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By David S. Smith

Almost nine years after the assertion of enormous and pervasive federal control over coal mines by means of the Federal Coal Mine Safety and Health Act of 1969, 30 USC Section 801 et seq, as amended by the Federal Mine Safety and Health Act of 1977 (which basically increases the punitive powers of government) a brief assessment of some of the underlying causes, present status, and possible alternatives to governmental control is appropriate. In a governmental system based upon the principles of democracy and the protection of individual freedoms and constitutional rights the ultimate mechanism for abrogation of these rights is the creation and exploitation of fear. Machiavelli in rendering advice concerning the power over men provided by fear stated, "... it is much safer to be feared than loved .. fear preserves (the government) by a dread of punishment which never fails." The Prince. Within the context of the assumption of control by the government over industries or segments of our population - popular fear provides a convenient and almost necessary mechanism for the avoidance by law or regulation of democratic principles. The popular fear of coal mines has been successfully exploited by various goal oriented groups in the past and most recently by a Congressional constituency with a vested interest in controlling the mines through regulation.

Jan 1, 1979

By I. Iwasaki

The presence of calcium ion in iron ore pulps causes heterocoagulation of montmrillonite on hematite leading to indiscriminate dispersion. Two methods were investigated to control the adverse effect of montmorillonite: chemical method using such complexing agents as EDTA and sodium tripolyphosphate, and mechanical method involving ultrasonic treatment. Their roles in controlling the adverse effect were investigated by zeta potential measurements, starch adsorption tests, and flocculation and selective flocculation tests.

Jan 1, 1986

By Hamid Maleki

A geotechnical monitoring program has been implemented at Energy West Mining Company for enhancing site-specific evaluation of longwall stress conditions. This program consists of underground measurements at five locations in two neighboring mining districts located in the Hiawatha and Blind Canyon Coal Seams under moderate to deep cover. Within the last five years, additional measurements, including data on recorded seismic events and face conditions, have been incorporated into the data collection program together with detailed geologic mapping of longwall gateroads. In conjunction with the measurement program, the authors have completed detailed boundary-element stress analyses of the mine plans. Models have been calibrated using the data from in-mine instrumentations and then routinely used for evaluation of mine plans at depths approaching 2,600-ft. The work has improved our understanding of load transfer, seismicity and yield pillar performance. It has identified areas of potential increased stress levels at certain longwall face positions and provided guidance to measures that could be considered to mitigate the potential for these increased stress levels.

Jan 1, 2009

By Jorgen Elbrond

Shovels, trucks and repair bays for the trucks each play their role in the capacity of an open pit operation. It is therefore convenient to have a procedure for the capacity calculation which takes all 3 factors into consideration in a comprehensive manner. This can be done by means of a cycle model, earlier developed for the shovel-dumper circuits, when the repair facility with its number of repair bays is added as a superimposed service system, which the trucks visit at certain specified intervals. The calculation model transforms the mechanical availability of the trucks into their operational availability. The system's capacity in truckloads per shift and the trucks' operational availability of certain combinations of shovels, trucks and repair bays are shown.

Jan 1, 1981

By Ronald E. Yarbrough

As a result of concern for the citizens of the State of Illinois who owned structures above underground mine workings, the Illinois State Legislature passed House Bill 158 in 1978. This bill amends the Illinois lnsurance Code and creates the Mine Subsidence Reinsurance Fund which is an insurance pool that is to receive a state appropriation of $500,000 as "start-up" money. One hundred thousand dollars has been paid to the fund as of October, 1982. The Fund is to return this appropriation to the State and is to remain self-supporting from premiums. The Fund utilized a pre-existing institution, which also was an insurance pool, the "Fair Plan Facility" and its governing Board, consisting primarily of insurance executives, to administer the program. The Mine Subsidence lnsurance Act went into effect October 1, 1979, and the bill provides that property owners in the State of Illinois may purchase up to $50,000 of mine subsidence insurance which is attached to their fire insurance policy. The deductible is normally 2%, but cannot be less than $250 or more than $500. The annual rate structure for residential structures in 1981 for $50,000 coverage is $10 (frame), and $12 (masonry). The rate structure for commercial buildings is based on the value of the building and the rates for $50,000 maximum coverage is adjusted upward. The insurance was mandated by the State Department of lnsurance and rolled onto the insurance policies of the homeowners in 34 counties which had been recognized as having sufficient exposure to subsidence damage to be covered by the Act. One percent or more of the land surface is undermined in each of the 34 counties. In the other counties undermined in the State of Illinois, insurance is available to the homeowner upon request to the private insurance carrier.

Jan 1, 1982

By Brij M. Moudgil

Flotation was introduced in phosphate rock processing in the late twenties and since then it has been an important part of the concentration process. More than two thirds of the rock produced in Florida is upgraded by the flotation process. Since no crushing or milling steps are involved in the material preparation, the flotation plant feed is coarser than in most other mineral flotation systems. During hydraulic processing of the rock, particles in the size range of -14, +150 mesh constitute the flotation feed. This size fraction is further classified by hydraulic sizers, stationary screens and vibrating screens into a coarse (-14, +35 mesh) and a fine (-35, +150 mesh) flotation feed. The flotation techniques for concentrating the fine feed as practiced by the Florida Phosphate producers have been standardized over the years, however, methods for upgrading the coarse feed differ from plant to plant. In this paper an effort has been made to present relative merits of the techniques employed for concentrating the coarse phosphate rock..

Jan 1, 1977

By M. M. Botz

Cyanidation tailings which are disposed in a surface impoundment experience a loss of cyanide due to natural degradation, frequently reducing the cyanide concentration to very low levels. Quantifying cyanide losses in terms of pond geometry, local weather conditions and feed solution chemistry has been largely empirical though in many cases mining operations rely on surface impoundments to reduce cyanide to below an internally regulated concentration or an effluent limitation. To permit a more quantitative evaluation of cyanide losses in an impoundment, a computer simulation was developed to estimate the losses of free, WAD and total cyanide due to dissociation, photolysis and volatilization. Results of the model are compared against data collected for a North American tailings impoundment during 1998.

Jan 1, 1999

By L. W. Teal

The Paupers Dream Property is located in the northern Boulder Mountains, southwestern Montana, 30 km southwest of Helena. The property is situated in the central portion of the Butte-Helena gold belt, a NE trending lineament marking a zone of recurrent, late-Cretaceous to mid-Tertiary volcanic activity. Geology consists of a plutonic basement of late-Cretaceous quartz monzonite overlain by a pre-volcanic basal conglomerate and a complex sequence of Oligocene rhyolitic volcanics. Gold mineralization occurs in fracture-controlled quartz veins, silicified stockwork, and brecciated shear zones as auriferous pyrite, arsenopyrite, and disseminated free gold. An estimated 60,000 tonnes averaging 2.5 g/t was produced from the Porphyry Dike, Venus, and Paupers Dream Mines on the property. Current drill indicated reserves (May, 19861 are placed at 6,946,000 tonnes averaging 1.45 g/t gold.

Jan 1, 1987

By William Wargo

The basic reason for lining underground cavities is to keep the cavity open during its useful life by providing adequately for the support of the surrounding rock and for the necessary degree of water tightness. This covers the entire field of support methods from the simpliest timber support to reinforced concrete in all its variations as applied to tunnels, galleries or shafts. The problem involved in the design of more efficient and economical lining systems for even bigger cavities has been magnified by increased speed of advance made possible by better blasting tecniques, improved tunneling machines and more efficient material handling. Tunnel lining today requires a disproportionate amount of time and money compared to other operations mostly due to the manuel labor involved in its installation. One solution to this problem is the developement of an entirely new concept in tunnel lining designed notoonly to overcome this bottleneck but also to open up the field for further increases in speed of advance. This new lining system acts first as a fast protective armour then becomes the concrete metal form and ends up as reinforcement sheet inside the concrete lining. This system developed and manufactured by Bernold A. G. of Switzerland since October 1968 has been installed in 25 applications in Europe under all ground conditions from stable rock to unconsolidated ground.

Jan 1, 1970

By B. V. Driga

The paper presents the evaluation method of the thermal power potential of the salt lakes developed in collapsed salt mines in Romania. It is well-known that the hydro-chemical stratification of these lakes favors warmer internal layers. The degree of heat varies during the year, but, taking into account the large number of genetic lakes of this type, it can be used as a local utilizable power source. The authors analyze the correlations between the physico-chemical parameters of the water and the degree of heat stored as a function of the morphological parameters of the lakes, as well as the technical parameters for capitalizing on this power.

Jan 1, 2008

By Bruce C. Trent

The need for effectively evaluating the potential for surface subsidence due to under- ground mining has been widely documented. As the emphasis within the coal mining industry changes to reflect the increasing demand of this resource, the potential for damage due to differential surface subsidence will certainly become more acute. The present state-of-the-art of predicting ground motion due to underground excavations is, at best, primitive when one considers the immense complexity of possible geological inter- actions. For the most part predictions have been limited to empirical evaluations based upon earlier case histories. While the tools of the subsidence engineer are limited, they are important and serve to provide reasonable bounds for possible ground motion. As underground mining becomes more extensive, however, there will be many instances where excessive subsidence will be most undesirable and yet there may be few, if any, case histories similar to the operation in question.

Jan 1, 1982

By William H. Bird

Over the past 14 years, the efforts of 2 companies and several individuals have outlined a major solfataric gold ore body in the Summitville district in the southeast San Juan Mountains of Colorado. The hard work of these years could not have flowered without a dedication to modern exploration methods, an intense interest in new theories of ore genesis, and a relentless discontent with the accepted geology of the Summitville area. To set the stage for this discovery period, it must be noted that it began 100 years after gold was first found at Summitville. It was the height of the "porphyry copper" era and gold was still not a part of the explorationists' portfolio. It was also a time of great intellectual stimulation. Theories were rapidly developing to relate different types of ore deposition and to place ore genesis within the fabric of plate tectonics. Summitville itself had just been linked to the newly discovered Platoro caldera complex and the Platoro lineament. This in turn related Summitville to the other San Juan volcanic field caldera ore deposits.

Jan 1, 1990

By Harold L. Hinds

The refining of precious metals from steel wool cathoodes is completed by one of two methods: 1) By direct fire smelting or: 2) Acid treatment of the cathodes to dissolve the steel wool and then followed by fire smelting. To further the refining of the cathodes, the Miller Process and the Wohlwill Process are used.

Jan 1, 1981

By Alfred A. Roetzer

In several sections of the country new demands are being brought bar cement users. Among these the demand' for truck shipments; and palletized loads present new problems that do not lend themselves to sample solution. In fact these demands have far-reaching effect in the way bagged cement might be marketed. Early solutions of palletized truck loads filled from existing packing and loading facilities have resulted in' slowdown in packing, additional labor and space for palletizing, considerable experimentation in type and construction of pallets, and usually far from optimum truck handling and loading methods.

Jan 1, 1961

By Wilbur C. (Original by) Helt

Throughout the history of mankind, the principal use of coal has been to produce heat through combustion. The heat is used in many ways: to warm air space for our comfort; to provide heat or energy to power industrial processes, such as cement and steel production; and to produce electricity. Because it is our nation's most abundant fossil energy fuel, coal in the late 20th century is on the threshold of becoming a significant source for synthetic liquids and gas energy fuels for this country. This is made possible by conversion processes which can change solid coal into various synthetic gases and liquids. These coal-derived fuels are nearly identical to the processed fuels and chemicals provided by natural gas and crude oils, which presently provide almost all the petrochemical feedstocks and energy fuels needed for the residential, light commercial, and transportation markets. A revolution is beginning to take place, not only in the United States, but in many other countries with a return to a coal-based energy economy. Also, new combustion and conversion technologies which are compatible with national health and environmental goals are rapidly emerging. These technologies will allow coal's use to be expanded not only in its traditional markets, but also to supply markets held by natural gas and crude oil. With the worldwide decline in natural gas and crude oil reserves, coal is being-looked upon to meet the energy demand. Because of these new coal conversion technologies, coal will no longer be only a combustion fuel, but a valuable raw material for production of a variety of clean fuels and chemicals.

Jan 1, 1981

By A. V. Castelli

Weighting materials as we know them today were first recognized in 1922 by B. K. Stroud1. Stroud, who was supervisor or the Mineral Division of the Louisiana Department of Conservation, tested galena, cement and hematite as weighting materials and successfully used hematite to make a "heavy mud". The first use of barite was in the fall of 19222 . The process of adding heavy minerals in mud was patented in 1926 by Stroud and National Pigments and Chemical Company, a subsidiary of National Lead Company now NL Industries, Inc. The ground barite was marketed as BAROIDR barite.

Jan 1, 1983

By James W. Cooksley

This report concerns a seismic geophysical exploration program which was conducted 3 miles southeast of the Carlin Mine, in Lander County, about 18 miles north of Carlin, Nevada. A twelve-fold reflection seismic line was executed over a one-mile traverse in section 32, Township 35 North, Range 51 East. This study is part of an exploration pro- gram directed toward finding Carlin-type gold deposits which are concealed under younger alluvium and volcanics. The exploration objectives of this program are as follows: 1) measure the thickness of the younger, sedimentary and volcanic deposits which overlie the "productive rock sequence", 2) delineate the Roberts Mountains thrust fault, 3) investigate the origin of the geochemical anomalies present in the western portion of section 32.

Jan 1, 1985

By A. G. Oppegaard

Most iron ores treated by the R-N direct reduction process yield metallic iron products considerably lower in titanium, manganese, and chromium oxides and alkaline metal sulfates/sulfides than were contained in the original ores. These metallic iron products are suitable as feed stock for the open hearth and electric steel-making furnaces. The elements which are rejected in part are acceptable in the product since the product is designed to by-pass the blast furnace. R-N reduction conditions (PCO+H2-1 atmosphere, 1830° to 2150° F.) are adjusted for each ore. The iron ore which is reduced to 90 to 95 percent metallic iron is then subjected to the conventional beneficiation techniques. Under these conditions, 55 to 80 percent of titanium oxides, 75 to 95 percent of manganese oxides, 60 to 90 percent of chromium oxides and up to 97 percent of alkaline metal sulfates contained in the ore are rejected with the gangue to the non- magnetic tailings. The metallic iron products illustrated in this work contained 89 to 96 percent total iron, one to five percent TiO2, 0.2 to one percent MnO, 0.3 to 1.6 percent Cr2O3 and/or up to one percent alkaline metal sulfide. Usually only one of these components was present. Recoveries ranged from 80 to 96 percent of the iron in ore.

Jan 1, 1958

By Carson Sharp Beltch

The determination of aqueous cyanide is accomplished by either detection in the sample as collected or by removal of the cyanide of the collected sample, followed by detection. The direct determination of the cyanide content of a solution can only be used in the simplest of systems, since many interferences can result in errors. Thus the most widely used method for total cyanide determination involve the reflux distillation of the sample using heat, acid and vacuum or air flow. The basic theory underlying this analytical approach is that by reducing the pH, the quality of molecular hydrogen cyanide will be in- creased and can be removed from the solution by elevating the temperature. The hydrogen cyanide is then collected in a caustic solution and analyzed. The general approach of removing the cyanide from the sample by distillation represented a major advance in this area of analytical chemistry. It enabled the determination of cyanide in many additional types of samples. When it became apparent that the tightly bonded cyanide complexes were not being detected by this approach, many methods fox complex ion destruction were proposed. These methods usually involved low pH adjustment with oxidizing mineral acids, coupled with the catalytic decomposition of the tightly hound complexes. All off the complexes except the strongest could he broken by these methods. The catalytic reflux distillation step has been found to have some negative aspects, since many materials that can be distilled with hydrogen cyanide will interfere with the color development step and result in a false positive reading.

Jan 1, 1981

By John H. White

As production of ground limestone increased our Company found it had an enviromental problem with limestone dust from our hammer mills. With the quarry and processing plant situated within 1 klm of a small township of 5000 people dust collection became essential. Regulations under the Clean Air Act 1972 also had to be complied with. Prior to this any demand for lime flour had been met by the use of a small drier and ball mill. Both expensive to operate. Dust emitting from the mills would amount to over 4000 tonnes per year. The cost savings were obvious. We had a better product which was essentially a by-product. Faced with a surplus of a very useful, but difficult product to handle we considered the possibility of disposing of it on the agricultural market.

Jan 1, 1982