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By James R. Oehler

Progress, future challenges, and the continual search for more efficient and rapid methods of excavating underground openings and shafts were main themes at the 1983 Rapid Excavation and Tunneling Conference (RETC) held June 12-16 in Chicago, IL. The event, jointly sponsored by the Society of Mining Engineers, the American Society of Civil Engineers, the Canadian Institute of Mining and Metallurgy, and the Engineering Institute of Canada, offered a diverse program for both civil and mining engineering disciplines. Although all papers given at the three-day conference were noteworthy contributions, and each is included in the conference proceedings currently available from SME, there were a few sessions that had particular mining-related interest. Research, Acceptance Needed for Water-Jet Technology Water-jet-assisted rock excavation is seen by some as a technology moving from the prototype phase to a fully developed, accepted system within the next decade. For an industry that is traditionally fairly slow in accepting significant changes, this development appears especially noteworthy. However, speakers at the water-jet technology session generally agreed that many large US manufacturers are not viewing water-jet-assisted equipment as viable replacements for all-mechanical systems. This, they fear, may mean some US manufacturers will lose a significant share of certain equipment markets to foreign competitors who are moving aggressively ahead in this area. Despite the advantages of increased cutting rates, reduced power requirements, less dust, prolonged bit life, and reduced sparking in many cutting situations, water-jet technology applied to mining is apparently having some acceptance problems in the US. R. J. Evans, professor of industrial engineering at the University of Pittsburgh, noted that there are several perceptual barriers to water-jet coal cutting; such as uncertainties concerning the fu¬ture demand for coal and the reliability of equipment, apprehensions that jet-assisted equipment will make the mine operator dependent on specific types of hard-to-obtain equipment, and fears about accessibility of the equipment for repairs. Evans also said numerous parameters need defining before taking advantage of water-jet-assisted cutting systems in under-ground coal mining in the US. For the cutting head, information must be obtained on optimum bit geometry and spacing, and maximum and minimum torque requirements. For a complete US water-jet cutting system, Evans added, research is needed to establish optimum jet pressures, jet powers, number of jets per bit, and location of jets relative to the bit. One research project making progress towards optimizing parameters for a water-jet-assisted drag bit cutting system for coal mining was described by Levant Ozdemir, director of the Earth Me- .

Jan 8, 1983

By Brenda J. Morrison

Anything to do with radioactive waste disposal in these days is regarded in a very negative light and with the thought that no possible good could come of anything connected with it. However, it should be remembered that the Austrian government's disposal of some tailings from the Joachimsthal mines resulted in what was probably the most important scientific discovery of this century. In 1898 the Austrian government agreed to give a Polish research assistant working at the School of Physics in Paris one ton of tailings to enable her to carry on her research. Her meagre stipend and the lack of a research grant did not allow her to purchase the ore which was relatively expensive. The uranium oxide in it being used to colour the famous Czechoslovakian glassware. As we all know, from this ton of ore Marie Curie by her own physical labours extracted one gram of radium. When she started this research she was pregnant with her first child. Nothing of course was known at the time about the biological effects of radiation. Very shortly, of course, the acute effects such as skin burns were observed but it was some years before the chronic effects were noted. It is impossible to estimate to what cumulative amount of radiation that Marie, Pierre and their daughter Irene were exposed but it must have been enormous and it took its toll. Marie complained for many years of fatigue and exhaustion and at one point she was seriously ill with some kidney problem which was probably due to toxic effects of ingestion of uranium. She lived until she was 67, however, and died of leukemia. Her eldest child, Irene, who carried on her work, did not live as long; she died of leukemia at 57. The other daughter, Eve, related how her mother and she went on a skiing holiday not many years before her death, and how her mother at this time would swim 300 meters at a stretch. (Curie, 1937). This suppleness of limb could have been due to the anti-inflammatory action of radiation. Even today, patients in France with certain types of rheumatic conditions are treated with injections of radium, where other anti-inflammatory drugs such as aspirin or cortisone have not worked. (Bertrand, Legras and Martin). All this anecdotal information is just to point out that it is an ill wind that blows no good. The risks connected with uranium waste disposal and tailings piles are

Jan 1, 1980

By Searl. Milton F.

Introduction The urgency of further development of our domestic energy resources becomes more apparent every day. The production capability of existing facilities, taken in the aggregate, declines perhaps 10% per year; imported energy is expensive if available at all; conservation helps reduce demand but eventually will reach a point of diminishing return; new energy sources are promising but past experience, as with nuclear power, teaches us lead times are long and success is not assured. To approach the energy future rationally, it is essential to have some idea of the size of the nation's remaining energy resources, their characteristics, and the degree of uncertainty involved in their estimates. Resources are, of course, only one end of a long chain leading to energy supply to the ultimate consumer. They are an essential element, however, and the only one not under society's control. Given that the resources and a national will to produce the energy exist, it is possible to convert the resources to supply in, generally, an environmentally reasonable manner. However, the process of developing supply takes time. Government must permit access to the resource, and remunerative prices and further evolution of technology are required. This paper does not deal with these essentials, but they must not be forgotten. This discussion is limited to coal, oil, natural gas and gas liquids, uranium, and oil shale. Other energy sources are discussed elsewhere in this issue. Crude Oil Conventional crude oil resources are of greatest concern today, given our dependence on imported oil and its rapidly rising price. Estimates of oil originally in place (OOIP) range from 619 billion bbl to 1,094 billion bbl, differing by almost a factor of two (Table 1). This is surprising because the U.S. is a mature petroleum province with over 120 billion bbl produced and over 400 billion bbl OOIP discovered. Differences in the estimates involve differences in the experience of the various estimators, the interpretation of present geologic information and historical statistics, the methodology, and probably the extent (i.e., water depths) for which offshore resources are included. The range shown for the estimate of a given estimator appears to be primarily due to geologic uncertainty. This uncertainty can be measured by taking the ratio of the low and of the high estimate to the expected estimate for that information source. The low estimates range from 0.85 to 0.87 of their respective values. The high estimates range from 1.18 to 1.27 of the expected values. In all cases the high estimate is further from the expected value than the low,

Jan 9, 1980

By L. A. Taylor

The production of oxygen on the Moon utilizing indigenous materials is paramount to a successful lunar colonization. And several processes have been put forth to accomplish this. The LLOX generation schemes which have received the most study to date are those involving?: 1) the reduction of ilmenite (FeTi03) by H2, C, CO, CH4, CO-CI2, & Cl2 plasma, 2) magma electrolysis, both unadulterated and fluoride-fluxed, and 3) several others, including carbo-chlorination, HF acid leaching, fluorine extraction, magma oxidation, and vapor pyrolysis. The H2 reductions of ilmenite and magma electrolysis processes have received the most study to date. They are both feasible schemes with various pros and cons, including their feedstock requirements. However, all processes should be addressed at least at the onset of our considerations. There is an obvious need for considerably more experimentation and study. Some of these requisite studies are in progress, and this paper reviews several of the most studied and feasible processes for winning oxygen from lunar materials.

Jan 1, 1991

By Fan Yang, Meigui Yi, Lan Xiang, Zhuoying Yang

This paper reported the calculation of the reaction heat in titanium-bearing blast furnace slag (abbreviated as TBFS)-H2SO4 system based on estimation of thermodynamic data of CaTiAl2O6 by mechanical mixture model. The thermodynamic analysis indicated that CaTiAl2O6 was more stable than the corresponding ternary oxides as CaO·TiO2, CaO·Al2O3, and Al2O3·TiO2. TBFS-H2SO4 system was highly exothermic since all of the reactions involved in the system were exothermic. For example, the increase of temperature from 25 to 200°C led to the increase of the release of the reaction heat in TBFS (100.0g)-H2SO4 system from 181.28 to 189.73kJ. Eighty-five to 90%of the reaction heat in TBFS-H2SO4 system was contributed by the reactions among CaTiAl2O6, CaTiO3, CaMgSi2O6, and H2SO4.

Feb 1, 2021

Large variations of coal seam thickness and roof conditions are associated with the occurrence of mine floor undulation at Shoal Creek Mine, operated by Drummond Company, Inc.. Ground control problems, such as roof falls and face failures along with extremely high shield pressure and rapid face convergence, are often reported at the longwall face when these undulations exist. This greatly increases equipment downtime and causes production delays. As a result. a comprehensive study of mine geology including roof conditions and longwall performance were conducted in the mine. With the help of continuous full-face shield pressure monitoring using the Longwall Strata Control and Maintenance System (LoSCoMS), a large data base of shield pressure with various roof conditions has been established. This enables the mine operators to accurately evaluate the roof behavior and shield performance and to take the appropriate operational steps at the face to reduce the number of downtime and face failures. This paper summarizes all works and findings from the study including detailed roof geology and its effect on longwall performance.

Jan 1, 1998

By Donald M. Keagy

How many times have you said or heard someone say, 'What are you doing right now?" And how many times have you heard the reply, "Breathing air!" Probably never, or at most only a few times in a facetious vein. Breathing air is absolutely necessary to sustain human life, and yet most of us take it completely for granted. Beginning ten to fifteen years ago there was growing concern on the part of the general public that pollution of the air is a threat to man's health and welfare. Concurrently much thought and effort was devoted to the task of defining and resolving the problem of air pollution. In the course of this effort it has become quite clear that our National policy in this regard should be founded upon three basic axioms: (1) Action should not be postponed until emergency conditions make it compulsory; (2) The air cannot be purified after it is polluted, and (3) Air pollution control cannot be accomplished without close cooperation among all levels of government, industry, and the public.

Jan 1, 1967

By M. Shahsavar, J. Sattarvand, J. Gomez

Mining can be categorized as a hazardous activity, considering some factors such as environmental conditions with a considerable presence of humidity, suspended particles, or falling rocks have affected the severity and number of accidents compared with other economic sectors. The industry analyzes incident reports to narrow the rate of severe injuries and fatalities, conducting root cause analysis and identifying leading indicators. As the International Council on Mining and Metals noted, the vast trove of incident data is not analyzed as much as possible due to a lack of analytics expertise at mine sites. However, machine learning could solve the problem of analyzing all the incident data in a no-timeconsuming way, considering the abundant data, and without using expert personnel in data science. Thus, a Convolutional Neural Network and a Naïve Bayes model were introduced to perform classification in the MSHA database. The database from 2020 consists of 60 fields to describe safety incidents; these fields include mine I.D., accident date, subunit (mill, surface), material extracted, and other metadata.

Jun 25, 2023

By Kefton H. Teague

Olivine was first described and named by Warner in 1790. It is an olive green to greenish gray colored magnesium-iron silicate containing a mixture, in solid solution, of fosterite (Mg2SiO4) and fayalite (Fe2SiO4). Ratios between fosterite and fayalite in olivine are somewhat variable, but in general olivine contains at least 85% fosterite. Specific gravity is variable also, depending on the ratios of fosterite to fayalite. As a rule it is in the 3.2 - 3.4 range. All commercial olivine is obtained from the rock dunite, the most basic member of the peridotite group. Dunites, in addition to being composed primarily of olivine, generally contain assessory pyroxenes and spinels (chromite and magnetite). Dunites', when altered by hydrothermal solutions or metamorphism, often contain alteration minerals such as talc, serpentine, chlorite, vermiculite and amphiboles. In the 1930's and 40's considerable research was conducted on olivine for use as a refractory, plant food raw material, magnesium source for metal, and a source for magnesium chemicals. This research met with only limited success.

Jan 1, 1977

By Y. J. Wang

The definitions of system pressure loss (mine head) and system resistance, which are traditionally associated with single-fan net- works, are applied to multiple-fan ventilation networks. The system characteristics -- relations among air power, pressure loss, air quantity and resistance -- are analyzed by introducing the concept of subsystems. These subsystems are associated with the fans located in a cutset of the network. For a multiple-fan network, the resistances for the subsystems and total system are dependent on the quantity ratios of the subsystems. In general the pressure loss of a subsystem or a total system does not vary as the square of the corresponding air quantity. If the quantity ratios of subsystems are all held constant, then the resistances become constant and the pressure losses are predictable from the quantities employing the "square law." The system resistance has a minimum value under the natural- splitting flow pattern. Being independent of the value of system quantity, the minimum system resistance provides a basis for comparing the different networks.

Jan 1, 1983

By V. D. Hanson

When maintenance of a plant or operation is under discussion immediately three "M's", all in short supply, are brought to mind - money, men and markets. This paper will present what currently is being done at our plants and its effect on the 3 "M's". Examination of coal realization figures (F.O.B. Mine) from 1945 to the present reveals the fact that open and free competition can and will meet market conditions. The industry, without benefit of advantages afforded tax and transportation wise to oil and gas, remains the backbone of the energy market of United States. Figure No. 1 shows the realization figures from 1945 through 1962 compared to the hourly earnings. Note that through 1945 to 1948 F.O.B. prices increased $1.93 per ton while hourly earnings increased $.66 per hour. Since 1948 (with the ex¬ception of 1957) F.O.B. prices have declined $.45/ton, while hourly earnings have increased $1.23 per hour. Basically the maintenance men possibly represent the highest increment rate in the overall hourly earning.

Jan 1, 1963

By D. A. Meyer

The long and arduous process of bringing aggregate produced in Mexico to the Gulf Coast of the United States really began in the 1970s when the first exploratory trips were taken by Vulcan's geologists. It was not until the middle of the 1980s that all of the elements of the project seemed favorable and the largest capital investment in Vulcan's history was given the green light. The history of the project will be covered along with a discussion of the role that market forecasting played in the process. Is this the first of many or a once in a lifetime project? In July 1987, Vulcan and its joint venture partner broke ground in Mexico for a world-class limestone quarry and crushed stone production facility. This project is the largest ever undertaken by Vulcan's Construction Materials Group, with a total cost of over 200 million dollars -a cost shared equally by Vulcan and its joint venture partner, Ingenieros Civiles Associados, or ICA, a diversified Mexican company which is also the largest construction firm in Latin America.

Jan 1, 1995

By M. E. Mellado

In this paper, we present an a posteriori validation of a heap leaching analytical model using sensitivity analysis. The model is suitable to represent the process of heap leaching of solid reactants from porous pellets and is based on a combination of the leaching kinetics at two levels: particle and heap. The validation is simple, and a sensitivity analysis can easily be performed. The simplicity of the analysis provides insight into the control and optimization of the heap leaching process without strong mathematical complexities. The model and the corresponding sensitivity analysis include the effects of heap height, particle sizes, flow rates and several operation-design variables. Using a case study, we discuss the importance of model validation based on sensitivity analysis. We also comment on several choices for optimizing the process. We had three goals in this work: a posteriori validation, highlighting the importance of model validation and providing insight into optimization choices. We can conclude that the model has good internal logic and there are no extra variables; i.e., all of the variables in the model are necessary.

May 1, 2012

By John K. Hammes

This paper has been written as one of a group of papers dealing with the subject "Cost Elements in Mining". What are cost elements in mining? The mine operator thinks of direct mining costs in terms of labor, materials, supplies and power, and we might define cost more generally as the price paid to acquire or produce something. Economic theory also has its concepts of cost. From one point of view, that of the consumer, the cost of mineral commodities might be viewed as the total price industry pays for mine output. Similarly, the mining company engaged in the on-going business of finding, developing and operating new mines is concerned very much today with the distribution of all the revenue paid for mine output and not just with its direct or controllable cash costs. In other words, what will the labor force, the supplier of energy, explosives, and reagents, and the supplier of government services, management, capital and the ore reserves receive for their contribution to production.

Jan 1, 1974

By G. A. Gunderson

Since our time is very limited, I would like to relate to you as best as I can a few important areas that I think may be helpful. 1.) The Real Difference between Dense Phase and Dilute Phase Pneumatic Conveying: Within the many variations of so called Dense Phase conveying, it is often difficult to determine to what degree a system is Dense Phase or if, in fact, it is a Dense Phase system at all. A system that appears and is generally known to be Dense Phase can under certain operating conditions perform as a Dilute Phase system. If, for instance, a high pressure system, which is generally a Dense Phase system, operates at 60 PSIG, say 4 atmospheres, utilizes enough air volume, the conveying velocity will easily exceed the normal design velocity of a typical Dilute Phase system. Now, on the other hand, a low pressure system which we will term a Dilute Phase system, operating at 15 PSIG; say 1 atmosphere, can convey a given product at well below the saltation velocity, like a Dense Phase system.

Jan 1, 1977

By W. F. Moll

Absorbent clays are products, usually in the form of granules, that can absorb and hold approximately their own weight of liquids while essentially maintaining their size and integrity. They always contain in abundance at least one of three materials: montmorillonite, attapulgite and diatomite. The first two are complex silicates; the last is amorphous silica of biogenic origin. Not all montmorillonites provide the base for an absorbent clay, however. Nevertheless, the silicates in particular, and the diatomite to a lesser degree, have certain molecular properties that give rise to the useful physical properties. Uses Use of absorbent clays is as old as civilization. Numerous references to "fuller's earth" appear in ancient writings, including the Bible. Fuller's earth originally connated a clay that could absorb oil and grease from wool to facilitate cleaning. Robertson (1986) covers the fascinating history in interesting detail. In the modern sense, absorbent clays find application in three principal areas, and a host of minor ones. Industrial floor absorbents, cat litter and agricultural carriers comprise the major uses.

Jan 1, 1986

By Niles E. Grosvenor

Several methods have been proposed for determining the tensile strength of rock. These have been tried out over the past several years, but the results have been erratic and of doubtful value. The tensile strength of rock is its weakest property, and this property apparently enters into all failure phenomena whether underground or on the slope of an open pit. Therefore, it is essential that detailed quantitative information is known about the tensile strength of rock if the design engineer is going to select the proper pit' slope, pit orientation, or orientation of underground workings so as to give the most economical and safest mining condition. This quantitative information may be used to orient the pit in such a manner as to allow steep slopes along two sides. This information may possibly be used to orient the direction of either underground workings or open pits so as to decrease powder consumption and to increase blasting efficiency. Hence it is of prime importance that a method of determining accurately the tensile strength of rocks be developed.

Jan 1, 1960

By E. J. Owen, A. Appah, I. C. Sanchez, K. T. Stafford, N. Hurtig, R. Otoo, N. A. Iverson, S. A. Moses, V. T. McLemore

New Mexico lies at the eastern edge of one of the world’s great metal-bearing provinces hosting numerous Laramide and Paleogene mineral deposits. Southwestern New Mexico contains Laramide porphyry Cu (±Mo, Au) and Paleogene Mo-W deposits. Porphyry deposits are generally large, low-grade deposits containing Cu, Fe, Mo, Au sulfides (and other metal sulfides) associated with porphyritic intrusions and exhibit characteristic alteration styles. Porphyry deposits can also be spatially and temporally associated with skarn deposits and polymetallic veins. All of these deposits have the potential to host various critical minerals, including Cu, Zn, Bi, Co, Ni, rare earth elements (REE), Te, and W. Critical minerals may be found as substitutions within ore minerals or as separate mineral phases. These deposits are constrained using 40Ar/39Ar dating into three ore-producing magmatic pulses: 1) ~78–71 Ma Laramide pulse, 2) ~59–50 Ma, Laramide pulse, and 3) ~40–30 Ma Paleogene pulse. New and historic whole-rock geochemical data have highlighted areas with critical minerals potential that require further study.

Feb 1, 2025

By Ray W. Ballmer

Historically, Bingham is a rail pit, starting with steam locomotives in 1906 and converting to electric locomotives in 1923. Ore production was maintained through an effective utilization of available rail equipment. From time to time as it became necessary to deepen the pit and as stripping ratios increased, various studies were made on alternate material haulage systems. Utilization of diesel locomotives, conveyor belts, and trucks have all been subjects of study, however, conversion from rail haulage utilizing electric locomotives could not be justified. Because of the gradual decline in ore grade, a program was approved in 1963 to raise ore production to 108,000 tons per day. This was designed to return copper production to the 1950 level. Attainment of this production level by expansion of the rail system had definite limitations and built-in inflexibility. Track and trolley wire relocation causes shovel down time in excess of that required for normal maintenance. Instability of the dumps and the resulting additional track maintenance increases greatly as the volume of waste material to be handled daily expands.

Jan 1, 1965

By Randhir S. Sehgal

After some decades of lying low and being treated as a second rate fuel, coal is back in the news. Production is rising. Predictions are for an ever expanding use, and they differ only in their rates of increase. Even the FBI is involved in trying to stop fraudulent sales of non-existent coal lands and leases to the innocent. In short, we have a nearly chaotic boom on our hands. Obviously our energy production base is in the process of undergoing a major shift, and the process will present many problems. However, there is little doubt that the industry has the basic strength and organization to be able to deal with the new issues that will arise as a result of these shifts in production and use of coal. After all, it does produce nearly 800 M tpy now, and coal is the single biggest fuel for generation of electricity. This role of coal is illustrated in the table below, which shows the coal equivalent quantities of various fuels used in the production of electricity.

Jan 1, 1980