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By P. P. Rosario

A research project was conducted at the University of British Columbia (UBC) resulting in the development and evaluation of a novel comminution circuit incorporating autogenous grinding and parallel trains of cone crushers and high-pressure grinding rolls (HPGR). A primary driver for the circuit was to treat ore from deposits with clay and variable hardness. This paper summarizes the unique pilot-plant test program that was developed as a basis for experimental simulation and lists the main findings of the research, including the circuit?s potential operational cost savings compared to a conventional SAG circuit.

Jan 1, 2012

By L. Rodd, C. Walker, T. Koehler

"The energy content of slag represents approximately 80% of the total energy inputs to a laterite nickel electric smelting furnace. Conventional slag handling methods produce only low grade heat and the entire thermal content of the slag is wasted. A heat recovery system proven on BOF slag in the mid 1980's can be adapted to a laterite nickel rotary kiln electric furnace (RKEF) plant. Slag is granulated using a high velocity air jet inside a waste heat boiler to produce slag granules. Granules are cooled during flight via radiation to water-cooled boiler walls and by convection to the granulation air. This system has the potential to recover 80% of the total slag energy in the form of hot air and steam.Integration of the recovered slag energy into the RKEF smelter can be achieved by a number of methods, including the use of preheated air at the ore dryers, kiln or existing power plant. Energy from the slag boiler may be used to reheat boiler feed water from the power plant or to produce superheated steam and generate electricity. The heat recovery system can provide up to 25 - 30% of the total electrical requirement of each RKEF line and a reduction in CO2 emissions of 234,000 tonnes per year.The total cost of slag heat recovery, including CAPEX and OPEX, is $2.5/GJ, which is competitive with using coal when CO2 credits are $18 per tonne. With Clean Development Mechanism (CDM) carbon credits currently selling at €13 ($20 USD) per tonne CO2, there is considerable opportunity for slag producers in regions including South America, Korea, Indonesia and Africa. Increasing fuel costs and more wide-spread legislation for GHG emissions will likely create conditions in which slag heat recovery could generate a favourable return on investment."

Jan 1, 2010

By I. Ciabatti

Inorganic salts of hexavalent iron (ferrate (VI)) are versatile reagents for water and industrial effluent treatment because of the strong oxidising effect of the ferrate ion (FeO42-) and the well-known coagulation properties of the resulting ferric ion. Among other applications, ferrate can effectively remove arsenic, cyanide and phenols from industrial effluents. Furthermore, ferrate salts can be prepared from ferrous sulphate, a common byproduct of the steel and titanium industries, and possibly from other iron wastes. Notwithstanding their many potential advantages, the industrial-scale application of ferrate salts, such as potassium ferrate (K2FeO4), for effluent treatment has been hindered by the difficulties inherent in their synthesis and stabilisation. Within a project co-funded by the European Commission, the large-scale synthesis of stabilised potassium ferrate was realised through a new synthesis process, and different applications of the resulting ferrate to effluent and wastewater treatment are under investigation. This paper reports the results of the application of stabilised potassium ferrate for the purification of textile effluents. Laboratory and pilot-scale tests were carried out and the performance of the ferrate was compared to that of chemicals currently used in wastewater treatment. According to these experiments, potassium ferrate is a promising reagent for an effective treatment of textile and other industrial effluents.

Jan 1, 2006

By A. G. Roach

IT IS generally stated that the gold ores of Nova Scotia are free-milling, and for the most part this is true. However, there is a certain proportion of the gold finely disseminated throughout the sulphides, notably arsenopyrite, and this gold is definitely not recoverable as 'free-milling' gold by amalgamation. The proportion of free-milling gold to total gold seems to vary widely in different localities in the Province and is lowest in deposits of the fissure-vein type. The problem of recovery of these relatively recalcitrant values is usually one of economics, in some plac.es a simple gravity concentrate being of such low tenor that its extraction and subsequent disposal will not bear the costs involved. In other cases, such a high percentage of values escapes from the mortars and plates that concentration is definitely indicated. The size of the mining operation is also an important factor. In the large majority of cases, however, some concentrating step is warranted, even if the resulting concentrate is stock-piled until sufficient has accumulated to justify further treatment.

Jan 1, 1940

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 'bronze age,' when iron and steel had attained great prominence as the world's most important metals, the practical application of electricity to industry and commerce, for the improvement of every phase of man'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's future in copper is a great subject; in the present paper only a few of the most outstanding factors affecting Canada'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 Clifford S. Gibson

THE Workmen's Compensation Ace defines Silicosis as "a fibrocic condition of the lungs caused by the inhalation of silica dust sufficient co produce a lessened capacity for work". This fibrocic condition muse exhibit a specific appearance in the X-ray picture of the chest-an appearance which is not characteristic of several lung conditions which can cause lessened capacity for work and which are not due co silicosis. The layman is sufficiently familiar with this subject co know chat, as far as our knowledge goes, quartz is one of the principal objectionable factors in the production of this condition. He should also know that silicosis respects neither geographical nor industrial boundaries. It is as much a factor in some industrial processes (e.g. foundry work, sandblasting) as it is in mines handling ores containing quartz. Its development co a recognizable stage is usually a matter of many years. As yet, its cure is unknown. Its prevention is possible in varying degrees. The layman should also know that the development of fibrosis may be accelerated by breathing in, or living in, any atmosphere containing dust. Few normal adults, particularly those above a certain age, have clear lungs, and fibrosis in varying degrees is noted in the farmer, the steel worker, the clerk, and many others in varied occupations. It is not restricted to miners. Medical and industrial journals, and at times the press, are crammed with data pertaining to this subject, much of which is misinformation. This is particularly true of certain !laces where the preventive and compensation measures for the good o those earning their livelihood in an industry in which silicosis may be contracted are not so far advanced as in our own Province. A great many of these publishings are alarming to the layman. They leave him with the impression that he is taking his life in his hands if he elects to work underground, particularly in a gold mine-that he has at once sold his heritage of health and chat sooner or later he will succumb to the ravages of this ailment. Nothing could be farther from the truth. Actually, under present conditions in Ontario mines, a very small percentage of the men employed ever become impaired by silicosis to the extent chat they must withdraw from the industry. I propose to tell you briefly something of this subject as it affects our mines.

Jan 1, 1937

By G. E. Willey

F OR many years, only one grade of structural steel has been used in volume in Canada. Its characteristics have not been altered appreciably and its long use speaks well for its performance. This standard grade of structural steel may be bought and specified as C.S.A. G40.4 steel or the American equivalent, A.S.T.M. A7. The principal limitations and requirements of this specification are shown in Table I. Within the last five years there has been a growing awareness among the steel producers and steel fabricators that economic forces are at work which make desirable the availability of new and better grades of structural steel. Competition from other materials has increased. The use of concrete bridges and pre-stressed concrete beams is a prime example. New sources of steel from outside the country have become a threat to the Canadian industry and its high cost-price structure. The need for improved properties in the steel, to make possible technologic

Jan 1, 1962

By R. A. McGuire

THE recorded production of the Sheep Creek camp from 1900, when the Yellowstone Mining Company first put its mill into operation, to the present day is in excess of $17,500,000. Of this total, $2,500,000 can be attributed to the early period from 1900 to 1916, at which time increased costs of labour and material due to the Great War forced abandonment of any operations on a large scale for a number of years. Since the camp was revived in 1929, at which time the Reno mine started large-scale operations, and the early 'thirties', when the increased price of gold induced the commencement of operations on other properties in the district, total gross production has been in excess of $15,000,000. In addition to the above totals, intermittent shipments were made by lessees and small operators, principally during the period of inactivity from 1916 to 1929, but no records of this production are available. The Sheep Creek camp would rank fifth in the Province-behind Rossland, Portland Canal, Bridge River, and Hedley-in gross gold production, but, because of relatively inexpensive mining and milling costs, would occupy a more prominent position in regard to total dividends paid. Operating mines at the present time include Reno Gold Mines, Gold Belt Mining Company, Kootenay Belle Gold Mines, and Sheep Creek Gold Mines. Each one of these companies, with the exception of Kootenay Belle, represents a consolidation of several smaller properties, all of which were in existence for a number of years prior to 1929. These four companies, at the present time, own, or hold options on, practically all the important claims in the district with the exception of a very few claims and fractions still held by private owners.

Jan 1, 1942

By Rong. G., T. Q. Lin, W. Du

Based on analysis of the evolutionary history of the valley in Baihetan, the mechanism of asymmetrical evolution, gradual migration-incision evolved from left bank to the right, is revealed in Baihetan river valleys. The process of in-situ stress evolution is carried out by using the Universal Distinct Element Code (UDEC). Consequently, the numerical results which indicate the main regulations of that stress field are as follow: (1) The phenomenon termed "high in-situ stress fold" appears in the bottom of the valley. With the maximum principal stress being 28-34 MPa, the stress increases significantly at a vertical depth of approximately 130 m. (2) The in-situ stress presents zonal distribution along the bank slope. It is apparent that the in-situ stress field consists of stress relaxation zone (SRZ), stress concentration zone (SCZ) and original stress zone (OSZ). The horizontal depth of stress relaxation zone varies from the left bank (roughly 200 m) to the right (about 120 m). Furthermore, the stress evolution of the left bank slope is studied. As a result, it is found that asymmetrical erosion contributes to the difference of the in-situ stress distribution as a critical factor, between the left bank and the right. And for an asymmetrical valley, the evolutionary process of in-situ stress field is a circular procedure, which includes the incision of valley, the accumulation of landslides and the migration of valley.

Jan 1, 2015

By A. E. Wraith, R. Harris, J. Qiu, R. Parra

Small pilot scale experiments have shown that it is possible to almost fully eliminate the minor elements (ME), namely As, Sb, Bi and Pb contained in smelter dusts by vacuum calcination of mixtures of the dust with sulphidizing agents such as dirty copper concentrate or elemental sulphur at 900 °C and 80 +/- 30 Pa for 90 minutes. The products of this calcination are a residue comprising a purified mixture of copper containing compounds along with the gangue constituents and a high sulphur condensate comprising a mixture of the minor element compounds. In particular, the Cu:ME ratios of the concentrate and dust were increased from 250 and 50, from 28 and 12 and from 36 and 8 to roughly 3000, 3000 and 100 for the calcine, for Bi, As and Sb, respectively. It has also been calculated that (i) the copper content of the vacuum calcine may be recovered by feeding it into a Peirce-Smith converter during its slag blow, and (ii) the resulting recycling could increase the minor element treatment capacity of a smelter by 100 % while also reducing the blister As content by a factor of three. The experimental results are briefly discussed and a treated dust recycling option is examined. Example operating conditions are presented and available commercial technology for the vacuum calcination of the mixtures is reviewed.

Jan 1, 2007

By H. Harzer

Statistics Canada record s indicate that in recent years 70 to 80% of the entire Canadian coal production originated from Western Canadian mines, in which about 55 to 65% of the coals are bituminous. Until recently, less than 20% of the latter were extracted by underground methods , the remainder being surface-mined. However, it is estimated that within the foreseeable future up to 80 or 90% will have to be gained by underground techniques. Although Western Canadian coal resources are considerable, they are unfortunately locked in severely distorted, steeply pitching and faulted seams of variable thickness. Consequently, their economic extraction poses serious engineering problems. One possible solution to the problems is to apply hydromechanical methods to underground mining. This is a well-proven method shown to be economically viable under Western Canadian conditions. This paper endeavours to widen the scope of published data on hydraulic coal mining and is based on practical engineering and cost data gathered through contacts with West German designers and operators of hydraulic mines.

Jan 1, 1978

By A. Luszczkiewicz

This paper presents the beneficial effects of non-oxidative leaching of final and intermediate copper sulfide concentrates with sulfuric acid prior to the final cleaning stage of flotation. This unique process, combining leaching and flotation, appears to be advantageous for difficult-to-treat carbonate-bearing Polish copper ores, such as those processed in copper concentrators at KGHM Polish Copper. It was shown that after the chemical decomposition of about 70 % of the total carbonates naturally present in the flotation feed, a considerable enhancement of subsequent flotation results (both grade and recovery). The resulting products of non-oxidative leaching are solid hydrated calcium sulfate (gypsum), soluble magnesium sulfate and gaseous carbon dioxide. The beneficial effect established by the laboratory leaching tests was subsequently confirmed during a pilot plant operation treating final copper concentrate and a problematic intermediate concentrate at the Lubin concentrator.

Jan 1, 2007

By J. W. Matousek

The heat content of the waste slag from a typical smelting operation methods for estimating the thermodynamic properties of smelting slags, to include: -- heats of formation -- heat capacities (specific heats) -- heat contents -- melting temperatures -- heats of fusion The techniques are illustrated with the analyses of a nickel reverberatory furnace slag from Copper Cliff, an iron-making blast furnace slag, and a "lateritic" slag from a ferronickel operation in Colombia.

Jan 1, 2007

By S. P. Lowe

Introduction In the following pages a general description is presented of the concentrator and cyanide plant of the Hudson Bay Mining and Smelting Company, Limited, at Flin Flon, Manitoba, together with some account of the steps which have led to the adoption of the present practice. For an account of the preliminary test-work and pilot-mill operation, the reader is referred to a recent paper by R. E. Phelan on the History of Flin Flon Mine up to Construction (1). Additional notes may be found in a paper which the writer presented at the Annual Meeting of the Institute in 1930 (2). The first ore was crushed in the present plant on July 1st, 1930, and the first ball-mill was started one month later, on August 1st. Since that time, production has been continuous with the exception of one month lost during a strike in the summer of 1934. There have been no major changes in equipment or methods of treatment since the present plant was built, but many minor changes have contributed to the improvement in results obtained and to the increase in capacity to the large tonnage now being milled. The accompanying flow-sheets indicate the equipment used in the several plants, with the average life and repair cost. As originally built, the concentrator was to treat 3,000 tons per day, but the capacity has been increased to 4,400 tons. The methods adopted to make possible this increase in tonnage will be referred to below. It was the intention to produce two classes of ore: (1) a heavy sulphide, and (2) a disseminated ore. The mill was consequently divided into two sections, each adapted for most efficient treatment of one particular type of ore. However, it was soon found that it would be impossible to mine the two classes of ore separately, so it was decided to treat open-pit ore, which varies greatly in character, in the sulphide section, and underground ore, which is fairly constant, in the disseminated section. This segregation is still maintained.

Jan 1, 1935

By S. M. Bradshaw, E. Charikinya

"Microwave induced cracks have the potential to enhance metal recovery from coarse sphalerite particles in heap leaching operations by creating new crack surface areas for lixiviant and enhancing value mineral exposure. The mode of fracture and the extent of mineral exposure due to microwave induced cracks have not yet been investigated. The objective of this study was to determine the extent of particle damage and mineral exposure in microwave treated particles. This was done using X-ray computed tomography (XCT) and image analysis techniques. XCT analysis was conducted on small (–5+4.75 mm), medium (–16+9.5 mm), and large (–25+19 mm) sphalerite ore particles before and after microwave treatment (MT). Geometrical properties, such as volume and surface area of each mineral phase in each particle was determined from the XCT reconstructed images using VGStudioMax image analysis software. These geometrical properties were used to calculate the interfacial areas of sulphide mineral grains in microwave treated particles before and after MT. The ratio of specific interfacial area after MT to specific interfacial area before treatment was used as an indicator of the degree of preferential grain boundary fracture. The results showed significant grain boundary fracture after MT at all sizes. For small sized particles, about 31% of the interfacial area was lost compared to 23 and 16% for medium and large particles, respectively. The results also showed an increase in the degree of mineral grain exposure of 28, 26, and 15% for small, medium, and large particles, respectively, after MT. These results provide experimental evidence supporting improved mineral exposure due to MT. INTRODUCTIONFor some years it has been suggested that microwave treatment (MT) of ores might result in preferential grain boundary fracture that would have benefits such as improved grain exposure and particle weakening. (Kingman, 2006). Most of the experimental work investigating the application of microwaves to mineral processing flow sheets has focused on assessing the benefits of applying microwave technology to flow sheets consisting of size reduction and mechanical flotation cells (Kingman et al., 2004). Experimental studies have shown that coarse crushing during tertiary grinding of microwave treated ore resulted in a better liberated coarser flotation feed (Scott, Bradshaw, & Eksteen, 2008). It has been suggested that improved liberation in milled flotation feed, was due to the presence of grain boundary fracture in microwave treated particles. However, this improvement in coarse particle liberation does not necessarily translate to a significant improvement in downstream flotation recovery (Kobusheshe, 2010). This is as a result of the size limit to the flotation of coarse material, due to detachment forces acting on particle-bubble aggregates, which increase as the particle size increases (Jameson, 2012). Current conventional, mechanically agitated flotation cells are not designed to float coarse material (Jameson, 2012). Hence it has been difficult to show the downstream processing benefits of applying microwaves to ores processed by comminution followed by flotation (Kobusheshe, 2010). It is clear from investigations carried out so far that inappropriate downstream exploitation of microwave treated ore would fail to realise a meaningful process benefit (Kobusheshe, 2010; Ali & Bradshaw, 2011)."

Jan 1, 2016

By D. J. McCulla

Mineral development and utilization affect the health of the economy and the pattern of long-term development throughout Canada. There are many diverse opinions on the contribution of minerals to the economy, but there is a dearth of adequate quantitative information. This paper discusses some recent research and provides some new information.

Jan 1, 1977

By Jie Li, Xinyu Liu, Yan Chen, Linjian Ma, Yasong Wang

Nonlinear time-dependent response analysis of salt cavern under extreme loads in disaster mode is of great importance to the safety and disaster prevention of gas storage group. Uncontrolled blowout is one of the extreme conditions for compressed-air cavern operation. Based on the geological structure of Jintan salt deposit, China, the numerical model of the complete process of water solution, cyclic operation, and internal pressure runaway was developed. The effects of rapid unloading on the stress filed, the progressive failure of surrounding rock, the volume convergence of storage cavern, and the ground subsidence were simulated employing an elasto-viscoplastic damage constitutive equation for rock salt. The results indicate that the damage and failure zones propagate much larger in the mudstone interlayer than in the host salt. The volume of damage and failure zones surrounding salt cavern induced by unloading process is 5~6 times that of cyclic injection and withdrawal process. The average volume convergence rate of salt cavern reaches 0.012%/d~0.013%/d, which is 6~6.5 times that induced by cyclic operation. The ground subsidence exhibits a typical funnel curve. The affected region of ground subsidence due to rapid unloading in the blowout period is about two times the maximum cavern diameters. Furthermore, double cavern analysis reveals that the interaction between adjacent caverns may be ignored so long as the pillar width is larger than two times the maximum cavern diameters.

Jan 1, 2015

By Jonathan Ruiz Lizardo, Met-Chem Canada Inc., Flavio Ccuno, Constante Umipig, Ewald Pengel, José Ruiz

"Cerro de Maimón is located in the Dominican Republic on the island of Hispaniola approximately 75 kilometers northwest of the capital city, Santo Domingo. The processing facility consisted of two separate processing plants for oxide and sulphide ores. The oxide plant processed oxide ore bearing gold and silver ore using cyanide leaching and Merrill Crowe processes, while the sulphide plant produced a copper concentrate using conventional flotation. Cormidom is a commendatory example how mineral processing facilities can co-exist in balance with the environment. In 2014, natural occurring copper oxide contamination with finer grained copper-zinc sulphide mineralisation was expected to dominate the sulphide ore body. In anticipation Cormidom contacted the original plant designer Met-Chem to assist in overcoming this challenge. Test work indicated that increased flotation time and subsequent very fine grinding were required. Met-Chem provided the detailed engineering and Cormidom proceeded with the expansion project internally. Currently Cormidom has processed the sulphide ore successfully by implementing flotation modifications. This paper describes the history of Cormidom, test work on the “new” ore body, modification in process design in the Cu-Zn sulphide flotation circuit, construction and implementation.INTRODUCTIONCorporación Minera Dominicana (CORMIDOM) was a wholly owned subsidiary of GlobeStar Mining Corporation (a Canadian based minerals exploration company) with extensive exploration of base and precious metals in the Dominican Republic. In 2007-2008 CORMIDOM constructed the Cerro de Maimom project. The company was subsequently sold and purchased by Perilya Limited from Australia in 2013. Cerro de Maimón is located in the Dominican Republic on the island of Hispaniola approximately 75 kilometers northwest of the capital city, Santo Domingo. It is near the town of Maimón in Monsenor, Nouel Province (see Figure 1)."

Jan 1, 2016

By T. S. Smith

INTRODUCTION IN PREPARING this paper for the District 4 Meeting, three factors had to be considered. First, the paper must fit the time alloted; second, it must give a general picture of the geology for those unfamiliar with the property; and third, it must contain some new material in order to be of interest to local delegates. The most comprehensive extant discussion of the geology of the property of McKenzie Red Lake Gold Mines, Limited, is contained in Horwood's report on the general Red Lake area ( 1). This report is the 'bible' of the area, and a general paper on the geology of this particular mine would almost certainly appear to be a condensation of it. It was thought, therefore, that the most suitable procedure would be to base the general outline on Horwood' s report, to extend that outline where possible from information gained since its publication, and finally to leave dangling for the contemplative geologist some of the ideas and problems which ?are currently under consideration. LOCATION AND HISTORY The property of McKenzie Red Lake Gold Mines, Limited, is in Dome township, in the Red Lake mining division of northwestern Ontario. The mine is on McKenzie Island, about four miles north, by water, of the Hasaga mine and old Howey mine.

Jan 1, 1951

By Thomas Mütze, Frank van der Meer, Gunnar Kretschmar

"The air classification of moist bulk materials is addressed in the literature insufficiently. Therefore a feasibility study investigated the influence of feed moisture on the separation efficiency expecting a reduction with higher moisture content in the feed. Two iron ore samples were characterized in terms of the nature of bonding of moisture as well as its effect on the agglomerate strength. The classification tests themselves were conducted with two dynamic laboratory air classifiers at cut sizes from 45 to 110 µm and a moisture of the feed material between 0 to 10 wt.-%. The quality of classification was assessed by split factor, cut size, separation efficiency, moisture of both products, as well as the yield of the fines as product fraction in a corresponding processing plant. An initial approach was found for a technological implementation: A sufficient drying of a moist feed can be realized simultaneously to the pneumatic transport inside the classifiers. In the present case the drying effect and dispersion intensity was sufficient to provide good separation results up to 3 wt.-% feed moisture. An additional drying step was necessary beyond 3 wt.-%.INTRODUCTIONSpecific information about the influence of moisture in air classifiers is very rare. Mostly only dry products are processed and/or drying prior to classification is recommended. Apart from the specific influence of the feed moisture a lot of literature can be found regarding air classification itself. Altogether air classification can be divided into several sub-process (Leschonski, 1977):- dosage of the feed material,- dispersing the solid feed material into a gas stream,- feeding the dispersed material into the classification zone by pneumatic conveying,- separation of coarse and fine particles, and- separation of fine particles from gas.For wet feed particles also drying plays an important role. Interesting for the present investigation are the humidity of the feed and its influence on the single sub-processes."

Jan 1, 2016