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By David Corke

The paper presents the development of Federation of Piling Specialists (FPS) calculation of rig track loading, the production of the Building Research Establishment document “Working platforms for tracked plant” (BR 470), working platform testing and considerations of rig stability. The paper also discusses the importance of rigorous and well documented procedures and proposed future development of rapid working platform testing methods. Topics presented include the fundamental requirements and principles involved in the testing, design and maintenance of working platforms, rig track loading, the BRE design method and site testing analysis. The paper stresses the need for testing and design processes to be robust and simple and quick to perform as there is often little time between the award of a contract and the need to start work on site. Also, it is vital that all aspects of working platform design can be carried out with information that is available to the platform designer. Developments in the UK over the last two decades have resulted in improved quality and safety of working platforms that will hopefully be further enhanced as design and testing methods continue to improve.

May 1, 2022

By D Caley

During the response to the Moura No 4 disaster, use was made of the New South Wales Mines Rescue Service’s ‘Mineshield’ inertisation equipment. The equipment had to be transported from Newcastle, approximately 1400 kms, and the liquid nitrogen a similar distance. The time taken, and therefore availability of the liquid nitrogen, became a significant problem. Operational issues were also experienced during use. Typically the liquid nitrogen is converted to a gas (vaporised) before being injected into the mine. However, as the propane gas tanker used for the vapourising unit was delayed, an attempt was made to inject the liquid nitrogen directly down uncased boreholes. This proved unsuccessful.Following the Moura No 4 disaster and the Moura No 2 disaster, recommendations were made relating to having inertisation capacity for the Queensland coal mining industry. Today the Queensland industry has multiple options available for inertisation, including the high-volume GAG and smaller volume units such as boilers and membrane separation units. Although it ultimately aided re-entry into Moura No 4, most likely due to the issues associated with supply to Central Queensland, liquid nitrogen has not found favour within the Queensland industry as an inertisation tool.Coregas has commissioned an air separation plant in Mackay, improving the availability of liquid nitrogen to Central Queensland. Based on the availability of this nitrogen, recent sealing operations at Kestrel have trialled using liquid nitrogen and associated vapourising units. This paper details the practical application and findings of using liquid nitrogen during routine longwall panel sealing.CITATION:Caley, D, 2017. Using liquid nitrogen for the inertisation of goafs, in Proceedings Australian Mine Vent Conference 2017, pp 35–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Electrochemistry Measurement, Using Chena Analyser, to Investigate Selective Separation of Pentlandite and Pyrrhotite

Sep 13, 2010

By E Villaescusa, C Drover

Fully resin encapsulated threaded bar and cement grouted cable bolts are common forms of reinforcement for underground mining excavations constructed at great depth. These elements are frequently installed to dissipate the dynamic loads caused by violent rock mass failure mechanisms. Failure of the ground support scheme without rupture of the reinforcement elements implies that the maximum energy dissipation capacity of the scheme was not utilised. The ground support damage mechanisms are useful to identify in this context as they reveal vulnerabilities which limit the scheme performance. This paper presents a number of field observations of reinforcement performance following a range of dynamic loading conditions. It was observed that fully resin encapsulated threaded bars exhibit variable behaviour. In particular, inconsistent resin encapsulation was frequently observed in combination with surface support failure, indicating that the retention function of these elements may allow preferential loading of the surface support system. Observations of cement grouted, twin-strand plain cable bolts reveal a common mode of damage involving differential displacement across the steel-grout interface and slip of the cable within the borehole. This is common where strands are not mutually tensioned with barrel and wedge assemblies. Surface fixtures that exceed the strength capacity of the cable strand are required in order to minimise the occurrence of this response. Improved load transfer from the rock mass and surface support to the cable can thus be achieved, particularly where small block size failure occurs.CITATION:Drover, C and Villaescusa, E, 2016. Field performance of fully encapsulated reinforcement during violent failure events, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 659–668 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By S. C. Radopoulou

Pavement condition assessment is an indispensable constituent in maintaining roadway infrastructure. Current practices for pavement condition assessment are labor intensive which introduce subjectivity in pavement rating and are time consuming. Automated methods rely on full 3D reconstruction of the pavement surface which introduces high equipment and computation costs. This paper presents a methodology for detection of patch type distresses in asphalt pavement images. This method uses filtering and histogram equalization for clearing and enhancing the image accordingly. It continues by applying the morphological process of closing, along with some rules based on the characteristics of a patch when captured in an image, to finally detect the area it occupies. Criteria for area, length, and width of a patch as seen in an image are taken into account to decide whether a probable patch is actually a patch. The method has been implemented in C#. The preliminary experiments demonstrate it produces promising recognition results

Aug 1, 2013

This paper is intended partly as a summary of the conclusions that have been arrived at by various authorities on this matter, and also with a view to initiate some discussion on the subject, especially as most of the quartz gold mines in Victoria are operated without having any proper assay plans or any idea of the real values other than those given by the mining managers, who, from experience in the particular cases, are supposed to be able to arrive at a correct idea of the true values of- the ore, and, in many cases, oppose any other methods than their own, holding the view that no sampling is equal in correctness to the bulk sample of the battery. The necessity of properly sampling and estimating the ore in a mine in every case, perhaps hardly needs to be urged on the members of the Institute, but is not, apparently, so obvious to others.It is proposed to confine this paper to the sampling of ore reserves in a mine, and the various points which have to be taken into consideration in arriving at values, from the assayer's point of view, leaving the methods of sampling metallurgical products out of consideration for the present. "It is advisable to define" ore reserves" as ore exposed on three sides at least, and accessible to the sampler on all three. "Prospective ore" would include all ore not so fully exposed; but which may, from the nature of the case, and the geological conditions prevailing, be reasonably supposed to exist.

Jan 1, 1904

By Nick D. Rose

The Dy deposit is a 21 Mt Pb-Zn-Ag-Au SEDEX-type massive sulphide resource located in the Anvil District, Faro, Yukon. This relatively unexplored orebody lies at a depth of 480 to 920m below surface, dips 20 to 35o and comprises vertical ore thicknesses of 3 to 28m at a 9% Pb + Zn cut-off grade. The deposit has been tested at depth with 63 surface diamond drillholes, but has not yet been explored or developed by underground means. Over the past decade, pre-feasibility investigations were conducted for two separate owners of the property to determine the economic viability of developing an underground mine at Dy. Following these previous studies an assessment was undertaken between 1998 and 2000 to further investigate geotechnical considerations for underground mining. The results and conclusions drawn from this study provide direction for possible future exploration at Dy.

May 1, 2002

By M. Maccagni, J. Nielsen

"Engitec developed the EZINEX® Technology some years ago to recover zinc from oxidized secondary sources. This process works at neutral pH and can take into solution any kind of metal, but iron is rejected and remains in the leach residue. Engitec has also developed the FLUOBORATE System, which is able to recover lead and copper from relevant concentrates. Some iron is leached into solution, but it is controlled through a solution purification bleed treatment. In this paper, we present the two above mentioned technologies. They are very different with regards to the chemical environments and the methods used to control the build-up of iron in solution, but both systems are suitable to treat iron bearing feeds.INTRODUCTIONIn the design of hydrometallurgical processes, the most important issues are the water balance, the filtration and the control of impurities. This is particularly important when the process includes an electrowinning unit. Iron has been one of the most problematic elements to remove, especially in acidic environments.Engitec Technologies has developed several hydrometallurgical processes divided in two different electrolyte lines: the Fluoborate Technology for the recovery of lead and copper from primary and secondary sources and the Ammonium Chloride System based on a chloride electrolyte for the recovery of different non-ferrous metals, among which zinc and lead are the most important. In both cases, iron is present in the feed and needs to be eliminated from the solution. It is not a problem for the quality of the metal produced, but when present in solution, it consumes the basic electrolyte reducing its free concentration which is very important both for both the leaching and electrowinning unit operations. Both process systems are very peculiar, the fluoborate case being much more intriguing."

Jan 1, 2016

By G. W. Jones

The results presented in this report deal with the elimination of explosion hazards of ether-oxygen mixtures by the addition of helium. The method is based upon the fact that every combustible gas, vapor, or dust will not burn or explode when the oxygen content of the mixture is reduced below certain definite values. These critical oxygen values are usually different for each combustible, varying with the percentage of the combustible present in the mixture and also with the inert gaseous material used to reduce the oxygen content of the mixture.

Jan 1, 1941

By S. S. Peng, C. T. Holland

Mountain Top Removal (MTR) mining started in West Virginia nearly thirty years ago. This surface mining method can extract multiple coal seams as thin as a few inches thick with total recovery and minimum rock dilution in very steep mountainous terrain. It is highly efficient even if coal seams are in close proximity and small in aerial extent. Consequently, MTR has been widely used in the Central Appalachian Coalfield (mainly Kentucky, Tennessee, Virginia and West Virginia) for the past thirty years with great success. In that respect, there has been no demand for research and little scientific research has been performed to investigate its impacts on the surroundings in the history of MTR mining. However, in the past two years the debate over the MTR mining has grown quickly and in times become very intensely. This paper describes chronologically the issues raised by various parties, legal actions, its impacts on mining permit application and research projects developed to address the issues.

Jan 1, 2000

By D. Schleiss

Reduced access to knowledgeable workers is creating challenges for operations. We are doing more 4D Operations - dirty, dull, dangerous, and distant. Personnel costs in these environments are high, and it is not always possible to get the people where you need them. Integrated Operations is a strategy to integrate people, process, and technology for faster and better decision making. Adopting an integrated operations approach can help to relocate personnel, improve collaboration, and align objectives to deliver reduced costs and improved performance. In this paper, the authors will highlight the required infrastructure to enable an Integrated Operations platform. Key decision points for enabling this technology for both Greenfield projects and existing mines will be discussed. Furthermore, the benefits and improved return on investment that result from deployment of an Integrated Operations strategy will be presented.

Jan 1, 2014

By G. W. Jones

The results presented in this report deal with the elimination of explosion hazards of ether-oxygen mixtures by the addition of helium. The method is based upon the fact that every combustible gas, vapor, or dust will not burn or explode when the oxygen content of the mixture is reduced below certain definite values. These critical oxygen values are usually different for each combustible, varying with the percentage of the combustible present in the mixture and also with the inert gaseous material used to reduce the oxygen content of the mixture.

Jan 1, 1941

By Ron Bromenschenkel

The State of California, Department of Transportation is currently retrofitting a major interchange near the San Francisco area. The project is located in a highly traveled area of Oakland with light rail commuter service near many footings. Over 600 micropiles are being used in conjunction with CIDH piles for footing stabilization. A specially designed Soil Nail pile will support footings for a new light rail utility structure. Pile testing features in this contract serve as points of interest for future foundation designs. The presentation focuses on substructure issues of this incterchange retrofit. Both design and construction considerations will be covered. Design Considerations: ? Project Description ? Structure inadequacies ? Design criteria ? Design contraints ? Retrofit strategy ? Consultant analysis ? Pile Designs and Test Sites ? Contract Specifications ? Construction Plan and Cost

Jan 1, 1998

By B. Arjang

ABSTRACT: Ground stresses are one of the significant factors in the context of rockbursts and underground instability at some hard rock mines in Canada. Overcoring strain relief measurements using triaxiaI strain eel is were performed at depths between 60 to 1890 m at several mine sites to provide stress data for stability analysis and optimum mine design. Pre-mining ground stress determinations from 64 stress tensor analyses resulted in the following average stress gradients: Maximum horizontal stress. -Hmax - 8.18 - 0.0122 MPa/m depth Minimum horizontal stress. _-,,min - 3.64 - 0.0276 MPa/m depth Average horizontal stress. -11, 5.91 - 0.03-19 MPs m depth Vertical stress. '-, - 0.0266 - 0.008 MPa/m depth The maximum and minimum horizontal compressive stresses. with an average ratio of 1.75 ,0..45. prevail in east--west and northerly directions. respectively. Horizontal compressive stresses in excess of vertical overburden load were determined. indicating large variations in ratios to a depth of about 1000 m with decreasing trend towards depth. From present data. a particular regional zoning for the magnitude and direction of horizontal stress fields cannot be outlined. A common feature at mines with near vertical orebodies is that the maximum horizontal compressive stress acts perpendicular to strike while the minimum horizontal compressive stress is aligned on-strike. The vertical stress components approach the gravitational overburden load.

Jan 1, 1989

Shortly after Denny, Robson, and Irwin published their first paper in 1937, on the prevention of silicosis by metallic aluminium, experiments were begun on the practical application of the discovery.It was thought at that time that aluminium powder, to be effective in aluminium therapy, would have to be intimately admixed with siliceous dust at the latter's source. There followed several years of experimental work underground, during which the application of aluminium powder was tested in:(1) Speakers on machine columns, vibrated by drills.(2) Vials placed in drill holes to be blasted.(3) Both homogeneous and heterogeneous mixture with explosives.(4) Packages with tamping.(5) Compressed-air lines.(6) Special compressed-air ejectors for use while drilling and after blasting.(7) The discharge of ventilation fans.(8) The filters of respirators.It was concluded from this research that any adequate method of introducing aluminium powder into a mine atmosphere would require too much extra gear, supervision, and aluminium p;wder, and would interfere unduly with underground routine.Later, animal experiments by Denny, Robson, and Irwin2 showed that aluminium powder provided effective therapy when inhaled independent of silica dust. Therefore, some means of surface treatment was deemed more practical.APPARATUS USED IN THE DEVELOPMENT OF ALUMINIUM PROPHYLAXIS SAMPLINGA basic requirement was a method of sampling to assess accurately the particle-size concentrations of dispersed aluminium powder. Konimetry, though regularly practised at McIrityre, was inadequate for the research in mind. On the other hand, the efficiency of the thermal precipitator was recognized as being very high. Accordingly, the latter instrument was chosen as best suited to our needs. Through the courtesy of the Ontario...

Jan 1, 1945

By J. Moore, D. Gault, R. V. Lugn

Impact of small projectiles with velocities between 0.9 and 7.3 km per sec on basalt produce craters chiefly by the ejection of fragments. Weight-size distributions of the ejecta are linear for part of the size range of the fragments. Cumulative weight-size distributions of the ejecta from different craters vary because of erratic formation of large fragments and a large percentage of ejecta below 0.1 mm. In the range of velocities studied, the crater depth is approximately proportional to the 0.75 power of velocity of the projectile. This relationship may represent a transition regime between the fluid impact regime and the undeformed projectile impact regime. The volumes per unit of projectile energy of the craters produced are comparable to those reported for lower speed projectile impact and drill bits. An experimental investigation of projectile impact on rock is being conducted jointly by the Ames Research Center of the National Aeronautics and Space Administration and the U.S. Geological Survey. Projectiles are launched with light-gas guns at the Ballistics Range of the Ames Research Center. The craters and ejecta produced in these experiments are being studied by the U.S. Geological Survey. Steel, aluminum and polyethylene projectiles weighing from 0.25 to 0.015 g were accelerated to velocities of 0.88 km per sec (2,900 fps) to 7.3 km per sec (24,000 fps) with a light-gas gun, using hydrogen as the propellant medium. Projectiles impacted the targets normal to plane rock surfaces in an atmosphere of air with a nominal pressure of 25 to 50 mm of mercury. The metal projectiles were mounted in supporting four-piece nylon sabots, which guided the projectiles down the launching tube. After launch, aerodynamic drag acted to separate the sabots from the projectiles. Impact velocities were determined with time measurements and spark photographs of the projectiles in flight. Ejecta were collected in lucite and aluminum containers placed around the target block. A small hole in the containers permitted projectile entry. Impact of projectiles of the size employed produced craters in the rock targets chiefly by ejection of fragments. The craters are small, roughly conical depressions with crushed and intensely fractured rock at the bottoms of the depressions. The ejecta are composed of pieces of the projectile and rock fragments ranging in size from a few tenths of a micron or less to several centimeters in maximum dimension. In this paper, the structural features of the craters, the weight-size distributions of the recovered ejecta, and crater depth and crater volume relationships are described. DESCRIPTION OF CRATERS Typical craters (Fig. 1) produced by experimental projectile impact in basalt are shallow, wide base

Jan 1, 1963

By E. C. Westman, W. R. Thomas, W. J. Conrad, A. J. R. Russell

"Understanding ground control problems continues to remain a focus of the mining engineering community. To aid mine operators and engineers in identifying and responding to ground control issues, the Ground Observation System (GOS) is being developed. The GOS is an integrated, web-based graphical user interface that displays ground response data collected wirelessly from an underground mine. It presents data in an intuitive manner to assist mine personnel, who are on- or off-site, in quickly identifying hazardous areas. Geotechnical instrumentation will be connected to wireless transmitters that will relay data in real-time to a surface computer that stores the information in a database. The GOS website will then display the geotechnical data in graphical and tabular forms, as well as in conditionally formatted mine maps. Data from each measurement device will be able to be viewed in its entirety or within a time interval, and can be downloaded for further analysis. The ability of the GOS to quickly interpret and communicate mine hazards to personnel of varying technical ability should prove to be a useful tool in understanding ground control and thus improving mine safety.INTRODUCTION Computer-based data information centers that convey operating parameters and conditions are prevalent in modern underground mines. Today’s systems are popular in showing ventilation controls and monitoring equipment performance (Jyothi & Meena 2013). In ground control monitoring, Conover, Ross, and Bigby, 2010 have installed a wired telltale roof monitoring system that sends roof displacement data every ten minutes to a computer on the surface. The computer receives, stores, and displays the data in real time. Data can also be viewed remotely through a password protected internet connection. Additionally, an internet connection allowed for remote updates to the system which streamlined software development and maintenance by eliminating travel (Conover et al., 2010). Currently, no such system beyond Conover et al.’s design has been accomplished. The Ground Observation System (GOS) is being developed to fill the void of real-time geotechnical monitoring in underground mines. A wide array of data will be transmitted wirelessly and broadcasted to on- and off-site mine personnel through the internet. The GOS will incorporate geotechnical data from roof deformation, borehole scratch testing, photogrammetry, and seismic monitoring into one interface, all while achieving permissibility for the use in gaseous mines. As a result, a comprehensive view of rock movement due to mining will be available. The overall purpose of the GOS is to deliver warnings; to ensure reliable data is relayed to personnel for the identification of potential ground failures, provide mine engineers information to design more stable mines, and assist with further geotechnical research."

Jan 1, 2015

By J. Wagner, P. Eger, G. Melchert

In 1991, LTV Steel Mining Company decided to close an open pit taconite mine in northeastern Minnesota, using a passive treatment approach consisting of limiting infiltration into the stockpiles and wetland treatment to remove metals. Over 50 million metric tons of sulfide-containing waste had been stockpiled adjacent to the mine during its 30 years of operation. Drainage from the stockpiles contained elevated levels of copper, nickel, cobalt and zinc. Nickel is the major trace metal in the drainages, and prior to closure annual median concentrations ranged from 1.5-50 mg/L. Copper, cobalt and zinc are also present but are generally less than 5% of the nickel values. Median pH ranges from 5.0 to 7.5, but most of the stockpile drainages have pH greater than 6.5. Based on the chemical composition of each stockpile, a cover material was selected. The higher the potential a stockpile had to produce acid drainage, the lower the permeability of the capping material required. Covers ranged from overburden soil removed at the mine to a flexible plastic liner. Predictions of the reduction in infiltration ranged from 40% for the native soil to over 90% for the plastic liner. Five constructed wetlands have been installed since 1992, and have removed 60-90% of the nickel in the drainages. Total capital costs for all the infiltration reduction and wetlands exceeded $6.5 million, but maintenance costs are less than 1% of those for an active treatment plant. Since mine drainage problems can continue for over a hundred years, the lower annual operating costs should pay for the construction of the wetland treatment systems within seven years.

Jan 1, 1999

By Theodore L. Turner

This Bureau of Mines report describes calcination of kaolinitic clay in a direct-fired 2-1/2- by 24-ft rotary kiln at 750° and 775° C. Methods for preparing kaolin feed materials and characterization of calcined products are discussed. Approximately 99 pct of the alumina in a typical eastern Georgia kaolin was soluble in HC1 after calcination at either 750° or 775° C.

Jan 1, 1982

By E. S. Shedd

Amenability studies were conducted by the Federal Bureau of Mines on an electrooxidation technique for the extraction of mercury from cinnabar ores, particularly those that are too low in grade to be furnaced or retorted economically. Oxidation was accomplished by electrolysis of the ore while slurried with brine. Mercury was dissolved through the formation of the soluble tetrachloro mercury complex, HgC142-. Mercury extractions ranged from 90 to 98 percent in 4 to 6 hours of processing time when tests were made on eight different types of cinnabar ores containing from 0.7 to 18 pounds mercury per ton ore. Salt concentration was varied from 4 to 10 weight-percent depending on whether Pb02 anodes and iron cathodes were used or whether graphite was used for both electrodes. Power consumption ranged from 17 to 64 kilowatt-hours per ton of ore treated. Ninety-nine percent of the mercury was recovered from pregnant solutions by precipitation on an active metal such as zinc, followed by distillation of the resulting amalgam at 600° C.

Jan 1, 1975