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Adaptive processing is often related to the mineral composition of the mining block currently processed. The portions of waste, ore and secondary product minerals considered are always positive and typically sum to 100% (i.e. a composition). A typical solution to predict block averages of spatially dependent quantities would be block kriging. However, kriging is based on spatial correlations and it has been repeatedly shown that correlations of compositional data are spurious and blurred by the constant sum constraint. Aitchison (1982) proposed a general solution for compositional problems, based on transforming the compositional data to a set of logarithms of ratios of components, and analysing the transformed scores. The transform is chosen to be invertible to ensure that no information is lost in the process. This methodology avoids spurious correlation problems and ensures coherence between results obtained with different subcompositions. Pawlowsky-Glahn and Olea (2004) adapted the approach for point-support geostatistics, allowing the prediction of point compositions from spatially neighbouring data, without the artefacts induced by standard multivariate cokriging. Unfortunately upscaling the results of this approach with block cokriging is not straightforward, because of the nonlinearity of logratio transforms. Furthermore, we have to consider those nonlinearities created by the dependence on the block composition of extraction efficiency and processing costs of the possible processing choices. This paper proposes a solution for predicting the conditional expectations of the benefit of processing the block with each processing choice using geostatistical simulations of the local values of the composition and the resulting block integrals. The computation for a large number of blocks can be done efficiently using Cholesky decomposition. The approach also allows the calculation of prediction errors for expected compositions and expected benefit at almost no additional computational cost. Such compositional approach is necessary, for example when processing choices depend on proportions of certain minerals after other components have been removed; or if processing alters the composition in a multiplicative way, by partially removing a portion of some components.

Aug 1, 2013

By G. W. Harris, P. Mousset-Jones, J. Daemen

"To minimize ore dilution induced by blast movement in surface mines, it is necessary to quantify such movement. This will enable more accurate location of the grade boundaries beneath the surface of a blasted rock pile before excavation. A method has been developed and tested to accurately measure the direction and magnitude of subsurface blast movement. This technique uses a cesium vapour gradiometer and a real-time, differentially corrected GPS system to locate pre- and post-blast position of magnetically enhanced target objects placed within blastholes inside a bench. The procedure developed does not require the blasted rock to be disturbed, and the movement information is available within a sufficient time to allow for modification of the selective mining boundaries for each surveyed blast. It was found that the maximum depth of target detection was 18 m, with the overall accuracy being measured as ±1 m (horizontally) and ± 1.2 m (vertically). IntroductionOre dilution is a critical concern for many mining operations. In some instances, it may be the cause of considerable mineral loss. Where the mineralization is finely grained, sedimentary and disseminated in nature, and exhibits no clearly defined visual ore/waste boundary, there is a heightened possibility for ore grade dilution. In most modern open pit gold mines, it is economically desirable to minimize dilution in the production process through the practice of selective mining by defining pre-blast ore digging boundaries, called digging polygons, on the preblast bench area. The polygons’ positions are defined by sampling the production drill holes, with the resultant assay and survey data being used to estimate the areas of specified grade content within the bench. Once the ore is blasted in the bench, the pre-blast locations of these digging polygons are flagged as designated areas on the broken ore pile. The purpose is for the loader operator to be able to recognize which areas of blasted rock are to be sent to the appropriate processing facility or to the waste dump."

Jan 1, 2001

By C. Anderson, H. Huang, P. Miranda, E. Dahlgren, I. Chandra, M. Jeffrey

The latter part of the 20th century saw great advances in the treatment of refractory gold ores coupled with increased reliance on the use of cyanide for gold processing. Now, in many parts of the world, there is social pressure to limit or eliminate the use of cyanide. As well, treatment of some refractory ores or concentrates which have excessive cyanide consumption, gold cyanide pregrobbing or significant sulfide content remain difficult. This paper will outline the history of the development of alkaline sulfide leaching as an ancillary process to nitrogen species catalyzed (NSC) pressure leaching. Electrochemical fundamentals and the applicable thermodynamics of the alkaline sulfide hydrometallurgical system will be outlined. As well, examples of refractory gold recovery with alkaline sulfide hydrometallurgy such as an arsenopyrite gold concentrate application, a chalcopyrite gold concentrate application, a pregrobbing gold ore application, and a cyanide consuming gold ore application will be delineated in this paper.

Jan 1, 2005

By J. E. Rehder

IN A DISCUSSION of use of any material of ?construction in the mining industry, two points of view must 'be kept in mind - that of the producer or manufacturer of mining and metallurgical equipment, and that of the maintenance and operating staff of the mining plant. In the first case, the choice of material of construction is up to the manufacturer and the user of the equipment has little direct say in the matter. However, if materials are badly chosen and the equipment does not function properly, wears out rapidly, or costs too much, repeat orders ?will likely go to a different manufacturer, so that, in the end, the consumer or mine operator does have the final voice. In the case of materials for maintenance work and plant operations, however, .the mill personnel have direct control over purchases and it is then that a well-balanced knowledge of materials, their properties, and their costs, can be directly useful. With all materials of construction, the final criterion is unit cost versus service performance, so that the lowest possible total operational cost will be obtained. Sometimes this means using the cheapest material available, sometimes the most expensive, but in any case careful analysis of service performance, replacement cost, and material cost is essential to determining the material that produces lowest total cost.

Jan 1, 1956

By Horace Freeman

The sulphur consumed in Canadian pulp mills and acid plants is worth approximately three million dollars annually and amounts to one hundred and fifty thousand long tons, all of which is imported from the United States. Concurrently with a decline in the value of newsprint there has been a gradual increase in the price of this raw material. Most pulp mills in Canada are situated within reasonable distance of domestic pyrite deposits; nevertheless it has not yet been found possible to mine these deposits and utilize the contained sulphur in competition with the imported material. It is the purpose of this paper to elucidate the reasons therefor, and to describe? a commercial-scale experiment undertaken with the object of introducing a native raw material into the Canadian pulp industry on the purely economic basis. Reasons for the Preferred use of Sulphur The known sulphur deposits in the United States are very large, so that at least a twenty-year supply of this material is assured. It is recovered cheaply and in pure condition. Although large deposits of pyrite are known in Canada, nothing has yet been developed to compare in size, cost of mining, or purity with the United States material. It has been necessary to handle and transport more than two tons of pyrite to equal a ton of sulphur.

Jan 1, 1930

By X. Grant Chen, A. R. Farkoosh, M. Pekguleryuz

Nano-scale Al-(Fe,Mo)-Si dispersoids form during solution treatment in grain interiors (intradendritic regions) of cast Al7Si0.5Cu0.3Mg alloyed with 0.3Mo (wt.%). Unlike the Q-Al5Cu2Mg8Si6 and ?-Al2Cu age-hardening precipitates which coarsen resulting in loss of strength in Al-Si-Cu-Mg alloys, these Mo-containing dispersoids are thermally stable and retain their strengthening effect at elevated temperatures. Consequently, the age-hardened Al7Si0.5Cu0.3Mg0.3Mo (wt.%) exhibits high strength and creep resistance at 300 °C.

Jan 1, 2014

By F. Rosenblum, P. Spira

A laboratory test has been developed for assessing the patential hazard from self-heating of sulphides. The technique consists in measuring the rate of self-heating, from near ambient temperature, of a 1-kg sample in an insulated chamber controlled at standard atmospheric conditions. The rate of oxygen consumption is monitored simultaneously. The paper describes the apparatus and test procedure, and reports data on various ores and mill products. Tailings known to have caused problems underground when used as backfill have shown heating rates of over 3°C/h. A preliminary hazard rating guide for backfill based on the known behaviour of several sulphide materials is presented.

Jan 1, 1981

By John L. Bonus

"WITHIN THE BROAD PARAMETERS implied by the title of my speech, I propose to deal more particularly this evening with a subject the many aspects of which have constituted the essential elements of one of the main thrusts undertaken by the MAC in the past two years, i.e., to create among Canadians a much greater awareness of the importance of mining and to demonstrate to them what are the many and varied benefits they derive from mining activities across their country. In other words, MINING - WHAT IT MEANS TO CANADA.I also intend to discuss some aspects of government-industry relationships.I am very conscious of the fact that I am speaking to an audience made u in large part of experts in several fields of mining and exploration activities. They will be familiar with many of the points I intend to discuss. However, without in any way suggesting that familiarity breeds contempt, might I emphasize that even in this particular forum there is justification for reiterating some of our basic philosophies and suggesting ways whereby they might be better understood and promoted.Let us first summarize the present dimensions of the Canadian mining industry."

Jan 1, 1971

By R. Aubertin, G. Panneton, P. Donovan

The Detour Lake gold project is located in northeastern Ontario, approximately 300 km northeast of Timmins, within the Abitibi greenstone belt in the northwestern portion of the Archean Superior Province. Historically this greenstone belt has produced approximately 180 million ounces of gold, largely from narrow vein underground mining. The Detour Lake project is a site of extensive past exploration since 1974, as well as underground and limited open pit mining activity from 1983 to 1999. During this period, it produced 1.8 million ounces of gold. Underground mining focused on narrow vein conventional shrinkage and mechanized longhole stoping. After acquiring the property in January 2007, Detour Gold Corporation initiated a comprehensive drill campaign to define the potential for a large, open pitable, low-grade gold deposit. From 2007 to present, Detour Gold has completed over 500,000 metres of diamond drilling. A technical report completed in March 2011 defined an open pit mineral reserve of 14.9 million ounces of gold, which is Canada's largest undeveloped gold reserve. The Detour Lake project is currently in development and infrastructure construction of the mine facilities started at year-end 2010, after all the necessary Provincial regulatory permits were received. Gold production is expected to commence in early 2013. Gold mineralization at Detour Lake is associated with a large scale deformation zone (Sunday Lake Deformation Zone; "SLDZ") that occurs at the contact between the 2.72 Ga Deloro Group mafic metavolcanics and the 2.69 Ga Porcupine Assemblage metasedimentary and metavolcanic rocks. The bulk of the gold mineralization is found in the hanging wall of the SLDZ, which is associated with a stockwork of auriferous quartz veins that splay from a flexure along the deformation corridor. The mineralization forms a 200-350 metres wide auriferous corridor defined over 3 kilometres along the strike of the mafic metavolcanic assemblage, from surface to at least 1,000 metres depth. The richest gold mineralized zones are commonly associated with quartz veins with a strong biotite alteration and local zones of pyrrhotite-chalcopyrite-pyrite-gold enrichment formed during the deformation of the quartz vein system.

Jan 1, 2011

By Edmund C. Bovey

"AS I begin my remarks this morning, please let me say how honoured and gratified I was to receive your invitation to address you here during your deliberations in historic Quebec City. The high esteem in which your Institute is held is reflected in the respect and deference accorded to it by industry across Canada. I feel privileged to be here with you today.I would like to discuss with you some applications of natural gas in the mining industry and suggest to you, in closing, some possible avenues of future development.Natural gas first became avail-able for industrial purposes in Northern Ontario in late 1958. Acceptance of natural gas, as a source of energy by the industry of that area, has been both widespread and gratifying. The mining industry of Northern Ontario has in-creased its annual use of natural gas by approximately 35 per cent each year since 1958. We believe that this trend will continue, al-though we will probably have to accept a more modest 10 per cent annual gain as the market approaches saturation. I would like to explain how we were able to do this and where all this gas is used. Our first sales were largely a matter of price-and the savings we offered were substantial."

Jan 1, 1966

By H. B. Lumsden

This paper is intended to deal merely with the commercial development of some of the principal non-metallic mineral resources in the three prairie provinces- Manitoba, Saskatchewan, and Alberta. Coal is not included in this summary. Building Stone First and foremost, mention may be made of the building stone now being produced at Tyndall, Manitoba. This is a mottled limestone and is declared by experts to be one of the finest building stones in America, both as regards durability and appearance. It has been used very extensively both for exterior and interior work, not only in western Canada, but also in the principal cities as far east as Montreal. The stone is the "'Upper Mottled Limestone", which forms the summit of the Trenton (Ordovician) strata in the Lake Winnipeg basin. Quarries are at present being operated at Garson and Tyndall . The area where this stone is known to be available extends in a north and south direction for a distance of three miles, and the main productive ridge is probably about one half mile wide. The outlook for the future of the industry is extremely promising, as the stone is becoming increasingly popular in Eastern Canada, more particularly for interior work.

Jan 1, 1928

By R. D. Brown

In view of the many changes which have taken place since 1950 in the rules of the Income Tax Act concerning the deduction of exploration and development expenses, many corporate taxpayers each year face the tedious task of determining which particular rules their unclaimed exploration and development expenses are subject to and in what sequence these expenses are to be claimed. Recent amendments to the Act have cleared up some of the mystery of the "ordering" of these deductions. This article examines the sequence in which various categories of exploration and development expenses are to be deducted in accordance with the terms of the Act as amended by Bill C-11.

Jan 1, 1978

The Rabbit Lake In-Pit Tailings Management Facility contains frozen layers of tailings due to subaerial deposition during the coldest periods of winter. Thawing is required to ensure full consolidation of the tailings and to regain disposal space presently occupied by ice. Electric resistance heating has been used to heat soil for bitumen extraction and remediation of volatile contaminants. A preliminary evaluation of the application of electric resistance heating to thaw about 0.3 cubic metres of frozen tailings was conducted using tailings frozen at about -2 oC. Visible thawing of the tailings mass was observed after 25 hours, demonstrating the feasibility of this approach.

Aug 1, 2010

By X. Wu, W. R. Chen, J-G. Legoux, B. R. Marple, E. Irissou

Cold gas dynamic spray (CGDS) has been considered a potential technique to produce the metallic bond coat for TBC applications, because of its fast deposition rate and low deposition temperature. This paper presents the influence of spray processes for bond coat, including air plasma spray, high velocity oxy-fuel, and in particular CGDS, on the oxidation performance of TBCs with a Co-32Ni-21Cr- 8Al-0.5Y (wt.%) bond coat. Oxidation behaviour of the TBCs was evaluated by examining the coating microstructural evolution, TGO growth behaviour, and crack propagation during thermal exposure at 1050°C. The relationship between the TGO growth and crack propagation will be discussed.

Jan 1, 2010

By L. Tikasz

The primary purpose of ore hauling model studies is to capture the variability of the ore delivery ? stockpiling process in order to improve the estimation of equipment capacities and achievable throughputs. The operation of a mine-to-site ore delivery system is the subject of a number of challenges. Typically, ore is hauled by a given combination of trucks, conveyors and trains. In addition, ore loading, ore transferring to another means of delivery, stockpiling, reclaiming, and further deliveries involve many other types of equipment. The concurrent operation of all these units is scheduled; nevertheless, they are subject to planned maintenance and random breakdowns. To support our engineering design work on ore hauling operation, discrete event type models were built for each specific task. Then, due to recurring demands, an ore hauling library was gradually compiled. The now available model library allows fast and efficient simulation of various mine-to-site hauling arrangement, adaptable to various mining and mine construction operations (e.g. bauxite, iron ore, copper ore and coal).

Aug 1, 2013

By George Brien, O&apos

The history of the lighting of mine workings dates back to the early part of the 18th century, when small candles known as tallow dips, were used. These were set or held in a lump of wet clay. When looking for gas the flame of. the candle was reduced to a mere glimmer by surrounding the wick below the flame with clay. The candle was then very cautiously raised from the floor toward the roof, the observer screening the brighter portion of the flame with his hand and watching for the first appearance of the pale blue cap above the flame, even at that time, known to indicate the presence of gas. When this appeared the candle was lowered quietly and its flame extinguished before attempting to drive out the gas. A very common and dangerous practice adopted at that time was to get rid of the gas by firing it. This was done by a person selected for his nerve rather than for his caution. Dressed in a? suit of dampened sackcloth or leather, this man well termed a "fireman", would lie prone on the floor of the roadway and light the gas above him by raising his candle fastened to the end of a long stick. If he survived, which was not always the case, he would withdraw promptly to fresh air after the flame had passed over him.

Jan 1, 1924

By K. C. Corin, M. S. Manono, J. G. Wiese

Depressants play a crucial role in the flotation of PGM bearing ores as they prevent naturally floatable gangue (NFG) from reporting to the concentrate. This action is regarded as critically important because less dilution of the concentrate means lower costs for downstream processes. However, abnormal water conditions (such as high concentrations of ions) in the flotation system can modify the selectivity of these depressants. It is well known that the existence of selected electrolytes in water can alter the behaviour of some polysaccharide depressants by enhancing their adsorption onto gangue minerals and thereby prevent naturally floatable gangue from moving into the froth phase. Concurrently these same electrolytes may enhance frothability, owing to their stabilising effect on the bubbles within the system. Plant water at various ionic strengths was investigated against depressant type and dosage in order to understand electrolyte-depressant interactive effects during the flotation of a Merensky ore, using entrainment, rate of NFG recovery, and total gangue recovery as proxies. The study showed that the rate of NFG recovery per unit mass of water decreased with increasing ionic strength at all dosages, however the total amount of gangue reporting to the concentrate increased with increasing ionic strength at all depressant dosages. Thus, this paper attempts to consider the effects of both ionic strength and depressant dosage as individual factors within flotation. It further looks to investigate whether any interactive effects exists between these two factors when considered simultaneously.

Jan 1, 2016

By A. Desbiens, M. Maldonado, R. del Villar, Aguilera. R.

This work details the application of a multiple model approach to estimate frother concentration in flotation processes. The methodology consists of identifying a set of linear dynamic models representing the effect of gas rate on the collection-zone gas holdup at different known frother concentrations (calibration step). An adaptive law is then obtained using Bayes' rule to evaluate the conditional probability that each model represents the observed system behavior. In this way, a frother concentration estimate is calculated as a weighted sum of model probabilities and their associated (known) frother concentrations. Experimental results conducted in a two-phase system using Dowfroth250C are promising. Modeling and analysis for MIBC frother are also provided.

Jan 1, 2009

By K. W. Major

"This chapter outlines the organization of mine/ mill complexes in Canadian mining companies. Many factors unique to the Canadian mining industry will affect the design of the organization in the future: geographic location, the size and the type of orebody, etc. Mining companies cannot choose where new operations will be located, that is dictated by the location of the orebody. New mines are seldom started near established communities. Rather, the towns usually grow up near the mines. The remoteness of most Canadian mining operations has caused severe problems in attracting and/ or retaining all levels of employees. This means that training has a high priority within each operation.Another factor affecting mine/ mill organizations is the size of the operation. Larger operations generally require more departments and increased specialization to manage equipment and manpower effectively. Thus, for mine/mill complexes, organizational charts are less standardized than in other industries. It is often necessary to organize around the work force rather than develop a chart and then acquire the trained personnel to fill the diagrammed positions.The information presented in this chapter has been derived from the responses received from a survey of Canadian mining operations.Principles of OrganizationOrganization can be defined as deployment of personnel to accomplish definite goals. In the mining industry, the major goals are typically the projected number of tons and grade of ore mined on a daily, weekly, monthly and yearly basis. Organizing involves establishment of authority relationships with provisions for both vertical and horizontal co-ordination within the company structure. Vertical co-ordination is the delegation of responsibility and communication of goals and reporting of progress between the supervisor and subordinate. Horizontal co-ordination is communication between departments at positions of equal authority to determine methods of achieving predefined goals. The organization structure must reflect the objectives and plans of the company, and must clearly define areas of authority.Two criteria for effective organization are departmentalization and manpower planning."

Jan 1, 1989

By C. Yoo

"Geosynthetics engineering has made phenomenal advances during the last decade in areas of manufacturing as well as practical applications. As a result, geosynthetics are now being recognized as essential construction materials that can be used to facilitate construction, ensure better performance of the structures and reduce the long-term maintenance in routine civil engineering works. The creative use of geosynthetics in geo-engineering practice is expected to continuously expand as innovative materials and products are becoming available. In this paper, a wide variety of geosynthetic products available to geoengineers to solve a wide range of problems are briefly presented along with their functions and possible applications. Fundamentals of geotextile filter design principles are then introduced for use in the tunnel drainage system. Practical applications of geosynthetics relevant for tunnel engineering are also highlighted with emphasis on the issues associated with the geotextile filter application for use in the tunnel drainage system.INTRODUCTIONGeosynthetics have emerged as essential engineering materials in a wide range of civil engineering applications, e.g., transportation, geotechnical, geoenvironmental, hydraulics, and private development since the first geosynthetic conference in Paris, 1977 (Koerner 2012). Due to their costeffectiveness, ease of installation, and well established mechanical and hydraulic properties, geosynthetics are now playing important roles in the field of geo-engineering.As indicated in the 9th Bucahanan Lecture paper by Holtz (2001), major developments in civil engineering have only been possible with the parallel developments in the technology of construction materials. For example, larger scale structures became possible with the help of developments in concrete, reinforced concrete, and prestressed reinforced concrete technology which replaced wood and building stone as construction materials. The best example of a parallel development in geo-engineering between the material and the geotechnical application may perhaps be the soil reinforcement technology which has a direct analogy with reinforced concrete as a polymeric reinforcement material provides added level of tensile resistance and stability to soils that have little to no tensile strength, thus giving additional margin of safety."

Jan 1, 2015