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By R. Allan Wallis

In the past mining engineers have tended to rely heavily on the advice of fan manufacturers in relation to fan equipment issues. A more adequate approach was advocated in a paper [ Wallis, 1965 ] submitted to the Eighth Commonwealth Mining and Metallurgical Congress held at Surfers Paradise, Australia during 1965. At that time Mount Isa Mine were in the process of installing 3 large 6096mm (20ft) diameter vertical axial flow surface fans of an advanced type [ Mathews et al, 1967 ]. The preliminary feasibility studies prior to preparing the detailed job specification for this project were extremely thorough with the result that it was possible to include detailed information and instructions in the document, ensuring the procurement of equipment that was satisfactory in all respects. Full advantage was taken of expert services provided by external organizations during the large coordinated multi-disciplinary exercise. My continuing activity and development in relation to the technology of axial flow fans is now at a stage where all known design and performance data are accessible through CAD programs [ Wallis and Kipp, 1987 ]. The extensive calculations that were necessary in 1983 can now be carried out in a mere fraction of the time, and with complete confidence. Model testing in order to validate the fan and duct design proposals is, in my view, no longer essential. The first of the computer programs enables a mine ventilation engineer to study a large number of alternative axial fan arrangements for comparison with the centrifugal alternative. By entering the volume flow rate, fan pressure and air density, he can then with ease, and rapidly, investigate the effect of various blading arrangements, downstream evasee area ratios, and hub ratios, on fan diameter and speed, with their related attainable fan efficiencies. This procedure had its origin back in the 60s when I was advising mining companies on new fan equipment. At that time such an investigation was quite lengthy and lacked the precision and completeness that is now available within the present programs. To obtain the major benefit from these outputs, it is most important not to be disconcerted by the three very important nondimensional parameters, namely, the tip flow coefficient (LAMt), the fan pressure coefficient (Kt or Kit), and the swirl coefficient (Es and/or Ep) as these are important when assessing the various design proposals. When seeking an understanding of the role and importance of each of these variables, ample help is provided in the user manual; the design recommendations are summarized in the help screens which are readily accessible within the design programs.

Jan 1, 1989

By Richard B. Berg

California was a major talc-producing State until the late 1980s when production from the deposits in the Death Valley area ceased because of a number of factors which included pressure to discontinue mining in and around Death Valley National Monument, and health concerns affecting markets for tremolitic talc. The states of Montana and Texas now account for slightly more than half of U.S. talc production. Deposits in an area encompassing southern Death Valley and extending east into the Kingston Range were formed by contact metamorphism of carbonate beds in the Precambrian Crystal Spring Formation next to Precambrian diabase sills. These deposits contain ore ranging from high-purity, fine-grained talc to platy, tremolitic talc with high brightness. Deposits of tremolitic talc and talc schist in the Silver Lake District in San Bernardino County resulted from metamorphism of Precambrian carbonate beds intruded by granitic plutons. Northeast in Esmeralda County, Nevada hydrothermal alteration related to Late Jurassic plutons caused talc replacement of Precambrian to Early Cambrian dolomite. A hydrothermal origin is also indicated for talc deposits in the lnyo Range just north of the Death Valley District where bodies of unusually pure talc occur in Paleozoic lime- stone near Jurassic granitic plutons. Talc is now mined from a deposit in the foothills of the Sierra Nevada Range southeast of Sacramento where quartz-mica schist of the Permian Calaveras Formation has been hydrothermally altered to talc. Replacement of magnesite of the Precambrian Allamoore Formation produced talc deposits mined in the Allamoore District of west Texas. This dark-gray talc of low iron content with carbon- aceous material and dolomite is ideally suited for use in ceramics where it makes a white product when fired. Small bodies of platy light-pink to white talc suitable for use as an extender in paint are also mined in this district. In the Llano District of central Texas talc has replaced impure carbonate rocks and serpentinite. All Montana talc production is from deposits in the southwestern part of the State that formed by Precambrian hydrothermal alteration of dolomitic marble. This alteration produced material with high purity that ranges from very fine-grained, massive talc to coarser grained, foliated talc. Markets include pitch control in paper, paint, cosmetics, ceramics, rubber and plastics. In southwestern and northeastern Oregon, talc has replaced serpentinite in the vicinity of Mesozoic plutons. Soapstone for carving is mined from a southwestern Oregon deposit. Deposits of similar origin occur in central and northwestern Washington.

Jan 1, 1995

By Felicia F. Peng

In operation of column flotation of fine coal, the smaller bubbles are required to effectively recovery of fine hydrophobic particles. However, smaller size bubbles alone does not ensure an efficient flotation for fine particles. The sufficient available bubble surface area per unit column are essential for effective column flotation. The experiments are conducted in a lab-scale column using two different bubble size distributions and three different particle size distributions for flotation of Pittsburgh No.8 seam coal. The interaction between particle size, aeration rate, feed rate and wash water addition are examined in this investigation to establish the optimal operation conditions for flotation of fine coal. Despite of wide range of operation conditions used in this study, it is found that the experimental data fall in a single characteristic recovery-ash curve for a given bubble size distribution and particle size distribution. The major parameters affect the flotation performance points along -the characteristic recovery-ash curves are aeration rate/frother dosage, feed rate and wash water rate-.

Jan 1, 1994

By Gretchen K. Hoffman, George S. Austin

Soil amendments or soil conditioners generally carry the con- notation of being useful for problem soils or soils needing special treatments to produce maximum yields. Many different materials have been utilized, both inorganic and organic. Only the most commonly used and those that appear to have potential to become commonly used will be discussed. Soil productivity depends on many factors. Soil amendments mainly modify physical characteristics and microbial action, and/or change the pH of a soil, rather than directly supplying plant nutrients. They give soil the needed physical properties to allow plant growth, fight erosion, or save water. Some soil amendments provide nutrients in addition to altering the physical, biological, or chemical characteristics of soil. The term "soil amendment," as it is used by Soil Science Society of America, allows soil amendments to be materials other than those used primarily as fertilizers (Anon.,1987). Soil amendments as fertilizers of any type will not be considered here because this aspect is more relevant to the previous chapter entitled "Agricultural Materials: Fertilizers" in this volume. Several inorganic soil amendments have been used since the early 20th century to alter the character of soil: limestone, lime, and similar calcium-rich carbonates and oxides for acid soils, and calcium sulfate (gypsum) and native or uncombined sulfur for alkaline soils. The use of these amendments (limestone, lime, gypsum, and sulfur) or their equivalents has been studied and documented in many basic soils tests (McCaslin and Boyle, 1980). Perlite and vermiculite are considered in separate chapters and only a brief statement of their use as soil conditioners will be made in this chapter. Peat is the principal natural organic soil amendment, but manure, both as a fertilizer and soil conditioner, is used in every part of the world. In less-developed countries, manure is the primary soil fertilizerlconditioner. An organic-rich material designated as "humate" has been marketed as a soil amendment for many years and will be addressed in this paper. Other materials are discussed by the Soil Science Society of America in its Special Publication 7, "Soil Conditioners" (Stewart, 1975). They include bitumen emulsion, polyacrylamide, polyvinyl acetate, polyvinyl alcohol, bentonite, nonionic surfactants, and natural mulches. Zeolites can be added to the list of miscellaneous soil amendments (McCaslin and Boyle, 1980), as can calcium chloride (Pressler and Pelham, 1985), sulfuric acid, ferric and ferrous sulfate, aluminum sulfate, ammonium polysulfide, calcium polysulfide, and ammonium bisulfite (Stromberg and Tisdale, 1979). Sludge will not be considered as a soil amendment because it has properties more consistent with fertilizers. All these "other materials" account for a very small amount of the volume and value of soil amendments used and will be only briefly discussed.

Jan 1, 1994

By J. Litsenberger, T. E. Marshall, P. R. Coyle, L. J. Prosser, A. T. Iannacchione

For the first time in an underground stone mine, the relationship between roof movement and microseismic emissions was examined in conjunction with two distinct roof fall areas. As roof monitoring increases in acceptance and monitoring technology advances, the goal of providing reliable roof fall detection systems to enhance the safety of underground mine workers moves closer to reality. Instrumental to reaching that goal is the ability to interpret accurately and completely roof movement and microseismic emissions, which can serve as precursors to roof falls. This paper examines the capabilities of convergence and microseismic monitoring systems to better understand roof rock failure mechanics and to anticipate roof falls. An understanding of how these techniques are used and how they interact with each other is critical in developing the most effective ground control strategy for our nation’s mines.

Jan 1, 2004

By J. Iannicelli

High intensity, high gradient magnetic separation can economically remove weakly paramagnetic contaminants down to 0 1 micron from industrial minerals This process is employed by all waterwashed kaolin producers in Georgia where seventeen huge magnetic separators are used to upgrade this product As a result, reserves of kaolin in Georgia have been doubled Design improvements have steadily increased the efficiency of separators and reduced power consumption below 300 KW for a nominal 65 TPH unit Beneficiation of ultrafine minerals is discussed based on pilot plant results on bauxite, ball clay, calcium carbonate, glass sand, talc, and numerous other minerals Operating parameters of the process are reviewed and some alternative equipment configurations discussed

Jan 1, 1983

By S. Norman Kesten

The Resource Conservation and Recovery Act, commonly known as RCRA, which amends the previous Solid Waste Disposal Act, was signed into law on October 21, 1976. Members of the mining industry began their contacts with EPA in this area two to three years before the Act finally was passed, and that seemed and probably was all to the good. We reviewed and commented upon their studies and in general tried to acquaint them with the peculiarities and the uniqueness of the wastes generated by our industry, of which they were abyssmally ignorant. I suppose we thought that through the bureaucracy we might have some influence upon the provisions of the solid waste legislation that was being bandied about on the hill. Certainly the industry, in general, did very little direct lobbying, as I recall, and there were several reasons for that. For one thing we conceived that the legislation was aimed at the chemical industy and believed that if their people looked after their interests, ours would be safeguarded automatically. Also, the Federal Land Policy and Management Act (FLPMA) was heating up at the same time and, in fact, was signed into law on the same day. In addition, a great deal of lobbying activity was required by amendments of the Clean Air Act and Federal Water Pollution Control Act that were being put together in Congress. These were conceived to be of far greater importance to our industry than a bill to control mostly chemical wastes and, in fact, new bills in both areas became law the following year. Finally, the solid waste bill, RCRA, was patched together by committee staffs over one weekend and was reported out by a conference committee rather hurriedly. Some little goodies about mining were almost after-thoughts in this process.

Jan 1, 1981

By William C. Peters

"A large proportion of the earth's surface is blanketed by young sedimentary formations and by recent lava flows. How many Guanajuatos lie concealed beneath the rhyolitic capping of the Sierra Madre of Mexico? How many Kirkland Lakes are under the drift cover of the Canadian Shield? How many Wilunas are still hidden by the alluvium of the desert of Western Australia? How many ore deposits lurk underneath the basalt-covered plateaus of the Columbia River region? If erosion at Goldfield, Nevada, had stopped 100 feet higher, probably no ore would have been exposed. How many Goldfields are still awaiting discovery?" --Hugh Exton McKinstry, 1948

Jan 1, 1969

By I. E. Odom

The physiochemical properties and industrial uses of the clay mineral montmorillonite are reviewed. Montmorillonite is the most abundant species of the smectite clay mineral group and is the predominant mineral composing bentonite deposits. The crystal structure, chemical composition, exchangeable ion type, and small crystal size are responsible for several unique properties, including a large chemically active surface area, a high cation exchange capacity, and interlamellar surfaces having unusual hydration characteristics. The type of exchangeable ion, sodium (Na), calcium (Ca), and/or magnesium (Mg), has a major influence on industrial and chemical uses of montmorillonite because of their hydration characteristics. Natural occurrences of Na mont¬morillonite in commercial quantities are geographically limited, but Ca-Mg montmorillonite deposits are known worldwide. Foundry, well drilling, pelletizing, and civil engineering constitute the major uses of montmorillonite, but the total array of uses exceeds that of any other mineral.

Jan 1, 1988

By Thomas V. Durkin

About 1.41 kt (45.2 million oz) of gold have been ! produced in South Dakota since 1875. South Dakota's mining laws attempt to strike a balance between economic development and environmental protection. Mining is promoted as an industry while prevention of pollution is required along with reclamation of affected lands to a beneficial use. The South Dakota Department of Environment and Natural Resources' (DENR) system of "one-stop shop- ping" for environmental permits streamlines the permit process. It fosters quick resolutions to compliance problems and helps keep enforcement actions out of the courts. Paha Sapa means "Hills that are Black" in Dakota Sioux. Appearing dark from a distance due to a thick forest of Ponderosa pine, the Black Hills were gold to many people. The exact date that gold was discovered in the Black Hills remains debatable. An inscribed stone tablet found in 1887 near Spearfish recorded these words:

Jan 1, 1998

By A. E. Hall, D. M. Mchaina

This paper outlines a proposed research project to investigate secondary sulphide ignitions. Sulphide dust explosions have resulted in loss of production and considerable capital and equipment replacement cost in Canadian mines. The practical application of laboratory test results to actual mine situations presents a complex problem and is a field requiring immediate investigation. The factors contributing to the outbreak of sulphide ignitions are not clearly understood. This indicates a need for future research to study the influence of blasting parameters, exhaust temperatures, and dust characteristics on secondary ignitions at source. The aim is to establish realistic quantities for each of the parameters and develop a model that will incorporate field and laboratory quantities. It may be possible to predict outcomes of sulphide ignitions when the parameters are known. It is also planned to study the techno-economic feasibility of the preventive and control methods. One aspect of planned future research requires quantification of some terms by obtaining measurements of pollutant concentrations and size distribution of the airborne dust in an underground environment immediately after a main blast. A blast-proof aerosol sampling package to measure the source term will be designed. This sampling package will consist of a sampling section and a shield which will be capable of withstanding a blast explosion. The accuracy in measuring the variables and combination of variables will be the main focus in this proposed study.

Jan 1, 1987

By W. M. Kidd, P. J. Duport

INTRODUCTION The enquiry of the Royal Commission on Health and Safety of Workers in Mines of 1976, known as the Ham Commission after its chairman, Dr. J. Ham , now president of the University of Toronto, was one of the activities surrounding the upturn in the fortunes of the Canadian uranium industry and its markets in the mid-seventies. Although the regulation and licensing of Canada's ten major mine/mill facilities employing six thousand or more uranium mines is a federal concern under the Atomic Energy Control Act, this Commission, which paid particular attention to health and safety in uranium mines, was appointed by the Province of Ontario. Further provincial enquiries in British Columbia, Saskatchewan and Newfoundland have been aimed at quantifying, reducing or eliminating the environmental and health impact of uranium production. This work has created a mosaic of provincial regulation in what is essentially a field of federal jurisdiction. Various organizations of the federal government related to its regulatory function in the uranium industry are outlined in Figure 1 showing the matrices of regulatory, advisory and research activities associated with the exploitation of Canadian uranium resources. A more detailed examination [ ] of the governmental (federal and provincial) activities, commissions, etc., in the Canadian uranium industry indicates a definite parallelism of effort, if not of scale between the two levels of government in the execution of their roles in occupational and environmental health and safety and is presented here to explain the complex stage onto which the Canadian Institute for Radiation Safety has just entered. The development of the Institute and its precursors together with current and planned research activities are described. BACKGROUND Traditionally and constitutionally, natural resource exploitation and its regulation is under provincial jurisdiction; however, the uranium industry has been under federal control since the Second World War when security measures necessitated the creation of the Atomic Energy Control Board (AECB). Health and safety aspects, in terms of inspection, compliance and environmental monitoring are performed on behalf of the AECB by provincial labour inspectors (Saskatchewan and Ontario) and Ministries of Environment. Non-radiation health and safety matters are also enforced under the federal Canada Labour Code by provincial inspectors. In support of licensing and standard-setting functions, major research programs have been initiated and expanded at both the AECB and the Canada Centre for Mineral and Energy Technology (CANMET), formerly the Mines Branch of the Federal Department of Energy, Mines and Resources). CANMET established a Mining Research Laboratory at Elliot Lake, Ontario in 1965 to conduct research and development aimed at improving production capability, providing information on the security of uranium supply and investigating the hazards of mining and their implications for the health and safety of the miners. The provincial route in assessing the costs and benefits of uranium production has attempted to be far more conclusive in nature. While some on-going studies are funded, periodic inquiries by Royal Commission have become the accepted practice. Six such inquiries have been conducted in four provinces and widely differing policies have resulted from their findings and recommendations. For example, while the government of British Columbia in the Fall of 1980 declared a seven-year moratorium on(2) uranium mining and exploration in the province, the province of Ontario's crown utility "Ontario Hydro" financed the rehabilitation of a mine/mill complex at Elliot Lake. The latter instance is not surprising considering that the final report of Ontario's "Royal Commission on Electric Power Planning",(3) concluded that nuclear energy has a continuing role to play in the expansion of Ontario Hydro.

Jan 1, 1981

By K. S. Narasimhan, T. C. Rao, R. Bhima Rao

Investigations have been carried out to evolve a grinding aid useful in grinding a 40% iron-bearing magnetite containing quartz as the major gangue, based on studies conducted with pure magnetite, pure quartz and its synthetic mixture. These investigations established that an addition of 200 g of CaO per metric ton of ore was the most effective in grinding quartz preferentially over magnetite at 75% solids concentration by weight. The limited rheological studies conducted suggest that the effect could either be due to dispersion or the structural modification of quartz. More importantly, a new concept, that of Critical Solids Concentration, where two different minerals behave like one with respect to response to communication in a tumbling mill, has been introduced for the, first time. Above this concentration, one of the minerals is ground at a faster rate than the other, whereas the reverse is the case below this concentration.

Jan 1, 1992

By D. R. Dolinar, J. Pablic, D. C. Oyler, T. P. Mucho

At a mine in central PA, high horizontal stresses have caused long running roof falls resulting in hazardous conditions for the miners and the premature abandonment of panels. Because of these conditions, the mine requested assistance of the National Institute for Occupational Safety and Health (NIOSH) in utilizing the "advance and relieve" method to mitigate the affects of horizontal stress on the mine roof. "Advance and relieve" mining involves the removal of a pillar or a portion of a pillar during development, thereby creating a cave along one side of the panel. Following cave development, the horizontal stress is relieved over the workings adjacent to the cave in the active panel. The mine has used this system in three panels with a significant reduction in stress damage and no large roof falls.

Jan 1, 2001

By J. W. Shuster

Test of trolley-diesel prime power is another step in the search to exploit the unused potential of electric wheel driven haulage trucks. The output of the present engine - a 700 horsepower diesel - is not adequate to exploit fully the 1200 horsepower potential of the two electric wheel drive motors. Power was supplied to a modified 100-ton haulage truck through a double wire trolley system. The vehicle was tested with various payloads on a 7% adverse grade haul road. More significant conclusions developed are: Power - Horsepower to propel the vehicle can he more than doubled to improve truck cycle time. Productivity - Trolley power up adverse grades can improve [producivity] rates from 18 to 36%, dependent upon haul road profile.

Jan 1, 1968

By M. Karmis

Surface subsidence has been recognized as an inevitable consequence of underground coal mining for several centuries. The damage resulting from this phenomenon has been witnessed in rural as well as in urban areas and ranges from simple land settlement to severe structural damage to buildings. Subsidence prevention is not feasible, at least under the existing technological and economic constraints of underground coal mining. Using a rational method of subsidence prediction, it has been demonstrated in many coalfields that subsidence control can be successfully practiced in order to reduce and accommodate subsidence within environmentally acceptable levels. This paper presents the development and testing of a subsidence model, based on the zone area method. This technique is a refined development of the influence functions and it is capable of investigating a mining plan of any shape, thus facilitating both longwall and room-and-pillar mining systems. More specifically, this study can be divided into two major efforts: (a) The development of the zone area model. This formulation was designed to accommodate the analysis of an optimum number of zones, over the area of interest, both accurately and efficiently. (b) The testing of the computer techniques with appropriate field measurements. In order to accomplish this, published as well as unpublished information was collected and analyzed according to a regionalized scheme. This procedure minimized differences in subsidence characteristics between the various coalfields and allowed a regional validation of the predictive capabilities of the model.

Jan 1, 1982

By Michael Bayerl

The HILTI OneStep rockbolt was implemented for roadway development in German deep coal mines in 2004. The development by HILTI Company is based on a technical joint venture with RAG Deutsche Steinkohle AG. The technical development of a One-Step bolting system was required for weak strata conditions at the roadway development face. Standard resin bolting has reached the limit of performance when boreholes are squeezed and cannot be filled with capsules. In some cases the heading face is brittle and requires additional support for installation of the bolts and a person working immediately next to the borehole. The Hilti One-Step system allows automated and safe processing at the heading front and provides the key technique to avoid these problems.

Jan 1, 2009

By Allan M. Johnson

The Sherwood Mine is being monitored to determine the nature and extent of changes in the mine and its environs which result from the closing and the cessation of pumping. Of particular interest was the possibility of piping-induced subsidence occurring as the mine flooded. Previous experience in the district indicated that this possibility was very real. A monitoring system, including acoustic sensors, extensometers, surface subsidence monuments, and ground water observation wells was installed in July 1978, just prior to the mine closing. Late in 1979, three piping-induced subsidence events occurred. The monitored data, and related laboratory studies are being applied to a quantitative description of piping-induced subsidence.

Jan 1, 1980

By Claude Hébert

The Grenville structural province, a 400 km-wide belt of Precambrian metamorphic rocks which crosses the province of Québec in a northeasterly direction, is the host of several wollastonite occurrences. Most of these are found in marble and calc-silicate rocks enclosed within or located near intrusive bodies. Reconnaissance and detailed mapping of such zones have helped to identify areas of interest for wollastonite exploration. The most important zone is located in the huge Lake Saint-Jean anorthosite massif in the central part of the Grenville. A recent geological mapping project has revealed the presence of wollastonite in metasedimentary faulted remnant of the roof. The main occurrence consists of diopside and wollastonite in a zone at least 3 km long and 150 m wide. Preliminary sampling suggests and average grade of 50 percent wollastonite with an aspect ratio of 151. Other wollastonite deposits occur in the western part of the Grenville, mainly north and west of Montreal, where the Morin anorthositic complex and a large syenite mass intrude the metasedimentary rocks of the Grenville Supergroup. Marble bands with up to 70 percent wollastonite occur locally at the southern margin of the complex or as an inclusion in the syenite. Significant wollastonite occurrences have recently been found in the eastern part of the Grenville. One of them is located in metamorphosed calcareous rocks which are part of the granulite facies Manicouagan metamorphic complex. A representative sample analyzed 54 percent wollastonite. Farther south, an inclusion diopside-wollastonite gneiss containing an estimated 40 percent wollastonite occurs at the margin of the Pentecôte River anorthositic complex.

Jan 1, 1995

Slurry technology developed for the marine transport of mineral commodities has been increasingly applied to on-shore slurry transport systems. Reclaim of mineral concentrates, sand tailings for mine backfill and various industrial minerals from storage tanks or ponds normally require a slurry of high density at constant flow rates to improve process performance and to reduce handling costs. An efficient system must accomplish this at minimum capital costs with maximum reliability. Continuing improvements in equipment design to improve repulping efficiency and their application are discussed.

Jan 1, 1986