OverView of THEORIES OF ROCK BOLTING
Theories of Rock Bolting 0 CommentIn coal mining, the surrounding strata is weakened and fractured around mine openings in underground mines due to the in situ stress redistribution. The main purpose of rockbolt reinforcement is to improve the internal load bearing strength of the rock mass to support itself (Bieniawski, 1984). Rockbolt performance is influenced by the […]
Read MoreFIBRE GLASS
Types of Bolts 0 CommentFibre Glass (FG) Dowels / Fibre – Reinforced Polymer (FRP) FG and FRP dowels are made by pultrusion, a process that combines extrusion and pulling of molten or curable resin and continuous fibres usually arranged in unidirectional layers, through a die of a desired structural shape (“pull” and “extrusion”). FG […]
Read MoreCABLE-TYPES & SIZES
Types of Bolts 0 CommentCable bolt application in mining For several decades now, cable bolting systems have been used for ground stabilisation and reinforcement in mines. There are around 19 types of cable bolts used in Australian mines, classified into main five categories. These are; (a) smooth or plain surface cable bolt; b) Bulbed; […]
Read MoreBOLTING TECHNOLOGY
Overview 0 CommentHOW ROCK BOLTS ARE MADE Most solid rock bolts are manufactured by producing a deformed bar in a hot rolling mill. These deformed bars have deformations or ribs which run around the circumference of the bar, and they provide an interlock and load transfer mechanism with the resin or grout […]
Read MoreHISTORY OF ROCK BOLTING
Overview 0 CommentRock bolting is one of the most efficient supporting devices ever developed. The earliest case of using bolts as a rock reinforcement method was in a slate quarry in North Wales in 1872 (Schach et al., 1979). In 1918 a coal mine in Germany introduced bolts as a means of ground […]
Read MoreOVERVIEW
Ventilation 0 CommentCoal mine ventilation systems must be designed so as to maintain at all times healthy and safe atmospheric working conditions. The main purposes of a coal mine ventilation system are to provide adequate quantities of fresh air to the miners in the workings and to render harmless toxic, noxious, and […]
Read MoreGROUND CONTROL
Ground Control 0 CommentAs bord and pillar workings are developed roof support becomes a major consideration and operating cost item. Support requirements vary considerably and are dependent on the physical conditions in the seam, which are often depth dependent, and the length of time that the workings are required to be serviceable. The […]
Read MoreEXTENDIBLE CONVEYOR
Equipment 0 CommentzIt is obvious that shuttle car conveyance is a batch, discontinuous process which reduces the overall production rates achievable from a continuous miner as a result of the inter car wheeling delays. Extendable or flexible conveyor systems reaching from the tail end of the panel conveyor to the continuous miner […]
Read MoreBREAKER LINE SUPPORT (BLS)
Equipment 0 CommentThe BLS were originally pioneered in the RSA at Middlebult Colliery by Voest-Alpine commencing in 1984 and later trialled in several Australian collieries commencing in 1987. Their subsequent use in pillar extraction panels has become widespread with some 60 units in operation by 1991. A BLS units is illustrated to […]
Read MoreBOLTER
Equipment 0 CommentTechnical specifications of Pneumatic and Hydraulic roof bolting rigs ALMINCOGopher CRAM Wombat FIREFLY INTFire Fly HYDROMATICARO-4000 SIGHBM 50 ALMINCOBeaver Mode of power Pneumatic Pneumatic Pneumatic Hydraulic Hydraulic Hydraulic Range (m):smallest (3 Stge)largest (3 Stge) 0.771 – 1.2271.374 – 3.657 0.442 – 0.7591.347 – 3.539 1365 – 32531145 – 2793 […]
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