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By Angelina Anani, Nathalie Risso, Carlos Olmos de Aguilera

The traditional approach to safety clearance monitoring and proper PPE usage in underground mines is time-consuming, costly, and susceptible to negligence. However, automated real-time monitoring can be implemented using computer vision-based approaches. This study aims to develop a system that provides timely information based on the automatic detection of proper PPE use and safety clearance in underground mines. Deep learning and a decentralized computing structure between the cloud and sensing devices (fog technology) are used. We hypothesize that a camera-based system can provide near real-time assessment of proper PPE use and verified clearance to access restricted areas in underground mines.

Jun 25, 2023

Machine breakdowns and maintenance delays are large contributors to lost production and increased operating costs in the mining industry. The U.S. Bureau of Mines is investigating the applications of expert system technology to diagnostic and predictive maintenance tor mining equipment. This will help increase mining productivity and decrease operating costs, by reducing the frequency of equipment failures and repair times. The Bureau has begun this effort by applying expert system techniques to the diagnosis of hydraulic system problems on a continuous mining machine. This paper discusses the development of the hydraulic diagnostic expert system.

Jan 1, 1990

By H. Kiyama

In order to further elucidate the mechanisms involved in autogenous grinding, the fracture of rock specimens in free-fall impact was studied using the theory of elasticity. Stress distributions in rock specimens under various conditions of impact were analyzed and the conditions for failure were examined in relation to the compressive and tensile strength of rock. The energy equation derived for autogenous grinding coincides basically with Lewis' generalized formula or Oka and Majima's formula, and it is sufficiently general to incorporate all of the three older theories, viz; those of Rittinger, Bond and Kick.

Jan 1, 1972

By Jozef S. Stachulak, Bruce R. Conard

INTRODUCTION The concern of occupational exposure to diesel exhaust pollutants is an important workplace issue for the mining industry. During the last three decades of diesel operations at Inco, a significant amount of research and improvement has been made in the area of work environment, and effective diesel operation. This paper will review the experience gained by Inco's Ontario Division from the implementation and the use of modern engines, improved fuel quality, and the exhaust control technology, coupled with adherence to proper maintenance and ventilation design and practices. Past monitoring practices and the current occupational monitoring program at lnco are outlined. A major new research initiative involving multi-stake holders in diesel performance is described. MINING IN THE SUDBURY AREA The discovery of nickel-copper ore in the Sudbury area dates back to the year 1856. The existence of this orebody was noticed when a strong compass deflection was observed by a provincial surveyor. This discovery, even though documented in official re- ports, failed to arouse any public attention at that time. In 1884, a rock-cut was blasted through a small hill near the village of Sudbury to permit laying track for the Canadian Pacific Railway (Boldt 1967). The rock-cut uncovered a body of massive sulfides with a copper content of over nine percent. The mineralization is concentrated along the outer margin of the Sudbury Basin, an oval-shaped structure having a dimension of 55 x 95 kilometres. The ore extends down-dip to to at least 3000 metres below the surface. The mining methods at lnco can be divided into two categories: "filled-stope" and 'bulk" mining. This division, in the broad sense, may also reflect the environmental conditions of the mine. In the past, the selection of a mining method was based on the size, shape, grade and the strength of the ore and its surroundings. The recent development of improved technology and mining equipment permitted wider application of low cost bulk mining methods. UNDERGROUND DIESEL EQUIPMENT The first diesel-powered machine, a 145-horsepower scooptram, was put into operation in March 1966, in a cut-and-fill stoping complex at Frood Mine. The number of diesel machines underground in the Inco, Ontario Division, mines was increased to 360 units by 1971,550 in 1977 (Rutherford 1978), and over 830 diesel-powered units in 1995. The following list indicates current mobile diesel equipment. LHD 194 Loaders 81 Trucks 28 Jumbo Drills 78 Personnel Carrier 101 Service Equipment 155 Locomotives 50 Bolters 30 Scissor Lift 113 About 20 percent of the LHD and truck units are equipped with electronic fuel controlled engines. COMPOSITION OF DIESEL EXHAUST Diesel exhaust contains hundreds of pollutants (Watts 19921, including components of unburned fuel and lubricating oil and products of incomplete combustion of the fuel and oil. These pollutants are emitted either as gases or as particles. Gaseous pollutants include carbon monoxide, nitrogen oxides, and sulfur ox- ides, as well as a variety of organic compounds, such as hydro- carbons, aldehydes, and polynuclear aromatic hydrocarbons. The particle phase, also known as diesel particulate matter (DPM), is the filterable portion of diesel exhaust. Figure 1 depicts the trimodal particle size distribution that arises from different mechanisms of aerosol generation (Cantrell and Rubow 1992). Primary combustion aerosols, including diesel exhaust aerosol, are formed as very small particles (in the 0.001 to 0.08 micrometre range), but physical mechanisms such as condensation and coagulation quickly transfer the aerosol mass from the nuclei mode to the accumulation mode. These processes result in a mass median diameter of approximately 0.2 micrometres for diesel particulate matter, and 90% of the particles are less than 1.0 micrometre in size. These particles have a high surface area, permitting the adsorption of different substances produced during combustion. Mechanically generated aerosols, on the other hand, typically contain particles greater than 1 micrometre in diameter. The particle phases of diesel exhaust contain three components (Bagley, et al, 1996) shown by Figure 2, namely: a carbon- aceous fraction composed mainly of solid-carbon particles, a sulfate fraction containing small hydrated sulfate particles, and a soluble fraction that contains compounds that are soluble in organic solvents and are adsorbed or condensed onto carbon core particles. These compounds consist primarily of higher molecular weight hydrocarbons and PAH's and may contribute 15% to 45% of the weight of the total particulate matter (Schuetzle, 1983). The control of these pollutants is necessary to ensure a healthy work environment. Proper engine maintenance, engine design modifications, improved fuel quality, and use of exhaust control technology, coupled with good ventilation practices, all

Jan 1, 1997

By Shu Fan Chau, Innes Duncan, Harry Asche, Bill Newns

The North Auckland Line (NAL) in Northland, New Zealand, is being upgraded to pass Hi-Cube containers. The line includes many tunnels and bridges which need to be refurbished to improve structural clearances and line capacity. Tunnel 2 along the line, the Makarau Tunnel, has posed special challenges. Opened in 1898, the tunnel suffered multiple collapses during construction and has shown significant distortion during operation. The tunnel has been repaired many times since opening. Successfully enlarging this delicate and distressed structure has involved historical research, advanced analysis and design, and careful construction. The results provide lessons for dealing with brick lined tunnels and poor ground conditions

Jun 13, 2021

By L. Alan Weakly

The U.S. Department of Energy (DOE) has entered into a $l.5 million Cooperative Agreement with Alpine Equipment Corporation/Astro International Corporation ("Alpine") of State College, Pennsylvania, for the evaluation of water-jet-assisted (WJA) mechanical cutting of oil shale under actual mining conditions. A commercial-sized, heavy WJA mechanical miner is being assembled based upon the successful "factory testing" of a smaller prototype miner utilizing standard tungsten-carbide and Polycrystalline Diamond Composite (POC) bits in large oil shale boulders. Actual field testing of the machine will be conducted in an oil shale mine located in the Piceance Basin of Western Colorado. In-mine logistical support is being provided by several oil shale companies through the Colorado Mining Association (CMA) and the U.S. Bureau of Mines (USBM).

Jan 1, 1990

This paper presents the results of an experimental study undertaken to demonstrate the feasibility of using silica sand as a grinding media in stirred ball mills for ultra-fine coal grinding. Laboratory batch as well as bench scale continuous tests indicate that the use of silica sand can reduce the energy consumption by 50% and more over its steel media counter-part. Moreover, this approach has been found to eliminate the disadvantages observed with grinding using steel media such as high replacement cost, contamination of coal through media wear, greater degree of coal oxidation due to higher slurry temperature and greater level of noise dissipation. Additionally, coal-sand attrition system reduces the manpower time required which is often spent towards cleaning and storing of steel media in inert atmosphere to avoid rust and corrosion problems.

Jan 1, 1991

By C. F. Giermak

Over a considerable period of time great interest has been shown in selective dry concentration of fine ferromagnetic particles, although it is only recently that new permanent magnetic materials have been made available to permit building of such permanent magnetic separators. It is well known that the conventional drum separator does' not efficiently separate fine materials. The centrifugal force on any drum acts in accordance with the particle size and gravity, which may beat varying magnitude-.opposite to the magnetic force, especially when the material is not closely sized. The Magnetic-Mechanical Separator (MMS) is designed for the concentration of fine, unsized magnetic materials where the percentage composition of magnetics to nonmagnetics, or the nature and texture of the materials, is such that its unique agitation and shake-out action with no centrifugal force provides greater efficiency than is obtainable by conventional magnetic separation equipment. This machine consists of a complete double belt conveyor unit with a premagnetizing Axial Pole Agitating Pulley at the feeding end of the lower conveyor belt and a special agitating concentrator magnet above the lower belt of the upper conveyor.

Jan 1, 1965

By C. B. Manula

The Crushed Stone Industry plays an important role in Pennsylvania's mineral economy. During 1965, the total production of crushed and broken stone in the United States reached 780 million tons from which 57 million tons were produced in Pennsylvania (Mineral Industries Surveys, 1966). It is further significant that Pennsylvania is the nation's leading crushed stone producer. Future trends in stone production will quite likely parallel those in the construction industry. Stone and stone products are finding greater and more varied uses each year. Continued record expenditures for structures such as dams, highways and buildings are the prime reasons for this accelerated growth in demand. Completion of the interstate road system and the maintenance of Pennsylvania's already expanded highway system form the essentials for this expanding market.

Jan 1, 1968

By M. J. Gula, S. S. Xue, E. P. Horwitz

A study was conducted to remove iron from sulfate solu¬tions using Eichrom'sDipex®extractant, PP'-di(2-ethylhexyl) methanediphosphonic acid (H2DEH[MDP]). It was found that this extractant can effectively and selectively extract ferric ion from highly acidic solutions. Ninety-nine percent of the iron was extracted from a simulated feed solution in a single stage. The separation factor, Fe/Zn, was 106. More than 90% of the iron in a loaded organic can be recovered in an aqueous solution by reductive stripping. This paper presents the experimental results. A new process for iron removal using Dipex extractant is described and discussed.

Jan 1, 2000

By R. R. Dorfler

The existing regrind circuit at the Climax Operations uses sodium cyanide and Nokes reagent to reject pyrite, copper, and lead minerals. Laboratory flotation studies were performed using feed to flotation following first-stage regrinding. The effects of conditioning time, pH, and the concentration of depressants such as Nokes reagent and sodium cyanide on the rejection of pyrite, lead, and copper minerals were investigated. The metallurgical results indicate that, in the presence of depressants, the rejection of copper is strongly dependent on the pH. Preliminary mill testing confirmed the finding. The rejection of impurities is also dependent on conditioning time. The recovery of molybdenite is independent of the variables investigated.

Jan 1, 1981

By Ashma Singh, Nichole Maistry

Due to declining iron ore grades, low-grade ores with complex mineralogy — namely, banded iron formation (BIF) — are being explored to maximize iron ore resources and increase the life of mine. Flotation is the standard global process used for the beneficiation of BIF ores, as it is a complex ore reserve, and liberation is typically achieved below 1 mm. This study focuses on the flotation of a South African BIF, evaluating its response to different collectors, as well as effect of grind. As flotation is an expensive process and South Africa ranks high on the production cost curve, preconcentration by gravity or magnetic separation is performed prior to flotation. Thus, flotation was also performed on a gravity concentrate to determine if a grade suitable for steelmaking (approximately 63 percent) is achievable. The results indicate that the use of an alkyl ether amine-based collector partially neutralized with acetic acid is suitable for separation of hematite from illite and quartz at high pH values. Further optimization tests are being pursued to improve overall recovery and grade.

May 1, 2025

By D. A. Baker, E. A. Gyawu, K. Awuah-Offei

Several underground coal mining disasters, such as Upper Big Branch in 2010, have revealed technological and organizational shortcomings related to self-escape. Efforts to address these gaps have primarily been top-down, that is, identified and implemented by upper management or external governing bodies. In contrast, this study employs a novel miner-centered approach to identify perceived technological boundaries to self-escape. Using a semi-structured, scenario-based survey, we elicit direct feedback from miners about current, emerging, and hypothetical technologies aimed at improving self-escape during mine emergencies. The results show a general high usefulness rating across all 21 technologies in the survey. Miners who work underground (both outby and working face miners) appear to give higher usefulness ratings overall than miners on the surface and other locations. This work will be directly applied to a series of proof of concept and prototype studies on self-contained self-rescuers (SCSRs), refuge alternatives (RA), and communication devises aimed at improving self-escape technologies through miner-centered research and design.

Mar 2, 2022

By J. J. Knoerzer

The scheduled replacement of Inland's A & B coke batteries in Plant No.3 posed some serious problems in terms of pollution control and strained sources for medium volatile coal for a conventional blend. The state-of-the-art of air pollution control during the charging step in the conventional slot-type coke oven has been less than satisfactory. In addition, the work done at the Illinois Geological Survey showed that by preheating the coal blend prior to charging a greater percentage of Illinois coal could be used to produce a high quality metallurgical coke. To assist The Management in the- decision on A & B replacement, Inland Steel conducted a full-scale test program on coal preheating and pipeline charging utilizing the Coaltek system installed on No. 2 battery of the Semet-Solvay Division of Allied Chemical Corporation. The basic objectives of the test program at Semet-Solvay were as follows: 1. Determine the feasibility of producing high grade metallurgical coke from preheated blends containing more than 60% Illinois No. 6 coal. 2. Confirm the performance characteristics in one of the Inland blast furnaces of the coke produced with 75% Illinois coal in the blend. 3. Verify several claims by Coaltek such as: a) Pipelining the hot coal presents no difficulties while essentially eliminates the air pollution problems associated with the conventional charging system. b) Preheating of the coal blend permits the use of higher percentages of high volatile, marginally coking coals (such as Illinois No. 6) in the blend as compared to wet charging.

Jan 1, 1973

By Zhiyuan Ma, Yong Liu, Xianjin Lyu, Jianfang Lyu, Jikui Zhou

A stable and continuous leaching process for niobium and tantalum extraction from ferrocolumbium tantalum (FT) was developed. The effects of initial concentration of HF and H2SO4, grinding fineness, leaching time, and temperature on the leaching rate of Ta, Nb, Fe, and Si were studied. Experimental results show that the leaching rates of Ta, Nb, Fe, and Si were enhanced by the increase of acid concentrate, fineness, leaching time, and leaching temperature. The optimum process conditions are HF initial concentration of 5 mol/L, H2SO4 initial concentration of 2.5 mol/L, − 74 μm percentage of 65%, leaching time of 20 min, and leaching temperature of 25 °C. Continuous leaching of FT was carried out by feeding ore and acid every 20 min. By leaching with HF − H2SO4 for 4 h, then adding appropriate amount of HNO3 into the solution and keeping for another 1 h, a high Nb extraction rate of 99.8% was achieved. The established method provides a promising technique for the high-efficiency separation of niobium and tantalum from FT.

Jun 5, 2022

By Brian V. Roulston

Potash is Canada's leading industrial mineral in terms of value of production, with 11.1 M tonnes of muriate of potash produced in 1992 for a value in excess of $1 billion U.S. Each tonne of potash produced generates about 2 tonnes of waste salt, together with slimes and brine. The disposal of these waste products, particularly the salt and slimes which are discharged on the surface, has recently become an environmental concern. This concern is forcing companies and regulatory authorities to review disposal practices. In New Brunswick, on Canada's east coast, Potash Company of America operates a mine at which 2 M tonnes of potash ore and 0.5 M tonnes of rock salt are mined each year. The mine is situated in an environmentally sensitive area, noted for its dairy farming and salmon angling. In such an area it was recognized that the storage of waste on surface would be unacceptable, and the mine was designed around this principle. Three main waste streams - salt, slimes, and brine - must be managed as an integral part of the mining system. Around 1.5 M tonnes of fine salt tailings from the milling process and the rock salt screening operation, are sent directly to the active cut-and-fill potash stopes to be used as backfill. Slimes and excess brine from the mill are piped underground as a slurry to be discharged into one of the basin shaped stopes created by mining of the rock salt. While the slimes settle out, the clarified brine is withdrawn from part of the stope to be pumped to surface as a feedstock for the evaporator - a process which recovers the contained potash values in the brine. By designing a system which integrates the mining, processing and disposal of all product streams, and by careful production planning, it has been shown that zero effluent potash mining is possible and points the way for the industry in the future.

Jan 1, 1995

By CK Tsang, Jack Muir, Dharman Gersch, Joshua Barry

Correct face pressure is critical to safe operation of a closed face TBM. If inadequate face pressure is applied, this will lead to excessive ground movement, and may result in collapse of the tunnel face. Face pressure calculations are performed manually every few meters along the tunnel alignment. With the application of a 3D ground model, ground profile information can be extracted for automatic computation. This will significantly improve the efficiency and accuracy and is adaptable to changes in design parameters. This paper will discuss the development of automatic computation techniques in extracting information from a 3D ground model.

Jun 13, 2021

By R. E. Scheffel

In February, 1976, Ranchers Exploration and Development Corporation obtained an option from Foote Minerals, Inc., to evaluate reprocessing of two uranium tailing piles. Foote received ownership of the Naturita and Durango tailing piles in 1967 through the purchase of Vanadium Corporation of America. The option was exercised in November, 1976, after initial testwork proved that a viable extraction technique existed. Preparation for production at Naturita began immediately with engineering and en¬vironmental permitting proceeding simultaneously. Production began in December, 1977, just 22 months after acquisition of the property and-was completed 17 months later.

Jan 1, 1981

By Francesco Chiappalone, Tanner Murt, Lance Waddell, Cristina Oñate Salazar

The 3RPORT project is a 5-mile-long, 16-foot-internal-diameter tunnel excavated in hard rock by Slurry TBM in Fort Wayne, Indiana. Two-component grouting can be separated into two core areas of operation: batching and underground operations. This paper addresses the challenges faced and solutions implemented in these fundamental areas. The effects of external factors and their impacts on mix design and batching of grout will be explored. Underground, challenges of monitoring parameters and ensuring a proper mix between the two-components will be discussed, focusing on the adopted technical solutions and considerations to be taken in the design stage of tailskin grout ports.

Jun 13, 2021

By Robert E. Baker

Cortez Gold Mines, the United States' third largest primary producer of gold, commenced continuous operations on January 10, 1969. The decision to proceed to production was made in March of 1968 and construction of the mill and stripping operations for the pit began in April and July, respectively. Anomalous conditions on the slope of Mt. Tenabo along the Roberts Mountain thrust fault zone were discovered by the U.S.G.S. while conducting geochemical surveys in the old Cortez silver district. Following the discovery of gold an intensive program of drilling was organized. Drilling outlined an orebody with 3.5 million tons of ore averaging 0.28 ounces of gold per ton. It was on the basis of this reserve that a 1700 t. p.d. cyanide plant was designed. Needless to say, with such a limited ore reserve, economies in design and construction would have to be observed. Cortez Gold Mines is a joint venture with American Exploration & Mining Co., The Bunker Hill Company, Vernon F. Taylor, Jr., and Webb Resources, Inc. , as partners. American Exploration & Mining Co. is the operating partner.

Jan 1, 1969