9781439834220.ch13

9 120 32r 12 180 52r 15 90 61r 18 240 71r 21

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Unformatted text preview: -cone blasthole bits Drill rods Stabilizers and reaming heads are some of the drilling accessories © 2005 by Taylor & Francis Group, LLC Usual range 23R (0.9, 120), 32R (1.2, 180), 52R (1.5, 90), 61R (1.8, 240), 71R (2.1, 460), 72R (2.1, 240), 82R (2.4, 300), 85R (3.7, 300) and 121R (3.7, 910). 100 to 400 0–117 r.p.m 116,000 to 2000,000 N-m 4.1 t to 112 t Hydraulic except in two models 0.9 to 3.7 m 90 m to 910 m 225 to 375 mm dia. i.e. 9 to 15 in. dia. 8–10 in. dia. and 4–5 length EXCAVATIONS IN UPWARD DIRECTION – RAISING 349 different models of raise borers have been designed and built to suit the needs of many different applications. Based on past experience the models developed by Robbins Co; the range of some of the specification7 have been summarized in table 13.1. Table 13.23 displays working range of some of the Atlas Copco/Robins very recent (2002) models. In table 13.3 field data of some 17 raises bored by borers in different rock types have been presented. To site an example of its use in mines, LKAB Iron Ore Mines, Sweden some 16.5 km of sinking and raising have been done.3,4 This mine has been divided into eight production areas, each containing its own group of ore passes and ventilation systems. At this mine a total of 32 ore passes between the 775 and 1045 m levels were driven using Tamrock and Robbins raise borers and rest of the task has been by some other companies. This technique offers several advantages such as: ● ● Safety – Man is not required to enter into the raise during its drivage. Stability – Circular raise configuration is stable and allows smooth flow of air. The raise sides are obtained without impact of drilling and blasting. Even in weaker Table 13.2 Some of latest raise borer models by Atlas Copco/Robins with their working ranges.3 Model Nominal diameter, m Diameter range, m Nominal length, m Maximum length, m 34 H 43 RM 53 RE/RH 73 RM 83 RM 97 RL 123 RM 1.2 1.2 1.5 2.4 4.0 4.0 5.0 0.6–1.8 1.0–1.8 1.2–2.4 1.8–3.1 2.4–5.0 2.4–5.0 3.1–6.0 340 250 490 550 500 600 920 610 610 650 700 1010 1010 1100 Table 13.3 Performance of raise borers in different rock-types, diameter and length. Raise dia., ft Length, ft Inclination degrees Advance rate ft/hr r.p.m. Purpose Rock type 4 4 4 5 5 5 5 6 6 6 7 7 7* 7* 9 12 12 511 879 1677 289 391 776 1078 447 938 1114 764 750 1140 1200 145 440 678 90 90 90 90 89 85 90 78 90 90 90 90 90 90 90 90 90 2.2 17.7 11.3 1.3 7.4 3.1 6.8 4.4 1.3 2.3 1.6 1.5 11 4.9 3.3 2.7 3.6 14 32 32 18 14 15 22 18 14 22 18 18 10 10 7 8 8 Quartzite Sandstone, siltstone Limestone Quartzite Limestone Sulfide, rhyolite Limestone, dolomite Diopside, quartz Diorite, gneiss Graywacke Gabbro, diorite Quartz, Quartzite Limestone Shale, sandstone Limestone, dolomite Shale, sandstone Shale, sandstone Shaft pilot Ventilation Ventilation Ore pass Ventilation Waste pass Ventilation Ore pass Shaft pilot Ventilation Ventilation Pilot vent Ventilation Ventilation Ventilation Ventilation Ventilation * Using Robbins Raise Bor...
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This document was uploaded on 02/12/2014.

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