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By Guy D. Bruno

Through the remainder of this century, world consumption of fluorine per ton of primary aluminum produced will continue to be substantially reduced. Growth of the primary industry will offset some of the unit consumption, but demand for new fluorine sources will decline sharply. Continued application of dry fume scrubbing systems will be the most significant factor in reducing demand.

Jan 1, 1978

By William Detty

An architect representing the Atlanta office of the Brick Institute of America periodically presents a slide lecture to interested groups entitled "The First 10,000 Years of Brick". The title signifies the fact that brick, man's oldest manufactured building material, has been around for quite some time and will continue to be utilized by architects and builders in the foreseeable future. This is not to say that the brick industry can rest on its laurels and ignore the competition presented by newer more innovative products. The industry will have to be equally inovative and market oriented in order to maintain its market share of the predicted construction boom between now and the year 2000. The implication is made, however, that brick can be produced under rudimentary conditions and that the desire to use the product has been long standing. In addition, history has sham that there has been plentiful clay available to produce the product. This paper is an attempt to assess the climate in which the brick industry will operate during the next 26 years. An analysis of regulatory conditions affecting the manufacture of the product will be followed by an assessment of the materials environment in which the industry will be operating. These factors are then reconciled with a projected demand for the product to determine the ability of the industry to satisfy future demand for brick. From a mineral point of view this paper will address itself generally to the availability of and demand for clay. However, other than a brief overview of the uses of other specific types of clay, it will concentrate on the clays utilized in the production of structural clay products, specifically brick.

Jan 1, 1974

By P. O. Lindahl

The U.S. Bureau of Mines initiated research to improve the safety and efficiency of transporting coal from deep underground mines using a balanced air-lift hydrohoist. A 50-m-high pilot-scale model was constructed and tested to evaluate the feasibility of hydraulically hoisting a coal-water slurry in a U-tube pipeline from the mine level to the surface with the assistance of compressed air. A prototype screw feeder is used to continuously compact and inject 5-cm or less run-of-mine coal into a pressurized 20-cm-diam pipeline. Production rates up to 40 metric tph at an airflow of 1.5 m3/min were achieved with the model, and coal size degradation was relatively minor. Modifications are in progress to achieve 100 tph at an airflow of 2.8 standard m3/min injected into the riser pipe. Pilot-scale results indicate that an air-lift hydrohoist system is a feasible, cost-effective alternative to conventional skip hoisting that can be installed in existing shafts or surface-drilled holes closer to the face area. Air-lift hydrohoisting offers advantages of infinitely adjustable slurry flow rates, reduced pressure at the point of coal injection, and flexible design that can be combined with hydraulic pumping. Proposed design changes are discussed for coal transport, mine layouts, ventilation, fire control, and escapeways using this system.

Jan 1, 1995

By Richard C. Marshall

The heightened concern over the environment which has developed in recent years has caused activities on National Forest lands to come under more intense public scrutiny. This has been especially true for activities oriented toward the production of commodities. Cattle grazing, mining, timber harvesting, and oil and gas leasing and drilling have all been increasingly subject to appeal and litigation. As a result, environmental analyses being conducted by the Forest Service have become more comprehensive, and measures to reduce or eliminate adverse impacts on resources have been given more attention. The costs of such environmental mitigation measures can be significant even when viewed in the context of the millions of dollars a company may spend, for example, to develop a mine. Using the Montanore Project in northwestern Montana as a case study, this paper examines the costs of alleviating some of the detrimental effects which may occur as a result of a mining operation. Although many of the general issues that have been raised about Montanore are common to other mineral projects, the scale of the project, as well as the fact that the ore body is within a wilderness area, the site is in grizzly bear habitat, and the surface waters are considered to be pristine, all combine to make Montanore particularly challenging from an environ- mental standpoint. Much of the information which follows is contained in the most recent version of the Draft Environmental Impact Statement (DEIS) which is scheduled to be published in several weeks. Based on agency and public comments, some of the information presented in the paper will change before the Final Environmental Impact Statement is issued in 1991.

Jan 1, 1991

By Minor S. Jameson

This paper presents considerations in support of a U. S. oil import policy more restrictive than the present Government import program. A lower level of imports and greater long-range stability in the relationship between imports and domestic production are recommended. Reference is made to increasing world-wide surpluses of oil and wide disparities in foreign vs. domestic costs. Resulting economic forces are held responsible for the increase in imports (excluding residual fuel oil) of almost 300 percent and the change in ratio to domestic crude production from 5.4 percent to 13.9 percent during the period 1946-1956 prior to import restrictions. It is pointed out that these imports continued to increase during the years of import restrictions to a ratio of 17.3 percent of domestic production in 1961. Data are presented showing that increasing oil markets outside the United States provide an outlet' for more than 80 percent of total foreign production, with 90 percent of the increase in foreign production going to foreign markets. Attention is called to the fact that, if there had been no increase in United States oil imports during the past five years, foreign production would have increased by 45 percent in contrast to a static level of domestic crude oil production. The need for a less restrictive import policy in the interest of encouraging foreign oil development, therefore, is questioned. Declines since 1956 in the range of 30 percent in domestic exploratory crews, rotary rig activity and wildcat well completions in the United States are cited, together with a decrease of 9 percent in industry employment and increases of 9 to 18 percent in elements of cost. Recognizing that factors other than imports affect the domestic industry, it is concluded that continuing declines in the vigor, capabilities and competitive structure of the domestic industry can be expected unless further import restrictions are imposed. The public interest in assuring adequate domestic supplies is considered in the light of the role of oil and gas as a source of almost three-fourths of U. S. energy requirements and the economic benefits from petroleum production with a value exceeding the combined value of all other minerals in the United States.

Jan 1, 1962

By Dennis N. Poffenroth

One concern of the Mine Safety and Health Administration is the structural integrity of steel wire ropes used on mine personnel hoists and elevators. Failure of such ropes has resulted in loss of life and property. Although thorough and regular visual examinations are performed, hoist ropes may still fail from undetected internal wear, corrosion, and broken wires. To complement visual examinations, nondestructive rope inspection techniques have been developed to determine deterioration and removal criteria. The techniques use electromagnetic and permanent-magnet test instruments designed by a Canadian firm. This paper describes the operating principles, field and laboratory testing of these nondestructive testing instruments, and discusses the feasibility of using this type of testing as a supplement to visual examination and destructive tests.

Jan 1, 1982

By M. F. Werneke

Flotation of the carbonate, oxide and silicate minerals of copper (malachite, azurite, chrysocolla) has been the subject of much research in recent years, but few effective solutions to this problem have been found. With decreasing reserves of sulfide minerals, the economic recovery of these "oxides" appears to be an important source of copper for the future. Xanthates have been known for many years to be malachite collectors (1), but only at very high dosages, or at lower dosages following activation of the mineral by sulfide ion. Dewitt and Batchelder (2, 3) found that chelating agents such as certain oximes were collectors for malachite and azurite, but also required high reagent dosages. Fuerstenau (4) has suggested, for example, that potassium octylhydroxamate may be an effective collector for malachite, On the other hand, Balberyszski (5) has found that oxide minerals may be completely sulfidized at high temperatures with gaseous sulfur or H2S, and then floated with conventional collectors. None of the above approaches appear to offer an economically effective method for the direct flotation of these oxide minerals.

Jan 1, 1977

By Donald R. Williamson

The Cyprus Pima Mining Company's open pit operation was started in 1957 with the normal assumption that the ore reserve estimate was accurate within an acceptable range of values. At that tine reserves were law - volume (+10 million tons) and high grade (+1.5% Cu). Several periods of growth have brought the operation to its present production level of 55,000 tons per day of ore and +125,000 tons of waste. Over the years, a number of attempts to refine and polish the ore reserve figures have been made using a variety of established standard procedures. None of these attempts have produced results which are totally satisfactory, particularly when comparisons are made between ore reserve estimates and short to medium range production figures. Other refinements were tried using adaptations of established methods combined with computer modeling techniques. The resulting mine-model ore blocks were an improvement but they still tended to show too match tonnage of mill feed, often at too low a grade. One attempt at Kriging had only limited success. Statistical studies of operations data revealed relationships which could be used to subdivide ore blocks in much the same way as they are actually mined. Comparisons thus far between these newly developed ore blocks and production data show that the new method of evaluation yields excellent results. A new, better procedure for estimation of ore reserves apparently has been developed for the Cyprus Pima deposits. The specific procedures seem likely to have direct application to other, similar operations. The methods used to develop the procedures could be of value to still other operations.

Jan 1, 1976

By Thomas Sisley, Jozef Zurawski, Richard Switalski

Hilltop Interceptor Contract G is one of the segments of the wastewater control system in the greater Cleveland area. The tunnel is a relief interceptor constructed by the Northeast Ohio Regional Sewer District to minimize combined sewer overflows in the Easterly Service Area. The design study identified the need for a 3.35 m (132 in) diameter, 3.35 km (11,000 ft)in-line storage conveyance tunnel to be constructed at depths of 30 to 70 m (100 to 230 ft).Six structures for access, future flow drop, work shafts and overflow control were required to complete the system. The interceptor reduced the design peak flow from 12.5 m3/s(285 mgd) to 6.1 m3/s (140 mgd) by detaining in line 22,800 m3 (six million gallons) of wastewater.

Jan 1, 1997

By Eugene Guccione

The US mining industry today is fighting for its existence. We are plagued by the shortage of materials, of equipment, of fuels, of capital, of manpower. If we solve those shortages, we are then frustrated in our attempts to open a new mine or, perish the thought, a new smelter. If we manage to make a profit, demagogues will accuse us of stealing from consumers; and, if we do not make a profit and have to shut down, the same demagogues will accuse us of creating unemployment. Meanwhile, in every aspect of our business - from research, exploration and development, to production, marketing and selling - we are hindered in every way by the bipartisan mismanagement and crippling controls of a government bureaucracy gone amok. We are fighting a war on every front. Some of you realize that ours is a war of ideas. In order to win, our industry must make its ideas heard. But to be heard, we must have something to say - which means: we must know our case logically and consistently, all the way down to essential principles. A principle is a primary truth applicable to a great number of instances. A principle is like a road map: it shows you all the possible alternatives for getting from where you are to where you want to go. Although practically everybody recognizes the usefulness of a map and the need to consult it to find the best way' to get from one city to another, most people are not as careful in charting the course of their life, or the course of their industry, or the course of their nation. And so they act blindly, at random, by the whim of the moment, and get nowhere fast.

Jan 1, 1975

By N. Agron-Olshina

The application of the QEM*SEM image acquisition and analysis system to the measurement of the mineral matter in coal and the materials in fly ash is described. A new sample mounting technique was developed using iodinated epoxy to provide a backscattered electron contrast between the coal, the mounting medium and the mineral matter. Several comprehensive and detailed species identification programs for silicate minerals and materials were developed to analyse the 1000 count x-ray spectra used for the measurements. Case studies are presented to demonstrate the capabilities of the new technique to distinguish different coals and fly ashes by their mineral and material composition rather than by conventional chemical analysis. Applications of the new technique are aimed at demonstrating that composition and size distributions obtained from OEM*SEM measurements can be used: 1. to characterize coal with respect to combustion problems in power stations, 2. to characterize coal for fine coal cleaning, 3. to characterize fly ashes in relation to problems such as erosion in combustion systems and the ease of precipitability in dust collection facilities, 4. to refine the classification systems used in marketing coal for pulverized fuel firing and fly ashes as a component of cement and building materials.

Jan 1, 1992

By Xiaobo Zhang, Panshi Xie, Xiaobo Wu, Ding Lang, Jiandong Yu, Yongping Wu, Kun Feng

In a fully mechanized top coal caving mining process, the mechanical properties of the top coal deteriorate constantly, and the stability of the support is determined by the boundary position of the top coal entering the limit equilibrium state. Top coal flaking occurs more easily along the advancing direction owing to an increase in the distance of the boundary from the wall. Moreover, the strength of the coal seam is an important factor that determines the boundary position. The equation of the top coal limit equilibrium zone boundary, used in fully mechanized top coal caving mining, was determined based on the limit equilibrium theory, continuum damage mechanics, and the Hoek–Brown rock empirical strength criterion. Using the RFPA3D and UDEC numerical analysis methods, the effect of top coal strength on the mechanical behavior during the mining process was determined; and the space–time relationship between the top coal deformation failure, damage evolution, and boundary of the limit equilibrium zone was established. The results revealed that when the coal mass entered the limit equilibrium zone, accelerated crack development, accelerated damage, and axial unloading occurred. Moreover, an increase in the coal seam strength caused the boundary of the top coal limit equilibrium zone to be closer to the wall. By comparing the numerical results with the theoretical results, the overall trend was found to be consistent, allowing the verification of the rationality and reliability of the determination equation of the boundary position of the limit equilibrium zone.

Sep 21, 2021

By Javad Sattarvand, Frimpong Kwaku Asare

The safe evacuation of miners during an emergency in the shortest amount of time is one of the most essential features of a mining operation. Despite advancements in mine evacuation research, the usage of mine vehicles during evacuation has not been considered. The majority of recent studies have been done on miners’ evacuation on foot. Mathematical formulations including Minimum Cost Network Flow (MCNF) models, Dijkstra's algorithm, Floyd-Warshall algorithm, and Ant Colony Optimization models have been used to solve mine evacuation problems. These models, which concentrate on determining the shortest escape routes during the evacuation, have been found to be computationally expensive and may not offer the best solutions in some cases. The goal of this paper is to incorporate light vehicles in the evacuation process using a mixed-integer programming approach. The methodology aims to minimize the total time required to evacuate the mine, ensuring minimal exposure of the miners to the adverse conditions that triggered the evacuation.

Jun 25, 2023

By Peter P. Harvey

The Nonel Primadet is a non-electric blasting initiation device. The system incorporates the safety advantages of a cap and fuse system with the precision blasting afforded by electrical blasting caps. Each unit is made up of a delay blasting cap factory-crimped to a Nonel® shock tube lead line. The delay elements in the blasting caps are manufactured in both millisecond and long period series. There are 16 periods available in both series - period 0 through period 15. The units are manufactured in 12', 16', and 20' lead lengths. The hollow shock tube is made of surlyn plastic and it is coated on the inside with a reactive material. The powder train has a density of only 1/10 grain per linear foot of tube. A typical blast round is timed precisely the same way it would be with electrical caps. After the round has been timed and loaded, the tube leads are gathered in convenient bunches and tied into a detonating cord trunkline. The Nonel® tube bunches are initiated by the output of an 18 grain per foot detonating cord trunkline. Once initiated, the Nonel® shock tube will reliably propagate at 1800 meters per second. The energy from this shock front initiates the delay elements in each delay cap. The shock tube is inert to electrical energies, including; stray current from AC/DC power sources, as well as, electrostatic discharges. The tube is also inert to initiation by impact. The system has proven to be particularly advantageous in both tunnel and shaft blasting applications. The major advantages in using the Nonel® system in this type of work are: 1) faster and easier tie-in techniques through the use of bunch-blasting. 2) electrical power can be left on during loading and tying-in. a. electrical lights can be turned on at the working face - better lighting facilitates loading and tying-in. b. electrical pumps can continue to function throughout loading and priming procedures (this is particularly advantageous in shaft work with water problems). 3) down-time due to approaching electrical storms is minimized. 4) increased overall efficiency in the blasting cycle: a. it is easier to train a man in the proper use of the system. b. fewer missed holes per round. c. less time required for tie-in. 5) safety-advantage--The system is not susceptible to involuntary initiation from extraneous electrical energies.

Jan 1, 1979

By C. Patrick

Annually, the U.S. coal industry generates and must dispose of over 200 million tons of coal refuse, expanding a major environmental problem. The purpose of this research was to investigate the feasibility of utilizing coal refuse as an aggregate in concrete. This paper reports on findings of the initial phases of a project to determine the viability of replacing traditional concrete blocks, used for under-ground ventilation stoppings, with refuse blocks. Refuse was collected from three active preparation plants in Eastern Kentucky and used as the primary aggregate for concrete cylinders. The refuse fell within ranges normally observed for size consist, moisture, and ash. Stress-strain analyses yielded compressive strengths of the refuse cylinders from 59% to 77% of the control group strengths. Low variability within groups while significant differences between groups were found. On-going determination of effects of weathering on the refuse cylinders is being conducted and will be completed in early 1995. The research results are favorable for the future direction of the overall project objectives.

Jan 1, 1995

By Ken Takahashi, Yuuich Umeki, Masahiko Arakawa, Dr. Tominaga. Yuusaku

Macroscopic characteristics of a complicated mine ventilation is remarked to build an expert system for mine safety in the Taiheiyo coal mine, Hokkaido, Japan. To gain the characteristics a large number of simulation were performed with varying aerodynamic resistance of the branches with regulator in mine ventilation network. The principal results of the study are as follows, (1) Pressure loss diagram for ventilation network with main and auxiliary fans enables capability of air circulation in the network. (2) H-Q (pressure-quantity) diagram gives capacity of air quantity In a network with main and auxiliary fans. (3) When airflow rate, [] through branch qi is changed by opening/closing regulator set in the branch, air flow rate, [], through branch p can be represented by the empirical formula. [ ] where Api and Qp,o are the constant coefficients. (4) Macroscopic characteristics mentioned above are available to make rules in an expert system for escaping route at emergency.

Jan 1, 1989

By Nina I. Fedunec, Olga E. Fomicheva

Results of researches on creation of the intelligent adviser system for mining dispatcher are represented. A method of the analysis of subject domain is considered and results as the generalized expert questionnaire and diagrams are represented. The system-adviser REALTREE, functioning in real time, is represented, results of an estimation of a system effectiveness during decision making by the dispatcher are submitted.

Jan 1, 1996

By Arash Habibi, Anna Cable, David Loring, Aleksandar D. Bugarski, Logan Ingalls, Calvin Rutter

The results of diesel particulate matter (DPM) monitoring were used by the underground mining industry to mitigate adverse effects of exposure to DPM. NIOSH Method 5040, currently used for ambient and personal exposure monitoring, does not provide needed real-time information. The objective of this study is to develop a methodology for continuous monitoring of DPM concentrations in an underground environment, founded on the application of the Dekati electrical particle sensor (DePS). The DePS, which measures concentrations of submicron aerosol in real time using a diffusion-charging sensor, was evaluated by comparing the results of the concurrent measurements with reference methods at several locations downstream of the diesel-powered equipment. The DePS results were found to correlate well to those obtained by reference methods. However, it was found that dependence of the response on the physical and chemical properties of aerosols necessitates sitespecific correlation factors for the targeted matrices. The site-specific factors for number and mass of diesel aerosols were derived using the results of concurrent measurements with TSI NanoScan, FLIR Airtec, and carbon analyses performed on the concurrently collected filter samples. The results showed that methodology based on compensated DePS measurements would be suitable for continuous monitoring of DPM in underground mining operations.

Dec 1, 2022

By James A. Curry

Table I identifies the maximum cost of the individual provisions with spoil disposal in Appalachia leading at $3.98 per ton, This was followed by deep mine subsidence control and monitoring at $1.66 per ton. At the request of the U.S. Department of Energy, the Bowser-Morner Testing Laboratories of Dayton, Ohio, evaluated Consol's cost estimates for 14 of the 21 regulatory provisions the company studied. It is interesting to note that Bowser-Morner concluded that Consol's estimates of costs were very conservative and that the actual costs will be substantially higher than what the company reported. In 1978 a joint committee of the National Coal Association and the American Mining Congress made estimates of cost impacts under 11 OSM permanent rules (see Table II). Six rules applied to mid-western strip mining were projected to cost $6.52 to $17.17 per ton. Five rules applied to mid-western strip mines showed costs ranging from $.91 to $6.11 per ton. Three rules applied to deep mines (regardless of region) were seen raising costs from $ .57 to $2.67 per ton. The joint committee reported trouble developing overall figures because member firms used widely different assumptions in calculating their costs. That same statement could no doubt be made when comparing most cost data available today.

Jan 1, 1980

By Dirk van Zyl

Natural materials can be used successfully in the construction of heap leach pads. The use of these materials usually result in the least expensive approach for such facilities. Sufficient geotechnical experience has been gained in the design and construction of clay heap leach pads so that they can be used with confidence. A number of operators presently use clay pads in their heap leach facilities; these include Alligator Ridge, Ely, Nevada (gold), and Union Carbide, Gas Hills, Wyoming (uranium). This paper describes the construction and field investigation of a clay pad for the heap leaching of agglomerated precious tailings. The project is located in the Mojave Desert, Southern California. The design had to satisfy operational requirements as well as regulatory requirements. The California Water Quality Control Board (WQCB) was one of the agencies which had to issue a permit for the project. Their biggest concern was the discharge or escape of cyanide into the environment. Rather stringent requirements were therefore placed on the pad design criteria, especially in terms of permeability.

Jan 1, 1983