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By Robert B. Parsons

"Ontario and Quebec taxpayers will have to dig deeper into their pockets to pay more tax, according to budget papers tabled in these provinces in May 1993. Individuals will be hardest hit, but corporations will also have to ante up in the face of higher rates, reduced deductions, and new taxes.Up, up, and away...Somewhere in the bleak picture of the 1993 Quebec and Ontario budgets, there is a bit of good news for the mining industry.Careful scrutiny reveals:• Ontario will correct a capital tax provision which inadvertently penalizes flow through share issuers;• Quebec's flow-through incentives will be extended to December 31, 1995; and • both Quebec and Ontario will allow deductions for mine site reclamation payments.The industry may also find some comfort in the fact that Ontario's new corporate minimum tax will be profit-based (unlike the federal minimum tax), so that non-producers should not face a liability for this tax. There is some concern though, about Quebec's announcement that the refundable credit mechanism in the Mining Duties Act will be reviewed."

Jan 1, 1993

By J. N. Van der Merwe, M. Mathey

"The development and mechanical characterization of coal-crete, a composite material generated from coal fragments and some binder material, is described in this paper. Coal debris was obtained from a colliery in South Africa. The binder used in the study basically consists of cement and water, and further ingredients are added to the mixtures, such as sand, fly ash and polymers, in order to investigate alterations of the mechanical properties of coal-crete.Results from over 220 mechanical tests on coal-cretes with various binder mixtures give consistent trends for the material’s behaviour. Linear relationships are suggested between the uniaxial compressive strength, Young’s Modulus and the indirect tensile strength of the coal-crete.It is shown that mechanical properties comparable to coal can be achieved. Coal-crete is therefore suitable for physical modelling of mining situations in experimental studies and for use as backfill in underground coal mines. The latter application is particularly attractive when refuse coal is used as aggregate material. The indicated trends in this study may be used as a guideline for individual coal-crete design needs. However, some uncertainty remains as to the influence of particle shape, size and gradation, coal rank and age of the coal-crete. These aspects are recommended for further research."

Jan 1, 2015

By Fathi Habashi

Poland has a unique copper industry. Copper sulphide concentrates are smelted in six shaft furnaces to produce matte and in a flash furnace directly to blister copper. Anodic slimes from electrorefining are treated by a modern technology to recover the precious metals. INTRODUCTION Poland's copper industry began in 1950 when the old and relatively small mines Lena and Konrad, located in Lower Silesia, were drained and recommenced production. In 1957 the industry entered a period of rapid development with the discovery of a rich ore body in the vicinity of Lubin and Polkowice which was the basis for the establishment, in 1961, of the Copper Mining and Smelting Combine (KGHM). In 1991 the Combine was restructured into a state-owned, joint-stock company under the new name of KGHM ?Polska Miedz? (KGHM ?Polish Copper?). It consists of three mines, three smelting and refining plants, and one rolling mill, and produces about 4% of the world?s copper and about 7% of the world?s silver.

May 1, 2001

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Jan 1, 2012

By L. Yacher

Most metallurgical plants already have sophisticated control systems as well as a process-historian that manage thousands of real-time and historical variables. There exists a huge potential for operational improvement through the inference of patterns, correlations and cause-effect relationships within these records. The ability to run online and offline advanced multivariate statistical analyses represents a great potential for the mining industry, in various areas such as cathode quality improvement in an SX/EX plant, the analysis of the correlation between the ore characteristics and the mill throughput, the determination of early failure alerts for major equipment, etc. The background theory is described, as well as some practical experiences of operations in Chile and Peru. Cu2007

Jan 1, 2007

By Mengsu Hu, Yuan Wang, Jonny Rutqvist

Material interfaces and typical boundary conditions are boundaries influencing the existence, uniqueness and stability of numerical solutions of water flow in heterogeneous media. The Numerical Manifold Method (NMM) with a two-cover-meshing system is an ideal method to handle boundaries, considering its flexibility with no need to adjust mathematical nodes onto boundaries, the meshing efficiency, and its integration precision. In this study, we derive and compare two new approaches for boundary constraints, i.e., a discontinuous approach with Lagrange multiplier and a continuous approach with jump function in the frame of NMM. In the discontinuous Lagrange multiplier method (LMM), Dirichlet boundaries or the material interfaces are regarded as discontinuities which are linked by Lagrange multipliers. In the continuous Jump function method (JFM), the material interfaces are regarded as inner interfaces, where the refraction law is realized by constructing jump terms with discontinuity of hydraulic gradient in its normal direction. Both the continuous and discontinuous approaches make full use of the aforementioned advantages of NMM and are established based on a clear physical meaning of water flow by our energy-work seepage model. The newly derived boundary-constraint approaches were coded into an NMM water flow model and tested for precision and efficiency on different simulation examples. We first tested both LMM and JFM for an idealized heterogeneous model, comparing the numerical results with analytical solutions. Then we tested both approaches with a heterogeneous model and compared the results of hydraulic head and specific discharge. We proved that both approaches are very suitable for material boundaries considering the accurate realization of the boundary constraints and the flexibility with no need for mesh-conforming.

Jan 1, 2015

By M. Mohan Rao

A Sievert ' technique was used. The few determinations made on 10 per cent and 20 per cent V alloys did not show any deviations from Sieverts' law up to I>N2 = 1 atmosphere. The same held true for alloys of 0.2 per cent Ti. Nitrogen absorptions in Fe-Ti alloys, containing from 0.50 to 0.77 per cent Ti at 1,600°C, follow Sieverts' law at low PN2 values, but, due to the formation of a delta titanium nitride phase, deviate from this law beyond critical values of PN2? There is evidence that this phase is Ti1.1N. The behavior observed can be described by the followmg equations: Ti,.,N(o) = 1.7Ti + N K = (fT; ? % Ti)1?7 (f;;.? %~_) = 0.0020 K = fN. %~ = 0.042 '\)-:>N 2 I NTRODUCTJON Nitrogen's solubility in liquid iron-vanadium alloys was investi-gated briefly by Brick and Creevy ( 1), and more extensively by Kash-yap and Parlee (2) and by Pahlke and Elliott (7). Nitrogen's solubility in liquid iron-titanium alloys

Jan 1, 1963

By E. M. Timoshenko, A. V. Tarasov

The results of laboratory, bench-scale and semi-commercial investigations of a method for adding surfactant (technical-grade lignosulphonate) to the process of pressure leaching of nickel-containing pyrrhotite concentrates have been discussed. Lt has been demonstrated that feeding of technical-grade lignosulphonate distributed along the length of an autoclave ensures a reduction in its requirement by a factor of 1.5 to 2 as compared with single-point feeding; it also results in a decrease by 5% in the unit requirement of metallized iron-bearing precipitator in the process of non-ferrous metals precipitation and reduces by 0.05 to 0.1% (abs.) the nickel and copper contents in the tailings of the given process. Technical solutions have been proposed for commercial introduction of the process.

Jan 1, 2004

By Y. Chengxian

Many factors about the HIC (hydrogen-induced cracking) resistance of pipelines are discussed in this paper. The main factors that influence the ability of HIC are environmental and material factors. The chemical compositions, non-metal inclusions and microstructure are discussed in detail, while a group of tests on HIC resistance are done according to varying C, S, Mn and P contents in pipeline steels, different experiment time and different strength to the coupon. It is concluded that decreasing the amount of C and S can obtain good HIC resistance; the test time has an effect on the different microstructure of X70; microstructure is the most sensitive factor for the initiation processes of HIC.

Jan 1, 2005

By S. F. Guo, Z. F. Zhan, X. L. Huang, Y. Zou, S. W. Qi

"FLAC3D is an important numerical analysis software to study dynamic response of rock slope. In application of the program, the common issues such as absorbing boundary and the method to apply wave have been well studied. However, effects of model mesh size, damping and width of slope are still unknown. In order to make the result more convictive, this article has discussed the above issues systematically. It found that when the maximum mesh size is smaller than 1/10~1/8 of the smallest wavelength, the mesh size is smaller, the computational accuracy is higher. Meanwhile, values of damping and width of slope have no effect on the result. Additional, results of FLAC3D modeling on wave transmission across rock joints agree well with analytical solutions, so it has verified the capability and accuracy of FLAC3D on dynamic response of rock slope.INTRODUCTIONChina is a mountainous country accompanied with many earthquakes. Thousands of geological disasters are triggered by the Wenchuan Earthquake in Sichuan Province, and the majority of the disasters are landslides induced (Xu et al., 2009). Meanwhile, the paper (Li et al., 2003) points out five significant issues about dynamic loading in the area of geotechnical engineering, which includes the study of rock slope stability under earthquakes, and the dynamic response of rock slopes is one of its important study issues."

Jan 1, 2015

By Ashley Tews

In 2005, we automated a forklift-based Hot Metal Carrier to be capable of typical metal transfer operations around a smelter. The project was highly successful and the vehicle has demonstrated hundreds of hours of live autonomous operations to thousands of people from industry and the public. As a result of the exposure and success of the project, we have expanded its focus to demonstrate how various technology components can be utilised to gain benefits in other areas of industrial operations. These include asset tracking, vehicle usage analysis, pedestrian detection and infrastructure profiling. Each of these components was derived from the core autonomous vehicle technology suite and has shown a high potential for improving safety and efficiency of vehicle-related operations, and improved diagnostic processes for measuring deformations of bakes and furnaces. The autonomous vehicle project and its extended technologies are described in this paper.

Aug 1, 2013

By P. Duran

The metallurgical gas handling system at Chagres Smelter, like that of many smelters, can be the limiting constraint to processing more concentrate through the smelter. Mass and energy balances for the metallurgical gas handling system processing off-gases from the flash furnace and Peirce-Smith converters have been used by both operations and process engineering groups to help evaluate different operational scenarios in which the use of the installed capacity could be maximized and/or an operational strategy can be change with the purpose of removing a bottleneck or justifying an investment to relieve a constraint in the gas handling system. The present work describes the development of these process balances that were carried out in Exce®. The results were validated with operational data and, subsequently, some cases of industrial interest were simulated, detecting some conditions that were limiting the operation due to the present installed capacity in the Chagres Smelter.

Jan 1, 2007

By Y. Chengxian, F. Yaorong, Xinzhe. L.

Many factors about the HIC (hydrogen-induced cracking) resistance of pipelines are discussed in this paper. The main factors that influence the ability of HIC are environmental and material factors. The chemical compositions, non-metal inclusions and microstructure are discussed in detail, while a group of tests on HIC resistance are done according to varying C, S, Mn and P contents in pipeline steels, different experiment time and different strength to the coupon. It is concluded that decreasing the amount of C and S can obtain good HIC resistance; the test time has an effect on the different microstructure of X70; microstructure is the most sensitive factor for the initiation processes of HIC.

Jan 1, 2005

By O. C. Rojas, J. Sanhueza, J. C. Vargas

Empresa Nacional de Minería (ENAMI) is dedicated to the promotion of small and mid scale Chilean mining industry. Paipote, ENAMI Copper Smelter, processes a variety of mineral products as the result of this promotion. The mineral products characterize a wide variation of copper, iron, sulfur and precious metals content as well as the significant dispersion in the content of impurities, such as arsenic, antimony and bismuth. The Smelter Modernization Program, initiated in1997, introduced a series of technological and operational changes. The development of operational planning and control strategies was necessary to optimize the blending of a wide variety of concentrates and the control of metallurgical processes in order to ensure the stable operation, fulfillment of environmental regulations and the quality of produced copper anodes. A permanent optimization process carried out in the last decade led to the permanent increase of the smelting capacity and the production of anodes and sulfuric acid. Additionally, introduced improvements affected the smelter efficiency and metallurgical recovery, demonstrating the possibilities of the optimization of a small smelting facility reflected in good metallurgical and economic results. This paper presents the smelter evolution, introduced technological and process control changes as well as incorporated new reactors and equipment as a continuous process of optimization.

Jan 1, 2007

By V. A. Chanturiya, T. N. Matveeva, N. K. Gromova, T. A. Ivanova

"The research is aimed at solving the problem of increasing the extraction of gold from refractory ores, which are the main source of growth in gold production in the next decades. The purpose of the research is the development and scientific substantiation of the reagent modes for flotation extracting of gold from refractory ores using eco-friendly low-cost herbal modifiers (HM), providing increase in gold recovery and quality of gold concentrates. In the course of research laboratory techniques for the preparation of experimental samples of HM were developed, which included the sequence of operations of grinding Heraclium leaves and stems grinding, 2-stages extraction at a temperature of 50-60 °C, short-term ultrasonic treatment, filtration and subsequent unification of extracts. According to the developed method, the experimental samples of HM and conducted research were tested to analyze their sorption and flotation activity related to the extraction of gold from refractory gold ores.New data on adsorption and flotation properties of Heraclium stems and leaves extracts (HSE) in selective flotation of Au-sulfide minerals were obtained using UV-spectroscopy, scanning electronic and laser microscopy and atomic force microscopy. The dimensions and shapes of adsorbed hydrophilic films of herbal reagents were identified and mechanism of formation of stable insoluble compounds on the surface of minerals in flotation was explained.Research flotation tests carried out on samples of refractory gold ore of one of Russia deposits showed the possibility of effective use of herbal modifiers to improve qualitative and quantitative indicators of enrichment compared with the standard reagent regime. New reagent modes, using herbal modifiers in an amount of 5 to 10 ml of the extract (300 - 600 g / t, respectively) improves the quality of the concentrate: gold content attains 14.7 g / t, 1.34 times higher than in the baseline experiment and provides a gain of 3.13% extraction.The developed reagent regime with herbal modifiers is the author's original design, patented (patent of the Russian Federation) and have no analogues in the world of mineral processing. (Application number 2015116125 from 04.28.2015, ""The method of flotation separation of sulfide minerals using herbal modifier"", Russia). Actual application of new plant extracts as modifiers in flotation of sulfide minerals is the possibility of replacing of highly toxic chemical compounds by environmentally safe substances of plant origin. Implementation of the developed methods of extracting gold from refractory minerals with herbal modifiers will help to improve gold recovery at 3-5% and the quality concentrate of not less than 1.2 times, leading to higher productivity and a reduction of the negative man-made effects on the environment ."

Jan 1, 2016

By D. Kulchyski, R. Thibault, D. Lamoureux

"Mine tunneling applications are sensitive to the leakage and friction performance of ducting systems. Improvements in performance can help project economics through reduction in drift height, booster fan spacing, fan electrical power requirement, and deferral of ventilation raise construction. Semirigid plastic ducting has enjoyed significant adoption in mine tunneling in recent years. This paper explores technical properties and performance aspects of this relatively new material application.INTRODUCTIONUnderground mining projects are sensitive to mine development cost and schedule to meet first production—both of which are defined to a substantial extent by mine access construction. The very nature of mine access development requires driving accesses into new areas and even mechanized and automated tunneling methods require ventilation. Until underground airways are connected, allowing a flow-through circuit, ducted ventilation is required to establish ventilation within any single-access (i.e.: dead-end) heading. See Figure 1 as an example of ducted ventilation. Improving performance of ducted ventilation systems impacts project cost and schedule in several ways:For drifts whose height is defined by overhead clearance above haul trucks or tall equipment, smaller diameter ducting will decrease heading size.With higher ventilation flows, activities can be less ventilation-constricted; secondary headings can be worked without restriction, which improves schedule.Given the ability to provide more air for a given fan power, blasting gasses can clear the face and mine more quickly so crews can return to work more quickly - allowing higher advance rates.Lower electrical costs – both due to lower power consumed by fans and with the requirement for fewer electrical stations to power booster fans."

Jan 1, 2019

By D. Farrish, W. A. Grell

"IntroductionMost base metal mines sell their concentrate to a custom smelter. The two parties concerned therefore draw up a contract which would detail the conditions under which concentrate sales will take place. The contract will identify treatment and marketing charges (including escalations), deductions for metal losses in the smelter, pricing formula, timing of payments, penalties for deleterious elements, etc.An understanding of the smelter contract is important to the mineral processor, for it will determine how he operates the plant to maximize economic return.Description of Contract ClausesUsing copper concentrate as an example, the smelter contract generally contains the following three basic charges:I. Metal Deductions- as the smelting process does not recover all the metal contained;2. A Smelting Charge- expressed per ton of material to cover costs on the bulk material such as receiving, unloading, thawing in winter, sampling, roasting to drive off sulphur, smelting through the matte and blister stages to recover mostof the copper and precious metals;3. A Refining Charge- expressed per pound of copper.The following is a review in some detail of a number of clauses which could be considered typical of a treatment and marketing type of copper concentrate sales contract. Most normal considerations in an agreement could be covered by the following types of clauses.Terminology- covers definitions, units of measurement to be used (e.g. short tons, troy ounces, etc.), currency (Canadian dollars). The term ""unit"" may be defined - l OJo of a ton of concentrate, e.g. one unit of copper means 20 pounds of copper per short ton of concentrate."

Jan 1, 1989

By CIM CIM

Why Workplace Important! ?We need Diversity is to do more in the industry as a whole to encourage and support diversity. It has long been an industry of white dudes and we?re not going to survive if that?s how we continue to think.? ? Mark Scott, HR Superintendent, Vale Inco PURPOSE OF MINING FOR DIVERSITY ? Share best practices in the areas of HR Development ? Support industry in attracting, recruiting and retaining a diverse workforce ? Raise awareness of industry HR challenges and collaborate with stakeholders to develop sustainable HR practices

May 1, 2009

By F. A. Forward

"IntroductionTHE LYNN LAKE MINE, situated in Manitoba about 150 miles north of Sherridon, has been actively developed by Sherritt Gordon Mines, Limited, during the past seven years, resulting in the establishment of a proven reserve of over 14,000,000 tons of ore containing 1.223 per cent nickel, 0.618 per cent copper, and additional cobalt values. For many years, the Sherritt Gordon Company operated a copper-zinc-gold mine at Sherridon but, as this mine was approaching exhaustion and as it was proposed to use the mining and milling equipment to treat the Lynn Lake ore, a number of unusual problems were faced in transferring plant and operations from the one mine to the other, and particularly in preparing to undertake nickel production.Preliminary investigation showed that the ore could be concentrated by flotation to produce a copper concentrate containing 28 to 30 per cent copper with less than 1 per .cent nickel, and a nickel concentrate containing 11 to 14 per cent nickel, 0.3 to 0.4 per cent cobalt, and less than 2 per cent .copper, with high recovery of the three metals in .the concentrates. It was apparent that, initially, the copper concentrate could be economically smelted and refined in the usual manner. But as the nickel concentrate contained an insignificant amount of precious metals (less than 0.02 oz. per ton) and as .it had a much higher nickel content than comparable concentrates normally produced from sulphide ores, the selection of a treatment process and the location of a plant required careful study."

Jan 1, 1953

By V. Aprahamian, G. B. Harris, C. W. White, M. Tangen

"In 2005, the Royal Canadian Mint (RCM) commissioned a new silver electrorefining circuit. This circuit was intended to operate with a minimal electrolyte bleed for the control of copper. However, by the time of start-up, the levels of copper-rich silver doré to electrorefining had increased, and despite partial pyro-conversion in a small Top Blown Rotary Converter (TBRC), copper concentration in the silver anode still averaged 7.5%. This necessitated frequent replenishment of the electrolyte with fresh silver nitrate since copper displaced dissolved silver during electrolysis, and therefore requiring a robust copper bleed treatment step in order to maintain cathode silver flake purity at 99.99%. The originally-installed bleed treatment system could not meet the RCM’s needs. A thorough review of known technologies, however, did not indicate one capable of handling the copper load, and resulted, therefore, in the development of a novel copper hydrolysis approach for removal of copper as an insoluble basic nitrate salt, and recovery of the associated nitric acid for re-use in the circuit. Laboratory-scale trials showed reproducible results, and existing equipment was subsequently modified.INTRODUCTIONIn 2005, the introduction of a new silver electrorefining circuit at the Royal Canadian Mint (RCM) initiated changes in the way customer silver, collected from the gold doré circuit, was processed. These circuit changes were discussed in a recent paper (Aprahamian, 2015). A wastewater treatment plant had not been budgeted at the time, and this represented a significant constraint when considering the introduction of a wet processing circuit. After a review of various options, a turnkey silver electrorefining circuit was purchased from a European firm. Initially, enough cells were ordered to produce 2 million oz of fine silver (999), with the option to increase to 5 million oz. The selected equipment was based on a Moebius cell design combined with a silver grain pressure dissolver to produce make-up silver nitrate solution. Additionally, an evaporator/hydrolysis unit included in the package appealed to the Mint Refinery, on the basis that it offered a simple way to bleed dissolved copper in electrolyte without generating effluent."

Jan 1, 2016