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By D. E. Wolfson

As part of its overall program of coal carbonization, the Bureau of Mines is studying the coking properties of coals that may be used for metallurgical purposes. The objectives of this study were given in detail in a previous report.2/ The suitability of coal for metallurgical use depends primarily on (1) chemical composition, (2) preparation characteristics, and (3) carbonization behavior. The first two factors, as well as the available reserves, are considered in selecting coals for carbonization tests. According to the estimate of reserves by Dowd,3/ the recoverable coal in Raleigh County in beds 28 inches or more thick, in thousand tons, is: [ ]

Jan 1, 1957

By R. R. Sayers

The contemplated use of dichloro-difluorco methane in domestic and commercial refrigerating appliances and in air-conditioning equipment for public buildings and possibly homes, brims attention to the health hazards involved in a wide potential exposure of the public to vapors of another new product, and for the first time to vapors of an organic fluorino compound. The objective in the development of this new refrigerant, however, has been the mitigation of health and explosion hazards in automatic refrigeration, and accordingly these factors have been given primary attention. Early in the development, the Bureau of Mines as requested to make a laboratory study of the toxicity and potential hazard, and it was ca the oasis of the results is of this work and the results of a preliminary investigation made in another laboratory6 that the compound has been selected for commercial use. The investigation conducted by the Bureau of Mines is still in progress, enough information has been obtained to indicate the order of the toxicity and the magnitude of the health hazards involved in the use of dichloro-difluoro methane as a refrigerant. The following is a summarized report of the work completed to date:

Jan 1, 1930

By Genrich A. Denisov

Principles of ecologically friendly geo-technologies construction are formulated on the basis of the works of the leading scientists in the field of rational processing of mineral resources of the Russian Academy of Sciences. One of these concepts is a new direction in rotational disintegration of mineral and technogenic raw material with the purpose of effective subsequent enrichment. A large amount of practical experience has been accumulated in the industry on selective destruction by application of vibrational method on initial material with consideration of its physical-mechanical properties and mineral structure. This method is successfully realised in a conic inertial pulverisation devices constructed by Mekhanobr Institute (St.-Petersburg). A new construction of conical-inertial pulverisation with a modification of disintegration force has been developed recently at Mekhanobr Institute. It allows, in some cases, to increase selectivity of subdivision and to avoid over-disintegration. Advantages of “wet” subdivision methods in conic inertial disintegration devices are proved. The efficiency of such subdivision can be increased due to rational use of the phenomenon of a dislocation-dynamic diffusion. Its advantage is proved by the effect on disintegrated material by frequency-modulated variable electrical fields of low power. It was shown in industrial conditions, that the productivity of the spherical mill can be increased by 10 %, and that it also prevents ecologically harmful surface active substances (SAS) in milling zone and it reduces the dust content in the air. The techniques of tentative estimation of efficiency of various proceedings technogenic materials and their classification are created. The scientific fundaments of rational, ecologically friendly technology of processing and regeneration of various kinds of technogenic raw material are developed. A number of effective technologies on processing of wastes is developed and inculcated in concentration factories and metallurgical factories.

Jan 1, 2003

By R G. Barker, A B. Christie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. More than 11 Moz of Au and 50 Moz of Ag have been produced from epithermal deposits in New Zealand, almost entirely from 50 deposits in the Hauraki goldfield. Since the 1980s, new deposits have been discovered at Waihi (Favona, Trio, Correnso) and nearby at Golden Cross. Feasibility studies into reopening the Talisman mine at Karangahake are continuing, and advanced projects with preliminary inferred resource estimates are reported at Wharekirauponga, Neavesville and Muirs. In the Taupo Volcanic Zone, 11 prospects have been drilled, resulting in the definition of large but low-grade Au-Ag resources at Ohakuri. In Northland, several Au, Ag and/or Hg prospects are known, and small quantities of Ag and Hg have been mined. Six prospects have had some drilling, with the most advanced exploration at Puhipuhi. The application of Taupo Volcanic Zone geothermal systems research to the modelling of former hydrothermal mineralising processes in some epithermal prospects has enabled better targeting of exploration.CITATION:Christie, A B and Barker, R G, 2015. Exploration for epithermal gold deposits in New Zealand, in Proceedings PACRIM 2015 Congress, pp 533–540 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By W. G. Pariseau

Introduction Caverns of 50 m in linear dimension at depths below 2300 m with a life of more than 25 years are proposed for the next generation of water-filled neutrino detectors. Little precedent exists for excavations in such an extreme environment, although some guidance is available from mining experience at great depths, for example, in South Africa, in Canada and at the former Homestake Mine in the U.S.A. Unlike mining for ore, there are choices available in the construction of such caverns that may mean the difference between success and failure. These choices should be informed by rock engineering principles. Recently proposed guidelines for orientation of brick-shaped caverns where the long dimension is a small multiple of the short dimension indicate that the most favorable orientation is with the long and short dimensions parallel to major and minor preexcavation principal stresses (Pariseau, 2005). Numerical analyses at reduced strength indicate some yielding at cavern walls should be expected but that an equilibrium state is quite possible and is aided by arching the back into a spherical dome when the cavern is an empty cylinder (Tesarik and others, 2002). The same indications of stability occur with brick-shaped caverns. However, the most dangerous situation occurs during the excavation sequence to final cavern dimensions. There are any number of excavation sequences that lead to the same final cavern shape, so there is an opportunity to partially optimize the sequence with construction guidelines that minimize peak stress concentrations during construction. This contribution discusses three practical excavation sequences that lead to the same brick-shaped cavern in the strong, massive Yates formation at the Homestake Mine where considerable rock mechanics data has accumulated through the years(e.g., Pariseau, 1985, Pariseau and others, 1995) and where actual mining on the 8000 Level indicates a strong possibility of successful investment in the next generation of large, deep neutrino detectors. The main results are: (1) a favorable brick-shape is one with dimensions in the same proportion as the preexcavation principal stresses (compressionpositive), and (2) favorable orientation of the most extreme but temporary shape of excavation is also best for the construction sequence. Analysis results from a mix of Homestake Mine data and possible excavation geometry illustrate the advantages of these guidelines.

Jan 1, 2006

By N van Aarde, B A. Moore, S van der Merwe

Frequently materials handling operations are compromised by transfer chute problems ranging from high wear rates, blockages and ineffective loading of the downstream conveyor. This paper will present the design flow implemented to overcome problems in two case studies utilising discrete element modelling incorporating material characterisation.Material testing is relevant in achieving a valid discrete element method (DEM) simulation model and subsequently a valuable design tool for transfer chute assessment and design. It is well recognised that in the current growth and demand for mineral resources, leading to ever increasing conveyor capacities associated with export terminals and mineral processing facilities that transfer chutes are a key focus point. The successful performance of the transfer chute is also dependent on operating with a ærobust rangeÆ of material flowability and handling characteristics. This requirement is crucial in accommodating mineral ores from developing resources, which are often more friable and stickier than in past decades.This paper will include details of chute installations associated with iron ore and coking coal, from the DEM simulations through to the performance of the installed and commissioned plant.CITATION:Moore, B A, van der Merwe, S and van Aarde, N, 2013. Implementation of advanced transfer chute designs, in Proceedings Iron Ore 2013 , pp 445-450 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By By Staff

"Acid mine drainage can be controlled by water treatment, retardation of the pyrite oxidation reaction system, or enhanced prediction that allows preventive action to be taken. The Bureau of Mines is conducting research in each of these areas; the results of this research are summarized in the eight papers that comprise this volume. Field work to evaluate overburden analysis, alkaline injection, and bactericidal control of acid formation is described, along with two new inexpensive methods to treat acid mine water. These papers were prepared for an acid mine drainage technology transfer meeting held in Pittsburgh, PA, on April 3 and 4, 1985. INTRODUCTIONAcid drainage from coal mines is one of the most persistent industrial pollution problems in the United States. Over 5,000 miles of streams and rivers are adversely affected, primarily by underground mines that have been abandoned for decades. Meanwhile, at active mining operations and at sites where mining occurred after 1977, discharge water must be treated to meet fairly stringent regulatory limits--at a cost to the industry of over $1 million per day.The Bureau of Mines has a special responsibility to facilitate integration of mining and mineral processing with environmental safeguards. This responsibility is twofold: the development of techniques to reduce or eliminate environmental degradation, and the improvement of existing pollution control processes to make them more efficient and more cost effective. Research in acid mine drainage exemplifies the Bureau's concern for these environmental aspects of mining.This collection of papers summarizes much of the Bureau's recent research on acid mine drainage and will give the reader a sense of where the research is headed, in addition to providing details regarding new technology and recently acquired knowledge. The research papers address four basic objectives:"

Jan 1, 1985

By V. A. Melezhik, P. K. Skufin, L. P. Nilsson

these factors into account. Theoretical and

Aug 1, 1994

By G. K. Derby

Five different types of drilling systems were developed under the flexible drill program that was initiated by the Federal Bureau of Mines to protect roof bolter operators. The systems were designed for underground coal mines with seams as low as 30 inches, and with roof bolts longer than the height of the seam opening. Four of the developed systems were true flexible drills; the fifth was a remote-controlled, automatic rod changer concept. Only two of the five firms successfully completed testing requirements under the original contracts: BendixCorp.,4 with a true-flex drill; and Ingersoll-Rand Research, Inc., with the rod changer concept. The Bendix drill was rated best, and the Ingersoll-Rand drill was rated second. Because of the closeness of the ratings and the vast differences in the two development concepts, both systems had sufficient potential to justify further development funding for design updating and testing. Also, both systems warranted consideration for inclusion into other ongoing development projects under both safety and energy directed programs.

Jan 1, 1978

By C Noble, J Webster-Brown

A survey of selected West Coast Streams was undertaken in Summer 2001, Summer 2002 and Winter 2002 to establish the degree of arsenic (As) contamination in waters and sediments downstream of old coal and gold mine workings on the West Coast. Of the catchments studied, Soldiers/Ford Creek and Rapid Stream showed the most significant elevated As concentrations, predominantly in dissolved form, and evidence of AMD or ARD contamination (high sulfate concentrations and/or acidity). The rate and processes of removal of dissolved arsenic from the water column (attenuation) have been studied in these catchments. The Rapid Stream and Soldiers/Ford Creek catchments are directly affected by adit drainage from the Sullivan and Blackball coal mines respectively. Both catchments have high As concentrations in the sediments, with up to 770 mg/kg in Soldiers Creek and 490 mg/kg in Rapid Stream. Dissolved As concentrations are significantly elevated in the neutral pH waters of Soldiers Creek; typically as high as 100 - 200 ¦g/kg, up to 500 m downstream of the main adit discharge (800 ¦g/kg As). Adit inflows to Rapid Stream were acidic and contained 20 - 30 ¦g/kg dissolved As, with relatively high concentrations of arsenic in the stream water in winter (up to 18 ¦g/kg), but not in summer. Analysis of concentration trends and As:SO4 ratios downstream of these obvious As sources confirmed that dissolved As had been actively removed from the water column, but varied seasonally with greater removal evident in summer. Adsorption of arsenic onto iron oxide in the stream sediments is the most likely mechanism of removal. The Snowy River catchment, on the other hand, has relatively high As concentrations in both the sediments and the water column, but there was little evidence of a distinct AMD or ARD input from the Blackwater gold mining area. Preliminary investigation suggests that dilution rather than attenuation is responsible for decreasing As concentrations downstream.

Jan 1, 2003

By Natalie J. Shackleton, Deryck de Vaux, Cyril T. O’Connor, Vratislav Malysiak

"The major losses of PGM and base metals in the beneficiation of platinum group deposits occur during the separation of gangue from the value minerals by selective flotation. A number of studies have shown that this negative impact on flotation is due to surface passivation, caused by various ions that may originate from the external water supply or, as is likely in the majority of cases, from the oxidation of the mineral surfaces and the grinding media. The objective of the study was to investigate the effect surface passivation and inadvertent activation have on flotation and how this can be managed so as to increase the separation of pentlandite and pyroxene. The aim was to minimise the percentage pyroxene reporting to the concentrate and simultaneously maximise the pentlandite recovery. The testwork incorporates the addition of an activator (copper sulphate), a complexing agent, such as DETA (diethylenetriamine) and a dispersant (polyphosphate) at pH 6 and pH 9 in an attempt to alleviate the surface passivation of pentlandite and inadvertent activation of pyroxene. Both synthetic minerals and plant ores were studied in order to determine the effect surface passivation and inadvertent activation have on mineral surface alteration and floatability. Zeta potential determinations, microflotation, ToF-SIMS (Time of Flight Secondary Ion Mass Spectrometry) analyses, laboratory batch flotation tests and continuous flotation testwork were used as tools to study the surface alteration and/or floatability.Zeta potential determinations and ToF-SIMS analyses showed that copper adsorption is non-selective. Both pentlandite and pyroxene become copper (II)-activated in the presence of copper sulphate and subsequently, in the presence of xanthate, adsorption of the collector will occur onto copper activated mineral surfaces. Zeta potential determinations also showed an alteration of the surface charge in the presence of polyphosphate, thereby inhibiting surface passivation of sulphides by slime coatings due to surface repulsion."

Jan 1, 2003

By Norman Disley, David B. Counter, Lionel Hebert

Misfires in underground and surface production blasts can be costly. Costs can arise from loss of resource, production interruptions, having to redrill or otherwise refire the blast (a hazardous process at best), due to added secondary blasting or breakage, and/or from increased LHD maintenance costs attributable to poor fragmentation.

Jan 1, 1996

The mining industry continues to experience a skills shortage and this is having an impact on the ability of mining companies to operate sustainably. Apart from a few exceptions, there is a dearth of geologists, mining engineers, metallurgists as well as environmental scientists and other professionals in the global mining industry. This relates to both quantity and quality. It makes good business sense for mining companies to employ local professionals rather than expensive expatriate staff. In some cases a mining company could employ more than 10 local mining engineers for the cost of one expatriate. However, in many countries local professionals are not always equipped professionally to work on mine sites. The result is that many companies are not operated optimally due to human resources gaps. In some cases, particularly in key areas such as mine planning, this threatens the sustainability of the operation or at the very least results in sub-optimal resource utilisation. This paper briefly presents some of the issues and strategies being implemented and that might be implemented to maintain a sustainable supply of quality minerals graduates to the industry in 2011 and beyond.

Jan 1, 2011

By Carl Johnson, D. R. Todd

The Blue Ridge Low Level Outlet (LLO) was a design/build contract to provide a secondary means of discharging water from the Blue Ridge Reservoir. The project involved driving a 3.25 m (11 ft) modified horseshoe tunnel by 293.5 m (963 ft) long utilizing conventional drill and blast methodology. The intake shaft and structure were constructed inside of a sheet pile cofferdam surrounded by a maximum of 20.1 m (66 ft) of water. The shaft was excavated 4.87 m(16 ft) diameter to a depth of 12.8 m (42 ft) below the tremie slab elevation. Steel lining, including a transition from 3.66 m to 2.74 m (12 to 9 ft) diameter and a90 degree elbow were installed in the inlet shaft and then backfilled with concrete. This paper will describe the RFP phase, the design phase, challenges of the underground construction and contractual challenges.

Jan 1, 2005

By David Oyler

Sonic travel time logging of exploration boreholes is routinely used in Australia to obtain estimates of coal mine roof rock strength. Because sonic velocity logs are relatively inexpensive and easy to obtain during exploration, the technique has provided Australian underground coal mines with an abundance of strength data for use in all aspects of ground control design. However, the technique depends upon reliable correlations between the unconfined compressive strength (UCS) and the sonic velocity. This paper describes research recently conducted by the National Institute for Occupational Safety and Health (NIOSH) aimed at developing a correlation for use by the U.S. mining industry. At three coreholes in Illinois, Pennsylvania, and southern West Virginia, sonic velocity logs were compared with point load tests for a broad range of coal measure rock types. For the entire data set, the relationship between UCS and sonic travel time is expressed by the following equation, where UCS is in psi and t is the travel time of the P-wave in microsec/ft. UCS = 468,000 x e-0.054t (1) The r-squared value for this equation is 0.87, indicating that a strong correlation between sonic travel time and UCS can be achieved with this technique. The paper also addresses the steps that are necessary to ensure that high-quality sonic logs are obtained for use in estimating UCS.

Jan 1, 2008

By G. Huang, S. Vytla

Computational fluid dynamics (CFD) is a continually developing numerical technique by which complex fluid flow problems can be solved on computers. To be able to transfer CFD expertise to analyze and design a face-ventilation system, a comprehensive validation study of current CFD tools against mining-related benchmark experiments is required. In the last four years, such studies, funded by National In¬stitute for Occupational Safety and Health (NIOSH) under Grant #R01 CCR415822, were conducted in the Department of Mining Engineering at the University of Kentucky. A wide array of ventilation schemes and mining configurations were considered. Recently, an additional study was performed in cooperation with the NIOSH Pittsburgh Research Laboratory. This study was dedicated to the methane behavior in the empty (containing no equipment) face area with a blowing curtain and a 10. 7-m (35-ft) setback. In this paper, the authors present and discuss the computer-simulation data and compare them with data collected during the laboratory studies at the NIOSH lab.

The Greymouth Coal field is situated on the West Coast of New Zealand's South Island and has been mined for coal for more than 120 years. The area covered in this paper is within the Rapahoe Sector of this field and contains >200 million tonnes of low ash, low sulphur, bituminous rank coal. Paper No 6, presented to the 19th Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy in Christchurch in August 1985 by R G Bowman, explained 'A Geologist's View' of the 'Economic Potential of the Greymouth Coalfield', and describes previous geological assessments of the Rapahoe Sector.

Jan 1, 1989

By F. R. Lee

When the Bureau of Mines was established in July 1910, one of the problems immediately attacked by the new organization was the development of standard, for the design and testing of electrical equipment that could be used without fear of initiating fires and explosions in underground coal mines. Research and investigation by Bureau personnel, supplemented by the published results of similar work by European mining authorities, led to the establishment of standards or "schedules." which guide manufacturers ill the design of many types of electrically operated machines and devices used in underground coal Mining. By issuing these standards, Bureau personnel establish the requirements to be met by such equipment before it tan be approved by the Bureau of Mines as permissible for use in gassy coal mines. Every 2 years the Bureau of Mines publishes a list of equipment that leas been accepted as approved or permissible during the preceding 2 calendar years. This is done to inform the mining industry of the availability y of the latest equip¬ment for safe use underground.

Jan 1, 1964

By F. R. Lee

[WHEN the Bureau of Mines was established in July 1910, one of the problems immediately attacked by the new organization was the development of standard, for the design and testing of electrical equipment that could be used without fear of initiating fires and explosions in underground coal mules. Research and investigation by Bureau personnel, supplemented by the published results of similar work by European mining authorities, led to the establishment of standards or "schedules." which guide manufacturers in the design of many types of electrically operated machines and devices used in. underground coal Mining. By issuing these standards, Bureau personnel establish the requirements to be met by such equipment before it tan be approved by the Bureau of Mines as permissible for use in gassy coal mines. Every 2 years the Bureau of Mines publishes a list of equipment that leas been accepted as approved or permissible during the preceding 2 calendar years. This is done to inform the mining industry of the availability of the latest equipment for safe use underground.]

Jan 1, 1964

By Frederick Laist

AFTER a series of experiments covering a period of about three years, ending from the spring of 19iJ.2 to the spring of 1915, a 2,000-ton leaching plant for the treatment of the accumulated copper concentrator tailing was built and put into operation. During the experimental period, the first step was that of laboratory experiments or beaker leaches. The results on this small scale were so satisfactory that a small operating plant, capable of handling 5 tons of roasted tailing per day, was installed. Again, the results proved satisfactory and an 80­ton plant was built and operated continuously from August until February, 1913. In this plant, full-sized roasting and leaching units were

Jan 8, 1916