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By Laurier Juteau

"NOT TOO LONG AGO, the CIM Education Committee saw the need for an information campaign to promote interest in mineral industry careers among young people. Today, times have changed and the Committee has now placed emphasis on the definition and function of the mining engineer. This situation, we believe, is entirely normal and the change of emphasis is not due to a change in the needs of the industry but more to a diversification of these needs. In years past, the Canadian mineral industry, although a very important part of our economy, was looked upon as a specialized craft and, because of the richness of our resources, did not suffer too much from competition. Now, times have changed and we are increasingly at the mercy of the competition and damaging inroads of price fluctuations, etc. We will therefore answer the questions raised in this discussion in the light of the role played in the past and the role to be played in the future by the Canadian mining engineer. We will begin with the following premises : (a) If mining engineers are to be involved in the massive problems of society, their traditional background is not sufficient. (b) Councils for professional development are working on criteria for the accreditation of advanced degree programs in the United States as well as in Canada, and, simultaneously, three-year technology programs are being developed along with professional engineering degree programs. (c) The difference between European and American industries regarding philosophy of life is that in Europe they appreciate wisdom more than HPs while in America the HP seems to be more important. The Engineering Digest of February 1972 reported that in the United States, during June and July of 1971, the second highest rate of unemployment was for the 55 to 64 age group ( 4.1 per cent). This survey certainly applies to Canadian industry as well. (d) Degrees to be awarded in Canadian universities and technical schools in 1972 will be:"

Jan 1, 1972

By J. A. Hillier

"IntroductionThe purpose of sampling is to remove a portion of material from a stream which is representative of it in size, moisture and mineral content.To prevent the effects of segregation, generally caused by the way in which a conveyor, pipe or launder is loaded or directed, the sampler should cut proportionally the entire cross section of the stream.If one conveyor transfers to another at a right angle, fines may be dropped on the near side, and the coarse material thrown to the opposite side. Segregation can also occur as a result of the motion of a conveyor belt passing over the idlers causing the coarse material to roll to the sides of the belt.When slurry changes direction of flow in a launder or pipe, the heavier and coarser fraction will centrifuge to the outside of the curve and tend to remain on one side of the stream. Similarly, if two streams joining in a common launder are not mixed at the point of confluence, they will continue down the launder unmixed . This effect is particularly noticeable in a plastic lined launder.Therefore, a proportional sample is usually accomplished by a constant rate of cutter travel across the entire stream, making certain that the cutter is not full or splashing over before reaching the end of travel.The cutter should operate on a constant interval based on time, tonnage and uniformity of flow. The opening should be at least three times the width of the largest piece to be sampled. The cutter width is more critical with ore samples where particle sizes are large. With slurry samples, the opening is usually much larger than the minimum in order to obtain sufficient samples"

Jan 1, 1989

By C. T. Wiliams, John B. Bush, John Lamb

"THE TOWN OF HEDLEY is in the valley of the Similkameen River, about 200 miles east of Vancouver and 25 miles north of the International Boundary between British Columbia and the State of Washington. The main ore deposits are located on Nickel Plate Mountain, northeast of the town.The outcrop of the Nickel Plate system of orebodies is at an elevation of 5,900 feet. It was discovered in 1898 by prospectors and sold in the following year to the Marcus Daly interests of Butte, Montana. Production commenced in 1904 under the name of Daly Reduction Company. In 1909 control passed into the hands of the Hedley Gold Mining Company. Operation of the mine continued until 1930, when exhaustion of known ore reserves forced it to close. Upon the recommendation of Paul Billingsley (3) the mine was optioned by the 1. W. Mercer Exploration Company in 1932. Production began once more in 1934 under the name of Kelowna Exploration Company Limited, and was practically continuous until August 1955, when the mine was again shut down. The name of the latter company was changed in 1951 to Kelowna Mines Hedley Limited.The Mascot Fraction, a small wedge-shaped claim lying astride the Nickel Plate orebodies, was mined by Hedley Mascot Gold Mines Limited between 1935 and 1949. The geological setting and structural control of ore are essentially the same as in the adjoining Nickel Plate Mine.Total production from all operations on Nickel Plate Mountain to the end of 1954 was approximately 3,800,000 tons of gold ore, with a gross value in excess of $48,000,000.General GeologyNickel Plate Mountain occupies the gentle westerly dipping limb of an asymmetrical anticline, the axis of which trends northeasterly. The rocks are composed of a thick pile of Triassic limestone, limy argillite, and quartzite, -resting on a flattish floor of granodiorite near the base of the mountain. Associated with these sediments is a host of porphyritic sills and dykes of gabbro-diorite composition. In the mine area east-west brown soda-rhyolite dykes and north-south black andesite dykes crosscut all the other formations and the ore, probably following steep later fractures."

Jan 1, 1949

By Anthony P. Makuch

Dynatec Corporation is an integrated mining services company, providing mine development, operations management, engineering, drilling and metallurgical services to the North American mining industry. Dynatec was the contract operator of the Ken Snyder Mine in Midas, Nevada from start of production in January 1999 to September 2001. This paper summarizes Dynatec?s experience and approach to the use of longhole stoping methods for mining to widths of 1.3 to 2 metres in a steeply dipping narrow vein orebody.

Oct 1, 2001

By A. J. Hyett, R. D. Reichert

"A laboratory and field research program was conducted to investigate the major factors influencing bond capacity of grouted cable bolts. The results indicate that cable bolt capacity most critically depends on the grout uniaxial compressive strength (UCS), the radial confinement, and the embedment length.In the laboratory &apos;split-pipe&apos; tests were conducted using P VC, aluminum and steel pipes to provide radial confinement, and field test sites were chosen in granite, limestone and shale rock masses. For both datasets higher capacities were obtained under conditions of higher radial confinement. A correlation between the two was obtained through a comparison of the radial wall stiffness of the laboratory pipes with that of the field boreholes as measured using a high pressure dilatometer. Cable bolt capacity was found to increase with embedment length though not in direct proportionality.The use of low water cement ratio grouts (<0.40) can increase cable bolt capacities by 50% to 75%. This effect is maximized under conditions of high radial confinement. However, the use of super thick grout paste (0.30 and less) may be both impractical and undesirable, first because of their limited pumpability and second because of their inconsistency in strength. Grouts with a water cement ratio of between 0.35 and 0.40 are recommended for practical cable bolt applications."

Jan 1, 1992

By Fred E. Gray

The mill of Bralorne Mines, Limited, is located on the government highway in the Bridge River mining district of British Columbia, approximately fifty miles northeast of Shalalth, the shipping point on the P.G.E. railway. Prior to 1931, the property now owned by Bralorne Mines, Limited, was operated by Lorne Gold Mines, Limited. During the early operation of the mine, the ore had been treated at various times in one of three small amalgamation mills on the property. With the succession to ownership by the Bralorne Mines, Limited, work was started on construction of a new mill of approximately 100 tons capacity per day. The new mill was put into operation in the month of February, 1932, and since that date has been in continuous operation, milling an average of slightly over 3,000 tons of ore a month. The ore treated in the Bralorne mill is a gold-bearing quartz containing a very small amount of silver. About 75 to 80 per cent of the gold is in the form of free gold, the principal remaining portion being intimately associated with pyrite and arsenopyrite. The gangue rock is quartz, together with varying but relatively small amounts of altered diorite or albitite. In some of the ore, usually the higher grade portions, there is also considerable talc, which forms much slime in grinding. The mill is situated near the portal of the main haulage tunnel and the ore is received directly from the mine ore-trains, which dump on to the grizzly over the coarse-ore bin of the crushing plant. Figure 1 shows the flow-sheet of the mill as it is now being operated. Various changes have been made in the flow-sheet and in the reagents since the commencement of operations, and doubtless minor changes will continue to be made in order to increase the efficiency of the mill. Among the more important changes were those from two-stage to single-stage grinding, and from amalgamation plates to blankets. The change in the crushing was made because too much crushing was done when both primary and secondary mills were employed.

Jan 1, 1933

By D. A. Trotter

"Low-pressure sodium light sources have been available for several years, but have not received wide acceptance in underground mining. This is because they are difficult to operate using DC power, they are not an intrinsically safe light where explosive gases may be encountered and they give poor colour rendition.With the need for energy conservation, several Canadian hard-rock metal mines are now changing their lighting to low pressure sodium, as it has the highest efficacy of any light source in terms of lumens per watt. Studies have pointed out several other advantages as well. Glare can be controlled, they penetrate fog well, they are easily maintained, they have a long life and they give the highest visual acuity when compared to other types of lighting. As well, in an underground mine, contrast is much more important than colour for task identification. For close work, the colour problem is alleviated with the use of cap lamps.Case studies are presented from Canadian practice. These show how the lights are modified for underground use, calculations preceding light installation, and how and where the lights are installed in the underground environment. Mention is made of worker reaction to the lights and possible physiological effects.IntroductionThe importance of good underground lighting to the total environment of mining cannot be overemphasized. In addition to the obvious benefits of improved worker morale, available studies show that good lighting practices reduce accident severity and frequency as well as increase production."

Jan 1, 1982

By Ward E. Kilby, Bruce I. Mcclymont

"Data from the South Fork Pit Area of the Bullmoose deposit in northeastern British Columbia are used to demonstrate the usefulness of microcomputers to the on-site geologist. The technique utilizes a series of digital surf aces in the form of a network of points to define various geologic parameters such as seam positions, topography and coal quality characteristics. Manual digitizing, kriging and combinations of these techniques are used to calculate these digital surfaces, the best method depending upon the type and quality of the data in question. Digital surfaces, each modelling a specific feature when combined and manipulated with the computer form a powerful tool, the deposit model. The resultant model, containing all the surfaces, is used to examine seam and inter-seam thicknesses, deposit volumetrics, seam quality characteristics and the adequacy of sampling.IntroductionCoal deposit modelling using computer-based techniques has become routine. However, a geologist working in the field, without access to mainframe or minicomputer, ha s considerable difficulty implementing these procedures. However, microcomputers, which are portable and inexpensive can handle exploration data, perform various geological analyses, and produce deposit models virtually at the same time as the data is being collected. For the on-site geologist this means that quick access to the results of such modelling could point out inadequacies in deposit definition and trends in coal quality deserving investigation."

Jan 1, 1985

By Evans B. Mayo

ABSTRACT Orange Footwall &apos;sill&apos; is locally concordant locally discordant, with the structure of its sedimentary walls. The sediments were folded in two directions. Folds, following both these directions, are preserved in the concordant portion of the &apos;sill&apos;. It seems, therefore, that the porphyry has replaced the sediments, thus preserving within itself their structure. During replacement, the nascent porphyry may have been much weaker than its walls. Accordingly, under directed pressure, the porphyry could have flowed locally, disarranging the replaced structures within it and developing a flow structure discordant with the folds in the sediments. Some such action may account for the discordant parts of the &apos;sill&apos;. INTRODUCTION The senior author has seen certain granitoid massifs that have an internal structure vastly different from, and discordant with, the structures in their wall rocks. It seems that? such massifs have moved independently of their surroundings. Yet, a structure section elsewhere in the same mountain range may reveal granitic rocks with internal structures that appear to continue the structure of the invaded rocks. In such a case, it is at least thinkable that the granite has replaced the older sediments or volcanic rocks. In February, 1950, the writers mapped, on 15 level of the Nickel Plate mine, near Hedley, B.C., a diorite or gabbro porphyry &apos;sill&apos; that, in one cross-cut (1503), appeared to be quite concordant with the wall-rock structures, whereas in another cross-cut ( 1500) about 100 feet to the south, the same porphyry was discordant (see Figure 1).

Jan 1, 1951

By David L. Anderson

"The objective of this paper is to describe the potential impact of inter-provincial competition f or new output capacity on the Canadian potash industry. It will be shown that the ramifications of such actions are potentially severe, especially since the potash industry is one of the few non-fuel minerals in which Canada purportedly possesses a significant degree of market power. More specifically, the paper addresses the impact of possible expansions in New Brunswick, Manitoba and, perhaps, Saskatchewan. The findings suggest that such initiatives could result in substantial excess capacity and the dissipation of monopoly rents. In summary, given the market structure of the industry, it is unlikely that the employment and economic effects associated with industry expansion will offset the loss in national welfare attributable to rent dissipation.IntroductionThe objective of this paper is to discuss the potential impact of inter-provincial competition for new output capacity on the Canadian potash industry. The ramifications of such competition are potentially severe: given that the potash industry is one of the few non-fuel minerals in which we purportedly possess a significant degree of market power(1), it is important that sound supply management practices are followed. However, possible initiatives by New Brunswick, Manitoba and, perhaps, Saskatchewan may initiate an inter-provincial competition which could result in substantial excess capacity and the dissipation of economic rents(2). Given the market structure of the industry, it is not intuitively obvious that the employment and economic effects associated with industry expansion will offset the loss in national welfare attributable to rent dissipation."

Jan 1, 1985

By Nosa O. Egiebor, Kafui Nyavor

"The effectiveness of sulphuric acid, nitric acid, and hydrogen peroxide pressure oxidation on the cyanide extractability of gold from a double-refractory concentrate is presented. Whileover90% of the sulphide content could be oxidized by either of the two acid pretreatments, only 65% was achieved by the peroxide oxidation. Carbon oxidation by both acid and peroxide pressure oxidation were less than 15%. Although the peroxide pressure oxidation pretreatment resulted in much lower sulphur and carbon oxidation, it gave pretreated residues with decreased levels of preg-robbing activities and higher gold recoveries during subsequent cyanidation, thus indicating some deactivation ofthe preg-robbing carbon during pretreatment with hydrogen peroxide. The refractoriness due to carbon preg-robbing activity was found to contribute more to the refractory behaviour of the concentrate than the occlusion of gold particles by the sulphide mineralization.IntroductionGold ores and concentrates are classified as refractory when a significant portion of the gold content cannot be extracted efficiently by conventional cyanidation, even after fme grinding (Weir and Berezowsky, 1984); (Demopoulos and Papangelakis, 1987). The refractory behaviour of precious metal ores and concentrates is generally attributed to two main factors: The presence of carbonaceous materials which could cause preg-robbing activity during cyanidation (Zaitseva et al., 1973); (Nice, 1971); Scheiner et al., 1971); (Eisele et al., 1983), or occlude gold-bearing minerals (Wells and Mullens, 1973); (Gasparrini, 1983); (Chen and Reddby, 1990), and the occurrence of sulphide minerals which can occlude gold, thus reducing the access of lixiviants (Schwartz, 1944); (Weir et al., 1986); (papangelakis and Demopoulos, 1990); (Michaelis, 1989); (Schweigart, 1965). When the refractoriness is due to a combination of these two factors, the ore or concentrate can be referred to as being ""double-refractory"". Because of the rarity of gold ores exhibiting this double-refractory phenomenon, only a few studies have been carried out on their suitability for pretreatment by existing techniques."

Jan 1, 1992

By E. Busse, J. E. Burgener, J. G. Eacott, M. C. Robinson, P. E. Burgener

"This paper presents a preliminary assessment of the technical and economic feasibility of a caustic leach - electrowinning process for the recovery of zinc and lead from electric arc furnace baghouse dust at a mini-steelplant. Recent studies and literature are referenced briefly as they pertain to the formation and characterization of dust, toxicity considerations and alternative dust treatment and disposal options.Laboratory testwork results, published data, pilot plant experience and anticipated influences resulting from recycling residues are used for the purpose of developing a conceptual design for a caustic leach - electrowinning plant to treat 15,000 tonnes/year of dust at a one million tonnes /year capacity steelplant in Canada.Target economic studies, comprising preliminary estimates of capital and operating costs, revenues and rate of return are presented. Economic and commercial considerations concerning the relative merits of dust treatment at a centralized facility compared with an on-site plant are discussed.IntroductionThe treatment or disposal of mini-steelplant electric arc furnace (EAF) baghouse dust has been given increasing attention in recent years for two principal reasons. Firstly, the dust is now classed as a hazardous waste material under V.S. EPA regulations which prohibit its disposal in dumps other than controlled landfill sites. Secondly, the dust contains certain metal values, notably zinc and lead, which may be economically recoverable, depending on the costs associated with disposal resulting from enforcement of the EPA regulations. Other metallurgical dusts and waste materials, from both ferrous and non-ferrous operations, may require the same considerations as EAF baghouse dust.Several studies have been carried out to examine various aspects of dust treatment but few commercial plants are in operation. Technology employed uses pyrometallurgical techniques. Commercial-scale hydrometallurgical plants are not known to exist although small-scale plants are frequently more economically attractive than their pyrometallurgical counterparts which generally require economies of scale to be viable.The concentration of mini-steelplants in northeast V.S.A. and southeast Canada merits study to determine whether or not dust treatment for metals recovery is a commercially feasible alternative to disposal.This paper examines the technical and economic feasibility of a caustic leach - electrowinning process for the recovery of zinc and lead from EAF baghouse dust at an on-site ministeel plant processing carbon steel scrap and discusses economic and commercial considerations pertaining to dust treatment at a larger, centralized facility."

Jan 1, 1984

By J. Olaf Sund

"THE November issue of the Bulletin carried in it ""Origin of the New Bruns1viclc Gypsum Deposits"" by J. Olaf Sund. This paper was a digested account of a Master's thesis at the University of New Brunswick which was a very useful compendium of information of gyp-sum in New Brunswick. It was a warded the President' s Gold .Medal and the First Prize in the Graduates' Section of the Students' Essay Competition. The present writer presents his congratulations to the winner of the competition. At the same time he must comment on the use of certain terms and on certain conclusions presented in the paper.The term ""unconformable"" has been used in several places in the paper to describe the relationship of gypsum to anhydrite in various deposits in New Brunswick in a sense which is quite alien to the accepted meaning. It has long been known tl1at the gypsum at the surface or near the surface in deposits in the Atlantic Provinces has come from hydration of anhydrite by surface and ground waters. The gyp-sum must be looked upon then as an alteration or even a weathering product. It cannot in this sense be called ""unconformable"" and thus arguments using the word in the accepted sense are invalid."

Jan 1, 1960

By David M. Parkes, George E. Davies

"Mathematically, the proposed formula is: ""Human Effectiveness + Technological Improvement = Success in the Nineties"". A brief review is made of geology, level of technology, management and labour situations, and range of production costs in coal producing countries. This comparison shows keen competition for Canadian coals, especially from the People&apos;s Republic of China, South Africa and Australia. Domestic competition comes from nuclear energy, hydro-electric generation, natural gas (if permitted) and eastern United States coal.The huge increase in the size and power of surface mining equipment in the last forty years led to modern large-scale open pit mining. While conventional truck and shovel operations will continue to be widely used, more continuous mining and conveying systems will be installed as pits become deeper and haul distances longer. Computer systems will become more sophisticated and their applications more widespread, leading to higher productivity and closer control of all operations and equipment performances and to partial or complete automation of certain operations.The underground revival will be driven by a new generation of mining people, cooperating to produce over 3 million t/y from 300 m longwall faces retreating over 3 km resulting in mine productivities of over 40 tonnes per man shift, as is already achieved in several mines throughout the world. Continuous operation using on-line control system will assist in consistent production with availabilities over 75%."

Jan 1, 1991

By R. D. Brown

"Taxation tends to be a depressing subject. Taxes are unfair, taxes are too high and, above all, taxes are too complicated.In a recent address to the Canadian Tax Foundation, the author discussed in a rather more lighthearted way the possible causes of the complexity of the present Canadian taxation system. In order to provide an element of relief in this series of articles on taxation matters, extracts from these remarks are quoted below :"

Jan 1, 1976

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 L. C. Galloway, G. L. Tiley

"Mine hoist brakes must meet the following statutory performance criteria:- There should be two independent braking systems; at least one should act directly on the hoist drum.-If one brake fail s, the others should be able to retard and stop the hoist safely before the descending conveyance, carrying the rated load, reaches any obstruction.- When all brakes apply, decelerations should not be so violent that men travelling in the conveyance are injured.- The brakes shall not overheat and fade during an emergency stop.This paper discusses design principles and capacities of caliper and disc type brakes, when applied to double drum and friction hoists of equivalent capacity.IntroductionThis paper is about the brakes that are used on mine hoists; their functions, especially in emergencies, typical design, and how they are operated, controlled, tested, and adjusted.There are two basic types of mine hoists:1. Drum hoists, where the ropes are attached to, and coil on drums. The simplest system has only one drum. Most such hoists, however, have two drums, attached to a common shaft. Ropes are wound on each drum in opposite directions, so that when one conveyance is being raised, the other is lowered. The conveynaces may travel in vertical or inclined shafts. In the latter case, the hoist s are referred to as slope hoists.2. Friction hoist s, where the headropes are not attached to the wheel, but are in contact with it for an angle of lap of, typically, between 180 and 195 degree s. Forces are transmitted from the hoist wheel to the head ropes by friction.The lower ends of the conveyances are connected to balance ropes , approximately the same weight per foot as the headropes."

Jan 1, 1986

By J. F. K. Brown

MR. T. L. McCALL: Planning ahead in coal-mining is essential, but the question may be raised, just how far ahead can we plan. You can overdo it: chat is, you can get in a rut. Never let planning get a hold on you to chat extent. You must be prepared to deal intelligently with any new conditions that arise, and to apply new discoveries. It may become necessary to abandon ? .your plan, make the best you can of the ground you have developed, and start again, with a new plan. So far as the submarine workings of the Dominion Steel and Coal Company are concerned, we cannot know definitely what lies ahead of us under the sea: we must ?base our tentative plans on assumptions, and, as we meet changing conditions, we must change our plans. In the case of inland mines it is possible to bore in advance, and consequently it is generally possible to set out your plans in advance, block out a section of the mine, and develop to obtain a uniform product for a whole year, or perhaps even longer. MR. J. B. MORROW: While planning in coal mining, we must bear in mind chat the consumer also is planning ahead. Some people will tell you that, in ten years time, the demand is going to be all for pulverized co al; others believe that the field for such fuel is limited. Needless to state, planning for a pulverized-coal market is quite a different matter to planning for a general grade, ore stoker, market. In planning, therefore, our endeavour must be to keep a jump ahead of the work being undertaken by the anthracite producers. This year, they are spending about two million dollars-money contributed, not by the Government, but by the industry itself-in the study and promotion of new and improved ways of burning anthracite. For example, they are perfecting small hot-water heaters, and one they have brought out weighs only about ten pounds. I feel that research of this type must be regarded as an essential part of planning in coal mining. We, in the soft-coal industry, are also planning types of more efficient burning equipment and doing other investigational work.

Jan 1, 1937

By F G. Cooke

"This paper describes a medium-sized copper mine's results in making innovations and changing operational practices to combat increasing expenditures due to higher labour and supply costs, extended workings, scarcity of experienced manpower and problems created by deteriorating ground conditions.OPEMISKA COPPER MINES (QUEBEC) LIMITED is located at Chapais in the Chibougamau area, in central eastern Quebec, approximately 300 miles north of Montreal and 150 miles north west of Lake St. John. The latter area, developed by lumbering and farming, has supplied the majority of the employees, who, with training and experience and a desire to work and improve themselves, have become the backbone of the Company's 600 personnel.Opemiska began production in 1954 at a rate of 400 tons per day, using diesel power and road transportation. The rate was progressively increased and, by 1959, with hydro-electric power and rail transportation, the mine had reached its present production rate of 2,000 tons per day. It has produced concentrates containing over 430 million lbs of copper."

Jan 1, 1968

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