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By Truman Harrington

During the last decade, diesel engine manufacturers focused their research efforts on higher efficiencies and horsepower-to-weight ratios. The result was horsepower increases of between 20% and 30%. At the same time, coolant volume decreased by about the same amount. This has made coolant maintenance more important to ensure a long life for the engine and its cooling system. Due to dilution and additive depletion, supplemental conditioners are usually added to the coolant system during an oil change. Dilution occurs when coolant leaks from the system, and water or non-conditioned antifreeze is added. Depletion is a more complicated process that involves oxidation, neutralization, precipitation and metal surface reactions.

Jan 1, 1991

By Dale C. Matthews

Pressure oxidation of refractory gold ores is becoming more popular in what has become an environmentally sensitive society. This article discusses some specific process problems and solutions involved with starting up and operating an autoclave circuit. The Getchell gold deposit is located about 72 km (45 miles) northeast of Winnemucca, NV. The deposit was discovered in 1934 and first production came about in 1938. The oxide portion of the ore body was mined and milled from about 1936 through 1950. Refractory arsenic-bearing sulfide ores had long been known to exist in the Getchell deposit. These ores had been mined concurrently with the oxides since 1938.

Jan 1, 1991

By Chien-Tsun “C. T. ” Chu, Drupad B. Desai, Ron E. Redd

The 12,710-m (41,720-ft) Riverside Badlands Tunnel is located between the most active faults—San Andreas and San Jacinto—in Southern California. To accomplish the impervious final lining design and to accommodate the effects of earthquake ground motions, a new approach was developed and is prescribed in this paper. Two final lining options, welded steel pipe and prestressed concrete cylinder pipe, are considered for the tunnel, which will be excavated under groundwater and ground conditions from soft rock to hardrock at depths exceeding 244 m (800 ft). The buckling strength, serviceability, and structural integrity under seismic effects and other loads were considered in the design.

Jan 1, 1997

By J. P. Stone

The Mining Regulatory Affairs review arrived in time for the May issue. The Managing Editor inadvertently buried it in one of his paper piles. Regulatory developments at the federal level involving the minerals industry solid waste disposal under the Resources Conservation and Recovery Act (RCRA) remained at the forefront of concern. The Environmental Protection Agency (EPA) received public comments on two major documents. One was a strawman draft rule covering wastes from mining and beneficiation. The other was a report to congress covering selected mineral processing wastes. The regulation of minerals industry waste management is moving forward on parallel paths. Mining and beneficiation waste is somewhat further advanced.

Jan 1, 1991

By S. T. Krukowski

Traditionally the lime industry is governed by market, location, and transportation. These factors also may act as obstacles to global market access. Lime manufacture responds to market opportunities by first focusing on location. Lime markets are diverse and widespread, and ubiquitous occurrences of limestone make development of a widespread industry possible. Lime’s low to moderate unit value restricts transporting it long distances. Other factors (including lime reactivity, dedicated container use and other liabilities) limit shipping lime far. In the past many small to medium size companies made lime for local use. Today the global aspect of the industry is ownership by few large companies producing lime for local consumption.

Jan 1, 2003

By J. E. Warm

Florida’s ancient beach ridge sand deposits, mined for construction aggregate, are highly variable. Rinker Materials utilizes a small reverse-circulation drill rig to prospect and profile unconsolidated fine aggregate deposits more effectively and inexpensively than other drilling methods. Sample data is stored in a spreadsheet that calculates yield and volume. Rinker also uses a Trimble ProXR backpack GPS to locate boreholes in the field, track mine progression on a monthly basis, and to map restrictive features such as wetlands. Autodesk Land software is used to create detailed deposit maps and mine plans. Rinker believes that these practices have led to improved awareness of deposit characteristics and deposit utilization.

Jan 1, 2004

By K. Valta

This paper presents an approach for developing a Sustainable Development Indicators (SDIs) framework tailored to the Greek Industrial Minerals sector, due to its importance for the national economy. To achieve this goal, an overview of the Greek mining and minerals, and especially the Industrial Minerals sector, from a technological and a financial perspective, is presented. In addition, a brief description of the global initiatives to this direction is given. The proposed indicators are based on those presented in 2006 by the Greek Mining Enterprises Association (GMEA) adjusted for the sector of industrial minerals by taking into account economic, environmental and social issues, known as the Triple Bottom Line (TBL) approach.

Jan 1, 2007

By J. H. LaVerne Palmer, W. (Bill) C. Cox, Lorant B. Geller

An erector transporter (ET) has been designed and built to lift, carry and erect heavy machinery components, in particular the components of a 7.6 m diameter tunnel boring machine (TBM), within the access tunnels of a submarine coal mine in Eastern Canada. The ET is capable of manoeuvring within a 7.6 m tunnel while precisely positioning components as large as 6 m in diameter and weighing up to 27 tonnes each. The unit can negotiate 20% grades while carrying loads of 30 tonnes. The major design features, verification tests and performance trial results are presented. The versatility of the ET is such that many other applications are possible.

Jan 1, 1985

By A. Geertsema

Introduction Gasification of coal has been practiced for many decades for the production of gas, fuels, chemicals and power. However it has only more recently started to get significant attention in the USA. In this review of the basics the features of gasification as compared with combustion is covered and the potential of increasing the conversion of coal via gasification is indicated. After dealing with the fundamentals of gasification a review of gasification technologies will be presented with an indication of the widespread international and more limited US use of this technology. In conclusion the attention will be directed at the future prospects of gasification.

Jan 1, 2006

By Thomas F. Pugsley, Wilf J. Davies, James Gallagher

Falconbridge Limited is developing a major nickel mine at Craig which lies between 600 m, 915 m and 1500 m below surface and is accessed on the 600 m and 1250 m levels of Onaping Mine. To supply adequate ventilation for mine development and initial ore production, two raises, 1200 m long are to be driven in norite and granitic gneiss. Falconbridge has purchased a Robbins 97RL Raise Drill and a string of 330 mm drill pipe to ream these raises in 600 m legs at diameter. The paper describes the introduction of deep hole, large diameter raise boring technology into Falconbridge operations involving contractors and specialists in the technology.

Jan 1, 1989

By Lane White

In conjunction with its 1993 Annual Meeting, held Feb. 15-18 in Reno, NV, SME sponsored a symposium, "Conveyor Belt Engineering for the Coal and Mineral Mining Industries." Eighteen papers were presented, grouped into four sessions: Low Tension Drives, High Tension Drives. Novel Techniques and Specifications. Three of the papers have been republished in this issue of MINING ENGINEERING. Brief summaries of the other 15 papers are presented here. (The 193-page symposium Proceedings, edited by Mike Evans of Consol, includes all of these 18 papers and is available from SME. For the convience of interested readers, an order form is included at the end of this Proceedings summary.)

Jan 1, 1993

By Brij M. Moudgil, Ivan U. Vakarelski, Yakov I. Rabinovich

Polymer and surfactant dispersant are widely used to disperse filler particles within a medium. Sur- faces active dispersants form self-assemble structures at the solid-liquid interface. The mechanical properties of the surfactant structures have been determined to strongly influence the dispersion behavior. In this study the atomic force microscope (AFM) is used to determine the elastic modulus and yield strength of a steric dispersant layer adsorbed to a rigid non-deformable surface. To interpret these values a model for elastic body contact based on a modified Hertz theory is applied. The results from this method may aid in the design of application-based dispersant systems.

Jan 1, 2003

By G. J. Lindenburg, T. L. Wilson

The Velvet uranium mine is located in the Big Indian district of the Colorado Plateau. The uranium ore body lies within the lower Triassic Chinle Formation, and the ore is associated with west-south-westerly trending fluvial sand systems. Exploration and mining are directed by longhole drilling and radiometric sampling. Results of the gamma probing, face scanning, and geologic mapping guide mining decisions and planning. Three people are directly involved with the geologic procedures: two geologists and a mine supervisor. The two geologists map, do rib scans, and direct longhole drilling. The third man involved, the mine supervisor, has last minute directive action based on shot hole probe data.

Jan 1, 1992

By Allyn J. Steward

The 14,350 m (47,000 ft) Mount MacDonald Tunnel is nearing completion. North America's longest railroad tunnel is being advanced from each end by two contractors. This presentation outlines techniques employed by the Manning Kumagai Joint Venture, working from the west portal. Rapid construction was achieved by simultaneous installation of cast in place arch-wall lining and drill and blast excavation. Extensive planning, judicious choice of equipment and efficient crews combined to shorten the original schedule. Manning Kumagai was also awarded the tunnel mid-section as a separate contract. This includes construction of an underground chamber and structure for a unique permanent ventilation system.

Jan 1, 1987

By Antonio Peralta, Guillermo Dante Ramírez-Rodríguez

Mining is generally considered a large-scale hightech industry. However, it has estimated that about 12 million people, about 30% of the world’s total mining workforce, relied on small-scale mining for their livelihoods. During the years, the large-scale mining industry has developed best practice environmental procedures, which have been applied in diverse settings through the world. In contrast, small-scale mining is better known for its high environmental impact and the lack of safe and healthy working conditions. This paper will discuss the environmental control strategies used by the large-scale mining industry, and its applicability to small-scale mining in developing countries.

Jan 1, 2005

By J. Engel

The talc deposit in Gemerská Poloma lies 350 to 400 m under the surface; the whole deposit is located at the highest-level drinking-water-source protection zone, therefore, opening in this mining area (a well, a ramp) requires higher investment, operational and water protection costs. The adit, outside the mining area, with a length of 4200 m, rising with a gradient of 3? and a diameter of 10.3 m2, allows free passage/runoff of mining-water through the adit, and guarantees low costs for transporting produced material and equipment. This solution is in total less demanding from both investment and operational point of view.

Jan 1, 2007

By K. A. Natarajan, P. Somasundaran, Namita Deo

Biological processes have recently become more attractive in hydrometallurgy and mineral processing due to their lower operating costs, potential for processing low-quality ores and flexibility. Adhesion of microbes and their metabolic products can modify the particles to render them hydrophobic or hydrophilic. Such modifications of the surface properties are used in flotation and flocculation of minerals. Microbes are also able to dissolve different precious metals from their ores. In this paper, the role of microbes and their metabolic products as surface modifying reagents in extraction processes is discussed. In addition, the ability of certain microbes to adsorb toxic metal ions or to degrade toxic chemicals discharged by industries is examined.

Jan 1, 2000

By D. W. Fuerstenau, P. C. Kapur

A model equation is presented for breakage of single particles as a function of the impact energy. The model takes explicit cognizance of the distribution of feed particles in their resistance to breakage as well as of the weakening of particles under repeated impacts. With the proposed formulation, it is possible to simulate the size spectra of progeny particles, interrelate quantitatively the so-called ‘t’ family of curves, derive an energy-size reduction relationship, compute the primary, energy-free breakage distribution function, and predict the optimum level of impact energy for a given size reduction task. Published data on single-particle impact grinding are in agreement with the model.

Jan 1, 1995

By Z. Zhang, R. G. Reddy

The viscosities of industrial lead slags of varying compositions were measured as a junction of temperature using a Brookfield viscometer. Based on the experimental data obtained from this study and based on other investigations reported in the literature, an expression was developed to correlate the viscosities of industrial lead silicate slags as a function of composition and temperature. The effect of each individual slag component on the variation of the slag viscosity is identified. The composition dependency of lead silicate slag viscosity is discussed. The calculated results using this viscosity expression are in good agreement with the measured data. Key words: Viscosity, Lead silicate slags

Jan 1, 2003

By K. V. S. Sastry

Pelletization, sintering, and pressure compaction are the most common methods used to agglomerate ore concentrates. Over the last 20 years agglomeration has grown enormously in popularity and has become a standard unit operation in the nonferrous, cement, fertilizer, and ceramic industries. However, it is in the processing of iron ores and the preparation of blast furnace feed that agglomeration is used most and its application has grown fastest (Ball, et al., 1973; and Sastry, 1977). This chapter deals with an account of the current practices and future trends in the application of computers relative to an overview of the process design and engineering considerations of the unit operation of agglomeration.

Jan 1, 1979