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Segregation roasting tests were carried out on Zaire cobalt oxide ores assaying about 2% Co and 3.5 to 6.5% Cu. The major parameters tested during the laboratory investigations were temperature, dosage and type of reducing agent, dosage and type of chloridizing agent, and particle size. Results showed that standard conditions suited to the segregation of copper ores, i.e. low temperature and low dosages of reducing and chloridizing agents, resulted in the segregation of copper only, while conditions suited to the segregation of lateritic nickel, i.e. higher temperature and increased dosages of reducing and chloridizing agents, led to a successful segregation of both copper and cobalt. Under the best conditions, 88% of the cobalt and 98% of the copper could be recovered in a concentrate assaying 32.5% Cu and 8.5% Co. Alternatives to process such a concentrate are briefly reviewed.

Jan 1, 1993

By Alan J. Michaels

The paper addresses the problem of the high costs of accidents ad how AMAX Inc. - a diversified natural resources company - has managed to control its losses through a tri-thrusted approach of: (1) management commitment, (2) methods of implementation that are tailored to each division or local unit, and (3) a reward system for outstanding performance. Specific attention is focused on the Corporate Loss Prevention Department's "10 Point Program for Loss Prevention Management".

Jan 1, 1981

By Earl R. White

In 1950 Kaiser Steel Corporation acquired control of the Utah Fuel Company, a pioneer Utah coal concern owning large reserves of high volatile coking coal near Sunnyside, Utah. The mines at Sunnyside have been producing high quality coking coal since the late 1890's. Kaiser Steel acquired the coal deposits at Sunnyside in order to supply the necessary coke for its steel plant at Fontana, California. The Sunnyside coal deposits are made up of two mineable beds, the upper and lower Sunnyside seams. Both seams outcrop along the southward facing escarpment of the Book Cliffs. The coal seams dip under the massive sandstones of the Book Cliffs to the northeast at 5 to 22 pct., with the steepest-part being near the outcrop. Mining at Sunnyside up to 1961 had been carried on with room and pillar methods. The deep cover and rotten roof conditions, along with the need of increased tonnage, required a change of mining technique. Numerous ideas were presented, discussed, and economically analyzed. Several people involved in these discussions, with the aid of W.W. II, had been introduced to the European methods of coal mining, namely the longwall technique. The European mines had long been plagued with near similar conditions as those at Sunnyside, particularly the deep cover problem. The longwall method seemed to be working very well under these conditions, and with the extensive studies given longwalling by the Kaiser Steel mining officials, it was decided to give longwalling a try.

Jan 1, 1976

By B. Numerov

A numerical proceeding of corrections with respect to topography is worked out for places near the station and a graphical one for the remote parts of the terrain. The description is clear and very detailed. The numerical proceeding is very similar to that of the Eötvös and Schweydar methods which are in use already. In both methods the levelling is accomplished in certain circles and fixed azimuths around the station. While, in using the Eötvös method, the height differences are directly inserted into the final formulas with regard to the foot of the instrument and in case of accurate formulas derived by Schweydar the height differences are calculated with respect to the center of gravity of the attachment, Numerov introduces functions A and B, the heights, of the terrain and of the center of gravity, which are to be inserted into the formulas.

Jan 1, 1929

By Colin Lawrence

The Port of New York and New Jersey is one of the most heavily used transportation arteries in the world, handling nearly 40 per-cent of the North Atlantic shipping trade and directly providing nearly 230,000 jobs to the local economy. In 2004, $100 billion worth of consumer goods moved through the port. To accommodate future cargo volumes in the port, which are expected to double over the next decade and possibly quadruple in 40 years, deeper shipping channels are needed to provide access for a new generation of cargo mega-ships with drafts exceeding 13.7-m (45-ft) when loaded. Current channels within the harbor range in depths up to 13.7-m (45-ft), thus preventing carriers from using these larger ships, or requiring significant reductions in cargo to achieve lesser drafts to operate safely within the harbor. As part of the Harbor Deepening Project, the Anchor-age Channel would be deepened to 15.2 m (50 ft) below mean low water (MLW), for a length of 5,790 m (19,000 ft). The New York City Department of Environmental Protection (NYCDEP) owns, operates and maintains two existing water siphons in the harbor. Due to their shallow depth, both existing siphons must be relocated before dredging of the Anchorage Channel can be completed. Tom Costanzo, manager of capital programs for the Port Authority of New York and New Jersey (PANYNJ), says that ?While the re-location of the existing siphons under the Anchorage Channel is vital to the success of the deepening program, it is also a story of cooperation among key agencies at different levels of government resulting in improvements that will benefit the people of this region greatly.?

Jun 1, 2010

By Peter Johnson, David Barber, Lachlan Henderson

"Within underground portions of metro rail networks the traditional approach to a design fire has been to assume a worst credible railcar fire and develop ventilation and egress measures for life safety. This approach is being challenged as a rail network approach to design fires becomes a more practical and realistic approach. The network approach is based on utilizing an in-depth hazard analysis, to understand ignition and fire load sources in tunnels, above and below the floor of the railcar and within stations, and then utilizing a quantitative risk assessment to determine sets of fire scenarios. The process allows small, medium and large fires to be considered, with the consequences also being quantified. The selection of design fires has a significant influence on fire protection measures within a metro network and hence, is a major cost input. The rail network approach provides more robust decisions on fires, based on the hazards present. INTRODUCTION A fire within a rail car or one that occurs as part of a rail system can threaten the lives of users, maintenance staff and emergency services personnel. Fires in metro systems are rare events but can have severe consequences. As a result, any analysis of a potential fire must be thorough and rigorous and address not only regular accidents and small fires, but also very low probability, high consequence scenarios. The fire safety design process for a tunnel and station must start with the design engineers, contractor and operators making a number of key decisions related to fire protection measures, which may have significant cost considerations. One of the key aspects that influences the required fire protection is the design fire and the design fire scenarios, which is a key input for analysis. This paper provides an overview of the author’s experience in designing fire protection measures for rail networks in Europe, Australia and NZ, where a risk based framework is used to develop design fires and scenarios for the whole rail system – trains, stations and tunnels. This system wide approach is innovative, challenges the norms, but provides significantly more informed outcomes. The range of design fires will include small fires that may halt the network, larger fires for smoke hazard system design and significant post-flashover fires to assess the structural response."

Jan 1, 2016

By John J. Sammarco

This report details the testing and evaluation of a modular azimuth and positioning system (MAPS) to provide navigational information for a continuous mining machine. Vehicle navigation is part of the U.S. Bureau of Mines research program in computer-assisted mining serving as a tool to increase mining health, safety, and productivity. The Bureau is investigating other navigation systems, but MAPS seems to have the most promise. MAPS was installed on a continuous mining machine. An operator used the machine to cut coal while researchers collected machine and MAPS data. A comparison of MAPS data for xy position and data obtained with an electronic transit showed an increasing error for MAPS. After 30 min of operation, the easting position error was -0.02 m, and the northing position error was 0.019 m; after 60 min of operation, the easting position error was -0.19 m, and the northing position error was -0.26 m. Modifications to MAPS software and to the operational procedure of the machine significantly reduced this error by a factor of 3.7. Researchers continue to reduce these errors.

Jan 1, 1993

By J, T C. McCuaig, J Hodgkison, T Fouet

Olympic Dam is the eighth largest Cu deposit and the largest U deposit in the world, with approximately 35 million tonnes of contained Cu and 1.2 million tonnes of U. The most recent resource estimate was for 2.95 billion tonnes of mineralised material with average grades of 1.2 per cent Cu, 0.4 kg/t U, 0.5 g/t Au, 2.6 g/t Ag as contained mineral resources. Olympic Dam is expected to produce >200 000 tonnes of Cu and 4200 tonnes of U3O8 from 9.8 million tonnes of ore in 2004, making it the 12th largest Cu producer in the world. One of the impediments to achieving targeted rates of production has been oversize material (>0.9 m) reporting to stope draw points. A major contributor to oversize material may be overbreak along pre-existing structural weaknesses from stope walls and backs during the production life of a stope. Underbreaking to structures can also have a detrimental effect on the performance of a stope. In an effort to understand the influence of structural geology on stope performance, WMC Resources and SRK Consulting partnered during 2003 to refine the current system of structural mapping, and to use historical data to produce a structural interpretation covering a large part of the mining area. The interpretation has been wireframed in DATAMINETM into a three-dimensional structural framework model. To date, there are more than 600 structures of >50 m strike length incorporated into the structural framework model, which covers a study area 1500 m + 600 m + 350 m. A back-analysis exercise to assess the influence of interpreted structures on overbreak and underbreak was completed for laser-surveyed stopes.

Jan 1, 2004

By N. V. Mel'nikov

This paper discusses the reserves of oil, natural gas and coal in the USSR, with particular attention to the future role to be played by coal in supplying the energy fuel resources of the country.

Jan 1, 1972

This article takes the OMRON C200HE PLC for example introducing its application in mica-paper production equipment, including style selection, address assignment of I/O point, and programming for different function. In the transformation process of simulated data and digit data, the corresponding relations between two data and so on are also discussed.

Jan 1, 2014

By C. S. Ha, H. S. Choi, D. Y. Shin

POSCO installed a new 100 ton oxygen bottom-blown converter in 2013 for the development of new steelmaking process named as PS-BOP which is reading POSCO-Saarstahl Basic Oxygen Process. This process was developed by the collaboration research between POSCO and Saarstahl AG in Germany that is based on substantial increase of CO post combustion in a converter by blowing hot air from the top of converter. The collaboration research has been finished successfully in November 2013 with 17% decrease in hot metal ratio (HMR) when hot air was blown from the top of the oxygen bottom-blown converter. After the collaboration research the converter has been tried to be operated as oxygen top and bottom-blown converter to reduce bottom wear and to decrease production cost with increased use of low cost Fe source by the help of increased CO post combustion. The presentation includes experience on the start up of oxygen bottom-blown converter, HMR reduction trials with hot air top blowing and transition from oxygen bottom-blown to top and bottom-blown converter operation.

Jan 1, 2015

By Lon Santis

This paper analyzes 110 serious accidents that occurred during the use of commercial explosives in mining, construction, and other industries since 1992. Data from the Mine Safety and Health Administration (MSHA), the Institute of Makers of Explosives (IME) members’ reports, and media reports were used. Only accidents that resulted in a fatality, significant lost work time, or injury to the public were considered in this analysis. The accident data were analyzed for trends in frequency, type of industry, cause, type of individual harmed, and geographical region. Although the data showed that explosives accidents are decreasing in frequency, still, 29 people were killed and 134 injured. Eightyfive of the accidents occurred in mining, 17 occurred in construction, and 8 occurred in other industries including oil recovery, seismic exploration, agriculture, logging, boiler cleaning, and avalanche blasting. As other studies have shown, flyrock and failure of blast area security caused over half of the accidents. Mishandling, misfires, or fumes caused just over one-third of the accidents. Lightning and drilling into explosives were responsible for the remainder of accidents.

Jan 1, 2003

By J. M. Somers

Methane is a powerful greenhouse gas and the principal component of natural gas. Coal seams often contain significant quantities of methane, and underground coal mines must ensure that methane released into the mine during coal extraction does not build to dangerous levels. This is accomplished in part through the use of large-volume ventilation systems that remove methane from the mine and release it to the atmosphere. Although the methane concentration exhausted is quite low (typically <1 percent), the volume of air that ventilation systems move is so great that they actually constitute the largest source of methane emissions from underground coal mines. Each year underground coal mines throughout the world emit more than 500 billion cubic feet of methane from their ventilation systems. An air pollution control technology, thermal oxidation using a flow-reversal reactor (TFRR), has emerged as a potential solution to ventilation air methane (VAM) emission mitigation. One manufacturer of TFRRs has demonstrated its oxidizer design (the VOCSIDIZER?) at coal mines in the United Kingdom and Australia. These demonstrations tested the technology?s effectiveness at oxidizing low-concentration methane, as well as its ability to tap the excess heat to produce steam for electric power generation. In early 2007, the first U.S. demonstration of this technology began operation at an abandoned mine in West Virginia. The project is designed to prove the technology?s operational robustness, its ability to reliably oxidize methane at concentrations typical of mine exhausts, and its safety. If the technology is employed at active underground coal mines, it offers the potential to mitigate substantial quantities of global methane emissions. This paper discusses global VAM emissions, options for the recovery and utilization of VAM, and existing projects such as WestVAMP in Australia and the ongoing U.S. VAM demonstration project.

Jan 1, 2009

By Hormando Leocadio, CWM van der Geld, Julio Cesar Passos

Impinging water jets promote high heat flux extraction rate. Steel industry widely employs the process for accurate temperature control to improve the microstructure and to ensure adequate mechanical properties. The range of surface temperatures, heat fluxes and cooling rates are very large, which makes it important to obtain an accurate value of the heat transfer coefficient. This paper presents an experimental and numerical study of the heat transfer behavior of a high temperature (450°C - 900°C) steel plate cooled by a water jet at 20°C to 70°C. High-speed imaging (up to 20,000 fps) within water jet impingement zone allowed the characterization of the boiling regimes in the early stages of cooling. The effects of initial temperature, water jet temperature and velocity on the heat transfer coefficient were analyzed by inverse heat conduction method that predicts the heat flux and temperature on the top surface from temperatures measured with thermocouples inserted in test plate. Heat transfer is strongly affected by the initial temperature of the hot steel, water jet temperature and, less intensely, by jet velocity. High cooling rates start when liquid water is in direct contact with surface temperatures above 700°C.The results will contribute to the enhancement of the temperature cooling control on the runout table and cooling model employed at Usiminas Hot Strip Mill.

Oct 1, 2019

By G. J. G. Juby

The Chamber of Mines Research Organization has been evaluating three membrane-desalination processes for use within the South African mining industry. These processes are electrodialysis reversal (EDR), tubular reverse osmosis (IRO), and slurry precipitation and recycle reverse osmosis (SPARRO). The evaluation of EDR and TRO is complete, and the operating costs (1988) associated with each process are expected to be about 50 cents per kilolitre for a plant of 50 l/s (4 Ml/d) installed capacity. The SPARRO process is still being evaluated. Pilot plant results, water Qualities, and expected capital costs are presented where appropriate.

Jan 1, 1992

By J. E. Chilton

The Bureau of Mines has examined the operation of an oxygen sensor manufactured by the City University, London, England. The sensor produces a current proportional to the oxygen concentration by reacting oxygen at a nonconsumable cathode. The sensor design is unique in that the primary mode of oxygen transport to the cathode is by diffusion through a capillary, The sensor using this design has a stability of 0- to 0.02-pct reading change per day over a 4.7-month test, small temperature coefficient of 0.29-pct reading change per °C, and small pressure coefficient of 0.34-pct reading change per 1,000-ft altitude change, If this sensor were incorporated into an oxygen detector or monitor, this would be a distinct improvement in electrochemical-type oxygen analyzers and would be useful to the mining industry.

Jan 1, 1983

By Seanley C. Suboleski

This paper examines the likely productivity improvements that have resulted from the introduction of technological advances in underground coal mining during the decade from 1977 to 1987. Included in these advances are the changes in longwall mining; the introduction of larger, more reliable, more repairable continuous miners and shuttle cars; the introduction of remote control and flooded-bed scrubbers; supersections; and other improvements. Procedural improvements are also examined and quantified, the unexplained gains in productivity are attributed to??other factors", among them an increasing maturity of the work force, stabilization of the mining laws, increased labor-management co-operation, and economic urgency.

Jan 1, 1990

By John C. Hartley

Three systems that monitor ventilating fans are described. These electronic monitoring systems automatically perform most of the operations required to conform with the provisions of the Federal Mine Safety Code in the event of fan failure or slowdown.

Jan 1, 1964

By D. G. Mason

During the design of copper refinery tankhouses, there is a need to develop mass balance calculations for many process components, so that optimum physical plant configuration is achieved. Each mass balance is complex, possibly with over 120 interactive variables as basic input data. Recent developments in tankhouse design (e.g. permanent cathodes) have greatly increased the design options available for any project, multiplying even further the requirement for calculations. In the past these calculations were tedious and susceptible to human error. A comprehensive computer program can now simplify the task of the process metallurgist, enabling more sophisticated and sensitive plant designs to be produced. The paper describes the successful development of a flexible mass balance program that originallly was used in a feasibility study which had to be completed within a short time schedule. The program has been further developed and used for design and energy calculations; it can be usefully applied to existing plants to assess the impact of variations in operating parameters. The software takes account of staged liberation, electrolyte purification bleed and generates a reliable process inventory listing: it can also cope with stripper starting sheet options and disparate commercial circuits.

Jan 1, 1987

From a distance, the 0.75-km (0.5-mile) rail line that sits in the shadows of Vale-Inco?s Stobie Mine outside of Sudbury, Ontario could be mistaken for a standard conveyor belt hauling ore from the nearby mine. But with its large, yellow-painted loop and interconnected green rail cars that invert themselves on the loop before correcting with a smooth rollover further down the track, one might assume that this is some sort of test track for a new roller coaster. The fact of the matter is that it is the proving ground for Rail-Veyor technology, a technology that the company hopes will one day change the face of ore transportation in surface and underground mines around the world. With a line of linked, low-profile rail cars that are capable of carrying up to 1 t (1.1 st) per car of ore by way of simple, above ground, lightweight rail track, the technology is not groundbreaking. In fact, it was developed in the 1960s for the French State Railroad. A demonstration plant for the Florida Institute of Phosphate Research was installed in 2000 and the first commercial under-ground installation was in 2007 in South Africa at Harmony Gold?s Phakisa Mine. There, a 4.7-km- (2.9-mile-) long tram between two shafts operates three Rail-Veyor trains on a shared track. The difference is that the application that is being tested day-and-night in Sudbury is getting closer to wide production, thanks to the use of computer controlled automation that has helped turn an old idea into a cost-effective modern solution.

Jan 1, 2010