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By E. V. Manlapig, M. A. Hampton, M. E. Holuszko

Methanol treatment of ZnS particles has been found to remove slimes and facilitate flotation. The removal of slimes renders the ZnS surface more hydrophobic, resulting in an increase in the hydrophobic attractive force between the particle and bubble. Hallimond tube flotation, induction time measurement and particle-bubble force analysis with the atomic force microscope (AFM) was undertaken to link the beneficial effect of methanol treatment of ZnS particles to their increased floatability.

Jan 1, 2009

By I. Farr, H. Wittens

"In 1989 and 1990 abnormally high levels of arsenic in ore from the Thompson Open Pit Mine threatened Manitoba Division's electro-nickel production. The paper will discuss our development of a flotation process to separate pentlandite and gersdorffite (the prime nickel and arsenic bearing minerals).The presentation will focus on the development of the process from conception, through lab and plant test work, to plant optimization and full scale production. The paper will conclude with the benefits and cost of the completed project.INTRODUCTIONRejection of arsenic from nickel sulphide ores was not a primary concern in the Manitoba Division until 1989. At that time increased production in the Thompson Open Pit mine, which contains high arsenic ore zones, resulted in excess amounts of arsenic in the Thompson Refinery affecting electro-nickel quality. This problem was resolved through extensive efforts by Mill personnel. The purpose of this paper is to familiarize the reader with- the Thompson Mill.- the mineralogy of the Thompson orebody.- the evolution of Ni/As separation in the Mill.- the metallurgical impacts of the separation on the Mill.- the importance of the separation to the Manitoba Division."

Jan 1, 1991

By M. D. Everell

Le Centre de Recherches minérales (CRM), qui est un organisme de recherche appliquée du ministère de l'Energie et des Ressources du Québec, a été créé en 1969, dans le but de procurer un support scientifique et technique à l'industrie dans le domaine des mines et de la métallurgie. Pour atteindre ses objectifs, le CRM met à la disposition de l'industrie un personnel spécialisé et compétent dont une quarantaine d'ingénieurs et de scientifiques. Etant donné la nature même de l'industrie minérale, ce personnel est très versé dans l'étude des problèmes diversifiés des domaines de la technologie minière, du traitement des minerais, de la métallurgie extractive et de l'analyse minérale. Ce Centre de recherches met également à la disposition de l'industrie une usine-pilote permettant de reproduire les résultats du laboratoire au moyen d'un appareillage de type industriel, d'obtenir des échantillons en quantité suffisante pour une exploration du marché et de familiariser du personnel avec les opérations normales de l'industrie. Certaines de ses contributions récentes au développement de l'industrie minérale du Québec seront présentées.

Jan 1, 1985

By M. W. Wadsley

"Physical and chemical property models are widely used in process engineering. There exist, in the published literature, completely empirical models of ''thermodynamic properties"", that is, property models that are not consistent with the laws of thermodynamics. There also exist property models that purport to be thermodynamically consistent but are flawed in their implementation. There are also published property models that are consistent with the laws of thermodynamics but that do not reproduce property values with an acceptable accuracy. A practicing engineer might be asked to assess very different property models for which there are a variety of claims. This paper discusses features of thermodynamic and empirical property models that may assist in their practical evaluation and implementation."

Jan 1, 2005

By A. J. Faulds, K. C. Westaway, Z. Waszczylo

"PAH compounds have been found in the exhaust from all types of engines burning hydrocarbon fuels . They have also been found in the air over cities and in water. The authors report on a study to assess the concentrations of twelve different PAH compounds in several different environments in dieselized underground mines. In addition, the differences in the PAH levels and distributions in different mines will be demonstrated. Finally, the influence of blasting and the type of diesel engine used as well as the effect of catalytic converters in the exhaust system on the PAH concentration in the mine will be discussed.IntroductionMining methods have been altered significantly in the last 25 years; i.e ., the tools and machinery used underground have changed from electrically operated trains and other equipment to diesel-powered equipment. This has been done for several reasons: 1) economics, 2) convenience and 3) safety. Today, most mines are heavily committed to using diesel equipment.Although the introduction of diesel equipment has revolutionized mining methods and has been a tremendous boon to the mining industry, it has also created new problems. These problems arise because the exhaust from diesel engines contains several pollutants which can be hazardous to the health of the miners. These pollutants are CO2, CO, NO., SO2, oxygenated hydrocarbons produced during the buring process and unburned hydrocarbons. There are two classes of hydrocarbons, of which polynuclear aromatic hydrocarbons (PAHs or PNAs) are a part."

Jan 1, 1981

By P. Abachi

Cemented carbides or hard metals that generally consist of hard tungsten carbide and a tough metal binder such as cobalt are important in many segments of the world economy, ranging from automobile related components to machining, cutting, and drilling tools. For metal cutting operations such as turning and milling, replaceable cemented carbide inserts are frequently used. The exposure of inserts to very severe conditions (e.g. temperatures as high as 1000°C) in combination with very high loads, limits their lifetime. When the tools and components are scrapped, they are collected with a view to recovering the tungsten carbide and cobalt due to both their environmental aspects and their strategic importance. In this work, a selective electrolysis process was used for recovery of WC powder particles from cemented carbide scraps. The WC-10Co and WC-10Co-VC up to 3 wt.% VC was produced using powder metallurgy route. The mean particle size of WC, Co and VC were selected as 2.5, l.5 and 2.2 µm respectively. Referring to electrochemical curves of WC-10Co cemented carbides in hydrochloric acid solutions with different concentrations, the recovery rate was enhanced in IN acid. Therefore, this solution was selected for recycling of all samples. The surfaces of as-produced and corroded specimens were investigated using a scanning electron microscopy (SEM). Detection of corrosion products was provided by energy dispersive spectrometry (EDS). According to results, the selective electrolysis process could be useful in the recycling of scrap carbide materials, although more studies should be undertaken on economical aspects of the process and the quality of samples produced using recovered powders.

Jan 1, 2005

In the present work, the effect of pH, non-ionic polyacrylamide flocculant and anionic polyphosphate on rheology and settling behaviour of colloidal TiO2 suspensions (15 ? 50 wt% solid) is investigated. Maximum particle aggregation, reflecting in the highest suspension settling rate and maximum shear yield stress was achieved at pH 7.2, the isoelectric point (iep), consistent with DLVO expectation. However, the maximum aggregation condition at the iep also resulted in the poorest suspension consolidation behaviour. Significantly enhanced consolidation was achieved for a more dispersed suspension at pH values away from the iep but at reduced settling rate. Thus, when pH alone is used to control conditions which facilitate strong interparticle attraction, a high settling behaviour which is not conducive to compact consolidation results. Improved suspension consolidation may be achieved at the iep via anionic polyphosphate addition which leads to attenuation of the strongly attractive van der Waals forces and emergence of "soft" repulsion due to weak inter-particle electro-steric forces. The weak repulsion act to lubricate particles involved in the hydrodynamic interactions which controls the compressibility of the sediment bed, allowing a compact consolidation of solids to be obtained. Alternatively, non-ionic polyacrylamide homo-polymer (Magnafloc 333) was fairly effective in flocculating titanium dioxide suspensions leading to high settling rate and acceptable pulp consolidation at the iep.

Jan 1, 2006

By Josée Dartois

En 1988, à l?instar de plusieurs états du monde industrialisé, le Québec décidait d?accélérer la cadence de l?assainissement des rejets industriels et lançait un programme intégré de réduction de la pollution industrielle visant, à la fois, les rejets dans le milieu aquatique, les émissions atmosphériques et les matières résiduelles. Ce programme fut intitulé le Programme de réduction des rejets industriels.

Nov 1, 2002

By L. B. Tsymbulov, L. Sh. Tsemekhman, A. N. Golov

Gipronickel Institute, JS is developing a process of continuous converting of Nicontaining copper matte and concentrates resulting in the production of blister copper and fluid NiO-containing slag in a two-zone Vaniukov furnace. The process under development is an alternative for the existing technology of blister copper production in converters, the latter being characterized with insufficient sulphur utilization, low direct copper recovery and the production of inconvenient for further processing solid slag on the basis of NiO and NiFe20 4- The results of pilot testing on processing of copper concentrate obtained from high-grade matte (HGM) separation in the two-zone Vaniukov furnace with the hearth area of 11.4 m2 are presented.

Jan 1, 2007

By John G. McCamis

The Maritimes Carboniferous Basin is the largest intermontane basin in the Appalachian Mountain System, occupying a total area of 57,200 square miles and containing up to 30,000 feet of late Devonian through Permian .sediments. Deposition began with continental elastics in late Devonian and early Mississippian. Marine deposition is represented by a limestone-evaporite sequence of late Mississippian age. Pennsylvanian and Permian continental rocks deposited largely in flood-plain and swamp environments complete the succession. Marine seismic data disclose several varieties of structure, both halokinetic and tectonic in origin. Recent exploratory drilling in the offshore part of the Basin encountered good reservoir rocks in the Riversdale sandstones, which also provided encouraging shows. The most likely source rocks of hydro~ arbons in the Maritimes Basin are shales in the Horton and Riversdale groups. Potential recoverable reserves of the Maritimes Basin are estimated to be 400 million barrels of oil or 7.8 trillion cubic feet of gas, based on the volume-of-sediment method of calculation.

Jan 1, 1973

By S-E. Vandat

The goal of this work was to select an appropriate electrode for dummy load of diesel engine in fully salt-water in the DESA factory. The electrochemical corrosion rate of general structural steel, commercial pure aluminum and cathode copper calculated as weighting, volumetric and commercial in fully salt-water by city power. After several tests and then applying the fuzzy logic method, it was determined that general structural steel is the best selection for this purpose.

Jan 1, 2005

By W. A. Padgham, J. A. Brophy

About 85 % of the 350 tonnes of gold produced by 25 mines in the onhwe t Territories (NWT) since 1935 has come from the Yellowknife-area mines, Con and Giant , which exploit shear zones in Archean mafic volcanic of the Slave Structural Province. Four percent of the total production has been from Archean iron formation-hosted depo its, mainly from Lupin Mine, which today produces more gold than Con and Giant combined and has been primarily responsible for the increase of WT gold output from 5 to 12 tonne per year since 1981. The remaining gold ha been won from the following deposit typesall but the last being in Archean rock : sedimentary-volcanic contact depo its uch a Discovery and Salmita (10 %); turbidite-hosted quartz-vein depo its uch a Camlaren and Ptarmigan (1%); Proterozoic deposits such as Shear Lake and Fox (1#) . All but I% of WT gold has come from the Archean Slave Structural Pro ince, which is also the premiere exploration area for gold deposit types that have yet to be productive in the NWT. These types include stratabound gold in mafic and in felsic volcanic rocks (eg. , at Indin Lake and Courageous Lake, respectively) as well as gold in plutonic rocks (eg. Anialik Gnei Complex). Deposits similar to those in the Slave have al o been found in the Archean Ennadai Belt of the Churchill Structural Province. In the Cordillera. there is potential for placer gold and for gold associated with Cretaceou intrusions.

Jan 1, 1986

By P. -Q. Wu

A modified electrochemical noise (EN) technique has been applied to monitor corrosion wear of TiN-coated ASP23 steel and TiN-coated AISI 316 stainless steel sliding against corundum in 0.5 M H2SO4. Experimental results show that the EN technique can sensitively detect potential and current variations during a corrosion-wear process. Corrosion-wear mechanisms of TiN coatings depend on their substrate properties. If the substrate is passive, such as AISI 316 stainless steel, the potential and current variations reflect the properties of the coating. Depassivation and repassivation alternately take place on the tribo-activated wear area during the steady-state phase. If the substrate is active, such as ASP23 tool steel, the electrochemical noise is dominated by dissolution of the substrate at the pinholes and the hydrogen evolution all over the exposed surface.

Jan 1, 2005

By V. P. Mehrotra, D. W. Fuerstenau, A. -Z. M. Abouzeid

The use of pulverized coal for electric power generation results in the production of vast amounts of fly ash. One potential use for waste fly ash is the production of pellets for lightweight aggregates. This paper is concerned with the role of the physical and chemical characteristics of two different fly ashes in governing their agglomeration or pelletization behavior and their strength characteristics. In batch balling experiments, fly ash pellet growth was found to be extremely sensitive to the amount of moisture added. One ash (Mohave) exhibits marked pozzolanic activity whereas the other (Jim Bridger) does not. The pozzolanic activity has a very pronounced effect on pellet growth kinetics, moisture requirements, and the effect of various additives on growth kinetics. Slow drying under ambient conditions produces strong pellets from Mohave ash whereas Jim Bridger ash pellets lacking in pozzolanic activity are weak. Rapid drying at high temperatures results in weak pellets because water necessary for hardening is driven out of the pellet. Steam curing enhances pellet strength. Locked-cycle pelletizing experiments exhibit expected oscillation in pellet production rates and attendant fluctuations in pellet green strength.

Jan 1, 2004

By J. Lu, D. G. Ivey, H. Henein

Microalloyed steels are widely used in the oil and gas industry. They are a class of high strength, low carbon steels containing small additions of niobium (Nb), titanium (Ti), molybdenum (Mo) and/or vanadium (V). These steels have good strength, toughness and excellent weldability, which are attributed in part to the presence of nano-sized carbides, nitrides and carbonitrides. In the pursuit of developing higher strength microalloyed steels, it is of great interest to quantify the size, distribution, volume fraction and chemical speciation of these precipitates. However, characterization techniques suitable for quantifying fine precipitates are limited. Possible characterization techniques include SEM, TEM and matrix dissolution. A comparison is presented of the various techniques.

Jan 1, 2005

By P. Tukkaraja, K. Katzenstein

"Block caving is one of the most economical and efficient underground mining methods and has gained popularity around the world especially for extracting low grade and massive ore bodies. However, during the extraction of ore from the draw bells, gases trapped inside the cave could emit into the working areas; hence, ventilation plays a key role in operating block cave mines successfully where gas emission is a concern. To design an effective ventilation system for a block caving mine, given the dynamic nature of the caving process, it is necessary to develop airflow characteristic curves (P-Q) for a given cave. This study uses a 1:100 scale physical model with an exhaust fan system, and a Computational Fluid Dynamics model of a block cave to investigate the airflow behavior through the cave filled with broken rock material. From this study, it was observed that the cave airflow resistance increases with the decrease in cave porosity and the particle size.INTRODUCTIONThe block cave mining method is gaining popularity owing to its low cost and high productivity. This study considered a case where this bulk mining method is used for the extraction of an orebody that contains uranium mineralization. During the extraction of broken ore from the draw bells, radioactive gases trapped in the cave zone could be released into the production drifts and could create unsafe working conditions in the mine. Mine ventilation systems play an important role in regulating the migration of radon in working areas. One of the strategies to control radon migration in a block cave mine is to exert negative pressure on the cave zone by using an exhaust fan above the cave zone. In order to select an appropriate exhaust fan system, it is necessary to study the airflow resistance of the cave zone (Loring & Nelson, 2006).Extraction of broken ore via drawpoints creates a void volume inside the cave called the air gap. Air gaps with larger heights can lead to air blasts in a block cave mine should the cave collapse. Besides that, the air gap can also lead to decrease in ventilation system efficiency due to recirculation of air flow and associated shock losses. Air gap height can also have a profound effect on the variation of cave airflow resistance (Erogul et al., 2015, 2017). The knowledge of cave airflow resistance is also important for predicting the intensity of an air blast. Cave airflow resistance is a function of cave properties such as broken rock size, air gap, and porosity inside the cave zone (Baysal et al., 2017). Initially, a scaled experimental model with a forcing system was developed to investigate the airflow behavior through the cave, however, this model couldn’t provide an observable change in the airflow resistance when the cave properties were changed (cave porosity, and airgap) This was attributed to the difficulties associated with forcing system in terms of achieving lower porosity values with the available material (lightweight shipping boxes) for simulating broken rock inside the cave zones, and controlling air leakage from the model (Ajitha et al., 2018)."

Jan 1, 2019

By Harry Wilton-Clark

Introduction Coal cleaning may be taken as meaning the separation of coal-as-mined into two or more fractions. Coal cleaning includes coal washing, together with any other means used in the ultimate preparation of coal prior to shipment (as coal) . The method of coal cleaning devised for any given mine must be one which is based entirely on the economic results obtainable. The installation of a high-cost and complex washing plant, designed to produce a low-ash dean coal, at the highest possible recovery, may be unsound practice. A crude 'roughing' washer may be the best result of sound engineering and operating consideration, and in some cases coal cleaning should be confined entirely to preparation at the face. Consideration of complete costs, to the point where the coal is actually sold, may show that certain seams are workable or not workable. Of the seams found workable, extraction of the whole or parts of the seam may be decided on. The portion to be extracted may contain rock or bone partings, which must be removed. It may be good practice to mine the extra portion and remove the objectionable materials by surface washing; or it may be that such materials should be removed underground, even at an increased mining cost. For instance, in some of the steeply pitching seams of the Alberta Crow's Nest Pass district, the removal of bone and rock at the face may be almost impossible under the usual 'up the pitch' or 'angle' mining methods, but possible by mining across the pitch so that the material to be rejected can be removed and gobbed. Again, if a complete seam is being extracted, investigation may show marked differences between top coal and bench coal, and if sufficient mine cars are being loaded from a chute at one time, the fact that such a place is working top or bench coal at the time may be reflected by peaks in ash content or size proportions at the ripple. It may be very effective coal preparation to smooth out such peaks.

Jan 1, 1934

By L. Telfer

Summary During Palaeozoic time, there were deposited in the Canadian Rockies four beds of phosphate rock, ranging in age from Mississippian to Jurassic. Two of these beds are of probable economic importance if some means of separating the phosphate from the gangue can be devised. All the more important beds of phosphate rock so far discovered are just behind the front ranges of the Rocky mountains, within fifty miles of the prairie lands of Alberta. Mining conditions are favourable, with an abundance of timber and ample power available. The phosphate beds are all of the sedimentary type, and they all occur, apparently, at the same stratigraphic horizons over a wide area. The conditions necessary for deposition evidently occurred at several different periods in geological time, and were widespread. The most important factor appears to have been the condition of the land surface surrounding the basin of de-position. Both oolitic and nodular phosphate were laid down under nearly similar conditions. Introduction Following the discovery of phosphate rock in Idaho and Montana, search was commenced in Canada to determine whether formations of similar age in the Canadian Rockies carried similar beds of phosphate. The most widespread search has been that undertaken by the mines department of the Consolidated Mining and Smelting Company of Canada. The following paper will discuss some of the results of this exploration.

Jan 1, 1933

By G. K. Rutherford, G. W. Van Loon

"Tailings in the mining and smelting industry are reject products of the refining process which are deemed too deficient in native are to warrant smelting. They are essentially finely ground rock materials which have been moved by alluvial suspension from the site of crushing to a deposit site. It is realized that components of flotation chemicals used in specific gravity separation may become part of the tailings and also that sewage sludge or other materials may be added at some stage to the tailing deposits.It would seem, then, that as tailings have a similar parent material to soils, namely rocks, and that they have also been comminuted to similar size fractions, they would react in similar ways to soils. There is an increasing body of evidence and experience which both supports and negates this supposition. It is the object of this paper to point out similarities and contrasts between these two materials which may influence the vegetation and rehabilitation of tailings.Soil-Formlnq FactorsThere are considered to be six soil-forming factors which impart the particular and unique properties harboured by a soil at any site. It is .relevant to consider each of these in turn, as each provides an historically based parameter with which to judge tailing properties.Parent MaterialsAlthough all mineral soils have originally come from rocks, for most soils the route has been rather circuitous. Soils may be formed directly from underlying rocks, as in some parts of tropical and semitropical regions today; these are sedentary soils. However, most soils of the world have been formed by materials which were transported to their present site by ice, water or wind, or as volcanic ash. Virtually all soils in Canada have been transported by ice or water and deposited on an extraneous rock surface during the last glacial retreat. Ice-deposited materials are extraordinarily heterogeneous in their size components and may range from very bouldery and gravelly to predominantly clay-sized materials. Water deposited sediments are usually homogeneous, but nevertheless these also show considerable level variations. In many parts of Canada, clay-sized materials deposited in ephemeral post-glacial lakes form the parent material for soils."

Jan 1, 1982

By A. A. Goss

We investigate the relationship between corporate financial performance (CFP) and environmental and social performance (CSP) in a sample (n=165) of large, publicly traded U.S. mining and oil and gas firms. Using optimally scaled principal components analysis to generate aggregate measures of CSP strengths and concerns, we find higher concerns are related to higher volatility of unexpected earnings and discount rates. Furthermore, these earnings shocks are more likely to be negative as concerns increase. Decomposing this relationship shows that negative environmental performance dominates proactive environmental management as a driver of unexpected earnings, but proactive community efforts increase the magnitude of earnings shocks. We document some evidence of the strategic use of CSR, with those firms that have greater risk investing more proactively in CSR.

Aug 1, 2013