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By Charles T. Holland

INTRODUCTION Insofar as I am aware, the term rock mechanics was not in the English dictionary in 1930 when I started my graduate program at West Virginia University. Hence, I never thought that I was undertaking studies in rock mechanics when I undertook to write a thesis on the physical properties of West Virginia coal. In this case, the subject was primarily concerned with the compressive strength of coal, the elasticity of the coal, the physical weathering properties of the coal and its friability. These days investigations of rocks pertaining to such properties are included in the term "rock mechanics". Other than this aspect, the principle interest in this part of my program was that I became interested in the strength of coal from the standpoint of structural purposes, and also became cognizant of its elastic properties as well as its energy storing properties. This research also tied in with a remark that Professor Lawall made in a Mining Methods class in 1928 when he remarked that a peculiar thing was happening in the southern part of West Virginia, namely, in the Pocahontas coal field. His remarks were to the effect that pillars were blowing up in the mines and when asked why he replied the cause was not known. The failure of three-inch coal specimens, especially those in stronger coal, in non-hydraulic actuated testing machines was reminiscent of his description of those pillar bursts or bumps.

Jan 1, 1971

By L. A. Roe

The year 1867 marks the first year of commercial production of phosphate rock in the United States. South Carolina produced almost all of the domestic output of mineral phosphate until phosphate mining began in Florida in 1888. During the period 1868 to 1949 the total marketed production of domestic phosphate rock was about 186 million long tons of which 71.5 percent was produced in Florida, 18 percent in Tennessee and 7 percent in South Carolina (1). From 1949 through 1960, Florida phosphate rock production has ranged Prom 71 to 77 percent of the total domestic production. Since three-fourths of the domestic phosphate production is from the Florida field, and since most of the phosphate from the Tennessee and Western fields is not processed, but used directly as electric furnace burden, this paper will concern itself almost entirely with water requirements for mining and processing ore from Florida. Figure 1 summarizes phosphate rock production for Florida vs. total United States production over the period 1947-1960.

Jan 1, 1962

By QINGXIANG CAI, Lin Li, PENG LIU, IZHAR MITHAL JISKANI, XIANG LU, Wei Zhou, YONGLI ZHOU

The concept of green mining is to improve the mining industry in a holistic way so that it is safe, efficient, and environmentally sustainable. The purpose of this study was to develop an evaluation index system of green surface mining based on the theory of green grades. The evaluation model is comprised of three attributes (safety, efficiency, and environment), nine criteria, and 35 indicators. The fuzzy comprehensive evaluation method was used to determine the weights of indicators by taking into consideration degree centrality, closeness centrality, and betweenness centrality. Findings indicate that the environment is the most critical aspect of green surface mining, followed by efficiency and safety. The top five ranked green mining success indicators were the application of new technology, starting-off-rate of equipment, science and technology input to total investment, the number of accidents (decreased), and the production (increased). It was observed that more improvements are needed to overcome water, air, waste, and sound pollution. Attention should also be paid to land reclamation and post-mining land uses, which are key factors in green mining. The proposed model can be applied to evaluate and improve the level of green surface mining in other regions. This study provides a tool for decision-makers that can offer technical assistance to green mining.

May 26, 2020

By R. Bhaskar

The control of respirable dust in mines has been given paramount importance due to the health and safety implications associated with fine dust. The understanding of the temporal and spatial behavior of dust has been recognized as essential for increasing the efficiencies of the existing control techniques and for developing new control strategies. Mining-related studies in this area are, in general, limited. They are also mostly experimental. Some mathematical and computer analyses have been attempted. In this paper, first a review of the mathematical studies performed in the last three decades in this area is presented. Second, a mathematical model for analyzing dust flow in mines is proposed. The model takes into account a number of factors affecting dust transport. It incorporates varying dust generation source strengths and dispersion, deposition, and coagulation of dust in mine airways. Finally, application areas for the model are discussed. A computer program based on the mathematical model has been developed. The program will output the dust concentration in the mine atmosphere as a function of time and distance from the source. The amount of dust deposited on the sides, roof, and floor of the airway is also determined.

Jan 1, 1985

By M. P. Miano

Matching the productivity gains of continuous mining machines with the ever increasing performance levels achieved by longwall units has required creative thinking to assure that development is completed in time for uninterrupted longwall production. By using management information systems to coordinate support operations, the most productive planning decisions can be made. This paper focuses on the role of computer technology tools in achieving improved productivity from both longwall and continuous miner sections. The primary emphasis is on the planning process and the methodology developed to guarantee the best allocation of management and manpower resources.

Jan 1, 1993

By W. W. Bristol

The Jerritt Canyon Joint Venture project is located approximately 50 miles (80 km) north of Elko. Nevada, U.S.A. and produces between 250 and 300 thousand ounces of gold annually. The Joint Venture is 70% owned by Independence Mining Company and 30% owned by Meridian Gold Company. Independence Mining Company is the operator. The Jerrin Canyon Joint Venture started operations in 1980 mining a series of open pit mines. Since the early 1990's, the discovery of deeper ores has required the joint venture to develop and mine a significant portion of its annual production utilizing underground mining methods. Underground production started with the West Generator Mine in 1993 followed by the Murray Mine in late 1994. Presently, two additional underground projects are being developed. Underground mining at Jerritt Canyon is budgeted to produce 128 thousand ounces in 1997. This paper documents the major transition/redevelopment of the Jerritt Canyon mining methods.

Jan 1, 1997

By J. Wiese

Recently the operating philosophy at concentrators processing platinum bearing ores has started to move from a recovery dominated system to one in which the production of high grade concentrates at the expense of some recovery would provide greater benefits in the further upgrading of the platinum group minerals (PGM). The low grades usually obtained are associated with the presence of naturally floatable talcaceous gangue minerals in all PGM ores. Polysaccharide depressants such as guar gum and carboxymethyl cellulose (CMC) are used to improve the grades of the concentrates. Recent testwork has shown that the use of high depressant concentrations can prevent any naturally floatable gangue from reporting to the concentrate. The only gangue present in the concentrates would be due to its entrainment in the froth. Under these conditions much higher grades can be achieved. The sulphide minerals themselves, however, become susceptible to depression at high depressant concentrations. This work examines how the recovery of sulphide minerals in two Merensky ores was affected by the type and concentration of the collector in the presence of high depressant concentration (500 g/t) and that the response of the sulphide minerals was also dependent on the type of depressant used (guar or CMC).

Jan 1, 2009

By Steve Kral

Reducing the cost per ton and increasing productivity are key factors in a mine’s profitability. Mining companies can do little about commodity prices. So to keep a mine operating at a profit, management must reduce costs and improve worker and equipment productivity in every facet of a mining operation. From mining to crushing to processing, mine management is constantly seeking new methods and technologies to improve the way it mines minerals. And it is willing to borrow techniques used by other operators.

Jan 1, 2002

By G. Brackebusch, S. J. Jung

Backfilling techniques are widely used in large-scale underground mines. Massive pillars, which have been left in place for stability, limit mining activity. Backfilling allows safe recovery of the ore remaining in pillars and assures long term stability. In deep mines expected high stress can be relieved with the backfill. Initially, waste rock was used to fill the openings with mixed results. The need to improve safety and reduce costs has prompted the industry to investigate alternatives. Hydraulic filling with Portland cement added has shown considerable promise, but little has been done to define the parameters of design effective system. The purpose of this study is to determine the relationship between backfill and mining components that can be used to effectively design a best-case hydraulic backfill.

Jan 1, 2000

By Orville D. Mussey

During, 1956 the water used in mining iron ore in the United States amounted to about 2 billion gallons and the water used in producing iron concentrates-amounted to about 166 billion gallons. By 1980 an increase of about 65 percent is anticipated in the amount of water used for mining and beneficiating iron ore. Except for boiler-feed makeup water the quality requirements for water, for mining and beneficiating iron ores are not stringent. Adequate supplies. of water for development should be available at reasonable cost with the possible exception of some in arid regions.

Jan 1, 1961

By R. Patterson

Tracer gases have been utilized successfully in a variety of industries, each with specific releasing and sampling methods. The various attributes of tracer gases are dependent on the industry the tracers are utilized in. Tracers must be chemically and thermally stable, safe, odorless, detectable at low concentrations, have a low background concentration, and should not be naturally occurring in the environment if they are utilized in underground mining applications (Thimons et al., 1974). In addition, the tracer gas should be inexpensive, non-corrosive, non-toxic, easily transportable, readily attainable, and non-radioactive (Kennedy et al., 1987). Sulfur hexafluoride (SF6) met many of these above requirements and therefore was introduced as an ideal tracer gas to use in mining industry in the early 1970?s (Thimons et al., 1974). Due to the nature of underground mining including complicated geometry, irregular flows, turbulent flows, obstructed airways, and leakages it is difficult to use conventional anemometer and smoke tube techniques to accurately measure the effectiveness of ventilation controls (Thimons et al., 1974; Klinowski and Kennedy, 1991). There have been several applications of SF6 as a tracer gas in underground metal/non-metal and coal mines. Thimons et al. conducted early testing of SF6 in an underground limestone mine and determined that it is an effective technique for evaluating auxiliary fans, estimating volumetric flow rates in large areas, and measuring low flow velocities. A rapid face ventilation measurement method (FVM) utilizing SF6 was developed by the Bureau of Mines to make face measurements in underground coal mines (Timko and Thimons, 1982). When measuring the effectiveness of jet fans in dead headings SF6 was proven more effective than smoke tubes (Timko and Thimons, 1982). Experiments related to determining methane liberation in the gob were also conducted by injecting SF6 into a borehole (Timko and Thimons, 1982). Also, in an emergency situation where the gob had to be sealed due to a fire, SF6 was released to determine the effectiveness of the seals (Timko and Thimons, 1982).

Jan 1, 2011

By Gino Vogt

In mechanized tunnelling operations, performance, consumption and safety are main factors for jobsites. One of the most important components effecting these factors, especially in slurry TBM operations, are Slurry Treatment Plants (STPs). Inadequately dimensioned and designed STPs create bottlenecks for tunnelling operation and jeopardize time schedules and performance. Inefficiently planned STPs could drastically increase consumption figures such as electrical power, bentonite, water polymers, etc. Inaccurately selected and treated suspension properties can cause a high-risk potential for the whole project. This paper debates the relevant key parameters for STPs from start to finish of a project and its results in influencing factors from the manufacturer’s point of view.

Dec 1, 2022

By L. Zhou, D. Bahrami

Mine ventilation is one of the most important aspects of mining operations in underground mines. It is critical to maintain and deliver required fresh air to the active areas to reduce the risk of overexposure to hazardous contaminants or explosive atmospheres. An unexpected or unknown event such as roof collapse, unexpected mine door closure/opening, a fire/explosion, or fan malfunction could adversely alter the airflow distribution within the mine ventilation network that could lead to a hazardous underground environment. Knowing the occurrence and location of such an incident is of critical importance. In this study, the authors developed a novel methodology to assist mine operators in quickly identifying the location of any abnormal airflow change within the network using the airflow changes at monitored airways. The concept is based on a direct derivative method developed by the authors. This paper provides the details of the developed method as well as numerical verification examples. The application of this method can benefit mine operators and safety personnel in making better decisions during a mine emergency response operation to mitigate hazardous conditions arising from an unexpected airflow disturbance

Mar 2, 2022

By Martin J. Hughes

The Eagle Mountain Mine of the Kaiser Steel Corporation is located in the California portion of the Colorado Desert at a distance of about 60 miles east of Indio, California. At the present time, this mine is producing at the rate of 5,000,000 tons of concentrate per year. A total of 1,000,000 tons of ore per year is presently being sold on the Japanese market while the remainder is consumed by the Kaiser Steel Company blast furnaces at Fontana, California. A new Pellet Plant and Concentrator is presently under, construction with completion scheduled for May or June 1965. This plant will have a rated capacity of 2,200,000 tons of pellets per year and essentially all of this production will be sold to Japanese steel companies.

Jan 1, 1965

By J. C. Draper

This subject was introduced last April in a paper presented in Birmingham, Alabama, by James E. Elkin, General Superintendent of Duquesne's Coal Department. This paper will cover some of the same data and in addition it will update and further describe our experience. Our Portal No. 3 was started in June 1965 with battery tractor-trailer face haulage. This mine is operating in the Sewickley seam in Dunkard Township, Greene County, in Southwestern Pennsylvania as shown on Fig. 1. The Warwick group of mines fronts on the Monongahela River and extends westward for some ten miles as shown on Fig. 2.

Jan 1, 1968

By N. T. Rempe

Proper use of natural resources is multiple use. Underground space resulting from mineral extraction offers opportunities for deep geologic waste disposal (DGWD) which can solve many environmental problems. U.S. government projects plan to use specially mined excavations to dispose of radiotoxic and mixed waste. DGWD takes careful planning, technology transfer, and true partnership between waste generators and mine/repository operators. Using the experience, accumulated by domestic projects in preparation, and by foreign repositories in operation, U.S. mines can claim their rightful share of the growing market for DGWD.

Jan 1, 1996

By H. E. Wyslouzil

The highly competitive nature of the international iron ore market has forced producers to improve the quality of their pellets. The demand for low acid pellets suitable for direct reduction has resulted in an increase in the number of plants utilizing reverse froth flotation for silica reduction. Column flotation is being favoured for this service due to the low capital and operating cost of the equipment, as well as improved metallurgical performance when compared to conventional flotation cells. This paper describes the benefits of column flotation and discusses some important aspects of circuit design.

Jan 1, 1993

By R. J. Lutton

The U. S. Army Corps of Engineers is seeking empirical slope data from mining companies and other organizations to help establish guides for engineering Judgment in crater excavation for canals and other civil works. Slopes from about 100 open pits and other excavations range in heights to greater than 1000 ft. Factors known or expected to affect stability (and optimum slope inclination) are: geological structural orientation, geological structural ordering, method and technique of blasting, design life of slope, groundwater conditions, depth of excavation, climate, and height. These and other more subtle factors appear to combine and produce an overall effect brought out best on a family of empirical curves relating slope height and inclination.

Jan 1, 1968

By John W. Rold

These encompass all adverse effects of oil shale mining, processing, and ancillary developments on the environment. Specific problems concern: land, vegetation, wildlife, water, air, population growth, aesthetics and public emotion; and fall into four categories of: land, water, air and emotion. Land includes excavations, spent shale disposal, loss of vegetation and impact on wildlife and domestic grazing, plant sites, buildings and roads, necessary urbanization and the total aesthetic or visual Impact. Water considerations are: requirements for Industrial and domestic supplies, adverse effect of underground water on mining, avoidance of pollution or adverse effect on surface or near-surface water, and the utilization or safe disposal of liquids. Air problems include dust, smoke and stack gas, Public emotional problems include reaction to the above problems, and misconceptions of oil shale country and an oil shale Industry. Government and industry are aware of the problems, and are seeking solutions. Last year, the three affected states studied oil shale environmental problems and solution costs. Colorado estimated environmental costs would add approximately 7% to construction and 7% to operation. The report suggested research in: (1) Water availability and impact; (2) Disturbed lands revegetation and rehabilitation, including spent shale; (3) Environmental inventory and impact; and (4) Regional development and land use planning. Governor Love appointed a 47-person committee representing Industry, government and environmentalists to attack the problems. Research pro-posals were prepared to focus on each problem. $715,000 state, federal and industry money is being committed. Results should provide data for industrial solutions and equitable agency administration.

Jan 1, 1972

By E. D. Stephenson

As part of the British Steel Corporation?s development plan during the 1970?s, it was decided to concentrate its bulk steelmaking processes based on the BOS at 4 major Works with access to deepwater ore terminals, for the supply of high-grade imported ores. These 4 sites were at: - 1. Rarenscraig Works in Scotland where the ore terminal would be hilt at Hunterston on the west coast some 50 miles away. Bavenscraig was already an integrated Works but suffered from having to discharge ore 27 Glasgow tenxinus on the River Clyde, which could only accommodate vessels up to 25,000 tonnes. In the future, ore was to be unloaded at Runterston and shipped by a rail-link into Ravenscraig, The new ore terminal would have the potential to unload vessels up to 300,000 tonnes. - 2. Port Talbot Works in south Vales where the existing harbour was developed to discharge large ore carriers. This again was an existing Integrated Works and the benefits of the new harbour also applied to Llanwern Works which was another integrated Works some 50 dies to the east, which would now receive ore from Port Talbot.

Jan 1, 1980