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This paper presents the results of research aimed at proposing new solutions in the area of belt conveyor elements. Many factors, such as energy consumption costs, and operating costs of belt conveyor elements, including belts, idlers and drives have an impact on the operational costs of conveyors. The paper presents special tests of new materials for the bottom cover of an energy-saving belt conveyor, which decrease rolling resistance. It also presents large-scale in-situ tests of a high-output belt conveyor for the purpose of simultaneous measurements of various types of conveyor belts (standard vs several energysaving types) under typical operating conditions of a lignite surface mine. Improvements in materials used for the bottom belt covers, supported by specially developed comprehensive tests of the new types of belts have provided valuable results of various proposed solutions. Since the tests of belts were done at exactly the same time and in the same operating conditions, direct comparison of the results is valid and should lead to a substantial decrease in the conveyors? drives? energy consumption, which will improve the effectiveness of belt transport and minimize its negative influence on the environment.

Aug 1, 2013

By L. Vinnett, T. Ledezma, F. Contreras, F. Díaz

"Mass balances in secondary grinding are subject to critical constraints mainly because of the unknown load distribution from the SAG mills, the uncertainties in the hydrocyclone split estimations and the lack of flowmeters in the key streams. In this paper, a methodology to support mass balances based on the use of radioactive tracer is presented. This approach was successfully implemented in two secondary grinding circuits of Minera Los Pelambres, which operate with ball mills of 21’ x 33.5’. The method allowed the load distribution of the SAG product (secondary grinding feed) to be determined. This load distribution was used as an input in the mass balance data reconciliation.The effective residence times of solid tracers were obtained in the secondary grinding equipment, where irradiated solid was used as a tracer. The residence times were obtained from the parametric deconvolution between the input and output tracer signals. The model fitting was performed to reconstruct the normalized output tracer concentration. Effective residence times of solid tracers in the ball mills ranged from 1.9 min to 9.5 min. The use of radioactive tracer measurement in grinding circuits is a powerful tool to consolidate mass balance results as well as to characterize grinding mills.INTRODUCTIONGrinding is the last stage of the comminution circuits. At this stage, the ore particles are reduced in size by a combination of impact and abrasion, either dry or wet (Austin & Concha, 1994). The grinding equipment mostly used in industrial operations correspond to horizontal tumbling mills (Wills & Napier- Munn, 2006). Tumbling mills employ steel balls or rods as grinding media. Ball mills, which are a type of tumbling mills, use steel grinding media with greater surface area per mass unit than SAG (semiautogenous grinding) mills or rod mills (primary grinding). Hence, the ball mills are suitable to obtain the particle size required in the next separation stages (Napier-Munn et al., 1996; Wills & Napier-Munn, 2006)."

Jan 1, 2016

By Helge B. Wurst, Michael P. Cipold, Jan F. Bachmann, Claus C. Bachmann

"In washability, the objective is to establish the set of maximum possible separation performance criteria for a given mineral feed. The method of choice for this has been the conventional sink-float analysis. Time, cost and safety aspects of the sink-float method have prompted the search for a new approach for establishing separation performance criteria, especially as performance levels of separator plants can be maximized if reliable information based on an analysis of washability in conjunction with particle size distribution, elemental constituency becomes readily available. The new method to establish washability and associated performance information utilizes at least two measurement technologies concurrently: single energy x-ray transmission and image processing. For porous or very inhomogeneous materials the results can be refined further by using dual energy x-ray transmission and image processing. The value of the collected data increases considerably if the washability data were additionally available in time to be considered in the control of the process plant. The incorporation of an automated washability monitor gives near real-time data that would impinge positively on the profitability of the plant operation. The method was extensively tested with a range of sample with different densities, varying from 1 g/cm³ (coal) to 5 g/cm³ (iron ore).INTRODUCTIONWashability of minerals like coal and iron ore is expressed by a curve or graph showing the results of a series of float-and-sink tests. Several of these curves are drawn to illustrate different conditions or variables, usually on the same axes, thus presenting the information on one sheet of paper. Washability curves are essential not only for the design but also for the operation of preparation plants.In determining the washability analysis, particle density is the underlying feature of all washability curves. Conventionally, the particles are separated into density fractions by immersing them in fluids of a predetermined density followed by skimming of those particles that stay afloat. The particles remaining afloat thus have a density lower than that of the fluid they were subjected to. The particles that remained at the bottom of the fluid container thus had a higher density higher than that of the fluid. By progressively increasing, for example, the density of the fluid and immersing the remaining particles so as to be able to skim the next density fraction, the particles would be fractionated into density groups. The liquids used range from aqueous solutions to organic liquids to suspensions. Unfortunately the liquids used for this separation process are often toxic and expensive. It stands to reason that a new method of determining washability is sought."

Jan 1, 2016

By Peter Hayes, Evgueni Jak, Taufiq Hidayat, David Grimsey, Denis Shishin

"An integrated nickel flash smelter is operated with Peirce-Smith converters at the Kalgoorlie Nickel Smelter. To improve the partitioning of arsenic between slag waste and matte product, an option to modify the slag–matte chemistry by addition of CaO was analysed. A combination of plant sample analysis, high-temperature laboratory experiments and thermodynamic modeling was carried out to evaluate the process options. The high-temperature experiments involved the re-equilibration of industrial matte-slag samples at 1225 °C and P(SO2) = 0.12 atm, rapid quenching in water, and direct measurement of phase compositions using electron probe X-ray microanalysis (EPMA) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LAICPMS). A private thermodynamic database for nickel sulfide smelting and converting was used together with the FactSage thermochemical software package to assist in the analysis of the distribution of elements between slag and matte as a function of CaO addition. The thermodynamic predictions combined with experimental data obtained in this study can be used to characterise the effect of CaO fluxing on the slag–matte thermochemistry during the nickel sulfide converting.INTRODUCTION At the Kalgoorlie Nickel Smelter (KNS), nickel sulfide concentrate is processed in an Outotec-type flash furnace to produce nickel matte containing +47 wt% Ni. Separation of nickel matte and waste slag from the flash smelting is enhanced through settling in the electric arc -heated zone attached to the flash furnace. The flash furnace matte is further processed in a Peirce-Smith converter to produce Ni-rich matte containing +66 wt% Ni (Crundwell, Moats, Ramachandran, Robinson, & Davenport, 2011). Iron silicate-based slag is used in the converting process at KNS. Most of the arsenic is contained in the final matte and very little of the arsenic partitions into the slag. Previous work by Font et al (Font, Hino, & Itagaki, 2003) shows that the distribution ratio of arsenic between calcium ferrite slag and nickel-matte (LAsslag/matte) is significantly higher than that between iron silicate slag and nickel-matte, where LAsslag/matte = (wt pct As in slag)/{wt pct As in matte} (1)"

Jan 1, 2017

By E. Trickey

In the mining industry there exists a constant drive for increased safety and productivity and decreased operating costs. This acts as a driver for implementing advanced technology. As more and more mining operations turn to new technologies, an observed bottle-neck for technology advancement has been the limitation of machine vision solutions available. LiDAR has been seen as a possible solution to the machine vision problem. In the past, a few studies on machine vision solutions have been undertaken by various groups involving scanning laser range-finders and millimetre-wave radar. These studies have done little more than highlight the limitations of both technologies in the mining environment. Little work has been done, however, exploring the applicability of LiDAR imaging technology for mining applications. Neptec Technologies Corp. has developed an obscurant-penetrating LiDAR (OPAL) sensor technology which overcomes the limitations faced by traditional LiDAR sensors when operating in a dusty environment, as well as advanced 3D real-time intelligence (3DRi) data processing algorithms that enable the real-time exploitation of 3D imaging data with sensors mounted on moving vehicles. Working with Teck Resources Ltd. and Barrick Gold Corporation, Neptec is adapting the OPAL sensors and 3DRi technology to mining applications. This paper highlights a number of real-time OPAL/3DRi based mining applications demonstrating how this technology overcomes the limitations of traditional LiDAR to provide a real-time machine vision solution that supports mine machine autonomy.

Aug 1, 2013

By F. H. Edmunds

Introduction This paper, it is hoped, will serve as an introduction to further work upon the origin of the soils and to a more complete interpretation of the geology of Saskatchewan from a study of the soils of the Province. The great difficulty that is encountered in mapping the structure of the prairie regions of the west must be evident to all who have made the attempt. The rarity of good exposures, due to the extensive coverings of glacial drift, is the greatest obstacle, making it difficult to determine the exact stratigraphical position of such exposures as may be found. In many cases palæontological evidence is lacking, or, if available, our present knowledge of the stratigraphy is insufficient to justify division of the formations into horizons; and until many of these formations have been subjected to petrographic investigation, little can be done in using lithological differences as an aid to the correlation of the usually sparse outcrops met with in the Province. Topography may be of the utmost value as an indication of geological structure when considered in conjunction with other evidence. It does not necessarily follow that, because an area in Saskatchewan has resemblances in surface configuration to an area of oil-producing land in Texas, there is sufficient justification for sinking money in wells without further investigation. Such - investigation should include the study of available soil maps.

Jan 1, 1929

By D. Janney

Kennecott's Utah Smelter commenced operations in June 1995 utilizing Outokumpu Flash Smelting (FSF) and Kennecott-Outokumpu Flash Converting (FCF) technology. After some initial teething and equipment problems the smelter achieved its design capacity in mid-1997 and now processes over 1.0 million tonnes of copper concentrate per year with exceptional environmental performance. The smelting furnace has operated for 11 years and the converting furnace for 5 years without major shutdowns. The first major smelter shutdown commenced in September 2006 after extensive planning. The FSF was completely re-bricked and the latest above and below bath containment systems installed. The FCF was inspected and re-bricked with some improvements made to the above bath containment system. The FCF life is now anticipated to be the same as the FSF. Numerous improvements and modifications were made to the rest of smelter facility including extensive upgrades to the dry electrostatic precipitators. Production ramp-up was smooth with the smelter now frequently operating at acid plant capacity.

Jan 1, 2007

By Matthew A. Perras

With growing populations, infrastructure projects are utilizing underground space to expand transportation networks, water supply and sewer disposal systems and hydropower facilities. These new projects require large diameter tunnels to meet the growing demands. As the tunnel diameter increases, not all rock mass properties are scalable and precedent experience becomes less reliable. One such non-scaleable property is lamination thickness. Numerical modelling was conducted to determine the influence of lamination thicknesses on a 16 m diameter tunnel. Five different areas of excavation response were found to exist for laminations ranging between 0.16 to 16 metres in thickness. For this tunnel diameter, critical lamination thicknesses of 6 metre and 1 metre were found to exist. Above 6 metres the excavation response was similar to isotropic models. Below 6 metres the stresses and yield are channeled by the lamination boundaries, increasing plastic deformation. Below 1m multiple lamination units become unstable and the displacements increase significantly and the shape and extent of the yield zone size changes dramatically. The yield zone is controlled by bed deflections and bed parallel shear. As the lamination thickness decreases tensile failure first begins in the haunch area and progressively extends above the crown until a self-limiting plastic yield zone shape is reach at lamination thicknesses below 0.4 metres. Conclusions drawn from observations at the Niagara Tunnel Project are those of the authors.

May 1, 2009

By D. K. Matlock, D. J. Hamre, J. G. Speer

Ultrafine ferrite (UFF) grains may be produced in surface layers of plate steels using controlled intermediate cooling followed by deformation. Experiments were conducted using a 0.12 C - 1.26 Mn steel on a Gleeble 1500 hot deformation simulator. Taguchi designed experiments were used to evaluate prior austenite grain size, intermediate cooling rate, intermediate cooling temperature, intermediate hold time and amount of reduction in order to observe the effects of variables and their interactions on the final microstructure while minimizing the number of required test runs. Evaluation of resulting microstructures and mechanical properties revealed a preferred thermal and mechanical history for developing ultrafine microstructures in surface layers of plate steels. Application of the fundamental concepts of phase transformations to industrial plate rolling is considered.

Jan 1, 2004

By G. E. Agar

This paper deals with the prediction of locked cycle flotation results from data developed from individual batch tests. A postulate is made that the distribution of material in a separation stage is determined by the chemical conditions and the flotation time and that this distribution can be characterized by split factors which are constants for a fixed set of conditions. With this premise, it is demonstrated that a steady-state balance can be calculated for a circuit. Although the necessary equations can be solved algebraically, a computer program was written that uses an iterative technique to arrive at the steady-state balance. The program is written so that a variety of circuits can readily be simulated. A number of examples are examined to demonstrate the validity of this simulation procedure. The sensitivity of the material balance to changes in the split factors was examined. Data developed from different flowsheets are presented on sulphide ores, on copper-nickel separation and on silver flotation.

Jan 1, 1978

By E. C. Sanford

A laboratory-scale batch extraction unit and operating procedure for studying the hot-water separation of bitumen from Athabasca tar sands are described. The extractor evolved from earlier units and has been in use by Syncrude Research for the past 10 years. By using a unit such as this, it is possible to study tar sand feed quality and the effects of chemicals on the hot-water extraction process, while process variables are held constant. Data are presented to demonstrate the importance of surfactants to the process and the interrelated role of inorganic bases and surfactants.

Jan 1, 1979

By M. L. Jeremic

The design of the long-hole sublevel mining method was originally based on the traditional assumption that the principal load was due to the weight of the overlying rock, and that the horizontal stresses are equal to one-third of the vertical stress. However, as mining progressed, the virgin lateral stress was found to be equal to or greater than the vertical stress. The virgin stress in the rock mass is not uniform throughout the folded orebody and adjacent strata. From detailed investigations, three basic patterns of virgin stress in ore panels have been inferred: uniform, bent and twisted. Stresses induced by stoping are up to three times greater than original stresses in the rock mass; they cause heavy ground conditions and make extraction of ore difficult. In the last ten years, the original mining system has been modified several times in order to destress the ground and improve the extraction of ore.

Jan 1, 1978

By C. E. Baltzer

This paper highlights the electric power situation in Canada, and introduces brief explanation of the salient differences between electrical practice in the United States and Canada. The availability of bask energy in the two countries is touched on, also the hydro versus thermal outlook as applying to Canada. De-v2lopment of thermal-electric power is dealt with in some detail, followed by Canada's thermal-electric power requirements, present and future. The fuel requirements for steam-electric generating plant are assessed on the basis of a survey recently made, and the location and size of the major thermal plant operations are given. Fuel contractual obligations on the part ?of suppliers and consumers are mentioned. Finally, an opinion is expressed in regard to the types of f.uel in ?demand on a regional basis with emphasis on the need for coal in the several areas dealt with.

Jan 1, 1958

By M. Krasowska

Dynamics of collision and kinetics of the bubble attachment to hydrophobic solid plates (Teflon) of different surface roughness were investigated. The experiments were carried out in such a way that probability of the collision and probability that the detachment will not occur were equal always 100%. Thus, it was possible to determine effect of the surface roughness on the bubble attachment (three phase contact formation, TPC) only. A high-speed camera (1182 Hz) was used to record the velocity variations, bouncing and time of attachment of the bubble colliding with Teflon plates having different surface roughness (5 different plates). Roughness of the plate surfaces was modified in a mechanical way using different abrasive papers. It was found that the roughness had a crucial influence on the time-scale of the TPC formation and attachment of the bubble colliding with the Teflon plates. Despite high hydrophobicity of all plates (contact angles 1100 -115º) it was observed that at the smoothest surfaces (called "Teflon I" and "Teflon II" and having surface roughness below 1 um) there was no attachment during the bubble first collisions. Prior to the attachment four or more "approach?bouncing" cycles of the colliding bubble were observed there and simultaneously the bubble shape varied rapidly within time intervals below 0.85 ms. Time of contact of the colliding bubble with the Teflon plates was very short; 2-3 ms. These results indicate that during that short time of the collision the liquid layer separating the colliding bubble and the solid surface did not reach a critical thickness of its rupture.

Jan 1, 2006

By C. I. Walker

Field tests at a number of large mineral processing operations have been undertaken to better understand the wear life impact of different aspects of pump design, materials of construction and maintenance procedures. Data are presented for wear rates, and typical result variability is explored. To improve the availability of pumping equipment in a milling circuit it is not only important to improve the wear life, but also reduce the variability in the wear life of components so that the incidence of premature failure is lessened. Localised gouging wear due to flow separation and turbulent eddy formation is often the point at which part-holing occurs. A number of improvements to the design of pump impeller and throatbush (suction side liners) to reduce the localised gouging wear are outlined. Also, results are presented on the use of composite materials (mix of metal, rubber and ceramic) for throatbush materials to protect specific areas against wear.

Jan 1, 2012

By A. Tylczak, C. Shook, A. Doogan-Smith, S. Loif, B. Hilscher, P. Nayak

"This paper discusses how to effectively conduct energy efficiency studies during the design of new mineral processing plants and plant expansions. Energy management studies for new plants are ideally conducted as part of the feasibility study, but can also be done at the detailed design stage prior to the purchasing of equipment. Energy management engineers work as part of the mineral processing plant design team.Such studies usually result in energy savings of approximately 3-8% of the predicted plant’s energy consumption and energy demand. Potential cost savings can be significant. A variety of mineral processing systems – crushing/grinding, pumping, materials handling, fans/blowers, compressed air, and others – are assessed within this study.Energy Management Information System (EMIS) studies can also be performed for the new plant or plant expansion, as an independent study. EMIS can be incorporated into the electrical and controls design of the plant.Most Canadian Utility companies fund new plant design studies and provide financial incentives based on the predicted energy savings and incremental cost of the more energy-efficient design. A new plant energy efficiency study improves the potential for energy reduction because only the incremental equipment cost is included in the project return-on-investment calculation. After the design and construction phases, energy efficiency projects must justify the entire cost of the upgrade, which is significantly higher than the incremental cost alone.This paper outlines the major steps of a new plant/plant expansion energy efficiency study, the available utility company incentives, and the areas yielding the largest potential energy savings.IntroductionThis paper discusses energy efficiency studies and energy management systems with regards to mining operations. Energy management refers to the systems of monitoring, analyzing, and optimizing energy usage within a facility. It includes energy efficiency optimization of the initial plant design as well as the implementation of an Energy Management System (EnMS) and Energy Management Information System (EMIS) for optimizing energy usage over the lifetime of the facility. An EnMS is the organizational framework and procedures for managing energy use; an EMIS is the system of monitoring, reporting, and tracking process energy use against targets."

Jan 1, 2016

By H. T. Michels

Recent laboratory studies show that several bacteria, known to be human pathogens, die when they come in contact with copper and copper alloy surfaces. The amount of live bacteria drops by several orders of magnitude, to zero, on copper alloys in a few hours. In contrast, no reduction is seen in the concentration of live organisms on stainless steel during the six-hour test period. Aluminum painted and coated surfaces and plastics would show behavior similar to stainless steel and show no effect. Coatings and other surfaces claiming to be antimicrobial showed little to no effect. These results suggest the selection of copper alloys for surfaces exposed to human touch can materially assist in reducing the transmission of infectious organisms. In order to make antimicrobial claims in the United States, the approval of the US Environmental Protection Agency (EPA) is required. The EPA-required efficacy testing is described and the test results are summarized. It is anticipated, that once regulatory approval is obtained, that this will facilitate the introduction of antimicrobial copper alloys in hospitals, nursing homes and other healthcare facilities, as well as schools, and public buildings. Some of the application and barriers, to entry into the healthcare markets are mentioned.

Jan 1, 2007

By D. R. Pyke

Many of the gold deposits in the Timmins• area show a close spatial association to ultramafic metavolcanics. Available analytical data suggest that ultramafic rocks contain significantly higher gold contents than other major rock types. In addition, recent analyses by Keays (1975) suggest that talc-carbonate alteration of ultramafic rocks releases significant quantities of gold. It is proposed that the ultramafic volcanics formed the principal source of gold for the deposits in Timmins, and that the gold was derived from the ultramafic flows when they were extensively carbonatized. Carbonatization of the ultramafic rocks and emplacement of the auriferous quartz-carbonate veins was probably coincident with the last major period of deformation in the gold camp. Delineation of hitherto unrecognized ultramafic volcanics could be an important guide to the discovery of further gold deposits.

Jan 1, 1976

By A. A. Goss

We investigate the relationship between corporate financial performance (CFP) and environmental and social performance (CSP) in a sample (n=165) of large, publicly traded U.S. mining and oil and gas firms. Using optimally scaled principal components analysis to generate aggregate measures of CSP strengths and concerns, we find higher concerns are related to higher volatility of unexpected earnings and discount rates. Furthermore, these earnings shocks are more likely to be negative as concerns increase. Decomposing this relationship shows that negative environmental performance dominates proactive environmental management as a driver of unexpected earnings, but proactive community efforts increase the magnitude of earnings shocks. We document some evidence of the strategic use of CSR, with those firms that have greater risk investing more proactively in CSR.

Aug 1, 2013

By R. W. Davis

INTRODUCTION CHURCHILL river was named for John Churchill, first Duke of Marl-borough and third Governor of the Hudson's Bay Company, in the latter part of the 17th century, some fifty years after the ill-fated Danish expedition, led by Munck, had abandoned the site of the now famous seaport of Churchill, as a worthless, cold, disease-ridden country. No other attempts were made to explore the interior until the river basin became a part of the grant to the Hudson's Bay Company and began to play its part in furnishing the luxury of fine furs to civilized people as it had furnished the necessities of food and dress for untold centuries to uncivilized natives. This was the sole contribution of the region to the economic life of the country for some two hundred and fifty years, until 1926, when the power site at Island Falls was discovered by engineers seeking a cheap power source to make possible the development of the great ore-body at Flin Flon. DRAINAGE BASIN OF CHURCHILL RIVER The river is some 1,325 miles long. Rising in the headwaters of the Beaver river, in east-central Alberta, it flows in an easterly direction across Saskatchewan and northeasterly across Manitoba to Hudson bay, through a remarkable basin of some 115,500 square miles, only 6,000 square miles less than the area of the British Isles. A journey down this river leads one through three distinct belts of country, each vastly different from the others geologically and in surface characteristics. For the first five hundred miles the river flows through a basin of 36,000 square miles of the great central-plains country, which is covered with fertile soil and carpeted in its southern part with prairie grass, which gradually gives way to the mixed forests of poplar, spruce, birch, and jackpine in the northern and eastern sections: About midway across Saskatchewan, bald-headed knolls and ridges begin to make their appearance as the river meets the western margin of the Canadian Shield. Then, for some seven hundred miles, it passes through country underlain by the pre-Cambrian rocks of the Shield, which continue to within one hundred miles of Hudson bay. Here the character of the country again changes to a low, clay plain underlain by sandstone, and through this 'clay belt' the river flows between steep clay banks, to empty into Hudson bay.

Jan 1, 1935