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By Z. R. Llanos

This paper presents a review of industrial and experimental processes for the recovery of molybdenum, vanadium, nickel, cobalt and aluminum from spent hydrotreating or hydrodesulfurization catalysts. Numerous processes have been developed in a laboratory and pilot scale. However, worldwide, there are only four well established commercial facilities currently in operation. The installed capacity of these facilities exceeds the availability of spent catalysts and may be sufficient to assimilate future increases of spent catalysts. Despite liability risks; significant quantities of spent catalysts are still being landfilled. Changing regulations that may affect the future handling and disposal of spent catalysts are also reviewed.

Jan 1, 1995

ARTHUR F. BRAID,* New. York, N. Y. (written discussion ?). -I have read Mr. Cain's paper with a very great deal of interest. The subject is one that is worth a great deal of thought and research at this time. It is a well-known fact that the strong affinity of steel or, iron for oxygen is perhaps the main detriment to sound production, and, as the author states, it is-indeed remarkable that today there are no analytical methods in general use in steel works for determining the gaseous con-stituents of steel.

Jan 10, 1919

By X. M. Prevost

A computer system to store, retrieve and process coal borehole and analytical data together with other geological, geographical or topographical information is described. As a result of the large volume and variety of data stored since its inception in 1979, as well as the basic versatility of the system, the National Coal Data Base has been performing a number of new tasks for which it was not originally designed. As considerable sets of data are used on almost every project, the use of statistical application programs has become an important processing tool.

Jan 1, 1987

By I. Iwasaki

Rest potential and linear potential sweep techniques were used to study the cathodic-polarization processes on chalcopyrite, simulating chalcopyrite short-circuited with grinding media in a wet grinding mill. Microflotation tests were carried out to investigate the effect of cathodic polarization on the collectorless flotation of chalcopyrite. It was observed that collectorless flotation of a cathodically polarized chalcopyrite sample could he obtained when oxygen was used for aeration, but not if nitrogen was used. A mechanism for the role that oxygen plays in the collectorless flotation of cathodically polarized chalcopyrite is discussed.

Jan 1, 1999

By Jay Smerekanicz, Florin: Pedersen Gheorghiu, Alan Cameron

In order to expand the capacity of Modern Landtill, a groundwater extraction system consisting of a linear system of pumping wells over 2,700 feet long had to be replaced. The new system would be covered by landtill cells to a depth of approximately 400 feet, and therefore would have to be maintenance free. In addition, the new system had to be proven to be more effective than the previous system, groundwater extraction had to be maintained during construction and construction could not disturb either the landfill operation or nearby residential neighbors.

Jan 1, 2001

By Steven T. Mitchell

The introduction of Vertical Crater Retreat (VCR) Stoping at the Homestake Mine in Lead, SD, constitutes a major advance in Homestake Mining Company's efforts to improve productivity and reduce costs through under- ground mine mechanization. The work to date indicates that Vertical Crater Retreat Stoping is one of the safest methods of underground hardrock mining today, and is competitive with all other forms of stoping in terms of cost and productivity. Homestake anticipates that VCR stoping will account for approximately 35% of the total mine production in 1981.

Jan 1, 1981

By Colin J. Booth

Hydrogeological impacts of active longwall mining were studied at two sites in Illinois. At the site with the more transmissive sandstone aquifer, aquifer permeabilities increased an order of magnitude due to subsidence. Piezometric levels declined with subsidence due to increased porosity, and ahead of mining due to a transmitted drawdown. Levels recovered rapidly at first and fully over two years. At the site with the less transmissive aquifer, impacts were similar except that recovery has been limited. Local aquifer enhancement through increased yield can occur, but only where the aquifer is transmissive enough for recovery.

Jan 1, 1986

By Neto J. A N

Usually there are organisational interfaces between each stage - companies or departments. Each organisation will have different ideas about "optimum" operation. These ideas will be driven by how the performance of each is measured ' and rewarded. Therefore it is important to set up data acquisition processes with respect to maximisation of overall profitability and resource utilisation. In the simplest case - if the miners are paid on tonnes and the concentrator has severe grade penalties on concentrates, then there is the possibility of a conflict of interest over metal Balance.

Jan 1, 1991

By Danny Riley, Brian Curry, Sandya Govindaraju, James Bain

Acute vibration causes vasoconstriction in naïve human subjects1. Vibration-induced decrease in skin perfusion has also been reported in the rat-tail vibration model 2. After vibration exposure, rat-tail arteries demonstrate vacuoles in smooth muscle cells, similar to that caused by pharmacological vasoconstrictors3. This study addressed the effects of different frequencies, durations and patterns of vibration on lumen size and vacuole formation using the rat-tail vibration model in male Sprague-Dawley rats (~300 g). Methods The different groups were: 4-hr continuous vibration at 30, 60, 120 and 800 Hz; continuous exposure durations of 5 min, 1 hr and 4 hr at 60 Hz; and 4-hr cumulative exposure of 60 Hz delivered intermittently in cycles of 10 min on and 5 min off. Acceleration was set at 49 m/s2 r.m.s. for all frequencies. Unanesthetized rats were restrained in cages on a nonvibrating platform with their tails placed on a vibrating stage driven by a B&K motor (4809). The sham control animals were also placed in the vibration apparatus but not vibrated. Room temperature was controlled at 25 ± 1°C. Ventral arteries from proximal tail segments 7 were immersion fixed in aldehydes, embedded in epon-araldite and sectioned (0.5 µm) for morphological analysis. Vascular lumen sizes were measured as the percent ratio of the lumen perimeter to internal elastic membrane length using Image J software (NIH). The number of vacuoles in the smooth muscle layer of each artery section was counted. Results Fig 1: Semithin sections of arteries. A. Sham control. B. 4-hr vibration 60 Hz. In vibrated arteries, the lumen decreases in size, and smooth muscle cells (SMC) exhibit vacuoles (arrow). Bar equals 40 µm for each panel. [ ]

Jan 6, 2006

By Dennis J. Appelhans

Lac Minerals Bullfrog conducted research and testwork to find an environmentally acceptable alternative to lead for fire assaying. The result of this work was the substitution of bismuth for lead in all fire assaying performed at the Bullfrog Mine. The environmental and economic ramifications of this discovery are highlighted.

Jan 1, 1993

By T. A. Wright

THE CHAIRMAN.- With your permission, I shall read for F. W. Willard, who is ill, the keynote paper of a symposium that, I hope, will make us all aware of post-war problems as well as of the present-day problems in the more efficient use of secondary metals.

Jan 1, 1943

By Guillermo Hileman

In March the President approved the new oil bill, .which became effective as Law No. 12161, providing among other things a contribution or tax on all producers varying from 8 to 12 per cent payable monthly. The new regulations, for chapter VI bearing on the tax feature, of this

Jan 1, 1936

By Guillermo Hileman

In March the President approved the new oil bill, .which became effective as Law No. 12161, providing among other things a contribution or tax on all producers varying from 8 to 12 per cent payable monthly. The new regulations, for chapter VI bearing on the tax feature, of this

Jan 1, 1936

By David Lilly, Robert Ethier, David Bremer

The Lafarge Ravena Cement Plant in Ravena, New York demonstrated continuous and extraordinary improvement in productivity during the past several years. The factors driving continuous improvement at the Lafarge Ravena Plant include: 1) Management techniques including regular scheduled and effective Blasting Optimization Team meetings. 2) A real time blasting database to guide blasting product and procedure decisions. Key decisions involved all levels of quarry and blasting supplier personnel and a close working relationship between production and blasting areas of expertise was demonstrated. 3) Blast optimization and optimization of quarry operating parameters such as blast location relative to crusher location, hours worked, etc.

Jan 1, 2007

By T. J. Fenner

Research conducted in South African mines has demonstrated the benefit of ground penetrating radar for the detection of geologic features and hazards. This is crucial for safety and production considerations in underground mines that are as much as 4 kilometers deep. This paper describes a new ground penetrating radar system designed specifically for high quality data acquisition, in the harsh conditions of deep underground environments, for use by operators with minimal geophysical experience. Design criteria included automated functions, intrinsic safety, light weight and minimal power requirements. Data is processed on the ground surface by geoscientists using a PC.

Jan 1, 1994

Evolutionary changes to the original sizer concept are mild when compared to those which have taken place in the engineering standards embodied in today's commercially available machines. This paper examines the principles of sizer operation and reviews the development trends in new applications for this unique screen type.

Jan 1, 1978

The characteristics and causes of the spoil pile failures at the Goonyella Mine are described, and research results from investigations of spoil pile instability are discussed. Some effects on spoil stability of the development of deep strip mining projects are considered and recommendations are made for relevant research.

Jan 1, 1981

By B. T. Dawson

In today's work world, constant changes are a fact of life. Downsizing and technological advances are two of the most prominent concerns for employers and employees alike. In this article, the author addresses some of the emotional consequences of these changes and offers a new, empowering perspective for coping with them.

Jan 1, 1998

Talk some about your background. Mining, particularly coal, runs in the family. I come from a mining family, one generation re-moved. Both of my grandfathers worked in the coal mines. My mother?s father had worked as a coal miner in the South Hills area of Pittsburgh after coming to America from Croatia. My father?s father (who died of black lung long before I was born) had been born in America and worked as a mine foreman and superintendent in mines just outside the Pittsburgh area. My father often talked about when, as a child, he accompanied his father underground on Sundays to check the mine pumps. While I never expected to go into mining, I often read some of my grandfather?s books on mining technology that my father had kept. I started college at Penn State and drifted into mining engineering as my third declared major. I was finally realizing the importance of a career choice. I?ve never regretted that decision. One of my children, Mark, has followed me into mining engineering, much to my surprise and pride. Evidently, he had been listening to the many conversations I had with friends and colleagues in the industry and never considered any other career path. He has since married another mining engineer, Kray Davis Luxbacher, so we truly have a mining family and can talk mining when we get together. My other children are in more mundane lines of work and rapidly tire of the mining discussions. I?ve worked for operating companies: Pittsburgh Coal Co. (then a division of Consolidation Coal Co., and a company I believe both of my grandfathers had worked for), Island Creek Coal Co., and a research organization: Occidental Research Corp. I am now with Glenn Springs Holdings Inc., dealing with legacy issues (primarily environmental) related to Occidental?s previous mining operations (coal and minerals). As such, I have a broad view of the industry and the critical changes that are shaping our industry.

Jan 1, 2008

In a future world of 8.5 billion people in 2035, the Energy Information Administration's (EIA) projected 50% increase in energy consumption will require true "all of the above" energy resource use from oil, gas, renewables, nuclear, and coal. In particular, coal will continue to be the world's energy cornerstone, providing more incremental energy over that same time period than any other single fuel. Coal has long been a centerpiece of a low-cost, high-reliability electricity grid. Today there are 1.3 billion people across the globe without access to electricity and 2.7 billion people who do not have clean cooking facilities. The problem is spread across the developing world, but it is particularly severe in sub-Saharan Africa and developing Asia, which together account for 95% of people in energy poverty. Without a commitment to achieve universal energy access it has been estimated that by 2030, there will be an additional 1.5 million premature deaths per year caused by household pollution from burning wood and dung and through a lack of access to clean water, basic sanitation and healthcare. Modern energy sources are essential to meeting these challenges.

Jan 1, 2012