Underground Mining Definitions PDF

MINE 201 UNDERGROUND MINING CHAPTER 1 INTRODUCTION& DEFINITIONS  Types of Mineral Deposits Massive: A deposit of considerable lateral and vertical extent in which mineralization (or ore) is relatively uniformly distributed. Ex: Disseminated Copper ores like Sudbury Basin (Dome salt is...

MINE 201 UNDERGROUND MINING CHAPTER 1 INTRODUCTION& DEFINITIONS  Types of Mineral Deposits Massive: A deposit of considerable lateral and vertical extent in which mineralization (or ore) is relatively uniformly distributed. Ex: Disseminated Copper ores like Sudbury Basin (Dome salt is also included in this classification) Bedded or Tabular: A mineral deposit that parallels the stratification, most often in sedimentary rock, usually laterally extensive, and of limited thickness. Ex: Coal seams and evaporate mineral deposits (e.g. potash) fall in this class. 1-2  Types of Mineral Deposits Narrow Vein: A zone or belt of mineralization (ore) typically long, narrow (less than 3m), often dipping steeply, and usually lying within boundaries separating it from neighboring rock. Ex: Many gold, silver and other metallic minerals such as mercury antimony occur in narrow veins. Wide Vein: As defined under narrow vein except that the vein thickness is greater than 3 m. 1-3  Types of Mineral Deposits Lenticular or Pocket: An isolated ore body, or an enrichment of limited vertical and horizontal extent in a massive bedded or vein deposit. Ex: Lead, zinc and iron ores often occur in this shape. Placer: A surface or near surface deposit, usually tabular and may be of considerable areal extent, containing mineral particles (e.g. gold, platinum) in detritus (e.g. Zn, sand, gravel) 1-4  DEFINITION OF TERMS A) General Terms Mining is the process of obtaining useful minerals from the earth’s crust and includes both underground excavations and surface workings. Prospecting is searching for ore. Exploration is the work involved in gaining a knowledge of the size, shape, position and value of an ore body. Development is the work of driving openings to and in a proved ore body to prepare it for mining and transporting the ore. Exploitation is the work of mining and marketing the ore. 1-5  quest on l feofm n answer.s Quest on d scover stage prospect ng search ng forore explorat on ga n ng nfoabout ore 0 s ze shape value pos t on deta led feas b l ty study answer development k v ndaOPEYIpo.PE Eetorm n explo tat on work of m n ng andmarket ng the ore  DEFINITION OF TERMS B) Deposit and Spatial Terms Back is the roof of overhead (overlying) surface of an underground excavation. Bottom is the floor or underlying surface of an underground excavation. Capping waste material (barren rock) overlying the mineral deposit. Country Rock The rock (waste material) in which the ore deposit is enclosed. capp ng barren rock extract ng at the same t me w th country rock Crown Pillar Portion of the deposit overlying an excavation and left in place as a pillar. d p d pd rect on str ke Dip is the angle of inclination of a deposit (bed, stratum or vein), measured from the horizontal (also pitch or attitude). Floor is the bottom or underlying surface of an underground excavation. 1-6 d p d pd rec str ke y.esI E s ne compassd rect on of the outcrop ore the longerd mens on n planv ew of a ve n on a hor zontal surface IEangle. n degress between a hor zontal plane and the ncl ned ve n measure down from n hor aplane zontal to the str ke perpend cular Pn Üü d pd rect on perpend cular tothestr ke d pd rect on str ke 90 T shape symbol d p d rect on 1-12 surface püf m ned Ü ons floor Kloof top overly ng surface blur TEN underly ng 1-10  1 support element s llp llar Yn backf lled 111111111 explo tat on produce F nd g open ngs IYI r bp llar quest on p llar outcrop answer  YYYY s llp llar m backf lled 1-9  DEFINITION OF TERMS B) Deposit and Spatial Terms (cont’d) Footwall is the wall rock under the deposit. Hanging Wall is the wall rock above a deposit. Gob is the broken, caved, and mined out portion of the deposit. Ore is a mineral deposit that can be worked at a profit under existing economic conditions. Outcrop is the surface exposure of a mineral deposit. Pillar is the unmined portion of the deposit, providing support to the roof or hanging wall. Prospect is a mineral deposit, the value of which has not been proved by exploration Rib is the side wall of an excavation (also rib pillar). Roof is the back, top or overlying surface of an excavation. 1-7  DEFINITION OF TERMS B) Deposit and Spatial Terms (cont’d) Sill Pillar is the unmined portion of the deposit underlying an excavation and leftt in place as a pillar Strike is the main horizontal course (or direction or bearing) of a mineral deposit Wall Rock is the country rock adjacent to a deposit. Waste is the barren rock or the rock of too low a grade to be mined economically. Gangue is the worthless minerals associated with the valuable minerals in an ore. 1-8 argue kulüp capp ng barrenrock same t me t raf.tnnyatrocthe He gangue s valuable than waste Günün 1-11  DEFINITION OF TERMS C) Directional Terms Breast: Advancing in a near- horizontal direction; also the working face of an opening. Inby: Toward the working face, away from the mine entrance. Outby: Away from the working face, toward the entrance. Overhand: Advancing in an upward direction Underhand: Advancing in an downward direction. 1-13  DEFINITION OF TERMS D) Excavation Terms Adit is a horizontal or nearly horizontal passage (or opening) driven from the surface (a single access to the surface ) (compare to tunnel) 1-14  DEFINITION OF TERMS D) Excavation Terms Bell (Cone) is a funnel shaped excavation formed at the top of a raise to move bulk material by gravity from a stope to a drawpoint. Cone Caving 1-15  DEFINITION OF TERMS D) Excavation Terms Bleeder: Exhaust ventilation lateral 1-16 Bleeder  DEFINITION OF TERMS D) Excavation Terms (cont’d) Chute is a loading arrangement that utilizes gravity flow to load a conveyance or to move bulk material from a higher level to a lower level. Crosscut is a horizontal or nearly horizontal u/g opening that is driven to intersect (perpendicular to the strike) an ore body often connects drifts, entries or rooms. Decline is an inclined opening that is driven downward (or underhand) to connect levels (Also declined shaft) Drawpoint is the loading point beneath a stope, utilizing gravity to move bulk material. Downward and into a conveyance, by a chute or loading machine (also boxhole). Drift is a horizontal or nearly horizontal u/g opening, oriented Parallel to the strike of a dipping orebody. Entry: Multiple (two or more) underground openings leading to a deposit (coal). 1-17 E 1-18  DEFINITION OF TERMS D) Excavation Terms (cont’d) Finger Raise: Vertical of near vertical opening(s) used to transfer bulk material from a stope to a drawpoint (usually branch together to the same delivery point). Grizzly is coarse screening or scalping device that prevents oversized bulk material from entering a material transfer system; constructed of rails, bars, beams etc. Haulageway is a horizontal opening used primarily for materials handling (transportation). Incline is an inclined opening that is driven upward (or overhead) to connect levels (also inclined shaft) Lateral is a horizontal opening; often parallel (or at an angle) to a haulageway, usually to provide ventilation or some auxiliary service. Level is a system of horizontal u/g openings connected to a shaft; comprises an operating horizon of a mine. 1-19 Grizzly 1-20  DEFINITION OF TERMS D) Excavation Terms (cont’d) Loading Pocket is the transfer point at a shaft where bulk material is loaded by bin, hopper, and chute into a skip. asansör Longwall is horizontal or inclined exploitation opening in tabular deposits with several ten’s or hundred’s meters of length. Manway is compartment of a raise or an inclined opening intended for personnel travel between two levels. Orepass is a vertical or inclined u/g opening though which ore flows by gravity. Portal is the mouth (or connection) of an adit or tunnel to the surface. Raise is a vertical or inclined opening u/g opening that is driven upward from one level to a higher level or to the surface. Ramp is an inclined opening driven in a downward direction to connect levels; allows the passage of motorized vehicles. 1-21 Room is horizontal exploitation opening in a bedded deposit.  Longwall Loading Pocket Manway 1-22 Ore Pass Ramp – Ore Pass 1-23 RAMP ORE 1-24 Portal 1-25  DEFINITION OF TERMS D) Excavation Terms (cont’d) Shaft is the primary vertical (or near vertical) opening connecting the surface with underground openings (vertical shaft); if it connects two levels u/g, it is called blind shaft. Slope is an inclined opening (also inclined shaft) connecting the surface with u/g workings. Slot is narrow, vertical or inclined opening excavated at the end of a stope to provide a bench (or free) face towards which the blasting can be made. Stope is a large exploitation opening, (i.e. The place where the ore is produced). It may be vertical, inclined or horizontal. Sublevel is secondary or intermediate level between main levels or horizons. Sump is an excavation made u/g to collect water, from which water is pumped to another sump at a higher level or dirctly to the surface. Usually placed at the bottom of a shaft, near the shaft on a level, etc. 1-26 Epump  DEFINITION OF TERMS D) Excavation Terms (cont’d) Transfer point is the location in the materials handling system, either haulage or hoisting, where bulk material is transferred between conveyances. Tunnel is a horizontal or nearly horizontal opening with access to the surface at both ends. Undercut is a low horizontal openings excavated under a stope to induce breakage and caving of the deposit (A kerf cut in the face is different). Winze is a vertical or inclined opening that is driven downward (or sunk) from one level inside a mine to another level below for the purpose of connection or exploration. 1-27 1-23 Transfer Point 1-29 Figure 1 Typical arrangement of mine development 1-30 Figure 2 Exploration of an ore prospect by 1-31 surface and underground core drilling  STAGES IN THE LIFE OF A MINE 1) Prospecting 2) Exploration 3) Detailed Feasibility Study Preliminary mine planning (or final) 4) Development Final Design 5) Exploitation The resulting feasibility report is primarily an economic one, but legal, technological, geologic, environmental, and sociopolitical aspects are also included. The key recommendation of a feasibility study is either To proceed with work or To delay the work or To terminate further work 1-32  STAGES IN THE LIFE OF A MINE Realism is imperative and a high degree of expertise and wisdom is required for preparing the feasibility report In case of realistic and positive report preliminary mine design proceeds the feasibility study. With the help of the additional data obtained during development, the final design of the mine can be done. 1-33  THE CONTENTS OF A FEASIBILITY REPORT 1. Preface: Summary, definitions 2. General: Location, climate, topography, history, ownership, land status, transportation, etc. 3. Environmental Concerns: Present conditions, standards, necessary protective measures, land reclamation, special studies, etc. 4. Geologic factors: Deposit setting, origin, structure, mineralogy, petrography 5. Mineral Reserves: Exploration procedure, findings, calculation of tonnage and grade of reserves, extent and grade of by products (if any). 6. Mining Plan: Development and exploitation. 7. Processing: On-site facilities needed. 1-34  THE CONTENTS OF A FEASIBILITY REPORT 8. Surface (and u/g) Plant: Location, construction plan. 9. Auxiliary and Support Facilities: Power, water supply, road access, waste disposal, housing, etc. 10. Staffing: Work force (labor and supervisory) 11. Marketing: Economic survey of supply and demand price, long term contracts, substitutes, etc. 12. Costs: Estimation of direct, indirect and overall costs of development and exploitation, costs of processing, transportation, smelting, etc. 13. Economic Valuation: Valuation of deposit, classified as to type reserve or resource, calculation of present worth. 14. Profit Projection: Determination of profit margin based on range of cut off grades, prices. 1-35  DEVELOPMENT It involves all the necessary steps to bring a mine into full, scheduled production. For this purpose, the u/g mine needs a system of excavations in the rock to gain access to the mineralized areas and to open up the deposit for exploitation. Prior to the start of the exploitation phase of mining development is limited in so far as possible to the construction of primary or main openings. Main openings describe the general layout for the mine. 1-36 GENERAL LAYOUT FOR UNDERGROUND METAL MINES The objectives: Opening up the deposit from the surface – Shafts – Inclines or Declines – Ramps – Adits (for hillside deposit) Layout and allocation of other development works – Horizons – Sub levels The final layout of mine always be a result of very complex studies on the economic, technical and rock mechanical circumstances given by the deposit. 1-37 GENERAL LAYOUT FOR UNDERGROUND METAL MINES o Economic Considerations: Outside access, surface rights, labor and living conditions, power supply, water rights, means of transportation, government restrictions, royalties and taxes. o Technical Considerations: Terrain: Space availability, topography, climate, vulnerability to natural disasters, etc. Environmental: Air, water, soil and waste pollution, reclamation, subsidence, public relations, etc. Geologic: Size, shape, dip and depth of the deposit, rock types, deposit structure (folds, faults, etc.), alteration, weathering, etc. o Rock Mechanical Considerations State of stress, rock strength, hardness, abrasiveness, modulus of deformation, swelling or squeezing rocks, etc. 1-38