits like coal.
The document discusses open pit mining methods. Open pit mines are used to extract low grade, shallow ore bodies and can mine over 20,000 tonnes per day. They produce two waste streams: waste rock with no economic minerals, and tailings from mineral processing. Pit design considers factors like haul roads, equipment size, pit slopes, and water control. Examples discussed include the large open pit copper mines at Bagdad, Arizona and Highland Valley, British Columbia. Pushbacks are required to deepen the pit by first removing waste rock to access deeper ore zones. Benches are cut into pit walls to achieve steeper yet stable slopes.
This document discusses two mining methods: step mining and post-pillar mining. Step mining involves creating horizontal floors to allow equipment use for deposits that are too steeply inclined. Post-pillar mining uses regularly spaced pillars to extract inclined deposits between 20-55 degrees and allows filling of the mined space. It also discusses considerations for gallery dimensions, pillar dimensions and configurations, recovery strategies, equipment used, and operational aspects of board and pillar mining.
This document provides an overview of various surface mining methods. It begins by defining surface mining as extracting ore that lies near the surface by removing overburden. It then discusses the history of surface mining and factors to consider for evaluating surface deposits, including geography, legal issues, and economics. Specific surface mining methods covered include placer mining using panning, sluicing, hydraulicking, and dredging, as well as strip mining and open pit mining.
Opencast mining, also called open-pit or open-cut mining, involves removing mineral resources from the earth through large pits or holes dug on the surface. It has advantages like high coal extraction rates, mechanization, and fewer safety hazards than underground mining. However, it also causes issues like land degradation, deforestation, water and air pollution, and unpleasant sights from mining areas. Proper bench design, berms, haul road gradients, and safety measures are important for effective and safe opencast mining operations.
This document discusses underground coal mining methods and operations. It begins by describing different means of accessing underground coal seams, such as adits, shafts, and cross measure drifts. Factors to consider in selecting an access method include coal clearance, ventilation, topography, overburden depth, and costs. It then discusses development work, including driving main roadways and cut-throughs, and the equipment used like continuous miners and roof bolters. Pillars are left behind to support the mine openings, including barrier pillars to separate panels and chain pillars to control subsidence during longwall mining.
The document discusses various mining methods for steeply dipping and massive ore deposits. It describes caving methods like sublevel caving and induced block caving that are suitable for massive deposits with low ore value. It also outlines self-supported methods including sublevel stoping and large open stope mining. Supported methods such as cut-and-fill stoping and undercut-and-fill stoping are described as well. Each method is examined in terms of its applications, advantages, and disadvantages.
This document provides an overview of open pit mining technologies used in coal mines operated by SCCL in India. It discusses the key types of surface and subsurface mining methods. For open pit mining, it describes various mechanized methods used including shovel-dumper combinations, draglines, and bucket wheel excavators. It also outlines the ideal conditions for open pit mining and discusses operations involving stripping, drilling, blasting, extraction, and transport of coal. Pit design considerations like bench dimensions and slope angles are also summarized.
Open-pit mines are used when commercially useful minerals or rock deposits are near the surface and overburden is thin, as they are more economical than tunnel mining. Ore is extracted from successive vertical benches in the open pit until resources are depleted or overburden costs rise. Exhausted open pits are sometimes converted to landfills but may require water control to prevent flooding and formation of lakes.
This document discusses the Bord and Pillar method of coal mining. It involves leaving pillars of coal as support during initial mining, allowing for around 20% output. Later, the pillars can be extracted to increase output to 60%. The document focuses on the process of depillaring, or extracting the remaining coal from the pillars. This involves techniques like depillaring with stowing, where the emptied areas are filled with incombustible materials to control subsidence. Principles of safe pillar extraction are outlined, along with case studies and conclusions that depillaring must be done scientifically and safely according to regulations.
Open-pit mining involves digging huge portions of earth from the surface to extract desired minerals. The land face is scraped away through explosives and digging, creating a deeper pit until mining is complete. Open-pit mining has several levels of excavation displaying varying visuals as miners dig further. The process involves designing mining layouts, drilling, blasting, clearing blasts, digging, transporting ore, and cleaning up. While more efficient than underground mining, open-pit mining degrades the environment through destruction of habitat, dust, chemical pollution, and exposure of soil.
8.Monitoring process By Mr Allah Dad Khan Provincial Project Director CMP I...Mr.Allah Dad Khan
Monitoring is an important process to ensure quality and compliance. It involves regularly and closely observing a situation, system, or process to identify any issues or areas for improvement. Effective monitoring helps organizations achieve their goals and objectives on time and within budget by identifying and addressing problems early.
This document discusses coal mining methods. It describes the objectives of coal prospecting and exploration. There are two main mining methods: underground and surface mining. The choice depends on factors like depth below surface and ore body shape and grade. Underground mining is used when the deposit is deep or the ore body is steep. It involves cutting rooms into the coal seam. Surface mining is used for large, high production deposits where the overburden is thin. It involves clearing vegetation, removing topsoil, drilling, blasting, and reclaiming the land.
An open pit mine is an excavation made at the surface of the ground to extract ore throughout the life of the mine. Large quantities of waste rock must be excavated and relocated to access and mine the ore deposit. The planning of an open pit mine aims to exploit the mineral deposit at the lowest cost while maximizing profits, through optimizing the physical design and scheduling of ore and waste extraction. Ore and waste materials are removed in successive layers called benches, with several benches potentially in operation simultaneously at different elevations in the open pit mine.
Open pit mining, also called surface mining, involves excavating minerals or rock that are close to the surface. There are two main types of mining methods: underground mining, which excavates deeper deposits; and surface mining, where the deposits are closer to the surface. Open pit mining involves digging a pit on the surface to extract near-surface mineral deposits through horizontal benches. It is best suited for deposits that are no deeper than 300 meters and have a low ratio of overburden rock to ore. The process involves site preparation, drilling and blasting of overburden rock, removing overburden with heavy machinery, excavating and transporting ore, and reclaiming the land after mining is complete.
There are two main methods for coal mining - surface or open-cast mining and underground mining. The choice of method depends on the depth of the coal deposit and thickness of material overlying it. Underground mining involves digging inclined or vertical entry tunnels into the deposit without removing the overburden rock, and then mining the coal using various methods like bord and pillar, longwall mining, etc. Open-cast mining involves removing the overburden rock and then excavating the coal deposits using equipment like shovels, draglines, surface miners. Singareni Collieries Company Ltd (SCCL) is one of the major coal producers in India operating in Godavari Valley coalfields of Andhra Pradesh since 1889.
Introduction; Application of Cut-and-Fill (C & F) stoping; The activity cycle of the (C & F) method; Stages of the production cycle of the C & F method; Sequences of extracting ore bodies; Filling in C & F Method; About filling of stopes; Functions of filler; Types of fillers; Advantages and disadvantages of the C & F method
This document provides an introduction and overview of Dr. Andrew Cox's Coal Lectures Series. The series covers topics related to coal formation, properties, use as a fuel, mining technologies, markets, pollution control, and more. Dr. Cox and colleagues at EIMR can provide lectures on these topics to university courses and professional development programs in the UK and internationally. Interested parties should contact Dr. Cox for more information. An introductory presentation on coal mining technologies is also included as an example of the type of material covered.
Open pit mining is the process of mining a near surface deposit by means of a surface pit excavated using one or more horizontal benches.
The term open pit mining is usually used for metallic or non-metallic deposits and sparingly used for bedded deposits like coal.
The document discusses open pit mining methods. Open pit mines are used to extract low grade, shallow ore bodies and can mine over 20,000 tonnes per day. They produce two waste streams: waste rock with no economic minerals, and tailings from mineral processing. Pit design considers factors like haul roads, equipment size, pit slopes, and water control. Examples discussed include the large open pit copper mines at Bagdad, Arizona and Highland Valley, British Columbia. Pushbacks are required to deepen the pit by first removing waste rock to access deeper ore zones. Benches are cut into pit walls to achieve steeper yet stable slopes.
This document discusses two mining methods: step mining and post-pillar mining. Step mining involves creating horizontal floors to allow equipment use for deposits that are too steeply inclined. Post-pillar mining uses regularly spaced pillars to extract inclined deposits between 20-55 degrees and allows filling of the mined space. It also discusses considerations for gallery dimensions, pillar dimensions and configurations, recovery strategies, equipment used, and operational aspects of board and pillar mining.
This document provides an overview of various surface mining methods. It begins by defining surface mining as extracting ore that lies near the surface by removing overburden. It then discusses the history of surface mining and factors to consider for evaluating surface deposits, including geography, legal issues, and economics. Specific surface mining methods covered include placer mining using panning, sluicing, hydraulicking, and dredging, as well as strip mining and open pit mining.
Opencast mining, also called open-pit or open-cut mining, involves removing mineral resources from the earth through large pits or holes dug on the surface. It has advantages like high coal extraction rates, mechanization, and fewer safety hazards than underground mining. However, it also causes issues like land degradation, deforestation, water and air pollution, and unpleasant sights from mining areas. Proper bench design, berms, haul road gradients, and safety measures are important for effective and safe opencast mining operations.
This document discusses underground coal mining methods and operations. It begins by describing different means of accessing underground coal seams, such as adits, shafts, and cross measure drifts. Factors to consider in selecting an access method include coal clearance, ventilation, topography, overburden depth, and costs. It then discusses development work, including driving main roadways and cut-throughs, and the equipment used like continuous miners and roof bolters. Pillars are left behind to support the mine openings, including barrier pillars to separate panels and chain pillars to control subsidence during longwall mining.
The document discusses various mining methods for steeply dipping and massive ore deposits. It describes caving methods like sublevel caving and induced block caving that are suitable for massive deposits with low ore value. It also outlines self-supported methods including sublevel stoping and large open stope mining. Supported methods such as cut-and-fill stoping and undercut-and-fill stoping are described as well. Each method is examined in terms of its applications, advantages, and disadvantages.
This document provides an overview of open pit mining technologies used in coal mines operated by SCCL in India. It discusses the key types of surface and subsurface mining methods. For open pit mining, it describes various mechanized methods used including shovel-dumper combinations, draglines, and bucket wheel excavators. It also outlines the ideal conditions for open pit mining and discusses operations involving stripping, drilling, blasting, extraction, and transport of coal. Pit design considerations like bench dimensions and slope angles are also summarized.
Open-pit mines are used when commercially useful minerals or rock deposits are near the surface and overburden is thin, as they are more economical than tunnel mining. Ore is extracted from successive vertical benches in the open pit until resources are depleted or overburden costs rise. Exhausted open pits are sometimes converted to landfills but may require water control to prevent flooding and formation of lakes.
This document discusses the Bord and Pillar method of coal mining. It involves leaving pillars of coal as support during initial mining, allowing for around 20% output. Later, the pillars can be extracted to increase output to 60%. The document focuses on the process of depillaring, or extracting the remaining coal from the pillars. This involves techniques like depillaring with stowing, where the emptied areas are filled with incombustible materials to control subsidence. Principles of safe pillar extraction are outlined, along with case studies and conclusions that depillaring must be done scientifically and safely according to regulations.
Open-pit mining involves digging huge portions of earth from the surface to extract desired minerals. The land face is scraped away through explosives and digging, creating a deeper pit until mining is complete. Open-pit mining has several levels of excavation displaying varying visuals as miners dig further. The process involves designing mining layouts, drilling, blasting, clearing blasts, digging, transporting ore, and cleaning up. While more efficient than underground mining, open-pit mining degrades the environment through destruction of habitat, dust, chemical pollution, and exposure of soil.
8.Monitoring process By Mr Allah Dad Khan Provincial Project Director CMP I...Mr.Allah Dad Khan
Monitoring is an important process to ensure quality and compliance. It involves regularly and closely observing a situation, system, or process to identify any issues or areas for improvement. Effective monitoring helps organizations achieve their goals and objectives on time and within budget by identifying and addressing problems early.
101 ideias criativas para grupos pequenoseraldo lima
Este documento fornece 101 ideias criativas para quebra-gelos, programas sociais e brincadeiras para grupos pequenos. Inclui dez mandamentos para dirigir atividades criativas e introduz várias ideias como noites temáticas, jogos, brincadeiras e atividades de grupo.
O documento discute o contexto histórico da obra Macunaíma de Mário de Andrade e como ela reflete as preocupações dos modernistas brasileiros da década de 1920 com a formação de uma identidade cultural nacional. Também analisa como certos aspectos da obra ainda ecoam problemas atuais relacionados à globalização e perda da identidade cultural frente a influências externas.
Este documento presenta el informe de prácticas preprofesionales realizadas en la Municipalidad Distrital de Huancan. El informe contiene cuatro capítulos que describen la institución anfitriona, los objetivos y actividades realizadas, los cuales incluyeron levantamientos topográficos y catastrales, así como la realización de calicatas. Finalmente, se presentan los resultados obtenidos y conclusiones.
Este documento describe los procedimientos para la perforación de núcleos de roca y muestreo de roca para investigaciones de sitio. Explica que la perforación diamantina profunda permite obtener muestras de roca y suelos a grandes profundidades para analizar las propiedades geotécnicas, geológicas y litológicas del subsuelo. Detalla los equipos necesarios como la sonda de perforación, bomba de agua, y brocas diamantinas, y explica cómo se usan estos equipos para perforar y rec
Los científicos colocaron cinco monos en una jaula con una escalera y plátanos. Cuando un mono subía, los otros eran rociados con agua fría. Luego, los monos golpeaban a cualquier mono que intentara subir, aunque ninguno había recibido agua. Cuando los monos fueron reemplazados, continuaron golpeando a los nuevos, a pesar de no conocer la razón original.
Nuclear fusion is the process by which lighter atomic nuclei fuse together to form heavier nuclei, releasing enormous amounts of energy. It is the process that powers stars like our Sun by fusing hydrogen into helium. Researchers are working to develop fusion as an energy source on Earth by containing and heating hydrogen isotopes to fuse in reactors such as tokamaks using magnetic and inertial confinement. Fusion reactors could provide safe, sustainable, and virtually limitless clean energy but developing viable commercial fusion power remains an engineering challenge that requires overcoming high costs and achieving breakeven where energy output exceeds energy input.
This document provides specifications for home construction by Executive Construction Homes. It details features like foundations, framing, insulation, roofing, windows, doors, appliances, plumbing, electrical, flooring, and allowances for items like appliances, lighting, hardware, cabinetry, tile, carpet and granite. Home designs and features are conceptual and subject to change based on the sales contract for the specific home.
The document discusses methods of underground coal mining using continuous miners. It describes how continuous miners are used in combination with shuttle cars to extract coal from underground seams through bord and pillar mining or pillar extraction methods. Bord and pillar mining involves driving headings into the coal seam to form pillars for extraction. Pillar extraction methods using continuous miners involve splitting or stripping pillars left from initial development. The document provides details on various pillar extraction techniques like pillar splitting, stripping, and split and fendering to remove remnant coal pillars. It notes the risks of roof falls and importance of experience when using these secondary extraction methods.
This chapter provides an overview of surface mining methods and equipment. Section 1 describes various surface mining methods including open pit mining, open cast mining, placer mining, and solution mining. Open pit and open cast mining use mechanical excavation in a dry environment, while placer and solution mining use water or chemical solutions. Section 2 briefly discusses large surface mining machinery such as bucket wheel excavators, shovels, and draglines. The chapter compares advantages and disadvantages of surface and underground mining, noting that surface mining typically has higher productivity and lower costs but can cause more environmental impacts.
The document provides information about training conducted at Tipong Colliery, an underground coal mine in Assam, India. It discusses the mine's location, history of operations since 1924 using various mining methods, geology of coal seams, current facilities, development plans, and manpower requirements. The mine extracts coal from the 60-foot and 20-foot seams using manual methods like pick mining and plans to mechanized development to reach deeper levels and extract more reserves.
03 azamat the experience of industrial processing of an uranium deposit of ak...Monatom Mgl
The document summarizes field experiments conducted at the Akdala uranium deposit in Kazakhstan, which uses in-situ leaching (ISL) methods. The objectives were to determine realistic production rates, optimize hydrodynamic processes without aquicludes, and monitor behavior of passing components. Testing of three blocks showed uranium concentrations exceeding 1 g/dm3. Commercial production began in 2006 and reached the designed capacity of 1000 tons of uranium per year, confirming experimental results. Distinctive features include high permeability, even mineralization distribution, and operation without complete aquicludes. The chosen development system and piping scheme ensured reliable rates for continued commercial operation.
Strip mining involves removing surface layers of soil and rock to access shallow mineral deposits. It is efficient for relatively flat, horizontal deposits close to the surface. Large machines like draglines, shovels, and bucket wheel excavators remove material in long, parallel strips, placing the overburden in the mined out areas. While low-cost and safe, strip mining significantly impacts the environment by destroying natural communities and can cause erosion and acid drainage into waterways. The economics depend on the stripping ratio of overburden to ore.
The document summarizes the challenges of drilling and blasting at the Helwan limestone quarry in Egypt. The quarry is located in a highly faulted geological area, which causes difficulties for drilling and blasting. A new urban community was also built near the quarry, requiring ground vibrations from blasting to be carefully controlled. Techniques applied to address these challenges included assessing fault locations using seismic studies, controlling drill parameters, measuring burden, and implementing deck blasting to optimize explosive charges for varying rock volumes. These steps helped improve drilling efficiency, blast safety, and rock fragmentation.
Isa mill technology_used_in_effecient_grinding_circuitsB P Ravi
The document discusses how IsaMill technology, which was originally developed for fine grinding, is now being used for coarser grinding applications due to its energy efficiency advantages over traditional grinding methods. Specifically, it can:
- Grind to sharp particle size distributions in an open circuit with a small footprint due to its ability to use fine media and avoid short-circuiting between its 8 grinding chambers.
- Use inert media like ceramic which avoids contaminating mineral surfaces during grinding, improving downstream flotation performance compared to steel media.
- Achieve higher energy intensities than other mills through its high-speed grinding discs, enabling grinding of coarser particles.
- Retain media without screens through its product separator design
The document discusses various methods of coal mining including surface mining techniques like strip mining and underground mining methods like bord and pillar and longwall mining. It outlines the history of coal mining and describes key steps in coal exploration. Factors that influence the selection of mining methods include the thickness and depth of coal seams, geology, roof and floor characteristics, and methane gas levels. The document concludes that coal forms from plant remains over geological time periods and that mining techniques have advanced with increased mechanization and automation.
This document summarizes various underground mining methods. It describes supported methods like cut and fill stoping which uses backfill, and unsupported methods like room and pillar mining where pillars provide natural support. It also discusses caving methods, including longwall mining where powered supports are used and sublevel caving where the ore and rock above cave in controlled columns. Conditions for each method are provided regarding ore and rock strength, deposit size and shape, depth, grade, and uniformity. The production cycle for each typically involves drilling, blasting, loading, and hauling, with auxiliary operations like ventilation and ground control.
This document provides an overview of shaft sinking methods for underground mining. It discusses traditional methods like wood/steel piling and open caisson as well as more advanced techniques like vertical shaft sinking machines (VSM) and shaft boring systems. The document highlights the advantages of mechanical excavation methods like VSMs in providing higher production rates and safety compared to traditional drill and blast operations. It analyzes case studies of shafts sunk in India and concludes that using advanced technologies could have increased production rates by 30% while improving safety and reducing costs compared to conventional shaft sinking methods.
The Evolution of Sublevel Caving at Trojan Mine, Bindura, Zimbabwe, J G TaylorJohn Guy Taylor
Several technical and economic factors have to be taken into
consideration in developing an optimal mining method. This paper
describes some of the important factors learnt during the evolution of the
sub-level cave mining method at Trojan Nickel Mine, part of the Bindura
Nickel Corporation (BNC) in Zimbabwe.
Highwall mining is a remotely controlled underground coal mining method that extracts coal from the face of a coal seam under a highwall in a surface mine. It allows for the economical extraction of coal reserves locked up in the highwall that would otherwise be unrecoverable. The process involves a continuous miner propelled by hydraulic push beams to cut the coal seam. Highwall mining provides a safer, more flexible and productive alternative to traditional underground mining for accessing thinner seams or areas with difficult geology. It has lower costs than underground mining due to requiring less infrastructure and supporting fewer personnel.
The document discusses the Nauseri area (C1) of the Neelum Jhelum Hydroelectric Project in Azad Jammu & Kashmir. It describes the geology and stratigraphy of the area which includes the Punajal and Murree formations separated by the Main Boundary Thrust fault. It outlines the composite dam and tunneling features in C1, including the use of drill and blast tunneling methods. Curtain grouting is also discussed as a method used to prevent seepage in the debris flow channel near the dam.
The document provides details about the Mumbai Coastal Road Project which includes construction of India's first undersea tunnel. Some key points:
1) A 2.07 km long twin tunnel is being constructed as part of the project, with 1 km being under the sea, making it unique from other tunnels worldwide.
2) India's largest Tunnel Boring Machine (TBM) named 'Mavala' has been deployed to excavate the tunnel and broke excavation records.
3) The tunnels will be 11 meters in diameter and constructed using concrete segmental lining for structural support and stability.
4) Numerical analysis of stress redistribution during various construction stages and the long-term condition will be conducted
This document provides details about the Kalia Bhomara Setu road bridge over the Brahmaputra River in Tezpur, Assam. It summarizes that the bridge connects NH 52 and NH 37 on the south bank via a 23km link. It describes some of the complex foundation work, including sinking 27 wells up to 56m deep, and constructing two well foundations with caissons up to 12m deep. The superstructure consists of balanced cantilever pre-stressed concrete box girders with 120m spans. Over 170,000 cubic meters of concrete and 12,000 metric tons of reinforcing steel were used.
A short description of Highwall Mining and its performance and application. The details of the equipments and the mining procedure are mentioned. Hope it will help you guys!
This document provides an introduction and overview of Dr. Andrew Cox's Coal Lectures Series. The series covers topics related to coal formation, properties, use as a fuel, mining technologies, markets, pollution control, and more. Dr. Cox and his colleagues at EIMR are available to provide lectures and teaching on these topics to universities and professional development courses both in the UK and internationally. Interested parties should contact Dr. Cox for more information. An introductory presentation on coal mining technologies is also included as an example of the type of material covered.
IRJET- Optimum Utilisation of Continuous Miner used for Pillar Extraction...IRJET Journal
This document discusses optimizing the use of continuous miners for pillar extraction in bord and pillar mining. It examines the performance of a continuous miner used in panel CMP-11A of an underground coal mine in India. The reliability of the continuous miner was found to be 89.87% with failures mainly due to issues with the gathering system, hydraulics, and conveyor. The document also describes the various roof support systems used in different conditions, such as at roadway intersections or areas with faults. Borehole data was collected and used to design support based on rock mass classification.
Valgma an evaluation_of_technological_overburden_thickness_limitIngo Valgma
This document discusses evaluating the technological limit of overburden thickness that can be removed by draglines in Estonian oil shale open cast mines. It presents the allowable stripping operation schemes for walking draglines currently used. A computer model methodology was developed to evaluate the technological limit of overburden thickness based on dragline geometry, mining conditions, and material properties. The results found the limit is 16-27m for dragline ES15/90 and 20-37m for dragline ES30/120, depending on geological and mining factors. Productivity calculations for the draglines are also presented, finding it decreases with more maintenance days and increasing overburden thickness.
IRJET- Assessment of Slope Stability in Opencast Coal Mines using SoftwareIRJET Journal
This document discusses using FLAC/Slope software to analyze slope stability in an open cast coal mine. It summarizes the software's ability to model different failure mechanisms and assess slope stability through numerical modeling. The study area contains three coal seams within barakar sandstone formations. Geo-mechanical testing of the lithologies was performed to obtain properties like density and shear strength for the slope stability analysis. Parametric studies show slope angle significantly impacts stability, with steeper angles reducing stability.
IRJET- Assessment of Slope Stability in Opencast Coal Mines using Software
3rd International Symposium6
1. 3rd
International
Symposium
May 6 - 8
2008
Zimbabwe holds at least 12% of world chromite resources, the majority
being hosted on the Great Dyke and mostly situated below present mining
depths. Zimasco’s chromite resources as at February 2007 were 107.5 Mt
of which 98% lies on the Great Dyke.
Zimbabwe’s contribution to the World market in 2007 was a chromite
output of 0.9Mt, of which 0.5Mt was produced by Zimasco. Chromite
production in Zimbabwe has not grown over the past decade as a result of
the costly and difficult nature of mining on the Great Dyke and because of
a controlled economy, which has stifled new investment.
This paper describes the current mining practice, previous mechanization
attempts on the Great Dyke and possible future mining methods.
Chromite
Seam mining
practice on
the Great
Dyke in
Zimbabwe
3. 3
3rd
International Symposium
On Narrow Vein & Reef Mining
May 6 – 8, 2008
CHROMITE SEAM MINING PRACTICE ON THE GREAT DYKE IN
ZIMBABWE
Walter Nemasasi,
Zimasco (Pvt) Ltd, 6th
Floor Pegasus House, Samora Machel Avenue, Harare, Zimbabwe.
ABSTRACT
The chromite resources of Zimbabwe are estimated at 900 million tonnes, the majority being hosted on
the Great Dyke. Most lie below present mining depths. Zimasco’s ore resources as at February 2007
were reported as 107.5Mt at 40.91% Cr203 and 2.12 Cr: Fe ratio. 98% of this resource (105 Mt) lies on
the Great Dyke and the remaining 2% is in podiform deposits off the Dyke in and around Shurugwi.
The Great Dyke is a linear NNE-trending body of mafic and ultramafic rocks, 550 km in length and
between 4 and 11km wide. It was formed 2460 million years ago by a series of separate magma
intrusions.
In the Mutorashanga area, 8 separate seams (seam numbers 4 to 11), averaging 12 cm in thickness are
known to exist. In the Ngezi and Lalapanzi areas the two main separate seams (seam numbers 1 and 2)
average 26 cm and 22 cm respectively. Dips in Mutorashanga vary from 26° to 38° and 11° to 18° in
Ngezi and Lalapanzi. (Fig. 1)
Chromite production in Zimbabwe has not grown over the past decade as a result of the costly and
difficult nature of mining on the Great Dyke and also because of the controlled Zimbabwean economy,
which has stifled new investment.
This paper describes the current mining practice on the Great Dyke particularly the resue variations in
the stoping method and the different mining layouts. A brief synopsis of previous attempts at
mechanisation using “Coal” cutting, Continuous mining, and Trackless mining techniques is also
presented, with some brief post mortems of why these trials did not survive the test of time. In
conclusion the paper offers possibilities for future mining methods that take cognisance of local
infrastructure.
5. 5
INTRODUCTION
Zimbabwe hosts 12% of world chromite resources and produced 4% (0.9Mt) of world production in
2007. (Figure2)
Fig. 2
In 2007 Zimasco (Pvt.) Ltd, produced 0.52Mt of the 0.9Mt of chromite produced by Zimbabwe. The
remainder came from Zimalloys, Maranatha, Oliken and a couple of other smaller producers. From a
reserve of 50Mt, figure 3 shows the distribution of extraction when compared with the reserve base.
Fig. 3
Strip mining on the dyke is carried out to 22 metres of vertical high wall in the Ngezi and Lalapanzi
areas which are amenable to this mining method because of the relatively flat terrain, with provisions
for a portal left every 500 metres on strike. These portals will in future be mined to 500 metres on dip
according to current designs. There is no strip mining in Mutorashanga because of the hilly terrain and
steep seam dips.
Initial exploitation of the seams in Mutorashanga is by aditing the resource in the hills down to the
lower ground level after which sub declines are sunk to exploit the deeper resources. Dyke
Underground mining then proceeds to 500 metres on dip. 80% of dyke underground mining is done in
Mutorashanga.
Surface mining is used to exploit podiform deposits at Valley and in Shurugwi to a depth of about 80
metres.
Underground podiform mining, which has been going on for more than a century in Shurugwi, has
been conducted using sub level open stoping.
6. 6
Chromite deposits on the Great Dyke have 2 distinct occurrences: -
A soft host rock (ucs 10 Mpa & hardness 4) containing friable chromite ore. This soft rock,
which can be drilled using auger machines, is predominant in Mutorashanga.
A silicified hard serpentinite (ucs 42Mpa & hardness 5) containing hard lumpy chromite ore.
This rock requires jackhammer drilling and is predominant on the rest of the dyke.
STOPING PRACTICE
The essential considerations in the extraction of chrome seams are the removal of the seam with
minimum fragmentation of the material and with minimum contamination by waste.
The method of exploitation almost universally employed is that of Resue Stoping on breast faces (for
dips ≤30º) and up-dip faces (for dips >30º).
The generally adopted technique is shown in Figure 4 below.
Fig. 4
Drilling and blasting the hanging wall waste down the full length of the stope face. The waste
derived from the blast is packed between timber props to fill the stope from footwall to hanging
wall (Figure 5). Excessive waste (30%) due to swell is lashed into the seam drive for tramming
to a waste pass and subsequent hoisting to surface for dumping. The stope floor is swept clean
before breaking the chrome.
The chrome seam exposed on the footwall is broken to induce separation and lifted with as
much care as possible to avoid fragmentation. (Figure 6)
Support consists of 2 rows of props close to the face, and back filling behind.
7. 7
Resue stoping on breast faces is in most cases practised on advance stoping with Retreat mining only
employed in areas where the ground is considered blocky and unstable. Up-dip stoping is seldom
applied where dips are less than 30º. In such cases, local faulting/jointing will be the determining
factor.
WASTE PACKING Fig. 5
8. 8
CHROME LIFTING Fig. 6
The shift cycle is explained in the table below.
Chrome lifting - Team Leader and 4 men 6 hours
Drill Charging and Blasting - Team Leader and 2 men 4 hours
Stope Waste Lashing - Team leader and 4 men 7 hours
Seam Drive Waste lashing - 2 men 5 hours
On an optimal panel length of 20 metres and an average of 19.8 metres advance per stope per month,
this translates to 26 centares per man per month.
9. 9
MINING LAYOUTS
ADITING
Artisinal miners drive adits on seam at 20m intervals on dip on the mountainside using auger drills
(Figure 7). The ore and waste swell is trammed to the mountainside for lowering using rudimentary
aerial ropeways and dumping respectively.
ADITS ON A MOUNTAINSIDE Fig.7
SHAFT ON SEAM (PILOT WINZE)
Incline shafts are sited on the outcrop at intervals of 500m and sunk on dip carrying the seam ±1m from
the footwall.
At 20m intervals seam drives are developed and a tramming loop mined in the hanging wall provides
short passes for storage of ore and waste.
These shafts (Figure 8) generally produce (±630t) from six stopes and carry two stopes as spare. They
are equipped with 70 hp hoists and mining progresses on dip to a maximum depth of 500m before the
shaft is re-sited. There are 16 such shafts operating in Mutorashanga, three in Ngezi and one in
Lalapanzi. Shaft output in each area is based on the parameters in the table below.
10. 10
Seam
Thickness
Stopes % Rec
Chrome
Seam Cont. SG Monthly
Tonnage
N/Dyke 0.12m 6 0.8 77% 3.6 632
M/Dyke 0.26m 6 0.8 90% 3.4 1512
S/Dyke 0.22m 6 0.8 90% 3.4 1280
PILOT WINZE Fig.8
Tramming in the drives is by hand, using 1.5t cocopans
The simple layout of an on-seam shaft is most common on the dyke because: -
Class 2 artisans can maintain the shaft.
The development off-reef is minimised, thus reducing negative exposure to blanks.
There is minimal mine planning and survey as day-to-day face advance direction is determined
by seam behaviour.
11. 11
INCLINED FOOTWALL SHAFTS
In cases where seam continuity has been good both on strike and on dip and plans concluded to increase
shaft output to +2000 tonnes, a footwall shaft has been mined below the pilot winze. (Refer to Fig. 9
below)
FOOTWALL SHAFT - 11 # LALAPANZI Fig. 9
The Pilot Winze now serves as the main return airway.
On every 5th
level, tramming crosscuts are developed into the footwall of the seam at 500m intervals
along strike. From there ore and waste passes are developed into the reef horizon.
The Footwall Shaft is mined on grade at initially ±15m below the pilot winze. The vertical distance
between the two shafts increases with depth as the Footwall Shaft is mined on grade and the Pilot
Winze follows the reef horizon whose dip flattens with depth.
The advantages of this layout are that: -
Activities on the reef horizon are separated from those in the shaft system
Hoisting for four sublevels is done from one main hoist station.
The disadvantage being: -
A high development rate per tonne ore
This exploitation method has been used extensively at 11 Shaft in Lalapanzi.
12. 12
PREVIOUS MECHANISATION ATTEMPTS
Several attempts at mechanisation using mainly coal-based technology have been made.
1960’s Vanad mine Coal Cutter Trials
1987 Joy Coal Cutter Studies
1990 – 1994 Roadheader ET110 plus Joy 14CM5 Continuous Miner
1994 – 1996 Vacuum Cleaning of stopes
1994 – 1999 Trackless mining - Skidsteer trials at Darwendale & Ngezi
2006 Stope productivity improvement.
Trials were made at Vanad Mine (AAC – Zimbabwe) in the 60s to win chromite using a coal cutter. In
1987, JOY concluded a study on using a 10RU universal coal cutter that “would eliminate ‘stopes’ and
therefore drastically reduce the moving of large quantities of rock..” Tests indicated that cutter wear in
chromite was going to be 18 times higher than in coal. The project was not implemented.
Between 1990 and 1994 a project promoted by the Government of Zimbabwe introduced an ET 110
Roadheader for mining declines and a JOY 14CM5 continuous miner for stoping. The project was
called off in April 1994 after 1342 meters of heading had been developed. Not much stoping was done.
High maintenance costs, low machine availability, ore dilution on the stope cutting and inability of the
machines to manage the steep dips negated against this project.
Trackless mining was introduced between 1994 and 1999 in Darwendale and Ngezi on declines mined
at an apparent dip of 10 degrees). Uniloaders/Skidsteers were introduced for underground mining. They
failed because of the steep dips, an abrasive ore which resulted in excessive tyre wear and a poorly
prepared environment for trackless mining. .
A study in conjunction with AEL Zimbabwe was conducted in 2006 to increase average stope advance
per month within current mining practice from 15 metres to 20 metres.
Three major constraints were identified in this study:
Stope lashing was taking +10 hours to complete and therefore a daily blast was not possible.
Because holes were marked at 80º to the face inclined towards the bottom drive, waste tended to
heave to the bottom of the stope requiring a lot of effort to use it to build the stope pack on the top
part of the stope. Furthermore, the muck pile had little throw resulting in the bulk of the broken
rock accumulating at the face to be cleaned rather than the back area.
+150mm rock in the muck pile was less than 50% of the broken rock. Miners were thus forced to
use smaller rock sizes for building the waste pack,which increased numbers of rock handled, and
therefore the time to complete the task.
Swell waste from the stopes was being lashed onto the footwall of the drive below before being re-
lashed into a cocopan.
These constraints were addressed by:
Increasing the stope lashing crew from 3 to 4, changing the direction of blast holes by 320º so that
the direction of muck throw was upwards in the stope, increasing the burden and spacing of the
holes from 0.4 metres and 0.75 metres to 0.5 metres and 0.8 metres respectively and carrying the
footwall of the reef drive 1.2 metres below the seam horizon to facilitate direct loading into
cocopans from the stope.
This initiative reduced stope-lashing time to 7 hours, allowed a daily blast and resulted in stope advance
increasing from 15 metres/month to 19.8 metres/month.
13. 13
FUTURE STOPING
Why does one need to change the current stoping method?
60 % of the stopes available in Mutorashanga are manned. Fewer people are prepared to do this
backbreaking work. This is an important consideration in future stoping methods.
The approach to stoping has been based on the assumption that waste packed in the back area plays an
important role in roof support. Geotechnical core logging has shown that ground competence improves
with depth. The upper portions (0-30 metres depth) have a rock classification ranging from 4A-3B.
Fracture frequency is higher than 10 and the rock is weathered. Below 30 metres, the rock classification
is 2B or better with fracture frequency per metre falling below 3 and the rock is not weathered.
Headings mined for the continuous miner, 3.2 metres width are still standing after 15 years. All this
evidence supports the current thinking that the packed waste does not provide active support and that if
all waste is hoisted out, timber and mechanical prop support will hold the roof.
Trials are now in progress to blast the seam in the centre of the panel in classical narrow reef breast
stoping at a stoping height of one metre. With no separation of reef and waste in the stopes, all material
is scraped into a box hole and hoisted to surface for segregation in a DMS plant. A history of stope
movement and costing will be built before roll out.
RESUE vs SCRAPER MINING Fig.10
14. 14
FOOTWALL DRIVE FOR SCRAPER MINING Fig. 11
Figure 11 and figure 14 depict the primary development layout alternatives under cosideration. The
layout as in figure 11 has been used at Hartley in Zimbabwe and is widely applied in the South African
platinum industry. Figure 14 is the traditional layout for track mining on the Dyke.
15. 15
FUTURE LAYOUTS
Layouts under design are being considered to take cognisance of future mining as follows: -
1. 2.5 times higher capacity shafts will be required for the same ore tonnage when all the waste is
hoisted to surface.
2. Where possible, shafts will be designed to cater for more than one seam.
3. Vertical shafts will be required to exploit the deeper sections of the dyke where the bulk of the
resource is. The syncline of these deposits varies from 100 metres in Lalapanzi to 1400 metres
in Mutorashanga. Mining depths in the same areas based on exploiting 500 metres on dip
A case study is presented which considers these options on a specific area in Mutorashanga.
16. 16
CASE STUDY 3-4 MILE SECTION AT ARTHUR’S LUCK
Description ofArea and Resource Estimate: -
The 3 - 4 Mile area is situated about 5km south of Mutorashanga. Seam numbers 5 to 9 are present
within Zimasco’s claims. Over a strike length of 3km and to a maximum depth of about 1.1 km the
mineable resource is estimated to be at least 2.3 million tonnes after leaving an 80m surface pillar,
which also takes into account any previous Artisinal mining.
Resource estimates are based on the following assumptions: -
Seam width 0.1m; Geological Factor 0.9; Recovery Factor 0.85 and SG of 3.5
The resource estimated for the individual seams are as follows:
Seam No. Strike Down Dip Tonnage
No.5 3000 175 140000
No.6 3000 450 360000
No.7 3000 550 440000
No.8 3000 750 600000
No.9 3000 975 780000
TOTAL PRODUCT 2320000
Three mining options are presented for the case study, these being: -
Option 1 – Incline Shaft
Option 2 – Vertical Shaft
Option 3 – Decline Ramps
At a mining rate of 1500t per seam,mining 4 seams,the life of mine is estimated to be 32 years.
The long sections for each of these options are shown in Figures 14 to 16 below.
20. 20
CONCLUSION
Zimasco’s podiform deposits will be mined out by 2015 and by 2020 the bulk of production will be
coming from dyke underground mining. The number of stopes will increase from the current 59 to 132
stopes (697 000ca).
Stoping in Mutorashanga is going to be dominated by scraper mining in the short to medium term, the
limiting factor on introducing low profile mechanised mining being the dip of the seams and the depth
of the syncline. Infrastructure will change to multiple seam serving decline or vertical shafts.
Trackless mining will be easier to introduce in the Ngezi and Lalapanzi areas with declines sunk at a
suitable apparent dip. Having two seams approximately 60 metres apart, this is a good area to put a
decline in between the seams.
The rate at which infrastructural upgrade and execution of these mining designs is going to be
implemented will depend on a good ferrochrome price outlook and a favourable country environment.
21. 21
ACKNOWLEDGEMENTS
The author would like to thank Zimasco (Private) Limited for permission to present this paper. The
author is grateful to George Blaver for providing 3D drawings of Lalapanzi and to various Zimasco
personnel, who helped in providing data, critiqued the ideas presented and helped assemble the paper.
REFERENCES
1. Butcher, D. W Dyke Mechanisation Programme
Unpublished, 1991
2. Ministry of Mines Chromium Mining
Publication No. 3
Government of Zimbabwe
3. Moore, D and Relvas, L Investigation Into The Possible Use Of
A Joy Universal Coal Cutter In A Zimbabwe
Chromite Deposit
October 1997
4. Szwedzicki, T and Bull, G A Report on Geotechnical Core Logging and
Rock Strength Testing
5. Takundwa, G and Mtemeri, M Underground Seam Productivity Improvement
Unpublished, 2006