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By R. L. Wooten

When discussing what Coal Mine Safety in the future will be, it is important to examine three areas which at present provide significant parameters to the industry. These three areas are: 1) Safety improvements in mining equipment; 2) Labor-management relations; and, 3) The politics of coal mine safety. EQUIPMENT Over the past several decades significant safety improvements have been made in the types of equipment now in use in most operations. Many of these improvements have evolved through mandates from either the U. S. Bureau of Nines, MESA, MSHA; and in some instances, the states. Cabs and canopies are examples of federal mandates while the use of ATRS initially was a state mandate.

Jan 1, 1985

By E. W. Davis

This paper deals with the role of the Maintenance Department in a milling operation; specifically, the Mines Development, Inc., processing plant at Edgement, South Dakota. The goal of very maintenance department is the smooth and uninterrupted operation of the plant it serves, To achieve this goal, maintenance men adapt various features and procedures into a program designed to fit the characteristics of their particular plant operation. A few of the basic elements of a sound maintenance program are: 1, A periodic preventive maintenance schedule. 2, A systematic inspection and lubrication procedure. 3. A training program for maintenance personnel. 4 A good equipment-history file system, 5. A carefully planned spare parts inventory.

Jan 1, 1962

By E. Alan Haley

Accurate and economic control of line and grade on long tunnels, large structures, excavations and waterways, has been a problem to surveyors and engineers for decades. The conventional method of surveying, incorporating a level, transit, and a number of surveying technicians, has proven, in the past, to be a very expensive and time-consuming operation. Alignment with a laser has solved most of the problem. Figure 1. With the advent of the Perkin-Elmer Model 5620 Construction Laser, use of laser light is now both dependable and economically feasible for unlimited applications in modern construction and surveying. The laser projects a continuous, narrow red beam of brilliant light, providing a constant alignment reference, and will not interfere with operations.

Jan 1, 1968

By F. A. Renninger

Limestone and dolomite are the most common rock types mined and quarried as industrial minerals in the United States. In 1993 over 720 million tons of limestone and dolomite valued at over 3.1 billion dollars were extracted and consumed throughout the nation. While the greatest volume of this vast production is used as aggregate for construction purposes, few people realize how critical limestone and dolomite are to our food chain and our national goals of clean air and water. Limestone, including dolomite, can truly be called nature's gift to the environment. Without a reliable, economical source of limestone the quality of our environment would be severely comprised and the standard of living of our citizens dramatically reduced.

Jan 1, 1995

By Robert E. Goodwin

There are four main requirements which must be considered when selecting a wire rope for the best serviceability. A proper choice is made by correctly estimating the relative importance of each of these requirements and selecting s rope which has those qualities best suited to withstand the combination of destructive forces expected under continued service. A wire rope should possess: 1. Strength sufficient to support the maximum load expected and with s proper safety factor. 2. Ability to withstand bending and to resist bending fatigue without failure of the wires. 3. Ability to withstand surface abuse such so abrasive wear, pounding, and wire scrubbing. 4. Ability to withstand abuse such as crushing and distortion.

Jan 1, 1968

By Chun K. Ip, Simon T. Johnson, Robert J. Fowell

Laboratory conducted cutting tests at traverse speeds up to 1 m/s have been undertaken with high pressure water jets assisting the cutting action of drag tools. Four sandstones and one limestone have been investigated, which represents a wide range of compressive strength. Variables investigated include water jet pressure, nozzle diameter, depth of cut, traverse speed, jet position, and tool bluntness. The test programme has allowed a model to be developed which describes the action of water jet assistance for three conditions dependent on the ability of the jet to penetrate the rock: where no significant penetration occurs, where penetration is greater than 50% of the tool depth, and an optimum condition around 30% of tool depth.

Jan 1, 1986

By L. S. Leal Filho, L. A. F. Barros, S. M. Assis

Zeta potential determinations and microflotation tests (with starch, sodium oleate and flotigan EDA-B) versus pH, pCa and pMg were performed with apatite and typical silicate minerals that occur in Brazilian phosphate ores: schorlomite, diopside, quartz and micas. Unlike quartz and micas, schorlomite and diopside were depressed by cornstarch during anionic flotation with sodium oleate (pH 1 9). The selectivity of the separation apatite/quartz and apatite/micas by flotation with sodium oleate was adversely affected by the presence of calcium (pCa) and magnesium (pMg) in flotation pulp. Solubility/cation exchange capacity of micas is an important source of dissolved calcium and magnesium in the system.

Jan 1, 2002

By J. M. Kruger, P. Berendsen, A. Martinez

High-resolution ground-penetrating radar (GPR) was used to image the near-surface extent of two exposed Late Cretaceous kimberlites intruded into lower Permian limestone and dolomite host rocks in northeast Kansas. Six parallel GPR profiles identify the margin of the Randolph 1 kimberlite by the up-bending and termination of limestone reflectors. Five radially intersecting GPR profiles identify the elliptical margin of the Randolph 2 kimberlite by the termination of dolomite reflectors near or below the kimberlite's mushroom shaped cap. These results suggest GPR may augment magnetic methods for the delineation of kimberlites or other forceful intrusions in a layered host rock where thick, conductive soil or shale is not present at the surface.

Jan 1, 1998

By J. M. Kruger

High-resolution ground-penetrating radar (GPR) was used to image the near-surface extent of two exposed Late Cretaceous kimberlites intruded into lower Permian limestone and dolomite host rocks in northeast Kansas. Six parallel GPR profiles identify the margin of the Randolph 1 kimberlite by the up-bending and termination of limestone reflectors. Five radially-intersecting GPR profiles identify the elliptical margin of the Randolph 2 kimberlite by the termination of dolomite reflectors near or below the kimberlite's mushroom-shaped cap. These results suggest GPR may augment magnetic methods for the delineation of kimberlites or other forceful intrusions in a layered host rock where thick, conductive soil or shale is not present at the surface.

Jan 1, 1997

By L. Evrard, M. Van Camp, J. Y. Yen, R. G. Reddy, D. Mantha

Viscosities of two industrial lead blast furnace slags have been experimentally determined as functions of composition and temperature. A Brookfield viscometer with alumina rods and crucibles were used. Experiments were carried out between 1200 and 1573 K in an argon atmosphere with up to 5% addition of FeO, MgO, and SiO2 to the slags. Results showed that 1) the viscosities of two slags decreased with increase in temperature; 2) addition of FeO decreased the slag viscosities; and 3) addition of MgO and SiO2 increased the slag viscosities. Use of the above slag compositions with the addition of FeO is recommended for successful lead smelter operation.

Jan 1, 2005

By D. M. Richards, A. D. MacPhail

Highland Valley Copper currently mines two low-grade ore bodies, Lornex and Valley. The partnership was formed in 1986. As a cost reduction measure, it was decided to use an in-pit crushing and conveying system to deliver the ore from the Valley Pit to the Lornex mill 3 km (1.8 miles) away and 175 m (575 ft) above the pit rim. The system uses two gyratory crushers that feed a series of conveyors to transport up to 130 kt/d (143,000 stpd) to the main stockpiles. This paper describes the performance of the in-pit crushing system as it is currently configured, as well as its evolution to date and future planned moves.

Jan 1, 1995

By J. Vaino Huhta

An exploration program which covered an area of about 17 000 km2(6564 sq miles), was carried out between 1966 and 1969 by the United Nations project named "Mineral Survey of the Azuero Area." The target became Cerro Petaquilla, Province of Colon, Panama. See Fig. 1. Regional exploration led to discoveries of many geochemical anomalies and minor mineralization, but it was only toward the end of the project that a promising target was indicated by a large zone of comer and molybdenum anomalies in stream sediments in a remote 1, area between the Cordillera and the Caribbean coast. Follow-up surveys established the presence of porphyry-type copper mineralization in the area now known as Cerro Petaquilla.

Jan 1, 1991

By C. Anastasiadis

The wettability of sandstone was investigated using the technique of dielectric spectroscopy in the frequency interval 1kHz-1MHz. The natural wetness of the material was modified to get two different sets of samples, one with sea-water wetness and the other with crude oil wetness. Measurements showed that the electric responses of water-wet and crude oil-wet samples were markedly different beside the fact that the dielectric response of both groups of samples obeys a general fractional power law. The dispersivity, of the complex permittivity component that expresses the material loss with respect to the electric field was found to be the most suitable parameter to check the wettability of the samples.

Jan 1, 2005

By Edward C. Spalding

The mineral estate of Arizona's State Trust lands, which are administered by the State Land Department for the benefit of the common schools and 14 other beneficiaries, totals more than 10.5 million acres, or almost 15 percent of the State's entire area. Trust lands exist in all 15 of the State's counties, with the most and least acreage found in Yavapai and Gila Counties, respectively. Revenues derived from the Trust mineral estate include royalties, rentals, and fees. In Fiscal Year 1983-84, these revenues amounted to $4.2 million, or 13.5 percent of all income received by the Trust during this period. Industrial minerals, led by sand and gravel, contributed $1.1 million from 82 active properties.

Jan 1, 1987

By Thomas M. Goodell, Timothy D. Arnold

Dilute-phase pneumatic conveying has been used in the mining industry since the 1920s. It has primarily been used for the hoisting of coal and salt ores, and as a transportation medium for backfill material. More recently there have been investigations into a wider variety of applications, which this paper addreses. The paper will point out some deficiencies in the system. It 1s not the "champion" of the mining industry, but rather an excellent srste?1 with a variety of applications that may not have been studied m enough detail. The most imaginative applications to the Redpath Pneumatic Conveying System have been initiated by persons needing an innovative application to a specific predicament.

Jan 1, 1992

By Y. David

In 1990, the United States became only the second country (after China) to produce more than 900 Mt (1 billion st) of coal in a single year. US production of bituminous and subbituminous coal, lignite and anthracite totaled 933.5 Mt (1.029 billion st) in 1990, 5% more than in 1989. The production gains were largely due to the rebuilding of depleted coal stockpiles by electric utilities and a surge in US coal exports. Domestic coal consumption essentially remained at its 1989 level. A slight increase in electric utility coal consumption was partly offset by a decline in metallurgical coal use. The use of coal in other industries and in the residential-commercial sector remained virtually flat.

Jan 1, 1991

By James Y. Oldshue, Paul M. Kubera

Ore processing requirements in the gold industry are similar to those in other sectors of the minerals industry. In all cases, the processes revolve around the handling of large volumes of ore slurry, incorporating either physical processing or chemical processing steps which are related to distinct mixing application classes as defined in Table 1. From this standpoint, the complexity of the applications range from the simple (blending, solid suspension, etc.) to the complex (e.g., multi-phase reactor systems). The large volume of material to be processed dictates the large equipment size which is characteristic of this industry, and the often remote locations place a premium on both mechanical and process reliability.

Jan 1, 1992

By Peter J. Alderson, M. P. Evans

The application of conveyor belting in bulk materials handling is crucial to the success of most mining enterprise selection of the cover rubber grade and thickness has a direct bearing on the cost per ton conveyed. Current and future demands placed on belt covers by higher speeds, increase capacities and greater lifts means today's cover will not be adequate for tomorrow's applications. The simple selections of RMA Grade I and I1 and MSHA above and below ground need to be expanded upon. This paper describes various new approaches for selecting conveyor belt covers for specific applications. It also presents examples of material and compounding techniques available to the belt manufacturer to improve the performance of their covers.

Jan 1, 1996

By Thomas Pollard

It is truly remarkable how the image of longwall as a method of mining has changed. Between 1920 and 19609 viewed on a world wide basis, longwall was regarded as a' system for difficult and deep conditions and associated with intensive labour extraction. Today the world looks on longwall in the hope that it can produce the next really big break through in productivity, Three correlated machinery developments have made this possible, but it is not only the machinery developments, interesting though these be in themselves, but together with developments in control systems of these machines that longwall now looks so much more attractive, The machinery concerned is, of courses:- 1. The Anderton Shearer Loader - A miner that takes a narrow strip off the, face at rates acceptable to modern mining engineers. 2. An Armoured Flexible, Conveyor which can be kept in close contact with the face and still convey coal as it is snaked over to the faces 3. Powered support systems which can be mechanised and controlled with reliability at any distance from the individual support itself.

Jan 1, 1964

By E. R. Hendrickson

About 1/3 of the world's supply of phosphate rock is produced in a relatively small area of the Florida peninsula east of Tampa. Until this past year, a circle with a radius of about 25 miles and centered on Bartow would encompass the major producing areas. During the past year producing areas have opened in North Florida which promise to vie with the Polk-Hillsborough County area in terms of proven reserves. In addition, new phosphate production is planned for counties to the south and west of the present fields. From the existing production areas, however, more than 19 million long tons of phosphate were mined in 1965. As mining engineers most of you probably are familiar with the methods of mining and beneficiating the pebble phosphate rock. You thus recognize that, although some water quality problems may arise from these processes, there is no potential air pollution problem. To make an economically useful product, however, further processing must take place. It is from this additional processing that potentially damaging materials may be discharged to the atmosphere.

Jan 1, 1966