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By S. Kelebek, E. Yalcin

"Diethylenetriamine (DETA) and/or triethylenetetramine (TETA) are reagents that can generally be categorized under ""flotation modifiers"". These polyamines are known to be effective for the deactivation/depression of pyrrhotite that is present in Canadian nickel-copper sulphide ores in large quantities. Recent bench scale testing on some of these complex ores indicated that chalcopyrite flotation can also be adversely affected under certain conditions involving polyamines, which may be taken to be an evidence of their specific affinity towards chalcopyrite. In general, DETA shows no significant depressant action on chalcopyrite while TETA's promotion of hydrophilicity for this mineral has been observed even in the presence of xanthate. This prompted an investigation on thermodynamic equilibria involving these polyamines and copper ions. Results serve a useful purpose to identify conditions for deactivation phenomena. CuDETA2+ and CuTETA2+ chelates as products of sequestration have large predominance areas covering a wide range of redox and pH conditions, where copper xanthate species are not stable, especially in the presence of TETA."

Jan 1, 2009

By C. Guo, R. J. Chalaturnyk, M. MacKinnon, J. D. Scott

The Mildred Lake Settling Basin (MLSB) is the largest disposal site for mature fine tailings (MFT) at the Syncrude Canada Ltd. oil sands plant. Over the past years (since 1996), there has been a marked change in the densification behaviour of MFT in the MLSB. Methane-producing microorganisms, known as methanogens, have become very active, and large amounts of biogas (mainly methane) have been produced. Continued field monitoring of the MLSB has provided convincing evidence of the rapid densification process (rapid water drainage from the tailings) at the area with intense microbial activity. This rapid densification has caused pumping challenges in the transfer of fine tailings from the Mildred Lake Settling Basin for the creation of composite tailings. It may also have potential positive effects in accelerating the reclamation of the oil sands fine tailings. A field and laboratory research program was carried out to study the mechanism leading to the rapid densification phenomenon. A review and discussion of the research program is given and some results from the field investigations and small-scale column tests are presented in this paper.

Jan 1, 2007

By Kr. N. Karparov

Measurements made with high precision GPS landmarks and geotechnical radar Reutech MSR- 300 associated with the observed movements in the north face of Assarel Mine, where on a horizontal distance of 50 m, 2 groups of landmarks indicated different deformation behavior. Measurements are made in order to confirm the applicability of the radar system in regions of complex geotechnical conditions. The standard deviation of each landmark is used as an accuracy standard between the separate measurements of the deformation vectors made by the high-precision GPS system for each landmark. A very good correlation between the displacement vectors can be seen based on the measurements made with the high-precision GPS system and the measurements made by the radar system MSR-300. Geological, engineering geological and hydro-geological conditions of the area of concern are discussed in this paper. The measured deformations and the FLAC/SLOPE analysis show similar results. In the paper is discussed their local character and their sensitivity to other geotechnical and hydro geological conditions.

Aug 1, 2013

By B P. Scott

Podsol soil horizons developed on Pleistocene glacial sediments overlying the Coronation Mine orebody were analyzed for copper and zinc spectro-photometrically, using biquinoline-isoamyl alcohol and dithizone carbon tetrachloride reagents. Copper and zinc are concentrated in the A. and C horizons, whereas the A1, A2 and B horizons are leached. Of economic significance is the fact that the C horizon contains a copper anomaly, in excess of 100 times back-ground, directly over the orebody. Due to the erratic distribution of high copper concentrations in the Ao horizon with respect to the orebody, that horizon is not considered as a reliable prospecting datum. U NDER certain conditions, metallic ore deposits are accompanied by primary halos of trace elements in unweathered rock surrounding the orebodies or by secondary halos in weathered rock, alluvium, soil, or vegetation above or near the mineralized zones. Where such halos occur, chemical analysis, as applied to the detection of trace elements, is a valuable prospecting aid, permitting the detection of mineralization of possible economic value.

Jan 1, 1965

By J. B. McKenzie

Since connnencing underground prcxiuction in 1979, the Ruttan Mine has been prone to secon:iacy sulphide dust explosions. Al though infrequent during the early years of prcxiuction, these occurrences did result in major damage and lost time injuries. 'As the mine exparrled and developed to further depths, sulphide dust explosions occurred on a more frequent basis. Incomplete ventilation se:rvices, required to exhaust the affected areas, caused frequent delays resulting in lower prcxiuction rates due to the time required to ventilate the affected areas of the mine. CUrrent procedures to minimize the effects of secon:iacy dust explosions evolved from practical suggestions arrl examining methcx:ls other mines have developed to cope with the problem. Procedures and regulations to protect errployees from exposure to hazards of sulphur dioxide are time consuming, expensive and counter prcxiuctive in their present fonn. This paper describes the history of secon:iacy sulphide dust explosions at the Ruttan Mine and the methcx:ls and proced.ures currently in place to minimize and contain the effects of dust explosions.

May 11, 1988

By R. W. Thompkins

MINE operators are concerned with temperature conditions in their mines, particularly the effects of high temperatures on the l1ealth and efficiency of tl1eir employees. This paper is written to focus attention on the variables of heat transfer between rock and air. It illustrates the difficulties of predicting the manner, and the extent, of heat transfer from theoretical concepts, prior to actual operation of a mine airway. There are ~1any sources of heat in mines. The most important is that of the rock surrounding the airway. This heat, in turn, is a product of the age of the rock, faulting, proximity to recent igneous activity, oxidation of sulphides, hot ground waters, etc. The sources of heat may be constant for any one mine, but they are far from constant when dealing with various mining districts or e1•en with a number of mines in the same district. A second source of heat is that produced by machinery in operation. Practically all the waste

Jan 1, 1962

By T Salman

The construction and use of the B.E.T. (gas adsorption) apparatus is described. Examples are given for the determination of large and small surface areas using nitrogen and krypton. Introduction A NY study of the milling of ores from crushing to grinding, classification, and concentration and finally dewatering of the products involves solid particles which are either in contact with a gas or a liquid phase. The surface area of the solid and its characteristics constitute important parameters in all mineral dressing operations. The success of any particular operation is dependent on the interaction of the surface of the solid particles with the gas or the liquid phase. Particle size and specific surface (surface area per unit weight) continue to be important parameters in the flotation research associated with the adsorption of collector molecules or ions on mineral particles, as in the early years of mineral dressing research (1). In order to understand the mechanism of the flotation process, it is essential that the surface properties of the adsorbent be known.

Jan 1, 1965

By K. Morikawa, K. Asano, J. Yoshitomi

The quality requirements for ladle shrouds have become stricter year by year to the pursuit of higher productivity and improved quality in the continuous casting of steel. The ladle shrouds must be sufficiently durable under severe conditions, such as operation without preheating and during several sequential castings. The consideration is that ceramic fibres, which have been applied in shrouds for thermal insulation during casting, could pose a risk to the worker's health. We realized materials for the ladle shrouds which show high strength and low elasticity. At the same time pursuing effective insulation, a coating which contains no fibres (Foaming Coat) has been developed, replacing the conventional one containing fibres. These materials are durable under conditions of repetitive use and consequently satisfy the customer's demands. The ladle shrouds which were improved in this way have achieved an excellent durable life in hot service of three times that of conventional ones. This paper reports the recent technological developments in ladle shrouds as well as their performance under hot operating conditions.

Jan 1, 2004

By Douglas E. Wolfe, Jogender Singh, Robert Miller, Dong-Ming Zhu, Jeff Eldridge

This paper discusses microstructural changes produced by two novel approaches using electron beam physical vapor deposition (EB-PVD) in which periodic strain fields/microporosity was incorporated within the large columnar grains of Zr02- 8wt.%Y2O3 (8YSZ). The traditional columnar microstructure of partially stabilized zirconia has been slightly modified to produce a lower thermal conductive thermal barrier coating (TBC) by periodically interrupting the condensing vapor resulting in microstructural modifications with diffuse or sharp interfaces and morphological changes on the sub-micron scale without changing the composition of the TBC. These microstructural modifications resulted in a 20-30% reduction in the thermal conductivity, 28-56% increase in hemispherical reflectance, improved oxidation cyclic life (over 100%), and better strain tolerance as compared to standard ZrO2-8wt.%Y2O3 deposited on platinum-nickel-aluminide and CoNiCrA1Y bond-coated MAR-M-247 test samples. The TBC with tailored microstructures were examined by various techniques including scanning electron microscopy (SEM), x-ray diffraction (XRD), steady-state laser heat flux technique, and hemispherical reflectance.

Jan 1, 2004

By T. Cutard, E. Yeugo Fogaing, C. Gault, H. Marzagui, N. Prompt, M. Huger, C. Deteuf

This paper deals with studies made in the field of the French research network PROMETHEREF. Several refractory castables are considered in this program. In the present paper, one of these materials is considered, it is a low cement castable based on andalusite aggregates. A particular attention is paid to microstructural changes during the first heating and on their effects on the high temperature mechanical behavior. Microstructural evolutions have been characterized by the way of dilatometry, scanning electron microcopy and X-ray diffraction. In-situ observations by environmental scanning electron microscopy gave complementary results on these high temperature microstructural changes. They deal with microcrack formation, phase changes, crystallization, liquid phase formation and sintering. By propagation of ultrasonic waves, high temperature continuous measurements of the Young's modulus have been made. Results confirm the existence of microstructural changes and allow to quantify the Young's modulus variations all along specific thermal cycles. High temperature four point bending tests and room temperature tensile tests were made in the same temperature range. Behavior evolutions could be found and interpreted with the help of previously mentioned results.

Jan 1, 2004

By G. M. Ross, I. M. Ross, J. A. Scott

"The otherwise waste heat in many water streams in the mining industry can be used to provide space heating of adjacent infrastructure including laboratories, workshops, and offices. This can be achieved by using heat pump systems, which can work as a replacement or in conjunction with existing space heating. In the example investigated—process cooling streams at an ore smelter—the analysis provided illustrates that annual heating costs can be 19% lower and a simultaneous 62% reduction in CO2 emissions can be achieved.RÉSUMÉ Dans l’industrie minière, la chaleur qui serait normalement perdue des circuits d’eau pourrait servir à chauffer des structures adjacentes incluant les laboratoires, les ateliers et les bureaux. Cela pourrait se faire en utilisant des systèmes de thermopompes, qui pourraient remplacer ou s’ajouter au chauffage existant. Dans l’exemple étudié, des circuits de refroidissement de procédé à une fonderie, l’analyse fournie illustre qu’il est possible de réduire les coûts annuels de chauffage de 19 % et d’obtenir une réduction simultanée de 62 % des émissions de CO2."

Jan 1, 2016

By K. D. A. Whaley

The Captain North Extension deposit consists of five sulfide lenses hosted in cherty and chloritic metasediment that is bounded by quartz-eye rhyolite and laminated rhyolite. Lens 2 consists of sphalerite and galena with silver-rich tetrahedrite in chert. Lens 3 contains massive pyrite, with chalcopyrite and minor gold, gradational to minor pyrite in a chloritic metasediment. The other lenses are unexplored. The sulfides occur as beds, fracture infills, and disseminated grains. Reserves are estimated at 207 555 tonnes grading 7.380/0 Zn, 2.76% Pb, and 91.81 g/t Ag. The deposit is isoclinally folded, dips steeply west, plunges 50 degrees south, and is faulted out to the north, where drag folding has reversed the plunge. Minor cross-faults contain talc and sericite. High sphalerite but low pyrite abundances result in poor responses to standard electromagnetic techniques. Lens 3, which contains more pyrite than Lens 2, responds better to induced polarization and allows detection. Geochemical anomalies are found in a nearby swamp and stream, but an impervious till cover inhibits the development of soil anomalies.

Jan 1, 1992

By P. R. A. Andrews

"The sillimanite group minerals, kyanite, sillimanite and andalusite are identified as alumino-silicate minerals with the common chemical composition AIP3.Si02' so that each possesses similar physical properties. Kyanite is the most abundant mineral and mainly occurs in Quebec, Ontario and British Columbia; sillimanite occurs in Ontario and Manitoba; and andalusite in Nova Scotia. The main use for the sillimanite-group minerals is in refractory applications for the production of refractory bricks and shapes. In refractory applications, the main performance criterion is the relative percentage of mullite formed within the material during firing. This phase gives a greater degree of resistance to creep deformation and slag attack, and improves the ability of the refractory to withstand high temperatures under load. The beneficiation of refractory silicate minerals has been the subject of many investigations at CANMET, and the former Mines Branch. Eighteen kyanite, two sillimanite, and three andalusite evaluation studies were conducted between 1933 and 1987. A review of some of the more important studies is presented, which includes information concerning mineralogy, beneficiation methods and flotation data."

Jan 1, 1995

By J .. R. Dalton

"Blasting in high sulphide content ores presents at least two major safety considerations: (1) compatibility of the explosives with the ore while resident in the borehole; and (2) introduction of a flame and shock producing explosive into this environment, while minimizing the risk of reactive ignition in the chemical reaction products/sulphide dust cloud resulting from the detonation. This paper will discuss only the second consideration, i.e. post detonation reactivity.The ETI (Explosives Technologies International) Technical organization, in consultation with the U.S. Bureau of Mines, reasoned that the most relevant considerations in the development of an explosive for this application are:• minimization of reactive gaseous detonation reaction products;• flame duration reduction;• flame temperature reduction;• increased explosive sensitivity;• reduced probability of ""low order"" detonation; and• maintenance of energy level as high as possible.Obviously, not all of these are totally independent properties, i.e. increased sensitivity will reduce the probability oj low order detonation as will higher energy levels. However, these considerations were examined separately as if they were independent."

Jan 1, 1994

By T. Saksala

In this paper, the embedded discontinuity approach is applied to finite element modeling of rock fracture. A rate-dependent constitutive model based on the embedded displacement discontinuity theory is developed to describe the mode I, mode II and mixed mode fracture of rock in tension and compression. The bulk material is described as linear elastic until reaching the elastic limit. Beyond this limit, a ratedependent exponential softening law governs the evolution of the embedded displacement jump. The present approach incorporates the rock heterogeneity by random description of the mineral texture of rock. Moreover, the inherent initial microcrack populations of natural rocks are accounted for as randomly oriented embedded discontinuities. Numerical examples demonstrate the model behavior in uniaxial compression and tension. The effect of loading rate and confining pressure is tested as well in 2D numerical simulations. These simulations show that the model captures the main features of rock in confined compression and uniaxial tension. The developed method has the computational efficiency of continuum plasticity models. However, it has an important advantage of accounting for the orientation of introduced microcracks.

Jan 1, 2015

By Å. Partapuoli, M. Henriksson, P. Wikström, J. Worth, G. Adolfsson

The control of AG mills fed by ores with harder and softer components can be challenging due to the sensitivity of the mill to the ratio of hard to soft components. The mills at LKAB’s iron ore operations are generally well controlled, but there are periods when the throughput falls off dramatically, due to a loss of mill filling. As the ore is upgraded in the sorting plant through magnetic separation prior to milling, this presents an opportunity to manipulate the feed blend in advance. In order to assess this opportunity, a fullscale mill charge was dumped and assayed by size to quantify the build-up of competent waste in the mills. This was supplemented by pilot and locked-cycle laboratory tests at a wide range of feed blends in order to facilitate the development of an appropriate multi-component AG mill model. This paper reports the experimental campaign requirements and methodologies, as well as the major outcomes from analysis and modelling exercises using the industrial, pilot and laboratory multi-component data.

Jan 1, 2012

By G. M. Ritcey, V. M. McNamara

"In the processing of gold ores by the cyanidation route, effluents which are discharged to the tailings areas can contain up to several hundred parts per million of cyanide in complex combination with similar quantities of heavy metals. Complicating this obvious problem of waste control are concentrations of thiosalts and thiocyanates which are roughly equivalent to the amounts of cyanide species. Although most gold mills are located in thinly populated areas, such contaminants can represent a potential environmental problem due to the various limitations exhibited by on-property ponding.The former Extraction Metallurgy Division of CANMET recognized the problem and, in early 1974, invited representatives of the gold mills to Ottawa to discuss the situation. At that meeting members of the Division presented a ""state of the art"" literature survey of cyanide abatement technology for waste solutions, together with preliminary cost estimate data(1). Shortly thereafter, Environment Canada, together with Environment Ontario, decided upon a guideline of 0.1 ppm (0.1 mg/l) total cyanide content as tolerable for an effluent stream which is discharged, in any manner, to the watershed."

Jan 1, 1978

By Bennett McLaughlin, Gille Brousseau, John F. Cook

"La Mine Bousquet commenced operations in October 1979. Mining has been by underground methods from two main zones which dip steeply to the south , Sub-level stoping methods with following fill are used.The orebody and immediate country rocks are sericitic and highly schistose. The intensity of schistosity varies significantly and poor ground conditions prevail, especially within the orebody,Initially few mining problems were encountered but in May 1981, significant damage occurred. A system of stabilizing pillars was introduced with improved support systems. Predevelopment in ore and pre-drilling of blastholes were reduced with extra footwall development.Damage has continued to occur on a regular basis particularly during the spring thaw. Generally, the adverse conditions have been successfully overcome.IntroductionMost of the mining problems that have been experienced at Bousquet have been caused by poor ground conditions . This pa per describes these conditions, considers the cause and describes the ways in which the conditions have been dealt with . Despite the problems, Bousquet is a successful operation which in 1983 produced 95,000 ozs of gold from 514,000 tons of ore."

Jan 1, 1985

By D. A. Mackie, J. E. Rider

"Good belt conveyor design is the most often neglected detail in the engineering of a plant. This results in downtime from spills or jams and premature failure of equipment components. Careful layout and component selection will result in better operation, a cleaner plant and therefore lower maintenance costs.IntroductionDespite the availability of many excellent sources of data on conveyor design, such as the Conveyor Equipment Manufacturers' Association (CEMA) Manual, ""Belt Convyors for Bulk Materials"" , there continues to be repetitive errors made in design. Why? Certainly, there is no substitute for experience, but largely, classical errors in belt conveyor design is rather elementary and so the temptation to have the work done by relatively inexperienced designers is great. What that does is develop "" experienced"" designers who become incompetent through no fault of their own. It is hoped that this paper will supplement available design data, help those who are "" put into"" a design situation to better cope with their predicament, and ease the lives of plant maintenance personnel."

Jan 1, 1990

By W. F. Giuvlore, E. Mcroberts, T. S. Golosinski

"The rising demand for Canadian coal and depletion of shallow deposits, most suitable for surface mining, result in rapidly increasing volume of waste materials which have to be moved by the coal mining industry. While at present this challenge is being successfully met using conventional mining methods, in the future, innovative methods must be considered if Canadian coal is to remain competitive.The need for more efficient mining methods is also faced by the oil sands industry to assure competitiveness of the synthetic oil price.A look at the world mining practice indicates that large volumes of material can be economically mined and moved by the continuous mining systems comprising bucket-wheel excavators, belt conveyors and stackers. To assess the state of art and applicability of this mining method to Canadian conditions, the field trip was organized by the Department of Mining Engineering o f the University of Alberta, to several typical mining operations in Europe. It is in Europe where the continuous mining methods were developed and are almost exclusively used in large-scale surface mining."

Jan 1, 1984