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The relative abundance of coal in India compared to other fossil fuels makes it a natural choice as the primary source of fuel, be it for steel making, power generation or for other uses. The wide variations in nature and type of Indian coals formed during lower Gondawana period and categorized as difficult-to-wash due to its typical mineral matter association with the organic matrix call for suitable beneficiation techniques as the preferred option for quality upgradation. The good quality coking coals of the upper seams are fast depleting leaving behind the inferior quality lower seam coal. The lower seam coals presently being mined are mostly low volatile coking coal (LVC). They constitute about 50% of the total coking coal reserves in India. The beneficiation of Low Volatile Coking coals pose a major challenge and detailed R & D studies was taken up to study the beneficiation characteristics of these coals. The studies revealed that the liberation characteristics at coarser sizes are very poor and the coal is to be ground to finer sizes for liberation. The most important factor that determines coal cleaning efficiency is liberation of organic matter from mineral matter. To achieve liberation grinding is necessary as a result range amount of ultra fines (-0.063 mm) coal is generated. Presence of these large amount of ultrafine in the coal fines, often impose severe technical constraints affecting not only its floatability but also in the downstream treatment of the products like dewatering and cake formation particularly when it is beneficiating through froth flotation. In the present paper optimization of ultra fines (-0.063 mm) has been tried for a LVC coal of Jharia coal field for the better liberation and beneficiation of the above coal fines. It is observed that by optimized, combination of size and number of balls generation of fines can be controlled with liberation. Keywords: coking coal, liberation, floatability, dewatering

Sep 1, 2012

By D. Harrington

This circular presents part I of a review of the literature on effects of breathing dusts, with special reference to silicosis, largely in the minim; and allied industries. The literature on this subject is so extensive that no attempt has been made to include all published material but only to assemble some of the more outstanding data on several aspects of the subject. Parts II and III will deal with prevention and treatment of dust diseases and some of the economic and legal aspects of dust diseases in industry, with special reference to mining. Dust diseases arc much before the public at present, and there is good reason to believe that the information on the subject available to the layman is extremely meager; even those rated as experts usually have a more or less theoretical conception of the diseases, their causation, remedies, and prevention, rather than actual experience with them. Until recently little attention has been given to prevention, and the usual attitude of the engineer, upon whom the main reliance for prevention ultimately must devolve, has been to let "sleeping dogs lie" or, more definitely, to "let well enough alone." However, the "laissez faire" attitude no longer is tenable, and in the past few years numerous conditions have caused those engaged in industry, including mining, to bring the subject before the public with a view to ascertaining the facts upon which to formulate remedial measures, primarily preventive.

Jan 1, 1935

[CONTENTS COUNTY NO. OF MINES MINE INDEX PAGE]

Jan 1, 1980

By J. W. Spyker, D. H. Filson, W. H. W. Husband

"Large deposits of sodium sulphate exist in southern Saskatchewan in the brines or muddy crystal beds of alkali Jakes. Currently, more than 300,000 tons per year of sodium sulphate are produced from these lakes and sold as salt cake to the paper industry. Most of the production is obtained from the brines of a limited number of Jakes.The Saskatchewan Research Council was requested to develop a process for recovering sodium sulphate from the muddy crystal beds so that this type of deposit could be exploited in the future. A flowsheet was developed with the aid of phase diagram data and the process was studied on a pilot-plant scale using raw material from three different lakes. Satisfactory yields and product purities were obtained in all cases, and an economic analysis indicated that a 100,000-ton-per-year sodium sulphate plant could produce salt cake at a cost of $12.26 per ton for a rate of return upon investment of 16 per cent at current market prices."

Jan 1, 1966

By Bertrand L. Johnson

As potash is more necessary to the agricultural economy of the United States now than ever before it is gratifying to find that the virtual stoppage of imports from Germany in late 1939 caused none of the anxious foreboding that gripped American farmers in 1914. For long decades this country, in common with tie rest of the world, depended upon German potash, but today our expanded needs can be mot from domestic sources. The present armed conflict in Europe, like that of 1914, disrupted a world monopoly, but the cartel that in recent years controlled 90 percent of the world output (see fig, 1) was an international syndicate comprising French, Polish, and Spanish as well as German producers and having reported sales agreements covering production in the U. S. S. R. and Palestine. The break-up of these commercial agreements has necessitated readjustments but generates no such alarm as the closing of a single source of supply. In striking contrast to the critical shortage that developed a quarter century ago, no increase in prices has occurred or is anticipated in the domestic market.

Jan 1, 1940

By Jr. Schnakenberg

The automation (robotization) of coal mining activities at the face offers improvements in worker safety and productivity. The evolutionary introduction of autonomous, intelligent robotic machines to perform the most hazardous tasks may become a reality within the next 10 years. The U.S. Bureau of Mines Robotics and Automation research program is aggressively pursuing the development of the enabling technology necessary to achieve this goal. This program consists of both core and applications research, each focused on the fundamental issues of robotic technology. In the short term, the research is directed specifically to the robotization of present-day underground equipment and is being performed in a manner that can make incremental improvements in safety and productivity. The long-term goal is the development of intelligent autonomous mining systems.

Jan 1, 1990

By D J. Brake

There are many sources of gas in underground mines including development and production blasting, strata gases, spontaneous combustion, diesel equipment, chemicals used for a wide range of functions, welding activities and fires.It is only in relatively recent times that electronic gas monitors (or detectors) have become both safe and affordable for routine use.In modern mines, gas monitors should be in daily use by the ventilation department as well as blasting re-entry (or clearance) crews, and are often used by drilling crews, shift supervisors, hygienists and mine rescue or fire fighting crews.When first released, electronic gas monitors needed to be sent off-site periodically for calibration at a suitable accredited laboratory. Between calibrations, their accuracy was unknown. More recently, ‘bump testing’ and field calibration has become possible on the mine site, improving both reliability and safety as well as reducing the total number of gas monitors that need to be in use.There has been almost an overwhelming increase in the number and sophistication of gas monitor features in recent years. This paper reports on a case study into the key criteria that ventilation practitioners should be aware of with respect to the specification and selection of the most recent gas monitoring systems, and recommends good practice for site-based operation and calibration.CITATION:Brake, D J, 2015. Specification and selection of hand-held gas monitors (detectors) for underground mines, in Proceedings The Australian Mine Ventilation Conference, pp 143–154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By David J. Forrester

"CANMET’s research into underground coal mining is primarily conducted at the Cape Breton Coal Research Laboratory (CBCRL), established in 1981 to conduct safety research in underground coal mines. Located close to Canada’s largest underground coal producer, in the Sydney Coalfield of Nova Scotia, CBCRL’s program also includes the two western underground coal operations. CBCRL is a relatively small laboratory with a staff of thirteen — eight professionals and five support staff — with an annual budget of over $1 million. In order to maintain effective research response, flexibility is key and staff are increasingly working in project teams, crossing traditional section ties and also drawing from specialist expertise elsewhere within CANMET.CBCRL’s research activities have had a substantial impact on the Canadian underground coal mining industry, particularly in Cape Breton. CBCRL contributed to Cape Breton Development Corporation’s (CBDC’s) threefold reduction in lost-time accidents in the 1980s. Also, in the last four years alone, CBCRL’s work has enabled CBDC to save over $17 million in improved utilisation of reserves and cost savings. The work embraces the three traditional areas of mine environment, strata mechanics and mining technologies, however the current direction has been strongly influenced by recent external and internal factors. It is timely to review progress and recent directions."

Jan 1, 1996

By Frances H. Clark

IN wartime, the fabrication and use of metals assumes increased importance, for a modern war of sizable proportions cannot be undertaken with- out a vast supply of this material. Light alloys of aluminum and magnesium, which were comparatively unknown in the last war, will play an important role in this one. Due to research on a vast scale in the interim of years, industry is today well equipped to fabricate metals on an enormous scale. Research for the past year has been most productive and a comprehensive survey in the space of this article would be impossible. It is hoped that the stressing of a few items here and there out of a great quantity of able work will indicate in a small way the advances made within recent times. Specific references to the literature will be omitted at the Editor's re- quest but some authors of papers that I have found of special interest are mentioned.

Jan 1, 1940

By G. V. Campbell, O. T. Holdsworth, M. G. Nelson

A senior design project is required by all accredited mining engineering degree programs. Often referred to as the capstone of a student’s education, this project is expected to include all the important components of the preliminary economic assessment of a mineral prospect, including orebody modeling, grade and reserve estimation, selection of mining and processing methods, preliminary mine design, access and utilities, environmental compliance and reclamation, and financial analysis. Two of the authors (Campbell and Holdsworth) completed a senior project in 2021. They analyzed the Akie zinc deposit located in Canada. This paper summarizes the economic analysis portion of that project. The two primary objectives of this economic analysis were risk reduction and integration of economics and engineering. Addressing risk is important as risk is one of the primary concerns in mining investments. Risk reduction was the primary concern through the entirety of this economic analysis. Integration of financial analysis and engineering design was the first component of a risk reduction design. This allowed for financial and engineering design to be optimized in conjunction with one another. This produced benefits from both a financial and an engineering prospective. From a market, economic, and financial risk perspective, risk was reduced by forecasting multiple metal price scenarios, and then addressing the Akie project’s economic viability at each price point. Lastly, risk was address through consideration of nontraditional financing options. The project also sought to minimize financial and human capital risk, by proposing mutually beneficial cooperative social relationships and favorable work, schedules. Description of that work is not included in this paper.

Mar 2, 2022

Remarks of Mr. Robert W. Hunt, General, Superintendent, Albany and Rensselaer Iron and Steel Company., Troy N. Y.—In discussing Dr. Dudley's two most interesting papers, I feel a natural hesitancy in disagreeing with conclusions formed after such careful and conscientious work. But I think he has made his deductions from too meagre premises. The analyses of but twenty-five samples are entirely too few to justify the establishment of so important a formula. When we consider that he indirectly proposes to regulate an interest amounting, even at the present low prices, to over $20,000,000 per annum, we may well hesitate before accepting a formula based upon the chemical and physical analyses of but twenty-five steel rails. Dr. Dudley touches the keynote in referring to the proposed labors of the Government Test Commission. They based their hopes of attaining success upon the chemical and physical analyses of a very large number of samples, and in the only branch of investigation which the short-sighted policy of Congress has allowed them to complete, i.e., chain cables, we find that a dozen, twenty-five or one hundred tests gave no satisfactory results. It was only after many hundreds that they were enabled to' draw conclusions. There are so many circumstances hearing upon the life of a rail, that the task of extracting a correct result seems herculean. I presume I am right in stating that in our Northern latitudes early winter and spring months witness the breaking of the greatest number of rails, thus seeming to prove that an unstable road-bed has much to answer for. Then, again, broken and flattened wheels must be taken into account, but I am convinced that more rails have been broken by the treatment which they received before leaving the rolling-mill

Jan 1, 1879

By Michael T. Nigbor

This Bureau of Mines publication identifies the significant environmental issues associated with the potential development of strategic and critical minerals in the Stillwater Complex, MT. The Stillwater Complex contains deposits of Cr, platinum-group metals (PGM), and Ni. Issues that must be addressed prior to minerals development include the effects mining, milling, and smelting will have on the land, water, and air, and methods of minimizing the environmental impacts.

Jan 1, 1985

By R. Sellaro

It has long been understood that extended occupational exposures to respirable mine dusts can lead to chronic lung disease. In underground coal mines, coal workers pneumoconiosis (CWP) and silicosis are major concerns. While there have been many studies aimed at understanding total dust concentrations and silica content associated with different mining conditions (e.g., locations/occupations within a mine, cutting methods, geologic strata), little research has been completed to more comprehensively characterize respirable dust (i.e., by distributions of particle composition, size or shape). For such analysis, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) may represent a powerful tool. This article is a preliminary investigation of SEM-EDX to characterize respirable dust from an underground coal mine in Central Appalachia. Samples were collected from various locations in the study mine, and individual dust particles were identified and classified by mineral type. A continuous personal dust monitor was also used to estimate respirable dust concentrations during sampling. This data was compared to particle densities observed under the SEM. Dust is generally defined as small, solid particles with an effective diameter between 1 and 100 µm. In underground coal mines, dust is produced by a variety of activities such as coal and rock cutting, materials handling, haulage and from a variety of materials. While the coal itself is primarily made up of organic carbon, it is estimated that as much as 60 percent of coal mine dust consists of mineral matter, including clays, metal oxides and sulfides, carbonates, quartz, phosphates and heavy minerals (WHO, 1997). Mineral matter may be ingrained in the coal seam or associated with adjacent or interlying strata, and may also be contributed by specific activities such as rock dusting. When dust is generated or made airborne, suspended particles tend to settle slowly with gravitational forces, but can remain airborne for extended periods of time depending on environmental conditions such as air velocity (Courtney et al., 1986) and particle properties such as size (ISO, 1995; WHO, 1999). Thus, miners working underground are routinely subject to occupational dust exposures ? with highly variable characteristics between and even within mines.

By G. Eaton

Safety management is an important mortal and business function in construction. Contractors have traditionally tracked and reported lagging indicators, e.g. fatalities and lost-time accident rates, to measure their safety performance and stay in compliance with relevant regulations. Over the last several decades, contractors became more proactive in their approach to safety and developed programs that track leading indicators, e.g. safety audits and safety climate. In particular, safety climate measures workers? perception of safety management and its effectiveness in the workplace. Past literatures indicated that, while some industrial construction contractors ignore safety climate measures, others are limited by a lack of a formal means to measure safety climate. In this study, a survey approach is used to measure an industrial construction contractor?s safety climate through three key areas: management commitment, job control, and general safety climate. As a pilot study, a total of 214 individuals at a fabrication facility participated in the survey to verify the validity and effectiveness of the proposed survey approach. This survey study also confirms that job control and management commitment have a positive correlation and that worker demographics have an effect on respondents? perceptions of management commitment.

Aug 1, 2013

By S. G. Tsimas, A. K. Moutsatsou, G. K. Parissakis, M. A. Komiotou

For Greek kaolin producers, a considerable proportion of whose output is from deposits containing more than 4 wt% Fe2O3, the colouring resulting from iron oxide impurity represents a serious problem that necessitates upgrading of the ore to meet commercial specifications. Autoclave leaching with oxalic acid for 1 h at 120 degrees C and 5-6 bar was shown to reduce Fe2O3 by up to 90% without affecting the structure of the kaolin, which maintained its physicochemical properties. The iron oxalate product can either be removed from solution or precipitated as iron hydroxide with recycling of the oxalic acid

Aug 1, 1995

By David E. Swanson

The U.S. Bureau of Mines undertook a basic investigation of collimated abrasive water-jet behavior because a more complete understanding of the fundamental process may lead to further technical advances. Laboratory experiments used 2-mm water-jet nozzles and new entrainment apparatus to analyze collimated abrasive water jets operating under varied conditions. Maximum water pressure was 69 MPa to permit use of conventional hoses with a burst-to-operating-pressure ratio of 4. Nozzle and induction line pressures, abrasive induction rates, and jet reactive thrust forces were recorded for each operating condition. Average jet velocity and power were determined from component mass flow rates and reactive thrust force measurements. Relative velocity and cross-sectional distribution of abrasive particles were determined using impact analysis techniques. Other jet characteristics were determined photographically. Properties of free water jets, collimated water jets, and collimated air-water jets were determined for comparison.

Jan 1, 1989

This report discusses the nonfuel critical minerals position of the United States-both current and future (to the year 2000). We have assumed that there will be no major global disturbances-military, political, or economic-during the rest of this century. However, international relationships, strategies, and conditions that affect the supply of minerals are very tenuous, normal trading patterns can be easily upset, and national and ideological objectives can and do interfere with "normal" free market conditions. For example, the Department of Defense has reported that the Soviet Union is engaged in a strategy designed to reduce the availability of strategic minerals, through either physical disruption, market manipulation, or domination of producing or neighboring states. Although such a strategy poses serious concerns for the United States and the free world, the impacts of disruptions are not covered in this publication. Historical Perspective The modern industrial economy of the United States is founded on the production and use of minerals.* Two hundred years ago our forebears began taming a raw continent, developing a base for agriculture and a rudimentary minerals producing system. In the 19th century, with the aid of imported labor and capital, the development of America's vast natural resources was undertaken, and the transition from an agricultural to industrial society was underway. By the century's close, the United States had emerged as a great industrial power, partly through the development of such mineral resources as iron in Minnesota and coal in Pennsylvania.

Jan 1, 1983

By Nilabjendu Ghosh, Satyendra Kumar Singh, Gautam Banerjee, Harshit Agrawal

High-production methods like longwall mining with hydraulic powered supports are necessary to increase underground coal production in India. Longwall mining had a mixed success record for Indian geo-mining conditions. In this paper, an analysis is presented to optimally design an array of chain pillars in multi-seam longwall mining panels in the deepest coal mine in India. The study found that a chain pillar of 80-m width and 195-m length is necessary for long-term stability without any reinforcement. It was also observed that an optimum chain pillar can be designed by providing suitable side reinforcement (side bolting) which will reduce the chain pillar dimensions to 55-m width and 160-m length. Optimum design of chain pillars will reduce the coal locked up in these chain pillars by ~ 77%. This will also reduce the gestation period of longwall mining panel development. This paper also evaluates the maximum tensile subsidence strain induced at the surface and finds that the values are within the safe working limit of 3 mm/m. Thus, this paper finds direct application in the design of future multi-seam retreating longwall mining panels in Indian geo-mining conditions.

By Nilabjendu Ghosh, Satyendra Kumar Singh, Gautam Banerjee, Harshit Agrawal

High-production methods like longwall mining with hydraulic powered supports are necessary to increase underground coal production in India. Longwall mining had a mixed success record for Indian geo-mining conditions. In this paper, an analysis is presented to optimally design an array of chain pillars in multi-seam longwall mining panels in the deepest coal mine in India. The study found that a chain pillar of 80-m width and 195-m length is necessary for long-term stability without any reinforcement. It was also observed that an optimum chain pillar can be designed by providing suitable side reinforcement (side bolting) which will reduce the chain pillar dimensions to 55-m width and 160-m length. Optimum design of chain pillars will reduce the coal locked up in these chain pillars by ~ 77%. This will also reduce the gestation period of longwall mining panel development. This paper also evaluates the maximum tensile subsidence strain induced at the surface and finds that the values are within the safe working limit of 3 mm/m. Thus, this paper finds direct application in the design of future multi-seam retreating longwall mining panels in Indian geo-mining conditions.

By Tyler Luxner

Stillwater Mining Co. (SMC) is the largest primary producer of platinum and palladium in North America. SMC operates two underground mines in south central Montana, along the 45-km (28-mile) platinum/palladium J-M Reef in the Stillwater Complex. The Stillwater Mine exploits 9.6 km (6 miles) of deposit strike length and East Boulder Mine exploits 4 km (2.5 miles) of deposit length. The two mines are 20.4 km (12.7 miles) apart with SMC controlling a considerable length along the entire J-M Reef trace. Production at the Stillwater Mine began in 1986 and in 1988 the first tunnel boring machine (TBM) was commissioned, becoming an integral part of mine development at SMC. TBMs have been used for developing production footwall laterals (FWL) to access new mining blocks at the Stillwater Mine, as well as boring twin crosscut ac-cess tunnels at the East Boulder. Two TBM development expansion projects are currently in progress: the Graham Creek project at the East Boulder Mine, which will extend footwall lateral development 2,591 m (8,500 ft) to the west, and the Blitz project, where a TBM will be commissioned to extend east out of the Stillwater Mine to 3,658 m (12,000 ft) beyond the current production mining front. General strike and dip of the Reef is west to east and to the north, respectively.

Jan 1, 2012