Coal Lectures Series Mining Technology

This document discusses continuous miners, an underground coal mining technology. Some key points: 1) Continuous miners use a mass production method and can be used for room and pillar and shortwall mining. Their use has increased production at some CIL mines in India to over 0.5 Mte annually. 2) Ideal conditions for continuous miners include seam thickness of 1.8-5m, gradients less than 1 in 8, and hard, dry floor conditions. Several CIL mines have been identified to introduce the technology. 3) The technology involves a continuous miner cutting coal which is loaded onto shuttle cars and transported to a feeder breaker. Roof bolting then occurs before the min

Methane (CH4) is commonly known as firedamp in coal mines. There are three primary reasons for giving special attention to methane: 1) it is the gas most commonly found in underground coal mines, 2) it has caused more explosions and loss of life than any other cause in mining history, and 3) continued development of methane drainage technology. Methane is formed during the coalification process from decaying organic material and becomes trapped within coal seams. When coal is mined, methane can be released through gradual exudation, gas blowers, or violent outbursts. Due to its light weight, methane also has a tendency to form layers near mine ceilings, which can become explosive if ignition occurs.

Room and Pillar mining method is one of the oldest existing mining methods. This system in which the mined material is extracted across a horizontal plane, creating horizontal arrays of rooms and pillars. Usually those room and pillars are uniform size. Pillars may or may not be removed after extraction. Used for soft as well as hard rock mining and is commonly associated with coal, potash, uranium, and other industrial materials.

Underground mining is used to access ores and minerals located far beneath the ground when surface mining is not economical. It involves digging tunnels into the earth to extract resources. There are two main types - hard rock mining which extracts metals and gems, and soft rock mining which extracts materials like coal. Access tunnels or shafts are dug and levels are excavated horizontally to reach the ore body. Machinery is used to continue mining and remove material, while supports are installed to prevent cave-ins. Proper ventilation is needed to remove gases and regulate air flow and temperature. Underground mining can be more environmentally friendly than surface mining but is also more hazardous due to safety issues like gas exposure.

This document discusses roof support in underground coal mines. There are two main types of roof support: intrinsic supports like roof bolts that are installed within the roof, and standing supports like timber props that are installed between the roof and floor. Timber supports are commonly used in Indian coal mines due to low cost and availability, though metal supports offer higher load capacity. A case study examines how roof bolts were used with a specific layout and spacing in the Tandshi coal mine in India. Proper roof support is necessary to prevent roof collapse and protect miners from rock falls.

The document discusses the Longwall Top Coal Caving (LTCC) method for underground mining of thick coal seams. LTCC uses a longwall setup and natural forces to aid in coal extraction. It addresses problems with traditional thick seam mining like coal loss and support costs. The document outlines the LTCC process, stress distribution during caving, and enhancements like using vibrators. Key advantages of LTCC are high resource recovery, reduced costs, improved productivity and safety. The conclusion states that LTCC can significantly increase production if site conditions allow for the method.

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.

The document discusses mining methods and equipment used for underground coal mining using the bord and pillar method. It provides specifications for various mining equipment used including Load Haul Dumpers (LHDs), Side Discharge Loaders (SDLs), drilling machines, conveyors, haulage systems, and their capacities. Formulas are given to calculate production rates based on machine specifications and operating parameters.

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.

Drilling is the process of making holes into hard surfaces like rock. In surface mining, drilling is used for blast hole drilling, core drilling for exploration, and technical drilling. Rotary blast hole drilling involves rotating drill pipes to which a bit is attached to break up rock. The main assemblies of a rotary drill rig include the mast, rod changer, rotary head, pull down mechanism, air compressor, drill pipes, hydraulic system, and dust control components.

Underground mining methods include room-and-pillar, longwall mining, sublevel caving and block caving. Longwall mining involves completely removing the entire coal seam in one operation by leaving no pillars and allowing the roof to cave. Factors that influence the selection of an underground mining method include the deposit's size, shape, depth and geology, geotechnical properties, economic considerations, available technology, and environmental concerns. The optimal mining method maximizes resource recovery while maintaining safety and minimizing costs and environmental impacts.

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.

Placer Deposits; PLACER MINING; Hydraulicking mining; Dredging mining; Types of Excavation Methods Using Dredging; BUCKET WHEEL HYDRAULIC DREDGES; BUCKETLINE DREDGES; SUCTION CUTTER DREDGES; PLACER MINING COSTS

There are five main types of mine support systems: (1) Wooden logs support which is cheap but cannot be reused and requires coating to prevent corrosion. (2) Metal rod support which is reusable but expensive and prone to corrosion. (3) Metal roof bolts provide strong ceiling support but are expensive. (4) Metal fence support provides warning of collapse while also collecting falling rocks but is also expensive. (5) Concrete and brick walls provide excellent support for soft, clayey rocks but are difficult to modify and remove once installed. Proper support systems are crucial to mine safety, production continuity, and equipment protection.

rock excavation, different open cast or open pit excavation machinery, application, limitations, highwall miner, bucket wheel excavatorr, bucket chain excavator, shovels