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By Jack G. Pippenger

The Coteau Properties Co.'s Freedom mine is a surface operation near Beulah, ND that produces more than 13.6 Mt/a (15 million stpy) of lignite. Coteau, a subsidiary of North American Coal Corp., ranks among the largest mines in North America. In 1994, Coteau ranked eighth in annual coal sales, becoming the largest mine outside the Powder River Basin of northeastern Wyoming. However, for the Freedom mine to stand alongside the Powder River Basin heavyweights, Coteau had to overcome several obstacles. These included a coal seam with three-quarters the heating value and overburden-to-coal ratios three times higher than Powder River Basin mines. Coteau's ability to compete has been built around a program of continuous improvements in productivity, cost efficiency and innovation.

Jan 1, 1995

By B. Nyman

A lot of work is in progress to improve copper recovery by leaching-solvent extraction-electrowinning (L-SX-EW). At Outokumpu the focus of attention is on SX equipment development as a result of which a new mixing-settling technology, the Vertical Smooth Flow (VSF) has been introduced. Using helical stirrers in the VSF mixers a more gentle and uniform contacting can be obtained than in the mixing compartments of the low-profile design. The benefits of Outokumpu's new approach are an essential decrease in organic losses and in aqueous in organic entrainments. Separate pumping using a smoothly pre-contacting "Dispersion Overflow Pump" (DOP) is a key feature of the VSF design. The scale-up of this pump as well as the VSF mixers are shown to follow simple mathematical relationships which also have been confirmed by full scale experiments.

Jan 1, 1995

By H. Haas

European coal mines are facing a very difficult situation. Despite a steadily increasing world energy consumption, the sales of European coal mines have been going down and production has to be adapted. The reason is the collapse of energy prices aided by the decreasing rate of U.S. $ to Deutschmark in the last few years. The problems are not due to the development of European mines themselves. Assured energy supplies are an important condition for the health of a nation's economy. Contribution of domestic energy production ensures some degree of independence from world market fluctuations as to supply volumes and price, and maintaining jobs and should be achieved within the framework of economic constellations. Governmental energy programs are planned towards meeting this end.

Jan 1, 1989

By S. Nygren

Nalco Chemical Company and a North Carolina Phosphate operation have formed a successful supplier/customer team effort that has resulted in major improvements in the operation of the clay thickening circuit at the Aurora, North Carolina concentrator. A Nalco OPTICUS® Automated Process Control System for thickener and flocculant control was installed in 1994. The paper will discuss in detail the development and refinement of the OPTICUS system over the past three years. The paper will survey the development and networking of process control for monitoring, controlling and operating four 325-foot Dorr-Oliver thickeners, three 80-foot high-rate Enviro-Clear thickeners and control links to the facility's clay/gypsum blending operation.

Jan 1, 1998

By M. Javier

In business mining, dilution is the result of the operating parameters that occur too often and cause serious consequences to mine performance, questioning TO WHOM BENEFITS DILUTION. Mining persists in changing perception of real meaning of dilution. The lack of interrelation between mineral processes and nature compromises the understanding of dilution; this absence of interrelation occurs due to the misinterpretation of nature, otherwise, Geomimic could be helpful to filling the gap of misinformation. NATURE provides LIMITED metals in low content deposits; it is a challenge to obtain them. Nature never considers dilution. Furthermore, though dilution is a human concept, dilution is accepted and promoted. Reality of dilution is in its errors accumulation that translates into technology level or status applied in nature. It is doubtful that dilution can continue surviving if it is ?meaningless?. It will discourse: Is dilution illegal? If the change occurs in the prediction of mining will prevail a different destiny, it is important to touch the cores of the business; otherwise, it would represent repetition of the same ?negative? effects, as usual. Mining defines many losses during the disturbance of nature, from NPV elaboration to the metal recovery to commerce, demanding BETTER DESIGN. This paper introduces and applies MANAGEMENT BY LOSS, as first steps, to limit risks and uncertainties in mining. As result, the management of dilution will be obtainable under mining practices which promotes its character of SUSTAINABILITY.

Feb 23, 2014

By R. S. Ondrey

MSHA has prepared two pamphlets that provide guidelines for selecting dust control parameters for underground coal mining sections. These guidelines are based on research conducted by the Bureau of Mines and underground studies conducted by MSHA. One set of guidelines is specific for longwall mining operations. Another set of guidelines covers room-and-pillar operations. The guidelines contain a general discussion on the appropriate use of ventilation and water to optimize the control of dust.

Jan 1, 1995

By W. Hu

Traditionally, coarse wolframite ore processing has been done almost exclusively by gravity concentration methods. However, there has been a depletion of rich and coarse ore reserves and a proportional increase in the mining of low-grade, fine-grained complex ore feeds. This change has resulted in the need for better slime-processing technology. Research and development activities in this area have gained momentum, and recent innovations appear promising. This paper covers the recent innovations that have been made in dealing with tungsten ore slime processing. The new techniques include the application of a centrifugal cone separator, high-intensity wet magnetic separator, the use of phosphonic and arsonic acids as collectors in ultrafine wolframite flotation, and combined processes.

Jan 1, 1989

By D. A. Norrgran

The recent development of rare earth permanent magnets has revolutionized the field of magnetic separation. The advent of rare earth permanent magnets in the 1980's provided a magnetic energy product an order of magnitude greater than that of conventional ferrite magnets. This has allowed the design of high-intensity magnetic circuits operating energy free and surpassing the strength and effectiveness of electromagnets. New applications and design concepts focused on the mineral and metal processing industries have evolved. This technology also led to the development of various magnetic separators specifically designed for mineral processing applications. Applications which were not previously considered are now being applied to primary mineral upgrading and recycling and secondary recovery.

Jan 1, 1993

By Ken Goering

"Bridgestone Americas opened the company’s first U.S.-based giant off-road radial (ORR) tire plant in November. The 139,000-m2 (1.5 -million-sq ft) plant, located on a 222-ha (550- acre) site in Aiken County, SC, will produce radial tire products, including 157-cm (63-in.) tires, used on mining and aggregate haul trucks.The plant, announced in 2011 as a $970-million investment, represents the largest investment that Bridgestone has made in the United States, and is also the single largest investment ever made in South Carolina. Although it had already been producing tires for a few months, the plant officially opened with a ceremony in November 2014, attended by South Carolina federal, state and local elected officials, as well as Bridgestone personnel from the United States and Japan. Prior to the Aiken County plant’s construction, all of Bridgestone’s giant ORR tires were manufactured at its Shimonoseki and Kitakyushu facilities in Japan.Kurt Danielson, president of Bridgestone’s U.S. & Canada Commercial Group, said the facility was built to primarily serve the North American mining and aggregate industries in a more efficient manner. "It’s a real change for us," he said of the U.S.-based plant at its opening ceremony. "This allows us to have a true global presence."The Aiken County plant is intended to allow Bridgestone to meet customer demand for ORR tires, Danielson said. "It really frees up our other plants in Japan to service the rest of the world, allowing us to serve our customers faster," Danielson said. "As soon as we build (a tire), we can have it to our customers."Tires manufactured at Bridgestone’s Japanese plants could spend up to a month in transit to the American continents; from initial mixing of the rubber and other compounds to being warehoused, tires manufactured at the Aiken County plant can be ready to ship in four to five days.Danielson said most of the tires built in Aiken County will be used by customers on the American continents. "We will export," he said, "but our desire is to use as much capacity as we can for the Americas."Ground was broken for the facility inSeptember 2011, when commodity prices were much different than today and global demand for tires had skyrocketed."

Jan 1, 2014

By J. V. G. Middleton

The paper gives a comprehensive review of the design considerations which determined the choice of the milling plant, a description of the plant and comment on the operating experience to date. Operating experience will include inter alia a description of the mill liners installed with subsequent changes due to wear patterns, the mill inlet sealing arrangement, steel ball addition, mill outlet sump design, cyclone feed pump liner wear patterns and comment on the efficiency of the linear screens for wood chip and tramp removal. Finally a view on future trends in South African milling practice with respect to type and size of plant.

Jan 1, 1989

By S. Stebbins

In 1994 Western Mine Engineering, Inc., (WME), which is now InfoMine USA, Inc., set out to build a suite of stand-alone software programs that would provide their clients the means to estimate the costs of developing and operating mineral exploitation projects. After the first program (Sherpa for Surface Mines) was completed and launched, the developer (me) left WME to form Aventurine Engineering, Inc., in order to complete the series of applications. In the years since, four programs have either been developed or upgraded and enhanced. Applications were produced that estimate the costs of underground mining, placer mining, and project site reclamation. In addition, an application specifically designed to evaluate the economics of these projects, which was based upon a program previously developed for WME by Bill Willoughby of Willoughby & Associates, was redesigned and the code updated to a MicroSoft compatible platform. All these programs follow an engineering-based approach to cost estimating. Instead of relying on rules-of-thumb and statistical averages, they calculate all of the engineering and operational parameters needed to estimate costs. The premise is that the uncertainty associated with cost estimates should lie with the data available for the resource, not the approaches used to design and estimate the associated design parameters. In other words, it is acceptable that items such as the resource grades, deposit dimensions, ore and wall rock characteristics, and mill recovery rates carry with them some uncertainty, but parameters such as loader bucket capacities, truck speeds, pump horsepowers, hoist velocities, and grinding mill diameters can be calculated (although uncertain data might be used in those calculations). No additional uncertainties should be introduced because the cost-estimating procedure relied upon statistical manipulation or anecdotal inaccuracies. To that end, the programs rely upon calculation-based approaches to selecting and sizing machinery, assigning the required workforce, and determining the extent of the consumables needed to recover mineralized material at a rate defined by the client. And while calculation-based software is not unusual, more modern approaches work toward the development, accumulation, and manipulation of data. INITIAL CONDITIONS AND PROJECT GOALS In 2016 we had five separate programs completely disconnected from one another. Each was written in VisualBasic, a language that was falling from favor. In essence, the status in 2016 was a series of stand-alone programs (Figure 1) in which results from one needed to be manually entered as input into another.

Jan 1, 2019

By T. C. Canter

Technological change is continually affecting the mining industry and the many papers being presented at this meeting reflect this fact. I fully agree that miners must remain fully cognizant of technology that can change mining costs and therefore your competitive marketplace. Despite the embrace of new technology and effective mine management techniques, the mining enterprise may not realize increased net income if the structure of the minerals marketplace is not understood. An important segment of the marketing structure for minerals is transportation. Transportation costs per ton can be much greater than the mining costs per ton and may accordingly overshadow hard earned gains in productivity. Change is greatly affecting the transportation industry but the change is driven more by governmental policy than technology. Although some technological advances are occurring in the bulk transportation business, the changes I want to address arise from policy. Policy changes have come from legislation in the 1970's culminating with the Staggers Act of 1980 and ensuing Interstate Commerce Commission decisions.

Jan 1, 1985

By D. W. Park

Longwall mining is popular in underground coal production in the United States due to higher production rates and safety concerns. Because of the extreme complexity, it is necessary to plan an adequate design to achieve a safe and efficient working place. The proper sizes of yield and abutment pillars and panels can be determined by simulation using numerical modeling techniques. By means of three-dimensional modeling, stresses to be imposed on the pillars, panels, gob, and powered supports can be analyzed. In this study, an initial three-dimensional finite element model was developed and then modified into four different models. Using these models, the numerical outputs of distributed stresses on three different sizes of yield pillars, three different sizes of panels, and two different sizes of abutment pillars were compared and analyzed to determine the most adequate pillar and panel sizes. Progressive failure theory based on the Hoek and Brown failure criterion was used to determine redistribution of stresses in the yielded and failed areas in the longwall mine.

Jan 1, 1992

By L. M. Pruett

The Arizona Legislature is currently in the process of considering mined land reclamation legislation in the 1994 legislative session. A bipartisan legislative study committee has drafted proposed mined land legislation. The committee has attempted to craft legislation that is appropriate for the unique conditions in Arizona. Existing Arizona and federal laws and regulations extensively regulate the environmental performance of mines in the state to protect public health, safety and the environment. The proposed mined land reclamation legislation does not replace or duplicate these statutory provisions relating to environmental protection. Instead, the purpose of the proposed legislation is to provide for the reclamation of land that is being mined and to fill the gap in existing laws by requiring the reclamation of land that currently is being mined or that has been mined since 1986 to provide for future land use. The legislation would require an operator to submit a reclamation plan describing the exploration operations, mining operations, post-mining land use and the proposed reclamation measures for review by a state agency. Financial assurance also would be required in an amount such that a third party could complete the approved reclamation measures. Arizona's mined land reclamation legislation would recognize Arizona's leading role in hard rock mining and emphasize the mining industry's economic importance to Arizona and the nation. Because mining operations necessarily require disturbing the surface of the earth to extract valuable minerals, reclamation requirements would be adapted to different conditions and would vary depending on site-specific conditions and on the commodity being mined. The current proposal does not identify the state agency that will administer the mined land reclamation program and approve reclamation plans, substantial changes to plans, and transfers of reclamation plans to other operators.

Jan 1, 1994

Due to the ongoing restructuring of the mining industry in central Europe with a continuous decline of the number of large underground mines and collieries, and a simultaneous decline of staff numbers in the remaining mines, the established mine rescue schemes are endangered to collapse. With the end of the mine rehabilitation at Wismut Uranium in 2014, the last remaining major mine rescue teams in Saxony, providing basic mine rescue services for all other mines in the region, will disappear. This will leave a large number of small mines and other underground operations without capable mine rescue support. Since none of these companies is able to set up a complete mines rescue unit on its own, new ways have to be found. Among others, a central mine rescue team for central Germany as well as the assistance by special trained professional fire fighters or mine rescue teams from abroad are discussed. Problems like location of the central rescue team, financing, communication and transport have to be solved. This paper provides an overview over the complexity of the problem as an example for other mining regions worldwide and will discuss national and cross-national strategies.

Feb 23, 2014

By P. J. Lechler

A review of the geology and mineralogy of several of the better known hydrothermal platinum-group metal (PGM) deposits is undertaken. Along with new data from two recently discovered occurrences in Nevada, a number of common characteristics of these deposits are identified. Newly described PGM occurrences in Nevada are the abandoned Gibellini mine workings characterized by limestone-hosted hydrothermal Mn-V-Zn-Ni mineralization and the granite-hosted base-and precious-metal veins of the Gingerload claims.

Jan 1, 1989

By Thomas N. Walthier

Exploration is the systematically financed and technically oriented search for mineral wealth. Almost all established mining companies have an exploration department. The size of a company's search varies over the years as the company's profits, or the corporate philosophy change. While the established mining companies have exploration departments, they are also alert to acquiring discoveries made by others -- especially by prospectors and small companies without the resources to develop their find. The emphasis in some large companies stresses self-generated discoveries while others rely heavily on acquisitions; again, over the years the emphasis may alternate. In the last analysis, essentially all new mineral wealth was found through someone's exploration effort. Before we discuss how exploration is financed, it will be informative to analyze how discoveries have been made and by whom. Recently, the author conducted a survey of randomly selected major mining companies to answer these questions. Most companies responded and many went to considerable effort to give complete and detailed answers. I thank all for their help and cooperation. The questionnaire is attached as Appendix I. Appendix II is a list of the 400 companies that replied in a complete enough manner and format to be analyzed here. The results of the questionnaire are given in Table 1. Over 57% of the new orebodies acquired by 40 major mining companies during the past quarter of a century were generated

Jan 1, 1977

By M. Ruonala

The Larox Power PF Pressure Filter has been developed to meet the challenges of ever increasing output tonnages demanded by the minerals processing industry. This paper will highlight recent experiences at the Rudna Copper Concentrator in Poland, the Escondida Copper Concentrator in Chile and some large zinc concentrators in Australia. Detailed maintenance and operating cost information will be disclosed. Emphasis will be placed on economics on scale gained from higher machine throughputs.

Jan 1, 1998

By D. W. Fuerstenau

One of the more energy-efficient methods for size reduction, namely particle-bed comminution under high compressive loads, was employed to grind eight minerals and ores, using up to 250 MPa pressure. A new approach based on the self-preserving character of the ground product size distributions and a linear energy-reduction ratio relationship is proposed for analyzing this mode of size reduction. The grind ability of the material when comminuted in a particle bed is about one-half that of the single-particle crushing mode, which is in agreement with previous estimates of the relative efficiencies of energy utilization based on direct measurements of surface area produced. The loss of efficiency may be attributed to energy dissipation by particle interaction phenomena in compressed beds.

Jan 1, 1993

By Kal V. S. Sastry

Conventional iron ore balling circuits exhibit undesirable surging behavior which is known to result from uncontrolled occurrence of the mechanisms of nucleation, coalescence and layering. This study was undertaken to investigate the mechanism of pellet growth by layering. Several laboratory experiments have been carried out to delineate the effect of feed moisture content and feed quantity. This paper presents an analysis of the experimental results and a simple model to describe the layering process.

Jan 1, 1993