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By J. F. Edwards

In situ extraction of copper through borehole injection presents a new technology for the mining of copper. For the successful application of this technology, copper recovery at the surface must be specifically designed for borehole injection and the general conditions of the well field. This paper describes the design of a solvent extraction / electrowinning facility specifically designed for in situ leaching of copper. This design is based on commercial solvent extraction / electro-winning with considerations of the requirements of this specific application.

Jan 1, 1988

By John C. Cook

There is pressing need for better means of exploring ground conditions ahead of mining. Exploration drilling has the drawbacks of high cost and a seriously restricted sampling zone. Traditional geophysical exploration methods including gravity, magnetic and resistivity techniques have been used with some success underground, but all give poor target delineation relative to range, since they depend upon minor distortions of a potential force field. Much greater ratios of resolution to range can, in principle, be obtained by employing electromagnetic or seismic radiation as the exploring agent. This is because propagation time delays can be used to measure range accurately, and to separate the small effect of a distant target from the much larger effects of nearer targets and of the transmitter. Seismic waves have long been used with great success in exploration for petroleum, and recent research on their application underground is promising. Electromagnetic (radar) waves have been very successfully used for detection and location through the air and outer space, and have also explored through polar icecaps more than a mile thick.l It is not generally realized that below the soil many rocks are also somewhat radar-transparent, and that radar can be used for exploring such rocks, once a quarry, a mine, a borehole, or other means of access has been opened. Radar waves are reflected by any boundary or object where they encounter a large change in electrical properties.2 The usual cause of such a change is a difference in moisture content. Radar waves passing

Jan 1, 1972

By A. K. Bakshi

Mineral suspensions show Newtonian flow properties at lower solid concentration, but change into non-Newtonian regime as the solids content is increased. For Newtonian fluids viscosity is independent of shear rate, but for non-Newtonian fluids it varies with rate of shear. Therefore, measurement of viscosity at a shear rate, different from the process will be futile unless the slurry is Newtonian. This is especially true for hydrocyclone operation, where the rate of shear is different at different points within the hydrocyclone. In this case, it is very important to determine the flow type of the suspension before attempting to establish any correlation between viscosity and process efficiency. A new technique to distinguish such changes in flow type has been developed. This involved a co-axial cylinder type viscometer which measured apparent viscosity at a low shear rate, and a vibrating sphere type viscometer which measured the apparent viscosity at a high shear rate. Special precautions were taken to allow measurements of viscosity of rapidly settling mineral suspensions. Because the vibrating sphere viscometer operated at a much higher shear rate than the rotating viscometer, the two instruments together could determine the shear-rate dependency of the viscosity. Ground silica of 80% passing 65~m size in water was used to prepare slurries at concentrations ranging from 1O-70wt% solids. Viscosity of each slurry sample was measured simultaneously by both the viscometers and the results were compared with each other. With this technique, it was found that all the silica slurry samples were in the Newtonian flow regime.

Jan 1, 1995

By W. M. Shaver, R. Letourneau, W. R. Dengler

Dynatec Mining Limited contracted to sink a 1500 metre (4960 ft.) concrete lined shaft for Falconbridge Nickel Mines in Sudbury, Ontario, Canada. The shaft is 6.3 metres (20.5 ft) in diameter inside the concrete lining and is equipped with steel furnishings. Dynatec used the owner supplied 4.6 metre (15 ft.) diameter double-drum hoist to sink the shaft with 12.5 tonne buckets for muck removal and 4 cubic metre concrete buckets for concrete placement. One of the unique features of the shaft sinking operation is the use of a four-boom electric hydraulic drill jumbo permanently mounted in the shaft sinking stage. This paper will describe the performance obtained with the electric hydraulic drilling equipment and the high capacity muck removal and concreting equipment.

Jan 1, 1991

By Emily Wortman-Wunder

Attendees at December?s Arizona SME Section Conference at the Hilton El Conquistador Resort outside of Tucson, AZ were feeling optimistic and ready to get to work after a year of steady growth and recovery in the mining industry. During the two-day event (Dec. 5-6, 2010) and the preceding American Mining Hall of Fame banquet and awards ceremony, the focus was on copper, worldwide population growth and regulatory pressures, with several smart new projects featured alongside updates to traditional large-scale copper development projects. Keynote speaker Timothy Snider, chair of the University of Arizona?s Lowell Institute for Mineral Resources, hit the mood of cautious optimism when he analyzed the global demand for resources, using the case example of copper. Over the next 20 years, he said, the world?s population is expected to grow to 9.2 billion and the average annual per capita copper use is expected to rise from 2.2 to 4.5 kg (5 to 10 lb). The increase in demand will provide tremendous opportunity for mining companies, he said, but cautioned that the opportunities are balanced by negative influences on demand and pressures on supply. While demand for copper is currently growing, Snider noted that there were significant downward pressures on demand as well. These included a western world that is overbuilt, in-creasing use of substitute materials in new construction and the rise of wireless devices. He also noted new regulatory pressures, and pointed out that resource development now had to occur within a context of sustainability on several levels.

Jan 1, 2011

By W. J. Karwoski

A ground-support system for grizzly and haulage drifts was tested in Magma Copper Co.'s San Manuel mine. Eight two-piece, wide- flange steel sets were erected in a ventilation drift on the 2315 grizzly level. The sets were lagged with three different materials and back- packed with pea gravel and sand. The pillar on either side of the drift support system was instrumented with stressmeters and rock-bolt load cells, the backfill with pressure cells, and the steel sets with load cells. Results indicate a better survival rate than with typical monolithic concrete.

Jan 1, 1979

By Leonard Sugin

As we approach the end-of the 20th century we are made more aware of the tremendous role that energy plays both directly and indirectly in our varied way of life. The industralized nations of the world have already established industries and economies which are greatly dependent upon the availability of energy. The underdeveloped and developing nations of the world are slowly and surely moving to the same utlimate requirements. The world wide need for distribution of energy sources is continuing to grow. At the present time there is a great imbalance between the sources of energy and the consuming economies In order to bring about greater equality between supply and demand major efforts and large capital expenditures are constantly being made. Industralized areas are seeking their own independent sources of energy whereas those areas of the world which contain great reserves of energy are limiting its export as well as developing its own industralized capacity. Nevertheless, energy bearing materials are still transported great distances in order to satiate the appetites of power hungry economies.

Jan 1, 1975

By H. A. Stoess

The Minerals Industry makes heavy demands for and on its Material Handling equipment. It also gives progressive management the opportunity for considerable savings, ad consequently increased profits. In some cases, cost of Materials Handling amounts to 40°/o of the total cost of the ultimate product. Handling costs are hidden in overhead, indirect labor, excessive maintenance, productive workers performing handling tasks, and, a great many more. Even though Materials Handling is the oldest occupation of mankind, it is only within the past twenty years that it has emerged as a specialized field. While this industry has made full use of all types of mechanical and vibratory conveyors, pneumatic conveyors in their proper application can be a distinct asset. me use of pneumatic conveyors by this industry however is limited- to a certain extent by the particle size of your products through the various phases of manufacture, as well as their bulk density. However, with increasing knowledge of the fluidization of dry materials, their use is becoming more wide spread.

Jan 1, 1962

By F. Dudouit, M. M. Mohkam, F. Renault

The Pannerdensch Kanaal Tunnel is part of Holland’s Betuweroute high speed freight railway project linking Rotterdam to inland of Europe. It comprises of twin tunnels, 1620 m long each, with 8.6 m inner diameter. The Tunnel alignment is situated mainly in sandy formations and under high hydrostatique pressure. The over burden cover varies from relatively high to very low, sometimes much smaller than the diameter. One of the special features of the Pannerdensch Kanaal Tunnel is that, over some 250 m, the twin tunnels are to be bored in a back?lled sandpit. Some 490 000cubic meter of sand has been placed and compacted by vibro-?otation to refill the sandpit. The tunneling machine is a 9.8 m slurry shield manufactured by Herrenknecht. Tunnel lining is precast concrete consisting of seven plus one key universal segments. Other than the special feature of boring through re?lled sand, constraints such a slow overburden while crossing under Pannerdensch Kanaal and some lagoons, as well as high liquifaction potential of sandy formations, render this job very unique of the type. Fine studies were conducted in heading’s stability. And, confinement pressures were determined considering different risks of liquefaction and blowout problems. Both tubes have been successfully bored. Several sections have been monitored. The results are quite interesting and in accordance with contract technical conditions.

Jan 1, 2003

By Elmer R. Drevdahl

During the last few years there has been a rapid increase in the development of the community or junior college throughout the United States, Some factors behind this development include the need for more college facilities to service the growing number of high school graduates, the desire of the public to provide some post high school education at reasonable costs, and the need to provide post high school educational opportunities not now provided by most of the universities and colleges. Many of the new community colleges provide at least three educational services including local opportunity to provide the first two years of a four year college program, two year technical-vocational programs of a terminal nature, and adult educational opportunities. The community college has the advantage of not being saddled with years of academic tradition which prevent it from changing to suit the educational needs of the community It serves. The flexibility of the community college in developing new programs, particularly in the technical areas, is going to provide industry with many of the badly needed technicians it is now unable to secure.

Jan 1, 1965

By Pramod C. Thakur

Floor gas emissions on wide longwall faces are common occurrences in the Northern and Central Appalachian basins. It creates unsafe working conditions on the face and results in very costly production delays. This paper discusses various methods of mitigating the floor gas emissions including hydrofracing of underlying strata, use of cross-measure boreholes and specifically completed gob wells.

Jan 1, 2005

By Barbara C. Schickner

No group has been harder hit by the problems confronting the coal mining industry than small, independent surface mine operators in the eastern US. Burdened by costly government regulations, major capital shortages, declining productivity, high unemployment, and idle and closed mines, many in the industry think the breed will not be able to survive much longer. But there are a few sole owners fighting to remain independent-and succeeding. John Wagner is running a coal stripping operation in northwest Pennsylvania on a unique blend of aggressive management and marketing, support from a team of blue-chip professionals, and some unusual tactics. Though Wagner's approach is hardly an across-the-board formula for survival-he is currently reorganizing under Chapter 11 of the Bankruptcy Reform Act-a look at his operation helps illustrate some of the unique problems confronting eastern surface miners.

Jan 2, 1980

By Waldo Valderrama, Luis Magne, Paola Grandela

The effect of liner shape on power consumption was studied in a small laboratory mill under various operating conditions. It was found that the angle subtended between the lifter front face and the face in contact with the mill case has the most significant influence. The increasing height of lifter reduced power consumption, whereas the lifter spacing did not show any influence. The effect of height is less relevant at lower front angles. Highest power consumption is achieved with a 45" front angle. A comparison of cylinders and balls under identical conditions gives higher power consumption for ball charges. The data does suggest that, for maximum power draw, slip in the outer layers of the charge and the early recirculation of energy to the mill case should be avoided. Both factors prevent an efficient energy transfer to the mill charge.

Jan 1, 1995

By R. R. Oder

Reported are weight, particle size, gross chemistry and magnetism measurements for lithic, mineral and fused soil components separated from five lunar soils using dry, open-gradient, magnetic separation. Pure diamagnetic anorthite, a feedstock for the electrochemical separation of oxygen and metals, has been separated from anorthistic highland soils. In addition, paramagnetic ilmenite has been separated from high-titanium, basaltic mare soils. Ilmenite, a feedstock for oxygen preparation by hydrogen reduction, may also serve as a source of He3 for use in fusion power generation. Agglutinates (vesicular, glassy components containing metallic iron) have been separated from all of the soils. Iron and refractories can be used for space construction. Metallic iron is easily detected in lunar soils by magnetic susceptibility measurements. Based on the exploratory laboratory results, conceptualizations of innovative magnets for processing lunar soils are presented.

Jan 1, 1993

By Osvaldo Bascur

Large metallurgical complexes have more data than a small city and much of it is "real time," changing rapidly as internal and external conditions evolve. As corporations buy and sell assets and reengineer their staff, the structures and tools that were used to understand these data are lost. This results in significant deterioration in the ability to maintain a "smart" operation. The solution is to use the sophisticated new tools built for the Internet so as to leverage information in a familiar browser format that people can use and understand. This paper describes the use of Internet technologies with plant data. Examples are drawn from existing industrial sites. Users must project where this technology will lead - standing still is the most dangerous philosophy and the only one guaranteed to be obsolete. These examples show the way to leverage existing workers with information technology.

Jan 1, 2000

By James Crosby

The Urad property had been worked intermittently for over 50 years before American Metal Climax (AMAX) started an extensive exploration program on this property in 1961. The detailed studies of the property proved a large ore body of low grade molybdenum ore that could be mined by modified panel caving methods. Mine development and mill construction for a 5000 TPD operation was completed in July 1967. The Urad mine and plant site is located 55 miles west of Denver near Berthoud Pass. The plant elevation is 10,200 feet. The crushing plant is located underground because available surface area is re¬stricted by snow slide hazards. Crushing plant layout and ventilation system design for the Urad mine was based on our operating experience at similar crushing facilities located at the Climax operations. Low speed conveyors of generous width, adequate exhaust volumes at all ore transfer locations, large hoods and good conveyor skirting have made the Urad underground crusher dust control operations very satisfactory. Good maintenance and cleanup of the crusher facilities have made a clean working area with very low dust exposure. The ore from the mine is dropped approximately 1000 feet through ore passes to scraping drifts above the crusher and then transferred to the coarse ore bin by 150 h.p. slusher hoists. A reciprocating plate feeder under the coarse ore bin feeds a 48 x 60 jaw crusher. Ore from under the crusher is conveyed on a 48 in. belt to a vibrating screen where oversize passes through a 7 ft. Standard cone crusher. The crushed ore along with the screen undersize is conveyed on a 42 in. belt to a 1000 ton surge bin.

Jan 1, 1971

By G. P. Richards

RIP is the process of recovering uranium from an unclarified slime pulp which comes in contact with a moving bed of ion exchange resin, T e sand-slime separation of the acid-leach slurry is accomplished through the use of cyclones and spiral, akins type classifiers. Course sands are discarded to tailings and the combined slimes and leach liquor become the IX feed. Uranium in the IX feed is absorbed on the resin and after exhaustion the barren pulp is directed to tails, Following the uranium exhaustion cycle an eluant solution passes through the resin bed stripping the uranium from the beads, The uranium is precipitated from the clarified pregnant eluant, filtered, dried and packaged for shipment to the AEC, Normally, the ore received at the Mines Development plant is a loosely cemented sandstone containing small quantities of clay and bentonite, The ore is easily crushed and requires only a 1/3 load of rods in the rod mill to reduce the ore to grain size, Very little of the ore is recirculated by the 42" spiral classifier.

Jan 1, 1958

By Frank F. Roxborough

The paper presents a brief account of the principal findings and an assessment of the practical value of a substantial international research effort into the mechanical excavation of rock that has been in progress over the past 30 years. This assessment together with an appreciation of the emerging trends in mechanical excavation suggests what are likely to be profitable lines of future inquiry.

Jan 1, 1985

By Rudolf E. Greuer

Modeling a mine ventilation system is a formidable mathematical problem requiring the solution of twice as many equations as there are airways with half of these being quadratic equations. The addition of a mine fire to the problem adds many more complexities. The U.S. Bureau of Mines and Michigan Technological University attacked this problem in stages. During the 1970's and 80's, a series of computer simulation programs were developed which offered progressively increasing levels of modeling capability and accuracy. The current version of this software, MFIRE 2.0, was released in 1993. This programs provides for full dynamic state mass flow-based modeling of a mine ventilation system, and includes natural ventilation, mechanical ventilation, air reversals and recirculation, methane and fire contaminant spread, and moisture condensation and evaporation in the mass flow and heat exchange calculations. This program is a useful tool for routine ventilation planning and can significantly improve mine safety by enabling detailed quantitative analysis for mine emergency preplanning. This paper reviews the evolution of the MFIRE program from its infancy as a simple digital network simulator replacing analog computers to the present version.

Jan 1, 1994

By Terry R. Guilinger

A minitest of the new potassium chloride-potassium carbonate two-stage in situ uranium leach process has been carried out at the Intercontinental Energy Corporation (IEC) Zamzow project site in South Texas. Substantial quantities of high concentration uranium were produced indicating the viability of the leach solution. The test results yield information regarding the reservoir dispersivity, the average cation-exchange capacity of the formation, and the distribution coefficients describing carion-exchange reactions. The test a1 so indicates permeability anisotropy and the existence of disturbed flow fields. The research was partially funded by the U.S. Bureau of Mines.

Jan 1, 1984