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By E. Tulcanaza

Mining companies normally establish exploration and research programs originated with actions in embryonic stage. At their early stages of development, these exploration and technological activities are subject to uncertainties that need, first, to be resolved, deciphered or, at least, mitigated for information reporting; and later, for valuation reporting. Under these circumstances, these exploration activities follow a sequence of development phases that range from exploration work to the profile, conceptual, and finally to basic engineering phases and construction. For information reporting, the International Template for Reporting of Exploration Results, Mineral Resources and Mineral Reserves integrates the minimum standards being adopted by the relevant professional bodies in Australia, Canada, South Africa, Chile, USA, UK, Ireland, and other European countries which set up the Committee for Mineral Reserves International Reporting Standards (CRIRSCO, www.crirsco.com). These standards are based on the progressive collection of relevant information to reduce present and future uncertainties over time under a context of transparency, materiality, and technical competence. For valuation reporting several procedures have been disclosed and applied. However, in the last decades financial instruments such as real options, decision analysis, and games theory have developed into a niche of great potential for mine valuation applications. The objective of this paper is to provide a summary of the information reporting standards prepared by the Chilean National Commission for the Qualification of Competent Persons in Mineral Resources and Mineral Reserves and show a procedure and an application of real options to the valuation of the sequential development phases of a mine asset from the exploration stage through up to full development.

Jan 1, 2007

By James W. Cameron

DESPITE the fact that, after oxygen and silicon, aluminum is the most abundant and widely distributed element in the earth's crust, it is, commercially, a modern metal. Attempts were made by Sir Humphrey Davy and other chemists to decompose alumina, the oxide, into its elements, but with unsatisfactory results, and it was not until 1827 that Wohler succeeded for the first time in isolating the metal in pure form. Some thirty years later, commercial production of aluminum was started in a plant near Alais, France, using a process developed by Deville which was a modification of that of Wohler. It was not, however, until around 1886 that possibilities of low-cost production were realized. Hall and Heroult discovered, independently, the now famous process for extraction of aluminum by the electrolysis of alumina (Al,O,) dissolved in fused cryolite. This discovery, with its subsequent effect in reducing the price of the metal, was perhaps the greatest single factor contributing to the remarkable growth of the aluminum industry. But only in the years following the Great War did aluminum begin to attain equal importance in many fields with other non-ferrous metals. Numerous factors, political and economic, in the past decade have had a profound effect on the industrial history of the metal. At present, systematic substitution of aluminum for other base-metals is proceeding at a rapid rate in such countries as Germany and Italy with a view towards 'economic self-sufficiency'. Quite naturally, ?the economic depression started extensive research and experiment in various industries in an attempt to improve efficiencies and lower costs. Partial answers have been found in the extended use of aluminum and its alloys. Even against the background of tremendous technological advance that has marked the past fifty years, the rise of the aluminum industry must necessarily stand out conspicuously.

Jan 1, 1939

By A. Karzhau, B. Aldamzharov, Y. Tussupbekov

"This case study produced for the metal mine operating in Kazakhstan, which has ventilation controlled manually and working continuously at maximum speed to keep air flowing through each part of the mine 24 hours a day. The mine auxiliary ventilation has been designed with the maximum length of ducting systems with extra air volumes to compensate for potential leakage. The mine provided auxiliary ventilation to all production stopes even to those, which for various operating reasons become temporarily inactive. However, mine safety has to consider risks associated with the deficit of fresh air for mine gases dilution and removal. The mine needs additional investments for re-designing ventilation network and therefore needs to estimate financial risks associated with it. The aim of this study is to conduct risk analysis for ventilation network optimisation processes at the operational metal mine in Kazakhstan. Mine ventilation surveys were undertaken for validation of the computerised ventilation model. The mine ventilation network modelling has been undertaken to be compliant with Kazakhstan mining regulations. Results of the mine ventilation optimisation processes were analysed in terms of financial risks for investments into reconstruction of the ventilation shafts, extension of the ventilation network, variable speed fans and automated regulators. Savings were resulted from improving ventilation system efficiency by reduce airflow in areas without mining activity and redistributing existing ventilation capacity. Based on savings derived from the optimised ventilation network an additional NPV has been received. Stochastic modelling use Monte Carlo simulation producing representation of possible outcomes for the additional NPV considering electricity pricing as a major variability. As result probability distribution for the optimised ventilation network demonstrates the additional NPV in a range of 1.6 - 2.2 million US$ in the corresponding defined value of 90%. Moreover, there is only 5% chance that the additional NPV to be less than 1.5 million US$. Conducted risk analysis for ventilation network optimisation processes gives considerations on volume of investments into the mine ventilation system.INTRODUCTIONCosts for mine ventilation are typically increasing when mines expand to deep levels. Some underground mines in Kazakhstan still use continuously operating fans at its maximum capacity. This is not helping to save energy and costs that are in many cases very significant. This case study produced for the metal mine operating in Kazakhstan, which has ventilation controlled manually and working continuously at maximum speed to keep air flowing through each part of a mine 24 hours a day. The mine auxiliary ventilation has been designed with maximum length of ducting systems and extra air volumes to compensate for potential leakage. The mine provided auxiliary ventilation to all production stopes even to those, which for various operating reasons become temporarily inactive. However, mine safety has to consider risks associated with the deficit of fresh air for mine gases dilution and removal from the mine workings (Sabanov, 2019). The mine needs additional investments for re-designing ventilation networks and therefore need to estimate financial risks associated with it. The aim of this study is to conduct risk analysis for ventilation networks optimisation processes at the operational mine in Kazakhstan. Mine ventilation surveys for validation of the computerised ventilation model have been undertaken"

Jan 1, 2019

By Stanislaw Trenczek

Natural hazards such as rock bumps, methane, coal dust explosions, airborne respirable dust, outbursts of gas and rocks, water, radiation caused by natural radioactive materials, spontaneous fires, and climatic hazards, occurring in the Polish hard coal mines, should be controlled. These hazards are characterized by different scale levels numbered from 2?5. To recognize the amount and levels of hazards, research works were carried out in 109 mining districts of mines belonging to Jastrzebska Spólka Weglowa, Katowicki Holding Weglowy and Kompania Weglowa. These are 86 % of all mines and could be regarded as representative of the majority of Polish mining. The hazards have been classified as regards the frequency of their occurrence as: commonly occurring ? with a frequency of 100 % (like airborne respirable dust and fire hazards), high occurrence frequency ? frequency from 60 to below 100 % (methane hazard ? 83.5 %, coal dust explosion hazard ? 92.0 %, and water hazard ? 99.1 %), medium occurrence frequency ? from 30 to below 60 % (rock-bump hazard ? 52.3 % and climatic hazards ? 51.4 %), and episodic occurrence frequency ? below 30 % (outburst of gas and rocks and radioactive hazards). The dynamics of effects of growth in hazard levels to their intolerable values is diverse. Some of them are passive in nature, which allows for longer observation of changes and appropriate early response (as for climatic and spontaneous fire hazards). However the majority of them take on the character of disasters, like methane or coal dust explosions and damage of the excavation structure ? as occurs after a rock-bump or rock outburst; and creation of an atmosphere unfit for breathing ? during open or spontaneous fires, or after gas outbursts containing methane. There are also latent hazards whose effects do not influence indeed a process of production; however they are detrimental to health when a worker is exposed for a long time to airborne respirable dust and radiation. For other types of hazards a level of danger may be only estimated. Since the systems monitoring allows a wider range of control, therefore, aside from rock-bump and methane hazards, there are monitored also fire hazards including measurements of other air parameters (velocity, pressure, humidity, temperature, O2, CO2 concentration). A few types of monitoring systems are used in Polish mines, like the monitoring systems for environmental parameters such as SMP-NT, SMP-NT/A, the telemetric systems CST-40, CST/A, including the computer-aided system for methanometry control officer SWµP, the computer-aided measuring systems KSP-1, KSP-2, KSP-2C, or the production and safety control system VENTURON. The underground part of the systems monitoring of natural hazards contains measuring devices and equipment for automatic control (power-off) of machines and electric devices in case of increased methane hazard. The surface part of the monitoring system allows the measuring data to be visualized and pre-alarm (warning) and alarm states to be displayed. Furthermore it makes it possible to archive and report the data and to control the underground supply and signalling devices. The EMAG Institute developed monitoring methods to extend a measuring range of monitored parameters (such as methane and fire hazards) as well as to monitor so far unmonitored hazards like dust hazards (by continuous monitoring of dust levels in mine air) and climatic hazards (by online monitoring climatic parameters of mine air).

Aug 1, 2013

By D. R. Lentz, C. J. Beaumont-Smith, S. H. Mcclenaghan

"Abstract - The Louvicourt Au-Ag-Cu-Zn-Pb sulfide deposit is hosted by a Middle Ordovician calc-alkaline sequence of aphyric rhyolite flows and associated fragmental rocks at the top of the Flat Landing Brook Formation. The Zr/TiO2 (average = 0.110) and Y/TiO2 (average = 0.021) ratios in the footwall felsic volcanic rocks are consistent with known values for the Reids Brook member. The deposit consists of two concordant lenses of semi-massive to massive sulfides, approximately 150 m long and up to 9 m thick, which represent a fold repetition of a single exhalative horizon. The deposit contains a geologic resource of 136 000 tonnes grading 1.2% Pb, 1.0% Zn, 0.4% Cu, 90.9 g/t Ag, and 0.96 g/t Au; the deposit locally contains elevated Au (2.9 ppm) and Ag (320 ppm) contents. A laterally continuous iron formation that contains barite caps the deposit, and is gradational vertically and laterally into laminated siltstone. The exhalite confirms the stratiform nature of this deposit, but a large percentage of sulfides occur as late replacements of altered felsic fragmental rocks in the footwall. Abundant examples of colloform pyrite and perlitic and spherulitic textures in volcanic clasts are well preserved. The base- and precious-metal content of the Louvicourt deposit is atypical of the Bathurst Mining Camp (BMC). Reported assay data (n = 27) indicate an average Pb/Zn ratio of 2.6, the highest in the BMC (average = 0.39). Lead exhibits a strong Spearman Rank correlation (r' = 0.92) with base metals throughout the sequence, indicating a preponderance of galena in both the stockwork and stratiform zones. The Ag and Au contents in this deposit are among the highest in the BMC and exhibit a Au-Ag- Cu-Pb association. Barite-rich exhalative pyrite exhibits a moderate Au correlation with Ag (r' = 0.77; n = 10) and Cu (r' = 0.76) and occurs in portions of the exhalative sulfides that are enriched in Pb. Chemical exhalative rocks are conformably overlain by trachy-andesitic volcaniclastic (possibly pyroclastic) rocks that are assigned to the Little River Formation. These are enriched in Nb (average = 38.4 ppm) and P2O5 (average = 0.17 wt.%), and have much lower Zr/TiO2 (average = 0.056) and Y/TiO2 (average = 0.0062) relative to rocks higher in the hanging wall. The intermediate volcanic rocks are conformably overlain by massive to pillowed basalt flows and related hyaloclastite that have Nb/Y = 0.60 and high TiO2 contents (average = 2.8 wt.%). This chemistry is consistent with rocks of the Brunswick Mines member (Little River Formation), except that these rocks are considerably enriched in P2O5 (average = 0.82 wt.%). This syngenetic exhalative deposit is unique for the BMC with a high Pb/Zn and elevated Au and Ag contents, as well as an epithermal signature (Sb-Ag-Au-Tl-Hg), analogous to high sulfidation volcanogenic massive sulfide deposits. Its intimate relationship with an emergent felsic dome (Flat Landing Brook Formation), chlorite-silicate-oxide-sulfide exhalite (locally hematitic), and the abundance of barite are classical features of many of the Kuroko deposits."

Jan 1, 2006

By K. Scalise, M. Teixeira, K. C. Kocsis, J. Parrish

"This paper aims to introduce and discuss a newly developed algorithm, which can be uploaded on smart watches and other mobile devices to inform and protect underground personnel working in hot and humid environments. Using this algorithm, the metabolic rate (M) of a worker can be determined in “real-time”. In addition, besides warning signs and alarm signals emitted by the smart watch, the algorithm has the ability to determine work-rest time periods based on the worker’s physiological parameters (e.g. age, height, weight, gender) and the climatic parameters (Td, Tw, flow velocity). This paper also investigates whether a re-designed auxiliary ventilation system can provide appropriate work conditions in the production stopes. INTRODUCTION An underground environment with high temperature and humidity conditions generated from various heat and moisture sources can significantly affect the thermoregulation processes of the human body. This can lead to heat-related illnesses such as heat rash, heat cramps, heat exhaustion, and heat stroke. Heat stroke is a serious illness that carries a high risk of fatality, if the underground workers are not immediately treated and the climatic conditions are not corrected (McPherson, 1993). There are two methods used to control the climatic conditions in underground mines: (1) Using ventilation and cooling systems to reduce the thermal stress on the mine workers, and (2) Reducing the heat transferred to the ventilating air from major sources such as: strata, auto-compression, mining equipment, groundwater, blasting, etc. The heat from strata and auto-compression is transferred to the ventilating air at varying degrees, based on factors such as the virgin rock temperature (VRT), the thermal properties of the surrounding rock formations, and the surface air temperature. However, the use of mining equipment and blasting processes can be managed to reduce their contribution to the mines’ overall heat load. To provide appropriate work conditions, selecting the most suitable cooling method depends on the level of heat to be removed, the location of the problem areas, and economic constraints (Brake & Bates, 2002; McPherson, 1993). Because every mine is unique, it is essential to monitor the climatic conditions to select the most appropriate method of cooling. A majority of the time, simply adjusting or re-designing the auxiliary ventilation system can efficiently remove the heat and dilute the contaminants. This may involve moving the ducting system, changing the size of the duct, changing the size of the auxiliary fan, or switching from forcing to an exhausting fan arrangement. If the required air volumes are higher than the existing primary ventilation system can supply, other measures may need to be taken to increase the airflow delivery. This may include regulating the flow in some areas of the mine to increase airflow to the desired area, adding booster fans, or replacing the primary fans."

Jan 1, 2019

By A. Haldar

This study focuses on the flow characteristics of hypereutectic Al-Si alloys in thin sections. The pattern assembly consisted of spiral horizontal patterns, 6.25 mm (0.25 inch) and 12.50 mm (0.50 inch) in thickness with a common sprue. Al-Si alloys with silicon levels of 14%, 18% and 22% were poured with superheats of 60°C, 115°C and 170°C. It was observed that metal fluidity (in terms of flow length and metal velocity) increased with increase in silicon levels and superheat for both section thicknesses. It was also observed that, for a section thickness of 6.25 mm (0.25 inch), silicon level had more pronounced effect on the metal fluidity. For 12.50 mm (0.50 inch) thickness, both silicon level and superheat affected the metal fluidity. The surface hardness of the castings increased with an increase in silicon level of the alloys at the gate and the flow tip. Detailed study of the flow tip was also carried out with a view to understanding the effect of silicon level and superheat on undulated flow length, surface hardness and microstructure.

Jan 1, 2007

By A. Consigny

New "clean technologies" to treat mining and metallurgical effluents containing dissolved metals have been successfully applied at mine sites in North America and Asia, treating water flows up to 24,000 m3/day. These clean technologies offer significant benefits compared to conventional alternatives and provide a sustainable solution that eliminates residual waste sludge, improves water conservation, generates revenues from wastewater, and delivers overall improvements to the environment. This paper will profile these technologies, and provide best practice case study examples of their application at mining operations, including data for water chemistry, flows, water quality, capital and operating costs, and life cycle costs of treatment.

Jan 1, 2011

By M. Yao, D. Thibodeau

"Selective mining, such as post pillar cut and fill, is used in large, flat, irregularly shaped ore bodies where ground stability is to be maintained. This selective mining is used to open the stope to the full lateral extent of the ore body in order to minimize the dilution and maximise the recovery. For increased mining depth, design of the post pillar becomes more challenging since those pillars will eventually fail as mining progresses upwards. The post pillar should be designed such that failure does not occur at the early mining stage, such as at the first cut. After mining progresses upwards, the post pillars are expected to fail but be confined by backfill. In order to maximise ore recovery, both drift width and post pillar size must be designed adequately with a consideration of all geomechanic parameters. This paper will describe the process used to design post-pillar cut and fill for one of the ore bodies in Vale’s Copper Cliff Mine using a combination of both empirical deterministic and numerical modelling techniques. By utilizing both empirical deterministic and numerical modelling techniques drift width and post pillar size can be effectively designed. Current post pillar cut and fill design in the existing Vale operations are used to validate the design for Copper Cliff Mine. INTRODUCTIONCopper Cliff Mine is located within the Copper Cliff Offset in the limits of City of Greater Sudbury, Ontario, Canada, as shown in Figure 1. The Copper Cliff Offset extends about eight kilometres south from the Sudbury Igneous Complex into the footwall rocks. Until 2008, the current Copper Cliff Mine was operated as two separate mines i.e. North Mine and South Mine. However, as part of restructuring of Vale Ontario Operations, the North and South Mines were merged in 2009 to form the “Copper Cliff Mine”."

Jan 1, 2015

By L. J. Bryson, C. A. Biley

"Anglo American Platinum’s Rustenburg Base Metals Refiners (RBMR) produces Ni and Cu cathode from slow cooled converter matte after Platinum Group Metals (PGMs) are magnetically separated for further processing. In 2010, execution of the RBMR expansion project was commenced to increase the production capacity to 33 ktpa Ni. The expansion, which is currently still in a ramp-up stage, brought about several fundamental changes to the circuit chemistry, including the installation of a dedicated Pressure Iron Removal (PIR) autoclave. This provided an independent outlet for iron from the refinery, which previously deported to the residue from the leach circuit and was toll refined. At the same time as changes in the circuit associated with the RBMR expansion were being made, the plant experienced a significant increase in iron and copper units per nickel unit in the feed. The decoupling of the leaching and iron removal process steps has had significant advantages for the robustness and control of the overall circuit, in particular pertaining to the preparation of a nickel electrolyte of sufficient purity to produce LME grade nickel. This paper details the primary changes to the RBMR circuit chemistry with a particular focus on iron deportment and the benefits derived from the installation of the PIR autoclave.INTRODUCTIONAnglo American Platinum mines and refines Platinum Group Metals (PGMs) through a complex processing pipeline in its South African operations. Mined ore is first treated through several mineral processing stages, geared to the recovery of base metals and associated PGMs, followed by smelting and refining operations that aim to separate base metals from PGMs and recover the value components to purified, saleable products. The focus of this paper is the Rustenburg Base Metals Refiners (RBMR) complex which receives a PGM-containing converter matte, then physically separates PGMs and base metals, and recovers nickel and copper to cathode by utilising leaching, precipitation and electrowinning processes.With new mining operations coming online and the continued increase in PGM ore arisings, it was necessary to undertake an expansion project at the Base Metal Refinery (BMR) to increase production capacity from 21 ktpa to 33 ktpa Ni. Complicating the expansion project was the requirement of continued production through all stages of design, construction and implementation and, due to stringent capital constraints, the utilisation of all existing equipment installed during a previous expansion in 1981. Against this backdrop, the expanded BMR flow sheet involved significant changes to the chemistry, especially iron management. These changes in iron management allowed for the separation of iron and copper residues and significantly increased the robustness of the plant to changes in feed mineralogy as well as the potential to increase production duties of the existing equipment."

Jan 1, 2016

By Piotr Malkowski

Studies on the properties of rocks heated to high temperatures are rather rare. Such research is occasionally conducted for example; in areas around nuclear power plants. The national Polish coal gasification (underground coal gasification, or UCG) project has, however, forced the analysis of the geomechanical properties of heated rocks in the vicinity of a designed geo-reactor. Ukrainian experience with UCG show that rocks up to 2 m from the burned coal seam be at a temperature > 600ºC. Such a high temperature will undoubtedly influence their physical properties. This paper presents studies on the strength and deformation properties of carboniferous rocks in the Upper Silesian region, where the UCG process is planned. Three types of rocks were tested: claystones, mudstones and sandstones. Laboratory tests of these rocks evaluated compressive strength, elastic modulus and weight loss. An evaluation of the results of the tests comparing the thermal conductivity of rocks and their specific thermal capacity was then carried out. All of the rocks studied were heated to 300, 600 and 1000ºC, and also evaluated at room temperature. This procedure shed new light upon the behavior of heated rocks in relation to their distance from the designed geo-reactor. The test results presented were developed within Research Task No. 3 ?Developing a technology of coal gasification for efficient production of fuels and electric power?, financed by The National Centre for Research and Development under strategic research and development programme ?Advanced Technologies for Energy Generation.?

Aug 1, 2013

By J. W. Choung, T. Fu, Z. A. Zhou

An on-line visualization technique and methodology was developed to investigate the role of fine sphalerite (< 10 um) aggregation in flotation. The images of particle aggregates under different operating conditions were recorded and analyzed. The effect of impeller design on particle aggregation was demonstrated. This difference was not mainly due to the energy input into the system, but due to the resultant hydrodynamic conditions created by the impeller and their effect on particle interactions. The recorded image showed that adding fine silica (- 5 um) did not interfere with fine sphalerite aggregation, thereby showing no effect on the sphalerite recovery. Effect of the enlarged aggregate size on increasing flotation recovery was confirmed. Although Malvern Mastersizer produced consistently lower estimates of aggregate size than those by the image analysis, both methods responded to the changes in operating conditions in the similar trend. It was shown from this study that on-line visualization technique is a powerful tool for studying fine particle aggregation and morphology in the context of diagnosis for the flotation separation.

Jan 1, 2004

By Marc Piard

In a cool mine, tapping high-pressure lines through reducing valves lowers the temperature beyond remedy. It is the writer&apos;s suggestion that, for low-pressure work, law-pressure air ,should be generated in a compressor installed underground adjacent to the work, and that the jacket-water of the compressor should be utilised for re-heating purposes. Such a system of compressed air distribution, designed especially for service in cool mines, is described in the following notes. The suggested system includes a three-wire pole line from the sub-station to the opening nearest to the working face, with a cable connection extending to the latter from the openings; an electrical centrifugal unit; a reservoir excavated in the ground; and a distribution line, re-heated by jacket-water. As regards the reservoir, it may be pointed out that in many mines there are blind or abandoned tunnels that could be used for the purpose. The centrifugal type of compressed air machine is a comparatively new departure, and it was formerly considered that such a machine, operating at less than 1,000 kilowatts per unit, would be commercially impracticable. At the present time, however, these machines are being built in Europe for as little as 400 kilowatts per unit, and as much as 110 lb. per sq. inch pressure. One advantage which these centrifugal machines have over other types is that they may be driven by plain induction motors, without the help of special starters-a consideration of the first importance where the electrical regulations are severe.

Jan 1, 1926

By Irving Wigden

The world is fast becoming information based. Mine companies migrate business infrastructures to be handled electronically. Suppliers move onto the worldwide web. In this ?e-world? successful suppliers will recognize they no longer trade in just equipment, but in knowledge. Companies can no longer just provide products and services, but instead must find ways to harness their knowledge to provide new value for customers. Mine customers will be attracted to suppliers that can help them streamline the process and use Information Technology to optimize operations, increase profit, reduce cost and enhance shareholder value. With the continued move to industry standard communications and software platforms, technology that formerly stood alone can now be integrated with other technologies. This creates more powerful systems that mine operators can use quickly, easily and cost effectively. These unified architectures improve productivity, provide higher asset optimization and allow more informed decision-making. As a leading supplier of process automation solutions for the industry, ABB provides a dynamic range of such control systems. These systems are designed for instrumentation controls, variable speed drives, electrical distribution, electrical equipment and related services for Mine Automation. Enhanced by ABB´s new family of integrated software solutions ? collectively known as Industrial IT ? ABB´s control and Scada systems place you in the best position to optimize your plant, process and enterprise operations. The paper discuss system integration and installation of High-Tec system in an underground mine. ABB has the ambition to be a System Integrator and co-operate with partners in different areas of technology. To day it is a problem to find one Supplier that can be responsible for the complete Automation System. The design of the system is also much depending of the design of the mine and also which caving procedure that is used in the current mine. Much of the work must be done in a feasibility study and during the design phase. If there is careful planning and consideration during these phases is vital in order to avoid costly changes during the commissioning phase The paper will also include a presentation of the benefit of using Automation in an Underground Mine, and how important the integration of the Human Being is to the Automation System. The most profit gained in mining industries are received when the mines can reduce internal and external disturbances in the production flow and speed. Must of the experience and discussed in this paper is from advanced technology, that has been developed in Scandinavian and adopted of LKAB in Kiruna. The author of this paper has been responsible för the Automation projects in the Kiruna Mine during 1994 - 1999. These projects include: Broadband communication of data, audio, compressed video in one data stream. Control System for Haulage -1045m Automation of Load Haulage and Dumping machines (LHD) Control of Production Drilling Riggs from a Central Control Room.

May 1, 2002

By C. O. Aksoy, H. Kose, K. Ozfirat, T. Malli, A. Gonen, S. Gurgen

In selecting mobile mining equipment, factors including availability, useful economic life, maintenance and operating costs, and spare parts availability are considered. Given these factors, trucks and shovels with different capacities are selected. Optimizing equipment for pit and hillside quarry cases, where 8% and 10% ramps are commonly in use, were examined; the effect of other mining activities such as drilling and blasting on unit cost were considered. In principle, 20 m to 25 m high benches should be economical for downhill haulage, and 7 m to 10 m low benches economical for uphill haulage. However, practice of both mining styles favours 10 m to 15 m bench heights. Hence, the analysis here was carried out with the field experience bench height range. In the study, a truck-shovel optimization was based on the movement of 5 to 20 million cubic metres (in 2.5 million cubic metre increments) of overburden stripping at the Eynez open pit mine in the Soma region of Turkey. The outcome showed that low-capacity shovels were unfavourable due to high production expectations. High-capacity shovels were also unfavourable due to health and safety issues causing high instances of impact vibration on trucks during the loading cycle and a decrease in foreseeable unit lifetimes. The number of shovel passes required to load a truck ranged from three to six. Trucks with high-capacity bodies were deemed uneconomical due to high investment and operating costs.

Jan 1, 2005

By Irving Wigden

The world is fast becoming information based. Mine companies migrate business infrastructures to be handled electronically. Suppliers move onto the worldwide web. In this ?e-world? successful suppliers will recognize they no longer trade in just equipment, but in knowledge. Companies can no longer just provide products and services, but instead must find ways to harness their knowledge to provide new value for customers. Mine customers will be attracted to suppliers that can help them streamline the process and use Information Technology to optimize operations, increase profit, reduce cost and enhance shareholder value. With the continued move to industry standard communications and software platforms, technology that formerly stood alone can now be integrated with other technologies. This creates more powerful systems that mine operators can use quickly, easily and cost effectively. These unified architectures improve productivity, provide higher asset optimization and allow more informed decision-making. As a leading supplier of process automation solutions for the industry, ABB provides a dynamic range of such control systems. These systems are designed for instrumentation controls, variable speed drives, electrical distribution, electrical equipment and related services for Mine Automation. Enhanced by ABB´s new family of integrated software solutions ? collectively known as Industrial IT ? ABB´s control and Scada systems place you in the best position to optimize your plant, process and enterprise operations. The paper discuss system integration and installation of High-Tec system in an underground mine. ABB has the ambition to be a System Integrator and co-operate with partners in different areas of technology. To day it is a problem to find one Supplier that can be responsible for the complete Automation System. The design of the system is also much depending of the design of the mine and also which caving procedure that is used in the current mine. Much of the work must be done in a feasibility study and during the design phase. If there is careful planning and consideration during these phases is vital in order to avoid costly changes during the commissioning phase. The paper will also include a presentation of the benefit of using Automation in an Underground Mine, and how important the integration of the Human Being is to the Automation System. The most profit gained in mining industries are received when the mines can reduce internal and external disturbances in the production flow and speed. Must of the experience and discussed in this paper is from advanced technology, that has been developed in Scandinavian and adopted of LKAB in Kiruna. The author of this paper has been responsible för the Automation projects in the Kiruna Mine during 1994 - 1999. These projects include: Broadband communication of data, audio, compressed video in one data stream. Control System for Haulage -1045m Automation of Load Haulage and Dumping machines (LHD) Control of Production Drilling Riggs from a Central Control Room.

May 1, 2002

By Michel Épiney, COREM, Mario Drapeau, Caroline Olsen, Claude Bolduc, Benoit Levasseur

"Several metal sulfide minerals (such as copper, zinc and iron), generally abundant in precious metal-containing ores, are known to dissolve during the cyanidation process. These unwanted reactions consume a significant amount of cyanide and oxygen, which is required for the extraction of gold and silver. Leaching kinetics of sulfide minerals are very fast in contact with oxygenated cyanide solutions. Therefore, the solution quickly becomes charged with oxidation products that are mostly metal ions, metallo-cyanide complexes, metal oxides and other sulfur species including thiocyanate, sulfides, polysulfides, thiosulfate, sulfites, sulfates, etc. COREM’s Extractive Metallurgy team has been conducting a research program on the improvement of the gold cyanidation process. As a part of this program, the current study aims to investigate the effect of certain operating parameters on the reactions involved during pre-oxidation and cyanidation. The effect of pre-treatment under ozone was investigated using an industrial pulp recreated from process water (charged with thiocyanates) and homogenized flotation tailings material from Agnico Eagle's LaRonde mine. In terms of mechanisms, the ozone treatment provides a complete deactivation of the material surface (characterized by EDTA extraction) and the solution (characterized by Ionic chromatography). This resulted in a lower reactivity of sulfide minerals that led to substantial gains in terms of consumption of cyanide and thiocyanate formation during the cyanidation process. The ozone-pre-treatment edges the classical pre-oxidation treatment (such as oxygen, hydrogen peroxides, etc) providing a quicker deactivation of the sulfide matrix and higher reagent savings in subsequent cyanidation process.INTRODUCTIONThe presence of sulfur in the process of gold leaching by cyanidation is a major drawback to optimizing the reagents consumption with suitable operating conditions. The coexistence of sulfide mineral species, such as pyrite, chalcopyrite, pyrrhotite or sphalerite along with the gold-bearing ore have, indeed, a negative impact on the extraction of precious metals by cyanidation (Bayat et al., 2003), (Azizi et al., 2010). These minerals are known to dissolve with cyanide under alkaline conditions and release in the slurry different kinds of sulfide by-products like polysulfides, thiosel, sulfite and sulfate (Seal II & Hammarstrom, 2003) (Breuer et al., 2008a), (Marsden & House, 2006) (Ghasemian Langeroudi et al., 2013). Once these sulfide by-products are released in solution they react with cyanide to form thiocyanate (Marsden & House, 2006) (Breuer et al., 2008b). The consequence of the dissolution of these cyanicides, is a significant increase in cyanide consumtpion as well as a slow-down of gold extraction."

Jan 1, 2016

By A. Nielsen

"The Polaris mining operation (Fig. I) is located on Little Cornwallis Island in the Canadian Arctic, an area with a very limited shipping season and a hostile climate. The operation consists of the underground works, barge-mounted concentrator facilities, concentrate storage and shipping facilities, a personnel accommodation complex and an airstrip.The electrical energy for the operation is provided by four 2.3 MW diesel-generators installed on the barge. The power is distributed through a 4.16 KV system connected directly to the generators and to the large motors. All other loads are supplied at 600 V or 120 V.The power plant has been designed as a Total Energy System with maximum energy efficiency and thus designed for maximum heat recovery. The waste heat recovered on a year &apos;round basis is expected to be sufficient for the process heating and drying as well as the space heating for offices and accommodations. The engine cooling system consists of two glycol-water loops, a "" cold"" loop for charge air and lube oil cooling and a ""warm"" loop for jacket water cooling. Each loop is complete with heat exchangers f or heat recovery and out-door forced air radiators to dispose of excess heat. A water loop in the concentrator area transfers the heat from the jacket water loop and the exhaust gas boiler to the space heating equipment, the process and the heating system for the accommodations. Part of the exhaust gas is diverted to the concentrate dryers.IntroductionThe Polaris Mine is a highly mechanized, trackless mine with access through a decline. Drill equipment is electrically powered to minimize fumes and heat. Dry development and production drilling eliminates the need for an underground water supply system.The concentrator, power generators, work shops and auxiliary facilities are located on a barge which is beached in a prepared berth on the shore of Crozier Strait. Oil storage tanks, concentrate storage and accommodation buildings are built on shore. The concentrate storage building ha s a 12-month capacity and is fed from the concentrator by a conveyor system.The accommodation building houses up to 240 people, includes administration office, dining and recreation facilities. The complex is housed in on e interconnected building with public use areas alternating with accommodation units.At full production annual concentrate shipments will amount to about 220,000 wet tonnes. This will be accommodated by about 8 shipments during the regular shipping period-August 15 to October 15. Re-supply of general cargo and fuel will be carried out annually in about 3 shipments within the same period."

Jan 1, 1984

By A. I. A. Salama, M. W. Mikhail

"The existing methods of block diagram manipulation and vanishing variable for flowsheet simplification used in coal and mineral processing circuit evaluation and optimization cannot be easily implemented on digital computer.The signal flowgraph technique is proposed to represent and simplify determination of the relationship between intermediate or end variable and the feed in the flowsheet. Typical and existing circuits are used to demonstrate the application of the proposed technique which can easily be implemented on digital computers.IntroductionRecently there has been much interest in the analysis and optimization of coal and mineral processing circuits to assist in the pre diction of coal and mineral processing plant performance. The block diagram and the vanishing variable were introduced and utilized in the analysis of plant flowsheet. Although the block diagram approach is useful, it requires manual manipulation of the circuit block diagram which may present difficulties in the situation of complex circuits. Moreover, it may not be easy to implement on a digital computer.In this paper, the signal flowgraph technique is proposed to represent the circuit flowsheet and to simplify the determination of relationships between intermediate or end variables (fractional mass) and the feed for any coal and for any mineral processing circuit comprising size and density separators. These relationships are utilized in the analysis and/or optimization of the circuit. The proposed technique is illustrated by considering typical and existing circuits."

Jan 1, 1987

By M. Jorgensen, I. Markland, D. Shuck

"The McLaughlin Mine owned by Homestake Mining Company is located 70 miles northeast of San Francisco in California's coastal range. The mine began operations in February of 1985. The mill currently processes 3,000 short-ton per day of sulfide ore that has an average grade of 0.15 ounces of gold per ton, plus another 3,000 tons per day in a newly completed oxide circuit. Annual production from the mine totals over 200,000 ounces.The sulfide ore extraction process involves three basic steps, grinding, oxidation of sulfide minerals in an autoclave, and cyanide leaching for recovery of gold in a carbon-in-pulp circuit. This process, which incorporates a new technology where oxidation of sulfide minerals is conducted prior to cyanide leaching to facilitate gold recovery, was successful from start-up. However, limitation in the grinding mills initially limited sulfide tonnage throughput.This paper discusses modifications made in the grinding circuit, both mechanical and operational, to resolve it deficiency. The SAG mill, in particular, was unable to achieve design tonnage initially and proved to be most troublesome. Complications occurred due to the hardness and variability of ore being processed, short component life, and a lifter /liner arrangement that had to be tailored to the particular circumstances at McLaughlin. IntroductionHomestake Mining Company's McLaughlin Mill, located in northern California, was designed to process a refractory gold ore at a rate of 3,000 tpd to render the ore amenable to cyanidation. Seven years transpired between discovery of the near-surface ore body in 1978 and the February, 1985 plant start-up. Development of the McLaughlin mill and open pit gold mine hinged on the use of autoclave technology to achieve design recoveries."

Jan 1, 1991