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By Robert J. Timko

This U.S. Bureau of Mines study examined spontaneous heating episodes in coal mine pillars in an active underground coal mine. The information obtained from these incidents was then analyzed to learn which sampling methods provided the earliest indication of pillar heating. The objective of this study was to discover if the location of future events of pillar spontaneous heating could be inferred from the available information. The spontaneous heating-prone area in this evaluation involved pillars located just inby the mine portals. Several detection methods were used to determine gas levels outside as well as inside the affected pillars. It was hoped that, by incorporating external and internal sampling methods into an organized pro-gram, locations undergoing spontaneous heating could be determined more readily. This study found that by drilling small-diameter boreholes into the pillars, then obtaining gas samples from the affected pillars, the ability to locate early spontaneous heating episodes was improved. However, the ability to accurately predict future spontaneous heating events remains in question.

Jan 1, 2010

By E. Chin

The countries of Asia and the Pacific have large resources of diverse minerals. Australia and China have extensive mineralization that are commercially being exploited. The major minerals in Australia with known reserves adequate for both domestic demand and export markets include bauxite, clays, copper, diamond, gold, iron ore, lead, manganese, mineral sands (titanium minerals), nickel, salt, silver, tin, uranium, and zinc. China is the world leader in proven reserves of antimony, barite, magnesite, molybdenum, rare earths, titanium (ilmenite), tungsten, and vanadium. It also has about 55 billion tons of iron ore, albeit with an average grade of only 30 % to 35 % elemental iron content. With the exception of chromium and copper, China has significant resources of a wide array of minerals and metals, based on its production and/or export capability for these commodities. Additionally, India has significant resources of bauxite and mineral sands; Indonesia, bauxite, copper, nickel, and tin; Malaysia, tin and associated titanium; Mongolia, copper, fluorspar, and lead-zinc; New Caledonia, nickel; New Zealand, gold and iron sand; North Korea, magnesite; Papua New Guinea, copper, gold and mineral sands; Philippines, copper, chromite, and gold; and Sri Lanka, gemstones. Moreover, there appears to be extensive mineralization III Burma (Myanmar), Cambodia, Laos, Thailand, and Vietnam, but they have yet to be definitively delineated.

Jan 1, 1994

By H. E. Powell

The magnetic susceptibilities of 34 manganese-bearing minerals were determined. The source of each sample and petrographic, spectrographic, and chemical analyses are given. Included are values for ismorphous series showing wide ranges of composition and for a few high-purity synthetic minerals.

Jan 1, 1968

By L. J. Cunningham

I THINK it can be safely said that no mining operation, whetl1er open-pit or underground, is ever entirely free of water. It follows that every ton of ore bears a charge which represents, either directly or indirectly, the cost of keeping the mine workings as dry as possible. Water problems occur in all phases of mining operations. They cause difficult and costly drilling conditions during the exploration stage, they often seriously delay mine development, they can slow mine production and reduce efficiency, and they are a continued burden over the life of the mine. It is therefore in the interest of all mining men to be familiar with the methods and materials used for grouting. The most common grouting material is cement. Cement grouting is old and well established, and many engineers are familiar with its uses and limitations. The technique of cement grouting is relatively simple and fairly well understood, and the materials utilized are relatively in-

Jan 1, 1962

"Far from being eclipsed by petroleum and natural gas, Canadian coal continues to command wide (and apparently growing) interest.Major R & D investigations are currently heavily oriented toward coal beneficiation (e.g., cleaning and utilization of fines) and toward a broad range of studies on metallurgical coals and cokes. However, active work is also being carried out in the areas of coal geology, mining, transportation and combustion; and, in some laboratories, increasing stress has been laid on developing a number of new, essentially non-fuel uses for coal and coal products.This review summarizes the work of Canadian coal research agencies during 1966 and indicates some of the more important advances made by them."

Jan 1, 1967

Located 350 km west of Sydney and 20 km outside Orange, NSW, lies the Ridgeway Gold Mine û NewcrestÆs flagship Underground Gold Mine. Key to success at Ridgeway has been the fast tracked development of the 3.8 km, 1 in 5.3 conveyor decline which houses the 850 t/hr conveying system feeding the dedicated Ridgeway Concentrator, built adjacent to the existing Cadia Hill Concentrator. Eroc was contracted to develop the steep conveyor decline, drawing on its personnel and experience from past metalliferous, tunnelling and coal mining projects to complete the ambitious schedule within 12 months. This paper deals with the complexities and experiences in safely delivering what is understood to be one of AustraliaÆs steepest declines of any substantial length in a metalliferous mine.

Jan 1, 2002

By L. Chunpongtong

ABSTRACT The mining limit in oil sands is regulated by the ratio of total mining volume (ore, interburden, and overburden) one has to mine per volume of bitumen in place (TV/BIP). This paper presents a mathematical solution for creating the most economical pit outline where the TV/BIP ratio upper limit is 12, by combining mining economic theory and the Lerchs-Grossmann (LG) algorithm.

Jan 1, 2014

By L. Chunpongtong

The mining limit in oil sands is regulated by the ratio of total mining volume (ore, interburden, and overburden) one has to mine per volume of bitumen in place (TV/BIP). This paper presents a mathematical solution for creating the most economical pit outline where the TV/BIP ratio upper limit is 12, by combining mining economic theory and the Lerchs-Grossmann (LG) algorithm.

Jan 1, 2014

By Wei Victor Liu, Omer Faruk Ugurlu, Chengkai Fan, Bei Jiang

The accurate prediction of truck productivity plays a pivotal role in improving the efficiency and profitability of open-pit mining operations. However, predicting truck productivity is challenging owing to the complex nature of the working conditions of the mine site. This paper proposes a deep neural network model to overcome the challenge of predicting truck productivity in open-pit mines. The prediction model was built using eight variables and was optimized by considering different train-test split ratios, numbers of hidden layers and neurons, and activation functions. The proposed model's performance was evaluated using various metrics and was compared with other commonly used machine learning algorithms. According to the results, the proposed model outperformed traditional machine learning algorithms by achieving higher accuracy and lower error rates, with the best-performing model having four hidden layers with 70 neurons per layer and a scaled exponential linear unit activation function, resulting in a coefficient of determination value of 0.89. This demonstrates the potential of deep neural network models for predicting truck productivity in open-pit mine sites. Moreover, a single variable sensitivity analysis was conducted to investigate the impact of input variables on truck productivity. The results show that haul distance is the most influential variable for the prediction of truck productivity.

Feb 12, 2024

By Saul J. Esdalera

The flotation response to amine collector and its adsorption on the mineral surface was studied as a function of pH and collector concentration. The flotation response increased in the order anorthite + intermediate plagih clases + albite, while adsorption of amine obeyed the Freundlich equation r = A.Cn. This adsorption is proposg to be due to a covalent bonding between the AlOH surface pups of the plagioclase altered outer layer and the amino group of the collector. Finally, the study showed thatmtial dissolution of the solid phase provides the necessary conditions for amine attachment on the mineral particles and consequent flotation.

Jan 1, 1980

By W. R. Hardwick

This paper describes mining methods and practices of the Chino Mines Division, Kennecott Copper Corp., Grant County, N. Mex. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. A similar program was conducted from 1928 to 1939, which helped to improve the efficiency of mining operations. The primary purpose of the program is to promote development and conservation of our mineral resources by disseminating technologic information on methods, practices, and related features in mining mineral deposits. It is expected that the program will: (1) Promote efficiency in operating mines; (2) assist operators and engineers in evaluating and developing new mineral deposits; (3) provide data for engineering curriculums in mining schools; and (4) furnish performance and cost data for revising engineering handbooks and for inclusion in engineering textbooks.

Jan 1, 1958

By W. Z. Rogers

U.S. feldspar output sold or used in 2004 was estimated to be 790 kt (871,000 st), valued at $43 million free-on-board plant. This was below 2003 and about the same volume as 2002. The strong housing market in the United States maintained demand for ceramic tiles, plumbing fixtures, and fiberglass insulation requiring feldspar and shipments of glass containers increased by about 4 percent. Imports of ceramic tiles and plumbing fixtures continue to increase, taking the place of U.S. produced goods, and the feldspar required to make them. Output included flotation concentrates, feldspar content in feldspar-silica mixtures, potash feldspar and aplite.

Jan 1, 2005

By W. R. Reed, G. W. Luxbacher

Mine worker exposure to respirable coal dust and silica dust can result in coal workers’ pneumoconiosis and silicosis which are occupational respiratory diseases that have no cure and are ultimately fatal. In 2021 the Mine Safety and Health Administration reported just over 11,000 operating metal/nonmetal mines with the potential for silica dust exposure for just under 200,000 miners. The National Institute for Occupational Safety and Health (NIOSH) conducts respirable coal and silica dust research associated with mining through its Office of Mine Safety and Health Research. NIOSH respirable coal and silica dust research began under the U.S. Bureau of Mines (USBM), which initially examined silica dust, progressing to include coal dust, with a stronger focus after 1969 with the passage of the Federal Coal Mine Health and Safety Act. A review of extramural research to develop real-time respirable silica dust monitor is presented along with a brief history of silica dust regulation.

Feb 1, 2024

By J. Schenck

Goldcorp Inc. has mining operations and exploration projects throughout Canada, the United States, Mexico, Guatemala and Honduras; as well as partnerships in Argentina and the Dominican Republic. In rural areas of developing countries it is very common to have mining operations surrounded by diverse communities consisting of people with limited, or no formal education. This is fertile ground for anti-mining NGOs to cultivate. The limited educational backgrounds of the people, coupled with a company desire to maintain a low profile can lead to a problematic lack of trust between the local communities and the mining company. As part of its commitment to environmental stewardship and sustainable development, Goldcorp has implemented various programs to build trust at these operations, as well as incorporating this policy into any new projects prior to commencement of operations. This paper is intended to describe two initiatives that have shown positive results for both the communities and the Marlin Mine.

Jan 1, 2009

By Jr. Smith

Borates have been mined in the desert areas of California and Nevada for more than 100 years. To about 1890, playa surface mining provided the chief sources of boron minerals. Underground mining of colemanite and later of borax and kernite was predominate until about twenty years ago. Open pit mining of the large deposits of borax and kernite near Boron, California has been most significant for the past twenty years. Mining of colemanite in the Ryan, California area, near Death Valley, began in 1907. Following the discovery of the large deposits in the Boron area (about 1957), mining in the Death Valley area became nearly nonexistent. Only small tonnages were mined for special uses. Little mining was done in the Boraxo area near Ryan. The first claim was made in about 1915 In 1960 the area became the property of the Kern County Land Company, which was acquired by Tenneco Oil Company in 1967. In 1976 the various borate properties and claims in this region were acquired by American Borate Corporation. The open pit mine is now approximately 400 feet (121.9 m) deep, 3000 feet (914.4 m) long and 1000 feet (304.8 m) wide. The borates in the Boraxo pit consist primarily of three minerals. These are about 50% coiemanite (C2B6O11' 5H2O), about 40% probertite (NaCaB5O9.5H2O), and 10% ulexite (NaCaBcO9.8H2O). The colemanite, along with boric acid and high-grade coiemanite ore from Turkey provide the only sodium-free borates for production of textile grade fiberglas. When heated to its decomposition temperature, colemanite decrepitates to a fine powder. This provides the basis for the concentration process. The gangue minerals in this deposit are primarily calcite and clays, including bentonite. The ore body has a very low arsenic content.which is a desirable feature. Test work had been done with samples prior to the results discussed herein. This paper will discuss results of test work which were the basis for erection of a plant, and the subsequent plant operations.

Jan 1, 1978

By F. Habashi

Brazil is a major mineral and metal producer, has magnificent fauna and flora, and superb architecture. In 1693 gold was discovered in Ouro Preto and Brazil produced about half of the world's gold. In 1726 diamond was discovered in the region of Tijuco in the Province of Minas Gerais, 150 km east of Bello Horizonte. The country became independence from Portugal in 1822 as the Brazilian Empire. In 1876, an Englishman succeeded in obtaining from the Amazon region seeds of rubber trees and secretly transferred them to England, where they were planted in the royal gardens at Kew. Some of the seedlings which spouted were sent to Ceylon and Singapore. Thus, began the rubber industry in the East. Today, Brazil is the largest producer of niobium, and produces a large number of other metals. The Mineral Research Center in Rio de Janeiro is the countries main Government establishment for mineral research. The country has been a republic since 1889 with its capital in Brazilia.

Jan 1, 2009

By Ramsden AR, French DH

The limited contrast range of conventional black and white imaging does not enable full use to be made of the dynamic range of the video signal obtained from a scanning electron microscope or microprobe. The use of false colour substantially increases the information that can be derived from such images enabling relationships to be displayed that cannot be observed in black and white. This capability is now used extensively in combination with quantitative electron microprobe analysis as a research tool for ore characterization and host rocks studies related to minerals exploration in the CSIRO Division of Exploration Geoscience.

Jan 1, 1989

By R. W. Van Dolah

The Bureau of Mines t.ced its investigations into sympathetic detonation of ammonium nitrate (AN) and ammonium nitrate-fuel oil (AN-FO) to define the scaling law for safe separation from detonating AN-FO. Both missile- and non-missile-producing AN-FO donors, weighing up to 5,400 pounds, were employed with acceptors of the same size. The usual cube-root scaling law was not confirmed; exponents for the relationship S = f(Wx) for AN were 0.51 with non¬missile-producing donors and 0.61 for missile-producing donors. For AN-FO an exponent of 0.80 was indicated in the missile-producing case. AN-F0 in polyethylene bags appeared somewhat more easily initiated than bulk AN-FO. The efficacy of barricades in protecting AN charges was investigated. detonation distances were reduced from one-third to one-seventh when filled barricades were employed. The investigation was extended to dynamite with both types of donors. With 1,600-pound missile-producing donors and an equivalent weight of dynamite, initiation would be expected in 50 percent of the trials at 167 feet. The corresponding value in the non-missile case was 67 feet. The data developed in this program of sympathetic detonation will allow the development of a rational set of safe separation distances for AN, AN-FO, and explosives.

Jan 1, 1966

By James R. Boyle

The value of Alabama's nonfuel mineral production in 1987 was $446.6 million, an increase over that of 1986 and the first increase in 3 years. Alabama was second in the Nation in production of bauxite and ferroalloys; third in bentonite, crushed dolomite, crushed marble, and fire clay; and fourth in masonry cement. Trends and Developments.-Employment in the minerals industry remained relatively low for the second year even though the overall unemployment rate dropped to 7.9% by December. Employment in mining and primary metals dropped about 10% and 2%, respectively.

Jan 1, 1989

By S. G. Hardcastle, C. K. Kocsis

Ventilation is an expensive prerequisite for underground mining. Current mining trends, including increasing depth and mechanization and more stringent health regulations would generally dictate that more air volume is required in order to provide good working conditions underground. However, any increase in the mine’s intake airflow can produce a disproportionate increase in power consumption and hence operating costs due to the cubic relationship between the sup-plied air power and the airflow (Power a Flow3). Furthermore, forecasts of significant increase in energy prices and new commitments with regard to reductions of greenhouse gas(GHG) emissions, determined the mining industry to look into developing new concepts, design tools and incorporate the latest mining technologies in order to lower capital and operating costs while meeting commitments regarding GHG emissions. The advances in computing power and modelling software now make it possible to design, model and schedule a mine from opening to closure. A developing trend is to design and plan the mine by means of orebody modelling software, followed by using discrete-event simulation techniques to predict production rates and evaluate various operating scenarios throughout the life of the mine. The authors are currently evaluating how such process simulators could be adapted in order to forecast the need for materials or a specific resource, and one of these would be the mine’s “life-cycle” airflow demand as a function of scheduled production rates and mine operating characteristics. Further to this, based upon the mine’s life-cycle airflow demand schedule, the ventilation system could then be designed using a mine ventilation simulator. This new design approach would integrate in parallel the development of the ventilation system with the current mining conditions, therefore, heading towards “develop-as-you-go” as opposed to developing the system for final requirements with high upfront costs. This new ventilation system design criteria would also incorporate the use of the “ventilation-on-demand” technology, which will further lower development and production costs and implicitly, the mines’ GHG emissions.

Jan 1, 2004