Mining SystemHENDRA HARISMAN, ST., M.ENG.SC.

26 FEBRUARI 2015

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Mining operations – life stages• Prospecting

– discovery of mineral deposit

• Exploration

– ore body definition – size, shape, geometry, ore, waste, etc.

• Development

– mineral rights acquisition, environmental impact statement, construction of access roads, surface facilities, access to ore body

Mining operations – life stages• Exploitation

– excavate ore body

– surface or underground mining methods/systems

• Reclamation and closure

– site restoration

Mining system selection• Spatial characteristics of the deposit

– Size – height, thickness, and other dimensions– Shape – tabular, lenticular, massive, or irregular– Attitude – dip, strike– Depth, mean and extreme values– Ore boundaries– Existence of previous mining

Mining system selection• Spatial characteristics of the deposit

– Surface vs. underground– Mine layout– Materials handling– Production rate

Mining system selection• Geologic and hydrologic conditions

– Mineralogy and petrology – sulphides vs. oxides in copper– Chemical composition – primary and secondary minerals– Deposit structure – folds, faults, etc.– Planes of weakness – joints, fractures, shear zones– Uniformity of grade– Existence of strata gases

Mining system selection• Geologic and hydrologic conditions

– Selective and non-selective mining methods– Ground support requirements– Pumping and drainage requirements– Mineral processing and smelting requirements

Mining system selection• Geotechnical properties

– Ore and rock strength– State of stress (pre-mining, post-mining)– Rock mass rating– Other physical properties – specific gravity, voids, porosity,

permeability, moisture content

Mining system selection• Geotechnical properties

– Equipment selection– Support requirements

Mining system selection• Economic considerations

– Reserves (grade and tonnage)– Production rate (tonnes per day/month/year)– Mine life– Productivity– Capital and operating costs

Mining system selection• Economic considerations

– Output– Investment– Cash flow– Payback period– Profit

Mining system selection• Technological factors

– Recovery – proportion of ore extracted– Dilution– Flexibility to changing conditions– Selectivity between ore and waste– Mechanization– Capital and labour requirements

Mining system selection• Technological factors

– Choice among possible methods– Subsequent operations – processing, smelting, environment

Mining system selection• Environmental concerns

– Waste disposal– Workforce– Safety– Atmospheric control – ventilation, air quality, heat and humidity– Subsidence or caving effects– Post-mining use

Mining system selection• Procedure

– Engineering judgement – some factors are not quantifiable– Quantified evaluations

- computerized operations research based methods

Mining system selection• Conceptual study – physical characteristics and production

potential of mining methods and layouts are assessed• Engineering study – quantified parameters are compared• Detailed design study – drawings and construction specifications

for preferred method are prepared• Flexibilities and variations in the preferred methods must be

considered at this stage– Possible new technologies

Mining system• Surface mining systems • Underground mining systems

Surface mining systems• Open pit mining

– Metallic and non-metallic ores– Mass production

• Open cast/strip mining– Coal

• Quarrying– Dimension stones – marble, granite

• Solution mining

Underground mining systems• Unsupported mining systems

– Room and pillar mining– Stope and pillar mining– Shrinkage stoping– Sublevel stoping

Underground mining systems• Supported systems

– Cut-and-fill stoping– Stull stoping– Square-set stoping

Underground mining systems• Caving systems

– Long-wall mining– Sublevel caving– Block caving