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By W. P. Diamond, F. Garcia, J. K. Marshall

Many longwall mines rely on methane drainage to supplement traditional fan-based ventilation systems. However, the surface production facilities for methane drainage systems, including gob gas ventholes, are commonly located in remote locations, sometimes without convenient access to electrical power, and they may be monitored infrequently. The first evidence that a methane drainage system may not be operating efficiently, or not operating at all, can be an increase in methane concentrations at a return air shaft or underground where the workforce is exposed to the risk of a methane explosion. A solar powered, remote gob gas venthole monitoring and cellular telephone-based real-time data transmission system has been developed and successfully field tested by the National Institute for Occupational Safety and Health (NIOSH) to address this problem. With this system, individual methane drainage boreholes can be monitored from the mine office to determine current operational performance parameters, as well as review past data to anticipate maintenance needs and troubleshoot operational problems.

By Michael Day, Paul Kos, Scott Brinton

A hydrogeologic characterization and impact analysis was performed for a proposed quarry at the Hitch Rack Ranch located in the Little Turkey Creek watershed southwest of Colorado Springs, Colorado. Continuous multiple channel tubing, nested piezometers, stream flow measurements, and mapping of known seeps were used to define the three-dimensional potentiometric distribution and areas of groundwater recharge and discharge. Water balance considerations, mass balance calculations, and potentiometric response to earth tides and barometric fluctuations confirmed that the granite fracture system in the ridge area of the proposed quarry has an extremely low bulk hydraulic conductivity resulting in minimal groundwater discharge to sustain the baseflow of Little Turkey Creek. The Little Turkey Creek valley forms the major conduit for groundwater flow exiting from the upper part of watershed underlain by granite. This conclusion has significant implications with respect to mine planning to minimize projected impacts to the hydrologic system and preserve this recharge component to downgradient Denver Basin sedimentary deposits.

By D. P. Venter

When Oryx Mine down-scaled in 1994, focus was placed on development, with the primary aim being the exposure and proving of ore reserves. In order to achieve this aim, development ends had to be advanced to reef at the maximum possible rate. This in turn called for support methods which could keep up with the advancing faces, taking up minimum space and time for installation, while providing on the face a real coverage and effective long-term support. In the majority of the development ends which were located in fairly competent ground, the grouted rod development support proved to be adequate until such time as secondary support in the form of meshing and lacing could be installed. The ends developing towards the eastern boundary of the mine, especially in the ?C? block, encountered extremely adverse ground conditions due to the presence of smectite zones within the footwall quartzites. Smectites are a group of montmorillonite clay materials, mainly composed of hydrous aluminosilicates. They occur as minute platy crystals in the rock mass and are especially notable for their ability to absorb liquids. Generally, the zones are found in between the bedding planes of the host rock, and may vary considerably in thickness over short distances. Wherever the smectites were exposed by the development blasting, the rockwalls weathered as the smectites absorbed water and the condition of the tunnel rockwalls deteriorated rapidly. When the smectites were left exposed and allowed to weather, it became almost impossible to install secondary permanent support such as meshing and lacing at a later stage. To minimise the exposure time and subsequent deterioration of the smectite zones, it was recommended that all development ends encountering smectites be shotcreted as soon as possible after blasting. In developing a shotcreting support methodology, both a drycreting and wetcreting system were investigated. The situation at the time ruled out the use of a wetcreting system on the basis of the extensive and costly infrastructure required, as well as its limited manoeuverability. Instead, it was decided to opt for as maller scale but more manoeuverable drycreting system. The system utilized a number of portable drycrete machines with pre-bagged cement, which could support several development ends in close proximity. Initial trials using normal 30 MPa shotcrete on 19level proved successful and the system was implemented.

Jan 1, 1998

By N. A. Eilertsen

Procedures of mining high-calcium limestone underground at the Kimballton mine of the Standard Lime and Cement Co. in Giles County, west-central Virginia, are described. Drilling and blasting procedures arc discussed in detail, and direct mining costs are tabulated in percentage of total cost. Output, about 1,725 tons of limestone a day, is attained with heavy trackless equipment by the room and pillar method of ruining; modified by benching floors. Operating features include underground air compression, electric-eye control of curtained doorways, use of a single jumbo drill rig for all drilling, and an effective plan for maintenance of equipment. The company's safety program has contributed to an outstanding safe mining record. The mina is integrated with a plant on the property which converts the stone to metallurgical and chemical grade lime.

Jan 1, 1964

The geological features of the destructive plate margins of the southwest Pacific favour the formation of porphyry type deposits. The major controlling factor favouring the formation of gold-rich deposits of this type is a dense crust. This results in shallow intrusion of large magma bodies beneath andesite stratovolcanoes. Where the intrusives have near vertical sides, the comparatively low temperature of transfer of volatiles from the solidifying melt favours the partitioning of gold into bubbles of volatiles. They reduce the viscosity and density of the melt, resulting in the upward movement of a mineralised melt. With the drop of pressure with upward movement the bubbles separate into a two phase mixture, triggering freezing of the mineralised melt and the formation of a gold mineralised stockwork.

Jan 1, 1995

By Shemek Oginski

The 5 km (16,194 lf) of 6.1m (20 ft) diameter TBM driven tunnel built by the J.F.Shea Co. will serve as sewage overflow storage. The TBM tunnel and four connecting tunnels excavated by drill and blast methods in hard granite will remain unlined. Based on the Geotechnical Baseline Report (GBR), the Contract documents provided a design with no required pattern of rock bolts, no probing, no pre-excavation or consolidation grouting, and lastly, no final lining of the tunnels was deemed necessary. This paper will provide a general overview of these topics with the emphasis on the actual ground conditions encountered versus the projected conditions provided in the GBR and how the GBR reflected the design of the project. Proposed modifications to the temporary and permanent ground support will be presented and the necessity of probing and pre-excavation grouting will be evaluated.

Jan 1, 2005

By Lutz Markworth, Fernando Parra, Wolfram Jaspers

"The worldwide demand of iron ore and the depletion of the high-purity deposits make it necessary to recover ores in increasingly fine size fractions or low Fe content in the feed material. Impurities for Iron ore processing plants are mainly Silica, Al2O3 and Sulfides.There is a copper processing plant in Chile, which has a high content of Fe in its tailings. These tailings will be re-processed to recover the Fe and to produce a pellet feed concentrate. This challenging flotation process was developed by the customer in his own laboratory. Different flotation technologies were tested. The best results were achieved with the PNEUFLOT® (PNEUmatic FLOTation). For a feed capacity of approximately 600 t/h, a flow sheet of two flotation lines with a reverse two-stage Amine-Silica flotation followed by a single stage reverse Xanthate Pyrite flotation was developed.Because of the two impurities the process control is very critical. Not even the reagent dosing has to be flexible for changes in the feed material; also the flotation cell has to be adaptable. Continuous development of the PNEUFLOT® cell with their specific advantages and the elimination of dysfunctions in the PNEUFLOT® cell have led to a growing demand of this type of equipment worldwide for the iron ore industry within the past years.INTRODUCTIONThe worldwide increasing demand of iron ore is mainly caused by China. This has a major impact on all economics worldwide as the metal price indicates. However, not even the iron ore and steel price, but all other commodities prices and the precious metals prices are increasing by a high percentage. Figure 1 shows the iron ore (pellets) price increase for Fe and the import of iron ore by China. Figure 2 shows the imports of iron ore to China."

Jan 1, 2008

By A. C. Wilson

In 1991, local prospector C. ?Mickey? Clement recovered at least three alluvial diamonds from the Michipicoten River. Two of these stones were sent to the Department of Mineralogy, Royal Ontario Museum, where they were identified as industrial grade diamonds with weights of 1.05 and 1.13 carats. Both stones were described as frosted and graphite-inclusion riddled. In 1995, prospector Sandor Surmacz and geologist Marcelle Hauseux discovered diamonds in bedrock approximately 20 km north of the Michipicoten River. An 18.1-kg bulk sample of a xenolith-rich lamprophyre, taken from an outcrop at the side of the Trans Canada Highway north of Wawa, yielded 1 macro diamond and 5 micro diamonds. All but one was gem quality (Sage 2000). Since then, more than 36 occurrences of diamonds in bedrock have been reported in an approximately 30 km2 area centred 20 km north of the town of Wawa. The occurrences are hosted within a sequence of unusual, Archean-aged, heterolithic breccias previously considered to have no economic significance. Ten kimberlite occurrences also have been confirmed in the Michipicoten greenstone belt in the last 5 years. Two of these kimberlites are diamondiferous. To date, expenditures on property acquisition and diamond exploration in the Wawa are estimated at $120 million (CAN). This paper summarizes the geological observations made on these occurrences and discusses including the relationship between the occurrences and the regional geology.

May 1, 2003

By Richard Mcivor, Largo Albert

"Inco Limited has operated aluminum mine shaft conveyances since 1968. Aluminum conveyances are used where the hoisting in system requires lightweight conveyances to maintain the hoist rope safety factors and mine hoist rope pulls as dictated by government regulations. Inco Ltd. currently has 20 skips (including spares) operating in the Ontario Division mines. The main problems encountered are with galvanic corrosion between dissimilar metals and metal fatigue. This paper will highlight some of the problems encountered and illustrate methods utilized to overcome the problems and improve the conveyances performance.IntroductionAluminum mine shaft conveyances have been in use at Inco Limited's various Sudbury district mines since 1968. All of the conveyances currently in use are skips used for hoisting mine ore and rock. Inco had an aluminum quick change Kimberley-type skip and cage in operation at its Totten Mine in the early 1970s, but this mine is no longer in operation and no further comment will be made.The primary reason why aluminum conveyances are chosen over conventional steel conveyances is because of their light weight. Typically an aluminum conveyance will weigh about 60% to 70% of a steel conveyance of similar design. The lighter weight conveyances will allow higher payloads to be used and still maintain the statutory hoist rope factors of safety. It must be remembered that increasing the payload will increase the power required to raise the load and the hoist will have to have the necessary horsepower for the increased payload or the system will be overloaded.The front dump (Rola-chute) skips are of the bail-less design, i.e. the box structure also supports the load and has the shaft guide shoes attached directly to the side of the box structure. The Copper Cliff North Mine and South Mine skips have a joint in the centre of the conveyance and are installed in the shaft in two sections and connected with pins. This feature allows very long (42 ft) skips to be used in areas where a one-piece bail-type conveyance could not be installed. It is not practical to make sectionalized bail-type conveyances"

Jan 1, 1988

By David R. Gossett

For the 22nd year, the chance to exchange knowledge, experience and business cards drew hundreds of mining and phosphate professionals for a two-day regional Phosphate Conference in Lakeland, Florida Nearly 400 people participated in the October conference, which focused on the phosphate industry?s future success. There were 41 exhibitors, 13 program advertisers and 23 sponsors among those supporting the conference. It was chaired by David Gossett, 2006-2007 SME Florida Section Chairman. In the opening panel session that he chaired, John Garlanger (SME) of Ardaman and Associates posed the questions; ?How successful has the industry been? How do we measure it and what factors contributed to the industry?s success? How long will the ethanol boom last? Can the industry obtain the permits it needs to mine for the next 30 years? Can the industry attract and retain the quality of workers it needs??

Jan 1, 2008

By Michael D. Justason

...a global perspective... In March of 2000, the Japanese Geotechnical Society added "Rapid Load Testing" to their national standard for pile testing. In the year 2000. it is estimated that there will be more than 500 "Rapid Load Tests" on foundations around the world. ...so what is a "Rapid Load Test", and why is it gaining acceptance and popularity?

Jan 1, 2001

Study on Mechanism of Sphalerite Flotation in the Presence of Main Metal Ions by Molecular Mechanics

Sep 13, 2010

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Jan 1, 1994

By L. J. Gardner

Ore pass systems play a critical role in moving broken rock from the workplace to surface, and the integrity of the ore pass excavations is crucial. Over the life of the mine, ore pass integrity deteriorates, which may eventually result in the ore pass no longer being fit for purpose. This paper presents several case studies of successful ore pass rehabilitation exercises.

Jan 1, 2006

By H. Foster Bain

(San Francisco Meeting, October, 1911.) [SECRETARY'S NOTE.-This paper, presented in oral abstract, at the San Francisco meeting, was not at first supposed by Mr. Bain to be required for publication in the Transactions; and the excursion to Japan, in which he took part, immediately after the San Francisco meeting, delayed his presentation of the manuscript. After his return to San Francisco, Mr. Bain, in view of the importance of his paper and its discussion, kindly furnished it in full. The delay in its publication (since it was received in April last) has been due, partly to the circumstance that other contributions had meanwhile acquired the "right of way," and partly to the consideration that, the situation contemplated in Mr. Bain's paper having remained practically unchanged, the paper and its discussion would not lose force or timeliness by this lapse of time.-J. S.] No acute observer of public affairs can have failed to observe a growing disposition on the part of the public to change emphasis in government from political equality to social justice. When our own government was founded it was felt to be sufficient to secure to each individual the fullest possible freedom of opportunity, and such a scheme was excellently adapted to the rapid development of a large territory having a small population. As the number of people in a given area increases, there are more points of contact and conflict; each must move in a smaller orbit, and there must be more regulation. Germany is making faster progress in industry than is any other country. The principal reason is the insistence there on team-play. In Germany there are fewer multimillionaires and more socialists (spelled with either a big or little " S ") than in any other of the leading countries; but Germany wins trade and is steadily improving the conditions of life for her citizens. To some, the change from the freest individualism is welcome; to others it is intensely unacceptable. To this fundamental difference in view-point may be imputed much of the vigor with which the controversy regarding coal-lands has been waged. That present conditions in Alaskan coal-fields are extremely unsatisfactory is generally recognized, but there are wide dif-

Aug 1, 1912

This Bureau of Mines report summarizes the research, development, and evaluation demonstrations conducted by the Bureau of Mines under the Health and Safety Act of 1969 to improve the means of notifying miners underground, who are away from their own phone, that they are being called.

Jan 1, 1977

By Hanns J. Billmayer

This report, which covers the period from April 1975 to November 1975, describes the work performed in compliance with the requirements of Contract No. H0357091. The purpose of this contract was the development of protective canopy concepts applicable to rail haulage equipment used in underground coal mines.

Jan 1, 1976

By D. P. Tripathy

A supply chain encompasses all the activities associated with the flow and transformation of goods from the raw materials stage(extraction), through to the end user. Supply chain management (SCM) is the integration of these activities through improved supply chain relationship, to achieve a sustainable competitive advantage and it rests on its ability to provide the right goods and services when and where needed. The supply chain is the vital component of any company?s value chain which links the operating processes to its supplier and customer. The globalization of business promises to offer new and unique challenges for the supply chain competencies of most firms. Challenges will also increase in the environmental aspects of supply chain often referred to as ?Green Issues?. The supply chain of mining industry comprises of the flow of material and information from the mine site, to processing and loading for transport, to the customer. However, due to recent changing environmental requirements affecting mining and mineral processing operations, increasing attention is given to developing environmental management (EM) strategies for the mineral supply chain. This paper focuses on: ? Environmental factors leading to the development of an extended environmental supply chain, ? Additional challenges presented by the extension, ? Performance measures appropriate for the extended supply chain, ? Developing a general procedure towards achieving and maintaining the green supply chain.

May 1, 2006

The Bureau of Mines is operated to assist in promoting economic development through increased efficiency in the mining, preparation, treatment, and utilization of mineral substances; to aid in conserving mineral resources through preventing waste; and to help the mining industry improve health conditions and increase safety. Accomplishment of those ends is sought through investigation of scientific, technologic, and economic problems of the, mineral industries and dissemination of resulting information. Building materials of mineral origin constitute an important product of mining, and the Bureau makes studies of these in the various fields mentioned. The following commodities come within this classification: Asbestos, anhydrite, asphalt, cement, clay and clay products, diatomite, dolomite, glass and mineral wool, granite, greenstone, gypsum, lightweight building materials, lime, limestone, magnesite, marble, sand, sand and gravel, sandstone, sand-lime brick, slate, soapstone, and trap rock.

Jan 1, 1937

By Enrique Hauser

Discussion of the paper of ENRIQUE HAUSER, presented at the New York meeting, February, 1916, and printed in Bulletin No. 110, February, 1916, pp. 521 to 534. GEORGE A. BURRELL, Pittsburgh, Pa. Mr. Hauser determined the influence of inert gases on the properties of fire-damp mixtures, and one might take some issue with his work on the effect of hydrogen, on those mixtures. It is valuable information to have, but as far as the practical application of it goes, it is not of much significance, because one does not find it in mines, at least not in any appreciable amount. The same Fig. 1.-APPARATUS FUR DETECTING COMBUSTIBLE GASES IN AIR. thing can be said of ethylene. Ethylene is formed in considerable quantities as a product of heat reaction, but normally, in the coal mines, as a result of a great many analyses we have made at the Bureau of Mines, we cannot say that ethylene is a combustible gas found in the fire-damp in coal mines.

Jan 5, 1916