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By M. Kumral

A mining system consists of many sub-systems such as drilling, blasting, loading, hauling, ventilation, hoisting and supporting. During mining operation, these sub-systems may experience various problems that stop the operation because of possible environmental equipment and safety issues. In order to ensure delivery contracts in the required quality and safe mining medium, the operation should be, at least, performed in the specified reliability level of the system. If the system reliability decreases below the specified level, there will be safety and financial losses for the mining company. Therefore, the mine should be maintained by a reconstruction procedure to guarantee the operation continuity. Given that each sub-system has a different reliability function and maintenance cost, the determination of reconstruction time will be a complicated decision making problem. In this paper, the determination of reconstruction time is formulated as a nonlinear optimization problem and solved by genetic algorithms (GA). A case study was conducted to demonstrate the performance of the approach for an underground operation. The results showed that the approach could be used to determine the best action time. Keywords: mining system; genetic algorithms; reconstruction time; reliability analysis

Jan 1, 2009

By Pengfu Tan

Electric arc furnace (EAF) dust from the steel industries is listed by the United Sates EPA as a hazardous waste under the regulations of the Resource Conservation and Recovery Act due to the presence of lead, cadmium and chromium. The disposal of the approximately 650,000 tons of EAF dust per year in the U.S. and Canada is an expensive and unresolved problem for the majority of steel companies. The Waelz process has been considered as the best process for treating EAF dust. A process model, combined thermodynamic modeling with heat transfer calculations, has been developed to simulate the chemical reactions, mass and heat transfer and heat balance in the kiln. The injection of air into the slag and the temperature profile along the kiln has been modeled. The effect of (CaO+MgO)/SiO2 on the solidus temperature of slag has been modeled also and discussed. Some optimizing results have been presented in this paper.

Jan 1, 2005

By Dupuy. Leon W., R. T. C. Rasmussen, W. A. Calhoun

"INTRODUCTION For many years it has been known that low-grade manganese deposits occur in the bluffs along the Missouri River Valley. Frequent attempts have been made to develop the ore and to produce a marketalble commodity but they have had little success. Under pressure of the war emergency and the shortage of manganese, the attention of the Federal Bureau of Mines was directedtoward the deposits.Manganese-bearing shale occurs from a point near Pierre, S. Dak., down the river to the Rosebud bridge near the Nebraska line (1).5/ The Bureau of,confined its work to the more accessible central portion of the deposits near Chamberlain, S. Dak. The ore occurs principally as concretionary nodules in the form of iron and manganese carbonates (manganosiarite and perhaps some manganocalcite; rhodochrosite has not been identified). At the surface the carbonate is often broken down so that the oxide of manganese gives the nodules a black The matrix or host rock is generally known as Pierre shale, composed of ""interbedded layers of bentonite, an altered volcanic ash, and dissemi¬nated bentonite particles,"" (2) and montmorillonite-beidellite clay minerals (3). The shale weathers to the very sticky gumbo characteristic of South Dakota and well-known to hunters and travelers in the area.The area selected for the experimental mining and pilot-plant work discussed in this report lies about 8 miles westerly from Chamberlain and is a few hundred feet north of U. S. Highway,16, on land owned or controlled,by M. Q. Sharpe of Kennebec, S. Dak., and the General Manganese Corp."

Feb 1, 1946

By E. S. Leaver

The gold that is not recovered by a particular process is refractory to that process. A study to determine how the refractory gold is associated in the ore constituents usually indicates the needed improvement in the process or additional methods for bettering recovery. In preliminary work, segregation of the various minerals, gangue or impurities, and data showing the reactions of each in the recovery method readily confines the refractory gold to a certain part on which extensive research can be directed. In this dissecting plan, the microscope is an important aid in locating the refractory gold but should be supplemented by chemical tests.

Jan 1, 1934

By Jeffrey A. Schaefer

The Olmsted Locks and Dam project is located on the Ohio River approximately 16.5 miles upstream of its confluence with the Mississippi River. It consists of twin 1200 ft. locks with floating and fixed approach walls, five 110 ft. wide tainter gate bays, a 1400 ft. wide navigable pass boat operated wicket gate section, and a 400-ft. section of fixed weir (Fig. 1). The project will have a total cost over 1.0 billion dollars, and as such is one of the largest civil works project underway in the Corps of Engineers.

Jan 1, 2001

By Verya Nasri, Agustin Rey

Once completed, the Montreal Réseau Express Métropolitain (REM) will be the fourth largest automated transportation system in the world. The REM represents construction costs of approximately 7.0 billion Canadian dollars. The project consists of 67 km of twin tracks over four branches connected to downtown Montreal. The project includes 26 stations with 3 underground stations in downtown Montreal. One of the underground stations was built using the NATM method with thin permanent shotcrete initial and final liners separated by a sprayed on waterproofing membrane. The 2 other underground stations were built with the cut and cover approach including one using permanent secant pile wall with permanent walers and struts as the support of excavation and the final perimeter wall of the station. The project also includes the rehabilitation and enlargement of the Mont Royal Tunnel. This 100-year-old double track tunnel is about 5 km long. The REM also consists of 3.6 km new TBM tunnel connecting downtown to the Montreal International Airport through saturated soft ground and karstic rock. By the time of RETC, the construction of REM underground structures will be completed. This paper presents the design and construction aspects of the underground structures of this mega project.

Jun 13, 2023

By Dennis McLaughin

This report contains a description of the contract activities performed by ENSCO, Inc. under contract No. H0178069. The purpose of this project was to enhance the Bureau of Mine?s Cableless Electronic Survey System use to aid in the drilling of long (approx. 2000 feet) boreholes in coal. This drilling is performed as part of the methane drainage program. The system that was ultimately developed was field tested 2nd demonstrated in actual in-mine drilling activities. The significance of this system as compared to previous drill survey systems is the fact that it surveys without having to be inserted and removed for each survey point. It is so designed that it can withstand the shock and vibration experience by the drill string during drilling. This means an increased productivity is now possible in that drill operators can determine drill bit positioning in a near real-time environment.

Jan 1, 1981

By C Roche, G M. Mudd

The Morobe Province of central Papua New Guinea (PNG) has been mined for gold for nearly a century, although it is only in the past decade that large-scale modern mining commenced. The Hidden Valley gold-silver project began construction in mid-2006 and production by August 2009, and is located in the mountains above Wau in the headwaters of the Watut River. The mine is owned and operated by the Morobe Mining Joint Venture (MMJV), which also owns the Wafi-Golpu project, comprising the Wafi gold deposit and Golpu copper-gold deposit, situated in the Watut River Valley. Together they represent a potential mine of the scale of Ok Tedi or Bougainville or bigger. The MMJV is owned in equal shares by Newcrest Mining from Australia and Harmony Gold from South Africa. Although Hidden Valley was the first large-scale mine in PNG to engineer and build a tailings storage facility, poor environmental management during construction and early operations led to significant erosion of waste rock and sedimentation impacts throughout the ~200 km length of the Watut River. Since then, substantial efforts have been made to improve environmental management, especially waste rock placement and storage and water quality management. While the impacts from the Hidden Valley project appear to be reducing, the saga has heightened concerns by many along the Watut River and across PNG about ongoing impacts from mining.This paper presents the results of an ongoing project in the Morobe Province conducted by the Mineral Policy Institute examining the historical, current and future impacts of mining, including community views, social and environmental impacts and the monitoring and regulation of mining. Overall, there is a clear need to more fully integrate social and environmental issues into life-of-mine planning and go above and beyond regulatory requirements. In this way, some of the lessons learnt – by the community, MMJV and government – can be incorporated before, during and long after mining.CITATION:Mudd, G M and Roche, C, ?2014. Mining in Morobe, Papua New Guinea – impacts, assurance and self-determination, in Proceedings Life-of-Mine 2014 , pp 313–336 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D. Kachongo, Y. Cheng, A. Kashala, D. Samal, G. Mitshabu

Many copper processing flowsheets in the Democratic Republic of Congo include the leaching of oxide ores containing copper and cobalt, copper solvent extraction, copper electrowinning, and precipitation of cobalt salt. Recently, cobalt price gained momentum, driven mostly by the fast-growing electric vehicles battery market. The ore blending scenarios tend to prioritise high cobalt grade ore, whatever the content of copper and other impurities. Therefore, many copper solvent extraction circuits are running below design capacity. The variability of feed induces a variability of the leach solution with respect to copper, manganese, and silica contents. It is thus important to adjust hydrodynamic and metallurgical parameters of the solvent extraction plant to optimise metallurgical performance, production cost, and the quality of the copper electrolyte. This paper presents some results on how solvent extraction plant parameters have been managed in two solvent extraction plants running with lower than designed copper input. INTRODUCTION Referring to a report of the chamber of commerce of the Democratic Republic of Congo (DRC) the online publication Agence Ecofin (2019) indicated that the DRC ranks in the fifth position of the world top copper producing countries with over 1.2 million tons produced in 2018. The same year, 66% of the world’s cobalt was produced in the DRC at over 106,000 tons. If the political situation remained stable and the new tax regime introduced in 2018 did not deter private investors, copper production could reach 1.4 million tons/a in 2020 as pointed out in Mining.com (2019). Forecast figures for DRC cobalt production vary widely depending on analysts. The DRC online magazine Actualité.cd (2018) referring to a ministerial source forecasts over 141,000 t cobalt/a for 2020. The reality will depend on many factors, including the selling price, the supply compared to the demand, and finally the reaction of investors to the new DRC tax regime. The growing electric vehicle batteries market has been the major key driver of the price of cobalt. The five years historical cobalt price graph in figure 1 from infomine.com (2019) shows that the price of cobalt peaked at over 40 USD/lb in the first quarter of 2018. Cited by the online Magazine Creamer Media, Smith (2019) has indicated that the long-term demand of cobalt will likely remain strong.

Jan 1, 2019

By Albert L. Toenges

Early in 1944 the Chilean Government expressed a desire for assistance from the Bureau of Mines in a study of the coal deposits, coal-mining methods, and preparation and benefication of coals in Chile. A Memorandum of Understanding setting forth the purpose of the work was executed by the United States Government and the Government of Chile. Parts of this agreement are quoted: On February 4, 1944, the Ambassador of Chile in Washington expressed the interest of his Government in obtaining the loan of a mission of experts to assist in the conduct of a survey looking toward the utilization of the low-grade coals of Chile and the application of such technology as may be developed for the distillation of these coals and the use of oil shales. The matter has since been the subject of correspondence between the Secretary of State and the United States Department of the Interior, and the latter Department has agreed to cooperate with the Government of Chile, through the Bureau of Mines, subject to the following understanding:

Jan 1, 1948

By J Geronimo, P Kumar, Z Yussupova, M Yahyaei, M Powell

This work goes beyond the general perception of how the well-known mine to mill process can be applied, by applying deeper knowledge along the mining chain. Grade deportment and dilution are considered at the mining stage, and modelled with the new SMI blast movement simulator, linking with the block model data. Assessing the shift to a considerably more competent section of the orebody is quantified via substantial milling trials at standard and higher-intensity blasts. These were stockpiled for batch processing through the mill to ensure feed integrity. The trial work included operating the mill at widely different fillings to develop Grindcurve milling responses. Additionally, model informed process control is initiated via a mill prediction tool.It has been found that accounting for blast movement for the higher intensity blasts could generate additional value of around $1.5M per blast. With the high-intensity blast and changing mill control, the plant was easily able to exceed projected mill throughputs with the far more competent Pipeline ore. Strategies to shift the workload and debottleneck the milling circuit were proposed and proven during the milling trials, demonstrating an increase in throughput of 7 per cent despite running at a lower SAG mill speed, and potential of 16 per cent for increasing the SAG mill to standard operating speed. A number of process improvement opportunities have been identified to enhance current productivity and ensure long term capability to process the considerably more competent future ores. All of this is being linked in with the major digitisation program at the Barrick Cortez site, with an objective of linking all the data into a mine-wide process optimisation system, that can embed the processes by providing process-wide data access and production support via the future dynamic models linking ore body knowledge to productivity along the full process chain.CITATION:Powell, M, Yahyaei, M, Geronimo, J, Yussupova, Z and Kumar, P, 2018. The designed approach to mill liner optimisation – experience at Pustynnoye mine, Kazakhstan, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 595–612 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Jim Gunderson

Jan 1, 2004

By W. D. Striffler

Land disturbed by surface mining in Colorado and other western states has increased substantially over the past several years and is likely to increase even more in the future. This study was initiated to provide basic information on hydrologic and erosional characteristics of regraded coal spoils in Colorado as an aid for planning future reclamation activities. Eleven of twenty-one surface mines licensed in Colorado were sampled during the summer of 1980 and 1981. Mines not sampled included mines which had not progressed to the point that reclamation had begun, and mines where operators denied permission to sample. All coal regions were sampled with the exception of the San Juan Coal Field. Physical and hydrologic characteristics of regraded coal spoils in Colorado were determined using standard field and laboratory procedures. Field sampling included characterization of sites (slope, vegetation density, proportion of surface rock, bare soil, etc.) and infiltration measurements using a l-meter square drop former raining on a 1/2 square meter rectangular plot frame. Core samples collected in the field were analyzed for saturated hydraulic conductivity, bulk density, organic matter, moisture retention and texture. The erosion potential of each site was determined using the Universal Soil Loss Equation (USLE). Results of the sampling indicate that infiltration rates vary widely both within and between sites. However, definite trends with respect to coal fields are apparent. For example, the Green River (Yampa) coal region had a wide range of sampled infiltration rates (1.2 to 5.1 cm/hr). However, most of the sites clustered towards the low end of the range. The North Park (Marr Strip) also was rated at the low end of the infiltration range (2.0 to 3.0 cm/hr). Average infiltration rates for the Canon City and Uinta Coal Regions were at the high end of the range (4.9 to 5.5 cm/hr). Multiple correlation analysis of infiltration rates vs. site characteristics showed that infiltration rates were most closely correlated with the depth of wetting, the amount of mulch cover, and site slope. The depth of wetting was highly correlated with the depth of the topsoil and the bulk density of the spoil. In general, the topsoil at all sites appeared to be highly permeable to water intake but once saturated, subsequent infiltration depended upon characteristics of the underlying spoil. Vegetation cover affected infiltration on individual mine sites but was not as pronounced as topsoil characteristics or mulch. Erodibility of topsoil and spoils, as determined by Wischmeier's "K" factor, ranged from 1.34 to 0.56 tonnes/ha. (topsoil) and 1.25 to 0.66 tonnes/ha. (spoils). Definite trends in erodibility are evident. The Green River (Yampa) Coal Region displayed consistently higher erodibilities (1.34 to 0.75 tonnes/ha.) than other coal fields (0.72 to 0.56 tonnes/ha). Lowest erodibilities were observed in the Uinta, North Park, and Raton Mesa Coal Regions (0.56 to 0.62 tonnes/ha). Erodibilities of underlying spoils showed similar trends as the topsoils. Erosion potential (the product of soil erodibility and rainfall erosivity) was detennined using calculated ?K? factors and rainfall erosivities (R) taken from Clyde (1976). Results show that the Delagua coal field, Raton Mesa Coal Region had the greatest erosion potential due to the high rainfall energies in the region, while the North Park and Uinta Coal Regions had the lowest potential erosion.

Jan 1, 1981

By Arthur Notman

TO present some idea of the magnitude of the gold-mining industry of Canada and the world, the records of 106 gold-mining companies currently paying dividends have been studied. Forty of these are in Canada, and 37 on the Rand in South Africa, these being all the straight gold-mining companies that paid dividends in the two areas in 1938. None of the base-metal companies that produce gold as a by- product, or even as a major fraction of the value of their total product, have beezl included. In addition, a group of 29 similar companies from Southern Rhodesia and the Gold Coast in Africa, India, Australia, Manchuria, Philippine Islands, the

Jan 1, 1939

By Sushil Bhandari, Amit Bhandari

Blast optimization in open-pit operations is a task that often remains at a theoretical stage. Indeed, when it comes to operational blast design and onsite implementation, time restrictions and field conditions make it difficult to execute a planned pattern accurately and optimization according to local conditions is even more difficult. For example, adjusting a drill pattern to a complex face geometry is not something that can be easily undertaken on site. Blasters and engineers will do their best trying to distribute boreholes over the bench and even then, it can take them hours to achieve an acceptable layout. Similar situations occur with delay sequences, when trying to adjust them to address selectivity or vibration issues. For these reasons, operational blast design will often remain at a very basic level and the required adjustments are laid aside due to the difficulty of implementing them on site.

Jan 1, 2019

By F. D. Everett

The Federal Bureau of Mines reviewed the status of tungsten deposits of Utah in 1959. Industrial requirements of tungsten during emergencies have exceeded the domestic supply, and a knowledge of the sources of this strategic element may be helpful in the future. Tungsten occurs as the mineral scheelite in deposits that have been developed or explored on approximately 60 properties in 10 of the Great Basin ranges of Utah, none of which were being worked in 1957-59. Ores from most of the productive areas are similar in that they are contained in tactite deposits on or near the contact of calcareous and acidic intrusive rocks. The tactite ores consist predominantly of the silicate minerals garnet, epidote, and diopside and the carbonate rocks limestone or dolomite. Scheelite, where present, is disseminated irregularly in the tactite. Tungsten ores from Utah mainly have been produced from small deposits worked in World Wars I and II and the Korean campaign. The ores were either hand sorted to a grade ranging from 0.5 to 1.0 percent tungsten trioxide (W03) or were beneficiated in small mills to higher grade concentrates. The largest reserve appears to be in the area of the Notch Peak intrusive in the House Range, Millard County. A large part of the reserve in the House Range is mineralized tactite containing 0.2 to 0.3 percent W03. Research on flotation by the Bureau of Mines has indicated a method of concentrating scheelite in tactite ores that average 0.25 percent W03, with at least 85 percent recovery. The concentrate assays more than 5 percent W03 and can be processed into artificial scheelite ready for industrial use.

Jan 1, 1961

By D. Nag, J. Fernando

Hazelwood Power Mine is one of the largest open pit brown coal mines in Australia. The removal of overburden is the first step in coal winning operation. The primary aim of construction of overburden dump is to provide an effective stable working surface for stacker. The paper discusses site investigation techniques used to determine dump soil properties, stability analysis method using GALENA and GWEDGEM, results of stability analysis. The paper concludes with recommendation for a safe dumping strategy for level 2 stacker dumping.

Jan 1, 2003

By J. Wagner, P. Eger, G. Melchert

In 1991, LTV Steel Mining Company decided to close an open pit taconite mine in northeastern Minnesota, using a passive treatment approach consisting of limiting infiltration into the stockpiles and wetland treatment to remove metals. Over 50 million metric tons of sulfide-containing waste had been stockpiled adjacent to the mine during its 30 years of operation. Drainage from the stockpiles contained elevated levels of copper, nickel, cobalt and zinc. Nickel is the major trace metal in the drainages, and prior to closure annual median concentrations ranged from 1.5-50 mg/L. Copper, cobalt and zinc are also present but are generally less than 5% of the nickel values. Median pH ranges from 5.0 to 7.5, but most of the stockpile drainages have pH greater than 6.5. Based on the chemical composition of each stockpile, a cover material was selected. The higher the potential a stockpile had to produce acid drainage, the lower the permeability of the capping material required. Covers ranged from overburden soil removed at the mine to a flexible plastic liner. Predictions of the reduction in infiltration ranged from 40% for the native soil to over 90% for the plastic liner. Five constructed wetlands have been installed since 1992, and have removed 60-90% of the nickel in the drainages. Total capital costs for all the infiltration reduction and wetlands exceeded $6.5 million, but maintenance costs are less than 1% of those for an active treatment plant. Since mine drainage problems can continue for over a hundred years, the lower annual operating costs should pay for the construction of the wetland treatment systems within seven years.

Jan 1, 1999

By E. J. (Kirk) Conway

Thirty-five years ago underground coal mining equipment consisted of simple but rugged machines powered by electric motors and hydraulics. The machines were maintained by maintenance personnel armed with a basic knowledge of hydraulics, electricity, and mechanical design. Over the years the the machine has been transformed into powerful complex mining systems. The maintenance burden has also increased. During this period significant advances have been made in maintainability engineering and system design techniques. Many of these innovations and techniques are applicable to the design of underground mining equipment. The objectives of this project were to; (1) determine the extent to which maintainability design concepts and principles have been applied to the design of underground coal mining equipment, (2) try to assess the impact of equipment design for maintenance on productivity and safety, and (3) develop a maintainability design guideline to enhance the design of new or rebuilt equipment. An equipment design review was completed at ten operational coal mines. Interviews were also conducted with mine management, safety, and maintenance personnel to identify machine specific design advantages and problems. Visits were also made to six original equipment manufacturers to discuss the design of their equipment for maintenance. Volume I presents an overview of the protocol used and a summary of the findings. Volume II includes the maintainability design guide for underground mobile mining equipment.

Jan 1, 1989

By Clinton C. Knox

To demonstrate the feasibility of unwatering ore reserves previously indicated in the virgin Melrose zinc-lead field in Kansas and Oklahoma, the Bureau of Mines .carried through a pumping project on the Park Walton farm in 1943. Due to success of the undertaking, attention was turned to exploration of other indicated ore deposits and promising areas within that part of the field benefited by .the drainage project, By the middle of 1946, four private mining companies were active in the field; and a considerable output of lead and zinc concentrate had been obtained from the new Park Walton mine and mill. The Park Walton Ore deposit was unwatered by installing deep-well pumps in three holes previously drilled by the lessee. Pumping was continued by the Bureau of Mines at a rate of 2,500 to 1,000 g.p.m. for about 6 months; during this time the local static artesian water-level, originally averaging 108 feet below the surface in the old drill holes was lowered to the 316-foot level, which justified beginning the initial shaft sinking and mine developments. In all, about 750,000,000 gallons of water was pumped by the Bureau of Mines at an operating cost averaging $0.024 per 1,000 gallons.

Jan 1, 1948