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By David Morrison

"The history of the mining industry is littered with in-pit crushing and conveying (IPCC), which should not be confused with the International Protocol for Carbon Capture, projects that failed. The failure is not the technical one of “did it achieve the desired tonnage rate for a longish test period” but, rather, the far more important one of “did it provide return on the investment in the manner that was promised?” While quite a few can claim the former, very few system installations can claim the latter.The reasons for the many failures are numerous, but they are all characterized by a combination of an element of engineering optimism in any, or all of the production rates, the productivity, or the operating and maintenance costs and in predicting the continuity of operating conditions. In these days of big data, propagating such a situation is rapidly becoming unforgivable.In this article, the three most common scenarios put to the corporate board for approval, and the logic as to why they were selected, are examined (with the irony included intentionally).• Fully mobile crusher, fed by a shovel and conveyed out of the pit to a waste dump / process plant.• Semimobile crusher (much more expensive than a fixed crushing station but which apparently allows trucks to short haul inside the pit and improve productivity), which moves when the face moves.• Relocatable crusher (more expensive than a fixed crushing station but which gets relocated at great expense after all the fixed infrastructure impeding relocation is demolished) fed by trucks that don’t leave the pit mostly.This paper will also consider the truth about their operational performance and associate costs."

Dec 1, 2016

By J. C. Heter

The P.W. Gillibrand Company has been processing and stockpiling a suite of heavy minerals at its Soledad Canyon Mine as co-products with construction aggregates since 1984. The heavy minerals are composed of ilmenite, magnetitie, apatite and zircon. The source of the heavy minerals is the Precambrian San Gabriel Anorthosite Complex of the western San Gabriel Mountains. The valuable minerals are readily amenable to standard ore dressing techniques, such as, gravity, magnetic, flotation and electrostatic separation with good recovery and product quality. More than 20,000 short tons of coarse ilmenite were sold in 1990 to the export market for titanium pigment production.

Jan 1, 1992

By W. M. Middleton

The exploiting of geothermal steam is a new endeavor in this country and is for that matter a very new science in the world. With the majority of steam wells in the world having been drilled during the last twelve years relatively little experience and knowledge has been gained that can guide us as compared to the techniques the oil and gas producers have developed for their use. We few technical personnel associated with the field find it a continuous challenge to understand and explain what effects or causes the various unusual phenomenon experienced. We have had unending discussions attempting to formulate pet theories which we can use as guides. We know, so the geologists tell us, that the source of the heat is from the hot magmatic core of the earth. Theory has it that the magma is cooling off and that hot gases are given off as this magma cools and shrinks. In volcanic' areas along fault lines where the magma reaches closer to the surface than in other areas, there is a higher concentration of gas evolution; consequently, geyser or geothermal areas are developed. As these hot gases rise toward the surface they encounter various minerals, including overlying bodies of water. It is into these underground lakes that our wells are penetrating. As the heat enters these lakes it spreads out by conduction, convection and water migration. We can strike this hot water over quite large areas in many of the geothermal fields. At present there is one anomaly to this in the United States as there is in Italy where our wells do not penetrate a hot water lake. This is at The Big Geysers in California. Here superheated steam is produced with a heat content, so high that it could not have been boiled off of a fresh water pool. This puzzled us until last year when a well was completed into a large body of brine in the Imperial Valley. This brine exists at close to 500°F and at a hydrostatic pressure sufficient to preclude any boiling. It is now believed by some of us that a similar pool of brine must exist below The Big Geysers area, from which the steam is emanating. If there is such a brine pool, it offers a plausible explanation of the high-heat content, for brine boils at a higher temperature than fresh water. I am now beginning to think that a similar brine pool may exist under all the geothermal basins for if it is under two of them, it is highly probable that it is under the others. The partial understanding of what we are drilling toward, and formulating a theory to explain its behavior helps guide us in our steam well drilling.

Jan 1, 1963

By R. E. Turner

Hamersley Iron Pty. Limited, one of the world's largest iron ore producers, operates a 3.0 million tonne per year pelletizing facility at Dampier in Western Australia. The plant produces pellets for the export market using a blend of natural hematite fines from the Company's two mines at Tom Price and Paraburdoo. Processing includes fluidised-bed drying of the ore feed, open circuit dry grinding, disc balling and pellet induration in a travelling grate furnace of Dravo-Lurgi design.

Jan 1, 1980

By M. E. Smith

Chile is the world's largest copper producer and as such sets the standard of practice in copper SX/EW design. The authors summarize the liner systems used at many of Chile's major copper producers both operating and planned. The evolution in the state of the art is also discussed, considering both economic factors and Chile's burgeoning environmentalism.

Jan 1, 1994

By James E. Jones

The coal mining industry is being called upon to vastly increase production in the coming years. Many mining operations will have to prepare an environmental impact report of some kind and all will have to comply with various types of environ- mental regulations. Therefore there is a great need within the industry for access to environmental data, information, and literature. This paper discusses the informational resources available, the current lack of access to these resources, and the Environmental Data, Information and Literature (EDIL) Bank of the Kentucky Institute for Mining and Minerals Research. The bank's major emphasis concerns the environmental, social and economic aspects of producing clean solid, liquid, and gaseous fuels from coal. The data bank promotes information interchange between other related governmental and private projects and the energy development community.

Jan 1, 1976

By T. B. Szwilski

ISO 14000 series are voluntary international standards that address environmental management system standards, environmental auditing, environmental labeling, environmental performance evaluation, and life-cycle assessment. An environmental management system (EMS) is a facet of an organization's structure that addresses the immediate and long-term impact of a company's products, services, and processes on the environment. Many companies in the United States are taking a cautious wait-and-see approach before embracing ISO 14000. A few mining companies are reviewing the standards and using them as guidelines. The paper outlines the status, possible benefits to the mining industry, and options available to a company wanting to become involved in the ISO 14000 standards.

Jan 1, 1997

By M. J. Gula

In the solvent extraction -electrowinning recovery of copper from oxide or sulfide ores there is a continuous transfer of iron and other impurities from the primary leach solution to the copper electrowinning electrolyte via chemical transfer or mechanical entrainment. Iron is the principal impurity that has to be controlled in the electrolyte by a "bleeding" of the electrowinning solution. This bleeding transfers copper and sulfuric acid back to the primary leach circuit along with the iron. Copper is recovered via the solvent extraction process and generally the sulfuric acid is used as a reagent in leaching. Unfortunately, cobalt, which is added to the electrowinning solution to modify the anodic process, is irreversibly lost through the bleeding operation. This cobalt loss represents a significant operating cost to SX-EW copper producers. DiphonixTM ion exchange resin contains diphosphonic acid and sulfonic acid functional groups on a polystyrene-divinyl benzene matrix. This resin has been found to strongly and selectively extract ferric ion from copper sulfate -sulfuric acid solutions containing cobalt. Thus, an ion exchange process using DiphonixTM resin for the control of iron has been developed to replace the conventional bleed stream process. The new process minimizes the loss of cobalt from the electrowinning circuit and strips the iron into a sulfate based solution suitable for leach solution makeup. In addition, this process can effect a lowering of the total iron concentration in the electrolyte circuit with an associated increase in current efficiency. In this paper, data on the loading and elution of iron are presented. Laboratory and pilot scale data will be discussed along with information on process design and comparative economics.

Jan 1, 1996

Smart defense: that?s what the industry needs to play for the next four years, according to panelists at the 118th Annual Meeting of the Northwest Mining Association (NWMA), which met December 2-7 in Spokane, WA. The conference was well attended, with approximately 2,200 attendees, 244 booths in the two packed exhibition halls, and a rich offering of short courses, field trips, social events and technical sessions. Speakers at the packed legislative session articulated many of the frustrations felt by members of the mining community after the U.S. elections in November, and offered words of advice. Matthew Ellsworth, the new Government Affairs hire at NWMA, stated it best: ?Elections are like Christmas: you find out who?s naughty and nice ? and it?s always going to come again.?

Jan 1, 2013

By D. Kelley

Due to pricing volatility and lack of availability of metals, the use of non-metallic materials of construction in metal extraction and refining processes has increased significantly in recent years Even though costs and availability of metals has improved recently, these factors are not expected to continue into the future as metal supplies once again fall short of global demand. One of the most common non-metallic materials of construction used in metal extraction and refining processes today is Fiberglass- Reinforced Plastic (FRP). These processes often require materials of construction that can resist acids and high concentrations of acid chloride salts. As shown in Table 1, FRP based on epoxy vinyl ester resin has the same chemical resistance to acid and better resistance to acid chloride salts than alloy C-276 and is superior to 2205 stainless steel in both cases.

Jan 1, 2010

By B. G. White

Traditional interpretations of vein ore deposits in the Coeur d' Alene Mining District, such as the view that these deposits formed in a transcurrent tectonic regime during the Precambrian, are being supplanted by the view that the deposits (1) formed in low-grade metamorphic shear zones similar to those that host an important type of gold deposit, (2) display features, such as wall rock carbonate zoning and vein zoning, that are common to ore deposits elsewhere, and (3) are probably Mesozoic and possibly related to emplacement of the Idaho batholith. In recent years, new interpretations have led to major ore discoveries that are likely to extend the life of the district for decades.

Jan 1, 1998

By Edward Holloway

The basis for the selection of the ultimate pit for an open pit mining operation is generally opaque. Some form of value-based analysis will generally guide the final decision; however, the value will often gradually plateau whilst the ultimate pit size continues to increase. There is no established framework to guide specialists in the selection of the ultimate pit, with such decisions regularly made on a somewhat arbitrary basis. The key component that is missing from the analyses typically used to select the size of the ultimate pit is risk. Once risk is quantified within the analysis framework, the decision-making range is significantly reduced, and the process for selecting the ultimate pit becomes more consistent, replicable, and defensible. This paper provides an approach to including risk in the process used to select the ultimate pit.

Feb 21, 2024

By J. S. Wozek

In metallurgical applications, coal fulfills dual roles as a chemical feed stock and as a fuel source. These applications range from cokemaking, ironrnaking (including pulverized coal injection), foundry, basic oxygen furnace / electric arc furnace coal additions, direct ironrnaking, Corex, and the futuristic direct steelmaking. In all steelmaking related processes, chemical reactions are simultaneously temperature and chemical dependent. Therefore, coals used in these processes must consistently comply with specific quality parameters in order to promote efficient operations. This paper limits discussion of Metallurgical Coal Quality to cokemaking and ironmaking applications. Its purpose is to present the customer's perspective on the control of critical coal and coke properties.

Jan 1, 1994

By R. L. Grayson

The health and safety of employees, efficiency of the operating system and production are paramount goals in underground coal mining. The section foreman assumes responsibility for making his part of the total system function to meet these goals. However, section foremen often have not been prepared to assume the full range of their responsibilities upon becoming a supervisor. This discussion addresses the full range of section foreman responsibilities and concomitant authority. Management principles that must be mastered by him are presented, and performance expectations as well as criteria for their evaluation are examined. The benefits realized from effective foreman training are discussed.

Jan 1, 1985

By Edgar T. Gregory

A quiet revolution has taken place in the conveyor belt industry, Man-made materials, improved production facilities, better splicing techniques and emphasis on repair and maintenance have all contributed substantially to lowering material handling costs for the mining industry, It wasn't too many years ago that the rubber industry had only cotton for a belt carcass and tree grown rubber for the protective cover. Then came the development of monofilament rayon. This material had desirable elongation and elastic properties and was the first synthetic fiber to be used in place of cotton. But wet strength and other limitations restricted its use, and the conveyor belt industry turned to nylon. Initially, nylon was considered suitable only for the cross threads or filler threads of a belt carcass. Then technical advancements in heat setting and fabric weave created a major change in belt construction. As a result of these advances the industry was able to take advantage of the full tension strength of nylon cord. Another breakthrough in the use of synthetics was the tremendous increase in adhesion resulting from a chemical bond, rather than the limited physical bond available with cotton. But the advantages of nylon had a more Car-reaching effect, We were able to design a two-ply nylon belt that did the work of a four- or five-ply cotton or rayon belt. A six-ply nylon belt now replaces a twelve-ply cotton elevator belt. Arid nylon resists moisture, acid and mildew, It also has excellent resistance to impact and can be produced with controlled elongation and elastic properties that work to great advantage in reduced-ply belt constructions.

Jan 1, 1971

By Christopher Mark

Sixty years ago, underground coal mining was the most hazardous job in the United States. Roof falls were a big part of the problem. They killed about 100 miners every year, more than all other causes put together. Fast forward half a century to 2016, which is the first year ever with zero roof fall fatalities. Just three miners were killed by roof falls during the following 6 years. How was this historic goal achieved? This paper starts with a modern analysis of the causes of the roof fall fatalities in 1968. Then it follows the reductions over time by category, using snapshots of the fatalities occurring in subsequent decades. Along the way, it evaluates the influence of the regulatory environment, changing mining methods, and better ground control technology. The paper shows that in 1968, more than half of roof fall fatalities at large mines were attributable to an inadequate safety culture. The immediate effect of the 1969 Coal Mine Health and Safety Act was to reduce the riskiest activities, like needlessly going under unsupported roof. Other hazards, like large roof falls, required technological developments before they were brought under control. Roof control plans, which the U.S. Bureau of Mines had been advocating since the 1920s, played a significant role throughout the process.

Jul 1, 2023

By D. G. Abbott

This paper will describe the development, testing, performance evaluation, and in particular, the utilization for a mining application of revolutionary new mini-disc cutters for use in micro-tunneling and small-and medium-diameter tunneling or mining. It will begin by describing the engineering, testing, and development of rock cutting technology in conjunction with the Rock Boring Laboratories of the Colorado School of Mines. During initial tests, the five-inch cutters were able to penetrate limestone and welded tuff with compressive strengths of 9,000 psi to 24,000 psi. High excavation rates at low thrust and power were achieved with considerably less cutter wear than all previously available conventional discs. Eventually, the discs-with their modified carbide-insert cutting rings, high-load capacity bearings and cantilevered mountings-were able to facilitate the rapid and cost-effective installation of micro-and small-diameter pipes and tunnels in large cobbles and even solid rock, with compressive strengths exceeding 30,000 psi. This paper will also discuss the further development of the machine's cutter head and discs to full-scale site use on a range of tunnel machine sizes and soil conditions, including rock, boulders, and soft ground. Potential mining applications include the installation of tunnels to pro-vide ventilation, emergency escape routes, water drainage, compressed air, electricity, and sand-fill.

Jan 1, 1996

By Michael N. Greeley

The movement to reclaim abandoned mine sites has gained momentum as federal, state, and private organizations have increased their commitment and resources to tackle mutual, and often controversial, problems of health and safety. Numerous interorganizational agreements have been implemented to promote cooperation in the characterization of mine site hazards, development of mutually acceptable plans of remediation, and sharing of actual cleanup requirements. Working through these partnerships, the federal land management agencies have begun to focus on abandoned mine reclamation in selected, priority watersheds and other drainage basins. Although there are major difficulties to overcome, significant progress continues to be made.

Jan 1, 1999

By M. R. Yenchek

Faulty insulators on mine trolley/track haulageways may allow the flow of leakage currents into the mine roof and ultimately result in combustion of the local roof material. The National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL), has devised a passive means to detect overheating insulators on direct current systems. The detector consists of a spring-loaded cartridge that ejects a reflective streamer of white Teflon tape when subjected to elevated temperatures. The cartridge assembly can be easily installed over the outer metallic shell of an existing trolley line insulator. If an insulator overheats due to ground leakage currents, the visible streamer alerts mine personnel traveling on the haulageway.

Jan 1, 1998

By John S. Harper

Can the mining industry in the United States accept the change and challenge of the "Now Generation" of entirely new high-performance automated transportation systems? Good Question! While there has been some revolutionary new thinking and product testing in mining, none has taken place in transportation of ore and waste. With one notable exception - DASHAVEYOR - not a single really new and 'unconventional' system has even been tried on a small scale in the hardrock mines in our country. Admittedly, U.S. equipment manufacturers share the responsibility for the slow progress in mine transportation systems in our country, since they have provided very litte leadership in design innovation or education. First, let me give you my definition of what is meant by the term "Advanced Transportation Systems". Then I will describe and compare such systems, emphasizing the strong and weak features of each as they apply to vertical and horizontal haulage. I will conclude by establishing the principal requirements for implementation of these types of systems in the mining industry in the United States.

Jan 1, 1969