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By Kim Lapakko

Increasing public concern over the welfare of the environment has placed demands on the mining industry to evaluate the environmental impact of mining development. This is a difficult task and involves considering the influence of a multitude of variables on complex processes over a long time period. Few studies which focus on the evaluation of the environmental impact of mining have been conducted and, therefore, there is little past experience to rely upon. This article describes some of the work done to evaluate the potential environmental impact of mining development in Minnesota. Interest in developing the major copper and nickel sulfide deposits near the wilderness areas of northeastern Minnesota aroused concern regarding the environmental impact of mining development in the region. As a result laboratory and field studies were initiated to investigate the potential for trace metal leaching and acid generation due to dissolution of Duluth gabbro. Chemical equilibrium computer modeling was conducted to aid in data interpretation. The goals of the study included the investigation of leaching mechanisms and rates of release (1, 2).

Jan 1, 1980

By A. D. Davis

Naturally occurring arsenic has been detected in water from inactive mines and several wells in the Keystone area of the Black Hills. Keystone City Well #4 showed a total arsenic concentration of 69 parts per billion (ppb) during pumping in 2004. The well is not used currently except for arsenic-removal research. Water also can be pumped from a mine shaft in the abandoned Keystone ? Columbia ? Bullion gold mines, whose interconnected workings flooded after mining ceased in the 1930s. This water has been considered for local supplies, although it would require treatment or blending because of arsenic concentrations. According to historical records, the Bullion Mine produced 100,000 pounds of white arsenic. An aquifer test on the mine workings was performed at a pumping rate of about 550 gallons per minute. The arsenic concentration in pumped water was 33 ppb. In addition to wells within Keystone, samples from the water supply at nearby Mount Rushmore National Memorial have shown arsenic concentrations greater than 10 ppb, the U.S. Environmental Protection Agency?s maximum contaminant level for arsenic in drinking water. Limestone-based technology for removal of arsenic from drinking water is an innovative and promising method that has been considered for treatment of water at Keystone. In batch testing with water from Keystone Well #4, limestone removed about 65% of arsenic from solution. A related problem of arsenic removal from drinking water involves disposal of the waste product, which is critical for commercial viability of removal technologies. Current research is investigating thermal stability of the waste in order to determine the potential for recycling of the material during manufacture of cement.

Jan 1, 2010

By J. Harrison Daniel

Were the legislators and politicians responsible for the closing of the U.S. Department of the Interior?s Bureau of Mines (Bureau) in March 1996 fully aware of what they were doing? Throughout the United States? history, the domestic mining and minerals industry has been largely responsible for the nation?s growth and prosperity that had made it a world leader. The mining and minerals industry made it possible for the young nation to catch up with Europe during the Industrial Revolution, played an essential role leading to victories in World Wars I and II and was a core ingredient for continued economic growth. For a number of decades, America?s import dependency on non-fuel mineral materials has continued to increase. (USGS Mineral Commodity Summaries). Developing domestic resources to meet current and future demands ? particularly those resources considered to be of strategic and critical value to national security ? is necessary. Federal involvement is required since many of these resources are located on public lands. Another reason for federal involvement is that the success of the industry depends on long-range research programs and advances that may take up to 25 years to become commercially available. This situation requires federal partnership to coordinate the programs necessary to collectively involve the industry, individual mining companies and colleges and universities. So, how was it possible to close a federal agency that had contributed so much to the nation?s welfare in a mandated 90-day period, with more than 1,200 employees losing their jobs?

Jan 4, 2010

By David Jurich, Ed Perko, Jacob Prezkuta

Numerous Colorado mountain tunnels that date to the late 1800s convey water to the farming and urban communities of the eastern Front Range. Repairs to these remote facilities, often located in public lands at altitudes of 11,000 feet or more, require detailed planning, close coordination with multiple agencies, and creative execution. Issues and solutions discussed include designing repairs in undocumented ground and support conditions, logistical challenges, work in a short summer construction window, stabilization of historically signicant structures, and proect delivery strategies. xamples that illustrate early contractor involvement, exibility in design, and construction solutions are presented.

Jun 23, 2024

By John Barber

The Deep Ore Zone (DOZ) Mine is PT Freeport Indonesia's (PTFI) newest operation. Production at the mine began in September 2000. The DOZ Mine produces 25 kt/d (27,500 stpd) using mechanized block cave mining methods. The DOZ Mine has several major improvements when compared with previous block cave mines in the district. It has an independent and improved ventilation system, a flexible and efficient truck haulage system, and a more reliable crushing and conveying system. PTFI's copper and gold mining complex is located in the Ertsberg mining district in Irian Jaya, Indonesia (Fig. 1). The Ertsberg district is located in the Sudirman Mountains at elevations from 3,000 to 4,500 m (9,800 to 14,700 ft) above sea level. The topography is extremely rugged and rainfall in the mine area averages 3,000 mm/a (118 in./year). Freeport began production in the district in 1972 when the mill began processing ore from the Ertsberg openpit. Underground mining began in 1980 when the Gunung Bijih Timur-Ertsberg East (GBT) Mine was brought online using block caving methods. In 1991, the GBT Mine reached a maximum production rate of 28 kt/d (31,000 stpd). Ore from the mine was exhausted in 1994. The Intermediate Ore Zone (IOZ) was brought into production in 1994. It, too, used block caving methods and had a design rate of 10 kt/d (11,000 stpd). The IOZ is currently producing at a rate of 21 kt/ d (23,000 stpd). The DOZ was discovered in the mid-1980s by deep drilling from the GBT. The GBT, IOZ and DOZ deposits are all situated in the Ertsberg East Skarn System (EESS). In 1993, the first of several studies was completed that indicated that portions of the DOZ Mine could be economically mined using block caving methods. Limited development was started in 1995. Full-scale development and construction began in late 1997. The crusher and conveying system began operating during the first quarter 2000. The first of two main exhaust shafts has been com¬missioned, along with three of the four new main fans. The second exhaust shaft and fourth main fan will be in service by the end of 2001. Undercutting and production began in September 2000. The DOZ Mine will reach its design production rate of 25 kt/d (27,500 stpd) in 2003. A study is under way to determine if an ultimate production rate of 35 kt/d (38,500 stpd) is feasible.

Jan 1, 2001

By E. Cameron

Yeelirrie lies toward the center of Western Australia, 650 km (404 miles) northeast of Perth (Fig. 1). The ore reserves have been estimated as 52.5 kt (57,871 tons) of contained U3O8, at an average grade of 0.15%, of which almost two-thirds average 0.24% U3O8. the ore body is a thin, elliptical, more or less horizontal sheet measuring approximately 9 km (5.6 miles) in length, between 0.5 and 1.5 km (0.3 and 0.9 miles) in width, and up to 7 m (23 ft) in thickness, extending from the surface to a depth of 8 m (26 ft). In spite of its near surface position, there is only one small outcrop of significant mineralization. Carnotite is the only uranium mineral recognized so far, dispersed through a calcrete horizon, and deposited from circulating ground water which was also responsible for the carbonation of the clays completely filling an Early Tertiary drainage system. Calcrete, as seen at Yeelirrie, is quite distinct from the widespread, thin pedogenic horizons, as it often forms bodies many kilometers in length and up to 20 m (65.6 ft) in thickness, elongated parallel to the drainage lines. It is variously referred to as "valley calcrete" or "ground water calcrete" to emphasize the occurrence and mode of origin. The discovery of Yeelirrie in mid-1971 was the successful culmination of a grass-roots exploration program initiated in 1968 as part of Western Mining Cop's program of diversification from its historical position as a major gold producer. The object was simply to find an economic uranium deposit - with no constaints other than those normally taken as applying in the mineral search. There was, therefore, complete freedom in the selection of the exploration model, or models, to be applied and the areas to be considered, though the choice was inevitably influenced by both the nature of world occurrences and the local geology. One of the options avail- able was the sandstone environment. Yeelirrie was the direct result of pursuing this line of investigation through three sequential, but quite distinct, stages: first, a regional study; second, establishing a case for exploring the inland drainage systems of Western Australia; and finally, an evaluation of the calcrete environment. An assessment of the potential for sandstone-type deposits in Australia necessitated going back to first principles, since there were no known precedents in this country for guiding exploration and, as a consequence, the search need not be influenced by established prejudices. Previous uranium exploration during the 1950s had been preoccupied with vein-type deposits, and, although the sandstone environment was undoubtedly being examined in 1968, no discoveries had been announced to that time. When considering the necessary ingredients -a source of leachable uranium, a circulating ground water system, and a suitable reducing environment - it could be argued that considerable areas in the eastern part of the continent were theoretically prospective, but basin depth and the extensive superficial cover of Mesozoic and Cainozoic sediments presented considerable practical difficulties.

Jan 1, 1991

By Francis J. Kiessling

Energy and the conversion of potential energy into alternate forms is becoming a topic of household conversation for a larger segment of the world's population as mankind's desire for products derived from the vast array of technological developments continues to expand. The world's use of steel and the high energy consumption related to the production of steel promotes an awareness of the limitations of existing technology and a search for more economical alternates. Terminology such as (BF) Blast Furnace, (BOP) Basic Oxygen Furnace, (EAF) Electric ARC Furnace, (DR) Direct Reduction, (DRI) Direct Reduced Iron and (FC) form coke is becoming commonplace as alternates are being sought to alleviate the energy crunch. Coke production by various methods was developed as early as the seventeenth century in Europe to replace the disappearing hardwood forests that supplied the initial blast furnace fuel in the form of charcoal. In 1880, the Semet Solvay by-product coke oven design was introduced to the United States at Syracuse, New York, to supply coke for use in the production of soda ash, coke oven gas and its by products as the primary source of many organic processes. Although the Semet Solvay coke oven has not been marketed for decades, these coke oven batteries are in use today producing metallurgical coke, coke oven gas, and related by-products.

Jan 1, 1980

By K. Marutiram, T. Umadevi, R. Sah, K. Abhishek

Low-grade iron ore received from the West Singhbhum area of Jharkhand state in India was used to develop a beneficiation flow sheet to remove alumina (Al2O3) and silica (SiO2 ) from the ore to get iron (Fe)-rich product for steel plants. Mineral characterization showed that the main mineral constituents present in the head sample are goethite, limonite, hematite, quartz, clay and gibbsite. The head sample contained about 49.2 percent Fe, 8.79 percent alumina and 12.01 percent silica. The received iron ore sample is amenable to upgradation through beneficiation to get pellet grade concentrate. The beneficiation process was established, involving crushing, screening, jigging, spiral separation, size reduction, desliming and magnetic separation. The process showed significant enrichment in Fe values to 63.5 percent Fe in concentrate, from 49.2 percent Fe. From the developed flow sheet, it is possible to obtain pellet grade fines with 63.5 percent Fe, 2.92 percent SiO2 and 2.61 percent Al2O3 with 50.6 percent weight recovery. The overall tailing loss is 49.4 percent with 34.3 percent Fe, 21.28 percent SiO2 and 14.64 percent Al2O3

By Jan M. Mutmansky

Simulation is a general term which commonly appears in the technical literature and which can have different meanings to different people. One interesting definition (9)* applicable in an engineering context is the following: "Simulation is the use of a model to study a problem." In most cases, the model referred to in the above definition is a simulation model constructed in a computer language and implemented on a computer in order to solve the problem under consideration. The application of computer simulation models to the study of problems in materials handling and earthmoving has been successful in the past. Generally speaking, this method has been used where the system to be studied has many variables and where the ability to predict the outcome of the system under different sets of conditions is difficult. The prime reason for using such a model is to evaluate the numerous likely ways of operating any particular system without the necessity of actually conducting full-scale field tests. The simulation model presented here is such an application made to the process of tunneling and, in particular, to the process of tunneling with a boring-type tunneling device. At first glance, the process of tunneling may not appear to be particularly complex and susceptible to study by a computer model. However, a close analysis of the tunneling process will reveal that it is rather complicated as a result of limitations placed upon the system by restricted space in the tunnel, geologic variations along the tunnel

Jan 1, 1972

Improvements in computer technology and associated software have allowed the improvement and development of more advanced ventilation modeling software packages including those that have the ability to simulate the effects of a mine fire on the ventilation system in terms of heat, smoke and gas distribution. This ability has real applications for the mining industry in terms of emergency planning, training and response. The primary focus of this paper will be the benefits to training programs that this type of software can provide to all types of training for various personnel, from the newly hired inexperienced miner, mine rescue, atmospheric monitoring personnel and emergency evacuation drills. The results of the simulations can then be used to give miner?s more detailed information on what types of conditions they may face based on the type and location of the fire and the program itself can be used to manipulate the ventilation system in a way that emergency response personnel may (i.e. tear down stoppings to reduce airflow to the fire area) and see the effects in real-time.

Jan 1, 2012

The mining industry, like most other industries, has had a difficult couple of years. What are your thoughts on the industry?s direction in the next few years? I am bullish on our industry. There is no question in my mind that the quality of life we enjoy today is largely a result of our past successes in the minerals and mining sector. I am equally certain that the sustainability of that quality of life and the aspirations of the rest of the world to attain that same level of lifestyle will depend hugely on our future successes and will be the driver for our industry to continue to excel and prosper. Surely, there are going to be challenges along the way. These challenges are not only from the public, regulators and various governing bodies, but also from our industry?s own self regulating efforts. However, we have demonstrated throughout the past several decades that we have the capability to meet these challenges head on and come out ahead.

Jan 3, 2010

By Steve J. Czehura

The Butte quartz monzonite is the host rock for early porphyry copper style mineralization and subsequent mesothermal-epithermal, enargite-gold style veining that transects the district. The east-west Anaconda system veins sustained mining for over a century. They include the Emma, Anaconda-Original, Syndicate, Badger-State and Alice-Rainbow veins, each with strike lengths of more than 3,660-m (12,000-ft) and vertical continuity in excess of 1,370-m (4,500-ft) with mining widths from 1.5- to 15-m (5- to 50-ft). These characteristics are unique to Butte. The incredible dimensions and tenor of these veins have yet to be surpassed and Butte is still touted as being the “Richest Hill on Earth.” The Anaconda Company was formed in 1895 to develop underground copper reserves in the district. It eventually consolidated all operations under one company. Production from underground mining continued through the mid-1970s. Openpit mining in the Berkeley pit began in 1955 with the extraction of supergene ores, along with the remnants of deeper horsetail zones inaccessible to the underground mines.

Jan 1, 2006

By V. E. Housman

EPA's Mining Waste Section within the Office of Solid Waste is continuing to collect and analyze information on mining waste management practices. Starting in 1991, the Mining Waste Section has continued to conduct site visits and prepare case study reports on the waste generation and management practices of operating mines. In choosing sites to study, a reasonable attempt was made to provide diversity in mining commodity types, geographic regions, geology, climate, and environment. To date, EPA has visited the following mines: Asarco Troy (copper) in Montana, Newmont Rain in Nevada (gold), Cyprus Thompson Creek (molybdenum) in Idaho, LTV Steel (iron) in Minnesota, Phelps Dodge Morenci (copper) in Arizona, Doe Run Fletcher (lead) in Missouri, Brewer (gold) in South Carolina, IMC Four Corners (phosphate) .in Florida, Pennzoil Culberson (sulfur) in Texas, Nerco Cripple Creek (gold) in Colorado, Copper Range White Pine (copper) in Michigan, Magma San Manuel (copper) in Arizona, Colosseum (gold) in California, and several gold placer mines in Alaska, including the Valdez Creek Mine. EPA has prepared a case study report on each facility. The mine operators were provided an opportunity to comment on their respective site visit report and their comments have been included in' each respective report. These site visit reports have in turn been incorporated into technical resource documents which provide a detailed description of each mining sector. EPA is currently reviewing the technical resource documents and plans to release the documents in the Spring of 1994.

Jan 1, 1994

By D. C. Fuller

CoaLiquid, Inc. (CLI) has been in the coal- oil-mixture (COM) business for over five (5) years. The initial pilot processing facility was replaced by a 2000 barrel per day commercial production facility in August of 1979. For over two (2) years CLI has been expanding its efforts and conducting large scale production and combustion demonstrations successfully in many locations across the United States. To facilitate the marketing effort, CLI has recently constructed a special trailer containing all equipment needed for a temporary COM retrofit. CoaLiquid has conducted commercial scale combustion demonstrations in the following types of combustion units: kilns, calciners, industrial boilers, blast furnaces and driers.

Jan 1, 1982

By A. Halim, J. Gustafsson, A. van Wageningen, J. Johansson, · J. Lööw, K. Kocsis

A major part of the European Union’s (EU) project Sustainable Intelligent Mining System (SIMS) is investigating the development of diesel-free/carbon–neutral underground mines in order to ensure sustainable underground mining in the future. Replacing diesel machines with electric vehicles in underground hard rock mines has been widely acknowledged by the mining industry worldwide as a critical step to improve working conditions by reducing diesel exhaust–related contaminants, to reduce mine ventilation electrical power cost by reducing mine airflow quantity, and to reduce mine greenhouse gas emissions. All of these are major requirements to achieve sustainable future underground mining practices. A field trial of Epiroc’s 2nd generation of Battery Electric Vehicles (BEVs) at Agnico Eagle Finland’s Kittilä mine was conducted during 2019–2020. Vehicles tested were MT42 mine truck, ST14 Load-Haul-Dump (LHD), and Boomer E2 jumbo drill rig. This paper outlines the improvement of the working conditions observed in the field trial, and the opinions of the mine personnel at Kittilä mine on using BEVs instead of diesel machines. Measurements of atmospheric contaminants and air temperatures taken during the field trial clearly demonstrated a significant improvement of working conditions when BEVs were operating as opposed to diesel machines. This field observation was supported by the opinion of the majority of the Kittilä mine workers. However, some remaining concerns must be addressed before BEVs can replace diesel machines.

Oct 25, 2021

Once every three years the eyes of the construction and mining industry?s turn to Munich, Germany for the bauma trade fair and exhibition. From April 19-25, Messe München International (MMI) will host the 29th edition of this massive show that, despite the recent recession and global financial struggles, has grown yet again. The show, which is completely booked, will take place on a record 555,000 m2 (5.9 million sq ft) of indoor and outdoor exhibition space at the New Munich Trade Fair Centre. More than 3,000 exhibitors are expected to make use of this event. To prepare for the show that highlights some of the largest and most impressive construction and mining equipment in the world, Messe München began working months in advance on getting the infrastructure on the open-air site ready, in time for the arrival of the gigantic machinery exhibits, which started to arrive in March. Part of the preparations include a new entrance at the northwest corner of the exhibition center that was built to regulate visitor flow better. This should help with bauma considering that in 2007 more than 500,000 visitors passed through the gates. ?Although in 2010 the construction machinery sector in many markets worldwide will be recovering only slowly from the recession, we are pleased to report that we are seeing strong demand for exhibition space. This shows that exhibitors regard participation in the world?s leading trade fair bauma as a must, although many are at present having to make cuts in their advertising and trade-fair budgets. We have been particularly surprised by the strong demand for space from exhibitors from markets like China, India and Turkey. The fair is fully booked and many more companies are on the waiting list,? said Eugen Egetenmeir, managing director of Messe München. More than 50 percent of the exhibitors at bauma 2010 come from countries outside of Germany. While the show?s primary focus is on the construction section, it is not as if the mining sector will be difficult to find. With some of the largest equipment in world on display in section C2 (Fig. 1), the mining industry is sure to be well-represented.

Jan 4, 2010

Asgco’s design of the Arrowhead Ceramic Lagging provides solutions to problems experienced with conveyor belt slippage around the drive pulley and severe wear problems on snub and bend pulleys. Asgco has developed a range of pulley lagging from ceramic, drive rubber and non-drive rubber lagging that is available in abrasion-resistant SBR and MSHA grade rubber for conveyor pulleys from slow belts all the way through to high-speed, high load belts. There is a growing need for a maintenance-free and reliable pulley lagging to ensure conveyor belts run to their highest efficiency.

Jan 1, 2006

By MUSTAFA ERKAYAOGLU, ENVER YILMAZ

Coal mining is likely to sustain its critical role as energy requirements are increasing. While surface mining exploits coal seams near the surface, underground mining techniques are crucial for extracting deep coal reserves. Longwall mining is one of the most common methods used in underground coal mining operations. This paper introduces a data-based framework — including data collection, data analysis and the interpretation of operational data — for understanding the system efficiency of a longwall shearer. Operational performance is evaluated by the time between arrivals (TBA) and duration of the shearer stoppages, shearer drums’ reversal time, cutting speed and flit speed on daily production in a longwall top coal caving (LTCC) mine. A discrete event simulation model is developed to represent the bidirectional cutting sequence of a longwall shearer.

By Robert C. Maxton

The foundry industry is a basic source of structural component for all industry. Millions of tons of castings are produced annually in both ferrous and nonferrous alloys. These castings are subjected to a wide variety of heat treatments, finishing techniques, mechanical tests and machining operations. Through all of these steps the quality of the casting is of paramount importance to the end use of the product. The Quality Assurance Program at Minneapolis Electric Steel Castings Company is designed and established to provide a superior product for both original equipment manufacturers and the mining industry.

Jan 1, 1982

By Nathan Bowersox, Zuzana Skovajsova, David M. Jurich, Brian Harris

When unwatered after more than 50 years of operation, the White Rock Tunnel of the Upper American River Project in the foothills of the Sierra Mountains exhibited failing rockbolts and ground falls. Repairs designed for the 5 mile-long, 24-foot horseshoe unlined hydropower tunnel included pattern rock bolts, shotcrete, and cleanout of the rock trap. The work, originally scheduled for two 3-month winter outages, was completed under challenging conditions in a single 4-month outage following a carefully sequenced work plan using robotic shotcrete and rockbolter machines. Flexibility, creative solutions, and collaboration by all parties were key to project success.

Jun 13, 2021