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By R. D. Brown

In the spring of 1977, Revenue Canada announced its intention to proceed in 1978 with a plan to impute a taxable benefit on interest-free and low-interest loans provided to employees. Such loan arrangements are often an important aspect of the compensation packages provided by many companies to their employees. Since the original announcement, there have been many submissions to Revenue Canada opposing this change, and the Finance Minister has now brought down a compromise solution with the introduction of a proposed amendment to the Income Tax Act. The amendment, which would not take effect until the 1979 taxation year, would require an employee, a shareholder or a related person to include a benefit in income measured as the difference between the interest on any such loan computed at bank prime rate and any interest actually paid. Only the amount of such a benefit in excess of $500 in a particular year would be required to be included in income. Of particular interest is the exclusion from these benefit rules of loans up to $50,000 in respect of the purchase of a house on the relocation of an employee and loans provided for the purchase of shares of an employer corporation.

Jan 1, 1978

By A. Christoffersson, T. Nillson-Wullf, H. R. Manouchehri

"Mining industry has been the building blocks for human development through millennia and will continue to play its role in sustainability and meeting society’s needs for raw material. In the way towards sustainability, the next generation of efficient and heavy duty of Sandvik’s crushers, CH860 and CH865, are introduced for efficient crushing. As the secondary, tertiary and/or pebble crusher, these new crushers are designed to over perform in tough mining environment. Featuring higher crushing forces relative to the mantel diameter and 500 kW motor, combined with advanced automation system, i.e., sophisticated HydrosetTM and Automated Setting Regulation (ASRTM), combined with overpressure system with dedicated air supply in dust collar, etc., the new crushers provide higher safety, productivity, and reliability with the same foot-print of conventional cone crushers.Since crushers are more energy efficient than mills it makes sense to effort in fine crushing to save energy and protect environment. That has been the logic behind development and introducing stronger and more efficient crushers by Sandvik. The results on crushing hard iron and gold ores by CH865 have proven its efficiency in fine crushing at a higher productivity, availability and reliability rates through increasing throughput for defined size fraction and extended crushing chamber liner life.Within this paper the performance of the CH865 to deal with two different ores are presented discussed with a glance at how the downstream milling process can be benefited by saving energy and reducing the operation cost. In plant practice, the implementation of the new CH865 provides between 25 and 30% of the crushed ore in the size range of first step milling, i.e., < 2 mm, that offers opportunity for reduction in energy consumption in milling and even changing the process plant configuration by directly forwarded that part to gravity separation. Furthermore, potential of converting the rod mill to ball mill to improve productivity has been considered by plant engineers. Furthermore, some potential applications for such efficient crushers are brought into considerations and discussed. The new developments provide about 30% higher crushing force to efficiently deal with competent ores and pebbles. The CH860 and CH865 crushers are well suited to replace conventional secondary and tertiary crushers respectively; nevertheless, CH865 is virtual option for pebble crushing in SAG and AG milling circuits."

Jan 1, 2016

By T. B. Armstrong

"The energy situation is extremely fragile and there is a critical need for energy conservation in the short term and development of new technology in the long term. To keep tabs on energy flow, separate electrical metering is being installed in major industries: The first step reduces demand through peak load control; the second reduces the waste of energy by monitoring energy used per unit of production. IntroductionThe current energy situation is best described as being extremely fragile. The supply of hydrocarbons is being exhausted, while energy needs remain the same in the industrialized nations and are increasing in the Third World.The petroleum era is expected to come to an end in this century, as there will no longer be enough. Gas, coal and electricity will replace some oil as it becomes scarcer during the transitional period before new sources are gradually developed.There is a critical need for energy conservation in the short term. Conservation will, to a great extent be justified by savings, as it will be less expensive to recover energy that is being wasted than to acquire additional energy.The gradual development of new technology is expected to increase energy self-sufficiency in the long term. New energy sources are attracting a growing interest and are becoming more economically feasible and marketable. These rediscovered energy sources include peat, wood, solar, domestic waste and windmills.The sudden increase in energy prices has forced users to look at the way energy is used and find ways to save it. Major industries have found that using separate meters for each department spurs energy responsibility. Energy trim programs now rank in importance with profitability, productivity and with quality.Energy has become such a crucial cost element that better data are essential for planning. Data acquisition varies with plant size and number of utilities. Meters can be read manually or monitored by computerized energy management systems.The relationship of electrical energy input and production levels for a typical uranium mine will be used to demonstrate two steps to energy management. The first step reduces demand through peak load control; the second reduces the waste of energy by monitoring energy used per unit of production.The direct benefit of saving energy is the money saved."

Jan 1, 1980

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 L. S. Almeida, U. A. Courbassier, C. T. Guimãaraes, M. N. Souza, V. L. Silva, H. P. Dias, G. A. Bicalho, B. S. Rocha, P. N. Rodrigues, A. Carnevale

During primary aluminum production the anode changing is a very important task. So improvements on it will be essential to avoid disturbance and have a better operational control. After anode changing a good current distribution will be guaranteed using a cavity cleaner and precise anode setting. Albras switching a manually anode setting to an automatic one solved the setting problems. In this paper it will be shown some pot line results and the improvements on workers ergonomic and safety conditions. The device was developed in a partnership between Albras and Pesto.

Jan 1, 2006

By N. Ogbonna, D. G. Dixon

Although heap bioleaching has been recognized as an economic alternative for treating low grade mineral ores, the underlying physical, chemical and biological processes involved are complex. A detailed investigation into the dynamics of heap bioleaching processes has provided much insight into the underlying complexities, and has led to the development of a sophisticated modelling tool - HeapSim. This tool can be of great help in the design and operation of heap bioleaching processes. In this paper, the mathematical model implemented in HeapSim is examined. The model takes into account mineral kinetics, particle level effects, bacterial growth, oxidation and adsorption, gas absorption, pore diffusion, bulk advection, gas balance and heat conservation. Three case studies where the model has been applied are briefly discussed. Computational Analysis in Hydrometallurgy 35th Annual Hydrometallurgy Meeting held in conjunction with the 44th Annual Conference of Metallurgists of CIM Calgary, Alberta, Canada Edited by

Jan 1, 2005

By S. Caron

From the early 70?s, ?Centre de Recherche Minérale? (CRM) has conducted and co-ordinated Research and Development activities for the mineralurgical and metallurgical industries. Since 1999, CRM has continued its mandate through COREM which is a consortium of 13 members that uses the benefits and advantages of collaborative pre-competitive industry / university research. In particular, COREM?s ?In-Situ Optimization Group? is involved in the implementation of modern optimization and control tools. The POP Project was launched in order to increase and consolidate the use of modern optimization and control tools and methods for mineralurgical and metallurgical processes. To ensure a successful transfer in the industry, there are a number of essential activities that have to be undertaken. These activities have been identified by COREM?s members and are grouped into three main modules: - R&D Module: Research and Development in universities, research centres and other partners; - Technology Transfer Module: integration of new tools and methods into the POP Software, industrial applications and technical support; - Training Module: education of new engineers in universities, continuing education of plant personnel through on-site workshops and resource networking by specific information exchange tools. This paper outlines the opportunities that led to the definition of the POP Project and describes its main modules. The main features of the POP Software are presented, the first application is described and finally, future developments are discussed.

May 1, 2001

There are many inherent risks in creating a mine plan for a new ore zone in an underground mine; one of such risks is the redistribution of stresses that could be a cause of instability. Using numerical modelling tools, it is possible to model the planned stope extraction sequence and evaluate the influence of mining induced stresses on the stability of remnant pillars, and use this information to remedy potential setbacks. This paper demonstrates this approach through a case study of the short-term mine plan of the Lapa mine of Agnico Eagle Mines Ltd., an underground gold mining operation near Val d?Or. Three-dimensional boundary element modelling is used to compute the stresses induced by the stope extraction sequence as planned with a longitudinal retreat mining method. The proposed methodology can be generalized to other mines that require an understanding of the stress concentrations at the pre-feasibility stage of mine design.

May 1, 2009

By A. Ingelson, C. Nwapi

"With growing international interest in mineral resources in Central Africa, the importance of transparency in resource development cannot be overemphasized. Without transparency, the region cannot maximize revenues from resources. Although the importance of transparency is beginning to be recognized, many factors can hold back the gains of transparency from resulting in real economic development for the countries involved. This paper reviews current financial, economic, and development literature for Central African countries, with a focus on identifying underlying conditions and specific transactional conditions impacting the effectiveness of transparency in mining development in the region.RÉSUMÉ En raison de l’intérêt international croissant pour les ressources minérales en Afrique centrale, l’importance de la transparence dans le développement des ressources ne peut pas être surestimée. Sans transparence, la région ne peut pas maximiser les revenus tirés de ses ressources. Bien que l’importance de la transparence commence à être reconnue, plusieurs facteurs peuvent freiner les gains acquis de la transparence à produire un véritable développement économique pour les pays touchés. Le présent article analyse la littérature financière, économique et développementale contemporaine pour les pays de l’Afrique centrale, tout en ciblant l’identification des conditions sous-jacentes et les conditions spécifiques transactionnelles qui ont un impact sur l’efficacité de la transparence dans le développement minier de la région."

Jan 1, 2015

By M. Marchese

It is no secret that scarcity of fresh water is an issue that at a global level in the years to come will have a major impact on the business landscape. A number of projects, beyond the mining sector, could remain on paper only due to this. At the same time, this situation is seeing the rise of new business opportunities, such as development of technologies for more efficient usage of water, water recycling, and desalinization of sea water. Despite that most of Chilean mining facilities are located in the driest area of the world, business has developed strongly and actively for more than a century. However, the negative effect on the water reservoirs and the environment is, lately, resulting in the reduction of the authorized water rights. Holding Water Rights for any given volume does not guarantee that the resource will be available when needed. A recent report from the United Nations on global climate change indicates that global warming can be directly related to changes in the natural and human environment. Chile would not be an exception. The reduction in snow levels in the high Andes and reduced rainfall during the so called "Bolivian winter", have directly affected the replenishing of the underground water reservoirs in the lower parts of the valleys, where most of the extraction of the resource takes place. Mining facilities shall be designed to reduce potential environmental effects, using proven technologies, and considering the best practices available. These measures shall constitute a complete structural framework for the environmental impact assessment (EIA) of the Project. The measures to prevent and mitigate the impacts on the water resources shall be considered during the design stage of a mining project. Current and future mining projects in Chile are conscious that the increasing pressure on the limited water resources is becoming unsustainable, and are already facing the water scarcity and social pressure by implementing sea water desalination plants, including long pressurized pipelines to the mine sites (e.g. Escondida, Candelaria, El Morro, Regalito). This paper presents, in summary, an analysis of the present and potential future scenarios.

Jan 1, 2007

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 H. Tudeshki

A great amount of aggregate is utilized in civil engineering applications such as road construction, railway infrastructure, concrete production, etc. Igneous rocks are the preferred raw material due to their high strength and abrasion resistance. Rock quality assurance is a key factor and has great influence on the quality of constructions in civil engineering. One of the major problems encountered by both the producers and users of igneous aggregate rock is the fact that, with the passage of time, some specific rocks lose their strength, up to a complete loss of structure, i.e. disintegrate and degrade. This phenomenon has a great influence on the quality, strength and durability of aggregates. In the last decades, different methods and procedures such as the glycol test, the methylene blue dye test, as well as the Los Angeles test, have been introduced to distinguish rock properties, and to identify these problems. However, as these wet-chemical methods are time consuming, hard to perform, only to be applied to hand-piece samples, requiring special laboratory equipments, and are only possible to be accomplished under laboratory conditions, their application has always been severely limited. To address this widespread quality management problem of the quarry industry, a relatively quick, easy and user-friendly approach is necessary. It calls for a systematic solution with a device that can simply be used in the day-to-day routine of a mine for quality control of the quarry´s daily production. Our research is concentrated on developing a systematic method for early recognition and diagnosis of rock quality, in order to control and manage the quality of the quarry production in advance. Our new approach is based on two rock parameters: magnetic susceptibility and loss on ignition. The measurement of these parameters provides reliable information on the quality of the rock and allows the quality control process to be accomplished and performed at the borehole location. Our new approach has been assessed through extensive field and laboratory studies and has been implemented on the drill-cuttings of a basaltic andesite quarry. The results of the experiments are discussed in detail, including their impact on increasing resources and environmental protection.

Aug 1, 2013

By E. G. Bazeley

The paper reviews the scope, timing and financial impact of this significant project, which involves the supply and transportation of nearly 4 million tons per year of bituminous coal and lignite from sources in British Columbia. Alberta and Saskatchewan to Ontario Hydro&apos;s generating stations. The critical factors involved in the selection and utilization of these coals are discussed in relation to the three types of coal to be utilized initially. The paper then deals with each of the significant project elements to be undertaken by the various companies involved in the mining and movement of the coal, beginning with production at the mine through rail shipment to Thunder Bay, train-to-ship terminalling, shipment by lake vessel from there to the generating station, and finally blending the bituminous coal with United States coal prior to combustion. The review discusses the key features of the facilities involved in each case and the status and timing of the project elements , which are phased for the start of coal shipment by mid-1978. The paper concludes with some observations on the capability of the project to handle increased tonnage s and the challenges facing the movement in terms of quality , quantity and cost.

Jan 1, 1978

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

By D. M. Baird

Copper mineralization occurs at several places along the shore of Notre Dame bay, Newfoundland, and at one time formed the basis of a considerable mining industry. The sources of the mineralizing solutions and the structural settings of some of the deposits have not been clearly understood. This paper reports new investigations into the origin and structure of the deposits between Bett&apos;s cove and Stocking harbour, in a strip about ten miles long and two miles wide along the western shore of Notre Dame bay. The most complete previous descriptions of the area are those of Snelgrove (1929, 1931, 1938), Douglas, Williams and Rove (1940), and the writer (1947). The discovery of the Bett&apos;s Cove deposits took place about 1860, soon after the discovery of the well-known Tilt Cove deposits to the north. Several other small prospects were found between Bett&apos;s cove and Stocking harbour between 1880 and 1910. At Bett&apos;s cove, active mining began in 1875 and a small smelting plant was built near the mine in 1877. .Mining operations came to an abrupt halt in 1883 after a major cave-in. In 1900, and again in 1906, attempts were made to drain the old workings and reopen the mine but were abandoned long before completion. Total production amounted to about 130,000 tons of hand-picked copper ore which averaged about ten per cent copper, and 2,450 tons of pyrite (Snelgrove, 1938, pp. 52-55).

Jan 1, 1948

By Steve T. Laflin

Since the beginning of the nuclear era, there has never been a commercial solution for the large quantities of depleted uranium hexafluoride generated from uranium enrichment. In the United States alone, there is already in excess of 1.6 billion pounds of DUF6 currently stored. INIS is constructing a commercial uranium processing and fluorine extraction facility. The INIS facility will convert depleted uranium hexafluoride and use it as feed material for the patented Fluorine Extraction Process to produce high purity fluoride gases and anhydrous hydrofluoric acid. The project will provide an environmentally friendly and commercially viable solution for DUF6 tails management.

Aug 1, 2010

By Manqiu Xu, Songtao Yang, Zongfu Dai, Robert Pelton

Five years ago, VALE Base Metals (then INCO), approached Pelton&apos;s group at McMaster and described a challenging mineral separations problem. The McMaster group has a strong track record in colloids, polymers, and chemical additives for papermaking; however, they had no experience in mineral processing. They proposed employing hydrophobic nanoparticles to replace conventional low molecular weight, water-soluble flotation collectors. Over the last five years, Vale, together with the Ontario Government (OCE) have funded two graduate students at McMaster who have worked closely with flotation experts at Vale. Experiments involving both very clean model mineral suspensions at McMaster and complex ores at Vale, have shown that hydrophobic nanoparticles do indeed function as collectors. Key nanoparticle properties and mechanisms have been identified and the technology has been protected in patent applications. Efforts to commercialize the technology are on-going. We believe that this project is a good case study demonstrating the advantages of industry-university collaboration and the use of outside experts, who may come up with novel solutions to complex problems.

Jan 1, 2011

By Zainelabdin Khalid Zainelabdin Elfaki

The influence of partially replacing cement with marble waste on the workability and compressive strength of concrete bricks was investigated. Three replacement percentages, 10%, 20% and 30% weight marble waste, were used with different curing times of 7, 14 and 28 days. Two specimens were prepared for each percentage and curing time. For this study, marble powder from the Mining House Company in Saudi Arabia was used. It was observed that the replacement of cement in Concrete brick with marble waste enhanced the loading strength and the workability of the prepared concrete bricks. It was also observed that 20% replacement of cement with marble waste was the best replacement percentage compared to the other replacement percentages tested. Marble waste from manufacturing companies, either in powder, sludge or slab form, has negative impacts on the environment. In contrast, reusing marble waste has both economic benefits (i.e., selling the marble waste) and lessening the need for raw resources.

Jan 1, 2014

By A. C. Munro

The concrete work on the new Britannia mill was started in April, 1922. The erection of steel commenced on July 10th, following. The installation of wood work and machinery , began on November 4th of the same year and was pushed to completion in January, 1923. The new mill building is an all steel structure enclosed with galvanized corrugated steel. All main floors and foundations are of reinforced concrete, which makes the building practically fireproof throughout. The mill building rises on a steep hillside to a vertical elevation of 210 feet and has seven distinct floors, for the various opera-tions. Only one elevator, with 30-foot centres, is used in the entire mill. The building is exceptionally roomy and well lighted, both by day and night. The capacity of the mill, as originally designed, was to be 2000 tons daily, but this tonnage can be readily increased to over 3000 tons daily by making slight changes in the fine grinding equipment; in fact, an average of 2700 tons per 24 hours was maintained throughout the month of September.

Jan 1, 1923

By E. Rosseland

Glencore Nikkelverk is operating its Chlorine Leach Process in Kristiansand, Norway, producing nickel, copper and cobalt metals by electrowinning. The copper tankhouse, with an annual capacity of 40 000 tons, is based on traditional technology with copper starting sheets and cast lead anodes. Due to the integration of this copper sulphate process in a nickel chloride refinery, operating conditions are unique. In recent years, operating costs have escalated, and health, safety and environment are top priorities. Test work on a new copper process involving permanent cathodes was therefore initiated in 2007, and a pilot plant was started up in 2012. The objective was to introduce innovative technologies and tailor these to be robust in the Nikkelverk process, to form a basis for a new sustainable copper tankhouse with a high degree of automation. Key learnings from more than 10 years of R&D work is presented, focusing on cathode materials and copper metal deposition including product quality, robotic stripping, coated titanium anodes, electrode contacts and alignment, electrode current monitoring with Hatch HELM tracker technology and acid mist capture using cell hoods with off-gas scrubbing. The new copper tankhouse project was approved in December 2018, and commissioning is planned in 2022. INTRODUCTION The Kristiansand nickel refinery was started up in 1910, processing nickel-copper matte originating from Norwegian mines. It was the first industrial plant in the world to produce nickel by electrolysis using the Hybinette electrorefining process. After roasting to burn off sulphur in the matte, copper was leached and recovered as cathodes by electrowinning with lead anodes. In the first years, the copper cathodes were fire- refined and cast into ingots for sale (Thonstad Sandvik, 2004). The Nikkelverk refinery was acquired by Falconbridge Ltd. in 1929, and since then matte from Sudbury, Canada has been the main feed source. The Hybinette process was in operation until 1975 when conversion to the newly developed Chlorine Leach Process was started (Stensholt, Zachariasen, & Lund, 1986). In this process still used today, nickel and part of the copper in the matte is leached using chlorine gas generated on dimensionally stable anodes in the nickel and cobalt electrowinning tankhouses, as illustrated in Figure 1. The presence of dissolved copper ions in the strong chloride leach solution is essential for effective chlorine absorption and nickel dissolution. To improve copper-nickel separation, slurry from the atmospheric leach is pumped to autoclaves and then to cementation tanks for precipitation of copper as copper sulphide, which is collected in filter presses. The leach residue, also containing the precious metals, goes through a 3-stage wash to remove chlorides before being introduced as a slurry to fluid-bed roasters for sulphur removal. The resulting calcine is then leached in spent electrolyte from the copper electrowinning tankhouse, to dissolve most of the copper and also some nickel, cobalt and other elements. After separation of the leach residue, elements like Bi, Te, As and Ag are removed from the strong copper sulphate solution by reaction with metallic copper in three columns in series filled with cut copper cathodes. The purified solution then passes polishing filters before being mixed with spent electrolyte and returned to the electrowinning cells.

Jan 1, 2019