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By J. Qi

Based on the commercial steel 42CrMo (4140, SCM440), a new generation of CrMo steel was developed by increasing the content of Mo, adding the alloy element of V and Nb, and decreasing the content of P and S. This new CrMo steel has higher strength of 1500MPa and better delayed failure property. TEM and EDS were used to study the distribution and function of the alloying elements in this steel. A new EELS technique was developed to study the bonding strength of the grain boundary in the steel. The mechanism of strengthening of the new steel has been studied.

Jan 1, 2004

By G. E. Bogin, C. Strebinger, J. F. Brune

"Evidence shows that methane gas emanates from the mined-out area or gob of a longwall coal mine and can travel towards the working face, posing an explosion risk. Since the gob consists of varying levels of compacted rock, many researchers have modeled fluid flow through the gob as a Darcy-type porous media with a specified porosity and permeability. When studying methane gas explosions near the gob fringe, the Darcy flow assumption may not be applicable to describe the methane flame interaction with the gob. Computational fluid dynamic studies were performed modeling methane flame propagation across a simulated gob which was modeled as both a Darcy porous medium and as discrete rock objects with varying sphericity. Modeling the gob as a Darcy porous medium results in unrealistic methane flame propagation since the porous media assumption does not consider any differences in rock size and/or distribution. Additionally, the porous media model does not allow for ignition within and subsequent flame propagation through the porous medium, which must be modeled to understand the potential for methane gas explosions in the gob area. Modeling the gob as discrete rock objects produces more realistic methane flame dynamics and agrees with experimental observations. Modeling results show flame propagation across circles, hexagons, and squares, meant to represent rock rubble in the gob, produce different levels of turbulence which affects methane flame propagation velocity. This research demonstrates that modeling methane gas explosions in a longwall coal mine environment, specifically near the gob area, requires modeling obstacles, such as rock rubble, as discrete physical objects to capture the complex coupling of fluid dynamics, thermodynamics, and heat transfer. INTRODUCTION Although there are methods to mitigating methane accumulations in a longwall coal mine, explosive gas zones (EGZs) of methane and air may exist and pose an explosion risk to nearby miners and equipment (Brune, 2014) (Karacan, Ruiz, Cote, & Phipps, 2011). In the event of an explosion, the resulting methane flame and pressure wave can be catastrophic as evidenced by the Upper Big Branch explosion in 2010 that killed 29 miners (Page, et al., 2011). Since the mining process is transient, it is difficult to determine exactly where these EGZs exist, but investigative reports show in many cases, these EGZs can be near the working face, behind the shields, or within the gob area (Brune, 2014) (McKinney, et al., 2001). Additionally, miners have recounted seeing flames moving back and forth within the gob and under the roof supports (McKinney, et al., 2001) and in other cases, anecdotal evidence of hearing small pressure pops deep within the gob area (Brune, 2014)."

Jan 1, 2019

By G. D. Ruttan

"LYNN LAKE, in northern Manitoba, has become Canada's second nickel-producing area. The discovery by Sherritt Gordon Mines of nickel ore in an entirely new district was the result of systematic prospecting of a belt of volcanics and sediments situated 100 to 150 miles north of the Company's former copper-zinc mine at Sherridon, Manitoba.Prospecting in this area was begun in 1937 and continued each year until 1941, when Austin McVeigh, a company prospector, found a patch of sulphides on a gabbro outcrop near a small lake named Lynn Lake. Samples from this sulphide indicated nickel and copper in significant amount. In 1943, magnetometer work disclosed a number of weak anomalies in low ground near the discovery. In 1945, staking was followed by geophysical surveys and diamond drilling, which continued through 1947. During this period the A, B, E, EL, and Corebodies were located and partly outlined. The discovery of the high-grade ""EL"" orebody in January 1947 was the turning point in the estabishment of the mine. Subsequent development, including additional exploration on surface and under-ground, evolution of a new metallurgical process, financing, erection of a mining and milling plant, hydro-electric power development, building of a rail line from Sherridon (by Canadian National Railways) and a refinery at Fort Saskatchewan, Alberta, culminated in August 1954, when the first shipment of nickel left the refinery. This paper, presented at the 1955 Annual General Meeting of the C.l.M. in Toronto, was one of a symposium covering the whole operation."

Jan 1, 1949

By Nelson Hogg

"THE NOR-ACME gold mine is located close to the north shore of Snow Lake, at 54°53' north latitude and 100°03' west longitude. It is about 75 air miles east of Flin Flon, and 36 miles by road from Wekusko at Mile 81 from The Pas on the Hudson Bay Railway.The claims which contain the Nor-Acme orebodies were staked in 1927 by C. R. Parres, who, with his sons, held the ground until 1938 when Nor-Acme Mines Limited was incorporated. In 194 l, on the recommendation of F. Ebbutt (1), this property was optioned by the Howe Sound Exploration Company, Ltd. A program of 50,000 feet of diamond drilling resulted in the outlining of two orebodies containing an estimated 5,000,000 tons with an average grade of 0.15 ounces per ton to a depth of 1,000 feet.A period of inactivity during the war years was followed by the construction of a mining plant capable of treating 2,000 tons of ore per day. Milling started in March 1949, and to the end of 1954 has resulted in the production of 383,793 ounces of gold and 32,906 ounces of silver from 3,331,403 tons of ore.General GeologyThe general geology of the Snow Lake area is described by J. M. Harrison (2), and will not be discussed here except insofar as it affects the Nor-Acme orebodies. The orebodies occur in rocks of Precambrian age that have been classified by Harrison as the Snow group, comprising meta-morphosed sediments interbedded with acid and basic volcanic rocks. The volcanic rocks include pyroclastic types which are unique in the region, a fact which led to their classification in the Snow group rather than the more widespread Missi group that generally occupies the same stratigraphic position above the Amisk group (Figure 1)."

Jan 1, 1949

By M. J. Nicol, C. van Wensveen

The kinetics of the oxidation of thiosulfate by copper(I I) in ammoniacal solutions have been studied in the presence and absence of dissolved oxygen. The formation of an intermediate mixed ammine/thiosulfate copper(II) complex ion has been confirmed and the rate of the reaction monitored by simultaneous on-line spectrophotometric, dissolved oxygen and potentiometric measurements. The rate of the anaerobic oxidation of thiosulfate by copper(II) was found to be orders of magnitude slower than that in the presence of dissolved oxygen and is inhibited in the presence of ammonia and anions such as sulfate and chloride as a result of competition with thiosulfate for the axial coordination sites on the copper(II) tetrammine complex. In the presence of dissolved oxygen, it was found that the copper(I) thiosulfate complexes are only very slowly oxidized while the copper(I) diammine complex is rapidly reoxidised to the copper(II) state. Thus, the initial rapid reaction with copper(II) leads to a pseudo steady-state condition in which the concentration of copper(I) is relatively constant and the rate of oxidation of thiosulfate can be predicted from the measured rate of oxidation of copper(I) by oxygen in ammoniacal solutions. The effects of the concentrations of ammonia and thiosulfate on the oxidation rate can be rationalized on the basis of the above coupled to the species distribution of copper(I) in the ammonia/thiosulfate system. It is shown that, with relatively simple measurements of dissolved oxygen and copper concentrations, the rate of oxidation of thiosulfate can be predicted under typical leaching conditions.

Jan 1, 2005

By M. S. Badollet

"IntroductionAsbestos as received by the manufacturer of asbestos products is •in the •form of either crudes or milled fibres processed to different degrees of texture. Frequently, the manufacturer finds that l:ihe fibres as he buys them are not adaptable to his plant processes, and, therefore, it is necessary for him either to contact the mine supplying the material and request a specific texture for the :fibre or to reprocess the fibre in his own plant.When the mine or mill manager is requested to change his milling equipment to produce a special grade of fibre with a specific texture, he would like to comply. However, if he began to make special fibre grades for each customer, he would be in the position of constantly rearranging his milling technique, adding more equipment, or building a new mill. In the end, his mill would he producing hundreds of different fibre grades of varying degrees of texture, which is a difficult accomplishment if he desires to maintain any quantity of production."

Jan 1, 1950

By J. W. Reynolds

Use of crushed waste rock recovered by sink-float separation from normal ore production for backfill is an established procedure at Commco's Sulhvan mme, Kimberley, British Columbia. Need for a safe method of placement in voids which were difficult to reach by gravity methods led to a co-operative venture with Radmark Engineering Ltd. in the development of a workable pneumatic transportation system for rock material. This paper reviews work done to date in a current program, and includes comments on the nature of the fill so placed, options for cementing such fill, implications for other aspects of mining and references to other applications of the system by other organizations who exchanged experiences with the Sullivan mine staff during the five-year period reviewed.

Jan 1, 1972

By Tim Gitzel

Thank you for your introduction, and thank you to the CIM for inviting me to make a presentation to you today. This is my first opportunity to report to you on the status of the Canadian uranium industry and I am pleased to tell you that the industry is in good shape, and well positioned for the future. As you will no doubt be aware, Saskatchewan benefits from the world?s largest known highgrade deposits of uranium as well as from a high level of provincial, public and northern community support. It is within this unique combination of geology and community that our industry operates. Uranium markets have been extremely competitive for a number of years for several reasons. First, deregulation in the nuclear electric power industry has tended to encourage fuel buyers to use up their large inventories built up at a time when rapidly increasing demand was anticipated. Second, alternate sources from surplus commercial stocks, military materials and reprocessed fuel have presented a major additional source of uranium supply. Today, these secondary supplies are meeting about half of uranium reactor feed requirements. Canada (that is, Saskatchewan) is the world?s largest ?natural? uranium producer with about a third of the global production. Saskatchewan?s mines produced more than 30 million pounds of yellowcake in 2002. Despite low prices, steady demand for uranium will continue. In fact, an increase in world uranium production in 2002 helped feed a more than 3 per cent increase in reactor fuel demand. Low cost production is important for surviving low market prices, but investments are based on longer-term strategies rather than simply responding to market cycles. Cost is not the only issue. In these times of increasing regulatory and public scrutiny we must continue to earn the trust of our stakeholders by adopting the highest standards and staying on the leading edge of technical, social and environmental developments. Managing these issues is as important as traditional concerns of ore grade and cost of production. The last two decades of the 20th century saw the Province of Saskatchewan rise to prominence as the leader in uranium production from facilities, which were at the time deemed world class. These facilities are now either at - or nearing - the end of their production years. We are now bringing on new facilities that will position Saskatchewan to remain the world leader in uranium production for many years to come.

May 1, 2003

By P. Nelson

Extending the campaign life of the Mitsubishi furnaces at Xstrata Copper's Kidd Metallurgical Division Copper Smelter has been a major focus of attention for many years. One aspect of this effort is real time monitoring to detect abnormal conditions and safely shut the furnaces down before significant damage occurs. Traditional real time methods of monitoring the integrity of refractory furnaces containing molten metal include alarms on individual temperatures of the refractory or cooling water. The need to set alarm limits which are not exceeded across the range of normal operating conditions leads to a system that only provides a limited warning, if any, before a failure occurs. Integrity monitoring systems that look at many different signals and alarm only changes in the relationships between the signals have been implemented on the smelting and converting furnaces. The systems are based on principle components analysis (PCA) models and implemented with the monitorMV software package. These provide much more sensitive and selective alarms so that changes in integrity are alarmed well in advance of any event. At a critical alarm level, the converting furnace is set to automatically shut down so that operating and technical personnel can review the situation. The configuration of the systems and operating experience with them will be discussed.

Jan 1, 2007

By L. Bichler

Utilizing thermal analysis techniques, pioneering research into the solidification mechanism of a popular magnesium alloy AZ91E cast by the Lost Foam Casting (LFC) process was carried out, Foam characteristics, section thickness and application of vacuum were seen to have profound effect on the cooling rate, thermal gradients and casting temperature profiles.

Jan 1, 2005

By H. Kroog

"This contribution reports recent mineral sorting experience and lists the possibilities of the newest generation of automatic mineral sorters with a special focus on electromagnetic detection, optoelectronic technology and the latest innovative X- Ray transmission units. In industry, mineral and ore are still hand-picked and current automation potential is only utilised in a handful of specific applications. Recently a number of technological developments took place that may increase sorting potential, save mill costs and lead to lower overall tonnage costs. The mentioned technologies provide automatic dry separation of minerals and rock as an alternative for conventional processing. The MikroSort technology is environmentally friendly:•,The remaining waste is free of contaminations•,The dump volume is reduced•,The concentration of the high grade material•,at an early stage saves resources"

Jan 1, 2005

By R. J. McCarthy

In-pit Crushing and Conveying (IPCC) is increasingly being considered by mining companies as a means to reduce their dependence on trucks and thus, fuel, tires, labour, etc. There is potential for great savings in operating costs which ultimately can mean better economics for a mining project. Vale has considered the application of IPCC at its Moatize coal project in Mozambique. Up to three studies have been conducted with the latest, at a pre-feasibility level, showing some promise. This paper explores the mine planning and IPCC engineering elements required in an IPCC study, their application to the Moatize project, and the drivers which most impact the viability of IPCC at Moatize.

Aug 1, 2013

By G. R. Guillet

Salt is restricted to five major beds in south western Ontario, totalling as much as 200 m in thickness. These beds are located at depths ranging from 270 m to 750 m below the surface, fringing Lake Huron and the Detroit River from Windsor to Kincardine, and extending inland as far as London. Manitoulin Island, the Bruce Peninsula and the north part of the Niagara Escarpment form the northeastern rim of the Michigan Basin, a major structural depression in which the salt was deposited 400 million years ago when much of North America was covered by the Silurian sea. Salt is mined underground at Windsor and Goderich; it is also brought to surface as brine through deep wells at Windsor, Samia and Goderich. Artificially- created caverns in salt beds are extensively used for storage of liquid hydrocarbons at Windsor and Samia.

Jan 1, 1984

By A. A. Bakke

"The Fort Knox gold deposit is hosted within the Fort Knox Pluton, a Cretaceous multiphase granitic body that intrudes the Fairbanks schist. Gold occurs along the margins of stockwork veins and veinlets, quartz-filled shear zones, and along fractures within the granite. The mineralization is generally sulphide-poor and closely associated with trace amounts of bismuth, tellurium and to a lesser extent with molybdenum and tungsten. At present, proven/probable reserve estimates, based on a cutoff grade of 0.39 g/t Au, are 158.3 million tonnes grading 0.83 g/t Au.The Fairbanks schist comprises the bulk of the country rock. The dominant lithologies present include muscovite-quartz schist and micaceous quartzite. Immediately north and south of the main orebody, mixed metamorphic lithologies of the Cleary sequence, a subunit of the Fairbanks schist, have been mapped. Development of local zones of weakness, most likely due to a broad regional warping event, resulted in brittle-ductile deformation and activation of a northwest-southeast shear couple between contrasting lithologies.The Fort Knox Pluton consists of at least three phases based primarily on textural differences. Intrusion of a fine-grained granite was followed by a medium-grained porphyritic granite. The youngest intrusive phase is a coarse-grained, seriate porphyritic granite, the Vogt Stock. The Vogt Stock forms an elongate dome with the axis in the east-west direction. Structures displayed in the overlying units, believed to be the result of doming, include tension fiSSUres and longitudinal fractures.Premineralization fractures, the result of the magmatic doming, provided conduits for initial stockwork quartz vein development and quartz enrichment in shear zones. Weak development of vein-controlled phyl/ic, potassic, albitic, and argillic alteration styles are present. Evidence of a late thermal event resulting in a low-temperature alteration assemblage of calcite + zeolite (stilbite) + chalcedony + clay occupies breccia zones, joint surfaces, and fractures within the granite."

Jan 1, 1995

By J. A. Russell

MR. M. W. Boom: I would like to congratulate Mr. Russell on his fine paper. One very good point which has always appealed to me is the smooth working of a steam hoist as compared with electrical. He does not mention the steam hoist at Springhill which has been working there for a good many years. MR. S. R. NEWTON: I have read with a great deal of interest the paper presented by Mr. Russell on the development of haulage engines in the mines of the Dominion Steel & Coal Corporation. He is to be congratulated on having produced a comprehensive article showing, step by step, the various improvements that have been made over the years in the design of such engines. I am quite in accord with Mr. Russell's statement that the positive tooth clutch can have too many teeth, and also that the method of driving a sliding clutch hub of any design should be by means of a hexagon or octagon on the shaft. Where the clutch hub does not of necessity slide on the shaft it can be pressed on and keyed to the shaft in the normal manner. With regard to the 'Cramp' internal-expanding jaw-type clutch, while it is true there are more moving parts than with the clutch consisting of a ring with internal cut teeth and a driver having a fewer number of teeth as .described by Mr. Russell; there are compensating advantages to the internal expanding jaw-type of clutch. The V shaped profile of the teeth permits of engagement of the clutch with very much less 'jockeying' of the drum. This is particularly the case in vertical-lift mine hoists, where it may be necessary to engage and disengage the clutching mechanism at frequent intervals.

Jan 1, 1944

By J. A. H. Church

MR. J. A. H. CHURCH: The salient feature would seem to be that the thickness of the seam, in our coals at any rate, is the main factor in predisposition to spontaneous ignition. The evidence, incomplete it must be admitted, in the Saskatchewan and British Columbia fields, and complete in the Alberta field to my mind, shows this up very strongly. The German report on the upper Silesian coal fields definitely fixes the critical thickness at 13 feet, the British report goes far beyond this figure by stating that liability to ignition increases with the thickness of the seam over four feet. Before discussing the Alberta fires it would be well to note an error on page 12 -the probable cause of the fire in the Frank Mine should read "Spontaneous near fault. Heating first discovered 1909". Of the six fires attributed to spontaneous ignition all the seams were identical or in excess of the critical thickness mentioned in the German report. If there be any reason in the foregoing it is high time some forethought were taken to adopt some definite system of laying out the workings of such seams not so much on the outcrop districts as with a view to the future operation to the dip. Seams approaching 13 feet in thickness which to date have shown no disposition towards heating during the extraction of the outcrop areas may well cause infinite trouble or indeed total loss when the ventilating pressures increase as increase they must to the dip. This state of affairs can be combatted only by the adoption of a correct system of working and the provision of numerous airways of as large an area as may be compatible with the physical characteristics of the particular seam.

Jan 1, 1923

By P. J. Deveaux, M. J. Kreczmer

The Tartan Lake deposit 12 km northeast of Flin Flon, Manitoba, was discovered in March of 1984 during the investigation of a VLF anomaly. The discovery hole intersected 16.83 metres averaging 21 gm Au/tonne. Since then, 99 holes, over 21,000 metres, have been drilled outlining 419,491 tonnes grading 11.79 gm Au/tonne in a di stinct group of mineralized lenses referred to as the Main Zone. Three other mineralized zones are known on the property but no reserves have been allowed for these, the South , East and Base Line zones. The Main Zone consists of seven parallel, east-west striking, quartz lenses. The lenses dip steeply to the north and plunge steeply west to northwest. Lens number l strikes for 160m and extends vertically to the 90m level. Within th is lens there is a 60m interval of low grade materi al. Lens number 2 is located about 5-l0m within the foo twall of Lens number I. Near surface this lens stri kes for 40m, at 200m level the strike length increases to 200 m. To date the deepest mineralization on Lens 2 has been intersected at a vert ical depth of 527m. Five smaller lenses are located in the foo twall of Lens 2 , containing gold va lues similar to the two main lenses but erratically distributed. The South Zone, located 100m south of the Main Zone, strikes east-west fo r l00m above the 100m level. The East Zone, found 230m east of the Main Zone, strikes fo r 80m and may possibly be an ex tension of the South Zone. The Base Line Zone is located 275m south of the Main Zone. Sporadic, but very significant gold intersections have been obta ined1n all three zones. Gold-bearing quartz-ca rbonate tourmaline veins are generally confined to a silicous crystal tu ff hori zon. The crystal tuff exhi bits fi ve distinct types of alteration: silicification, sericitization, ca rbonati zation, chlorit ization and pyritization. Silicification has resulted in a perasive addition of silica and the generation of multiple quartz veins. Sericiti zation is restricted to the crystal tuff. All rock units are pervasively carbonatized . Ankerite is abundant in the quartz veins and within the shear zones, particul arly those located along the chilled margin of a nearby gabbro-diorite intrusion. Chloritization is widely spread th roughout the rock units, while pyritization fo rms a broad alteration halo associated with the orebody. Sulphide accesso ry minerals associated with the gold , whi ch fo r the most part appears to be free, are chalcopyrite and pyrite. Generally, the higher grade gold values are related to an increased content of sulphides in the qua rtz veins. The average sulphide content in the deposit is less than 5 %.

Jan 1, 1986

By George B. Saunders

The mines in western Canada producing steam coal will find a better opportunity this year to market their product in Winnipeg - for two reasons: First, the new wage schedules, signed with local unions at each mine, have enabled them to reduce the selling price materially. Second, the duty on slack coal coming in from the United States has been raised to 50 cents, which is equal to the duty on run-of-mine coal. This has had the effect of raising the cost of mine-run to .the importer. Formerly, it was the practice to bring in slack coal under a duty of 14 cents and lump coal under a 53-cent duty and, by judicious mixing of the two, manufacture a mine-run coal at an average duty cost of about 22 cents. Fortunately, through efforts of the Alberta Government, and other friends of the Canadian coal trade, the Federal Government was persuaded to adjust the duty on slack coal as indicated. While it will be found that the Manitoba market, this season, is slightly more easy of access we have still a long way to go before we reach the desired goal. Geographically and economically the Manitoba market should belong to western Canada. However, it has been found a very profitable market for United States mines because large tonnages of coal can be shipped, practically at the convenience of the mines, via the Great Lakes, during seasons of slack business. They will therefore not relinquish this market without a struggle.

Jan 1, 1925

By D. L. Johnston

"Function and ApplicationsWater-only cyclones, (WOC) are a dynamic mineral separator which cause minerals to separate in a water medium by virtue of difference in specific gravity. Figure 1 shows diagramatic plan and sectional views of a water-only cyclone.A slurry of mineral matter and water is fed through the inlet opening under gravitational or pump pressure. The combined effect of centrifugal action and conical shape is to concentrate the heaviest fraction of mineral on the periphery and bottom of the cyclone. This layer of higher specific gravity particles increases in thickness and density between the cyclone inlet and apex. The action in the bed of higher gravity particles formed in the flattened portion of the cone surrounding the tip of the vortex finder deter;nines the specific gravity of separation or cut-point. Mineral particles of lower specific gravity flow with the bulk of the water, out the vortex finder. Mineral particles of higher specific gravity flow with little water out the apex. A more technically e:mct description of the functioning of the water-only cyclone can be found in previous publications noted in the references.The water-only cyclone was invented and refined by J. Vis man, formerly of the Canadian Mines Branch staff, between 1958 and 1965. The first industrial application noted in the literature was when it was introduced as a cleaner for fine coal in 1962. Since 1970 the water-only cyclone has become a common separation apparatus in many Canadian and foreign coal processing plants. The only other mineral industry application known to the author is in separation of gold bearing heavy minerals from sand<'>. The potential does exist for other applications and this area deserves to be investigated more thoroughly than it has been."

Jan 1, 1989

By Thomas E. Shumka

ASTM E2905 describes a two-part standard for electromagnetic methods for preparation and examination of ring gear teeth in the mining sector for SAG and Ball Mill ring gear drives, including pinions? particularly on the addendum, dedendum, and root areas. This practice addresses the need to detect surface breaking flaws electronically and to have the ability to accurately size any surface breaking cracks found on cast and forged SAG and ball mill ring gear and pinion teeth faster and more effectively than other methods. Eddy-current surface arrays are seeing increasing use throughout the industry for the detection of surface breaking flaws in conducting materials. Example applications include examinations of pipelines, bridges, engines, aerospace structures, and any conducting material for surface breaking flaws including cracks. In addition, model-based methods are being used to size cracks accurately found in the addendum, dedendum, and the root of SAG and ball mill girth gear teeth. As visual interpretation of a surface breaking discontinuity on gear teeth is the normal analysis, the colors and 3D images that are provided with this technique, help with visualization and therefore are absolutely invaluable in such circumstances. This practice will help to standardize the use of this nondestructive testing approach.

May 1, 2013