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By C McGuire, W Harris, S Arsenault, D Witow, B Rogers

Mining deep orebodies is increasingly becoming the norm as the ‘easy’ orebodies are depleted. Deep ore mining requires significant ventilation and cooling infrastructure to not only meet regulatory requirements for air quality but also to achieve acceptable workplace temperatures with the higher strata rock temperatures and increased auto-compression. At the same time, advances in battery equipment technology are turning the possibility of a battery powered fleet into reality. The switch from a diesel fleet to a battery powered fleet offers several positive opportunities for the design and operation of a deep mine.The potential to reduce ventilation and cooling requirements due to battery powered equipment results in significant cost savings for mine development and infrastructure. Battery powered fleets are not subject to the same dilution requirements associated with diesel fleets thus allowing lower ventilation rates. At the low ventilation volumes possible with a battery powered fleet, surface refrigeration plants are limited with respect to the amount of cooling that can be delivered to the workface. Considerations for calculating the optimum air flow and cooling requirements are presented. Considerations for locating the refrigeration plant are also discussed. This paper presents these opportunities and considerations; including a case study comparing the ventilation and cooling system design with a diesel fleet versus battery fleet for a planned mine in Northern Ontario, Canada.CITATION:Harris, W, Arsenault, S, McGuire, C, Rogers, B and Witow, D, 2017. Diesel to electric – creating a positive paradigm in underground ventilation and cooling, in Proceedings Australian Mine Vent Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Musa Karakus

Ceramic build-ups are synthetic mineral deposits formed in critical locations in or near the throats of inductor units in channel induction furnaces, the preferred melting and holding furnaces used in iron foundries. The build-ups are undesirable because they slow down melt circulation, increase power consumption and cost. and decrease the quality of the metal. This study involved the determination of the mineralogy of build-up samples and the quantitative measurement of phase abundance in those build-ups by cathodoluminescence microscopy. These undesirable deposits usually are hard and dense and contain variable amounts of entrained metallic iron. The non-metallic phases dominantly consist of oxides and silicates of several refractory elements, AI, Mg. Ca, Si, and Fe. Minor amounts of the sulfides of Ca. Mg, Fe and REE elements, especially Ce and La. and the oxides and silicates of Ce and La elements are locally present in the build-ups. The build-up samples were found to be ideally suited for study by cathodoluminescence, which has provided an easy means for rapid re-cognition of the phases present in the build-ups. The phase compositions were determined by electron microprobe analysis. The phases identified and their characteristic cathodoluminescence shown in the ceramic build-up samples were: spinel (bright green, blue-green, and red). forsterite (red and purple), periclase (dark reddish-brown, blue. and orange), corundum (red, blue, orange, and white), anorthite (yellow, yellow-green, blue, and blue-purple), hibonite or calcium hexaluminate (dark green), mullite (dull red-brown), gehlenite (deep blue), silica(dark brown, pink, purple, red. and blue), monticellite (light violet blue and light pale yellow-orange), silicon carbide (orange), oldhamite (bright yellow and orange). Ce-La silicate phases (purple), and glass (orange, dull red, and purple). Non-luminescent phases were: hercynite, Fe-oxides, Ce-La-oxides, Fe-sulfides, and metallic iron.

Jan 1, 1989

By Alissa Lockett, Chris D. Breeds

Central Water Integration Project (CWIP) Segment 5-1 is the most critical segment of a regional water supply project that transfers groundwater from Burleson County to northern San Antonio, replacing over 20% of that City’s water supply with a new source. CWIP Segment 5-1 included three tunnel reaches totaling 10,350-ft and 5 shafts that were constructed inside the City in an area known to contain large karst features. This paper describes site work used to investigate the alignment for karst features, manage potential environmental impacts, develop the contract package required for mitigation and the means and methods used to mitigate the large karst features that were encountered.

Dec 1, 2022

By John Ellenberger

The nature of a stone deposit is rarely defined through exploration and engineering design, but more through the actual experience encountered as the mine develops; hence, issues with ground control are often at the forefront for a new mine. Ground control problems account for over 15 percent of lost-time injuries in underground stone mines. The objective of this work is to present actions taken during early development of a stone mine to mitigate the obvious effects of high horizontal stress on ground control. The mine was developed from a box cut with relatively little cover, and high horizontal stresses were not anticipated. Early recognition of possible high horizontal stress resulted in mapping of the mine using the NIOSH-developed Roof Fall Risk Index (RFRI) to provide a baseline to objectively analyze roof conditions. A program of borescoping the mine roof provided valuable roof beam thickness data and found that the roof beam was of minimal thickness, approximately 10 percent of drift width. As the mine developed, it became apparent that ground control problems related to high horizontal stress existed. A concentrated effort was made to improve ground conditions by implemeting a number of mitigation techniques. Actions taken by the mine included systematic roof support, reorientation of mining direction, a lower roof horizon, reduced span widths and reduced mining height in crosscuts to prevent running falls. These strategies resulted in signifcantly improved ground stability.

Jan 1, 2012

By S. Henley

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993 (original title: The database: a pre-requisite for large-scale use of AI in mining). Artificial intelligence is a term which has been widely applied to different techniques including rule-based systems using inductive and deductive logic algorithms, neural networks, learning systems and genetic algorithms. In principle it should be applied to adaptive statistical techniques. Some of these applications have been coded in languages which are specifically suited to the novel requirements of AI but are not easy to integrate with more traditional computing methods. Efforts have been made to bridge the gaps, particularly with database management systems and such efforts at integration should provide the key to future success in the application of AI. A field which has been termed "knowledge engineering" cannot be credible as such if it fails to provide easy access to raw materials of "knowledge" i.e. the data residing in databases. In the mining industry there are a number of significant areas in which AI could usefully be applied throughout the industry, but its advance is slow because of the lack or inefficiency of such database links. Current development of object-oriented database systems for geology and mining holds out hope for such integration in the foreseeable future

Apr 1, 1994

By R. L. Schmidt

One of a series published by the Bureau of Mines covering research investigations in rock drillability, this report of field drilling results extends earlier laboratory findings and provides a relatively simple procedure for predicting percussive drilling rates with reasonable accuracy. Two percussive drills mounted on a truck were used to drill a total of 25 rock types, and the results were used to develop a prediction equation. The equation was tested on a set of unrelated laboratory percussive drilling data, and the comparison between predicted and actual rates is shown in tabular form.

Jan 1, 1972

By Oliver Bowles

"Underground operation.In its broader sense the term ""mining"" is applied to all processes whereby raw materials are taken from the earth to be used as sources of mineral products. In a more restricted sense ""mining"" is applied to underground operations as contrasted with open pit work designated as quarrying. The tern is used in the restricted tense in this paper; for it relates to the exploitation of limestone deposits by modern methods of underground operation rather than by open pit methods.Present tendency toward miningIt may seem to some readers that a paper on mining limestone will find little general interest among lime plant operators, for only a limited number of them have yet resorted to this means of procuring raw materials. It is noteworthy, however, that a growing tendency exists toward underground operation, for one by one quarry owners are faced with increasing difficulties in open pit operation. It seems desirable, therefore, for operators to keep closely in touch with this gradual change in process, to inquire into the underlying causes, to compare costs, and to study the effects of the change in method on subsequent steps in calcining the stone to produce lime."

Mar 1, 1924

By G. W. Birge

Twenty-eight samples, representing the Pittsburgh, Lower Kittanning, Stockton-Lewiston, Coalburg, Winifrede, Cedar Grove, Peerless, No. 2 Gas, Powellton, and Eagle beds, were carbonized by the Bureau of Mines--American Gas Association (BM-AGA) method, and yields of products and physical properties of cokes were determined. Expanding characteristics of 22 of the samples were determined in the Bureau of Mines sole-heated oven. The Kanawha County coals tested were high-volatile A bituminous in rank, with dry, mineral-matter- free fixed- carbon contents ranging from 53.9 to 66.3 percent. With few exceptions, they were chemically satisfactory for metallurgical use, and most of the coke-strength indexes were within the industrially accepted range for high-volatile blending coals.

Jan 1, 1963

By J. R. Hauger, P. A. Romans, W. J. Niebuhr

With suitable instrumentation and techniques it is possible to determine the presence of tantalum in columbium to 20 ppm . This paper discusses the selection of X- ray spectrographic instrumentation and describes a technique for accomplishing the low level determination of tantalum . An ion- exchange method of separating tantalum from columbium is also described .

Jan 1, 1964

By J. W. Davis

In the last few years major industrial companies have begun to realize the importance of Reliability as an enterprise strategy that, properly implemented, will improve financial performance. Typical results of an effective Enterprise Reliability Strategy include a 20% -50% reduction in maintenance cost accompanied by a 5% - 10%increase in real production capacity, with no capital investment in production equipment. One factor fueling the race to acquire and implement enterprise reliability is the pressure for companies to be increasingly cost-effective and competitive in global markets. In a recent study, Asset Productivity: The Next Wave, the Boston Consulting Group (BCG)stated that, “In order to compete for funds, companies must offer investor returns that are competitive with other opportunities. Alternative investments such as dot-com and others with non-traditional business models have raised the bar.” (APDF version of the study can be downloaded at www.bcg.com). BCG views asset productivity as the most powerful mechanism for increasing shareholder return. The author believes that the most effective way to increase Fixed Asset Productivity is to maximize asset utilization by increasing the Reliability of the Assets and the associated processes. Developing and implementing an ERS requires significant effort and knowledge. Most companies have difficulty finding a sufficient supply of these valuable commodities to implement an ERS Program internally. Many companies also struggle with figuring out how to get started and what direction to proceed.

Jan 1, 2003

By H. Kenworthy

The investigations described in this report were undertaken to demonstrate, on a laboratory scale, the possibility of recovering several million pounds of tin plus tungsten contained in stockpiled and currently rejected slags from the Longhorn tin smelter at Texas City, Tex. At the same time, it was anticipated that the treatment procedures developed might be applicable to slags from other tin-smelting operations. Results of the laboratory work show that it is possible, by pyrometallurgical means, to separate the tin and tungsten into products of intermediate grade that may be returned to the smelter circuits for further upgrading. Several methods of treatment were investigated. The methods that proved effective were: Fusion reduction, chloride volatilization, sulfide volatilization, and carbide formation. Over 90 percent of the tin and tungsten could be removed from the slat by any of these methods. Each type of treatment has advantages and disadvantages, and it could not be determined from the small-scale work which method was the more meritorious. Tungsten and (in some types of treatment) tin-bearing products were diluted by iron, the separation of which will require additional studies. Prevention of a portion of the iron from reporting with the tin or tungsten is a distinct advantage and possibility that will require inure laboratory work to develop the needed techniques for its accomplishment. Tin products from single treatments of stag ranged up to 75 percent in tin content but were more generally under 35 percent. Tungsten products were usually under 15 percent; but segregated portions could be selected, at a sacrifice in recovery, that contained up to 50 percent tungstic oxide equivalent.

Jan 1, 1957

By H. E. Nold

THE raw materials of the ceramic industry are mostly clays. This raw material is ground, water is added and the mixture pugged into a moist, plastic, rather stiff mass. From this mass the desired units of manufacture are made (bricks, hollow building tile, sewer pipe, etc.). These units are dried; then placed in kilns and heated until the desired degree of vitrification is obtained.1 For firing ceramic ware, two distinct types of kilns are used; namely, periodic and continuous tunnel. PERIODIC KILNS Periodic kilns are those ordinarily seen in a brick plant. They are either round or rectangular. The raw, dried, formed ware is piled or set in the kilns to depths frequently exceeding 10 ft. The kiln is heated until the ware is matured, then gradually cooled sufficiently to allow men to remove the ware; then the cycle is repeated. The time duration of the cycle may be more than two weeks. In order that heat can be distributed uniformly throughout the pile or setting, the units are placed so as to leave open spaces or flues through-out the pile for the passage of the hot gases. Each kiln is provided with a number of fireboxes (usually 10 or 12) spaced equally in the outside wall. The fireboxes may be equipped with flat or inclined grate bars or they may have no grates at all (dead bottom). Down-draft kilns are most used. In these the hot gaseous products of combustion from the fireboxes are deflected upward by bag walls just inside the fire zone. From the top of the kiln the gases are drawn down through the setting, off through holes in the kiln bottom, and conducted to a stack or stacks. In up-draft kilns the fireboxes are usually set somewhat lower. The hot gases are drawn inward and upward through the ware and pass off from the top. Up-draft kilns find their greatest use in the firing of common brick. In either case the problem is to maintain, as nearly as possible,

Jan 1, 1933

By M. Pelegrin Rodríguez, J. Castellanos Suarez, R. Causse Miyares, A. Mosqueda Martínez, Rubén Aja

"This paper will describe the methods and the results of studies to integrate polymetallic nodule extractive metallurgy methods into existing and operating technologies or plants with the aim of reducing the capital cost of deep-sea mining challenges and to streamline the supply chain of raw materials where such opportunities exist (Moa Bay and others). It will also assess the possibility to carry out pre-industrial processing operations with productivity corresponding to pilot mining operation in the Clarion Clipperton Fracture Zone (5–10% of assumed annual production) with the use of existing facilities. The present study shows the results of high pressure acid leaching of polymetallic nodules (PN) mixed with laterite non-commercial ore. It also presents PN processing in the presence of ammoniacal tailings obtained from the Caron process. The experiments were carried out according to 24 full factorial design. The regression equations were determined for extractions of Ni, Co, Cu, Zn, Fe and Mn. The obtained results show that increasing temperature, the acid/ mineral ratio and the leaching time have a positive and significant effect on extraction of all the studied metals. However, increasing the tailings addition favors the extraction of the Co, Zn and Mn. The extraction of Fe diminishes, while the extraction of Ni is not affected. In the following conditions; 180 min, 260°C, 0.5 kg acid /kg minerals and 2.5 kg PN/kg tailing; the following extractions were achieved; 96% Ni, 90% Co, 97% Cu, 99.9% Zn, 43% Mn and 26% Fe."

Jan 1, 2017

By Justin Carl, Aliuddin Mohammad, Gordon Evans, Steven Bealby, Carlton Ray

"The District of Columbia Water and Sewer Authority (DC Water) is implementing the $2.2-billion DC Clean Rivers Project (DCCR) to control combined sewer overflows (CSO) to the Anacostia and Potomac rivers and Rock Creek, and to provide flood relief to the Bloomingdale and LeDroit Park neighborhoods in the District of Columbia. The long-term control plan complies with the requirements of a Federal Consent Decree entered into by DC Water, the District of Columbia and the United States, as represented by the U.S. Environmental Protection Agency and the Department of Justice. The Northeast Boundary Tunnel, a design-build project, will store combined sewage and deliver it to a system of downstream tunnels and ultimately to the Blue Plains Advanced Wastewater Treatment Plant (Blue Plains), where it will be treated. In addition, the Northeast Boundary Tunnel (NEBT) is a major project associated with the mayor’s task force to alleviate extreme flood events in Bloomingdale and LeDroit Park. The Northeast Boundary Tunnel Utility Relocations (NEBTUR) design-bid-build (DBB) project is an accelerated component of the Anacostia River System, as shown in Fig. 1. During dry weather conditions, the entirety of the sewage in the combined system is conveyed to Blue Plains.During storm events, when sewer pipe capacity is exceeded, the flow, which is a mixture of sewage and stormwater runoff, overflows into receiving waters through outfalls. There are a total of 47 active CSO outfalls along district waterways.The influx of storm runoff into the combined sewer has an additional impact on the communities of Bloomingdale and LeDroit Park. The sewer system is outdated and undersized. In these neighborhoods, when the capacity of the sewer is exceeded, localized flooding occurs and backups into adjacent residences are prevalent. In any given year, there is a 50-percent chance that flooding will occur in these neighborhoods."

Jan 9, 2017

By G J. Lyman, S A. Tittlemier

International regulations exist to manage the concentrations of mycotoxins such as Ochratoxin A (OTA) and deoxynivalenol (DON) in grains and prevent health risks from excessive exposure to OTA and DON. Since the permitted levels of these mycotoxins are very low (existing maximum levels are in the range of 5 ppb for OTA and 1–2 ppm for DON), sampling for these mycotoxins is potentially challenging. Given that the distribution of infected kernels in a consignment of wheat can be highly heterogeneous, detection by current sampling methods is subject to a high variance. Furthermore, the concentrations of mycotoxins in individual kernels vary over orders of magnitude, intensifying the heterogeneity of the bulk grain.In these circumstances, there is much interest in developing sampling plans that inform regulatory agencies, and mitigate the risk of misclassifying grain shipments as compliant or non-compliant within the global grain trade, when correctly implemented.Experimental data from laboratory and field studies describing individual wheat kernel concentrations of OTA and DON were combined with experimental data describing the variance due to the analytical methods used for OTA and DON to calculate the sampling distribution for wheat having various levels of contamination. This work has focused on quantifying the heterogeneity of samples at the point of submission for analysis and within subsequent sample preparation to arrive at total sampling distributions that include uncertainties due to the intrinsic heterogeneity and the analytical uncertainties. The sampling uncertainty that relates to the difference between the primary sample analysis and the true lot analysis is not included as it has been dealt with elsewhere.CITATION:Lyman, G J and Tittlemier, S A, 2017. The sampling characteristics of grains contaminated by mycotoxins, in Proceedings Eighth World Conference on Sampling and Blending , pp 281–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Carlos Collado, Oscar Jimenez, Francisco Diaz, Rodrigo Bernal, Carmen Salinas

Water is a strategic resource for the mining industry. The rising cost has forced the industry to become more efficient in their use, reduce and recycle waste as much as possible. The importance of having a reliable water balance is increasingly urgent, because the resource is scarce and vital to the sustainability of human life, animal and ecosystem. Conventional flowmeters can suffer disruptions or failures by corrosion, fouling, presence of elements in the water as acids, salts and suspended solids. Use of radiotracers is advantageous to determine fluid velocities that are transported through pipes, as they are detectable by means of the radiation emitted, the same way for surface flows, such as natural watercourses and drainage from tailings dams, fluorescent tracers are those with the best advantages. For velocity measurements in pipelines a Iodine-131 tracer solution, around 5 mCi was injected into the suction of the pumps. The technique used is the transit time between detectors at known distances and determining the time of passage of the radiotracer. For measurements of surface fluxes using the fluorescent tracer Rhodamine WT by tracer dilution technique, injecting the tracer at a constant rate and measuring it known concentration diluted downstream. This work has been performed in Minera Los Pelambres, located in the IV Region of Chile, measuring the flow rate pumped from 12 pools with 1-7 pumps operating, obtaining speeds of 0.56 to 2.62 m/s. In pumping wells three facilities have been measured at speeds of 0.111-0.223 m/s, plus six surface flows with flow rates of 8.45 to 357.2 L/s.

Jan 1, 2014

By George S. Rice

[This paper gives the details of tests to determine the design of stoppings capable of withstanding a pressure, applied to either side, of 50 pounds per square inch,6 as required by section 104 (a) of the Operating Regulations to Govern Coal-Mining Methods on Leased Lands on the Public Domain, issued in 1921 and quoted oil page 3. The regulations stipulated that the design for such stoppings must lie approved by the United States Bureau of Standards. The engineers of that organization felt that knowledge of the strength of such structures with respect to the effect of explosion pressure in comparison with static pressure and the strength of the walls which furnish the abutments was insufficient to justify drafting specifications; therefore, tests were needed to give information upon which a rational system of design could be based. A study was then begun; and several series of tests, made by the United States Bureau of Mines and the United States Bureau of Standards in cooperation, grave information upon which are based the detailed specifications offered in a later section. Slabs representing concrete stoppings, with and without reinforcement, were tested at the Bureau of Standards in Washington D. C.; afterwards, full-scale stoppings were tested at the Bureau of Mines Experimental mine near Pittsburgh. It was assumed that in most coal mines the strength of the floor and roof could not be relied on, but dependence must be placed upon the strength of the coal ribs. The tests developed that the maximum strength of an unreinforced concrete stopping was obtained when it acted as a flat arch buttressed against the coil ribs; but its ultimate strength depended upon the resistance to movement offered by the coal strata against which its ends were restrained or buttressed.]

Jan 1, 1931

By B. Valentim

The methodology used to obtain fly ash subsamples of different sizes is generally based on wet or dry sieving methods. However, the worth of such methods is not certain if the methodology applied is not mentioned in the analytical procedure. After performing a fly ash mechanical dry sieving, the authors compared those results with the ones obtained by laser diffraction on the same samples and found unacceptable discrepancies. A preliminary study of a wet sieving analysis carried out on an economizer fly ash sample showed that this method was more effective than the dry sieving. The importance of standardizing the way samples are handled, pretreated and presented to the instrument of analysis are suggested and interlaboratory reproducibility trials are needed to create a common standard methodology to obtain large amounts of fly ash size fraction subsamples.

Jan 1, 2008

By E. R. Palowitch

On February 5, 1973, Eastern Associated Coal Corp began shortwall mining in their Federal No. 1 Mine, thus marking the first attempt in the United States at modern shortwall mining, i.e., using a continuous miner to extract coal open-ended from pillars 100 to 200 feet wide, under the protection of a self¬-advancing roof support system (1)1/. Since then, four additional shortwall faces have been operated. While the number of face-years of shortwall experience in the United States is limited, this experience has been anything but uniform. Differences in operator motivation, coalbed parameters, geologic conditions, panel dimensions, and face equipment all have contributed to a wealth of knowledge which can provide guidance for the design of future shortwalls. The purpose of this paper is to review the history of shortwall mining in the United States and to assess its value to the U.S. coal industry in terms of the health and safety of the miner, the percentage of coal recovered, coal production, worker productivity, and relative cost performance.

Jan 1, 1976

By V. M. Hamza

Analysis of ground and airborne radiometric measurements in the Saquarema region (Rio de Janeiro) provides new insights into the breakdown and transport of mineral aggregates containing monazites, under sub-tropical weathering conditions. The breakdown process, accompanied by loss of low-density clay fractions in weathered materials is considered responsible for the observed patterns in relative enrichment of thorium and uranium along the migration paths of radionuclides. The characteristic features of these patterns provide clues as to the time and distance scales associated with processes of weathering and erosion. It is also possible to determine approximate locations of concentrations of accessory minerals. In this context, we advance the hypothesis that large under-water monazite deposits may be present along the offshore sand banks, in the coastal region of the state of Rio de Janeiro.

Sep 14, 2011