keMi, Finl<strong>and</strong> Access to the underground operations. 68 underground mining methods
JelSˇ aVa, SlOVakia <strong>Mining</strong> magnesite at Jelšava Mechanization of overh<strong>and</strong> stoping in thick deposits As Slovakia moved from centralized control in the early 1990s, the management of Jelsava magnesite mine faced the accumulated problems of over-exploitation <strong>and</strong> under-mechanization. In the intervening years, the mining method has been revised, the equipment inventory renewed, <strong>and</strong> the output quality improved. Despite the sometimes difficult economic situation, accompanied by political upheavals, the employee-owned company SMZ that controls the mining operation is doing well. Atlas Copco <strong>and</strong> its local distributor ISOP have been there to lend a helping h<strong>and</strong>, as a result of which Rocket Boomer drill rigs <strong>and</strong> Simba longhole drill rigs have become Jelšava’s main production tools. Producing clinker The fully mechanized underground mine at Jelsava, operated by SMZ, feeds high grade magnesite to on-site conversion facilities with a capacity of 370,000 t/y raw clinker. The process includes primary <strong>and</strong> secondary crushing, followed by dense medium separation to produce a concentrate for thermal treatment in shaft <strong>and</strong> rotary kilns. Electromagnetic separators differentiate magnetic brickmaking clinker from non-magnetic steelmaking clinker. SMZ’s raw Jelšava clinker is converted to materials for metallurgical, ceramic <strong>and</strong> agricultural use. Annual production is around 352,000 t, comprising 167,000 t steelmaking clinker, 160,000 t of brickmaking clinker, <strong>and</strong> 25,000 t of basic monolithic refractory mixes. Overall, 85% of SMZ output is exported to 28 different countries. To contain production costs SMZ has been investing in more cost effective mining, <strong>and</strong> plans to replace the rotary kilns with more efficient twin-shaft kilns that emit very little dust. Map of Slovakia showing Jelsˇava location (Industrial Minerals). geology The Dúbrava-Miková orebody that SMZ exploits is the largest of 12 significant magnesite deposits in Slovakia. These extend from Podrecany in the west to Bankov, near Košice, in the east <strong>and</strong> were all mined for varying periods during the 20 th Century. The mineralization is part of a magnesite belt extending from cen- tral Austria to the Slovakia-Ukraine border. Within Slovakia, the deposits occur mainly in the Slovenské Rudohorie mountains, <strong>and</strong> Jelšava is in the deeply dissected Revűcka highl<strong>and</strong> area of this Rocket Boomer M2 C moving towards the faces. range. The magnesite deposit extends over 325 hectares within a spur of the Magura hill mass, <strong>and</strong> the maximum altitude of this spur is 675 m asl. The underground mine is accessed laterally from portals in the sides of the spur, <strong>and</strong> mineral moves through the process plant downhill from the primary crusher, which is outside the mine on the same level as the main haulage. The magnesite is part of a sedimentary sequence that has been subjected to tectonic forces <strong>and</strong> metamorphism, especially during the Variscan <strong>and</strong> Al- pine events. This sequence, underlain by underground mining methods 69
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Mining Methods in Underground Minin
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Contents Foreword 2 Foreword by Han
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Mining TrendS Trends in underground
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Rock production (2005) Ore (Mt) noi
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geOlOgy FOr Mining geology for unde
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Sandstone. Gneiss. Many salts, for
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drives within the mineral deposit,
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Mineral prospecting and exploration
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Atlas Copco underground core drilli
- Page 19 and 20: Finding the right balance in explor
- Page 21 and 22: % 100 80 60 40 20 0 Canada latin am
- Page 23 and 24: Mine inFraSTruCTure underground min
- Page 25 and 26: pumphouses and workshops. Drill/bla
- Page 27 and 28: Principles of raise boring efficien
- Page 29 and 30: Typical operating installation of t
- Page 31 and 32: MeCHanized BOlTing Mechanized bolti
- Page 33 and 34: on the latest Boomer and Simba seri
- Page 35 and 36: Mining in steep orebodies Based on
- Page 37 and 38: main level, providing access and ve
- Page 39 and 40: waste ratio during a typical muckin
- Page 41 and 42: Mining in flat orebodies nearly hor
- Page 43 and 44: crosscut drift Foot wall (The Fossu
- Page 45 and 46: BaCkFilling Backfilling for safety
- Page 47 and 48: Thickener Binder cement and/or slag
- Page 49 and 50: History Mining has been conducted a
- Page 51 and 52: 0.1% Cu, 99 g/t Ag and 0.3 g/t Au.
- Page 53 and 54: This joint development process star
- Page 55 and 56: zinkgruVan, Sweden Changing systems
- Page 57 and 58: longhole open stoping has contribut
- Page 59 and 60: flexibility during drilling and bol
- Page 61 and 62: increasing outputs at lkaB iron ore
- Page 63 and 64: 2 Groups of ore passes 7 Developmen
- Page 65 and 66: keMi, Finland From surface to under
- Page 67 and 68: The crusher station at the 560 m le
- Page 69: Kemi is carrying out slot hole dril
- Page 73 and 74: Pillar between stopes 5.0 m-high, b
- Page 75 and 76: kure, Turkey all change for asikoy
- Page 77 and 78: m along the footwall contact, or in
- Page 79 and 80: History The El Soldado and Los Bron
- Page 81 and 82: Max 15.0 m Ventilation shaft 17 to
- Page 83 and 84: Simba M6 C drilling radial holes. a
- Page 85 and 86: Pioneering mass caving at el Tenien
- Page 87 and 88: caving in primary rock. Currently,
- Page 89 and 90: Production area 5 4 80 m 57,5 m 22,
- Page 91 and 92: used is again panel caving with pre
- Page 93 and 94: introduction Codelco, renowned for
- Page 95 and 96: During pilot hole drilling and rea-
- Page 97 and 98: 40 m in length were drilled each mo
- Page 99 and 100: anTOFagaSTa, CHile Modernization at
- Page 101 and 102: MOunT iSa, auSTralia Mount isa mine
- Page 103 and 104: 4500N Advance south Stoping sequenc
- Page 105 and 106: to the hanging wall. The fill used
- Page 107 and 108: MelBOurne, auSTralia High speed hau
- Page 109 and 110: The Minetruck MT5010 exits from the
- Page 111 and 112: geology The Olympic Dam mineral dep
- Page 113 and 114: Activity Overview Mucking Overview
- Page 115 and 116: on site. Later stopes, which are no
- Page 117 and 118: improved results at Meishan iron or
- Page 119 and 120: ig, six hours/shift, two shifts/day
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Mechanized mining in low headroom a
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large scale copper mining adapted t
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tricky, because the pillars in the
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gerMany/SOuTH kOrea underground min
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which are spread over 10-130 Mpa. A
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CaMPO FOrMOSO, Brazil Sub level cav
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Slot drilling at Ferbasa: The Simba
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getting the best for Peñoles Speci
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They went from drilling 20 m downwa
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keeping a low profile at Panasqueir
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Boomer S1 L drill rig in operation.
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