Mining-exam.docx

**Ore:** Ore is **natural rock or sediment that contains one or more valuable minerals, typically containing metals**, that can be mined, treated and sold at a profit. **Ore deposit:** Is an accumulation of ore which can also be referred to as an occurrence of a particular ore type. **Gangue**: Th...

**Ore:** Ore is **natural rock or sediment that contains one or more valuable minerals, typically containing metals**, that can be mined, treated and sold at a profit. **Ore deposit:** Is an accumulation of ore which can also be referred to as an occurrence of a particular ore type. **Gangue**: The valueless mineral particles within an ore deposit that must be discarded. It is a particular type of waste. **Waste**: Materials associated with an ore deposit that must be mined to get at the ore and must be discarded. **Prospecting:** Search for ore or geologic occurrences that have a potential of being an ore body. **Exploration:** Activities of evaluating a geologic prospect to determine its size, shape, grade, and profit potential. - Analyze samples from drilling or excavation, assay, test. - Estimate tonnages and grade - Valuate deposit -hoskold formula or discount method - Present value = income --cost **Prospecting methods:** - Direct: Physical geologic (limited to outcrops) - Indirect: Geophysical, geochemical (hidden deposit) Locate favorable loci (using maps, literature, old mines) Air: aerial photography, airborne satellite images Surface: ground geophysics, geology Spot anomaly, analyze, evaluate **Exploration methods** - Remote sensing (satellite imagery); Aerial remote sensing - Geological mapping; Planning starts with regional and local maps, followed by new map showing vegetation and location of rock types. - Geochemical sampling: Locating a particular mineral deposit by chemical analysis of rocks, stream sediment soils, water, gas or vegetation. - Geophysical surveys: Collecting information about the physical properties of a mineral deposit on the ground or from the air (remote sensing). - Geochemical surveys; and - Bulk sampling and drilling: Drilling to define the size of the orebody - If the mining company decides to develop a mine, a mining licence is required. **Feasibility study** to find a decision to abandon or develop. The FS considers economic, political, social and environmental aspects. **Pre-feasibility study** in which mining and processing methods are established and sufficient to determine if resources can be classified as reserves; and **Exploration life cycle:** 1\. Available land resources, prospecting and early, Intermediate exploration, Advanced exploration, mineral development, restoration and reclamation. **Mine life cycle:** Prospecting/exploration: searching sampling and analysis to ore reserve and generate feasibility report Development: Planning logistics for mining operation + building the mine Extraction: extracting the ore Closure: remediation or redevelopment of the land to more natural state. **Type of metal:** **Classification of surface mining** Base metal: Iron lead zinc Precious metal is rare and high economic value: gold silver Ore grade: Concentration of economic mineral or metal in an ore deposit. **Mineral resource** A mineral resource is a mineral deposit that is potentially valuable, and for which reasonable prospects exist for eventual economic extraction. Categories: inferred, Indicated, Measured mineral resource **Mineral resource estimation** is the process of estimating the tonnage, grade, size, shape, and location of mineral deposits. **Mineral reserve** Is the portion of a measured or indicated mineral resource that is economically mineable at a given moment in time. Category: Probable, proven ore reserve. The ore reserve estimate follows the resource estimate, and generally require sat least a prefeasibility study to establish quantity and grade of a mineral that may be profitably and legally extracted from the deposit. Mineral resource valuation implies the assigning of a currency value to the worth of a mineral deposit. As such **determining the value of the mineral property**. When choosing between surface and underground methods, some of the factors that must be considered include Size, shape, and depth of the deposit Geologic structure Productivities and machinery capacities Availability of experienced work force Capital requirements and operating costs Ore recoveries and revenues Safety and injuries Environmental impacts, during and after mining **SURFACE MINING** An excavation or cut made at a surface for the purpose of extracting ore and which is open to the surface for the duration of the mine's life. Examples of surface Mining Methods: Open pit Mining Strip Mining Quarrying **UNDERGROUNDMINING** When do we mine underground? The ore deposit is deep. Grade is high enough to exceed costs. Access to an underground mine is made through shafts and/or ramps. SUSTAINABLE DEVELOPMENT **meets the needs of the present without compromising the needs of future generations**. Sustainable mining is when we conduct essential resource extraction while improving social, economic and environmental outcomes. **Classification of Mines** Masses moved \[ t or m3\], Run of Mine Production \[ t or m3\], Production of usable content (metal content)\[ t \], Investment ( total, specific) \[€, Number of employees (pit/mine/company/contractor), Importance for regional/national economy Environmental impact **Systematic of Open Pits** **methods pose the risk of water contamination, deforestation, erosion, increase vulnaribility** - ground or strata failure. - inundation or inrush of any substance. - mine shafts and winding operations. - roads or other vehicle operating areas. - air quality or dust or other airborne contaminants. - fire or explosion. - gas outbursts. - spontaneous combustion. The simplest method of land reclamation involves simply **filling the area with large amounts of heavy rock and/or cement, then filling with clay and soil until the desired height is reached**. Drilling of longholes from the sublevels\ Drilling of fans using drill rigs\ Relatively small hole diameter (50-75 mm Rotatory, down hill