Search Documents

By J M. Galvin, B J. McKinnon

Lightning Ridge, Australia, is the largest opal producing area in the world. Most opal is mined from shallow underground mines by individuals or small partnerships with the industry having been protected from large-scale development to date. The safety performance of opal mining has lagged both general mining industry standards and community expectations. The application of geotechnical analysis to the opal fields has the potential to considerably reduce injuries and fatalities. With consideration of the local culture, preliminary geotechnical analysis has been applied to some current methods of work utilised at Lightning Ridge. Practical solutions have been advocated and are presented in this paper. Improvements to safety generated by these practical solutions indicate that further geotechnical research at Lightning Ridge is warranted and would be beneficial.

Jan 1, 2002

"This paper reviews the chemistry involved in the recovery of gold from cyanide solution with anion-exchange resins, and also discusses the most critical aspects of the engineering of an effective resin-in-pulp (RIP) process. As far as the chemistry is concerned, the conclusions reached by a great many researchers, as well as the performance of the only operating RIP plant in the Western World, at the Golden Jubilee Mine in South Africa, support the view that the process is technically viable and, in many cases, could prove to be more attractive economically than alternative processes such as zinc cementation and carbon-in-pulp (CIP). On the engineering side, there is still a need for further development before larger scale ( > 50,000 tpm) RIP plants can be designed, built and operated with confidence. However, the experiences gained during nearly 3 years of operation of the Golden Jublee RIP plant indicate that the process can be engineered with confidence for smaller operations ( < 50,000 tpm), and this will probably be the scope of application of the first-generation RIP plants. INTRODUCTIONThe use of anion-exchange resins in gold processing has, for a number of years, been proposed as an alternative to more conventional processes such as zinc cementation and carbon adsorption, and detailed research programs that have been carried out at a number of laboratories have demonstrated the technical viability of the process. (Burstall et al, 1953, Davison et al., 1960, Tataru, 1973, Laskorin et al. 1978, Hosking, 1984, Riveros and Cooper, 1987 and Palmer et al., 1988)The main incentive for this work was the fact that resins have several characteristics that are quite different from carbon, which make them potentially more attractive substrates for the recovery of gold. The following are examples: -"

Jan 1, 1991

A South African gold mining rock-related fatal accident database has been analysed in order to determine rock-related fatality trends in the gold mining industry over the period 1990 to 1998. This analysis was extended further to include some of the individual reefs mined and focused particularly on the Carbon Leader Reef, the Ventersdorp Contact Reef, the Vaal Reef and the Basal Reef. Rock-related accident locations are also presented. A stope rock-related risk is proposed, where the fatality rate in terms of rock-related fatalities per million square metres mined for the gold mining industry as a whole is compared to individual reefs, allowing a stope rock-related risk to be attributed to the individual reef. This comparison is extended further by removing the contribution by the reef being evaluated from the industry data, thereby allowing this reef to be directly compared to the rest of the industry with respect to a stope rock-related risk.

Jan 1, 2001

By Pakalnis Rimas, Lyndon Clark, Tom Brady

A major focus of ground control research presently being conducted by the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) is to incorporate data on weak rock masses into existing design relationships, with an emphasis on updating the span design curve for manned entries and the overbreak curve for longhole entries. Both curves were originally developed at the University of British Columbia, Vancouver, BC. The original database has been augmented by information from mines throughout the United States, Canada, Australia, and Europe. The common factor in all these mines is the presence of a weak back and/or walls. In most cases, the ore zone is the weakest rock unit and must be stabilized so that the mineral-bearing rock can be extracted safety. The current NIOSH research attempts to provide rock mechanics tools to assist a mine operator in making economic decisions that will also ensure a safe working environment. This paper documents the Nevada database with a special emphasis on Nevada underground gold mines.

By Hongfei Li, JianLong Wang

This paper introduces the technical characteristics, transformation scheme and production practice of the project in which Copper P-S Converter was replaced by Bottom Blowing Continuous converting for the first time, and introduces the technical achievements obtained by the project. The application practice proves that bottom blowing copper continuous converting technology can completely solve the problems of fugitive off-gas pollution in the ladle transportation, large amount of flue gas and fluctuation of flue gas caused by P-S converting. Comprehensive energy consumption and operating costs of producing blister copper, safety and environmental risks are greatly reduced, and economic, environmental and social benefits are significant. It is one of the preferred technologies for upgrade and to replace P-S converting technology. INTRODUCTION At present, more than 80% of copper production capacity is still using the P-S converting technology with a history of more than 100 years. During P-S converting process, melted copper matte needs to be transported by ladle, and it needs to rotate the furnace body several times, causing a lot of serious environmental and safety risks such as SO2 flue gas emission and low-altitude SO2 pollution. In addition, the high operating cost caused by low rate of air blowing, the short life of the refractory materials and high energy consumption during P-S converting become big problems. Other problems such as large amount of flue gas, low SO2 concentration, large fluctuation of flue gas volume and SO2 concentration, and discontinuous flue gas cause high cost of subsequent flue gas treatment are also needing to be solved. In order to solve these problems during the P-S converting, metallurgical engineer in various countries has spared a lot of efforts to develop continuous blowing process for decades. The continuous converting that have been industrially applied are flash continuous converting, Mitsubishi continuous converting, Noranda continuous converting, Bottom Blowing Continuous converting and multi-lance top blowing continuous converting

Jan 1, 2019

By Dipak C. Talapatra

This report describes the development of guidelines for design, inspection and maintenance of automatic couplers. In order to devise the guidelines, performance requirements for automatic couplers were carefully established. This was clone through a comprehensive survey of coupler manufacturers and extensive observation of automatic couplers in service in a broad spectrum of mines. The capability of the couplers to withstand the demands of the mining environment in terms of strength characteristics, gathering range, curve negotiability, and other factors were all carefully evaluated. An analysis of coupler related accidents for the years 1972-1976 was carried out to provide information on the safety and reliability of existing automatic couplers. This formed an important input to the development of the guidelines. It is expected that these guidelines will he useful to coupler manufacturers for establishing designs for improved automatic couplers, and to mine operators for maintaining their couplers in a safe and good operating condition throughout their expected lifetimes. This report is in two volumes: Volume l - Technical Report Volume 2 - Design, Inspection, and Maintenance Manual

Jan 1, 1977

By Sergio N. Monteiro

Natural lignocellulosic fibers are successfully replacing synthetic fibers in many engineering applications. In addition to well-known conventional lignocellulosic fibers, others with promising properties are now being considered. The present work investigated the mechanical and structural characteristics of a relatively high strength fiber, curaua (Ananas erectifolius) from the Amazon region of Brazil. The results obtained from tensile tests confirmed the superior strength while scanning electron microscopy (SEM) analysis displayed features that justify the possibility of using the curaua fiber as an effective reinforcement for polymeric composites.

Jan 1, 2006

By Jesse L. Duke

Outline ?Understanding the context ?The Business, political, social and legal environment ?Recipes for Success (three Ps) ?Develop effective Partnerships/relationships ?Plan carefully ?Actively Manage the ?Process? Business Environment ?Nunavut?Impressive mineral potential ?Emerging diamond industry ?Dominated by Juniors ?NWT ?Maturing Diamond industry ?Emerging oil and gas industry ?Yukon ?Alaska Highway Pipeline ?Junior-dominated exploration and development ?Growing acknowledgement in Canada of the importance of northern resources ?Shift of thinking: north-south infrastructure (vs. East-west)

May 1, 2006

By B Nielsen, H Lehto, J Rohleder, C Robben

Sensor-based ore sorting is being increasingly used to reduce the amount of low-grade and waste material processed in mineral concentrators. This type of preconcentration provides bottom-line benefits to users by reducing the amount of energy, water and consumables, as well as reducing capital cost. Existing operations can increase metal production, while previously uneconomic deposits and low-grade stockpiles can also be exploited. The technology can also be used to separate ore types for selective processing. The path to implementing sensor-based sorting may include:• geometallurgical evaluation• first inspection testing to investigate sensor response• bench-scale testing where sensor selection is not obvious or for difficult applications• performance testing in full scale sensor-based sorting machines• larger scale site-based piloting with a temporary semi-mobile plant installation. Sorting requires material to be suitably prepared and presented to the machines and typically this consists of crushing and screening to limit top size and optimise liberation. However, where material streams are suitably sized and prepared, additional equipment may not be required (e.g. the sorting of semi-autogenous grinding (SAG) Mill pebble streams).This paper presents a case study of economic upgrading of gold ore, by preconcentrating with sensor-based ore sorting. The case study examines sorting amenability, test work, the feasibility study through to implementation, with associated flow sheet development. The development process is analysed and evaluated with a view to rationalising the process for development of future projects. In addition, limited financial modelling based on expected results is shown to illustrate the benefit to the operation.CITATION:Nielsen, B, Rohleder, J, Lehto, H and Robben, C, 2017. Sensor-based ore sorting to maximise profit in a gold operation, in Proceedings MetPlant 2017, pp 131–146 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By D Craw, J Pope, B Peake

Southland contains over 70 per cent of New ZealandÆs recoverable coal resources, and an investigation into the potential effects of coal mining on SouthlandÆs water resources is therefore of interest. This paper investigates pit-lake water quality in relation to current mining activities within the sub-bituminous coal and lignite deposits of Southland. &nbsp; Water quality data was collected from pit-lakes in sub-bituminous and lignite deposits from October 2005 to March 2006. After periods of settled weather, turbidity increased with depth at the sub-bituminous pit-lake (10 - 21 NTUs from 5 - 30 m). In the stratified sub-bituminous pit-lake in March 2006, heavy rainfall caused higher turbidity in the epilimnion than the top of the hypolimnion (20 NTU vs 13 NTU) reflecting surface water runoff (up to 1993 NTUs) and epilimnion mixing. In contrast, turbidity at the lignite sites was variable due to the shallowness of the lakes, but noticeable increases following disturbance and adverse weather were recorded. High turbidity at the sub-bituminous deposits was attributed to the presence of clay minerals such as kaolinite whereas turbidity at the lignite sites was more likely short term and a result of heavier minerals such as quartz. &nbsp; Trace element concentrations at both sites were low when compared to mine waters in other coal areas in New Zealand and no samples exceeded ANZECC water quality trigger values for 80 per cent species protection. Pit-lake water pH levels were lower and more variable in the lignite deposit (4.18 - 7.30 vs 7.24 - 8.98 in the sub-bituminous deposits). In the lignite pit-lakes, higher concentrations of trace elements (eg Dissolved As - 0.034 ppm and Dissolved Mn - 1.09 ppm) and lower pH (ÿ4) were observed at the bottom of active pits compared to inactive pits. It is possible that quartz pebble conglomerates containing sulphide minerals within the lignite seams are responsible for this. &nbsp; Further investigation into the mine waters, waste rock and lake sediments will help get a better understanding of the results observed and long term processes that occur.

Jan 1, 2006

By W. Valderrama, D. G. Almond

Operation of large SAG mills requires a change in the conceptual approach to grinding processes. The traditional energy consumption criteria are now enhanced with new criteria derived from the mechanical dynamics of the mill load. This new approach demands instrumentation capable of providing accurate information about the load movement and the ratio of balls and ore inside the mill. This paper discusses two new performance enhancing tools available to meet these needs.

Jan 1, 2004

By Paulo F. T. Sachs

ERP systems have been widely implemented nowadays in several industries. However, ERP was originally designed to fit former MRP and MRP II users, and most of the ERP research has been focused on discrete manufacturing . On the other hand, process industries ? and mining in particular ? present many peculiar characteristics, which are difficult to comply with ERP systems standard functionalities. Again, very limited research has been developed covering enterprise management systems in mining. The objective of this paper is to identify, through an explanatory study that includes a case study methodology, how ERP systems manage the functional areas of the mining industry, and how they fit into the mineral value chain IT requirements. A secondary objective is to identify the gaps between ERP?s functional capabilities and the mining industry business requirements, and to point out the perceived benefits they generate to the companies.

May 1, 2004

By A Liu, T Ren

Gas explosion in underground coal workings can pose a serious threat to the safety of mine workers and the entire mine operations. Gas explosion is a very complex thermal-chain reaction in a confined underground environment. Based on combustion and explosion theory, three dimensional (3D) computational models were developed to simulate mine gas explosion flame and overpressure wave propagation in a single entry gateroad in underground coalmines. Six different explosion scenarios were modelled and compared with large scale experimental results and AutoReaGas simulations. Model validations show that the use of shear-stress transport (SST) k-? model together with eddy-dissipation model (EDM) produces good agreement with both experimental and AutoReagas simulation results. Modelling results demonstrated that the changes of temperature versus time can be divided into four stages, ie&#160;the initial condition stage, and periods of warm-up, active burning, and burnt-out. Assuming a limited volume of methane is involved in the explosion, the maximum temperature decreases as the distance increases from the explosion point, with the highest temperature reaching about 2460 K. Modelling results show that the evolution of the explosion flame shape experiences four typical stages, ie&#160;spherical flame, finger-shape flame, flame with the skirt touching the side walls (ribs) and tulip flame, which are similar to the pattern of a duct explosion. The pressure in the gateroad remains the same as the initial value before the arrival of the explosion wave and then increases rapidly to the maximum value. Modelling results from this study will be used for the design of explosion arresting devices and mine seals in underground coalmines.CITATION:Liu, A and Ren, T, 2017. Computational simulation of gas explosion and its propagation in single entry gateroad, in Proceedings Australian Mine Vent Conference 2017, pp 181–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By V. I. Zhuchkov, L. A. Smirnov, E. I. Arzamastsev, A. A. Babenko

A brief analysis is given for state-of-the-art of manganese and chromium ferroalloy production in Russia and their consumption by metallurgy plants. The main causes of low output of manganese and chromium ferroalloys, and ways to resolve the issue of ferroalloy production development are considered.

Jan 1, 2004

By M. Gaula

"Gold bearing deposits of the Witwatersrand basin are generally less than 2m thick and require conventional narrow-reef mining methods for extraction and employ explosives as a means of rock breaking. Optimal utilization of explosives is dependent on the overall design of the blast. The under-utilization of explosives arises when shot-holes are drilled inconsistently, overcharged, and when tamping is absent. This can be rectified by emphasizing the importance of good drilling practices as part of induction programmes and refresher courses. The project was aimed at determining whether or not explosives are being optimally utilized at project site. This was investigated through a study of the properties of explosives, mine standards, and recommendations for usage. Underground observations were made to determine whether or not mine standards were being adhered to. Historic data was obtained to establish the historic relationship existing between the quantity of explosives used (kg) and the production output (m2). This was then compared to the quantity of explosives the mine expects to use per unit of production. The results obtained were analysed to determine the presence and extent of over- or under-utilization. It was found that explosives are being under-utilized at the mine. More explosives are ordered than expected per unit of production. The explosives’ properties are not thoroughly exploited during blasting, thereby requiring the use of more explosives than prescribed. Paper written on project work carried out in partial fulfilment of BSc. (Mining Engineering)"

Jan 1, 2015

By J. A. Hayes

For over a decade the Osterberg Load Cell has been successfully used to determine the shear capacities of drilled shafts. Since the test method measures side shear directly, analytical complications due to the influence of end bearing resistance are removed. The data suggest that the side shear component of a drilled shaft&apos;s capacity is often more significant than end bearing. Given the interest in the use of side shear in drilled shaft design in compressible materials, it is important to examine factors that can influence capacity. We have found that some factors widely believed to influence capacity, such as slurry type, are not as important as commonly thought in most materials. Factors that are not usually considered as important, such as casing use, hoop spacing, concrete slump, concrete additives, spacers and rebar clear cover, seem to be more influential with respect to side shear capacity. For example, substantially lower than predicted shear resistance can occur when the rebar clear cover is small with respect to the cage diameter. We observe this most often in fine-grained cohesive soils. This effect can be exaggerated if the rebar cage has tight hoop spacing, if the concrete has low slump and if the hole is not straight. We have also noted that improper use of temporary casing can have a dramatic effect on side shear resistance. In some cases we have observed tested shear capacities reduced to less than 5% of either predicted or available shear values.

Jan 1, 2003

The extractive industry has been faced with a situation where there has been no systematic and formalised training and education structure available. Previous structures which were available, e.g. the quarrying diploma and the mining papers as a part of an engineering degree, have suffered the same fate as the Dodo. They are now extinct. &nbsp; In providing for a training strategy, the past strategies need to be examined and reasons behind their demise examined. This paper examines the reasons for past failures in education and training in the extractives industry, the factors that need to be taken into account in creating an education and training culture, the strategies required, the Government regulations and trans-Tasman agreements, and the quality management which must surround the entire training programme.

Jan 1, 1997

By R. Dahlke, J. A. Finch

"A campaign was undertaken during the greater part of 2001 at Noranda’s Brunswick Mine Concentrator to investigate the role of gas (air) superficial rate distribution (Jg profile) to the cells in the final Zn cleaning stage (bank of seven cells). Three profiles were tested: Balanced (each cell with same Jg), Increasing (from cell 1 to 7), and Decreasing, along with an “as found” profile in a parallel control bank. The experimental design allowed for two confounding factors, changes in ore type and circulating load. The Increasing profile consistently gave the best metallurgy (down-the-bank grade / recovery). The reason for improved performance was traced to the response of the first few cells. The Increasing profile gave the highest selectivity of sphalerite against non-sulphide gangue (NSG) in these cells with relatively even recovery per cell down the bank (10-15% based on feed to each cell). The other profiles gave lower selectivity and higher zinc recovery in the first cells (up to 25% in cell 1), which combined to reduce overall bank performance. The increased selectivity with the Increasing profile is attributed to the low gas rate in the first cells reducing water recovery and hence limiting entrainment of NSG gangue. The Increasing profile was subsequently configured for all four stages in the zinc cleaner circuit.INTRODUCTIONThe performance of a flotation circuit is largely the result of the operator’s response to visual clues. This includes manipulation of the gas (air) input and how it is distributed to cells in a bank. A lack of sensors prescribes this approach. Over the past ten years the Mineral Processing Group at McGill University have developed a set of gas dispersion sensors including one to measure gas superficial rate (or simply “gas rate”), i.e., volumetric gas rate per unit cell crosssectional area, Jg (Gomez and Finch, 2002). The device collects bubbles in a tube immersed in the pulp and infers Jg from the pressure-time curve generated after a valve is closed and air starts to accumulate. The usual units are cm/s. It is robust, reliable and suited for plant use.A version of the Jg sensor was tested extensively during 2000 at Noranda’s Brunswick Mine Concentrator (Dahlke et al., 2001). The results were sufficiently encouraging that a sensor was fabricated to suit local requirements (Insta-Jg). The sensor detected malfunctioning field instruments and flotation mechanisms, and demonstrated that gas distribution to cells in a bank “as found” had no particular pattern, or profile. Preliminary testing suggested that a balanced profile (i.e., all cells with the same gas rate) gave superior metallurgy (grade / recovery down the bank) than the “as found” profile. This observation prompted a focused campaign to explore the impact of the gas rate (Jg) profile, introducing the notion of “gas distribution management”."

Jan 1, 2004

By S. M. Carpenter

In response to the FY2008 Consolidated Appropriations Act (H.R. 2764; Public Law 110?161), the United States Environmental Protection Agency (USEPA) issued the final Mandatory Reporting of Greenhouse Gases Rule (MRR). The rule, signed by the USEPA Administrator, Lisa Jackson, on September 22, 2009, requires reporting of greenhouse gas (GHG) emissions from large sources and suppliers in the United States, and is intended to collect accurate and timely emissions data to inform future policy decisions. The MRR will go into effect on January 1, 2010, and a report of the total emissions for calendar year 2010 will be due to the USEPA by March 31, 2011. Under the final MRR, suppliers of fossil fuels or industrial greenhouse gases, manufacturers of vehicles and engines, and certain facilities that emit 25,000 metric tons or more per year of GHG emissions are required to submit annual reports to the USEPA. The gases covered by the rule are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFC), perfluorocarbons (PFC), sulfur hexafluoride (SF6), and other fluorinated gases as outlined in Table A-1 of Subpart A of the MRR, which is also provided in Appendix A of this report.

Jan 1, 2011

By Lars Arne Granlund

Due to the coarse structure of mining explosives, one has to model a finite reaction zone,contrary to C-J calculations, describing their detonations, i.e they become dependent of diameter and confinement, An effort within the DYNO group has been to investigate if the DSD theory ( originally developed by Bdzil, Stewart / Los Alamos ) can be used to describe major groups of civil explosives.The groups of explosives tested are dynamite, anfo, aluminised emulsion, heavy anfo and straight emulsions.

Jan 1, 1995