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The response of 174 domestic water supplies to longwall mining of the Pittsburgh coal seam was compared to various physical parameters. Sixty-four percent of domestic water supplies returned to service without the need for intervention, while thirty six percent required intervention to reestablish a suitable water supply. Domestic well response is strongly correlated with the topographic setting. Valley wells showed the least effect while hilltop wells showed the greatest effect. Well response was also found to be correlated to the location of the well above the mining with greater effects observed in zones of surface tension and compression, and fewer effects in zones which are stress neutral. Ground water supplies remained unaffected or were re¬established at 149 of 150 sites, indicating that ground water resources remain available to domestic wells after mining. Results of this study support the stress-relief model of ground water flow in the Northern Appalachian Basin. Longwall mining's effect on this system is to locally increase fracture connectivity in the near surface zone. This may shift the zones of saturated fractures to greater depths beneath hilltops and hillsides, and increase recharge and storage in valleys. General trends in well response are predict¬able utilizing the stress relief conceptual model, the topographic setting of the water sources, and their location over the mine.

Jan 1, 1986

By Z. T. Bieniawski, Christopher Mark

A new method for the design of long- wall chain pillars, called Analysis of Longwall Pillar Stability (ALPS), is described. The method provides estimates of the relative stability of different longwall pillar designs during all stages of their service life. The key issue addressed by ALPS is the magnitude and time-of-arrival of the longwall abutment loads applied to chain pillars. A field study was conducted and other available field data were analyzed in order to develop an approach for estimating the abutment loads. An example based on longwall experience in the Pittsburgh seam is used to illustrate how ALPS can be used in mine design.

Jan 1, 1986

By A. Redfern, B. G. D. Smart

The ultimate objective of the development work presented in the paper is to devise an appropriate method for relating powered support specification to geological conditions and mining practice, thus enabling the longwall method of coalmining to be successfully implemented throughout the varied coalfields of the world. The paper begins with a review of various methods previously used to determine support rating, each method being analysed with regard to its source, the logic and theory which constitute the method, and subsequent recommendations. An alternative approach is then proposed, the Powered supports being considered to be one of three foundations, sharing load with coal ahead of the faceline which acts as another foundation, and the waste behind the supports which acts as the remaining foundation. The load/deflection characteristics of the coal and waste, which in turn are related to geological conditions and mining practice, are shown to affect the load transfer on to and hence the specification of the powered support. In particular the characteristic of the waste foundation is shown to be affected by the caving mechanism, an alternative form to that mechanism accepted for British conditions being proposed and designated "parting-plane-controlled" caving. A finite element solution for a beam on elastic foundations was used to translate the above concepts into numerical results, these results being compared with data from Indian and Chinese operating conditions. The Indian case study examines the effect of using a conventional chock type of support in a one-web back mode when mining towards a roof break generated ahead of the face, while the Chinese case study compares measured subsidence over a longwall with "blocky" roof conditions with the model results. The comparisons are encouraging, suggesting that the approach used is worthy of further development.

Jan 1, 1986

By D. R. Tweeton

A modified push-pull field test and a computer model of cation exchange were developed to aid in evaluating cation exchange parameters prior to in situ mining. Reliable determination of these parameters is essential when modeling restoration of groundwater quality. The field test involves a much larger volume and much less disturbance to the ore sample than is feasible with laboratory measurements. This test can be performed in two or three weeks. It is relatively inexpensive, requiring one injection- production well and two or more wells for collecting samples of leach solution. The use of the model in interpreting test results is illustrated with field data from an in situ uranium mine. Much of the research was performed by the University of Texas at Austin, and was partially funded by the Bureau of Mines.

Jan 1, 1986

By J. Flemming, R. O. Burt

"The Tanco pegmatite is located in the Bird River greenstone belt of southeastern Manitoba approximately 160 km northeast of Winnipeg (Figure 1). This pegmatite body was discovered in 1929 and subsequently attempts were made to exploit it for tin by Jack Nutt Mines Ltd. and later in the middle 1950's by Montgary Oil Ltd., who extensively developed but did not produce from, its lithium deposits. In 1966 systematic investigation of the pegmatite as a potential source of tantalum led to the founding of Tantalum Mining Corporation of Canada Ltd. (TANGO) in 1967 and production of tantalum concentrates from the Bernie Lake mine commenced in 1969. Tanco is currently jointly owned by Hudson Bay Mining and Smelting Co., Cabot Beryl co Inc. of Boston, and the Province of Manitoba. (Williams and others 1978, Burt 1979, Burt and others 1982), continued until the end of 1982, when, due to falling demand and prices, operations were suspended.During the 1970's Tanco had investigated the potential of the lithium orebody; carrying our research into both the concentration of the ore and into the production of lithium chemicals. However lithium chemicals were in an over-supply situation, due in part to the production from Chilean brine deposits (Buckley, 1983), and Tanco' s own plans were put into abeyance. The potential alternative market, the direct use of concentrates in the glass and ceramics industry, did not at the time justify the cost of constructing a new plant."

Jan 1, 1986

By D. Spindler

Pursuant to the Federal Surface Mining Act of 1977 and the Illinois Surface Mining Act of 1980, Illinois has adopted revegetation success standard regulations that include the Agricultural Land Productivity Formula. The Formula establishes yield goals and standards to measure the success of meeting yield goals for reclaimed prime farmlands. The formula compares the quality of the pre-mining soils in the permit area and the county, to the crop production achieved on the reclaimed permit area and the county crop yield in a given crop year. The regulations also specify acceptable crops, erosion control requirements and time frames for demonstrating success.

Jan 1, 1986

By Michael F. Jeglic

Dust control methods are practiced throughout the mining industry in order to protect the health and safety of its workers, the integrity of the environment, and to guard against the loss of valuable product. The use of water is often the best and most economical method of controlling dust. Increasingly, chemical agents are being chosen over more traditional mechanical means of controlling dust. Some chemicals are used alone, and many are used to enhance the dust controlling properties of water. This paper describes the various types of chemicals available and their applicability to specific problems encountered by industry.

Jan 1, 1986

By F. D. Huntley

Raw materials used by the Flat Glass Industry are known in the Industrial Minerals geology sector as Specialty Products. These pro- ducts must meet specification limits usually not the same for all glass manufacturers. Evolving new glass compositions will require mineral concentrates of consistent purity being produced within economic limits that will assure market viability of the resulting glass product. The amount of success the Flat Glass Industry will achieve by developing and maintaining domestic production centers will be determined by many economic factors which affect the costs of doing business. Technological developments by mineral processors must continue in order to achieve more efficient production of high quality glassmaking raw materials.

Jan 1, 1986

By Fang-tu Wei

The purpose of developing this system is to monitor the operating status of the fully mechanized mining system in order to raise it's reliability. The completely mechanized coal mining system is a complex dynamic system, involving many sub-systems. It is the key of the mining process as well as a connected system composed of each working procedure. Any hitch in breaking, loading or transporting will interrupt the mining process. The analyses of the operating data has proved that the reasons causing the interruption of the extracting processes mainly come from the inner of coal face. Hence, after the installation of the MINOS system in England, the delays of belt conveyor sub-system were reduced. But the production increment was not as much as expected.

Jan 1, 1986

By Fuller P. G, Miller D. R

Hydraulic fill using surface sand deposits or cycloned tailings has been used in underground mining for at least fifty years. Current technology requires a permeable fill and high cement additions for strong fill. Shortages in quantities of acceptable fill with finely ground ore may require rockfill or aggregate to be introduced as a supplement and these usually incur additional distribution costs. Alternative approaches to the problem are now being developed whereby the pulp density of the fill is raised so that it is delivered either as a dense slurry or as a paste. These regimes of fill behaviour are defined together with the plant and pumping techniques required to prepare and deliver the materials. Test techniques to define the different regimes of behaviour are identified and the variation in material properties for fills with varying pulp densities are outlined. The results indicate that high pulp density fills are stronger and have less permeability restrictions than conventional fills and that aggregate can be carried with the pulp. Thus the disadvantage of finer materials can be turned into an economic advantage. Criteria are developed for defining the type of operation suited to this Technology.

Jan 1, 1986

By R. A. Speirer, T. C. Bettinger, L. P. Richardson

INTRODUCTION The Bureau of Mines (The Bureau) remote sensing researchers at the Denver (CO) Research Center, have been investigating computerized methods to detect and map surface linear features called "lineaments" for ground hazard assessment in mines. Many of these lineaments at the test mine site were found to correlate to subsurface geologic discontinuities such as faults, fractures, and joints that intersect coal seams at depth. These features adverse1 y affect the roof and rib integrity in underground mines, thus contributing to rock failures that may result in injuries to mine workers and loss of production. Advance knowledge of the existence of such hazardous geologic features can aid in mine planning and development. Lineaments may be observed in a variety of images of the earth's surface. Linear features that can be observed using Landsat mu1ti spectral scanner data (MSS) images range from regional (greater than 3 miles in length) to an intermediate length of from 1 to 3 miles. These images are recorded in discrete radiation bands in the green, red, and near-infrared portions of the el ectromaynetic spectrum. These data are acquired from the EROS Data Center of the U.S Geological Survey, Sioux Falls, SD, in digital format on magnetic tapes that are suitable for processing on certain minicomputers. Shorter lineaments length (less than 1 mile) can be observed in high- to low-a1titude aerial photography, radar, and infrared images with image scale ratios of 1:1,000,000 or less. These linear features can correlate to smaller dimensioned faults, and to fracture and joint sets at the local geologic scale. Other informational sources can help substantiate 1ineament analyses, such as well logs, mine naps, topographic data, and geophysical data acquired over the study site. These data must be in a digital format to process on the "DEC PDP 11/23 minicomputer system1". Data can be acquired in

Jan 1, 1986

By Ramesh Malhotra

Overseas coal trade has increased from 169 to 274 million metric tons (tonnes) between 1970 and 1983, representing a 3.8% average annual rate of growth. Metallurgical coal accounts for nearly 61% of the international coal market while steam coal's share is about 40%. By year-end 1983, the U.S. was the single largest coal exporter at 77 million tonnes, followed by Australia, 56 million tonnes; Poland, 35 million tonnes; South Africa, 28 million tonnes; USSR, 27 million tonnes; and Canada, 17 million tonnes. Coal exports can play a more significant role for one country than another country. For instance, in the U.S., coal exports accounted for only 9% of total coal demand in 1984 while in Australia, exports accounted for 53% of that country's total coal demand. Of all the major coal exporters, only U.S. exports accounted for less than 10% of total consumption in 1984. Japan is the largest importer of coal, 73.8 million tons in 1983. Although the majority of Japan's imports are metallurgical coal, steam coal imports into Japan increased seven-fold between 1978 and 1983, from 2 to 14 million tonnes. Australia is the leading exporter of both metallurgical and steam coal to Japan, accounting for 47% and 55% of Japan's coal imports, respectively. Since 1978, South Africa has developed into a major steam coal exporter to Japan, increasing its market share from 7.9% to 18.8%. The U.S., which was not even a player in Japan's steam coal market in 1978, has made inroads and accounts for 6.7% of Japan's steam coal imports. However, this translates into only one million tonnes. In the European coal market, for the most part, the U.S. is the leading supplier of metallurgical coal and South Africa is the major supplier of steam coal. The U.S. was not even a factor in the European steam coal market in 1978 and has made inroads during the last six years at the expense of Poland and South Africa. From 1978 to 1983, the U.S. has increased its market share in steam coal exports to France from 0.2 to 28%; Spain, 0 to 52%; Italy, 0 to 43.5%; Denmark, 0 to 19%; Germany, 0.5 to 16%; and the Netherlands, 0.6 to 45%, respectively. The use of coal (solid fuels) as a fuel to produce electricity has had increasing signficance for most of the countries analyzed between 1978 and 1983. The flip side to this is that oil has lost its share of this market during this time period. Of all the countries selected, only France reported a decline in coal's share of total electricity production. This is a reflection of France's ambitious nuclear program.

Jan 1, 1986

By V. Itkin

"Three methods were tested for the beneficiation of aluminum scrap, generated by heavy medium separation of non-ferrous automobile scrap residue. These were: crushing in a shredder followed by screening; grinding in a ball miff followed by screening; and eddy current separation. The best results were obtained with the grinding-screening method. IntroductionThe usual method of aluminum alloy reclamation from non-ferrous automobile scrap residue consists of a two-step heavy medium separation to remove materials lighter than and heavier than aluminum. The resulting aluminum scrap still contains over 15% impurities such as stones and glass, heavy rubber, insulated copper wire , plastics and heavy metals entrapped by macerated aluminum piece s, composite fragments, etc.(2). Upon melting, these impurities create difficulties and yield a low ingot recovery-65% to 70%, hence small foundries avoid this material.There are a number of ways to improve the quality of aluminum scrap such as:(1 ) crushing of the scrap, which powders the brittle content , a major impurity component, followed by screening out of the dust(2) eddy current separation , which removes metals from the material flow, and(3) implement better methods for density separation.The eddy current separation and two variants of the comminution-screening technique were studied by Intermetco Ltd., Hamilton , Ontario."

Jan 1, 1986

By D. S. Robertson, G. E. Nutter, T. P. Podolsky

"IntroductionBasal Proterozoic quartz-pebble conglomerates are found both west of Elliot Lake, in Duncan, Jarvis and Aweres Townships, north of Sault Ste. Marie and to the east and northeast of Sudbury, Ontario. Locally, while well packed and pyrite-rich, they carry little to no uranium. Locally, they carry gold. These features generally are ascribed to variations in the source areas of the rocks.In two other areas of Canada, similar basal Proterozoic units contain quartz-pebble conglomerate beds with uranium.Sakami LakeLocation and HistoryThe Sakarni Lake uranium deposit is found in a narrow, northeast-trending, Archean greenstone belt located 95 miles southeast of Fort George, on James Bay, and 240 miles north of Matagami, Quebec (Fig. 1).The deposit was detected by Inco in 1971, during an airborne EM survey which carried a newly developed Inco spectrometer system flown at 450 feet. Ground investigation, in 1972, resulted in the discovery and sampling of quartz-pebble conglomerate which yielded assays as high as 0.19% U3O8.Extensive field exploration was conducted between 1972 and 1975. Sixty-five diamond drill holes, to a total of 13,969 metres, served to define the extent and economic potential of the conglomerates which extend over a total strike length of about eight kilometres."

Jan 1, 1986

By R. L. Grayson

As the total cost of labor has significantly increased over the past ten years, older underground mines have found it more difficult to compete- in a limited demand coal market. Many of the older mines were developed extensively into a reserve requiring a large number of workers to maintain and rehabilitate extensive track haulages and/or belt conveyor systems. Often, a large number of fans were required to maintain minimal airflows in areas where poor conditions and huge leakages prevail. This paper focuses upon problems which beset one such coal mine and projects undertaken to restore it to potential profitability.

Jan 1, 1986

Bowdil Co. Bucyrus-Erie Co. Coal Age Coal Mining Cobre Tire Dresser Construction FMC Corp. T. J. Gundlach Machine Co. Ingersoll-Rand Joy Mfg. Co. K&P Sales Engineers, Inc. Kennametal Lively Mfg. Co. Long Airdox Co. MSA McLanahan Corp. National Mine Service Co. Page Engineering Co. Plateau Supply, Inc. Pyramid Parts Scandura, Inc. TIC Utah International Utah Power & Light Co. Western Energy Co.

Jan 1, 1986

The rare earths market is relatively small and slow growing. Three applications using mainly cerics rare earths : catalysts, glass-ceramics and metallurgy are volume market. Inside this slow moving frame, fast growing niches can be found lamp phosphors, permanent magnets, fine cera- mics... There is no specific ore for one given element, and the natural occurence of any ele- ment is almost constant in both monazite and basnaesite. This creates the "balance problem" that consists in the best compromise between shortage and over production. The general trend of prices is downward in constant money. Despite this difficult environment (price decrease, technology changes, etc...) lots of company have always been attrac- ted by the rare earth business.

Jan 1, 1986

By Athorn Mary-Lee, Randall A. Snowdon

During the development of the Selby Coalfield, UK, a Robbins full-face tunnel boring machine (TBM) and a Thyssen Titan roadheader were used to drive a pair of parallel spine roadways. This paper presents a summary of the comparative operational and cutting performance of both the Titan road- header and the Robbins TBM. Statistical techniques were employed to identify relations between machine performance and geotechnical parameters.

Jan 1, 1986

By S. K. Kawatra, R. A. Seitz

Nonpolar hydrocarbon oils are commonly used in the flotation of minerals to fulfill a number of roles. These roles include reducing overall reagent costs by replacing part of the collector addition, improving coarse particle recovery without reducing selectivity, as well as several others. This paper will cover the types of oils which are available, their physical and chemical characteristics, and the effect of these characteristics on the function of hydrocarbon oils in flotation. In addition, techniques for improving the behavior of oils will be discussed.

Jan 1, 1986

By R J. Hill

Blasters are well aware of the problems and expense faced when trying to load in wet bore holes; problems of poor coupling and poor density, as well as the expense of higher priced cartridge product. In answer to these problems, I developed a system for dewatering using nozzles with lay -flat plastic liners which I have used successfully over the last few years. I found the system not only gave me better shots than I could have expected in the circumstances, but also dramatically decreased costs. The system has been adopted by two large roading contractors and a quarry operation in Eastern Canada.

Jan 1, 1986