Mining Information

Overburden

noreply@blogger.com (Unknown) — Sun, 30 May 2010 02:21:00 +0000

Overburden is the material that lies above the area of economic or scientific interest (in mining and archaeology) e.g., the rock, soil and ecosystem that lies above the coal seam or ore body. It is also known as 'waste'. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally finely milled ore. Overburden is removed during surface mining, but is typically not contaminated with toxic components and may be used to restore an exhausted mining site to a semblance of its appearance before mining began. Overburden may also be used as a term to describe all soil and ancillary material above the bedrock horizon in a given area.

A related term is interburden, meaning material that lies between two areas of economic interest, such as the material separating coal seams within strata.

By analogy, overburden is also used to describe the soil and other material that lies above a specific geologic feature, such as a buried astrobleme.

From http://en.wikipedia.org/

Ore sorting

noreply@blogger.com (Unknown) — Mon, 26 Apr 2010 14:44:00 +0000

Ore sorting refers to the process of separating an ore into separate constituent parts. Today, ore sorters are widely used in industrial mineral mines, diamond mines and base and precious metal mines.

Ores are typically sorted to increase the efficiency of other refining processes, by reducing the amount of material to be processed while simultaneously increasing its purity.

Modern technologies

Modern, automated sorting applies optical sensors (visible spectrum, near infrared, X-ray, ultraviolet), that can be coupled with electrical conductivity and magnetic susceptibility sensors, to control the mechanical separation of ore into two or more categories.

Commonly sorted ores

* Base and Precious Metals
o Gold
o PGMs
o Copper
o Zinc
o Nickel
* Industrial Minerals
o Pegmatites
o Limestone
o Calcite
o Dolomite
o Coal
o Magnesite
o Quartz
o Feldspar
* Gems
o Diamonds
o Tanzanite

Reasons for industrial sorting

* Pre-concentrate mill feed into high-grade and low-grade fractions
o Build a smaller mill or effectively increase the capacity of an existing mill
o Remove low-grade fraction that is actually costing money to mill
o Add previously uneconomic zones to reserves
o Manage ore blending programs more effectively
* Sort high-grade ore out of low-grade stockpiles and waste dumps
o Recover value from previously uneconomic waste
* Reduce environmental risks and costs
o Reduce mill energy consumption
o Send acid generating waste rock to appropriately designed dumps
* Optimize multiple process streams
o Send appropriate ore directly to the mill, leach heaps or smelter
* Pre-concentrate ore underground or at remote sites
o Reduce haulage and hoisting costs
o Mine satellite orebodies and sort on site
* Monitor the composition of the mill feed
o Provide real time data to operators for process optimization and work index prediction

From http://en.wikipedia.org/

Ore concentrate

noreply@blogger.com (Unknown) — Fri, 23 Apr 2010 13:56:00 +0000

Ore concentrate text

Ore concentrate, dressed ore or simply concentrate is the product generally produced by metal ore mines. The raw ore is usually ground finely in various comminution operations and tailings(waste) are removed thus concentrating the metal component. The concentrate is then transported to smelters where it is used to produce useful metals.

From http://en.wikipedia.org/

Optical granulometry

noreply@blogger.com (Unknown) — Wed, 21 Apr 2010 03:21:00 +0000

Optical granulometry is the process of measuring the different grain sizes in a granular material, based on a photograph. Technology has been created to analyze a photograph and create statistics based on what the picture portrays. This information is vital in maintaining machinery in various trades worldwide. Mining companies can use optical granulometry to analyze inactive or moving rock to quantify the size of these fragments. Forestry companies can zero in on wood chip sizes without stopping the production process, and minimize sizing errors.

With more photoanalysis technologies being produced, mining companies have shown an increased interest in these types of systems because of their ability to maintain efficiency throughout the mining process. Companies are saving millions of dollars annually because of this new technology, and are cutting back on maintenance costs on equipment.

In order for optical granulometry to be completely successful, an accurate photo must be taken – under sufficient lighting, and using proper technology – to obtain quantified results. If these requirements are met, an image analysis system can be implemented.

From http://en.wikipedia.org/

Oil shale industry

noreply@blogger.com (Unknown) — Sat, 17 Apr 2010 03:27:00 +0000

Oil shale industry is an industry of mining and processing of oil shale—a fine-grained sedimentary rock, containing significant amounts of kerogen (a solid mixture of organic chemical compounds), from which liquid hydrocarbons can be manufactured. The industry has developed in Brazil, China, Estonia and to some extent in Germany, Israel and Russia. Several other countries are currently conducting research on their oil shale reserves and production methods to improve efficiency and recovery. However, Australia has halted their pilot projects due to environmental concerns. Estonia accounts for about 70 % of the world's oil shale production.

Oil shale has been used for industrial purposes since the early 1600s, when it was mined for its minerals. Since the late 1800s, shale oil has also been used for its oil content and as a low grade fuel for power generation. However, barring countries having significant oil shale deposits, its use for power generation is not particularly widespread. Similarly, oil shale is a source for production of synthetic crude oil and it is seen as a solution towards increasing domestic production of oil in countries that are reliant on imports.

From http://en.wikipedia.org/

NAICS 21

noreply@blogger.com (Unknown) — Sat, 10 Apr 2010 19:13:00 +0000

NAICS 21 is the category within the North American Industry Classification System which is composed of establishments that extract naturally occurring mineral solids(i.e. as metals, coal and other industrial minerals), liquid minerals (i.e. crude petroleum) and gases (i.e. natural gas).

Definition of mining

NAICS 21 uses the term "mining" to include quarrying, well operations, beneficiating and other mineral preparation customarily performed at the mine sites, or as a part of mining activity and distinguishes two basic activities:

Mine operation

Mine operation includes companies that operate mines, quarries, or oil and gas wells for themselves, and companies which operate them on a contract or fee basis.

Mining support activities

Mining support activities include companies that perform exploration (except geophysical surveying) and other mining services, on a contract or fee basis, with the exception of mine site preparation and construction of oil/gas pipelines.

Further breakdown

Companies are grouped and classified according to the natural resource which is or will be mined. Industries include establishments that develop the mine site, extract the natural resources, and/or those that process the mineral mined.

Smelting and refining

Smelting and refining take place in both the "mineral processing" (NAICS 21) stages and the manufacturing stages (NACIS 31-31).

From http://en.wikipedia.org/

Mineral industry

noreply@blogger.com (Unknown) — Wed, 07 Apr 2010 01:15:00 +0000

Mineral industry is the branch of industry responsible for the exploitation of minerals from soil deposits. This is achieved by mining (through underground excavations or open workings), but also by processing plants. Products of mineral industry include various building materials, such as rocks (ex. granite), but also cement, glass and ceramics.

Worldwide

* Mineral industry of Africa
* Mineral industry of Asia
* Mineral industry of Europe
* Mineral industry of North America
* Mineral industry of South America
o Mineral industry of Colombia

From http://en.wikipedia.org/

Miner's helmet

noreply@blogger.com (Unknown) — Sun, 04 Apr 2010 11:06:00 +0000

A Miner's helmet is a type of helmet worn for safety purposes by miners while in the process of mining.

From http://en.wikipedia.org/

Mine Caps

noreply@blogger.com (Unknown) — Tue, 30 Mar 2010 15:11:00 +0000

Mine Caps are typically used to prevent access to old, abandoned mines. People, especially the young, like to explore their surroundings but may not fully understand the dangers inherent within, and surrounding, a mine.

Why Do Mines Need To Be Capped?

Cave-ins, poor air quality, wet slippery surfaces, etc. are real dangers when entering a mine, but even the surrounding area can be dangerous. Older mines may have been covered with logs or wooden beams with loose rock and soil over the top. These fail over time, creating sinkholes, that may not be visible on the surface, until enough weight collapses it.

Law Requirements

Federal and State laws dictate certain aspects in the capping process, such as allowances for bats to have access. The type of mine, water table, geology, etc. are all considered when choosing which type of cap will be used for a given mine entrance.

Concrete Caps

Concrete continues to be the preferred method for capping vertical shafts. Considerations can be made in the design to allow for an entrance to the mine, a steel door for humans, a slot for bats, a hole for airflow. The slabs thickness can vary from as little as 6 inches to several feet.

Expanding Foam

Expanding foam is quickly replacing concrete for some vertical shafts, typically mines where an entrance for humans is no longer desired. This type of cap is sometimes referred to as a "Plug." Plugs usually have a taper to them, smaller on the bottom and wider on the top, like the cork on a wine bottle. Expanding foam plugs need to be quite thick, usually no less than 6 feet deep. Typically, loose rock and soil is placed over the top.

Steel Plates

1/4 inch or thicker steel-plating is also used, on both horizontal and vertical shafts. These allow for easier customization than concrete, cutting access holes in steel is far easier than building the concrete forms necessary for the same result. This type of cap is used where easy access is a necessity.

From http://en.wikipedia.org/

Magnetation (iron ore)

noreply@blogger.com (Unknown) — Tue, 23 Mar 2010 01:31:00 +0000

Magnetation is a term referring to the processing of iron ore tailings, the waste product of iron ore mines, to recover hematite. Crushed mine tailings are mixed with water to create a slurry; the slurry is then pumped through magnetic separation chambers to extract hematite. Commercial interest in this process stems from the possibility of extracting additional iron from tailings supplied by existing mines, increasing their yield.

From http://en.wikipedia.org/

Fly-in fly-out

noreply@blogger.com (Unknown) — Wed, 17 Mar 2010 06:03:00 +0000

Fly-in fly-out is a method of employing people in remote areas.

Overview

Rather than relocating the employee and their family to a town near the work site, the employee is flown to the work site where they work for a number of days and are then flown back to their home town for a number of days of rest.

Fly-in fly-out is very commonly used in the mining industry, as mines are often in areas far from towns.

Usually a fly-in fly-out job involves working a long shift (e.g. 12 hours each day) for a number of continuous days with all days off spent at home rather than at the work site. As the employee's work days are almost entirely taken up by working, sleeping and eating, there is little need for any recreation facilities at the work site. However, companies are increasingly offering facilities such as pools, tennis courts and gyms as a way of attracting and retaining skilled staff.

Generally fly-in fly-out work sites use portable buildings as typically there is no long-term commitment to the work site (e.g. the mine will close once the minerals have been extracted).

Employees like fly-in fly-out arrangements as their families are often reluctant to relocate to small towns in remote areas, due to the lack of opportunities for partner's employment, limited educational choices for children and poor recreational facilities.

Employers prefer fly-in fly-out arrangements when the cost of establishing facilities of sufficient quality to attract families to live locally will exceed the cost of creating basic facilities for a fly-in fly-out community plus the cost of airfares.

Negative effects

On the negative side, fly-in fly-out employment can put stress on family relationships and may stifle regional development.

Mining towns that once had a considerable size, like Wiluna in Western Australia, which had a population of 9,000 in 1938, have shrunk to a population of 300, with almost all employees of the local mines on fly-in fly-out rosters.

From http://en.wikipedia.org/

Face (mining)

noreply@blogger.com (Unknown) — Sat, 13 Mar 2010 17:21:00 +0000

In mining, the face is the surface where the mining work is advancing. In surface mining it is commonly called pit face, in underground mining a common term is mine face.

Accordingly, face equipment is the mining equipment used immediately at the mine face used for removal and near-face transportation of the material: cutting machines, loaders, etc.

From http://en.wikipedia.org/

Exploration diamond drilling

noreply@blogger.com (Unknown) — Mon, 08 Mar 2010 15:39:00 +0000

Exploration diamond drilling is used in the mining industry to probe the contents of known ore deposits and potential sites. By withdrawing a small diameter core of rock from the orebody, geologists can analyze the core by chemical assay and conduct petrologic and mineralogic studies of the rock.

History

Early diamond drilling opened up many new areas for mineral mining, and was related to a boom in mineral exploration in remote locations. Before the invention of the portable diamond drill, most mineral prospecting was limited to finding outcrops at the surface and hand digging.

Diamond drilling

Exploration diamond drilling differs from other geological drilling (see Drilling rig) in that a solid core is extracted from depth, for examination on the surface. The key technology of the diamond drill is the actual diamond bit itself. It is composed of industrial diamonds set into a soft metallic matrix. As shown in the figure, the diamonds are scattered throughout the matrix, and the action relies on the matrix to slowly wear during the drilling, so as to expose more diamonds. The bit is mounted onto a drill stem, which is connected to a rotary drill. Water is injected into the drill pipe, so as to wash out the rock cuttings produced by the bit. An actual diamond bit is a complex affair, usually designed for a specific rock type, with many channels for washing.

The drill uses a diamond encrusted drill bit (pictured on the right) to drill through the rock. The drill produces a "core" which is photographed and split longitudinally. Half of the split core is assayed while the other half is permanently stored for future use and reassaying if necessary. Although a larger diameter core is the most preferred it is the most expensive. The most common diameter sizes of core are NQ and CHD 76.

Core extraction

Merely advancing the drill by rotary action (and washing) causes a core to be extracted inside the barrel as shown. However, at a depth of perhaps 300 m, there must be a way to retrieve the core and take it to the surface. Constantly withdrawing the entire heavy drill pipe is impractical, so methods were developed to pull up the core inside the barrel. If the rock would always be solid granite, and the core would always break at the drill bit, then it would be a simple matter to stop the drilling, and lower a simple grabbing device by a wire and pull up the core. Unfortunately, many applications require an undisturbed core in fractured rock, which calls for elaborate wire-line devices.

The photo shows the extraction of a core, using a triple-tube wire-line system, capable of extracting core under the worst conditions. This is very important when exploring fault zones such as the San Andreas Fault.

Tube sizes

There are five major "wire line" tube sizes typically used. Larger tubes produced larger diameter rock cores and require more drill power to drive them. The choice of tube size is a trade-off between the rock core diameter desired and the depth that can be drilled with a particular drilling rig motor.

From http://en.wikipedia.org/

Core sample

noreply@blogger.com (Unknown) — Sun, 28 Feb 2010 00:01:00 +0000

A core sample is a cylindrical section of a naturally occurring medium consistent enough to hold a layered structure. Most cores are obtained by drilling into the medium, for example sediment or rock, with a hollow steel tube called a corer. The hole made for the core sample is called a core hole. A variety of corers exist to sample different media under different conditions. More continue to be invented. In the coring process the sample is pushed more or less intact into the tube. Removed from the tube in the laboratory, it is inspected and analyzed by different techniques and equipment depending on the type of data desired. Analysis is generally non-destructive of most of the sample.

Methods

* gravity coring, in which the core sampler is dropped into the sample
* drilling exploration diamond drilling
* vibracoring, in which the sampler is vibrated to allow penetration into thixotropic media.

Management of cores and data

Coring is the method to retrieve cores samples from the ground. Coring is often utilised in ocean drilling and surveying. Scientist often using coring to acquire core samples for study.

Drilling equipment is often used for coring. Rock core is often taken during mineral exploration operations to help determine the rock type and amount of mineralisation present. A diamond impregnated core bit is used which is rotated to cut an annulus of rock, producing a rock core which extends through the bit into the core barrel. In a wireline system, the core barrel can be retrieved using a wire cable that is run inside the drill rods. Thus, the drill rods do not have to be removed from the borehole each time a core run is complete. Diamond coring can be carried out to depth of 2000m using conventional mineral exploration drilling equipment. Core can be recovered from deeper wells but the operation becomes more expensive.

The technique of coring long predates attempts to drill into the Earth’s mantle by the Deep Sea Drilling Program. The value to oceanic and other geologic history of obtaining cores over a wide area of sea floors soon became apparent. Core sampling by many scientific and exploratory organizations expanded rapidly. To date hundreds of thousands of core samples have been collected from floors of all the planet’s oceans and many of its inland waters.

Access to many of these samples is facilitated by the Index to Marine & Lacustrine Geological Samples,

"A collaboration between twenty institutions and agencies that operate geological repositories."

The above agency keeps a record of the samples held in the repositories of its member organizations. Data includes

"Lithography, texture, age, principal investigator, province, weathering/metamorphism, glass remarks and descriptive comments"

Layering

Any natural medium at or under the Earth’s surface or other body that is consistent enough to maintain a solid or semi-solid structure is layered. The layering comes from successive deposition or growth in time of structural or compositional variants of the medium.

Most familiar to us are the stratigraphic layers of the Earth’s surface on which the geologic history of the surface is based; for example, the Eocene, Oligocene, Miocene, etc. Each layer in this case contains distinctive fossils generated by the evolution of species. Layers often are divided into sublayers.

Layering is more pervasive than the broad outline of the Geologic Time Scale leads us to believe. Any change in environment causes a new layer to be deposited. A succession of plant species in a region, for example, causes a succession of layers containing different pollen in ice and mud. Variation in rainfall causes tree rings to be of different widths.

Informational value of core samples

Scientific coring began as a method of sampling the ocean floor. It soon expanded to lakes, ice, mud, soil and wood. Cores on very old trees give information about their growth rings without destroying the tree.

Cores indicate variations of climate, species and sedimentary composition during geologic history. The dynamic phenomena of the Earth’s surface are for the most part cyclical in a number of ways, especially temperature and rainfall.

There are many ways to date a core. Once dated, it gives valuable information about changes of climate and terrain. For example, cores in the ocean floor, soil and ice have altered the view of the geologic history of the Pleistocene entirely.

From http://en.wikipedia.org/

Chat (mining)

noreply@blogger.com (Unknown) — Tue, 23 Feb 2010 04:57:00 +0000

Chat is a term for fragments of siliceous rock, limestone, and dolomite waste rejected in the lead-zinc milling operations that accompanied lead-zinc mining in the first half of the twentieth century. Historic lead and zinc mining in the Midwestern United States was centered in two major areas: the Tri-State area covering more than 2,500 square miles (6,500 km2) in southwestern Missouri, southeastern Kansas, and northeastern Oklahoma and the Old Lead Belt covering about 110 square miles (280 km2) in southeastern Missouri. The first recorded mining occurred in the Old Lead Belt in about 1742. The production increased significantly in both the Tri-state area and the Old Lead Belt during the mid-1800s and lasted up to 1970.

Cleanup

Currently production still occurs in a third area, the Viburnum Trend, in southeastern Missouri. Mining and milling of ore produced more than 500 million tons of wastes in the Tri-State area and about 250 million tons of wastes in the Old Lead Belt. More than 75 percent of this waste has been removed, with some portion of it used over the years. Today, approximately 100 million tons of chat remain in the Tri-State area. The EPA, the states of Oklahoma, Kansas and Missouri, local communities, and private companies continue to work together in implementing and monitoring response actions that reduce or remove potential adverse impacts posed by remaining mine wastes contaminated with lead, zinc, cadmium, and other metals.

Ore processing

Ore production consisted of crushing and grinding the rock to standard sizes and separating the ore. Ore processing was accomplished in either a dry gravity separation or through a wet washing or flotation separation. Dry processes produced a fine gravel waste commonly called “chat.” The wet processes resulted in the creation of tailing ponds used to dispose of waste material after ore separation. The wastes from wet separation are typically sand and silt size and are called “tailings.” Milling produces large chat waste piles and flat areas with tailings deposited in impoundments. Tailings generally contain higher concentrations of heavy metals and therefore present a higher risk to human health and the environment through direct contact. Chat typically ranges in diameter from 1/4 to 5/8 inch. Intermingled material such as sands measure 0.033-0.008 inches in diameter and fine tailings are less than 0.008 inches (0.20 mm) in diameter.

Uses for chat

Chat piles appear grayish white in color and impact surrounding environments severely. Chat can be used to sprinkle on snow-covered roads to improve traction, as gravel, concrete aggregate, and asphalt pavement. These chats, found as huge man-made mounds in that county, are utilized as construction aggregate, principally for railroad ballast, highway construction, and concrete production.

From http://en.wikipedia.org/

Cave-in

noreply@blogger.com (Unknown) — Mon, 08 Feb 2010 16:32:00 +0000

A cave-in is a collapse of a geologic formation, mine or structure which typically occurs during mining or tunneling. Geologic structures prone to cave-ins include alvar, tsingy and other limestone formations, but can also include lava tubes and a variety of other subsurface rock formations.

In mining, the term roof fall is used to refer to a range of collapses, ranging from the fall of a single flake of shale to collapses that form sink holes that reach to the surface. Note that roof falls in mining are not all accidental. In longwall mining and retreat mining, miners systematically remove all support from under large areas of the mine roof, allowing it to settle just beyond the work area. The goal in such mining methods is not to prevent roof fall and the ensuing surface subsidence, but to control it.

From http://en.wikipedia.org/

Alicanto

noreply@blogger.com (Unknown) — Thu, 04 Feb 2010 20:08:00 +0000

The Alicanto or Allicanto is a mythological bird of the desert of Atacama, pertaining to Chilean mythology.

Legend

The legend says that the alicanto's wings shine during the night with beautiful, metallic colors, and their eyes emit strange lights; making a luminous flight some would not project shade on the desert.

This bird brings luck to any miner who sees it. Alicanto live in small caves between hills containing minerals, and feed on gold and silver.

If the lucky miner follows an alicanto without being caught, they can find silver or gold. But, if the alicanto discovers them, the bird will guide the greedy miner off a cliff, causing them to fall to their death.

Alicanto should not be confused with the Alicante, a fictional Mexican snake that drinks mother's milk and impregnates women, or uses the human stomach as a living place.

From http://en.wikipedia.org/

School of mines

noreply@blogger.com (Unknown) — Fri, 22 Jan 2010 12:09:00 +0000

A school of mines (or mining school) is a term used for many engineering schools established in the 18th and 19th centuries that originally focused on mining engineering and applied science. Most no longer primarily teach mining-related subjects, although some have retained the name.

Universities offering degrees in mining engineering

North America

United States (ABET-accredited Mining Engineering)

* University of Alaska Fairbanks, College of Engineering and Mines, Fairbanks, Alaska
* University of Arizona, Department of Mining & Geological Engineering, Tucson
* Colorado School of Mines, Mining Engineering, Golden, CO
* University of Kentucky, Lexington, KY
* Missouri University of Science and Technology (formerly the Missouri School of Mines & Metallurgy), Rolla, Missouri
* Montana Tech of the University of Montana (formerly Montana School of Mines), Butte, MT
* University of Nevada, Reno (formerly The Mackay School of Mines) Reno, Nevada
* New Mexico Institute of Mining and Technology, Socorro, New Mexico
* Pennsylvania State University, University Park, PA
* Southern Illinois University at Carbondale, Carbondale, IL
* University of Utah, Department of Mining Engineering, Salt Lake City, Utah
* Virginia Polytechnic Institute and State University, Blacksburg, VA
* West Virginia University, in Morgantown, WV
* South Dakota School of Mines and Technology, Rapid City, SD

United States (non ABET-accredited or other programs)

* Michigan Technological University, Houghton, Michigan, offers a graduate program (MS and PhD) in Mining Engineering
* South Dakota School of Mines and Technology, Rapid City, SD, offers a degree in Mining Engineering and Management.

Canada

* Lassonde Mineral Engineering, University of Toronto, Toronto, Ontario
* McGill University, Montreal
* Norman B. Keevil Institute of Mining Engineering, The University of British Columbia, Vancouver and Kelowna
* Queen's University, Kingston, Ontario
* Mining Engineering, Laurentian University, Sudbury, Ontario
* University of Alberta, School of Mining & Petroleum Engineering,Edmonton, Alberta
* Dalhousie University, Halifax, Nova Scotia

Europe

* Imperial College London
* University of Glamorgan (formerly the Welsh School of Mines), Pontypridd, Glamorgan, UK
* Camborne School of Mines, Cornwall, United Kingdom
* Ecole Nationale Supérieure de Géologie, Nancy
* Ecole des Mines, Paris
* École Nationale Supérieure des Mines de Saint-Étienne, Saint-Étienne, France
* Groupe des écoles des mines, seven engineering schools in France
* Technische Universität Bergakademie Freiberg, Freiberg, Germany, the oldest Academy of Mining in the world, founded in 1765
* Faculty of Mining and Geology, University of Belgrade, Serbia
* Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Croatia
* Faculty of Mining and Geology, Silesian University of Technology, Gliwice, Poland
* Faculty of Geoengineering, Mining and Geology, Wroclaw University of Technology, Wroclaw, Poland
* Instituto Superior Técnico da Universidade Técnica de Lisboa, Lisbon, Portugal
* Escuela Técnica Superior de Ingenieros de Minas de Madrid, Universidad Politécnica de Madrid, Madrid, Spain
* Escuela Técnica Superior de Ingenieros de Minas de Oviedo/Escuela Téunica d'Inxenieros de Mines d'Uviéu, Universidad de Oviedo/Universidá d'Uviéu, Oviedo/Uviéu, Spain
* Helsinki University of Technology, Helsinki, Finland
* Technische Universiteit Delft, Delft, The Netherlands
* Department of Natural Resources, Katholieke Universiteit Leuven, Leuven, Belgium
* Faculty of Mining Engineering and Metallurgy, National Technical University of Athens, Greece
* Moscow State Mining University, Russia
* Saint Petersburg Mining Institute, Saint Petersburg, Russia
* Faculty of Mines, Istanbul Technical University, Istanbul, Turkey

Africa

* University of Pretoria, Pretoria, South Africa
* University of the Witwatersrand, Johannesburg, South Africa
* University of Dar-es-salaam, Tanzania
* The Mohammadia School of Engineering, Department of Mineral Engineering, Rabat, Morocco
* Department of Mining Engineering, University of Zimbabwe, Harare, Zimbabwe
* School of Mines, Bulawayo Polytechnic College and National University of Science and Technology, Bulawayo, Zimbabwe
* Zimbabwe School of Mines, Killarney, Bulawayo, Zimbabwe

South America

* Escola Politécnica, Universidade de São Paulo, São Paulo, Brazil
* Department of Mining Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
* Universidade Federal de Ouro Preto (formerly Escola de Minas de Ouro Preto, Minas Gerais, Brazil
* Faculdade de Engenharia, Universidade do Estado de Minas Gerais , João Monlevade, Brazil
* Department of Mining Engineering , University Federal of Pernambuco (UFPE), Recife, Pernambuco, Brazil.
* Department of Mining Engineering, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil
* Department of Mining Engineering, Universidade Federal da Bahia, Salvador, Bahia, Brazil
* Facultad de Ingenieria de Minas, Pontificia Universidad Catolica del Peru (PUCP)
* Escuela Profesional de Ingeniería de Minas, Universidad Nacional Daniel Alcides Carrión, Cerro de Pasco, Peru.
* Mining Engineering Department, University of Chile, Santiago, Chile
* Departamento de Ingeniería en Minas, Universidad de Santiago de Chile, Santiago, Chile
* Centro de Minería, Pontificia Universidad Católica de Chile, Santiago, Chile
* Faculty of Mines, Universidad Nacional de Colombia, Sede Medellín, Colombia

Asia

* Indian School of Mines University, Dhanbad, India
* IIT Kharagpur, Kharagpur, India
* NIT Karnataka, Surathkal, India
* NIT Rourkela, Orissa, India
* Visvesvaraya National Institute of Technology(NIT Nagpur), Maharashtra, India
* NIT Raipur, Chattisgarh, India
* Banaras Hindu University, Department of Mining Engineering, Varanasi, India
* Bengal Engineering & Science University, Howrah, India
* Guindy Engineering College, Anna University, Chennai, India
* Kothagudem School of Mines, Kothagudem, India
* University of Tehran, Department of Mining Engineering, Tehran, Iran
* International University of Imam Khomeini, Qazvin, Iran

Australia

* School of Civil and Resource Engineering , University of Western Australia
* School of Civil, Environmental and Mining Engineering , University of Adelaide, South Australia
* University of Wollongong, New South Wales
* School of Mining Engineering, University of New South Wales, Sydney
* School of Mining Engineering, University of Queensland, Brisbane
* School of Science and Engineering, University of Ballarat, Victoria
* Western Australian School of Mines, Kalgoorlie, Western Australia
* Melbourne School of Engineering, University of Melbourne, Victoria offers a Master of Mining Engineering
* The South Australian School of Mines and Industries, established 1889, is now part of the University of South Australia

From http://en.wikipedia.org/

Industrial Revolution

noreply@blogger.com (Unknown) — Sun, 17 Jan 2010 23:45:00 +0000

The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, and transport had a profound effect on the socioeconomic and cultural conditions starting in the United Kingdom, then subsequently spreading throughout Europe, North America, and eventually the world. The onset of the Industrial Revolution marked a major turning point in human history; almost every aspect of daily life was eventually influenced in some way.

Starting in the later part of the 18th century there began a transition in parts of Great Britain's previously manual labour and draft-animal–based economy towards machine-based manufacturing. It started with the mechanisation of the textile industries, the development of iron-making techniques and the increased use of refined coal. Trade expansion was enabled by the introduction of canals, improved roads and railways. The introduction of steam power fuelled primarily by coal, wider utilisation of water wheels and powered machinery (mainly in textile manufacturing) underpinned the dramatic increases in production capacity. The development of all-metal machine tools in the first two decades of the 19th century facilitated the manufacture of more production machines for manufacturing in other industries. The effects spread throughout Western Europe and North America during the 19th century, eventually affecting most of the world, a process that continues as industrialisation. The impact of this change on society was enormous.

The first Industrial Revolution, which began in the 18th century, merged into the Second Industrial Revolution around 1850, when technological and economic progress gained momentum with the development of steam-powered ships, railways, and later in the 19th century with the internal combustion engine and electrical power generation. The period of time covered by the Industrial Revolution varies with different historians. Eric Hobsbawm held that it 'broke out' in Britain in the 1780s and was not fully felt until the 1830s or 1840s, while T. S. Ashton held that it occurred roughly between 1760 and 1830. Some twentieth century historians such as John Clapham and Nicholas Crafts have argued that the process of economic and social change took place gradually and the term revolution is not a true description of what took place. This is still a subject of debate among historians. GDP per capita was broadly stable before the Industrial Revolution and the emergence of the modern capitalist economy. The Industrial Revolution began an era of per-capita economic growth in capitalist economies. Historians agree that the Industrial Revolution was one of the most important events in history.

From http://en.wikipedia.org/

Hushing

noreply@blogger.com (Unknown) — Fri, 15 Jan 2010 00:41:00 +0000

Hushing is an ancient mining method using a flood or torrent of water to reveal mineral veins. The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden below soil and sub-soil, which must be stripped away to discover the ore veins. A flood of water is very effective in moving soil as well as working the ore deposits when combined with other methods such as fire-setting. It was used during the formation and expansion of the Roman Empire from the first century BC on to the end of the empire. It is now redundant except in a variant known as hydraulic mining, where jets or streams of water are used to break down deposits, especially of alluvial gold and alluvial tin.

History

The method is well described by Pliny the Elder in Book XXXIII of his Naturalis Historia from the first century AD. He distinguishes the use of the method for prospecting for ore and use during mining itself. It was used during the Roman period for hydraulic mining of alluvial gold deposits, and in opencast vein mining, for removal of rock debris, created by mechanical attack and fire-setting. He describes how tanks and reservoirs are built near the suspected veins, filled with water from an aqueduct, and the water suddenly released from a sluice-gate onto the hillside below, scouring the soil away to reveal the bedrock and any veins occurring there. The power behind a large release of water is very great, especially if it forms a single water wave, and is well known as a strong force in coastal erosion and river erosion. The method was most effective when used on steep ground such as the brow of a hill or mountain, the force of falling water lessening as the slope becomes smaller.

If veins of ore were found using the method, then hushing could also remove the rock debris created when attacking the veins. Pliny also describes the way hillsides could be undermined, and then collapsed to release the ore-bearing material. The Romans developed the method into a sophisticated way of extracting large alluvial gold deposits such as those at Las Medulas in northern Spain, and for hard rock gold veins such as those at Dolaucothi in Wales. The development of the mine at Dolaucothi shows the versatility of the method in finding and then exploiting ore deposits.

There are the remains of numerous tanks and reservoirs still to be seen at the site, one example being shown at left. It was a small tank built for prospection on the north side of the isolated opencast north of the main mine. It was presumably built to prospect the ground to one side of the opencast for traces of the gold-bearing veins extending to the north. It failed to find the veins here, so was abandoned. It probably precedes the construction of the 7 mile long aqueduct supplying the main site, and was fed by a small leat from a tributary of the river Cothi about a mile further north up the valley. The method could be applied to any ore type, and succeeded best in hilly terrain. The Romans were well experienced in building the long aqueducts needed to supply the large volumes of water needed by the method, and was probably directed by army engineers.

Earlier evidence

The earlier history of the method is obscure, although there is an intriguing reference by Strabo writing ca 25 BC in his Geographica, to gold extraction in the Val d'Aosta in the Alps. He describes the problem gold miners had with a local tribe because of the great volumes of water they had taken from the local river, reducing it to a trickle and so affecting the local farmers. Whether or not they used the water for hushing remains unknown, but it seems possible because the method requires large volumes of water to be operated. Later, when the Romans assumed control of the mining operations, the locals charged them for using the water. The tribe occupied the higher mountains and controlled the water sources, and had not yet been subdued by the Romans.

The historian Polybius, who lived from 220 to 170 BC was writing much earlier in The Histories, and he records that gold mining in the Alpine region was so successful that the price of gold in Italy fell by a third during this period. From his description of large nuggets, and the find being made only two feet below the ground level, with deposits reaching down to 15 feet, it is likely to have been an alluvial deposit where water methods such as hushing would have been very effective. Modern attempts to identify the mines point to one especially large ancient gold mine at Bessa in Northern Italy. It appears to have been worked intensively in pre-Roman days and continued to expand with Roman involvement. The scale of the aqueducts there seems to support Strabo's comments.

Later examples

The technique appears to have been neglected through the medieval period, because Georg Agricola, writing in the 15th century in his De Re Metallica, does not mention hushing at all. On the other hand, he does describe the many uses of water power, especially for washing ore and driving watermills.

However, the technique was used on a large scale in the lead mines of northern Britain from Elizabethan times onwards. The method is described in the Royal Commission on Children in Mines in 1842 in relation to children being used in the lead mines of the Pennines. The remnants of the "hush gullies" are visible at many places in the Pennines as well as at many other locations such as the extensive lead mines at Cwmystwyth in Ceredigion, and at the Stiperstones in Shropshire.

One famous and spectacular example is the Great Dun Fell hush gully near Cross Fell, Cumbria, probably formed in Georgian era in the search for lead and silver. The gully is about 100 feet deep, carries a small stream, and is a prominent landmark on the bleak moors.

Although the Cornish did not use the term "hushing", there is at least one reference to the technique being used at Tregardock in North Cornwall. Around 1580 mine adventurers used the method to work a lead-silver deposit, although lives were lost in the attempt.

From http://en.wikipedia.org/

Hurrying

noreply@blogger.com (Unknown) — Tue, 05 Jan 2010 15:56:00 +0000

A hurrier, also sometimes called a coal drawer, was a child or woman employed by a collier to transport the coal that they had mined. Woman would normally get the children to help them because of the dificulty of carrying the coal. Common particularly in the early 19th century, the hurrier pulled a corf (baskets or small wagons) full of coal along roadways as small as 16 inches in height. They would often work 12 hour shifts, making several runs down to the coal face and back to the surface again.

Some children came from the workhouses and were apprenticed to the colliers. Adults could not easily do the job because of the size of the roadways, which were limited on the grounds of cost and structural integrity. Hurriers were equipped with a "gurl" belt – a leather belt with a swivel chain linked to the corf. They were also given candles as it was too expensive to light the whole mine.

Roles

Children as young as three or four were employed, with both sexes contributing to the work. The younger ones often worked in small teams, with those pushing the corf from the rear being known as thrusters. The thrusters often had to push the corf using their heads, leading to the hair on their crown being worn away and the child becoming bald.

Some children were employed as coal trappers, particularly those not yet strong enough to pull or push the corf. This job saw the child sit in a small cutting waiting for the hurriers to approach. They would then open the trapdoors to allow the hurrier and his cargo through. The trappers also opened the trapdoors to provide ventilation in some locations.

As mines grew larger the volume of coal extracted increased beyond the pulling capabilities of children. Instead horses guided by coal drivers were used to pull the corves. These drivers were usually older children between the ages of 10 and 14.

Legislation

In August 1842 the Children's Employment Commission drew up an act of Parliament which gave a minimum working age for boys in mines, though the age varied between districts and even between mines. The Mines and Collieries Act also outlawed the employment of women and girls in mines. In 1870 it became compulsory for all children aged between five and thirteen to go to school, ending much of the hurrying. It was still a common profession for school leavers well into the 1920s.

The 1969 song The Testimony Of Patience Kershaw by Frank Higgins centres around the testimony of Patience Kershaw when she spoke to the Children's Employment Commission.

From http://en.wikipedia.org/

History of coal mining

noreply@blogger.com (Unknown) — Sun, 03 Jan 2010 14:41:00 +0000

Due to its abundance, coal has been mined in various parts of the world throughout history and continues to be an important economic activity today. Compared to wood fuels, coal yields a higher amount of energy per mass and could be obtained in areas where wood is not readily available. Though historically used as a means of household heating, coal is now mostly used in industry, especially in smelting and alloy production, as well as electricity generation.

Large-scale coal mining developed during the Industrial Revolution, and coal provided the main source of primary energy for industry and transportation in the West from the 18th century to the 1950s. Coal remains an important energy source, due to its low cost and abundance when compared to other fuels, particularly for electricity generation. However, coal is also mined today on a large scale by open pit methods wherever the coal strata strike the surface and is relatively shallow.

Britain developed the main techniques of underground coal mining from the late 18th century onward with further progress being driven by 19th century and early 20th century progress.

However oil and its associated fuels began to be used as alternative from this time onward. By the late 20th century coal was for the most part replaced in domestic as well as industrial and transportation usage by oil, natural gas or electricity produced from oil, gas, nuclear power or renewable energy sources.

Since 1890, coal mining has also been a political and social issue. Coal miners' labour and trade unions became powerful in many countries in the 20th century, and often the miners were leaders of the Left or Socialist movements (as in Britain, Germany, Poland, Japan, Canada and the U.S.) Since 1970, environmental issues have been increasingly important, including the health of miners, destruction of the landscape from strip mines and mountaintop removal, air pollution, and coal combustion's contribution to global warming.

From http://en.wikipedia.org/

Gold rush

noreply@blogger.com (Unknown) — Sat, 02 Jan 2010 01:16:00 +0000

A gold rush is a period of feverish migration of workers into the area of a dramatic discovery of commercial quantities of gold. Gold rushes took place in the 19th century in Australia, Brazil, Canada, South Africa, and the United States.

Gold rushes were typically marked by a general buoyant feeling of a "free for all" in income mobility, in which any single individual might become abundantly wealthy almost instantly. The significance of gold rushes in history has given a longer life to the term, and it is now applied generally to denote any capitalist economic activity in which the participants aspire to race each other in common pursuit of a new and apparently highly lucrative market, often precipitated by an advance in technology.

Gold rushes helped spur permanent non-indigenous settlement of new regions and define a significant part of the culture of the North American and Australian frontiers. As well, at a time when money was based on gold, the newly-mined gold provided economic stimulus far beyond the gold fields. Gold rushes presumably extend back as far as gold mining, to the Roman Empire, whose gold mining was described by Diodorus Siculus and Pliny the Elder, and probably further back to Ancient Egypt.

There are about 13 million to 20 million small-scale miners around the world, according to Communities and Small-Scale Mining (CASM). Approximately 100 million people are directly or indirectly dependent on small-scale mining. There are 800,000 to 1.5 million artisanal miners in Democratic Republic of Congo, 350,000 to 650,000 in Sierra Leone, and 150,000 to 250,000 in Ghana, with millions more across Africa.

Life cycle of a gold rush

Within each mining rush there is typically a transition through progressively higher capital expenditures, larger organizations, and more specialized knowledge. They may also progress from high-unit value to lower unit value minerals (from gold to silver to base metals).

The rush is started by a discovery of placer gold made by an individual. At first the gold may be washed from the sand and gravel by individual miners with little training, using a gold pan or similar simple instrument. Once it is clear that the volume of gold-bearing sediment is larger than a few cubic meters, the placer miners will build rockers or sluice boxes, with which a small group can wash gold from the sediment many times faster than using gold pans. (See placer mining for details.) Winning the gold in this manner requires almost no capital investment, only a simple pan or equipment that may be built on the spot, and only simple organization. The low investment, the high value per unit weight of gold, and the ability of gold dust and gold nuggets to serve as a medium of exchange, allow placer gold rushes to occur even in remote locations.

After the sluice-box stage, placer mining may become increasingly large scale, requiring larger organizations, and higher capital expenditures. Small claims owned and mined by individuals may need to be merged into larger tracts. Difficult-to-reach placer deposits may be mined by tunnels. Water may be diverted by dams and canals to placer mine active river beds or to deliver water needed to wash dry placers. The more advanced techniques of ground sluicing, hydraulic mining, and dredging may be used.

Typically the heyday of a placer gold rush would last only a few years. The free gold supply in stream beds would become depleted somewhat quickly, and the initial phase would be followed by prospecting for veins of lode gold that were the original source of the placer gold. Hardrock mining, like placer mining, may evolve from low capital investment and simple technology to progressively higher capital and technology. The surface outcrop of a gold-bearing vein may be oxidized, so that the gold occurs as native gold, and the ore needs only to be crushed and washed (free milling ore). The first miners may at first build a simple arrastre to crush their ore; later, they may build stamp mills to crush ore more quickly. As the miners dig down, they may find that the deeper part of vein contains gold locked in sulfide or telluride minerals, which will require smelting. If the ore is still sufficiently rich, it may be worth shipping to a distant smelter (direct shipping ore). Lower-grade ore may require on-site treatment to either recover the gold or to produce a concentrate sufficiently rich for transport to the smelter. As the district turns to lower-grade ore, the mining may change from underground mining to large open-pit mining.

Many silver rushes followed upon gold rushes. As transportation and infrastructure improve, the focus may change progressively from gold to silver to base metals. In this way, Leadville, Colorado started as a placer gold discovery, achieved fame as a silver-mining district, then relied on lead and zinc in its later days. Butte, Montana began mining placer gold, then became a silver-mining district, then became for a time the world’s largest copper producer.

Gold rushes by region

Australian Gold rushes

The Victorian gold rush, which occurred in Australia in 1851 soon after the California gold rush, was the biggest of several Australian gold rushes. That gold rush was highly significant to Australia’s, and especially Victoria's and Melbourne's, political and economic development. With the Australian gold rushes came the construction of the first railways and telegraph lines, multiculturalism and racism, the Eureka Stockade and the end of penal transportation.

In 1852 alone, 370,000 immigrants arrived in Australia and the economy of the nation boomed. The 'rush' was well and truly on. Victoria contributed more than one third of the world's gold output in the 1850s and in just two years the State's population had grown from 77,000 to 540,000.

The number of new arrivals to Australia was greater than the number of convicts who had landed there in the previous seventy years. The total population trebled from 430,000 in 1851 to 1.7 million in 1871.

Gold rushes happened at or around:

* Coolgardie
* Charters Towers
* Kalgoorlie
* Bathurst
* Bendigo
* Ballarat
* Hill End

North America

The first significant gold rush in the United States was in Cabarrus County, North Carolina (east of Charlotte), in 1799 at today's Reed's Gold Mine. Thirty years later, in 1829, the Georgia Gold Rush in the southern Appalachians occurred. It was followed by the California Gold Rush of 1848–52 in the Sierra Nevada, which captured the popular imagination. The California gold rush led directly to the settlement of California by Americans and the rapid entry of that state into the union in 1850. The gold rush in 1849 stimulated worldwide interest in prospecting for gold, and led to new rushes in Australia, South Africa, Wales and Scotland.- Successive gold rushes occurred in western North America, moving north and east from California: Fraser Canyon, the Cariboo district and other parts of British Columbia, and the Rocky Mountains. Resurrection Creek, near Hope, Alaska was the site of Alaska's first gold rush more than a century ago, and placer mining continues today. Other notable Alaska Gold Rushes were Nome and the Fortymile River.

Klondike

One of the last "great gold rushes" was the Klondike Gold Rush in Canada's Yukon Territory (1898–99), immortalized in the novels of Jack London, the poetry of Robert W. Service and Charlie Chaplin's film The Gold Rush. The main goldfield was along the south flank of the Klondike River near its confluence with the Yukon River near what was to become Dawson City in Canada's Yukon Territory but it also helped open up the relatively new US possession of Alaska to exploration and settlement and promoted the discovery of other gold finds.

South Africa

In South Africa, the Witwatersrand Gold Rush in the Transvaal was important to that country's history, leading to the founding of Johannesburg and tensions between the Boers and British settlers.

South African gold production went from zero in 1886 to 23% of the total world output in 1896. At the time of the South African rush, gold production benefited from the newly discovered techniques by Scottish chemists, the MacArthur-Forrest process, of using potassium cyanide to extract gold from low-grade ore.

Notable gold rushes by date

Rushes of the 1690s

* Brazil Gold Rush, Minas Gerais (1695)

Rushes of the 1800s

* North Carolina Gold Rush, Cabarrus County, North Carolina, US (1799)

Rushes of the 1820s

* Georgia Gold Rush, Georgia, US (1828)

Rushes of the 1840s

* California Gold Rush, California (1848)

Rushes of the 1850s

* Queen Charlottes Gold Rush, British Columbia, Canada (1850); the first of many British Columbia gold rushes
* Victorian Gold Rush, Victoria, Australia
* Fraser Canyon Gold Rush, British Columbia (1858–1861)
* Rock Creek Gold Rush, British Columbia (1859–1860s)
* Pikes Peak Gold Rush, Pikes Peak, Colorado (1859)
* Northern Nevada Gold Rush (from 1850 - 1934)

Rushes of the 1860s

* Idaho Gold Rush, also known as the Fort Colville Gold Rush, near Colville, Washington state (1860)
* Cariboo Gold Rush, British Columbia (1862–65)
* Stikine Gold Rush, British Columbia (1863)
* Big Bend Gold Rush, British Columbia (1865—66)
* Omineca Gold Rush, British Columbia (1869)
* Wild Horse Creek Gold Rush, British Columbia (1860s),
* Black Hills Gold Rush, Black Hills of South Dakota and Wyoming (1863, later extending into Montana)
* Eastern Oregon Gold Rush (1860s–1870s)
* Kildonnan Gold Rush, Sutherland, Scotland (1869)
* Central Otago Gold Rush, New Zealand

Rushes of the 1870s

* Cassiar Gold Rush, British Columbia, 1871
* Palmer River Gold Rush, Palmer River, Queensland, Australia (1872)
* Black Hills Gold Rush, The Black Hills, South Dakota (1874)
* Bodie Gold Rush, Bodie, California (1876)
* Kumara Gold Rush, Kumara and Dillmanstown, New Zealand (1876)
* Hungen, Hesse, Germany (1877)

Rushes of the 1880s

* Witwatersrand Gold Rush, Transvaal, South Africa (1886); the resulting influx of miners was one of the triggers of the Second Boer War
* Cayoosh Gold Rush in Lillooet, British Columbia (1884—87)
* Tulameen Gold Rush near Princeton British Columbia

Rushes of the 1890s

* Tierra del Fuego Gold Rush, Tierra del Fuego, southern Chile and Argentina
* Cripple Creek Gold Rush, Cripple Creek, Colorado (1891)
* Westralia Gold Rush, Kalgoorlie, Western Australia
* Klondike Gold Rush, centered on Dawson City, Yukon, Canada (1896–1898)
* Atlin Gold Rush, Atlin, British Columbia (1898)
* Nome Gold Rush, Nome, Alaska (1898–99)

Rushes of the 1900s

* Fairbanks Gold Rush, Fairbanks, Alaska (1902–1905)
* Goldfield Gold Rush, Goldfield, Nevada
* Cobalt Silver Rush, 1903-5, Cobalt, Ontario, Canada
* Porcupine Gold Rush, 1909-11, Timmins, Ontario, Canada – little known, but one of the largest in terms of gold mined, 67 million ounces as of 2001

Rushes of the 1930s

* Kakamega gold rush, Kenya, 1932

Rushes of the 1970s

* Upper Amazon Gold Rush, Upper Amazon region, Brazil and Peru

Rushes of the 1980s

* Amazon Gold Rush, Amazon region, Brazil
* Mount Kare Gold Rush, Enga Province, Papua New Guinea

Rushes of the 2000s

* Great Mongolian Gold Rush, Mongolia (2001)
* Apuí Gold Rush, Apuí, Amazonas, Brazil (2006); approximately 500,000 miners are thought to work in the Amazon's "garimpos" (gold mines).

From http://en.wikipedia.org/

Geordie lamp

noreply@blogger.com (Unknown) — Sat, 26 Dec 2009 09:41:00 +0000

The Geordie lamp was invented by George Stephenson in 1815 as a solution to explosions due to firedamp in coal mines.

Although controversy arose between Stephenson's design and the Davy lamp, (invented by Humphry Davy in the same year), Stephenson's original design worked on significantly different principles. If the only way air could get to the flame was restricted (a baseplate pierced by a number of small-bore brass tubes was the usual way of doing this) and the lamp body above the flame lengthened, then the same amount of air could get to the flame, but would pass through the flow restriction at a velocity higher than the velocity of the flame in a mixture of firedamp (mostly methane) and air. This, then, prevented an explosive backblast that might light the surrounding air.

Stephenson's design used glass to surround the flame, which cut out less of the light than Davy's, where the gauze surrounded it. But this also posed the danger of breakage in the harsh conditions of mineworking, which problem was not resolved until the invention of safety glass. Stephenson tried several different designs in early years and later adopted Davy's gauze in preference to the tubes and it was this revised design that was used for most of the 19th century as the Geordie lamp.

The name is possibly the route by which 'Geordie' became the familiar and affectionate epithet for Tynesiders, deriving from a diminutive form of the inventor's first name, George.

From http://en.wikipedia.org/

Freeminer

noreply@blogger.com (Unknown) — Thu, 24 Dec 2009 09:18:00 +0000

A Freeminer is the ancient title given to a coal miner in the Forest of Dean, Gloucestershire, UK who has earned the right to mine personal plots known as "gales" within the royal forest.

Eligibility

In order to earn this right, an individual must be male, born within the ancient administrative district known as the "Hundred of St Briavels", (now generally considered to be contiguous with the Forest of Dean (district)), and have worked down a mine for a year-and-a-day. The officer in charge of regulating the freemines and freeminers, including allocating the gales, is known as the Gaveller, a historical post which still exists today.

The rights of the Freeminers are very ancient, and were confirmed by Edward II of England, who in doing so, claimed that the rights of the Freeminers had existed "tyme out of mynde". A plaque bearing the engraved coat of arms of the Freeminers hangs in Newland church, and another in the church of St. Michael in Abenhall.

Present day

Freeminers still operate today, though on a much reduced basis, due to several factors including the closure of mainstream commercial pits in the Forest of Dean, the low price of and demand for coal, the relatively high costs of small-scale extraction, the closure of maternity hospital facilities - such that it will be impossible to be born within the "Hundred of St Briavels" - and attempts by the UK government to exact commercial operating licence charges out of these small-scale producers. However, despite the modest level of activity, Freemining tradition remains an important part of local identity, and some Freemines operate successfully, especially through diversification into non-traditional areas, such as tourism and ochre mining at Clearwell Caves.

From http://en.wikipedia.org/