From drilling machines to excavators, crushing and grinding equipment the mining. Underground mining techniques and risks geology for investors. Its wise for an investor to understand both the basic workings for an underground mine and the risks associated with underground mining. The primary objective of underground mining is to extract ore safely and economically while minimizing handling of waste rock. Types of underground mining method comparison shrinkage stoping. It is not an exact science and in the choice of a method each varying factor has a certain weight, which, in many cases, experience alone can.
New technology has enabled greater productivity and safer mining in underground operations, which has also helped decrease the cost of such production methods. Types of drilling methods used in mining boring mining. The rest of the coal is left in place in the form of pillars that hold up the roof and prevent. It is not an exact science and in the choice of a method each varying factor has a certain weight, which, in many cases, experience alone can determine.
In underground coal mining, the working environment is completely enclosed by the geologic medium, which consists of the coal seam and the overlying and underlying strata. Underground mines are more expensive and often used to reach deposits that are deeper. However, the first step is to loosen the rock in the ore body so that it can be moved and processed. The grades or quality of the orebody are high enough to cover costs. The general practice of the field is to sink vertical shafts, generally on the footwall side, free from the liability of disturbance from settlement due to stoping. In australia, the majority of coal mining is done via the opencast method, although often the method of choice is dependent on certain characteristics of the coal deposit 1. Highgrade ores of metals, like gold, iron, silver, and copper. In contrast soft rock mining refers to excavation of softer minerals such as coal, or oil sands. In fact, it can extract almost 90% of ore from a deposit. Jul 24, 2016 types of underground mining and their applications. The earlier method of mining was done by human beings who dug the earths surface deep into the earth to form an underground passage and excavate the mineral resources.
Longwall mining is a highly mechaniz ed underground mining sys tem for mining coal. In this method which is the oldest one of drilling, the hole is drilled by striking a number at short in intervals on the rock. The mining rate is greater than 20,000 tonnes per day tpd but is usually much greater. The choice of an underground mining method depends on a range of factors and these include. In both mining techniques, the mined ore must be removed from the mine and transported to a plant for processing and refining. The methods of mining followed in this field, and even in individual mines, are varied in accordance with the character of the ore. As with other types of hard rock mining there are several methods of extraction. South africa has the worlds deepest hard rock gold mine up to 3,900 metres 12,800 ft underground. Once exposed, the ore in the pit is broken up by blasting. In any discussion of methods of underground mining comparison, one is repeatedly confronted with the difficulty of dealing with so many variable conditions. Diamonds are mined from kimberlite through three types of diamond mining. Underground hard rock mining refers to various underground mining techniques used to excavate hard minerals, usually those containing metals such as ore containing gold, silver, iron, copper, zinc, nickel, tin and lead, but also involves using the same techniques for excavating ores of gems such as diamonds or rubies. In this selective mining method, the void created by mining is backfilled with a mixture of waste rock or tailings with cement sometimes added to strengthen the mixture, which helps support the walls of the empty space.
Pwc open pit mining mining methods 5 open pit mines are used to exploit low grade, shallow ore bodies. Classification of underground mining methods mineral production in which all extracting operations are conducted beneath the ground surface is termed underground mining. They used to carry the materials manually to reach the surface. Underground mining is the process of extracting minerals and ores that are located too far underground to be mined efficiently using surface mining methods. These surface mining methods are considered to be more efficient and economical in extracting minerals as compared to most methods of underground mining. Mining types and methods centers for disease control and. Shrinkage stoping refers to any overhand method in which. In this article we will discuss about the types of drilling methods used in mining. Underground mining is more complex and more expensive than openpit mining. Types of underground mining and their applications youtube. These deposits usually occur beneath barriers like a rock layer, forests, or oceans, which makes accessing them difficult. Mining types and methods coal mining hardrock mining metal mining nonmetal mining oil and gas extraction sand and gravel mining stone mining surface mining benching. Surface and underground coal mining are broad activities that incorporate numerous variations in equipment and methods, and the choice of which method to use in extracting a coal seam depends on many technological, economic.
In comparison to other methods, underground mines impact less on the environment and are much more harmful to those working within them. Mining method selection by multiple criteria decision making tools by m. Mining techniques can be divided into two common excavation types. Selective mining methods cut and fill mining is a method of shorthole mining used in steeply dipping or irregular ore zones. Used a lot by south african gold mining companies, this method can be used in both soft and hard rocks as the working area along the mining face can be supported. For example, the ore extracted from the australian olympic dam mine has a concentration of 0. Jul 21, 2016 underground mining is the process of extracting minerals and ores that are located too far underground to be mined efficiently using surface mining methods. Underground mining hard rock underground hard rock mining refers to various underground mining techniques used to excavate hard minerals such as those containing metals like gold, copper, zinc, nickel and lead or gems such as diamonds.
Often, surface mining is preferred over underground mining, or subsurface mining, for numerous reasons. For this reason, surface mining is the most widely used method in north america. Underground mining is used for deposits at greater depth, higher grade deposits, or vein ores. The methods used in the mining of gem materials are many, from native mining to highly technical methods. Once the ore is broken, excavators load the ore into. Shrinkage stoping is a shorthole mining method which is suitable for steeply dipping. Breast stoping refers to the working of a flat orebody. Both types of ore deposit, placer or lode, are mined by both surface and underground methods. Depending on the mining method, a working section can have one or more working faces. There are five basic types of surface mining, including openpit mining, strip mining, dredging, mountaintop removal, and highwall mining. A brief introduction to the types of surface mining methods. Today, surface mining is much more common, and produces, for example, 85% of minerals excluding petroleum and natural gas in the united states, including 98% of metallic ores.
Jan 27, 2014 undergrounds mining is still, even after hundreds of years of safety improvements, a dangerous and expensive business. Types of underground mining and their applications. In surface mining, the rock barrier on top of the deposit is removed to access the ore. Counting against underground mining are the costs, which, for each ton of material mined, are much higher underground than on the. In combination, these factors allow us to determine an appropriate arrangement and sequence for. All methods of surface mining will remove the waste material, or overburden, above the desired resource. Later mechanical methods were used to bring the materials and the amount of extraction also increased. Placer mining is used to sift out valuable metals from sediments in river channels, beach sands, or other environments. Underground mining is more expensive, but less environmentally destructive. Depending on the mineral being mined and the nature of the deposit, there are many different underground mining methods that can be implemented. The panels are the working sections of the production operation. Sometimes openpit mining is used, such as at the fort knox mine in central alaska. Access to the coal seam is gained by suitable openings from the surface, and a network of roadways driven in the seam then facilitates the installation of service facilities. Underground mining has a lower ground footprint than open pit mining.
Underground mines are more expensive and are often used to reach deeper deposits. Openpit mining involves removing the layers of sand and rock found just above the kimberlite. Kimberlite is commonly found in kimberlite pipesvertical structures in the earths crust. Deposits with steep dips angle with horizontal, and good stability. Block caving is essentially the underground version of openpit mining. When it comes to mining coal, there are two processes by which coal can be removed from the ground. Underground mining methods are usually employed when the depth of the deposit andor the waste to ore ratio stripping ratio are. Openpit is one of the most common mining methods used and starts from the earths surface, maintaining exposure to the.
Mining method selection by multiple criteria decision. When any ore body lies a considerable distance below the surface, the amount of waste that has to be removed in order to uncover the ore through surface mining becomes prohibitive, and underground techniques must be considered. The underground mining methods we use include room and pillar, narrow vein stoping and largescale mechanised. Sciencestruck explains what these methods are, with the applications of each one. What are two main types of mining and how do they differ. Surface mines are typically used for more shallow and less valuable deposits. Gemstone mining open cast mining pit mining terrace mining underground mining tunneling block caving chambering water bodies river diggings dry diggings wet diggings sea tidal undersea or marine mining open cast mining. The reason they differ, is because underground mining is where they create shafts that lead to. Underground mining methods and applications production headframe hans hamrin 1.
A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Other gold mines use underground mining, where the ore is extracted through tunnels or shafts. In contrast, underground mining requires the creation of two parallel and vertically connected tunnels where miners in the top tunnel blast the ore of the kimberlite pipes which falls and collects on the bottom tunnel. Barrick gold corporation has one of the largest openpit gold mines in north america located on its goldstrike mine property in northeastern nevada. The method involves undermining an ore body, then allowing it to collapse under its own weight. Mining then follows the vein of ore and the underground mine develops. Ataei synopsis mining method selection is the first and most important problem in mine design. These are the methods techniques employed when the depth of the deposit,the stripping ratio of the overburden to ore,or both becomes excessive to surface exploitation. The two main types of mining are surface mining and underground mining.
Typically, underground mine has less environmental impact. Drift and fill is similar to cut and fill, except that it is used in ore zones. Learn vocabulary, terms, and more with flashcards, games, and other study tools. An underground mine consists of the portals entrance and exits to the mines, mains, submains, panels, and working faces.
This is an extreme of combination stoping in which the working face. Depending on how these ores are extracted, mining methods can be categorized as surface or underground types. All of these methods remove the waste material or the overburden, that is above the desired resource. Some mining, including much of the rare earth elements and uranium mining, is done by lesscommon methods, such as insitu leaching. Surface mining involves stripping surface vegetation, dirt, bedrock and other layers of the earth to reach. Mining is further divided into several other categories including room and pillar mining, slope mining, block caving, quarrying, openpit mining and in situ mining. The most common types of mining equipment vary depending whether the work is being carried out above or below ground or mining for gold, metals, coal or crude oil. Underground coal mining methods and engineering dust controls. The ore body is too deep to mine profitably by open pit. In case of uranium mining, it strongly depends on the concentration of uranium in the ore. There are two types of pipe mining, namely openpit mining and underground mining. After openpit mining is complete, valuable ore can be mined through underground mining methods.
The third method, marine diamond mining, extracts diamonds from the ocean floor. It is defined as a concentration of minerals that can be exploited and turned into a saleable product to generate a financially acceptable profit under existing economic conditions. Mineral exploitation in which all the extraction is carried out beneath the surface of earth. Here are the types of underground mining and their. The various methods of mining a coal seam can be classified under two headings, surface mining and underground mining. The method to be used for underground mining depends on the concentration of ore, strength of the surrounding rock, and the various risks involved. Surface mining is often preferred to subsurface underground mining by mining companies for several reasons. It set of longwall mining equipment consists of a coal shear er mounted on convey or operating. Types of underground mining underground mining for coal is conducted by either room and pillar mining or longwall mining. Underground or subsurface mining involves the digging of a network of shafts and tunnels into the earth to reach and extract the deposit of ore or mineral beneath the earth.
Underground mining methods while most mineral deposits can be mined by either surface or underground methods, some minerals can only be recovered in a hybrid manner, usually by initial extracted by open pit mining, followed by underground methods. Where removing the overburden would be too costly or ineffective to reach the ore, the decision is made to go underground. Hardrock mining techniquesunderground minesminings method. A highly productive underground mining method, longwall mining is used in a large horizontal spread of thinbedded deposits of uniform thickness usually ranging from 0. At such depths, the heat is unbearable for humans, and air conditioning is required for the safety of the workers. The first step in selecting the most appropriate mining method is to compare the economic efficiency of extraction of the deposit by surface and underground mining methods. In this selection some of the parameters such as geological and geotechnical properties, economic parameters and geographical factors are involved.