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By J. W. G. Hannon

FOLLOWING the experimental work of Denny, Robson, and Irwin, and the clinical investigation by Crombie and Blaisdell, an investigation of aluminium therapy was begun at Washington, Pa., which is situated in a very large industrial section of the State. Some of the men to be studied were from plants manufacturing silica brick, refractories used in steel and glass manufacturing, and semi-porcelain table-ware; others were workers in foundries, sand blasters, and men engaged in the quarrying of ganister rock. This group of workmen gave an opportunity to study the effects of aluminium on various types of silicosis which differed somewhat from that found in hard-rock miners. EXPOSURE In their occupations, the men studied were exposed to silica dust concentrations ranging from 17 to 97 per cent free silica. In the silica brick industries, the unfired product averages 96 per cent silica in the form of quartz, whereas the fired brick contains 50 to 62 per cent cristobalite plus 17 to 30 per cent tridymite, forms of silica that, on account of their higher solubility, are more toxic than quartz. The operational dust counts in the plants varied from 15 to 9,500 particles per c.c., and the median particle size from the aerial samples was 1.0 micron for the green product and 2.0 microns for the fired product. The length of exposure varied with the occupation as well as with the individual plant, but disabling silicosis could be produced in less than four years in certain exposures. The average time needed to produce radiological silicosis in those susceptible to this disease was eight years. Some of the men in our series of cases have been treated as long as fifteen years after exposure had ceased, and have improved under treatment.

Jan 1, 1944

By S. D. Tolgyesi

Kidd Creek Background ? Located in Northern Ontario, Canada ? Underground base metal mine ? Operating since 1966 ? Total of 125Mt mined to date (2.43% Cu, 6.60% Zn) ? Current plan at 2.4Mt/Y (6575t/D) Current Practices ? Evaluating stope margins to ensure that value is added ? Scheduling sulphide and Cu stringer ore to limit oxidation in passes ? Scheduling to maintain uniform grades to concentrator ? (SOPs highlight problem stopes on mine plans, and limit blast sizes in those stopes which may contain sulphides prone to oxidation) ? Scheduling high-Pb stopes to avoid spikes to concentrator ? Providing weekly, monthly and long-term forecasts ? Reconciling mine and mill production ? Underground grade and dilution estimates by mine supervision ? Terminate mucking when grade becomes sub-economic ? Laser cavity surveys to provide feedback and improve Designs Cut-off Grades ? Ore value is obtained from copper, zinc and silver ? Ore outlines at 2% copper equivalent used to guide stope planning; sulphide outlines obtained from contacts while copper stringer outlines drawn from block model (kriged) ? Datamine block model and CADD software used to evaluate alternative stope shapes ? Stopes classified as waste, incremental, or full-cost based on margin calculations for each stope ? Incremental ore may be mined if it does not displace fullcost Ore Conclusions ? Grade control remains an important function for optimizing the ore extraction at Kidd ? The scope of the function has changed to a scheduling focus ? A change in grade control practices over time has not led to significant changes in concentrator feed ? The lead and iron sulphide content of the ore display upwards trends and may require more attention in the future ? The key function of field observations has shifted to flagging exceptions and terminate mucking at grade cut-off

May 1, 2003

By E. J. Burrough

MR. J. J. McIntyre (International Coal & Coke Company, Ltd., and McGi1livray Creek Coal & Coke Company, Ltd., Coleman, Alta): Mr. Burrough's excellent paper, Metallurgical Coals of the Crowsnest Area, seems especially timely now, when the need for developing iron industries in the west, as well as in the east, is receiving so much attention. His -thorough review of the 'coking' industry is an especially valuable contribution, along with which the following brief remarks on coking in the Crowsnest Pass area of British Columbia and Alberta may be in order. When the Crowsnest Pass line of the Canadian Pacific railway was built there were great expectations for the non-ferrous metal industry; quite a number of smelter's were al-ready in operation in British Columbia and the northwestern United States, and further expansion was confidently expected. The suitability of the medium-volatile coking coals of the Pass for making metallurgical coke had been recognized from the time the fields were first explored. By the time the mines were fairly well developed there was already a market to war-rant the building of coking plants, and a common belief that expansion of the market would require a large coking industry. The first coke production was from plants built by the Crowsnest Pass Coal Company, Ltd., at Fernie, B.C. in 1903, and the International Coal and Coke Company, Ltd., at Coleman, Alberta. These plants were followed by others built by the Crowsnest Pass Coal Company, at Michel, B.C., by West Canadian Collieries, Ltd., at Lille, Alberta, and by Leitch Collieries, Ltd., at Passburg Alberta, and by a plant at Hosmer, B.C.

Jan 1, 1951

By Denis J. Kemp

The 20th Century saw changes in the mining and metallurgical industry not only technically but also in social and environmental expectations. As projects continue to become larger to maintain competitiveness the visibility of their potential impacts raise concerns among many groups. The need for transparency, openness and early engagement of all parties are fundamental to assure success. An equally important task is to anticipate the standards that will be required to meet society?s expectations in the 21st Century. Historical Observations The mining industry of the 18 and 19th Century was dominated by opportunistic Companies and individuals with an entrepreneurial flair for adventure and risk. Those who promoted had the chance of great reward, while those willing to risk their life were assured a short one for their efforts because of the physical and health dangers that abounded. Disregarding conditions miners rewards were high even in those days, with an average Cornish miner known to be earning two pound a month in 1800. Coal and iron ore mines were driven by the needs of the industrial revolution and were the first to embark on larger scale output. Base metal mines were smaller as industrial demands for their use did not start to expand greatly till the late 19th Century. Electrification, the automobile and the 1st World War drove the increased demand for a variety of metals. Early mines were foul smelling and dusty and what was taken from below ground left spoil piles around the surface countryside after recovery of the coal or concentrate. The image of barren blackened hills is one that is easily conjured up and is an environmental legacy that still lives with us today.

May 1, 2002

By A. Bhowmik

Uranium Refining is the process in which undesirable neutron absorbing elements such as Boron (B), Gadolinium (Gd), Cadmium (Cd), Europium (Eu), Samarium (Sm) and other heavy metals (Fe, Ni, Co, Ca, Mg etc.) are removed to make it nuclear pure. At present, Uranium refining is carried out by solvent extraction process by using organic based solvent e, g. TBP diluted with Kerosene. The above process generates lot of nitrate bearing liquid waste and degraded organic. In order to eliminate use of hazardous organic and ammonia for Uranium refining altogether, a new process has been developed. In the new process, Yellow Cake is dissolved in nitric acid and uranium peroxide hydrate is precipitated selectively from the solution leaving all the impurities in the solution by using commercial grade hydrogen peroxide at a pre-defined pH, U conc., temperature and stoichiometric quantity of hydrogen peroxide under mild agitation. The precipitate is filtered and washed with DM water to obtain nuclear pure product meeting purity standard as per ASTM C ? 753-99.The product is spray dried and calcined to obtain uranium oxide. The process eliminates use of organic, flammable, toxic chemicals, consumes less quantity of nitric acid and uses environfriendly chemical hydrogen peroxide. The process is simple and can be integrated in the mill. A patent application is entering national phase in several countries including CANADA and abstract/full paper is available in WIPO publication no: WO/2009/013759.

Aug 1, 2010

By Ahmad Hemami

A working code is developed to simulate the forces that are involved in the process of penetration of a bucket into bulk media during loading and excavation. The result of this work can be integrated with the simulation software that many manufacturers of heavy earthmoving machines introduce for training purposes. The simulator programs for machines such as backhoes, loaders, LHDs and the like, used for operator training, are usually only based on the kinematics of the machine. As a result, there is no indication of the effect of the medium when the cutting tool of such a machine touches the excavation material. This is like moving the machine in the air. Feeling the resistance force of medium to cutting by a bucket or blade during loading and excavation is more realistic, both mentally (by vision) and physically (feeling resistance in pedals and levers). The results from force simulation can be used by feedback in creating simulated resistance in these training gears, similar to what is done in flight simulators for aircrafts. In addition to serving for the above purpose, the results of this work can be used as a tool for examination and verification of the effect of a control policy for automation of loading and excavation of bulk media. So far no commercial product has been introduced that has such a capability, despite some extensive research on the subject.

Aug 1, 2013

By Rodolfo Zanella

Au/TiO2 catalysts were prepared by deposition-precipitation using NaOH (DPN) (~3 wt % Au) and urea (DPU) (~8 wt % Au), and calcined at various temperatures between 100 and 400 °C. They were characterized by UV-Visible, XANES, EXAFS and TEM. Their activity were tested in the reaction of CO oxidation at 5°C. After preparation, the gold species are in the oxidic state III. They begin to transform into metallic gold under air at ~100 °C for DPN and ~150 °C for DPU. At 200 °C, all the gold is metallic for the two preparation methods. The particle size increases from 1.5 to 3.5 nm with the calcination temperature. The catalytic activity for CO oxidation increases with the percentage of metallic gold, and it is maximum at 200°C for both types of samples. The activities (per mole of Au) are the same for the two types of catalysts. At higher temperatures, the catalytic activity drops. The decrease of activity is mainly due to a change of particle shape with the calcination temperature rather than to the increase of the particle size. At a calcination temperature of 200°C, the particles present small facets with rounded parts, and their outer surface contains a large proportion of low coordinated sites (steps and corners) while at high temperature of calcination, they are truncated octahedra with smooth facets.

Oct 1, 2003

By J. B. Sabey, V. R. Degner, D. MacGillivray

"Hydrodynamics principals are applied to the design of a natural air ingestion flotation machine for coarse solids applications. Preliminary laboratory test data and subsequent operating plant flotation kinetic performance evaluations are reviewed. INTRODUCTIONThe concentration of potash (sylvite, KCI) from halite and other salts using flotation is well understood and practice a with much success. Reagent schemes and plant circuitry for obtaining the desired product recovery and grade have been established with proven performance. These flotation circuits normally process the medium and finer size particles, less than 30 mesh (600 microns).However, often the potash market trends specifically demand a coarse product size. This emphasis, accompanied by the existing high losses of coarse (+30 mesh) potash in flotation circuits, creates the need for development of a flotation machines specifically designed for coarse potash beneficiation.This technical challenge was undertaken by the WEMCO Research and Development Group. The specific objectives of this flotation machine development program were ( l) to achieve an ""Ultra Coarse Flotation Machine"" capable of adequately suspending and transporting particles in the 4 - 30 mesh (4.75 - 0.6 mm) size range at solids concentrations of 30% or greater and (2) ascertain metallurgical performance of this machine.This paper covers the development (both theoretical and mechanical/ hydrodynamic), the field test program and results, a discussion of applicable flotation kinetics, and conclusions of this ""Coarse Potash Flotation Machine"" development project."

Jan 1, 1986

By C. Diaz, S. W. Marcuson, K. I. Burgess

Deep roasting in fluid bed roasters is the first unit operation in Inco&apos;s "roast-reduction smelting" process for the treatment of nickel sulphide concentrates. The roaster product, a low sulphur calcine, is reduction smelted with coke in an electric furnace to yield a sulphur-deficient matte which is then converted to low (<1%) iron matte in Peirce-Smith converters. Due to the deep roasting, a minimal amount of sulphur dioxide is evolved in the smelting and converting stages. Sulphur is eliminated from the concentrate almost exclusively in the roasters in a single, continuous, strong, gas stream suitable for treatment in an acid plant. This paper discusses the commercial scale testing of deep fluid bed roasting of nickel concentrate at Inco&apos;s Thompson Smelter as part of two commercial scale campaigns on roast reduction smelting conducted in 1981-1982. Slurry feeding, practised during the second campaign, permitted excellent control of the air/concentrate ratio in the roaster and, in turn, good control of sulphur elimination (about 80% of input). Smooth autogenous operation with high oxygen efficiencies (about 95%) was promoted by operating at bed temperatures of830°C to 850°C with calcine recycle. High throughputs and the desired metallurgy were achieved. The extensive testwork conducted during the two experimental RRS campaigns demonstrated thot deep fluid bed roasting of nickel concentrate at high oxygen efficiency is a technically viable operation.

Jan 1, 1994

By Donald Brisebois

The mining of high-grade, narrow vein deposits is an important field of activity in the precious metal mining sector. The principle factor that has undermined the profitability and effectiveness of mining such ore zones is the substantial dilution that occurs when blasting with explosives during extraction. In order to minimise dilution, the Thermal Fragmentation Mining Method enables the operator to extract a narrow mineralised corridor, 50 cm to 1 metre wide (according to the width of the vein), between two sub-level drifts. By inserting a strong burner powered by diesel fuel and compressed air into a pilot hole previously drilled directly into the vein, a thermal reaction is created, spalling the rock and enlarging the hole to 80 cm in diameter. The remaining ore between the thermal holes is broken loose using low powered explosives, leaving the waste walls intact. This patented method produces highly concentrated ore, resulting in 400% - 500% less dilution when compared to conventional mining methods. The mining method reduces the environmental affects of mining operations since much smaller quantities of rock are displaced, stockpiled, and treated using chemical agents. The fully mechanised equipment operated by a 2-person team (1 thermal fragmentation operator, 1 drilling operator) maximises the effectiveness of skilled personnel, and increases productivity and safety. The Thermal Fragmentation is currently employed in 3 mining operations in North America.

May 1, 2010

By G. Vibert Douglas

It has long been recognized that there are considerable difficulties connected with the physical and chemical explanation of shoots of ore. The literature of Mining Geology has frequent references to this subject; but the reasons given for the actual location of primary ore-shoots have been very tentative. In practice, the geologist or miner depends to a great extent on sampling and assaying to determine the boundaries of profitable ore within the mineralized zone. An ore-shoot is a portion of a mineralized zone which has a sufficient concentration of valuable minerals to make it ore. Ore deposits have been classified according to many schemes. There are classifications based on morphology and on genesis. However, it is also possible to classify hypo-gene hydrothermal ore-bodies in terms of ore-shoots or vice versa. A.-Ore-deposits in which the whole of the mineralized zone is ore, which is the same as saying that the ore-shoot extends throughout the mineralized zone. An example of this type of deposit would be the pyritic mineralization of Rio Tinto. B.-The second type would comprise those deposits in which the ore-shoots bear some relation to the geological structure of the area: all deposits in which &apos;bonanzas&apos; occur in folds in the zone, at the intersection of veins along certain fault (or joint) features and other such controls. There are a great many examples of this type: (a) The Rhodesian copper lodes, where Bancroft and Gray have pointed out the association of the shoots of ore with drag folds. (b) A similar association has been pointed out by Faribault for some of the gold veins of Nova Scotia, e.g., Mount Uniacke. (c) The great bonanza of the Comstock lode in Nevada. C.-Deposits in which the localization of ore has been effected by the chemical character of the wall-rock. Examples of this type are the Fahlbands of Scandinavia, and the &apos;indicator&apos; deposits of Ballarat, Australia. D.-Lastly, deposits in which there is apparently no structural and no chemical control.

Jan 1, 1934

By T. Motegi

Semisolid casting provides grain refinement of the cast structure and prevents macro-segregation. The conventional semisolid slurry is obtained by electromagnetic or mechanical stirring. In our process, the magnesium alloy (AZ31) slurry is made using an inclined cooling plate instead of the conventional methods. The slurry obtained is cast into a twin-roll caster and makes a continuous sheet of 2 or 3 mm thick. The most important factors that influence the sheet casting are the casting temperature and twin-roll speed.

Jan 1, 2007

By P. J. Mackey, Elsie Kossatz

The small town of Bruce Mines lies a few miles east of Sault Ste. Marie, Ontario on the north shore of Lake Huron. This was the site of the first copper mine. This copper smelter used a reverberatory furnace, based on the Welsh process, and operated in the period of 1849 to 1850, when the plant was destroyed by fire. During the period of 1850 to about 1869, crushed and sorted ore was shipped to England and later to the United States. In 1869, a roastleach plant, based on the Henderson Process, was constructed at Bruce Mines and was operated until about 1872. This short article describes the early development of this historic operation. Although the rich copper ore found in the vicinity of Bruce Mines was known to the Indians, its discovery in or about 184 7 was credited to Mr. Keating, who named the area Bruce in honour of Lord Elgin (James Bruce), Canada&apos;s Governor General. In 1848, the property was acquired by the Montreal Mining Company for 40 000 pounds sterling and the company immediately sent a small party to investigate the deposit. The party sank a shaft on a lode within a hundred yards of the lake and also reported two adjacent lodes farther inland, which were left undeveloped until the turn of the century. Initially, the foundation of the headframe and hoist was built above the frost line and when the machinery was set in motion it collapsed. Eventually, the shaft was to reach a depth of 300 feet. By 1849, the property was well established and the small settlement consisted of 77 miners, 65 labourers, 4 boys, 11 tradesmen, including blacksmiths and carpenters, 2 mining captains, 1 engineer, 2 clerks and 1 superintendent. The community, including the workers&apos; families, numbered about 250.

Jan 1, 1999

By M. Massinaei

Recently constructed circuits have included multiple stages of columns in a variety of applications, from roughing to cleaning. The Miduk copper concentrator (in south-eastern Iran) is one of the unique mineral processing plants which use column flotation cells as rougher. As the bulk of final concentrate is produced by rougher columns, optimized metallurgical performance of these cells is crucial. This paper will present the study and optimization of, a froth washing system of columns. For this purpose, the cross-sectional area of orifices was increased and their orientation altered. Concentrate assay for copper and silica, in addition to bias rate were found to be the assessment criteria. Modification of the wash water system resulted in increasing the purity of rougher and final concentrate. Negative bias and short-circuiting of wash water into the concentrate launder were the main causes of improper froth zone washing in the former system.

Jan 1, 2007

By Karen I. McMaster

"Abstract - The mining industry has endorsed the concept of sustainable development in principle. We now need to ensure that it is "lived" throughout the workplace. Frequently, sustainable development is viewed as just a policy and, more often than not, it is regarded as something that is applicable only to the areas of health and safety, environment, or community philanthropy. However, sustainability requires the collective action of an entire organization on a regular basis, a corporate culture where values are transformed into action.This paper reviews two of the many functional areas through which sustainable development can be pursued. Law and internal auditing are powerful means of instilling values, driving behavioral change, and improving performance. The development and role of each tool vis-a-vis sustainability is reviewed. Suggestions are offered regarding option and joint venture agreements, contract management programs, and various auditing programs based upon international standards and processes, market indices, and codes of conduct.The goal of this paper is to provide a general overview of these functional areas and to encourage further dialogue between employees and management in the workplace. It is hoped that others in the industry will examine the values of their companies, and review the ways in which individuals in all functional areas work, or want to work, on a daily basis. If we can harness collective commitment, creative thinking, and action in sustainable development, then the desired acceptance by stakeholders and improved financial performance will follow."

Jan 1, 2003

By L. Louis

High resolution X-ray computed tomography imaging (with voxel size 48 µm) was conducted on various sandstone samples with different initial degrees of heterogeneity. All samples were imaged intact, and some after having developed localized compaction features in conventional triaxial experiments at high confining pressure, i.e. in the shear enhanced compaction domain (Wong et al., 1997). Our analysis of heterogeneity from X-ray CT data is based on the use of the coefficient of variation d =s /µ (s being the standard deviation and µ the average value). The coefficient of variation was shown by Otani et al. (2005) to be a convenient indicator of material heterogeneity in CT images of experimentally deformed sand piles. The authors reported differences in d before and after their experiments, and interpreted these differences as the effect of grain crushing resulting in more even material distribution within the voxels, hence in lower d values. The same concept was used by Louis et al. (2006) to image contrasts in d values throughout a volume of rock that had developed compaction bands in triaxial laboratory testing, knowing that the bands that had formed could be identified by visual inspection but not on the X-ray CT images. This study resulted in a radically enhanced image of the discrete compacted zones within the CT-scan series, whereby more deformed areas showed relatively low values of coefficient of variation due to grain crushing and pore collapse, as compared to nominally undeformed areas.

May 1, 2009

By C. Graham

Mechanisation has been a predominant theme of the past 50 years in the mining industry, particularly underground mining. As the level of technology employed has increased, the anticipated productivity gains have not been realised and the differences are not explained by the demand for higher standards of safety and security. Now, mining costs are so high and productivity so low that the resultant return on investment for many Canadian operations has fallen to levels considered unacceptable in a competitive capital market. Simply continuing technological development cannot reverse this trend and its financial implications. The focus on technological development has distracted us from some basic truths. Systems that are more complex are more likely to fail and cost-effective processes depend on the continuity of productive activity and the flow of material. When putting these facts together, it becomes clear that in a system that has fixed external conditions, the single most crucial issue is the effective management of the operational cycle. By its nature, technology focuses our attention on what gets done and how it gets done, while the crucial issue is the increasingly longer periods in the operational cycle when nothing productive is being done. What is required is to match the level of technological complexity to the fixed system conditions, which are virtually unchangeable. This paper looks at the overall system and objectives and attempts to present an appropriate level of technology for the Canadian mining industry, now and in the foreseeable future.

May 1, 2004

By Janne Karonen, Stephen Hughes, Mikael Jåfs, Jan Stål, Hannu Johto

End-of-life electrical and electronic scrap material attracts attention as a good opportunity for new value creation through efficient metal and energy recovery of such materials. On the other hand, the treatment of such wastes becomes important to avoid problems for society and environment. Treatment of such secondary raw materials faces multiple challenges due to their increasing complexity and evolving nature. Processing of these complex scrap materials together with recovery of a wide range of valuable metals with a combination of pyrometallurgy and hydrometallurgy using Outotec technology is discussed in this paper. One key consideration is environmental performance which needs attention when processing such complex secondary E-waste materials. Outotec has successful experience with commercial projects in the countries at the forefront of environmental and operational standards. INTRODUCTION Increasing attention has been drawn to the responsible processing of end of life Waste Electrical and Electronic Equipment (WEEE) as part of metals recycling, especially copper. It has been estimated that the amount of WEEE globally in 2016 was around the level of 46 Mtpa (Balde et al., 2017), representing a major disposal challenge but at the same time huge opportunity for resource recovery. The potential for increasing the recovery is high, because the official recycling rate of WEEE is in 2016 only 20% (Balde et al., 2017) and at the same time the estimated increase of the WEEE amount is between 3 and 5% per annum in the EU (Eurostat, 2019).

Jan 1, 2019

By J. Keith Haddock

"IntroductionThe Bienfait Mine is operated by Bienfait Coal Company Ltd., one of the Luscar Limited group of companies. Situated 5 km southeast of the town of Bienfait, Saskatchewan, it can produce 2.0 million tonnes of lignite annually in addition to 158,000 tonnes of char from a carbonization plant located on the property. Geology The economically mineable coal seams of the Estevan area are found in the Ravenscrag Formation. The lignite-bearing sands, silts and clays were deposited in Early Tertiary age, in an inland sea centred in the Williston Basin of North Dakota. The top of the Ravenscrag is an erosional surface, overlain by Tertiary or Quarternary sands and gravels or glacial till. The regional structure is a gently plunging syncline which dips to the southeast at about 0.3 degrees. There are minor undulations in the Bienfait area which are due to differential subsidence during deposition. Sporadic faulting is probably a result of glacial pressures, and preglacial and glacial channels are responsible for washout zones and the abrupt irregular subcrop found in the area. There are two economic coal seams in the Bienfait area, an uppe; seam locally known as the Roche Percee, and a lower seam, the Estevan. Both seams have been extensively mined since lignite mining began in the area in the late 1800s. The Roche Percee remains only in a small portion of the Bienfait Mine and comprises a very minor portion of the reserves. It averages 1.74 m thick under 8.1 m of overburden. The till rests on top of the Roche Percee and due to weathering the seam is generally of poorer quality. The Estevan seam comprises the majority of reserves at Bienfait. The main seam which is being worked on consists of an upper bench averaging 2.75 m, a carbonaceous parting of 0.21 m, and a lower bench of 0.92 m. Overburden depth above this seam varies from 21.0 m to 38.0 m."

Jan 1, 1985

By M. Hajian Heidary

In this investigation, effect of pressure depth on the globulizations of AZ91 magnesium alloy was studied. Cylindrical samples of AZ91 alloy with 1 cm and 2cm in height and 2.5cm in diameter (H/D = 0.4 and 0.8) were prepared, then the samples were hot pressed at 10 and 30% strain at a constant temperature of 200°C; subsequently reheated at 555°C in different times. Results obtained from optical microscopy (OM) showed that the thickness of the samples and consequently, depth of strain affected regions have remarkable effect on the degree of globulization. In addition, it was found that at a constant strain and holding time, structure of thinner samples is more globular than thicker ones.

Jan 1, 2007