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By Shae K. Kim

The aim of this study is to manufacture magnesium alloys with alkaline earth metal oxides (BeO, CaO, MgO or SrO) additions with the objectives of (1) ensuring safety during processing and applications by raising the ignition temperature and reducing oxidation, (2) protecting the environment by reducing or eliminating use of protective gases, (3) maintaining or improving elevated temperature properties with lower amount of Ca or Sr or rare earth metals when compared with conventionally developed high-temperature magnesium alloys, (4) developing cleaner strip casting and continuous casting processes without hot tearing and (5) obtaining all of these objectives without sacrificing mechanical properties or increasing the cost of magnesium alloys.

Jan 1, 2006

By J. Derwin King, Harrison R. Cooper

Applications of nuclear magnetic resonance (NMR) offer possibilities for on-line sensing of the concentrations of several elements in flowing sample streams. In addition to hydrogen, these elements, generally of low-order atomic number, include aluminum, phosphorus, fluorine, sodium, boron, and lithium contained in minerals having commercial importance. Many such elements have been difficult or impossible to successfully measure on-line using the more familiar X-ray fluorescence and neutron activation analysis techniques. The availability of practical on-stream analysis methods is essential to applying advanced controls to processes incorporating these elements. On-stream NMR instrumentation has been demonstrated in the past for several process applications including, as an example, coal flow and analysis; and the technology has recently been extended to the measurement of phosphorous BPL in Florida beneficiation plants. The technique involves simultaneous sensing of proton (hydrogen) and 31P intensities to provide data for continuous calculation of BPL in the phosphate through calibration to volume fractions of water and solids. Initial operating results are described using the PhospholyzerTM on-stream phosphorous analyzer designed for plant application.

Jan 1, 1990

By C. O. Karacan

Underground longwall mining of coal causes large scale disturbance of the surrounding rock mass. The disturbance can increase the rock mass permeability through a reduction on the stress as well as formation of new fractures in the rock. Methane gas contained in the disturbed rock mass can migrate towards the low pressure mine workings and present an explosion hazard. This paper describes the application of a finite difference program to develop a geomechanical model that predicts permeability changes within the rock mass. The calculated permeabilities are used as input to a reservoir simulator that models methane desorption from the coal matrix, methane release from the rock layers and flow towards the mine excavations. The model also considers the basic characteristics of the mine ventilation network. The geomechanical model uses empirical relationships between fracture permeability and stress to calculate permeability changes around a longwall face. The extent of rock failure is determined using a strain softening model that considers both rock matrix and bedding plane failure. The cave rock (gob) is modeled as a compressible, granulated material. The calculated horizontal and vertical permeabilities around the longwall face are averaged and used as one of the inputs to the reservoir model. The reservoir model was developed and calibrated against records of methane flow at a study mine in southwestern Pennsylvania. Good correlation between actual gas production and model outputs has been achieved. The modeling approach provides a basis for estimating methane inflow and optimizing control measures.

By Henk van Muijen, Jan Willem de Wit

1.1 Profile IHC Holland Merwede IHC Holland Merwede is world market leader in the construction of specialist dredging equipment and large-size custom-built offshore vessels. The clients of IHC Holland Merwede include major dredging companies, oil and gas exploration groups, offshore contractors and government authorities. IHC Holland Merwede is focused on the continuous development and innovation of technology to ensure maximum performance and efficiency of its designs and constructions supplied to the dredging and offshore industries. IHC Holland Merwede has a staff of approximately 2,000 at its locations in Hardinxveld- Giessendam, Kinderdijk, Krimpen aan den IJssel, Sliedrecht, Delfgauw, Goes, Hendrik Ido Ambacht and Heusden. Besides worldwide representations, IHC Holland Merwede has branches in China, Houston (USA), India, the Middle East and Singapore. 1.2 Mission IHC Holland Merwede’s mission is to optimize value by anticipating and satisfying its client’s requirements, with efficient advanced technology solutions. The group’s aim is to be consistently at the forefront of technology development, in the business sectors in which it operates.

By Frank C. Greene

Drilling in Missouri in 1945 dropped slightly from the preceding year. The only notable development was that in the Ballard area in Bates County, where a number of farmers drilled private gas wells with an average depth of a little more than 30o feet. Table 1 gives a summary of activities by counties. The total footage drilled was 36,186 ft. of which 20,489 ft. was by cable tools and 15,697 ft. by rotary tools.

Jan 1, 1946

Micro-computers have made it practical to install a high-speed acquisition system to collect data from a longwall face in near real-time. By simultaneous data analyses using neural networks and fuzzy sets, information regarding longwall mining performance and underground behavior can be provided and forecasting longwall instability and detecting geological anomalies is feasible. This paper presents details of the application of neural networks and fuzzy sets in developing on-line evaluation of longwall roof behavior. Techniques for interpreting longwall shield pressures and characterizing roof conditions are discussed.

Jan 1, 1996

By T. Gibson

It is generally accepted that South African coal mines have gone through the mechanization of most of its underground mines, and while there certainly were a lot of productivity improvements, the lack of visibility on these machines operating underground still leave vast areas for improvement. The average actual cutting time still remains very low, in the 30 per cent area, which leaves significant improvement possible. Currently all analysis is carried out using hand-written reports. Unfortunately this is subjective and often inaccurate because of human interpretation. In addition in order to avoid costly component failure, a monitoring system is required to warn of eminent failures and condition monitoring. The challenge faced was to supply and install a system that was ‘Open’ and could be retrofitted to existing machines in operation because of the current standard of communication links to the underground sections. In addition it was intended to use, existing ‘off the shelf’ software and hardware and adapting this for the harsh underground mining conditions wherever possible in order to reduce costs. As development occurred, as with all technology, doors opened to other opportunities such as, remote access data logging and Internet based reporting. We focused on the Voest Alpine Bergtechnik (VA) range of continuous miners, as need arose to achieve the desired cost improvements because of the strategy of service contracts the subsidiary company, Voest Alpine Mining & Tunnelling (VAMT) offer the mining industry in South Africa. This paper describes a data logging system that has been installed on various continuous miners that provides data in real time, on line, and that could be expanded to any electrically supplied underground mobile or stationary mining machine.

Sep 1, 2001

By John Vergunst

"This paper traces the development of Ontario 's cap lamp standard. Over the years, numerous Coroner's Juries investigating fatal mine accidents have made recommendations with respect to underground lighting. As well, recommendations to improve mine lighting have been made by two Commissions, investigating mine safety in Ontario.During the past few years, the performance of any cap lamp worn by miners involved in serious accidents, have been measured by the Mining Heal/h and Safety Branch. Large variations in light output were found between and among cap lamp types. These variations have been attributed to the lack of quality control on the bulbs, design of the cap lamp head piece and in some cases, poor maintenance.In 1986, a series of underground tests were conducted to establish the minimum light output from cap lamps required to visually identify loose ground. The results of these tests indicated that a cap lamp should produce a minimum peak illuminance of 1500 lux measured at 1.2 metres from the light source. On May 30, 1987, Ontario became the first province in Canada to legislate the minimum amount of light required to visually assess ground conditions. INTRODUCTIONPoor lighting has been identified as a factor which can contribute to mining accidents. Over the past decade, several Coroner's Juries as a result of inquests into mining fatalities, have recommended improved lighting in mines.The Joint Federal-Provincial Inquiry Commission into Safety of Mines and Mining Plants in Ontario, was appointed to report upon the adequacy of existing arrangements and practice s that may affect safety. This Commission completed their report in April 1981, and recommended that inadequate lighting be investigated as a possible cause of all reportable underground accidents, and that a comprehensive research programinto mine lighting be undertaken.In response to the first recommendation, the Mining Health and Safety Branch of the Ministry of Labour, hereafter referred to as the Branch, initiated a program to measure lighting levels in all fatal accident investigations where inadequate lighting was a possible factor."

Jan 1, 1989

This paper looks at the various stages of development of open stope drilling techniques. Due to the structural nature of the orebodies mined by open stoping it has been necessary to review mining methods. In-the-hole hammer drilling proved to be the solution to many problems encountered in horizontal percussion drilling.

Jan 1, 1977

By L. J. Tucker

The magnetite orebody at Pea Ridge strikes NE-SH and dips at about 800 to the SE. The ore is high grade magnetite with a strike length of over 600-m and a maximum width of over 180-m on some of the levels. The shape and the mineral content of the iron orebody have been fairly consistent so far. The iron ore and surrounding basement rocks are Precambrian in age. These rocks are usually very competent, about 400-m of sediments lie over the ore.

Jan 1, 1991

By Wantae Kim

In order to establish the optimized recovery process for heavy minerals from Korean beach sand, we investigated the several physical separation methods such as gravity and magnetic separation followed by mineralogical characterization. There was clear relationship between the particle size and heavy mineral content that heavy minerals were mostly concentrated in the particles below 100mesh. Gravity separation using the spiral and shaking table separators made it possible to concentrate heavy minerals by rejecting the light and coarse particles consist mainly of quartz and other non-valuable minerals. The high-intensity magnetic roll separator and subsequent induced magnetic separator were applied to fractionate magnetic particles according to their magnetic susceptibility. The content of TiO2 of high susceptible ilmenite-rich fraction was 43.98wt.% while those of ZrO2 of non-magnetic and magnetic residue were 6.78wt.% and 3.11wt.%, respectively.

Jan 1, 2006

By B. B. Agrawal

Iron ore fines is an area of concern in India. A possible avenue is to use these fines for sponge ironmaking. Work has been carried out to pelletize these fines with coal and a suitable binder, and cure them in ambient atmosphere to retain in-situ reductant. Pellets were characterized for physical strength and metallisation. Critical factors were granulometry was percentage of coal & binder. In laboratory tests, pellets got metallized faster compared to lump ore. Large-scale trials were conducted in a 12-meter long rotary kiln plant. For 90% metallization, required residence time was only 60 minutes against 240 minutes for lump ore. Coal requirement also decreased. Investigations established the fast reduction nature of pellets. This is due to reduction-reactions occurring simultaneously at many sited within the composite pellets, in addition to the diffusion of reducing gases from the surface of the pellets to its core. The developed process is a value addition in the conventional pelletmaking and is environment-friendly also.

Jan 1, 2006

By G. J. Ackland, K. Saksl, F. Brunke, M. Kohnke, B. Tegner, C. Siemers

The application of titanium alloys is limited to 550°C due to their poor oxidation resistance. It is known that the addition of niobium decelerates the oxidation of titanium alloys whereas elements like vanadium do not improve titanium’s oxidation resistance. The underlying mechanisms are not yet well understood. In the present study, different binary titanium-niobium and titanium-vanadium alloys as well as commercially pure titanium were investigated. Oxidation experiments were carried out at 800°C up to 288 hours followed by metallographic analyses to study the oxide layer morphology as well as the microstructure at the interface. Energy-dispersive X-ray spectroscopy mappings were used to identify possible changes in the distribution of the alloying elements. In addition, micro-focused hard X-ray experiments were performed to layer-wise analyse the phase composition in selected samples. As expected, the niobium containing alloys show a better oxidation performance compared to commercially pure titanium and the titanium-vanadium alloys. The oxide layer consisted of TiO2 and Ti2O3. Depending of the niobium content, a niobium-rich layer developed below the metal-oxide-interface minimising oxygen diffusion into the titanium matrix. Based on these results, the minimal niobium content needed for improved oxidation resistance was identified so that alloys of technical relevance can now be developed.

Jan 1, 2014

By Baki Özüm

Early evaluations of Pasquia Hills kerogen shale deposits by Geological Survey of Canada, Saskatchewan Geological Survey, Manitoba Energy and Mines and Sun Oil Company, using modified Fischer Assay, Rock-Eval and other techniques, estimated recoverable reserves of about 2.6x109 barrels of oil in areas favorable for strip-mining; each metric ton of ore was determined to yield about 30 L to 50 L of shale oil remarkably high in aromatic compounds. Western Petrochemical Corp. (WPC) is holding two Oil Shale Exploration Permits covering about 76,635 hectares in the Pasquia Hills Region of eastern Saskatchewan and conducting a 15-corehole drilling program to determine stratigraphic correlation on both first and second white specks kerogen shale. In this program, correlation will be established between oil yield and oil quality, using different retort techniques, including modified Fischer Assay, steam retort and Rock-Eval. Results will lead to further resource evaluation and to a preliminary engineering design for a shale processing plant, including selection of retort process, upgrading of shale oil to petrochemical feedstock, hydrogen management, energy balance and evaluation of environmental impact.

May 1, 2002

By W. J. Schlitt

Introduction Heap and dump leaching are low-cost metal production techniques that are gaining in popularity among gold and copper producers. However, the flow of solution in heaps and dumps has received little attention in the literature. This is unfortunate since solution flow is one of the few parameters subject to operator control. Thus, solution management may well influence both operating costs and plant performance. Costs aside, there are two important aspects of solution flow to be considered -the metallurgical and the hydrological. Some of the metallurgical factors have recently been discussed (Jackson and Ream, 1980; Schlitt, 1984; Schlitt and Nicolai, 1987). These cover solution application rates and methods, irrigation rates, leach-rest cycles, and nonvertical solution flow. According to Caldwell and Moss (1985), however, the hydrological aspects may be more significant than the metallurgical ones. In particular, a phreatic surface will form when excessive flow leads to an accumulation of water and the associated buildup of pore pressure within the rock pile. Such internal flooding can either originate at the foundation or at some other zone of very low permeability. The latter condition gives rise to an impounded volume of solution, i.e., a perched water table (see Whiting, 1985). Caldwell and Moss point out that a rising zone of saturation is probably the most common cause of dump failures. Of course, such failures have even occurred in heaps that were carefully prepared for leaching (Milligan and Engelhardt, 1984). Thus, flooded conditions and perched water tables represent an important safety consideration as well as having an impact on metallurgical performance. The following sections describe a case history in which a perched water table developed within a copper leach dump. The description includes background information, solution flow rates, and metallurgical data. Then this situation is compared to one involving normal drainage. Description of the leach system The leach dump in the case history is located at a shutdown open pit copper mine. It was built in two lifts, with the second added some 20 years after the first. There is little detailed information available on the initial lift. It was built with rail¬hauled waste and was generally less than 30 m (100 ft) high at the crest. The area available for leaching was about 120 m (400 ft) wide and more than 380 m (1250 ft) long. The dump surface was prepared for leaching by dozing ponds approximately 12 m by 12 m by 2.5 to 3.0 m deep (40 ft by 40 ft by 8 to 10 ft). The ponds were leached by flooding with barren leach solution returned from a scrap iron cementation plant. Based on mill feed at the time, the average waste grade was probably close to 0.4% Cu. The first lift leached well. It accepted high flows, which together with the waste grade, produced a rich pregnant leach solution (PLS). Old records indicate a PLS of "50 lb Cu/ 1000 gal," or about 6 g/L. As later drilling would indicate, such a high tenor led to dissolution of considerable scrap iron that was returned to the dump. The iron then hydrolyzed and settled out on the pond bottoms. In addition, the waste settled substantially so that the unleached crest was 3.0 to 4.5 m (10 to 15 ft) above the ponded area. Eventually, the leachable copper was extracted and the dump became less permeable. Thus, the PLS tenor dropped until it became uneconomical. About ten years later, mining resumed and the decision was made to add another lift to the dump. This was done without giving much thought to a subsequent leach operation. Hence a 24-m (80-ft) lift was built on top of the original dump. The surface of the latter was not prepared in any way, e.g., by leveling and/or deep ripping, prior to over-dumping. Examination of subsequent drill cuttings indicated that the new lift contained about 0.2% Cu, with chalcopyrite and chalcocite (50:50) being the predominant copper minerals. Most of the chalcocite occurred as rimming on the abundant pyrite, with the pyrite to chalcopyrite ratio estimated at 10 to 1. The use of 100- and 120-ton trucks for haulage caused some waste compaction during emplacement. In addition, the host rock itself was relatively soft, being a porphyry intrusive material that was partially altered to clay. As a result of the initial compaction and clay swelling, the rate of water percolation from the new leach ponds was slow and the ponds often contained considerable standing water. Even frequent ripping failed to provide a sustained improvement in the percolation rate. The poor surface permeability was exacerbated by hydrolysis of iron salts which settled as a layer on the pond bottoms. Partly as a result of the permeability problems, metallurgical performance was not up to expectations. These had been based on laboratory tests which showed about 20% copper solubilization in two weeks. Continued copper extraction in the tests also suggested that a substantial percentage of the copper would eventually be recovered. However, the PLS grade in the actual operation peaked briefly at about 0.48 g/L Cu (4 lb Cu/1000 gal), then declined to a range of only 0.24 to 0.36 g/L Cu (2 to 3 lb Cu/1000 gal). The poor leaching was traced to a lack of oxidation of the sulfides. There were two principal observations supporting this conclusion. First, there was no evidence of any heat being generated within the dump. As discussed elsewhere (Schlitt and Jackson, 1981; Hiskey and Schlitt, 1982), pyrite oxidation is quite exothermic and the high pyrite content of the waste should have led to an increase in the temperature of the leach solution as it percolated through the rock pile. Second, there was no sign of any natural convective air flow through the dump.

Jan 1, 1987

By Chi Zhang, Junyi Wu

"The use of permanent stainless steel cathodes for electrorefining and electrowinning of cathode copper had been introduced to the market long time ago and now is a well-accepted technology worldwide. During the last decades, the Chinese copper refinery industry had been growing rapidly and many large scaled production plants had been built. In the modern refineries, permanent stainless steel cathodes are introduced and used instead of traditional starter sheets. The most common steel grade used is austenitic stainless steel S31603 (316L/1.4404), while both S30403 (304L/1.4404) and N08904 (904L/1.4539) have been used depending on the actual working conditions, especially with regarding corrosion environment. While 316L permanent cathode functions well in many plants, different kind of problems, such corrosion and deformation, have been reported. There is therefore an increased need for more suitable material. New stainless steels, such as duplex stainless steels, with better properties have been tried and introduced into the application of permanent stainless steel cathode with satisfied results. The article introduces first the Chinese copper refinery industry and properties of duplex stainless steel in general, and then describes the development of using permanent duplex stainless steel cathode, including the actual working conditions, production of cathode sheets as well as the experiences of application in details. After more than one year’s usage, the advantages of permanent duplex stainless steel cathodes are clear seen.INTRODUCTIONChina has become a major player in the international copper market, accounting for around 40 percent of global refined copper demand. Despite the slowdown of the Chinese economy, the consumption of copper products will still increase, but with a medium and/or low growth which will be the new situation for the coming years. The average growth rate is expected to be around 5 percent per annual. In the coming Five-Year plan for National Economic and Social Development a number of initiatives will be finalized which will require massive amounts of copper. In 2015, the expected consumption of copper products will be over 9 million metric tons. The main driver of the consumption is the electric power industry which accounts nearly the half of the total consumption; followed by cooling application with 15% and transportation with nearly 10%, see figure 1."

Jan 1, 2016

By B. K. Cantrell, K. L. Rubow

"The US Bureau of Mines and the University of Minnesota have developed design and performance criteria for a personal diesel exhaust aerosol sampler for underground coal mines. These are based on the premise that size can be used to separate diesel exhaust aerosol, which is mostly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. The sampler has three stages: a respirable aerosol preclassifier, a 0.8-um aerodynamic diameter inertial impactor to collect mineral dust and a final filter to collect the diesel aerosol. Using a sample flow rate of 2 L/min and gravimetric analysis to within 0.1 mg, the measure sub-0.8 um diesel aerosol has an a-priori limit of detection of 0.3 mg/m3.A miner working in an underground coal mine with diesel equipment is exposed to a wide array of pollutants from the diesel exhaust. These include CO, CO2. NO, NO2, SO2, diesel exhaust aerosol, and a variety of hydrocarbon compounds. A quantitative definition of the health risk resulting from these exposures remains elusive. During the past several years, though, progress has been made in defining the problem.Results from epidemiological studies by Garshick et al. (1988 ), animal inhalation studies by Mauderly eta). (1986), Iwai et al. (1986), and Brightwell et al. (1986) and in vitro studies by Lewtas et al. (1986) have provided sufficient data for the National Institute of Occupational Safety and Health (NOSH) to recommend that ""whole diesel exhaust be regarded as a 'potential occupational carcinogen,' as defined in the Cancer Policy of the Occupational Safety and Health Administration"" (NIOSH, 1988). NIOSH further stated that ""though the excess risk of cancer in diesel-exhaust-exposed workers has not been quantitatively estimated, it is logical to assume that reduction in exposure to diesel exhaust in the workplace would reduce the excess risk.""The Mine Safety and Health Administration (MSHA) has also been directed by an advisory committee to establish a diesel exhaust aerosol standard and to establish regulations to minimize exposure to diesel pollutants in underground coal mines (MSHA,1988). Both reports point out the need for development of measurement techniques for respirable diesel aerosol.In the past four years, the US Bureau of Mines (Cantrell,1987 and Cantrell, et al. 1987), in cooperation with Marple, et al. (1986), at the University of Minnesota's Particle TechnologyLaboratory (PTL), have studied the use of size-selective sampling techniques to measure the mass concentration of diesel aerosol in underground coal mines. Results from these studies have been used to develop design and performance criteria for a personal diesel exhaust aerosol sampler for use in underground coal mines.These criteria are based on the premise that size-selectivesampling techniques,can be used to separate diesel exhaust aerosol, which is predominantly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. In addition to the performance criteria, this paper discusses the laboratory and field test data used to develop the criteria."

Mar 1, 1992

By B. K. Cantrell, K. L. Rubow

The US Bureau of Mines and the University of Minnesota have developed design and performance criteria for a personal diesel exhaust aerosol sampler for underground coal mines. These are based on the premise that size can be used to separate diesel exhaust aerosol, which is mostly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. The sampler has three stages: a respirable aerosol preclassifier, a 0.8- µm aerodynamic diameter inertial impactor to collect mineral dust and a final filter to collect the diesel aerosol. Using a sample flow rate of 2 L/min and gravimetric analysis to within 0.1 mg, the measure sub-0.8 µm diesel aerosol has an a-priori limit of detection of 0.3 mg/m3.

Jan 1, 1992

By B. K. Cantrell

A miner working in an underground coal mine with diesel equipment is exposed to a wide array of pollutants from the diesel exhaust. These include CO, CO2, NO, NO2, SO2, diesel-exhaust aerosol, and a variety of hydrocarbon compounds. A quantitative definition of the health risk resulting from these exposures remains elusive, but during the past several years, progress has been made in defining the problem. Results from epidemiological studies by Garshick, et al. (1988); animal inhalation studies by Mauderly, et al. (1986); Iwai, et al. (1986); and Brightwell, et al. (1986); and in vitro studies by Lewtas, et al. (1986), have provided sufficient data for the National Institute of Occupational Safety and Health (NIOSH) to recommend that "whole diesel exhaust be regarded as a 'potential occupational carcinogen,' as defined in the Cancer Policy of the Occupational Safety and Health Administration," NIOSH (1988). NIOSH further stated that "though the excess risk of cancer in diesel-exhaust-exposed workers has not been quantitatively estimated, it is logical to assume that reduction in exposure to diesel exhaust in the workplace would reduce the excess risk."

Jan 1, 1990

By Santhanam Ramesh

"The shell (exoskeleton) waste of shellfish such as shrimps and crabs is the raw material in the extraction of chitosan, a polymer. Chitosan has several medicinal values such as reduction in cholesterol, urea and creatine in the blood. It is estimated that about 40000 tonnes of chitosan may be obtained from all chitin yielding invertebrate sources of India and a foreign exchange of 600 million US$ could be earned annually. Awareness has to be created among sea food processors to put up plants to convert shellfish wastes into chitosan. Similarly pharmaceutical industries may use chitosan in the development of new drugs. Types of training and awareness programmes to be organized for entrepreneurs, sea food processors and pharamacists are discussed in this paper.IntroductionIndia earns annually foreign exchange to the tune of 0.8 million US$ by exporting processed marine crustacean shellfish resources such as shrimps, crabs and lobsters (Figure 1) through 300 sea food processing industries. At present, only a small quantity of shell wastes (exoskeleton) generated from the above is utilized as an ingredient in fish feeds and hence much of the wastes are disposed off either as land fill or by direct dumping in sea. These wastes containing primarily chitin could be the major raw material for the production of a proteinaceous byproduct viz. chitosan, a highly valued pharmaceutically important source"

Jan 1, 2008