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By P. D. Duever, P. J. Readyhough, P. L. Silveston

"The Plastojrost apparatus, developed by Ritter and Juranek in the 1960s has been modified primarily, to automatic temperature control. A limited investigation of carboniferous and cretaceous coal samples showed that both coals undergo the same changes when coked in the Plastofrost unit. Dilatometer plastic range and total dilatation correlated well with the Piastofrost plastic range for the carboniferous Appalachian coal, but not for the cretaceous western Canadian coal. Work to elucidate the characteristics of some western Canadian coals using the Plastofrost is in progress. IntroductionCoke quality is critically affected by the properties of the plastic phase in the coal-to-coke transformation. Since these properties exist in a coke oven and are not measurable, they are approximated by standard laboratory tests, such as free swelling index, plastometry, and dilatometry. Of particular interest to us is the anomalous behaviour of western Canadian coals of cretaceous origin. By many predictive methods, these coals should not produce coherent cokes. When coked in pilot scale test ovens, in fact, they produce cokes of good stability. They typically make up 20% of Japanese coking coal blends and are also used in South Korea, Mexico, Brazil, and several European countries. This anomalous behaviour has been studied in our laboratory<8.9.1O). Plastic properties or rheological tests examine just the external ramifications of the coal-to-coke transformation. To understand the process, however, microscopic examination of the coal and coke seems to be needed. The Plastofrost unit has been shown to be a convenient means to this end."

Jan 1, 1987

By D. S. Harries, R. I. L. Guthrie

"The use and development of scientific disciplines involved in heat transfer technology, related in general to steel masses and in particular to batch annealing, is demonstrated.The measurable benefits of cooperation are tabled; on industry&apos;s side, this includes a 10 to 20 per cent decrease in annealing time, and a corresponding higher productivity potential. The returned benefits to the academic engineer include the development and refinement of new computer algorithms related to heat transfer mechanisms.IntroductionThe object of this discussion is not really to describe an improvement in the batch annealing operation, but to use the project as an example of joint work between industry and the academic field. Both parties have derived a number of substantial benefits. These benefits will be listed, of course, but the batch anneal project will be used just as a typical example of cooperation. Why it happened will be explained, what actually happened will be described and finally some thoughts about areas in the field of heat transfer, where cooperation will continue in the future, will be highlighted. The paper will close with a message.Industry OverviewAt the outset, perhaps it should be understood that, in general, the Research Department at Dofasco believes that the universities and their staff are not destined for the problem-solving role in industry. Its opinion is that the university staff is best suited to the gathering and dissemination of knowledge. There are other more professional problem solvers for industry, including the steel industries&apos; own individual investigation groups. Dofasco, therefore, looks to its academics for consultation. It benefits by bouncing ideas off them, and through rubbing shoulders with them in such a way that their knowledge can be tapped, and thus establish more effective scientific routes. In addition, the younger and brighter engineer s can broaden their scope through the intellectual contact with experts. The university professors can, it is believed, benefit through closer contacts with result-orientated research. They can also develop an appreciation of the fiscal control necessary for industrial investigations, without government subsidies, grants, etc., and with massive overheads."

Jan 1, 1982

By Mario E. Rossi

Geostatistical conditional simulations are becoming increasingly popular as tools that provide models of uncertainty at different stages of a mining project. They have been used as grade control tools in daily operations, to assess the uncertainty of minable reserves at the project?s feasibility stage, and to assess mineralization potential in certain settings. Other applications include assessment of recoverable reserves, resource and reserve classification, and drill hole spacing optimization studies. All large-scale applications of conditional simulations intend to benefit from the ?correct? (or ?accurate?) characterization of uncertainty, adequately describing the variability observed from the data and its impact on the final objective. The objective of this paper is to compare the ad-hoc ?uncertainty model? provided by a traditional classification scheme with the probability intervals resulting from a conditional simulation model. It is argued that the uncertainty model derived from the use of classification schemes is of little practical use to the mining company or operation. The paper emphasizes differences in uncertainty based on the size of the mining unit considered and the extraction method, and local geological differences. Most importantly, it discusses confidence intervals for these mining units, as compared to the relative precision envisioned by a typical classification scheme. The application described in this paper is taken from a medium-sized Cu open and underground mine in northern Chile, and it demonstrates the impact of several variables on the resulting conditional simulation models. It also compares a more ?traditional? resource classification scheme applied, and the wide difference in local confidence intervals for each mining unit.

May 1, 2001

By A. B. Szwilski

"The various elements of longwall mine design are reviewed, particularly as they apply to condition s in the coalfields of the Plains region of Alberta. The following recommendations are made: (1) optimum panel lengths of 1000 to 2000 metres; (2) face lengths of 100 to 150 metres; (3) the use of retreat methods; (4) the restriction of floor undulations to less than 15 degrees. IntroductionThis article considers the elements of longwall mine design and is part of a short study that has been made of the feasibility of longwall mining in the Plains region, Alberta, Canada. The Plains region, with about 20 million tonnes, accounts for more than 80% of the coal resources of Alberta. The coalbearing strata in the Plains region cover an area of about 95,000 square miles. The geological formations dip very gently toward the southwest and, from a mining point of view, may be considered horizontal. The depth of the coal seams varies from several metres to over 650 metres. However, it is not anticipated that underground mining will be extended beyond the depth range of 25 to 250 metre s.The coal seams in the Plains region have been subject to many small mining operations in the past. The majority of these small mines were limited to a depth of about 50 metres, working mainly by room-and-pillar methods, although hand-filled longwall mining was often used.The development of new underground mining operations in the Plains region will have to be on a &apos;start-from-scratch&apos; basis, especially regarding the installation of equipment. Longwall mining is more mechanized than any other method of mining and requires careful attention for the selection of new and expensive equipment. There have been many proven longwall advance and retreat systems in Europe and North America; mining conditions in the Plains region are more similar to those in the United States. Therefore, it will be essential for new mining pro jects in the Plains region to commence with proven system s and equipment; in time, perhaps an experimentation process could be attempted as experience is gained.Generally, the coal face is the key factor in mine productivity, which depends a great deal on equipment reliability, training and experience of the operators. The original design of coal faces must be flexible enough to cater for potential improvements so that running time can be increased."

Jan 1, 1980

By G. E. Agar, J. J. Barrett

"Traditionally, batch bench-scale flotation tests have been used for evaluating flotation reagents by comparing the results of tests done with various additions of the reagent in question. Usually, comparisons are made of the concentrate grade and recovery or some figure of merit involving an empirical combination of both. In some cases, statistical methods have been used to make the comparison and even to identify optimal combinations of reagents.None of the preceding technology utilizes the fact that flotation separations can be described by relatively simple kinetic equations that will serve not only to quantitatively describe the influence of a reagent, but will also aid in designing an optimal separation procedure. Examples of the use of a first-order rate equation for evaluating the impact of a reagent addition and for optimizing the reagent addition are given.IntroductionThe classical method of evaluating flotation reagents is to conduct batch bench-scale tests while varying one factor at a time. Some of the shortcomings of this technique have been pointed out and statistical design and evaluation of experiments has been advocated. Although the statistical approach is superior to the one-at-a-time method, it still is dependent on the results of a batch test conducted for a specific duration.That flotation is primarily a rate process than can be described by a first-order rate equation has been recognized for a long time, but the application of this knowledge to the evaluation of reagents has received little attention. In this work, it is demonstrated how the parameters of the first-order rate equation can be utilized to evaluate the influence of reagents on flotation."

Jan 1, 1983

By João Felipe Costa, Jair Carlos Koppe, André C. Zingano

Abstract - Traditional mine planning based on block models built with interpolation techniques such as kriging does not take into account the uncertainty associated with the estimates. These models are inadequate for short-range mine planning. In contrast, conditionally simulated models reproduce the actual variability (histogram) and spatial continuity (variogram) of the attributes of interest. Conditional simulation can be used to address the problem of measuring the uncertainty associated with an estimate. This paper outlines how the sequential Gaussian conditional simulation algorithm can be used to assess uncertainty of grade estimates and also illustrates how simulated models can be incorporated into mine planning and scheduling. A case study demonstrates the efficiency of the method in assessing risk associated with geological and engineering variables.

Jan 1, 2000

By William Petruk

Mineralogical investigations in connection with gold metallurgy are usually performed to find the reason for poor recoveries by cyanidation or by other leaching techniques. Poor recoveries most commonly are obtained when (I) native gold is encapsulated in an insoluble mineral as "invisible gold"; (2) native gold is coated with a precipitate; (3) gold-bearing products are insoluble in cyanide solutions; (4) carbonaceous material in the ore adsorbs gold; and (5) associated minerals decompose and consume cyanide. Samples of refractory material quite often have low gold tenors. It is difficult to find the gold-bearing minerals in such samples with an optical microscope because the probability of finding trace minerals in samples is small. The probability decreases with decreasing grain size of the gold-bearing mineral and with decreas¬ing gold tenor of the sample. Techniques have been developed to increase the success rate of finding gold grains; some are (1) concentrating heavy minerals; (2) preparing special polished sections; (3) searching with an image analyzer; and (4) dissolving associate silicate and sulphide minerals.

Jan 1, 1989

By Robert B. Parsons

"This month, Tax Notes focuses on two features which can potentially ""dress up"" a new issue of common shares to make the shares more attractive to investors. Attaching warrants to a share issue is a relatively common practice, and recent years have seen an imaginative variety of different kinds of warrants, some of which can be subject to somewhat different tax treatment . A less common financing strategy which certainly deserves some consideration involves the possibility of utilizing ""Share Purchase Tax Credits "" in conjunction with a new share issue.IntroductionPrevious subjects covered in Tax Notes have dealt with flow-through shares and other tax angles which can make equity issues more appealing to potential investor s. Two other techniques which can add zest to a new stock issue involve the utilization of warrants and ""share purchase tax credits"" (or SPTCs). This article takes a brief look at the better known subject of warrants and the lesser known matter of SPTCs.Of course, this paper presents only a relatively general summary of the income tax implications of warrants and SPTCs, and is not intended to be a definitive commentary on all of the detailed and complex tax issues that might be relevant in the circumstances."

Jan 1, 1985

By Xianglin Yang, Hong Zhong, Jingjing Xiao, Guangyi Liu

"The selective adsorption of a flotation collector to a mineral plays a crucial role in enhancing the hydrophobicity of targeted mineral particles for attaching air bubbles in pulp. The recent progress of the structure-reactivity relationship of flotation collectors, the characterization methods for mineral surfaces with adsorbed collectors and their commercial application are reviewed in this paper. Particular emphasis is placed on the density functional theory (DFT) for understanding the reactivity of new collectors, the surface analysis techniques including time-of-flight secondary ion mass spectrometry (ToF-SIMS), in situ scanning electrochemical microscopy (SECM) and atomic force microscope (AFM) to characterize mineral/collector interface, and the flotation technologies for optimizing recovery of valuable minerals. Especially, the recently developing collectors such as Gemini, alkoxyalkylthiourea, dithiourea, amide-hydroxamate and oximido-thiol surfactants, and their specificity to given minerals are evaluated. Based on this crucial review, it is evident that the structural modification approaches for minerophilic or hydrophobic groups, and combined surface analysis approach for further understanding the adsorption mechanism of collectors on mineral surfaces will lay a solid foundation for the future development of flotation collectors. INTRODUCTIONIn mineral processing, flotation is the main process for separation and recovery of valuable minerals from the ores contained them (Fuerstenau et al., 2007). One of the key requirements in flotation process is to increase selectively the surface hydrophobicity of the targeted minerals by collector adsorption so that these mineral particles can preferably attach to air bubbles in a slurry or pulp (Fuerstenau et al., 2007). Flotation collector is a kind of functional surfactant, which is composed of polar and non-polar groups (Somasundaran, & Wang, 2006). Non-polar portion, commonly being linear, branch or ring hydrocarbon group, is termed hydrophobic group. The polar portion, exhibiting strong affinity to mineral surfaces, is known as minerophilic group (Nagaraj, 1988). According to mineral types including saline, oxide and sulfide minerals, flotation collector divides into sulfide and oxide mineral collectors. For efficient recovery of valuable minerals from the refractory complex ores, insights into the adsorption mechanism, hydrophobic model and subsequent flotation approach of flotation collectors have been regarded as an indispensable issue in mineral processing."

Jan 1, 2016

By W. Díaz, R. A. Parra, L. E. Arias, C. A. Toro, M. Marin, E. Balladares, V. Parra, G. Reyes, S. N. Torres, D. Sbarbaro

This work presents visible-near infrared (VIS-NIR) spectroscopy measurements, and signal analytical techniques to characterize minerals and relevant pyrometallurgical process variables for the copper extractive industry. Data signal processing techniques such as baseline correction and numerical analysis are used to estimate the continuous and discontinuous spectral components. Such spectral components are used to estimate the process temperature, and patterns such as the integrated radiation. Also, metal combustion emissivity calculation are depicted. Our findings suggest that VIS-NIR spectroscopy may be a suitable technique to assess the process condition state, appearing as an interesting sensing alternative. INTRODUCTION Although the flash smelting process is one key stage in the copper extractive industry, representing about 40% of copper matte production worldwide (Cantallopts, 2017), few attention is dedicated to develop sensing solutions to assess process variables, such as mineralogical composition and temperature, in the feeding and bleeding stages, compared to the steel industry (Strakowski, et al., 2014). In this process and other industries, e.g. the thermoelectric power generation one, combustion and particularly the generated flame are the production chain’s heart. Since the flame is a highly radiative emitting process where chemical and physical transformations take place, many works had been dedicated to characterize the combustion state by sensing its radiation using optical and photonic technologies (Ballester & García-Armingol, 2010). In this context, this work aims to contribute with visible-near infrared (VIS-NIR) spectroscopy and pyrometry techniques to retrieve relevant information from a laboratory scale flash smelting process. On the other hand, since photonic instrumentation allow us to perform contactless measurements of emitted, absorbed, transmitted or scattered radiation, it appears as a suitable technique for sensing process properties in harsh environments, e.g. high temperature processes. One of these techniques is the Visible- Near Infrared (VIS-NIR) spectroscopy, which provides information about the spectral radiation intensity distribution, in this work, the emitted flame’s radiation. It is well known in combustion research that the spectral emission from a flame is composed by a black body continuous radiation background, molecular emissions, elemental emissions and additive noise features (Arias et al., 2011). To make sense of such information signal processing techniques are needed, here we propose to analyse the continuous and discontinuous spectral components separately.

Jan 1, 2019

By Ross G. Bertinshaw

"The Line Creek Mine of Crows Nest Resources started mining coal in the fall of 1981. There are seven mineable seams with thicknesses ranging from 1.5 to 13 metres and with dips varying from 0 degrees to 60 degrees. This, together with internal partings and the very friable nature of the coal, creates a number of mining problems.The coal is divided into zones depending on the dip of the seam. Each zone requires a different mining technique to ensure optimum recovery and low dilution while still keeping fines to a minimum.Line Creek employs a combination of hydraulic front shovels and backhoes to mine its coal without blasting or use of dozers. This has been very successful in reducing the proportion of fine coal hauled to the plant, thus improving quality control and reducing costs in coal processing.There have been a number of other benefits from the use of excavators instead of more conventional methods. These include better selectivity, good cleanup, reduction in traffic at the face and lower cost.IntroductionThe Line Creek Mine is situated approximately 25 km north of Sparwood in southeastern British Columbia (Fig. I). Preproduction stripping began in J98J with the first coal shipments made in 1982. In 1983 the mine produced 2.1 million tonnes of raw coal.Similar to other East Kootenay coals, the seams at Line Creek are characterized by their friability, producing a large proportion of fine coal during mining. In an attempt to reduce these fines Crows Nest Resources has instituted the use of hydraulic excavators to mine and load the coal.Hydraulic excavators offer other substantial advantages over front-end loaders and dozers, which has been the conventional system in other mines in the area."

Jan 1, 1985

?Bank Lending to the Mining Sector affected by 2 broad factors since Mid 2008: 1. Economic Downturn (?the Real Economy?) for mining companies directly reflected in lower metal prices (current and forecasted). In the case of gold companies, minimal effect. 2. Financial Crisis (?the Credit Crunch?) as it has affected the lending activities of those banks active in the mining sector.

May 1, 2009

By S. Kelebek

Batch flotation tests were carried out using samples from stockpiles that were up to 1.5 months old as well as fresh samples oxidized in the lab for up to six months. Head grades and size distributions of samples were equalized whenever possible. The samples from stockpiles and oxidation experiments produced inferior nickel grade-recovery compared to the fresh sample. The poorer grade-recovery performance was attributable to two factors. First, a significant dilution effect was observed due to complete flotation of pyrrhotite. Secondly, the same stockpiling conditions caused nickel losses that were attributable to non-floatability of some pentlandite. Application of a high pH of 10 compared to the regular pH of 9.2 slowed down pyrrhotite flotation kinetics, but was not able to prevent complete flotation after 8 minutes. The samples oxidized in the lab did not match full characteristics of stockpile samples. They provided somewhat better selectivity for pentlandite. Some correlations were observed on a qualitative basis between surface characteristics such as elemental sulphur formation, activation and flotation behaviour. Oxidation conditions, which induce floatability on pyrrhotite while causing incremental loss in pentlandite floatability appear to be the root cause of difficulties in the processing of oxidized forms of these ores.

Jan 1, 2006

By CIM Mineral Resource

On January 9, 2018, the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Council formed the CIM Mineral Resources and Mineral Reserves Committee (CIM MRMR Committee), which is a combination of the previous Standing Committee on Reserve Definitions and the Best Practices Committee. As part of its mandate, the CIM MRMR Committee updates guidelines for use by Industry, which include the Uranium Practice Guidelines. The 2024 CIM Uranium Leading Practice Guidelines were adopted by CIM Council on November 22, 2024, and supersedes the 2003 version. The main principles and guidelines relating to preparation of Mineral Resource and Mineral Reserve (MRMR) estimates are provided in the CIM Estimation of Mineral Resources and Mineral Reserves Best Practices Guidelines (MRMR BP Guidelines, as updated from time to time). The MRMR BP Guidelines provide information pertaining to metalliferous and other deposits and many sections are readily applicable to the preparation of MRMR estimates for uranium deposits. However, additional guidance is appropriate for uranium deposits due to the radioactive nature of uranium, and its amenability, in some cases, to in situ recovery (ISR) mining methods.

Nov 1, 2024

By N. Vayenas, G. Yuriy

"The combination of a predictive reliability assessment model and discrete-event simulation can be an effective methodology to study the impact of equipment failures on the capacity of production systems in mines. In our case, a predictive reliability assessment model using genetic algorithms is combined with a discrete-event simulation model to analyze mine equipment systems.Discrete-event simulation involves modelling of real-life systems based on variables and events that occur or change at distinct points in time. The Simul8 simulation software, by Visual Thinking, is used in this research. It is a two-dimensional (2D), discrete-event simulation/ animation software tool for creating realistic depictions of manufacturing and materials handling systems.The simulation model developed for the purpose of this research represents a typical two-level, sub-level stoping section of an underground mine in the Sudbury region in Ontario, Canada. This 2D model was created to assess the impact of equipment failures to a mine’s production throughput. In more detail, using mean time between failures (MTBF) data of scooptrams derived from a reliability assessment model based on genetic algorithms, LHD failures are incorporated into the simulation model. These failures cause production interruptions to the development cycle and consequently loss of hauling capacity.Another purpose of this research work is to demonstrate how low-cost simulation tools such as Simul8 can be successfully applied to model underground hard rock mining operations. The research discussed in this paper is carried out by the Laurentian University Mining Automation Laboratory (LUMAL)."

Jan 1, 2005

By N. Romani, R. Provost

"Commissioning of a circulating dry scrubber plant was recently completed at an existing facility, in order to treat the sulphur dioxide off-gas emitted from rotary kilns. Proper planning of the different commissioning stages and staffing an integrated team are the most important factors required for a successful plant start-up. A strong operational readiness plan must be in place as early as the start of construction in order to ensure a smooth transition from commissioning to operations. Plant performance can meet or exceed performance criteria within the required timeframe if the proper group dynamic and good communication is established between construction, commissioning and operations teams.INTRODUCTIONCommissioning of a circulating dry scrubber (CDS) plant was recently completed at an existing facility in Quebec, Canada. The CDS plant treats the sulphur dioxide off-gas emitted from rotary kilns in order to meet increasingly stringent environmental requirements. This installation enables the existing facility to reduce their sulphur emissions by over 90%.The CDS ProcessA general overview of the CDS process is presented in Figure 1 below. The combined, de-dusted off-gas from multiple kilns is sent to the CDS, which acts as an entrained fluid bed, where the gas is contacted with a water mist, re-circulated solids and hydrated lime. The SO2 from the gas stream and the available calcium hydroxide (Ca(OH)2) from the hydrated lime dissolve in the water and react to ultimately form calcium sulphites and gypsum. The solid residue (referred to as CDS residue), is the primary byproductof the process.Fresh hydrated lime and CDS residue is captured by the dust collection system and is re-circulated to the CDS via a fluidised transport system. Clean off-gas passes through the dust-collection system and is then sent to the atmosphere by a single exhaust fan.The CDS residue purged from the system is combined with the dust collected from the kiln offgas system and this mixture is wetted in the already exiting agglomeration system, to minimize dust generation during handling, and then sent to disposal."

Jan 1, 2016

By S. J. Cook

Copper, a world commodity, and the first metal used by man, played a great part in the beginnings of modern civilization, which rests so dependently on the utilization of metals. Then, long after the close of the so-called &apos;bronze age,&apos; when iron and steel had attained great prominence as the world&apos;s most important metals, the practical application of electricity to industry and commerce, for the improvement of every phase of man&apos;s multitudinous activities, gave a new impetus to the production of copper. Improved metallurgical practice made it possible to work low-grade properties at a profit. Research disclosed many new uses for copper. The metal, now produced from the mines of the world in the proportion of about one pound to every 50 tons of pig iron, has attained an importance which rivals that of iron and steel in the commerce and daily life of every nation. New fields of copper-bearing ore have been discovered in Canada in recent years. Established mines in the United States and Chile are producing on a great scale. Africa looms up as one of the great question marks in the future of copper. Whereas, a few years ago, the end of the world?s resources was predicted as being in sight, the evidence now available seems to show that the copper production of the world is likely not only to continue, but to increase for a long time yet to come. Canada&apos;s future in copper is a great subject; in the present paper only a few of the most outstanding factors affecting Canada&apos;s destiny in this large field may be noted, but if consideration of the points raised herein serves to focus attention on the magnificent possibilities of Canada as a producer of copper, the preparation of the paper will be more than justified.

Jan 1, 1928

By C. Moreland

Fluidized low-temperature carbonization of coal, a recent development, offers a possibility of reducing fuel costs of coal-burning electric ?generating plants. The Research Council of Alberta have built a pilot plant and are conducting a programme to -develop a carbomzation plant for Alberta sub-bituminous coals which will produce char suitable for use as a .boiler fuel, and tar of a potentially high value as a ?chemical raw material. The economies of the process as a whole, and the value of the tar, have yet to be assessed.

Jan 1, 1958

By R. B. Roberts, A. L. Mular

A simple way to determine the IEP of oxide minerals is described. The method is shown to apply for fine powders of Fe203 and ZnO. The IEP lies at pH 6.95 for Fe203 and at pH 9.08 for ZnO.

Jan 1, 1966

By Matthew Scott

Introduction The refining of precipitate is the final stage of all the processes involved in gold mining and cyanide milling, by which the precious metal is at last obtained in a concentrated form, which can be accurately valued and marketed. Possibly one ought to say, conveniently shipped, for accuracy in valuation depends in many instances on a toughening treatment given the bars as received at the Mint so as to obtain a homogeneous metal that lends itself to representative sampling; which, of course, entails a surcharge on the regular Mint charges for the extra work necessarily undertaken. There are several methods of refining zinc-gold precipitate, each with its advocates; the method employed depending not always on the quality of the bullion produced but on the local exigencies of the case in point. These methods are more or less detailed in various textbooks and it is not the purpose of this paper to discuss them, but to confine ourselves to the specific case as stated in the title of the paper. At the outset, it behooves the writer to express his thanks to Mr. Brigham, the General Manager of the Hollinger Mines, for the kindly consideration and encouragement given in developing this process. This will be better understood when one considers the immense values involved, tending towards conservatism in practice, and making one chary of radical innovations. This process has been in satisfactory operation now for about two and-a half years, during which time over twenty-five million dollars value in fine gold has been produced, so that it may be reasonably held that the process is successful.

Jan 1, 1931