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By D Brouwer, P Wild, B Belle

Due to the steep geo-thermal gradient in Bowen Basin area, as underground coalmines reach increased depths of extraction, the Bulk Air Cooling (BAC) requirements will increase as opposed to cooling the workplace using the ventilation means alone. One such mine has already been using a 4 MW surface BAC plant for the last six years to manage the working temperatures with reduced cooling efficiency as the mine expands. Due to the horizontal nature of the longwall mine layout, distances from the working face to intake shafts are rapidly expanding to over 6 km as opposed to the vertical mine layout of a hard rock mine. To improve the positional cooling efficiency, reduced panel pressure differentials, improved rib emission gas management, and intake dust management, small diameter intake shafts were located on the inbye end of production panels and halfway up the development panels with localised mobile small BAC plants. This paper summarises the results of extensive underground data of this innovative cooling concept for development and retreating longwall face heat management compared to a larger remote BAC plant.CITATION:Belle, B, Brouwer, D and Wild, P, 2017. The use of mid-panel ventilation shafts to improve positional cooling efficiency in a Bowen Basin longwall mine – a case study, in Proceedings Australian Mine Vent Conference 2017, pp 217–224 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Ramsey Hart

MiningWatch Canada is the only national independent civil society organization with an exclusive focus on mining in Canada and Canadian mining companies operations internationally. In 2005, MiningWatch Canada collaborated with other NGOs to develop the Framework for Responsible Mining: A Guide to Evolving Standards. The project was the result of a perceived need by NGOs and retailers, particularly from the jewellery sector, for a framework that would set out environmental, social, and governance standards for the minerals sector ?providing recommendations for retailers and others seeking to source or invest responsibly, as well as regulate and encourage responsible mining practices?. This paper is a reflection on the Framework that examines key areas of concern and notes where the industry norms and expectations of civil society have evolved. The paper focuses on developments in social issues related to the UN Guiding Principles on Business and Human Rights, new initiatives associated with financial transparency, the UN Declaration on the Rights of Indigenous Peoples. The environmental components of the Framework that are revisited are waste management, biodiversity, energy and climate change, environmental assessment, mine closure, mercury and seabed mining.

Aug 1, 2013

By Xing Zhao, Michael A. Sutton, Vikrant Tiwari, Damien Bretall, Xiaomin Deng, William L. Fourney, Uli Leiste

The dynamic response of a thin aluminum plate subjected to both shallow and deeper buried blast loading was studied. Using a combination of high speed stereo-vision and three dimensional digital image correlation (3D-DIC), sequential stereo images acquired every 38.25µs during blast loading were analyzed to determine full-field deformations and plate motions (displacements, velocities and accelerations, effective surface strain and effective surface strain rate). Measurements indicate that the initial sheet deformation was highly localized for both shallow and deeper blast events, with extremely high velocity and acceleration values recorded during the earliest stages of impact loading. Full field strain and strain rate data indicate that well defined strain and strain rate “maxima” are created in the plate, with the potential of affecting the dynamic plate behavior as well as it local failure.

Jan 1, 2010

By J Temos

This paper outlines a number of immediate practical approaches to continuous improvement in environmental management in the minerals industry. It puts these into context with longer time-frame step-change approaches whose gestation may take a decade. Examples of improvements and approaches are drawn from WMC operations.

Jan 1, 2002

By Reinaldo J. Villa, Joshua C. Adams

The I-395/SR-836/I-95 reconstruction project is an $818-million design-build construction effort that includes construction of viaduct, segmental and signature bridges in Miami leading into Miami Beach in Florida. Based on the load testing performed during the design phase, the design-build team determined that conventional driven pile and drilled shaft foundations were not feasible for support of segmental and signature bridges. Due to the weak limestone formation and successful use of auger cast-in-place (ACIP) piles in the Downtown Miami area on commercial developments, ACIP piles were selected as a foundation system to support bridges. This is the first time in history where the bridges will be supported by ACIP pile foundations in an interstate highway in the State of Florida. The design build-team worked closely with the Florida Department of Transportation to develop requirements for the load test program. The paper will provide an overview of the geotechnical data collected, results of dynamic/bi-directional load testing performed on test piles, data collected, installation of piles, and lessons learned. The load test program included a total of fifteen test piles with dynamic, bi-directional, and lateral load testing on 30 and 36-inch diameter ACIP piles and instrumented with thermal integrity profiling wires.

Sep 8, 2021

By David A. Hill, James R. Wait

This report contains a summary of analytical research on electromagnetic methods of nondestructive testing of cylindrical conductors. The principal objective is to provide theoretical insight to the operation of electromagnetic sensing of the internal properties of wire ropes that are used extensively in mine hoists. An overall review of past work is also included.

By A. W. Asman

The problem of balanced design in a belt conveyor has been under constant study. Increased use of this method of transport in recent years has stimulated investigations. Conveyor belt, power transmission and other machinery should be adequate to perform the required service. All components of the belt conveyor should work as an efficient unit moving its load continuously between terminals. As part of a long term research project on belt conveyors, Hewitt-Robins established in 1954 a 2-year grant at Pennsylvania State University. Under terms of the grant, certain fundamental phenomena were to be studied. This work evolved a new concept in belt conveyor power determination based on the principle of belt tension. The Penn State contract furnished the foundation for later more detailed studies. From these most recent investigations, more specific factors were defined. In the final analysis, all of the data collected has been worthwhile in belt conveyor design. Units now operate over long distances at speeds of over 800 fpm. Long high lifts are commonplace. Where vertical or inclined shafts were the rule, belt conveyors receive first consideration. Although belt conveyors have moved forward rapidly, the future will see a tremendous gain in their use. The ideal test belt conveyor would be several thousand feet in length and have a maximum tension of at least 70,000 lb., Also, this conveyor should be horizontai and have a variable feed rate of more than one material. Data from such a field belt conveyor combined with laboratory information would permit accurate analysis. Since this type of conveyor was not available, many field locations were visited: An alternate would have been to erect a closed circuit system in the laboratory. Either method had limitations and the first was selected as having the best possibilities. Manufacturers of conveyor belting and machinery basically have been using the same horsepower formula. As more information became available from field installations, factors in the basic formula were modified. Practically all conveyors are designed today by adding together the horsepowers required to move the empty belt, move the load horizontally, and elevate the load. In selecting size of drive motor, the first two elements are relatively unimportant if the last is large. However, it is the combination of

Jan 1, 1961

By Forrest T. Moyer

INJURY experience and employment data are presented in this chapter for metal and nonmetal mines, stone quarries, sand and gravel pits, iron blast-furnace slag plants, and metallurgical plants (including ore-dressing and nonferrous reduction plants and refineries) in the United States. Employment and injury experience data for all mineral industries are given in volume II. The 1962 figures are preliminary summations which are subject to revision. They were compiled from all reports from producers received by the Bureau of Mines through April 15, 1963. The data for metal, nonmetal (except well and brine operations), stone, and sand and gravel operations were collected by a mandatory reporting system under the provisions of the act of September 26, 1961, Public Law 87-300 (75 Stat. 649). The act authorized the Secretary of the Interior to study the various aspects of safety in metal and nonmetal mines (excluding coal mines) and report the findings 2 years sub-sequent to the enactment of the law. Data on nonmetal well and brine plants and nonferrous reduction plants and refineries were reported voluntarily by the operators. METAL MINES Preliminary data for the metal mining industry comprise reports on 1,871 mines and pits. The combined fatal and nonfatal injury-frequency rate was 31.95 per million manhours in 1962, a decrease of 8 percent from the similar rate of 34.54 in 1961. Metal operations reported a total of 61 fatal and 3,201 nonfatal injuries.

Jan 1, 1963

By L. F. Willmott

The Bureau of Nines at Morgantown, W. Va., has been investigating, on a pilot plant scale, various methods of gasifying bituminous coal with oxygen and superheated steam to produce synthesis gas, as part of the broader program of finding new uses for coal. Differences in the pressure gasification methods used have depended on differences in the manner in which the pulverized coal is fed to the gasifier. One of the methods of feeding the coal that was investigated was the continuous, integrated coal-water slurry system. Goal and water were first mixed to produce a slurry; then the slurry was pumped through a heated coil. to evaporate the water fraction; the resulting steam was superheated, and some of it was separated so as to adjust the ratio of the residual steam to the coal fraction and make the resulting mixture suitable for partial combustion with oxygen in a pressure gasifier. Both before and during this reported3 developmental work it was necessary to make an extensive literature search into the technology of aqueous slurries in order to establish design criteria for the pilot plant and to correlate results of various phases of the work with that of other investigators, The pilot work coincided with the commercial development of a long-distance pipe- line for the transportation of coal as a coal-water slurry, and this fact tended to broaden the scope of the pilot plant work and the extent of the literature search. This bibliography is the compilation of the material that was collected.

Jan 1, 1963

By David L. Veith

As the basis for the State of Minnesota's Regional Copper-Nickel Study environmental evaluation, hypothetical mine models were developed ranging in ore capacity from 5.35 to 20.00 x 106 mtpy. Open pit and underground mining operations were defined utilizing conventional methods of ore extraction. Processing of the copper-nickel sulfide material involved conventional bulk flotation of the valuable minerals, with maximum water recycle And tailing disposal. Flash smelting and electrolytic refining of the concentrate resulted in 0.10 x 106 mtpy copper plus nickel metal, plus associated cobalt and precious metals. Variations in model parameters allowed environmental trade-offs to be identified.

Jan 1, 1980

By Pavel Vasak

Microseismic monitoring has become standard practice in the mining industry as a ground control monitoring tool at depth. Translating the information into practical hazard assessment tools for the rock mechanics practitioner is the focus of research jointly conducted at Creighton Mine by INCO Mines Technology Centre (MTC) and the Geomechanics Research Centre (GRC) in Sudbury, Ontario. Rock mass damage mechanisms are typically related to stress and the presence of geological structures. Due to well executed de-stress blasting practices at the mine, stress related problems are minimized. However, structurally related damage mechanisms associated with shear zones, faults and joints pose a substantial hazard. Identifying active structures from the dataset of seismic and microseismic events is generally problematic. We propose a new methodology that uses a combination of spacetime event density, hierarchical clustering and principal component analysis to identify planes of microseismic activity, termed active planes (APs). Once identified, the presence and intersection of active planes can be used to provide a hazard ranking for nearby excavations. The ranking is based on the standard Q rock mass classification system, with emphasis on the joint set number (Jn) and stress reduction factor (SRF) parameters. If the rock is treated as a fractured continuum, then, the Jn indicates the degree of freedom for blocks to move and hence, increased potential hazard. An increased hazard can also result if the APs are larger-scale and discrete (faults) rather than ubiquitous (joints). In this case the SRF is used as a measure of the degree of looseness in the rock mass.

May 1, 2004

By Mark K. Larson

Researchers at the National Institute for Occupational Safety and Health?s (NIOSH) Spokane Research Laboratory are developing a borehole profilometer to dynamically measure the roughness pro-file of boreholes used to install roof bolts fully encapsulated with resin. Numerical measures of roughness were calculated from profiles of borehole surface roughness to determine potential roof bolt anchorage capacity. The concept of dynamically profiling was proven through the following series of laboratory tests: a sensitiv-ity test using various grits of sandpaper, a known-profile test along a section of a concrete hole, and a simulated borehole test in a pipe with machined grooves. Two profilometer prototypes were devel-oped that measure slight changes in the radius of a borehole using either strain-gauged, spring-steel arms or rigid, steel arms attached to a spring-loaded cone and a linear potentiometer. Both instruments performed reasonably well in the laboratory and were subsequently tested in boreholes drilled in two concrete blocks using different drilling techniques to obtain three different borehole surface roughnesses. A Z2 roughness parameter was calculated with data from the first profilometer, and an average radial increment was calculated from the test results of the second profilometer. Although both instruments were able to readily distinguish the difference between smooth and rough boreholes, the correlation coefficient (r2) for a linear relationship between Z2 and average radial increment was 0.577. Pull tests were conducted with resin bolts installed in the concrete blocks, but maximum pull-out strength could not be correlated to borehole roughness because in each of these tests, failure occurred at the resin-bolt interface. A more sophisticated prototype has been designed to measure surface roughness and also accurately determine the location and tilt of the instrument in the borehole. However, this instrument has not yet been fabricated or tested.

Jan 1, 2007

By E. H. Smith

"The El Indio mine treats a complex mixture of copper and gold/silver ores at its plant located in the high Andes in Chile. The plant utilizes conventional crushing, grinding and flotation to produce a copper/gold/silver concentrate. Due to high levels of arsenic and antimony, the flotation concentrate must be roasted prior to custom smelting. The flotation tailings is leached and additional gold recovered from a CIP circuit. Present and future metallurgical developments are discussed in this paper. INTRODUCTIONIn late 1989, LAC Minerals purchased 65 % of Bond International Gold and as a result became controlling shareholder of the El Indio Mine through Bond and San Jose.El Indio is a world class, complex sulphide gold deposit located in the hydrothermal alteration belt of the Andes mountains in the 4th Region of Chile. The mine is located in the high Andes about 185 km east of La Serena at an elevation of 4000 meters. The 1450 workers at El Indio live in the mine camp at 3200 m and on days off are bussed to La Serena.The El Indio mine was started in 1979 by St. Joe Minerals Corp., bought by Bond in 1987 and subsequently by LAC in 1989. The mine has produced 2.7 million oz. of gold, 9.5 million oz. of silver and 170,000 t of copper since start of operation. The mill is currently operating at a rate of 2850 t/d and producing a copper/gold concentrate which is roasted to produce a copper/gold calcine and high quality, saleable crude AS2O3 . A small proportion of the precious metals are also produced as bullion from the leach circuit.Total production during 1989 was 224,197 ounces of gold, 1,309,342 ounces of silver and 26,968 tonnes of copper. The average cash cost of production for the period was U.S. $96 per ounce of gold, net of by-product credits. The average realized price was $5. 30 per ounce of silver and $1.14 per pound of copper."

Jan 1, 1991

By J. M. Toguri, K. Grjotheim

It is known 1,2 that the equilibrium between titanium metal, TiCl2 , and TiCl3, in a solvent of molten metal chlorides, is influenced both by the total amount of dissolved titanium and by the type of solvent. Assuming that the trivalent titanium forms the complex ion Ti111 Cl4, the equilibrium reaction may be expressed by the following equation, (Me) TiIII cl4+ 1/2 Ti = 3/2 TiII cl2+ (Me) Cl The ideal ionic equilibrium constant for this reaction is, Where the N's are the molar ionic fractions in the equilibrium melt, and (Me) the different types of cations present in the equilibrium mixture. The following thermodynamic relation is derived between Kand the concentration of cations in the equilibrium melt, mix The N"S are the equivalent ionic fractions, and so forth are constants corresponding to the standard changes in free energy for reactions in melts where only the cation indicated is present, and f (y1) is a function of the activity coefficients in the equilibrium mixture. When this term vanishes, a simplified linear relationship between In Kideal and the concentration is obtained. The simplified relationship has been applied with satisfactory results to the experimental data of Mellgren and pie,' and Kreye and Kellogg.2 MANY existing methods for the production of light metals involve the reduction of their respective metal halides in the presence of salt melts composed of alkali or alkaline earth chlorides. In such a solution phase, the light-metal halide may undergo stepwise reduction from a higher, to a lower valence, and finally to a zero valent state. In this connection, the disproportionation equilibrium is of great interest. In the case where the higher valence is three and the lower valence is two, the disproportionation equilibrium may be written as follows, 3 Me11 = 2 Me111 + Me [I] If this equilibrium occurs in a salt melt containing a large excess of alkali chlorides, a typical ionic melt is obtained. It is then possible to formulate the cation equilibrium: 2 Me+h' + Me = 3 Me++ [II] Reaction [11] is analogous to a cation exchange reaction. It has been shown thermodynamically that the equilibrium constant for such a reaction in 2

Jan 1, 1960

Objective The main purpose of this video is to teach mine rescue personnel certain aspects of rescue work that are not traditionally taught. These include the strain caused by working continually under adverse conditions; the "survivor guilt" that occurs from being spared the fate of one's deceased cohorts; and the posttraumatic stress that may be experienced during the sometimes lengthy task of recovering the victims' bodies. Background On November 20, 1968, an explosion rocked the Farmington No. 9 Mine in northern West Virginia (figure 1). The explosion killed 78 of 99 miners who were working in the mine, including all but one member of the mine's rescue team. Some 30 years after the event, researchers from the NIOSH Pittsburgh Research Laboratory (PRL) conducted a video interview with Danny Kuhn (figure 2), the only Farmington No. 9 mine rescue team member who was not working that day and who did not die in the explosion. According to the Mine Safety and Health Administration (MSHA), there are about 80 underground coal mine rescue teams in the United States, and according to the National Mining Association, there are more than 850 underground coal mines. This represents a significant decrease in both over the past decade. The low number of rescue teams is a concern because serious incidents, though fewer, still happen, and if a disaster occurs, there will be fewer rescue teams to respond. This would result in an increased need to use available human resources very efficiently. Much training to prepare these rescue teams still takes the form of what educators call "teaching to the test." In other words, teams practice in order to win mine rescue contests. This test-oriented approach has traditionally been augmented by interactions with others who have responded to real situations or by participating in actual incidents. Given few incidents and fewer rescue teams from whom to derive enrichment, the preparation of coal mine rescue personnel becomes a problem. Recently, more emphasis has been placed on active learning, such as working out problems in smoke. These sessions more nearly simulate the actual conditions that today's team members might rarely encounter. To properly prepare and retain the current coal mine rescue personnel who are left in the workforce, it is necessary not only to offer such hands-on experience, but also to replace the learning narratives that once were passed from team to team. The present video is intended to contribute in that capacity. Approach NIOSH researchers first learned of Mr. Kuhn in the fall of1998. Mr. Kuhn was contacted and agreed to an interview. An oral history interview was conducted with Mr. Kuhn in early November1998. After reviewing the videotape of the interview, researchers determined the content to be so rich as to warrant a second interview in a more formal setting. The second interview was done in early December 1998. During this interview, Mr. Kuhn spent about 2 hours describing the Farmington disaster, including the workplace climate leading up to the explosion, the events that took place in the 10 days after the explosion, and the nearly 10-year effort to safely and successfully recover most of the victims' bodies. The videotape of the second oral history interview with Danny Kuhn was reviewed and edited by NIOSH researchers for content. Careful attention was used to ensure that valuable information was presented, but within a reasonable timeframe. A detailed map of the Farmington No. 9 Mine was edited into the final video and used to highlight critical features as they were being described by Mr. Kuhn. Results and Accomplishments A 60-minute videotape and instructor's guide for use in safety training or other settings was completed. The target audience consists of all those who work in underground coal mines. This training video will help safety instructors better prepare mine rescue team members for the situations that they will encounter when engaging in extended rescue and recovery work. As a result of this expectations training, team members will be more likely to serve their

Mar 1, 2002

By V. Galla

Waste rock facilities (WRF) generally have a large footprint depending on the strip ratio the mine plan provides. Considerable planning is involved during the initial phase of the mine plan regarding the location of the WRF. As the mining operations are commenced the locations of the WRF change accordingly with the variations in the mine plan involving feedback and support from local communities and stakeholders. Waste rock facilities management becomes challenging when the area available for placement is limited due to terrain topography, environmental and permitting constraints. Risks associated in the design of waste rock facilities constitute particle size of rock, chemistry associated with the rock for reactivity and stability of the over all facility. This paper will provide some insights on designing, scheduling and managing a WRF. Emphasis on geotechnical, geophysics and geochemistry aspects of waste rock with reference to design, construction process and scheduling of WRF are also presented. Design improvements in the reclamation slope of WRF for erosion control will be discussed. Continuous improvement (CI) methodology will be introduced in the process of WRF operations. Current practices and future recommendations towards sustainability and consistency in operating WRF will be discussed in conclusion.

Jan 1, 2011

By J. R. Goode

"Coarse ore sorting is here defined as the physical separation of a mixture of coarse (+3/8 inch) ore particles into two or more separate groups of total value greater than that of the unsorted ore. An ore will probably be sortable if the geology of the orebody and the mining practices employed meet conditions outlined in this paper.The paper points out how sorting can substantially reduce tonnage variable operating costs because sorting can double the mill head grade of amenable ores by rejecting waste rock from the mine output. The effect of sorting on ore reserves is outlined. It is also suggested that sorting is a low cost alternative to conventional expansion.The mode of operation of the Ore Sorters Kadel 13 Photometric and MK VI A Radiometric sorters is detailed. The report concludes with detailed descriptions of the photometric sorting plant operated by the Doornfontein Gold Mining Company is South Africa and the Radiometric Sorting Plant presently under construction at the Schwartzwalder mine of Cotter Corporation in Colorado."

Jan 1, 1975

By Bradford NL

The Isa Mine of Mount Isa Mines Limited produces 2.6 million tonnes of silver-lead-zinc ore annually from sub level open stopes of which approximately 40% comes from the narrow Racecourse orebodies below 15 level.Geologically the stoping environment is complicated by highly fissile shale hangingwalls and below 17 level by a high stress regime.The realization that major hangingwall failures and generally poor ground conditions could lead to serious dilution problems, and ultimately production shortfalls, prompted investigations into the use of low strength explosives.

Jan 1, 1985

An Integrated Solid Waste Management Method for Western Macedonia, Greece

Sep 13, 2010

By T. E. Gray

This report describes the preparation characteristics of the significant coalbeds in Nicholas County, W. Va. It is one in a series describing coals suitable for producing metallurgical coke, either as mined or after beneficiation. Almost 5 million tons of coal were produced in Nicholas County, W. Va., in 1960, of which over 2.6 million tons were cleaned in eight preparation plants. It has been estimated that over 6 billion tons remained in the county as of December 31, 1960, in beds 12 inches and more thick.

Jan 1, 1962