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By J Johansson, B Johansson

The mining industry needs to attract and recruit young talented people. An important task is, therefore, to create an attractive mining workplace that engages with, and motivates youngsters who are not particularly interested in working in the industry. This paper aims to illustrate a way forward for the mining industry to form healthy and safe workplaces honouring key components such as knowledge, skill, co-operation, continual development and acceptance of diversity. This is a way to create a vision of healthy and safe mining work. The mining industry must work towards zero vision; a future without accidents and hazardous environments. In this paper the authors discuss different aspects of an ‘attractive workplace’ and summarises lessons learnt in 26 statements dealing with safety, both physical and social work environments, and social responsibility. The authors hope these recommendations will provide some guidance for how attractive workplaces should be designed for future deep mining.The paper is based on lessons from two large European projects, a Swedish-Polish project: The Smart Mine of the Future; and a European Union project: Sustainable Intelligent Mining Systems (SIMS). One of the authors was the WP leader of health and safety in both projects.CITATION:Johansson, J and Johansson, B, 2017. Attractive workplaces in future underground mining, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 99–102 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By B Shi, Y Li, L Ma, F Zhou

Subsurface fires are a common threat to coal mining, as spontaneous combustion of coal can potentially result in gas combustion and explosion. Fire-proof techniques, such as grouting, foam, or colloid injection, are not in a position to function ideally, due to the limited coverage and stopping the extinguishment substance from reaching the fire location. Liquid nitrogen, as a kind of all-submerged fire prevention or extinguishing method, can rapidly extinguish fires, thus preventing gas explosion and minimising extinguishment time. Injecting liquid nitrogen through boreholes is an important way during the period of mine catastrophe. But liquid nitrogen is not effective enough in infusion; technical issues restrict the development and utilisation of liquid nitrogen fire prevention and extinguishing technology. Immediate infusion of liquid nitrogen is usually associated with ‘air slug’ (the balloons and bubbles in the pipeline which hinder the flow of low-temperature liquid), which blocks pipelines for liquid nitrogen injecting. Another issue is that the pipeline tends to be damaged due to freezing, which undermines the injecting efficiency of liquid nitrogen and its application result. In order to solve the problems of the low efficiency and some other related field issues in liquid nitrogen perfusion, the ground–underground high efficiency liquid nitrogen injection technology were developed. Implementation of liquid nitrogen infusion techniques in Chinese coalmines achieved the goals of fire prevention and air-cooling. The technique presented in this paper is efficient in absorbing heat, and consequently, displacing oxygen and combustible gases. Field tests at Rujigou and Yangchangwan Coalmine justified the efficiency of the technique. By using this technique, there was no waste left behind, which may impede the subsequent production. The presented technique is of great benefit to the social, economic, and environmental aspects of mining operations, and will have broad applications in fire prevention for large-scale coalmines.CITATION:Zhou, F, Shi, B, Li, Y and Ma, L, 2015. Key techniques and engineering applications of stereoscopic liquid nitrogen infusion for coalmine fire prevention, in Proceedings The Australian Mine Ventilation Conference, pp 291–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By T. R. Wright

THE Corporation operates concentrators in four camps: Casapalca. Morococha, Cerro de Pa-co, and Mahr. The present concentrator at Cerro de Pasco is the newest having been completed in 1943. and that at Casapalca the oldest, having been built originally as a gravity concentrator, in 1889. Prior to 1925 the Corporation's milling operations were confined to the beneficiation of silver-bearing copper ores, and treatment of these ore: by flotation was started in 1918. Although fairly large deposits of complex, fine-grained lead-zinc ores existed, little progress had been made in the treatment of such ores--in Peru or elsewhere-until the early 'twentics. The Casapalca concentrator began the selettive concentration of complex leadzinc ores by all-flotation methods in 1925, or contemporaneously with the commercial development of selective lead-zinc flotation in the United State:.

Jan 1, 1945

By Chiranjib Sarkar, Sibapriya Mukherjee, N Kumar Pichumani

With the rapid expansion of urban transportation systems, tunnels and cut & cover structures are considered as the only solution in improving the urban space congestion problem in mass rapid transit system. Therefore, it is necessary to accurately design underground structures with realistic assumptions and considerations of design parameters like site geotechnical data, water table, surcharge load etc. Over conservative approach provides not only uneconomical design but sometimes it also causes overdesign of the concerned structures. Water table depth has a significant role in some design aspects of underground structures like floatation check, lateral and uplift pressure on the buried structure, etc. In current practice of tunnel and cut & cover structure design, water table is assumed to coincide with the ground level. Most of the Design Basis Reports & Outline Design Specifications directly mention consideration of water table at ground level for floatation check and load calculations, etc. However, the actual scenario is different in most of the cities specially in northern, central, western and eastern regions of India except the coastal cities. In the present study an attempt has been made to carry out a parametric study on the effect of water table depth in the design of a typical 6.3m outer diameter circular tunnel with 6m backfill. In this study, it is also attempted to establish an analytical method of calculating the most realistic consideration of water table depth instead of the present hypothetical assumption of considering water table to coincide with the ground level. The findings of the current study may be helpful to the researchers and practising engineers in design of tunnel and cut & cover structure for subways and metros.

Nov 1, 2022

By Zong‑yu Li, Shao‑jian Ma, Xiao‑jing Yang, Jin‑lin Yang, Xing‑nan Huo, Heng‑jun Li

Optimizing and adjusting the particle size composition of grinding products is of great significance for improving economic benefits and resource recovery and utilization. In this study, grinding contribution and quantitative separation of impact and grinding mechanism in cylindrical mill were creatively researched, and the grinding technical efficiency of impact and grinding was coupled to the grinding technical efficiency of grinding in drop-off mode. The results showed that the contribution rate of impact and grinding in grinding in drop-off mode varied with the grinding time. On the whole, the contribution rate of impact action increases with the grinding time and gradually becomes stable, and the contribution rate of grinding effect was just the opposite. Under the experimental conditions, the main contribution of the grinding process is impact action, and the contribution of grinding action is auxiliary. In addition, the contribution rate of impact and grinding effect in grinding in drop-off mode was also related to the feed particle size. The contribution rate of impact effect decreased with the decrease of feed particle size, while the contribution rate of grinding increased inversely.

Aug 3, 2023

By Harold J. Bennett

The Minerals Availability Program is a Bureau of Mines Program to systematically measure and classify identified worldwide nonfuel mineral resources according to their respective extraction technology, economics, and commercial availability. The program is designed to identify, collect, compile, and evaluate information on worldwide active mines as well as on developed and explored mineral deposits, and on mineral processing plants. Objectives are to classify domestic and foreign resources, to identify by cost evaluations resources that are reserves, and to prepare analyses of the availability of these resources for 34 commodities and secondary minerals. Availability analyses consider such factors as geographic location, the type of producible material, the technology and time required to produce a marketable product, and the productive capacity and unit cost for each deposit. These factors, reflected in the aggregated tabular and graphical data in the study for each commodity, are developed for consideration in the formulation of both domestic and foreign mineral policy. To date, the data have been collected for the 34 commodities and the availability analyses are in various stages of completion; expected first cycle completion date for all 34 is early 1986. Raw and aggregated data are available to the public in the form of computer-generated listings, tapes, and maps as well as in published reports. Also, systems developed to assist in performing the engineering and economic c analyses, including the computerized economic evaluation program (MINSIM) and the cost estimating system (CES), are available.

Jan 1, 1984

By Zhuo Sheng

We have designed a high-temperature Raman micro-furnace and cell that is suited for the electrochemical process study of the NO3 − in molten NaNO3– KNO3 (fraction of NaNO3 50 wt%) salt. During the cycle voltammetry and constant potential electrolysis process, the Raman laser beam was focused near the electrode; subsequently, the Raman spectra are obtained and the reduction process of NO3 − is analyzed. In the CV cathodic scan process, the new peak attributed to the ν1 mode of NO2 − emerges, and the peaks assigned to superoxide ions (O2 −) and peroxide ions (O2 2−) are not found. In the constant electrolysis process, the peaks at 1130 and 800 cm−1 appear when the potentials are between −2.0 V and −3.2 V (vs. Pt). The results show that when the NO3 − is reduced in molten the NaNO3–KNO3 mixtures, the reduction product O2− cannot stably exist, and O2− will react with NO3 − to form of superoxide ions (O2 −) and peroxide ions (O2 2−).

By Lynn B. Hales

The Supervisory Computer System at Cities Service copper mine and concentrator at Miami, Arizona was installed at Pinto Valley in the spring of 1975. Design and specification [l] of the digital system was initiated jointly by key plant personnel at Pinto Valley and staff of Cities Service Research and Development Company. The Pinto Valley digital system [2] may be classified as a supervisory control system of hierarchical design. There are three fully independent satellite computers which retrieve and reduce the raw plant data from each of the three main operating areas - the primary crushing plant, the fine crushing plant, and the grinding and flotation plant. While the three satellite computers are core resident systems, the master computer is a disc-based operating system which also interfaces with a computer controlled on-stream x-ray analyzer system. Figure 1 illustrates the basic system configuration [3]. The software systems required to support a large system are quite diverse and vary greatly in function. The philosophy followed in dividing the software into three categories was designed to: 1) fully utilize existing process knowledge of technical staff; 2) delegate certain software tasks to outside sources already skilled and trained in software development; and 3) maintain final control over the design and operation of each system.

Jan 1, 1976

By R. J. Beltrame

The Cuyuna range, located in east-central Minnesota, consists of a sequence of argillite, siltstone, iron-formation, graywacke, slate, and quartzite of early Proterozoic age. Manganese-bearing materials occur within the iron-rich strata of the Trommald Formation and the Rabbit Lake Formation. Computer-assisted resource estimates, based on exploration drill hole information, indicate that the Cuyuna range contains a minimum of 176 million metric tons (Mt) of marginally economic manganiferous rock with an average grade of 10.50 weight percent manganese. The calculated 18.5 Mt of manganese on the Cuyuna range could supply this country's needs for this important and strategic metal for 16 years. An additional resource of 6.9 Mt of manganese metal is available in the lower grade deposits. The majority of these calculated resources are extractable by current surface mining techniques.

Jan 1, 1981

By SANDVIK WHITE

The mining industry produces approximately 4-7% of global greenhouse gas (GHG) emissions. It is fundamental for mining operations to take immediate sustainable action to actively contribute to an emissions-free future for the next generations. The mining industry has traditionally relied heavily on diesel technology and transitioning to more sustainable solutions requires change management to drive cultural acceptance and new product development. Sandvik was interested to find out the lifetime emissions of a single drill rig and to compare similar application diesel and BEV drill rigs with same use profile to each other. That led the calculation and pondering towards comparing different countries and mine sites as well

Jan 1, 2023

By Fangtian Wang

The fully mechanized longwall mining was employed in a shallow coal seam that was under the gobs of room and pillar mining and overlain by thin bedrock and thick loose sands. Operational practices have demonstrated that severe accidents would occur including roof structure instability, roof steps, damages of shield supports, and face bumps triggered by the large area roof weighting, resulting in serious threats to the safety of underground miners and equipment. This paper uses Shigetai Mine, located in the Ordos area, Inner Mongolia, as the study site. It fully considers the geological conditions of 3-1-2 coal seam and employs theoretical analysis, 3DEC numerical simulation, and field measurements to analyze the overlying strata movement for the shallow seams under an abandoned room and pillar mine without pillar extraction. The research results serve as an excellent guide to mining in similar geological and mining conditions.

Jan 1, 2014

By Jerry A. Steding

How many times have you heard "You can't drive piles because of the vibration."? You hear these words come out of the mouths of owners, engineers, and contractors. When a piling contractor hears this, he can almost always do a psychological profile of the individual uttering these words of wisdom. If the owner makes the statement, we know the odds are about 95% that the owner owns the building next door or he wouldn't care what happens to it; or the guy next door has threatened to sue the owner if he even so much as walks across the site of the proposed new building. If the owner owns the building next door to the new construction you can also be just as certain the old structure has undergone settlement. If the statement comes from the mouth of the contractor, it is usually just a case of him being inexperienced.

Jan 1, 1988

By S. Deming

Coal is China's main source of energy. In 1988, 76.1% of commercial energy consumption was supplied by coal. To provide a rational utilization of its coal resources, China has paid considerable attention to coal preparation over the last 10 years. In 1980, there were only 105 washeries treating about 100 million tonnes of coal, but by 1988 there were 151 washeries treating 171 million tonnes per year. This paper describes the development of China's coal preparation industry; its growth, the equipment, and the technology. Statistics and information on the current status of the industry are also be presented.

Jan 1, 1991

By C. E. Shoenfelt

Jan 1, 1942

By C. E. Shoenfelt

Jan 1, 1942

By Zay Jeffries

IT has been known for a number of years that certain aluminum alloys could be hardened by quenching from a temperature of about 500° C. Immediately after quenching the total increase in hardness is not marked, but the hardness increases gradually so that after about 4 days, it has reached a maximum. The actual increase in hardness probably continues for weeks or even months, but in order to detect the differences after 4 days, it is necessary to make tests at rather long intervals. So far as is known to the authors, Alfred Wilm was the first to discover these properties in aluminum alloys.1 The aluminum-copper alloys are amenable to this treatment and the addition of magnesium makes the heat-treatment effect more pronounced. Until recently heat treatment of aluminum alloys has been confined to the worked alloys in the form of sheet or extruded products. The alloy that has been most used in this connection is known commercially as duralumin and has about the following composition: copper not exceeding, 6 per cent.; magnesium not exceeding, 2 per cent.; manganese not exceeding, 1 per cent.; commercial aluminum,2 balance. A typically good alloy in this range consists of: copper, 4 per cent.; magnesium, 0.5 per cent.; manganese, 1 per cent.; commercial aluminum, balance. This alloy can be rolled into sheets or extruded; and in this condition it can be heated in the ordinary furnace atmosphere to a temperature near 500° C. and quenched in water. After about 4 days it will have the following physical properties: tensile strength 55,000 to 60,000 lb. per sq. in. (3866 to 4218 kg. per sq. cm.); elongation in 2 in., 15 to 20 per cent. No harmful effects of the furnace gases or even the air, if the heating is affected in an electric furnace in an air atmosphere,

Jan 9, 1919

By W. J. Putnam, H. F. Moore

THIS paper gives a preliminary summary of results of tests on the resistance to fatigue under reversed stresses of steel subjected to cold-working and of tests to determine the effect of rest on the endurance of steel under reversed stresses. The tests of cold-worked steel were undertaken as part of an investigation by the National Research Council Committee on Fatigue Phenomena of Metals and were made by Mr. Moore; the tests to determine the effect of rest are part of an investigation now being made by Mr. Putnam. Both series of tests were made in the Materials Testing Laboratory of the University of Illinois. The preliminary results of these tests are reported now because it is believed that test data on fatigue strength should be available at the earliest possible moment; however, it should be clearly kept in mind that this paper gives preliminary results and is intended to encourage discussion rather than to give final conclusions. Before giving the data of the tests, the writers will explain the term "fatigue strength" as used in this paper and will discuss briefly the method used in interpreting the test data of repeated-stress tests. " The term fatigue strength, as applied to a material, may be defined as that maximum fiber stress that will cause fracture of the material after the repetition of any given number of cycles of stress, each cycle involving the variation of stress from a minimum to the above maximum. The fatigue strength, then, varies with the number, of repetitions occurr,ing in the lifetime of a structural or machine member and with the range of stress for each cycle of stress. The fatigue strength will be lower for a member in which the stress is completely reversed than for one in which the stress varies from zero to a maximum. In interpreting test data from fatigue tests under reversed stress, the stresses and corresponding numbers of repetitions required for failure are plotted on logarithmic cross-section paper. In 1910, Professor

Jan 1, 1920

By Reinhardt Thiessen

UNDER sulfur in coal, is usually understood that form of sulfur which is combined with iron and known as pyrite. It occurs in the form of halls, lenses, nodules, continuous layers, thin sheets, or flakes, both in horizontal planes and vertical cleavage fissures. But pyrites also occur as very fine microscopic particles, or nodules, disseminated through the compact coal. This form has had but very little consideration. Finally, there is sulfur in coal in an amicroscopic form (not visible with an ordinary microscope), probably combined with the organic matter that exists -in tile coal. This form has had considerable attention from a scientific standpoint, but has probably not been recognized enough on the economic side. One or the other, or both, of these two latter forms may comprise the larger part of the sulfur content of coal, especially after it has been washed or otherwise prepared for use.

Jan 9, 1919

By A. Haghighat

The Missouri University of Science and Technology?s (Missouri S&T) Experimental Mine is a teaching and research facility which has been excavated in limestone by mining engineering students over almost 100 years. The mine is currently being extended to a second level. Available fans for ventilation are two surface fans of 24 kW and two underground booster fans of 12 kW. The design of a ventilation network in conjunction with multi surface fans and booster fans entails a complex procedure. Ventsim Visual software modeling has been used for network analysis to determine the optimum surface and booster fans locations, blade settings, and speeds. Both natural and mechanical induced ventilation pressures have been taken into account. Three working faces on each level have been designated as target points that minimum air quantities are required. The model has been calibrated against a pressure and quantity survey. Design of ductwork, door/stopping positions and different fans characteristics have been examined. The optimum flow rate at identified working faces, efficiency and minimum energy losses and annual network power cost determine the best scenario. The optimum design has been determined for the ventilation network for the next 100 years. The optimum flow rate across working faces is the key criterion selected.

Feb 23, 2014

By J. Zhang, T. Oleniuk

It is well-known that Saskatchewan has the world’s richest uranium deposits and advanced processing technologies. Unlike the Saskatchewan deposits, complicated mineralogy is common for other places in the world. Mineralogy dictates the process. Mineral Processing at the Saskatchewan Research Council has been working with the uranium industry worldwide since its inception to develop effective processing technologies to suit the unique mineralogy of each deposit. This paper reviews the research and development of uranium processing technologies in the current major uranium production areas such as Canada, as well as the potential development regions like Argentina and Sweden. Acidic and alkaline leaching processes, as well as by-product recovery technologies are discussed based on mineralogy.

Jan 1, 2020