Search Documents

By Peter Lighthall

What is an engineering firm?s role? ? The ideal situation is a life of mine service alliance with the owner ? Engineering firms are long term custodians of information ? Maintain consistency with established closure objectives, adjust closure plans to meet changing situations and technologies ? Develop range of solutions and present owners with risk profile The mine closure planning process ?new mines ? For metal mining, geochemistry is the issue ? The planning process: ?Sampling ?Waste characterization ?ARD prediction ?ARD control strategies ?Life of mine waste management planning ?Assessment of residual impacts ?Development of strategies for dealing with residual impacts ?Estimate closure costs ?One time decommissioning and reclamation costs ?Ongoing treatment/maintenance costs

May 1, 2006

By R. Tipman

"In 25 years, processing of tar sand progressed from two small pilot plants to two major commercial operations owned by Syncrude and Suncor. These plants mine tar sand and extract the bitumen which is then converted into a synthetic crude oil. Considerable research on extraction of bitumen from tar sand has been undertaken by these two companies as well as other major oil producing companies, private individuals, universities and the federal and provincial governments. These studies have produced a number of alternate processing schemes which have yet to be commercialized. The producing companies are focusing their efforts on achieving increased processing efficiency, which includes improved bitumen recovery, reduced unit cost, energy conservation, and equipment reliability. In this review, the Syncrude process and examples of new process developments will be briefly described. IntroductionTwenty-five years ago, tar sand processing was limited to two pilot plants owned by Cities Service Athabasca Ltd., and Great Canadian Oil Sands. Earnest Manning was Premier of Alberta and was inviting proposals for the construction of a commercial tar sands plant. The invitations called for a much larger operation than those which had been undertaken in the past. All of the previous attempts at commercial operations up to 1960's had failed, largely because of a poor technical understanding of the process requirements, lack of suitable equipment, and lack of adequate capital. The previous record was not good. The pending new large scale plant was based on improved but not proven technology and equipment, which were developed from the pilot plant studies. In addition, the surplus of conventional oil in Alberta and low world oil prices were factors reducing the need for such a plant."

Jan 1, 1987

By Esteban M. Domic

"T.L. Leaching ProcessCommercial PerformanceSociedad Minera Pudahuel Ltda. (SMP) has been innovating in the copper producing field with the commercial application of the Thin Layer (T .L.) leaching process in its two operating division s: Lo Aguirre and La Cascada. Since November 1980, SMP' s Lo Aguirre Division has been producing high-purity copper cathodes at a nominal rate of about 16,500 metric tonnes / year, by mean s of the new route of T.L. leaching, followed by solvent extraction and electrowinning (TLlSX/EW). This has been the first commercial application on T .L. technology in the world, and the only commercial application in Chile for solvent extraction and electrowinning.By mid -1980, SMP acquired Sagasca Mining Co., renaming it as La Cascad a Division. The existing vat leaching facilities were modified to apply T.L. in the same old vats. The existing scrap iron cementation recovery circuit was kept running for the continuing production of copper precipitates. The modifications in the leaching circuit allowed shorter treatment cycles with a lower acid consumption and consequently, copper product ion increased from a previous historical high of 12,000-13,000 metric tonnes /year to a new level of about 22,000 metric tonnes/ year . These changes have been in operation since March 1981.T.L. Leaching commercial performance, both at Lo Aguirre (TL / SX /EW) and at La Cascada (TL/cementation), has been presented in several recent publications. Real operating parameters and process requirement s were reviewed in detail. A breakdown for TL / SX/ EW economics was also published based on Lo Aguirre' s performance during 1982(41."

Jan 1, 1986

By M. A. Vos

"Cretaceous sands and clays underlie an area of approximately 5,000 km2 in Northern Ontario, southwest of James Bay. The deltaic deposits occur as a wedge of continental sediments to the north of an east-trending fault scarp referred to as the Precambrian Escarpment. They rest on older sedimentary formations of the Moose River Basin (Jurassic, Devonian) and are covered by glacial tills and marine sediments of the Quaternary period. Outcrops are restricted to occasional exposure in the deeply incised riverbeds.In 1975 and 1978, drill programs sponsored by the Ontario Government provided new information on the extent and quality of the deposits. Fourteen holes at approximately 12-km intervals were drilled to a maximum depth of 189 m by reversed- circulation chip drill methods. Some core was obtained as well. Analytical results show that the thickness of Cretaceous deposits exceeds 100m in several instances. Abundant kaolinitic clay and quartz sand of glass-grade quality, both unique materials in Ontario, are available in an area where hydroelectricity and lignite resources combine to enhance the energy outlook.IntroductionThe presence of refractory clay in deeply incised riverbeds in Northern Ontario was known to geologists travelling the rivers as early as 1875. Robert Bell (1877) reports outcrops of clay and lignite on Coal Brook, a tributary of the Missinaibi River. E.B. Borron in 1880 collected a sample of clay from the bed of the Missinaibi River which H.H. Croft of the University of Toronto considered to be ""nearly if not quite, equal to the Cornish clay used in the manufacture of English porcelain"" (Keele, 1920, p. 42). The Cretaceous age of the clay, sand and lignite deposits was determined with the help of plant remains collected by Keele. He referred to the deposits as the Mattagami series, which later became the Mattagami Formation."

Jan 1, 1982

By David J. T. Carson

"The metalliferous deposits of Vancouver Island have generally been assigned to the Mesozoic ""Coast Range Orogeny."" However, a metallogenic study by the writer has revealed that several important classes are early or middle Tertiary. Included are porphyry coppers, and gold-quartz, arsenic and copper-arsenic veins.The porphyry coppers and many gold-quartz veins are within and adjacent to Oligocene-Eocene quartz diorite intrusive complexes. Arsenic and copper-arsenic veins have a close spatial relationship to sills and laccoliths of Oligocene dacite porphyry which intrude the late Cretaceous Nanaimo Group.Other deposits of demonstrable Tertiary age include a molybdenum stockwork related to a relatively potassic Eocene plug and a few small copper-skarn occurrences. Some copper stockworks and a mercury deposit are probably also Tertiary.The copper deposits of previously recognized Tertiary age are those of the Sooke area that occur in Eocene basalts and Oligocene gabbros."

Jan 1, 1969

By Theo Mayer

Presentation Outline Define data visualization in the context of workflow Present other industries? application and demonstrated benefits Provide conceptual tools to help you address a visualization strategy Hold 10,000 foot view ? to touch on many issues

May 1, 2008

By A. Brown

THIS P APER has been pre-pared as a progress report on Mines Branch investigations into problems of ground stress in certain co al mines of Western Canada. As such, it should be considered as a companion report to the one ( 1) presented to the Mining Society of Nova Scotia in 1956 and which dealt with similar investigations in the coal mines of Eastern Canada. For the past 50 years, dynamic incidents in the form of 'bumps' and 'outbursts' have been occurring in the coal mines of the Inner Foot-hills belt of tl1e Canadian Cordillera. As these phenomena generally become more frequent with in-creased thickness of overburden, a limiting depth of mining of 2,500 feet has been set (2) for estimating recoverable reserves of coal. If such a view were accepted, from a long-term viewpoint very large resources of coking-grade ?coal -in a part of the continent deficient in such coals -would not be available to the nation. The terrain in which these in-6dents take place may be described in geological terms as being dominated by pronounced structure in strata ?consisting of a large proportion of highly indurated rocks. The Geological Survey of Canada has co-operated by carrying out structural studies (3) at the mines, supplemented lithological by stratigraphic observations.

Jan 1, 1958

By T. Takahashi, K. Oyamada, Y. Miyata, T. Isoo

The carbonation reaction of steelmaking slag has been known for many years. However, the size of blocks manufactured from this by-product material has been limited due to the difficulty of achieving a uniform reaction throughout the block. Using newly developed conditions, large porous slag blocks (1.0 x 1.0 x 0.5 m) were produced by car¬bonation of steelmaking slag with the optimum amount of water and supplying CO2 deep into slag powder compacted in molds. The development of these blocks has great poten-tial to solve the problem of slag utilization, for example, by recycling slag in large car¬bonated blocks for artificial fish reefs and seaweed cultivation beds. This paper de¬scribes the carbonation reaction, the new process for producing large slag blocks, and the utilization of blocks in past and recent years.

Jan 1, 2004

By Desmond M. Connor

"The State of the EnvironmentRecent data from a State of the Environment report prepared in January 1991 and released in April (see references) , indicates that the physical and biological environment across Canada is deteriorating in some important ways. For example: • emissions and atmospheric levels of CO2 are rising at a rate more than 50% of the U.S. increase; global temperature continues to rise, especially during the last decade;• while S02 emissions have been falling since 1984, NOz has declined only slightly since that time; N02 in Canada rose 43% during 1970-87, compared with a 7% rise in the U.S.;• municipal discharges of phosphorus and BOD (biochemical oxygen demand) to fresh water have been rising steadily since 1983);• pulp and paper mill discharges to fresh and Pacific coastal waters have been rising, 1970-87;• migratory game bird populations (Prairie Mallard, Northern Pintail) have been declining for the last 20 years;• total per capita energy use continues to climb.The State of the PublicSimilarly, data from recent public opinion surveys shows that public concerns about the environment are either rising, or are remaining at a high level despite the competing claims of the economy and political events for attention.For example, Professor Reginald Bibby's national survey this year shows that Canadians rank our top three issues as theeconomy, the environment and government incompetence.An Angus Reid survey commissioned by the Mining Association of Canada and other mining organizations in 1989 showsthat, despite general support for its economic benefits:• 67% of the general public perceive the mining industry to be a major source of pollution and environmental contamination;• 68% believe that a new mine should not be developed if it will disturb local wildlife;• 52% would prohibit a new mine if it required a road through a national park;• 49% would disallow mine development if it took as much land as an average farm in an agricultural area or if it limited sports fishing in a local lake."

Jan 1, 1991

By J. Fox, K. Kocsis

"Planning for sustainable cooling potential requires protected space to successfully maintain chilled propylene glycol in storage until needed. Stored propylene glycol should be judiciously cared for, safely kept from the ill effects of heat, in order to remain useful for bulk air cooling. Minimizing the chilled temperature of the propylene glycol reservoir tanks means that atmospheric conditions will be monitored closely during the chilling phase. Storage facilities would maintain restricted airflow while minimizing possibilities for heat transfer during the storage phase. Sustainable cooling systems could reduce or eliminate the need for mechanical cooling if installed with favorable conditions. Storing the cooling potential from the winter months is what this new design is all about.INTRODUCTIONIn most subsurface, bulk air-cooling methods, the main source of potential cooling energy comes from cold-water applications. This paper investigates the practical use of harvested, chilled propylene glycol as the source of cooling potential. Propylene glycol is chosen as the cooling storage liquid refrigerant since its chemical make-up is intrinsically safe to fresh water supplies and will not harm underground workers should a leak occur in the closed cooling circuit. Harvesting the cold of winter is a meaningless endeavor without proper thermal planning for the storage of the cooling potential in cold refrigerant.PROPYLENE GLYCOL STORAGE RESERVOIRA new design for a closed refrigerant bulk air cooling system employing propylene glycol as the refrigerant is presented as the main design topic of this paper. Given that a deep and hot mine will need to be considered safe and productive, a cost-effective cooling system is desired in order for the mining operation to be considered sustainable. For underground mines at northern latitudes, cooling applied to fresh air is only required 3 to 4 months of the year. During winter, ambient atmospheric conditions can be harnessed and stored for use at a later time.The basis of this sustainable design uses very cold ambient air that is circulated around galvanized steel refrigerant reservoir tanks. The propylene glycol reservoir tanks are arranged in a concrete walled pit, or tank farm, excavated in bedrock. During the coldest months, the tank farm will be exposed to the open air. As the seasons change the tank farm will be covered with insulation to maintain the maximum cooling potential for use during the warmest months of the year."

Jan 1, 2019

By F. Liu, S. Rezaei, M. Muinonen, M. Barati, V. L. Lakshmanan, S. Marcuson

Canadian nickel-copper ore deposits have been a major source of nickel, copper, cobalt and precious metals for more than 100 years. The two main minerals of interest, pentlandite (Pn, (Ni,Fe)9S8) and chalcopyrite (Cp, CuFeS2), are usually accompanied by large quantities of pyrrhotite (Po, Fe1-xS). Until the 1950s, Po containing small amounts of nickel was routinely smelted as part of the valuable Ni concentrate. The rapid growth in Ni demand following the Second World War created impetus to treat the Po separately. This action would liberate a valuable smelting capacity for higher value Pn, allow for recovery of Ni locked in Po, convert the Fe to iron oxide or metallic iron pellets, and recover S as sulphuric acid or elemental sulphur. The roasting process also has the potential to produce energy due to the highly exothermic oxidation of Po. The Ni industry would then have a “waste-free” process. Both Inco (now Vale) and Falconbridge (now Glencore) developed processes and built large industrial plants for this purpose that operated with some success. But technical issues and tenuous economics were continual challenges. By the early 1980s these industrial operations were closed. Sophisticated froth flotation methods of rejecting Po were developed, and Po containing up to 1% Ni became a waste material reporting to the tailings stream. As part of a major study on possible processing methods of Po for both value recovery and waste remediation, this paper presents a historical perspective on Canadian Po tailings with regards to their generation, inventory, value, and attempts to process them.

Jan 1, 2017

By R. W. Thompkins

The two largest contributors to silicosis in machine men are dust from drilling and dust from blasting. With the advent of the shatter-cut method of blasting, the evils of blasting dust were greatly reduced. The problem of dust from drilling has been attacked from two different angles: (1) The adoption of dustless frontheads or enlarged water tubes, both of which have proved capable of reducing dust concentrations; and (2) The adoption of better ventilation. Many operators are loath to adopt dustless frontheads or enlarged water tubes on Leyner drills because of the increased repair costs on drills, and also because it has been found difficult to enforce 'the proper usage of dustless machines: for example, workmen sometimes plug the vents in the fronthead.

Jan 1, 1943

By H. B. Lumsden

This paper is intended to deal merely with the commercial development of some of the principal non-metallic mineral resources in the three prairie provinces- Manitoba, Saskatchewan, and Alberta. Coal is not included in this summary. Building Stone First and foremost, mention may be made of the building stone now being produced at Tyndall, Manitoba. This is a mottled limestone and is declared by experts to be one of the finest building stones in America, both as regards durability and appearance. It has been used very extensively both for exterior and interior work, not only in western Canada, but also in the principal cities as far east as Montreal. The stone is the "'Upper Mottled Limestone", which forms the summit of the Trenton (Ordovician) strata in the Lake Winnipeg basin. Quarries are at present being operated at Garson and Tyndall . The area where this stone is known to be available extends in a north and south direction for a distance of three miles, and the main productive ridge is probably about one half mile wide. The outlook for the future of the industry is extremely promising, as the stone is becoming increasingly popular in Eastern Canada, more particularly for interior work.

Jan 1, 1928

By E. Y. Carlson

"IN A SHORT PAPER it is impossible to do much more than to list the industrial minerals found in Saskatchewan and to give a brief description of the activity associated with each. I will not attempt to discuss the geology. It is sufficient to say that the settled part of the Province is covered by glacial drift which varies in thickness from a few feet to several hundreds of feet, and that this has hindered the search over much of the Province.CLAYA notable exception to this is the Cypress Hills area in the southwest corner which did not suffer any glacial action and where we find some of the large exposures of Cretaceous clays. In this area, the majority of the deposits are of stone-ware clays which are •an excellent raw material for such products as face brick and sewer pipe. Although the clay cannot be transported over any great distance it is used extensively in Alberta and Saskatchewan in the production of these products."

Jan 1, 1959

By M. G. Mena, M. S. Mena-Junio

Silver (Ag) filler is the most attractive choice among all the conductive fillers of die attach materials for the attachment of silicon devices because of its balanced properties and relatively low cost. However, a major problem of silver is that it electrochemically migrates in the presence of moisture and applied bias. In microelectronic devices, silver migration can occur between adjacent conductors/electrodes, which leads to the formation of dendrites and eventually results in short-circuit failure. In order to assess the reliability of these conductive fillers, an investigation for two types of Agfilled die attach materials was done using the water drop test at room temperature and using a 1000 hour temperature-humidity-bias (THB) test under 85 ºC and 85% RH conditions. Four different bias/voltages and six different electrode distance spacing were used. Both dendrite and cloud/lace-like growths were observed as a result of the electrochemical migration of silver, Water drop test results revealed that increasing the applied bias/voltage and decreasing electrode spacing causes migration to occur faster, thus resulting into shorter time to fail (TTF). It was also observed that the growth rate of the dendrites from the cathode increased linearly as the dendrite approached the anode, probably due to a combination of increased ion availability and electric field. A minimum applied bias of 3 volts was required for migration to occur in Epoxy A as compared to 2 volts for Epoxy C. The higher migration voltage requirement for Epoxy A was attributed to the higher volume resistivity of the said epoxy. In addition to the minimum voltage requirement, it was observed that a minimum electric field of about 1 volt/mm is required for migration to occur. The 1000 hour THB testing did not result into any failures. It is surmised that the presence of condensed moisture is another requirement for migration. Such condition is not present during the THB testing.

Jan 1, 2012

By H. W. Wevers

This paper is the result of an intensive literature search and practical study of the problems experienced by a mining company with the frame cracking of their large-tonnage haulage trucks. It explains the advantages of particular HSLA steels for applications in the welded structures of such equipment. Examples of existing welds in truck frames are analyzed. Modern fatigue models and linear elastic fracture mechanics techniques are explained.

Jan 1, 1978

By S. G. Luckey, N. R. Harrison, F. Nadeau, U. Brüx

"The adoption of tailored-rolled or tailor-welded blanks (i.e. TRB/TWB) in the automotive industry has been known to offer great potential for the optimization of weight, function, cost and complexity. Vehicle light weighting can further be achieved by using high strength aluminum alloys like the 7xxx-series. 7xxx-series alloys are capable of delivering specific strengths equal to or greater than high strength steels. However, room temperature formability of this aluminum class is limited, so one approach to forming 7xxx-series alloys is by hot stamping. Hot stamping utilizes an elevated temperature blank and the high pressure stamping contact of the forming die to simultaneously quench and form the sheet. This paper explores the initial feasibility of tailored thickness material for body-in-white applications when processed under hot stamping conditions.INTRODUCTION Steel tailor-rolled blanks (TRB) or tailor-welded blanks (TWB) have been used within the automotive industry as a method of reducing weight, expanding material utilization, and decreasing overall part/assembly cost (Ganeasan et al., 2015; Merklein et al., 2014; Hirt et al., 2005; Kridli et al., 2000). The production of such tailored thickness materials has resulted in over $2.5 billion (2016) in combined industry sales (Mubea, 2018). As automakers begin to adopt the manufacturing practices traditionally reserved for steel such as tailor rolling/welding with greater enthusiasm for vehicle light weighting, there exist an opportunity to expand the material database to extend beyond the traditional aluminum alloys found in current production. High strength aluminum alloys, i.e. 7xxx-series, are ideal for structural automotive applications due to their high specific strength; however, they have limited room temperature formability. Hot stamping, another manufacturing practice used by the steel industry, can be used to form these high strength materials. The combination of tailoring the thickness of a sheet material and hot stamping provides an opportunity for significant weight saving within an existing manufacturing footprint. This paper explores the potential and challenges of this approach when applied to structural body-in-white components. The methods for tailor rolling, tailor welding and hot stamping are described and applied to the production of a 7075 aluminum alloy B-pillar. The results are discussed in terms of feasibility and weight savings."

Jan 1, 2018

By C. S. Chen, Y. J. Luo, M. W. Gao, B. Li, Z. F. Zhang

"To obtain large-sized billets with fine grains and homogeneous elements distribution, uniform direct chill (UDC) casting process, based on annular electromagnetic stirring coupling with intercooling, was employed to produce 7055 alloy billets with a size of F584 mm in this study. The results indicated that there were the coupled effects of annular electromagnetic stirring and intercooling on grain refinement and element homogenization, and also the billets produced by the UDC casting process showed excellent hot workability in comparison to the normal direct chill casting process.INTRODUCTION The high solute 7055 aluminium alloy has a wonderful combination of high specific strength and hardness, good resistance to stress corrosion cracking and high fracture toughness, which is very useful in aerospace application (Yan et al., 2013; Mondal & Mukhopadhyay, 2005). The production of large-sized 7055 alloy billets with high quality is the basic condition for the subsequent application of 7055 alloy to the aircraft. Inhomogeneous microstructures and performances of 7055 billets result from the high alloying element content and the inhomogeneous cooling condition in different regions of billets during the conventional direct chill casting (Paramatmuni et al., 2004; Lalpoor et al., 2011), which will bring bad influence to processing property, functional performance and utilization rate of materials. To alleviate segregation and obtain fine and uniform grains, some effective treatment methods were proposed including electromagnetic stirring (EMS) (Vives, 1989), ultrasonic vibrating (Zhang et al., 2011) and melt conditioning (Fan et al., 2013), on the melt to obtain fine and uniform grains. However, these methods could not effectively decrease the large temperature difference between central and periphery parts of the billet, because the solidification mainly depends on outside cooling including mould cooling and water spraying cooling. To change the heat extraction pattern of the billet functioned solely from the outer surface, based on annular electromagnetic stirring (A-EMS) invented by Xu et al. (2010), Luo et al. (2017) proposed uniform direct chill (UDC) casting coupling A-EMS with intercooling in the direct chill (DC) casting process. An in-mold cooler was inserted to the melt sump, and thus the alloy melt temperature and concentration at solidification front become more uniform."

Jan 1, 2018

By John E. Udd

I N Part I of this paper, Professor Morrison suggested that our technique of causing cracks to develop around openings in a sheet of photoe1ashc plastic is, in effect, a laboratory-scale rockburst. Our investigations have indicated that the location and direction of these cracks are predictable, and that their growth can be controlled. On several occasions, we have been able to cause these cracks to propagate sufficiently slowly to be followed, with the naked eye. In practice, the rate of growth, gradual or sudden, would depend upon rock properties. This part of the paper presents an analysis of the stresses surrounding the openings before and after failure and also this author's views on the causes and after-effects of cracking. An attempt is made to correlate the stress patterns with those deter-mined from pure mathematics. Considering that the openings, except for the central enlargement, are long apertures with somewhat rounded corners, they might be compared with elongated ellipses having axes ratios of about 20:1 or with

Jan 1, 1963

By Frederick J. Browne

Water, water everywhere, but not a drop (fit) to drink! Trite, but how often only too true? What is there met with in mining which, under various circumstances, may be said to be the most sought-for and highly-prized and also the most objectionable and most feared? Water! What visions that combination of five letters brings to all thoughtful minds? Up to near the end of the eighteenth century water was thought lo be an element but was then discovered to be the result of the combustion of two volumes of hydrogen with one volume of oxygen, and water so produced is chemically pure. Pure water is a clear and colourless liquid when seen under ordinary conditions, but appears bluish when seen through a long tube, and this same bluish tint may be observed in many lakes, especially those of glacial origin. A story often told describes a prospector in the desert who, failing to find water to replenish his canteen, suffers torture and death under fearful circumstances. Then again we may recall the flooding of mines, where water poured in so quickly that there was no opportunity of saving the unfortunate workmen. Instances might be multiplied without number showing that either the lack or excess of this essential fluid has taken heavy toll of human life. In all branches of mining and associated industries water must be dealt with to a larger extent, from an economic point of view, than any other substance, and very often the purity of the water is a matter of considerable importance.

Jan 1, 1925