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By Timothy J. Orr, Jami M. Girard

A NIOSH study on occupational deaths between 1980 and 1989 indicated that in the United States, mining had the highest average annual fatality rate (3 1.9 per 100,000 workers) of any other major industry. Since "lack of training" was often cited as the primary cause of accidents, NIOSH has been investigating new methods for effective training. One such method is the use of low- cost, desktop computers to simulate a virtual mining environment. Computer-based training offers several advantages over conventional training because the computer programs provide a three- dimensional environment that allows the trainee to practice using evacuation routes, encounter mining hazards, and view mining operations without being exposed to any real danger. One major focus of the project is mine escapeway multiuser training using desktop virtual reality programs. Researchers have imported mine maps into the software for the purpose of practicing actual evacuation routes and procedures. Various scenarios for evacuation can be practiced in a three-dimensional computer simulation of the mine in a disaster situation, complete with smoke, fire, and other dangers. Depending on the trainee's job description (i.e., foreman, shift boss, beltman, etc.), certain tasks need to be performed in addition to navigating primary and/or secondary escape routes. Each scenario allows for individual or team-based training and provides a means to educate mine workers in hazard recognition and hazard avoidance. Using this program, mine workers can practice evacuating various mine layouts without the danger and expense associated with escapeway training in an actual underground mine. Each scenario can be changed to test the trainee's reaction in a variety of circumstances and run many times so the trainee can practice concepts. This training experience will help reinforce the knowledge acquired during more conventional classroom instruction, and the inherent flexibility of the program allows training materials to be tailored to meet the specific requirements of individual mines.

Jan 1, 2002

By Gary W. Hudiburgh

The gangue in some magnetite ore bodies contains feldspar; the alkali content of the feldspar reduces the usefulness of these iron ores. One method of decreasing the feldspar content in magnetite concentrate is froth flotation. The amine flotation of feldspar from magnetite concentrate was investigated using zeta potential measurements, Hallimond tube flotation tests and laboratory-scale flotation tests. The zeta potential of various feldspars (microcline, albite, anorthite, oliqoclase and anorthoclase) were determined as a function of pH; the point of zero charge ranged from pH 1.4 to 2.5. Hallimond tube flotation tests using two amine reagents were conducted on the feldspars. Hallimond tube flotation tests using six amine flotation reagents were performed on the cobber tails (quartz, albite and microcline) from a magnetite concentrating plant; in all cases, over 85 percent flotation recovery was obtained at pH 8 and 10-5 to 10-4 [M] collector addition. Laboratory-scale (667 grams) flotation tests were performed on the magnetite concentrate in an attempt to float the feldspar which had reported to the concentrate. The effects of three different collectors, two levels of collector concentration, three pH levels, starch and HF acid were investigated.

Jan 1, 1975

By Michael Wortley

Metso?s Process Technology and Innovation group is a world leader in mineral processing consulting. A significant amount of this consulting work involves process integration and optimization (PIO) studies, which include investigating the effects of drill-and-blast design and implementation on downstream processing. Critical to these studies is the ability to track specific ore into, and through, the plant. To increase the accuracy of this ore tracking, Metso Process Technology and Innovation (PTI) developed a system to track ore using a radio frequency identification (RFID) transponders technology designed to allow tracking of ore from its source through blasting, run-of-mine (ROM) pads, crushers, intermediate stockpiles and, finally, into the concentrator. The system is called SmartTag. Since its commercialization in 2007, SmartTag has been used in the majority of PTI?s consulting projects, and several permanent systems have been installed worldwide.

Jan 1, 2012

By Kadri Dagdelen

The importance of factoring mining dilution into feasibility stage ore reserve estimates is discussed. An example that relates the issue of mining dilution to the size of smallest volumes that can be mined selectively is given. Relationship between the size of the selective mining units (SMU's) and the variance of their average grade is presented. The concept of variance reduction and its use in factoring mining dilution into geostatistical ore reserve estimation is described. An approach to estimate variance reduction factor by way of conditional simulation is introduced.

Jan 1, 1996

By Shangyong Lin, Wei Sun, Weiping Liu, Muhammad Azam, Junfeng Chen, Yujie Zhao, David Asubonteng, Michael Ngoie

Copper concentrates are widely used in smelting operations worldwide and typically consist of chalcopyrite ( CuFeS2) as the primary mineral, with chalcocite ( Cu2S) and bornite ( Cu5FeS4) as secondary copper-bearing minerals. However, these concentrates often contain hazardous impurities, such as the fluorine ion, which can result in various complications during the smelting process. These issues include equipment corrosion, gas treatment requirements, environmental hazards, and strained community relations. Furthermore, high fluorine content in copper concentrates can lead to penalties and limitations during sales. To address these challenges, this comprehensive review assesses current techniques for removing fluorine from copper concentrate. Drawing upon recent research and the findings in the field, the review analyzes the advantages and disadvantages of existing fluorine removal methods and identifies critical issues requiring attention in the future. This review provides valuable insights into the current state of fluorine removal from copper concentrates and serves as a practical guide for researchers and industry professionals in this field.

Aug 2, 2023

By W. H. A. Timm

Lake Dufault Mines, Limited, is located ten miles north of Noranda, Quebec. Following discovery of a copper-zinc orebody late in 1961, metallurgical investigations of diamond drill core were conducted by Lakefield Research Limited during 1962 and 1963. These were followed by pilot-plant tests in May and June of 1964, utilizing underground development ore. Milling operations commenced on August 16, 1964, and reached rated capacity of 1,300 tons per day by October 1, 1964 (Figure 1). Since that time, tonnage was gradually increased to a maximum of 1,400 tons per day and since January 1, 1968, gradually decreased to the present rate of 1,100 tons per day due to an increase in the hardness of the ore. The ore milled from start-up until January, 1968, was mainly massive sulphides, consisting of a complex mixture of iron, copper, zinc and minor amounts of lead sulphides with important associated values in gold, silver and cadmium (aver- age specific gravity 3.8). From January, 1968, until the present, the ore being processed is described geologically as a boxwork of sulphide stringers of chalcopyrite, pyrite and pyrrhotite and some local dissemination in siliceous rhyolite (average specific gravity 2.9) supplemented by the massive copper-zinc ore. The limited size of the orebody and the mining method employed (open stoping by blasthole and slash and bench methods) would have made grade control from the mine difficult and expensive. It was decided to try to cope with grade variations in the mill. The resulting rapid and wide swings in mill heads, hardness and specific gravity have presented many and varied challenges for the mill personnel.

Jan 1, 1970

By W. J. Karwoski

A ground-support system for grizzly and haulage drifts was tested in Magma Copper Co.'s San Manuel mine. Eight two-piece, wide- flange steel sets were erected in a ventilation drift on the 2315 grizzly level. The sets were lagged with three different materials and back- packed with pea gravel and sand. The pillar on either side of the drift support system was instrumented with stressmeters and rock-bolt load cells, the backfill with pressure cells, and the steel sets with load cells. Results indicate a better survival rate than with typical monolithic concrete.

Jan 1, 1979

By Liaqat Ali Shah, Muhammad Farooq, Zait Ullah Shah, Francisco Rolando Valenzuela-Díaz

Bentonite collected from Nowshera (Pakistan) was treated with NaCl, and the < 2-μm clay fractions were separated by sedimentation process. The textural changes in NaCl treated purified bentonite were compared with raw and physically purified sample. It was detected that the NaCl-treated purified bentonite and the sample purified by simple sedimentation, respectively, consist of sodium-montmorillonite and calcium-montmorillonite as a major clay mineral. The honeycombed-type morphology was observed for both the purified samples; however, the particles of NaCl treated purified bentonite were relatively in a compact form. The particle sizes of both the purified samples were found considerably smaller. The high volume percent of the fine particles was noticed in the NaCl-treated purified bentonite. This attributed that the sodium exchange has a valuable impact on the bentonite dispersion in aqueous media during particle size measurement. The relatively high mesopore area/volume and micropore area/volume and specific surface area (SSA) were detected in purified samples. The NaCl-treated purified sample showed relatively high mesopores area/volume than the sample obtained by simple sedimentation. These changes seem to be originated from either high montmorillonite contents and/or the smaller particle size, which might be produced after the layer rearrangement during the interlayer cation replacement by Na+ ions. The large SSA and high porosity of purified samples particularly the NaCl-treated bentonite suggest their potential use as adsorbents, catalysts, pharmaceuticals, and cosmetics.

Jan 7, 2021

By Hoke M. Garrett

The domestic cement industry demands about 550 trillion Btu annually, at a time when reduced fuel use has become a necessity due to the energy shortage. In terms of the overall power picture, that 550 trillion Btu, which includes both fossil and electrical energy, means about 0. 870 of all energy consumed in the U. S. The various factors influencing reduction of this energy consumption are the subject of this paper. Nationally, the energy shortage is being tackled on two fronts--increasing supply and reducing demand. Making cement consumes energy; therefore, the industry cannot join the effort to increase the energy supply except indirectly as noted later. Demand can also be attacked on two fronts--by reducing cement consumption or by reducing the amount of energy required to make cement. The following discussions on reducing cement industry energy consumption center briefly on the prospect of reducing cement consumption followed by a broad evaluation of the potentials for improving cement-making thermal efficiency.

Jan 1, 1974

By John Barakso

The Sam Goosly or Equity silver deposit is fundamental- ly a discovery based on the analysis and interpretation of reconnaissance geochemical samples. The discovery was made by Kennco in an area of heavy forestation and wide- spread cover by thin glacial debris. No major mines had been discovered in the vicinity of the discovery prior to the geochemical reconnaissance, and the interpretation of the geochemical results therefore was based on data available through geologic mapping and the sample collection process. In the period 1959-1961, PE. Hirst and his crew, in 1962- 1965 P.T. Blackand his crew, and in 1966-1967 C.S. Ney and P.T. Black and their crew collected geochemical samples from the area of what is now the ore body. Several of these samples were compiled and reanalyzed in the winter of 1966- 1967 for various trace elements, including fluorine. A strong, almost 16-sq-km (10-sq-mile) fluorine anomaly was projected along with a very weak heavy metal anomaly. On the basis of this anomaly, a chalcopyrite-bearing quartz monzonite was discovered in 1967. This was a misleading, noneconomic discovery not associated with the Sam Goosly discovery. The interpretation of the geochemical data by Barakso that summer indicated that another source was responsible for the fluorine anomaly. The conclusion was based on the assemblage of trace elements. Therefore C.S. Ney recommended further regional soil sampling to check the original data. The early results of this follow-up sampling found over 33 ppm silver. First float, then ore outcrop was found in the area of the silver anomaly. The attached reprints complete the development of the property after the discovery of the outcrop of ore.

Jan 1, 1990

By Sandeep Kumar Jeripotula, Govinda Raj Mandela, Aruna Manglapady

Dozer operators are frequently exposed to whole-body vibration (WBV) during the execution of their work. Occupational exposure to WBV in Indian surface coal mines was evaluated by measuring vibration intensity and duration of exposure. A triaxial accelerometer was placed on the operator seat surface for taking the readings. Based on frequency-weighted root mean square acceleration equivalent to 8-hr shift duration, i.e., (A(8)) all dozer operators have exceeded an Exposure Action Value (EAV) of 0.5 m/s2 , and 90% of dozers did not exceed Exposure Limit Value (ELV) of 1.15 m/s2 . Based on Vibration Dose Value (VDV (8)), all dozer operators have exceeded Exposure Limit Value (EAV) of 9.1 m/s1.75, but no dozer operators have exceeded Exposure Limit Value (ELV) of 21 m/s1.75. Further, an epidemiological study was performed for identifying the extent of musculoskeletal disorders (MSDs) among dozer operators. For the detailed study, 42 dozer operators and 22 controls were selected from 2 surface coal mines. The control group was not exposed to WBV. It was seen from the cross-sectional study that pain in the lower back was predominantly higher (83.33%) in the exposed group when compared with the control group (31.81%). Likewise, pain in the neck (47.61%), shoulder (42.85%), knees (42.85%), and ankle (11.90%) was higher in the exposed group than that of the control group (22.71%, 0%, 45.45%, and 4.54%). A significant observation among the exposed group was that there was degradation in the quality of life. The outcome of the study would assist in monitoring and mitigation of machinery-induced vibration diseases (MIVD) in India and generally applicable to most of the mechanized mines as well. However, comprehensive studies are still needed to enunciate the magnitude extent.

By L. Wilfley, G. A. Calboreanu

"Wear resistant 25% Cr hard cast iron is a heterogeneous material containing 1,600 HV hard chromium carbides embedded into martensitic matrix. It is the most used cast alloy in wear operations of mining industry, chemical industry, fracking, etc. During the last decade the hard iron manufacturers increased wear resistance in the following ways: • Reduce / eliminate harmful retained austenite and chromium + carbon depleted areas especially within eutectic carbide cells. In Max5A the improved 25% Cr alloy brittle carbide eutectic cells are removed which increases toughness. • Delay delamination between chromium carbides and matrix particularly during sliding abrasion wear. Delamination commences at the weakest chromium carbide – matrix contact lines exposing chromium carbide to localized bending stresses which gradually chip carbides away. Once the chromium carbide base is removed accelerated wear degradation occurs. • Evenly randomize and avoid discontinuities in the chromium carbide network. When chromium carbides are perpendicularly positioned to the wear surface wear rate is minimized. On the contrary the highest wear rate takes place when 3D oriented chromium carbides are parallel with the wear surface. In this case chromium carbides cover top network discontinuities being just matrix supported which leads to rapid carbide cracking. The new hard iron discussed in this paper fulfils and exceeds the above requirements increasing the casting service life around 250% in various wear operations. Physical and mechanical properties of Max5A are compared with well manufactured Industry Standard 25% Cr hard iron. The paper presents practical accomplishments obtained in the USA, South America and India. INTRODUCTION The chemical composition of Max5A and Industry Standard 25% Cr are identical like specified by ASTM A532 Class III Type A requesting C = 2.0-3.3% and Cr = 23.0-30.0%. Manganese, silicon, nickel, molybdenum and copper contents are limited by maximum accepted quantities.[1] According to published data the eutectic chromium carbides chemical composition of 25% Cr hard iron is Cr = 54% and C = 8% which indicates strong depletion of chromium and carbon along chromium carbide - matrix interfaces. [2] The optimized Max5A microstructure has minimized retained austenite, is devoid of harmful carbide eutectic cells and has the most advantageous chromium carbide and secondary chromium carbide morphology. This favorable microstructure increases wear resistance, mechanical properties and corrosion resistance. The paper compares the Max5A microscopic features and mechanical – physical properties with similar properties of high quality Industry Standard 25% Cr."

Jan 1, 2017

By C. Vasilescu

Phytotechnologies use plants to remediate various media impacted with different types of contaminants. These technologies can be implemented either in situ or ex situ. The affected media in which phytotechnologies can be applied include soil, sediments, groundwater and surface water. They are best applied at sites with shallow contamination of organic, nutrient, or metal pollutants that are amenable to one of five treatment options: phytoextraction, phytotrans-formation, rhizosphere, bioremediation, phyto-stabilization or rhizofiltration. Phytoremediation can be used along or, in some cases, in place of mechanical cleanup methods. Phytoremediation can be used to clean up metals, pesticides, solvents, explosives, crude oil, polycyclic aromatic hydrocarbons and landfill leachates.

Jan 1, 2006

By S. A. McGhee

ASARCO Incorporated embarked on a modernization and expansion program to improve overall operating efficiencies and to more effectively develop the large mineral reserve at the Ray Complex Open-Pit Mining operation located near Kearny, Arizona. Major elements of this Ray Modernization and Concentrator Expansion Project included engineering and construction of a 54,400 MTPD (60,000 STPD) In-Pit Crusher and Overland Conveying System. and a 24,200 MTPD (30,000 STPD) Copper SAG Concentrator and Tailings Disposal System. Detailed engineering, procurement, and construction management were initiated in November 1989 under contract with Bechtel Corporation. Field construction commenced in May 1990 leading to mechanical completion and start-up during February 1992.

Jan 1, 1993

By J. A. Marts

Reservoir properties including porosity and permeability distributions in longwall coal mine gobs have direct application to modeling the flow patterns and gas distributions in the gobs. Proper assessment of these distributions is required to assess gob gas hazards such as spontaneous combustion and explosive methane mixtures and to optimize gob gas venthole operation and nitrogen inertization. Determining the reservoir properties is difficult given that the gob is inaccessible and direct measurements cannot be easily taken. Several techniques had been used by previous researchers and will be discussed. This paper will present the methodology used to model the gob compaction by simulating the sequential extraction of coal. Two Western US coal mines were used for case studies. By determining volumetric strain, the porosity and permeability distributions in the gob can be calculated. The geo-mechanical model predicts an axisymmetric volumetric strain distribution with a steeper slope near the start-up room and a shallower slope near the active face.

By L. A. Readdy

Defining classes of ore using geostatistical methods that match historical classifications has presented problems in the past. A simplistic and practical approach to this problem is presented. An example of the approach is presented using a porphyry type system as a case study. The technique described uses area of drill hole influence and known conditions from similar deposits, or the production history of the deposit being studied. It provides a practical bridging mechanism for defining the class of ore on a block-by-block basis using .the error of estimation value developed during kreiging. The approach provides a filtering method that refocuses attention on the adequacy of drill hole spacing.

Jan 1, 1985

By Erwan Yap, Brian Mangogna, Craig Romrell, Jeff McKay, Weishi Mang, Andrea Deml, Adam Steimel, Justin Dix

The Doe Run Company (Doe Run), a global supplier of lead (Pb), copper (Cu) and zinc (Zn) concentrates, and lead metal alloys, installed an enterprise expert control system— termed as Digital One—on the company’s Pb, Cu and Zn circuits at its Buick Mill in December 2022. Digital One was developed with Metso and deploys Metso’s product, VisioFroth™. This automated system is now running and optimizing the flotation processes for all three circuits (Pb, Zn and Cu), all plant air and methyl isobutyl carbinol (MIBC). In addition, Digital One also controls a second, newly built, modern flotation reagent system. Digital One also paves the way for automation and expert control of the entire mill, integrating grinding, thickening and filtration. Digital One is digitally immersed in a universal distributed control system (DCS); therefore, today’s mineral processing plants may be upgraded to it or designed around it. This presentation will explore the plant design and operation of this technology at the Doe Run Buick Mill.

Feb 1, 2024

By S. Tan

In this paper, several commonly used computer truck dispatching criteria are evaluated. A computer-oriented truck dispatching and production simulator was developed to provide data for comprehensive cross comparison among the dispatching criteria. The definitions, primary considerations, characteristics, and performances of these dispatching criteria were investigated. From the simulation results, it was concluded that, in general, no one criterion can dominate all others. All basic dispatching criteria including minimizing truck waiting time, minimizing shovel waiting time, minimizing truck saturation, maximizing truck momentary productivity, or truck routes optimization provide a local optimal solution. To obtain a direct global optimization solution for this complex stochastic process does not appear to be likely. Therefore, the search for an optimal dispatching criterion that will fit all conditions may not be realistic. However, based on the simulation results of the mine operation, several dispatching criteria which have good potential to increase performance can be selected. It may be necessary to search for the best combination of these truck dispatching criteria for a given situation. For example, a truck flow measurement such as the truck clustering factor at shovels can be used as a switch parameter to change from one criterion to another. The values for the switch parameter at which actions should be taken to change the criterion can be established through simulation programs.

Jan 1, 1992

By J. D. McAteer

It is widely agreed throughout the mining community that federal mine safety and health legislation administered by the Mine Safety and Health Administration (MSHA) deserves significant credit for the past quarter-century&apos;s remarkable improvements in miner safety and health. Recently, however, it has been suggested that the mining industry in the United States has now evolved to a point that current mine safety and health law may be obsolete. This proposition deserves attention. Today, I propose to give it the close logical scrutiny that is its due. I conclude that the obsolescence of current mine safety and health law is not supported by the evidence. The existing mine safety and health law continues to serve as a critically important supplement to mine operators&apos; safety programs at a modest cost to the taxpayer. At the same time, trends in a changing industry do call for responsive adaptations in the Federal mine safety and health program. I will argue that timely and appropriate responses to changing needs can be accomplished within the framework of existing legislation, provided federal officials avail themselves of the flexibility provided by existing law.

Jan 1, 1996

Sphalerite is commonly floated in an alkaline environment and under such conditions the overall activation mechanism is obscured by the hydrolysis of Cu2+ and precipitation of Cu(OH)2. Electrokinetic and kinetic flotation tests show that the activation of sphalerite is a two-stage process; the activation products formed on the surface of sphalerite in near neutral and in alkaline solutions in the first rapid activation stage are "flotation-inactive". These layers, when formed in an alkaline solution, are unstable and are transformed into the "flotation-active" form in the second stage. However, the surface layers formed during activation in alkaline environment by copper in the presence of lead ions are very stable and even after a long conditioning time the flotation rate is not improved. Consequently, while both Cu2+ and Pb2+ activate sphalerite flotation, quite unpredictable effects may result when both are present in the solution.

Jan 1, 1997