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By M. Ghamgosar, Erarslan N.

Rock cutting includes many unknown parameters which result in different consequences of the different cutting conditions. However, based on the current suggested models for rock cutting, there are some critical parameters that control the fracture initiation and propagation in the rock domain. In general, there are two major cutting tools are used in rock cutting: drag bits and indenters. Different mechanical attacks of cutters result in different fracture models. For example drag bits break the rock parallel to the rock surface, which is called ‘undercutting’ while indenters cut rocks by pressing normal to the rock surface. Both tools cause rock failure by inducing tensile cracks in the rock. However, drag bits induce more tensile cracks compared with the indenters. The full benefits of improvement in rock cutting efficiency will arise from a clear understanding of rock fracture mechanics principles. Therefore, fracture mechanics principles will be applied to the rock cutting as the rock fragmentation process is based on the rock fracturing. The Oscillating Disc Cutting (ODC) has more advantages than drag bits and disc cutters. The forces transmitted back through the cutting head are much lower with ODC. Although ODC attacks rock in much the same way as drag bits, a combination of the oscillating action of the cutter and the undercutting mode produces the lower cutting forces and causes rock fatigue. Fatigue phenomenon in rock has advantages for the rock breaking by applying less effort and energy due to the cyclic loading. The aim of this study is using the Extended Finite Elements Analyses (XEFM) numerical modelling for simulating the ODC cutting with different cyclic loading conditions. An accurate prediction of numerical investigation requires detail laboratory experiments. A series of laboratory tests were performed to obtain the fracture toughness values of our Monsonite rock samples under various cyclic amplitude and frequency values. The numerical results showed different types fatigue damage mechanisms due to the various cyclic loading conditions. Thus, modelling and understanding the crack propagation behaviour depending on different amplitude and frequencies are believed very important for the dynamic rock cutting researches and rock cutting machine manufacturers.

Jan 1, 2015

By Harold S. King

TWO summers ago I had the privilege of visiting No. 18 colliery at Glace Bay. Underground, we travelled along the haulage-way behind a powerful electric locomotive. The motor in this locomotive began to smoke badly and a carbon tetrachloride type of extinguisher was used several times during the trip. At the time, I noted a strong odour of phosgene. On my return to Sydney, I spoke to Mr. Harold Gordon, Assistant to the General Manager of the Dominion Steel and Coal Corporation, and warned him of the danger of using this type of fire extinguisher in confined spaces, since it is a well known chemical fact that phosgene, a dangerously toxic gas, is formed by the decomposition of carbon tetrachloride. This danger does not seem to be widely recognized, so it seems advisable that a more general warning be published. Attention was first drawn to the danger by the death of two men in the United States Navy Department subsequent to breathing fumes from carbon tetrachloride used in a fire, and when an employee of the Bureau of Mines also was overcome while fighting a fire with carbon tetrachloride liquid. These accidents led to an investigation of the decomposition products of carbon tetrachloride by a group of workers in the Research Laboratory of the Pittsburgh Experimental Station, U.S. Bureau of Mines, the results of which were published in the October, 1920, number of the Journal of the .Franklin Institute (1). Their experiments were conducted by two methods. The first consisted in applying the liquids to actual fires and -to hot metal in a closed room of 1,000 feet capacity, where the gaseous products, mixed with air, could be retained and analyzed. The second method was to pass the vapour:s in air through heated tubes of iron or quartz, where the humidity of the air and the temperature could be controlled.

Jan 1, 1939

The purpose of this paper is to present the methods used in ground water control and the considerations that affected the development of these techniques. Production at Knob Lake is currently proceeding at depths which may be as much as 200 feet below the original standing water table. In order to produce a more saleable product and to improve operating and maintenance conditions, it is necessary to depress the water table below the mining level. Considerable success has been achieved by drilling deep wells in strategic locations and installing vertical tur-bine pumps at depths of up to 400 feet. This method is especially suitable for operation under severe winter conditions and has reduced the detrimental effects by a far greater extent than other methods of water control, Spring runoff is handled in open sumps, but all other water from four mines, with flows exceeding 16,000 g.p.m., is pumped all year 'round from about thirty-five wells. THE Knob Lake operation of the. Iron Ore Company of Canada is located on the Quebec-Labrador border, 320 miles north of Sept-lies, a seaport

Jan 1, 1965

The purpose of this paper is to present the methods used in ground water control and the considerations that affected the development of these techniques. Production at Knob Lake is currently proceeding at depths which may be as much as 200 feet below the original standing water table. In order to produce a more saleable product and to improve operating and maintenance conditions, it is necessary to depress the water table below the mining level. Considerable success has been achieved by drilling deep wells in strategic locations and installing vertical tur-bine pumps at depths of up to 400 feet. This method is especially suitable for operation under severe winter conditions and has reduced the detrimental effects by a far greater extent than other methods of water control, Spring runoff is handled in open sumps, but all other water from four mines, with flows exceeding 16,000 g.p.m., is pumped all year 'round from about thirty-five wells. T HE Knob Lake operation of the. Iron Ore Company of Canada is located on the Quebec-Labrador border, 320 miles north of Sept Iles,

Jan 1, 1965

By L. A. Anestiev

A method based on use of calorimetric data for the determination of solidification kinetic parameters is proposed. The method incorporates recent theories of nucleation and growth and allows modeling heat fluxes observed in calorimetric experiment. Statistically optimal estimations of the kinetic parameters, which include the activation's energies of nucleation and growth, are derived from experimental data by means of nonlinear regression analysis. The method is applicable to pure substances and alloys. The evaluation of the kinetic parameters characterizing solidification of pure Al is used for clarifying and exemplifying the method.

Jan 1, 2004

By E. J. Marcotte

"IntroductionDevelopments in the preparation, hydraulic transportation and placement of classified mill tailing as an effective backfill and support for mining excavations, have made feasible several advancements in mining methods that are safer and more economical. Hydraulic backfill systems have played an integral part in the development of more efficient cut-and-fill and blasthole stoping.The hydraulic transportation of tailing fill has made possible the elimination of expensive and laborious transportation, placement and spreading of gravel type fills. Also, in cut-andfill stopes, the use of hydraulically placed consolidated fill has largely eliminated the need to use extensive timbering for floors and supports, previously necessary when only gravel type, waste rock or unconsolidated tailing fill was used .Another important advantage of using mill tailing as backfill is that it decreases the need to contain a large portion of the mill solids waste in a surface disposal area and thus reduces environmental and ecological problems.Tailing Fill PropertiesConsolidated tailing fill consists of deslimed mill tailing and Portland cement. These two materials are mixed together in various proportions to form a high density slurry which is transferred underground by gravity through boreholes and pipelines. After placement underground, the water is drained off and the mixture is allowed to set. The strength of the consolidated fill is dependent on the cement content, particle size distribution and curing time. A typical tailing/ cement ratio used for bulk filling in stopes requiring vertical wall support is 30:1. Ratios ranging from 8:1 to 5: 1 are used for stope floors. High pulp densities minimize segregation and loss of cement during placement as well as reduce the amount of drainage water to be handled."

Jan 1, 1989

By H. J. McQueen

Pressure welding is a solid state joining technique that depends on bringing the parts into sufficiently close contact that inter-atomic bonds are achieved. Pressing is more effective at elevated temperatures where plastic flow causes the asperities to collapse; improved application conditions are derived from hot-work research to clarify temperature and strain rate dependence of hot strength and ductility. The substructure evolution systematically studied in hot working to determine dynamic recovery or recrystallization is applied to clarifying that developed in welding. The various processes are affected differently by work-piece geometry and final shape requirements. In addition to pre-cleaning of the surfaces, the plastic flow helps disperse the remaining oxide layers as was originally exemplified in blacksmith hot forging of layered sword blades and in bellldie welding of wrought iron tubes. The presentation critically compares the utility for various materials and configurations of simple pressure, ultrasonic application, diffusion, explosive, rotary and linear friction and friction-stir processes. Diffusion bonding (primarily Ti) with light cleaning, low pressure, little distortion in protective furnace atmosphere contrasts strongly with the heavy upsetting in friction welding, or complex alloy mingling and substructure variations in friction stir joints.

Jan 1, 2011

By C. Piribauer, E. Feichtenhofer, A. McEneaney

"As part of a major diversification project, RHI AG, through its plant in Drogheda Ireland, has developed a Caustic Calcined Magnesium Oxide (CCM) for use in the Cobalt (Co) & Nickel (Ni) hydrometallurgical extraction industry. In the course of the project, the company investigated the chemical and physical properties of a number of different Magnesia’s used in Co & Ni hydrometallurgy applications and has been able to determine the important parameters for a successful Magnesia for this application. A number of live plant trials have confirmed the results of this testwork and the company is now proceeding to produce this product in commercial quantities at Premier Periclase Ltd., the RHI AG plant in Drogheda, Ireland. This paper will outline the development work conducted by the company and highlight the important chemical and physical properties that make a successful CCM. Much of the research was conducted at the RHI Technology Centre in Leoben, Austria. In addition, a number of external laboratory studies were conducted on behalf of RHI AG. The result of this work has allowed the company to develop a Magnesia product with optimised properties for use in the Cobalt and Nickel hydrometallurgical extraction process.INTRODUCTION Premier Periclase is part of RHI AG, a globally operating supplier of refractory products, systems and services, headquartered in Vienna, Austria. The company produces Magnesia from seawater at its plant in Drogheda, Ireland. While the main focus is on production of refractory grade Dead Burned Magnesia for the steel industry, the plant also produces a number of different grades of Caustic Calcined Magnesia as well as Magnesium Hydroxide products. As part of a major project to diversify the company’s product base, the use of CCM in the Cobalt (Co) & Nickel (Ni) hydrometallurgical extraction industry was investigated. One of the company’s highly reactive grades of Caustic Calcined Magnesia was found to be particularly suitable for this application. In an effort to understand what makes a successful Magnesia for hydrometallurgy the chemical and physical properties of different Magnesia’s used in Co & Ni hydrometallurgy were investigated. This paper and conference presentation outlines the findings of this process."

Jan 1, 2017

By D. A. Barr

High-grade gold-silver mineralization associated with electrum and argentite was discovered in a quartz vein at the Chappelle property, 273 km north of Smithers, B.C., in 1969 following a regional geochemical reconnaissance program in the Cassiar-Omineca Mountains. Subsequent exploration resulted in the discovery of numerous quartz veins with associated precious-metal values in a belt 17 by 3 km in area centrally located within Toodoggone Group volcanic and sedimentary rocks of Lower to Middle Jurassic age and a window of Takla Group volcanic rocks of Upper Triassic age. More detailed investigations, consisting principally of 5677 m of surface drilling in 57 holes and crosscutting, drifting and raising on Chapelle Vein A, has outlined a high-grade gold-silver-bearing shoot with a strike length of 200 m, an average width of about 3 m and extending to an average depth of about 40 m below surface.

Jan 1, 1978

By C. E. Rodgers

WHEN the writer was engaged early last year by Canadian Comstock and its subsidiary, the Metropolitan Electric Company, to act as Consulting Mining Engineer in connection with the layout and equipment of the new ore-dressing laboratories at Laval University, Quebec, the metallurgical laboratory section of the School of Mines building was completely erected, including plastered walls, partitions, etc., and finished concrete floors. At that time, however, no equipment had been ordered, except three Dominion ball-mills and two Bell screening machines. ADVANCED OR CONTINUOUS LABORATORIES The continuous laboratory section of the Department occupies the basement and three floors of the building, with an approximate floor area of 9,000 square feet. Because of limitations imposed by the design of the building (height and arrangement of rooms, strength and design of floors, etc.), modifications of layout from what otherwise seemed most desirable were, of necessity, made. These included: (a) Omission of automatic sampling of the dry ore. (b) Complete elimination of inclined belt-conveyors through floors. (c) Exclusion of bucket elevators for either dry or wet ore transfer. (d) As a substitute for grill-covered drains and floor sumps, drainage from sections or from individual pieces of equipment was piped to a disposal system in the basement. (e) Substitution in several instances of fabricated steel in place of the usual concrete foundations for machinery. (f) Reducing floor cutting and area of such opening to a minimum. Ore storage and chute capacity above the basement level was also minimized to reduce total weight.

Jan 1, 1941

By F. W. Gray

Summarized Foreword This paper is one of a series arranged by Institute Divisional Committees for the Fiftieth Anniversary Meeting, reviewing the experience of the major mining and metallurgical industries during the life of the Institute. The viewpoint is national and broadly technical. Geology is stressed on a continental scale without regard for provincial boundaries. The boundary between Canada and the United States is, however, so decisive a factor in our coal-mining economics and our political evolution that mention of its implications cannot be avoided. The Laurentian Shield in Canada makes the occurrence of coal deposits a geological impossibility between the St. Lawrence Lowlands and the Great Plains. All but five per cent of Canadian coal resources occur west of Winnipeg. The utilization of this ninety-five per cent of our coal wealth has to date been a consequence of transcontinental railways' development, and the small fuel needs of thinly populated wheat farming and cattle-raising territory, in what- to judge from the development of mixed farming and greater population density of Manitoba- is merely an initial stage of agricultural intensification and accordant population growth. There is no useful purpose in measuring coal resource against consumption rate in the West as a whole, because the resource is but partially known, and it is difficult to believe that industrialism based upon coal utilization is in any but its infant stage of growth. Canada west of Winnipeg possesses, moreover resources of petroleum and natural gas, which, together with the power-potential in the long watershed of the eastern slope of the Rocky mountains, give to population centres such as Calgary and Edmonton a choice of energy resources that is almost an embarrass des riches.

Jan 1, 1948

By C. S. Lord

"AbstractThe slow progress of conventional geological reconnaissance of the northern Canadian Shield during the past twenty years clearly indicates the need for a radically new field technique. Operation Keewatin, involving the use of helicopters as the traversing vehicles, was planned and executed by the Geological Survey of Canada in response to this requirement.About 57,000 square miles of District of Keewatin, N.W.T., were mapped during the 1952 field season in appropriate detail for publication at 1 inch to 8 miles. The Operation disclosed about 14,100 square miles of Precambrian sedimentary and volcanic rocks ranging in •age from Archaean to Late Proterozoic. About 7,700 square miles of this area are underlain by greenstone. This work was accomplished in a field season of 113 days, including the spring break-up. Routine aerial geological observations were made from two helicopters flying about 300 feet above the ground; these observations were checked by more than 1,700 landings and about an equal number of aerial observations from heights of less than 50 feet. Logistical support was •provided by a Norseman aircraft on skiis or floats. Combined helicopter and Norseman flying time was about 990 hours. More than 1-00 square miles were mapped per helicopter-hour, and about 815 square miles were examined each day that both helicopters operated. The reconnaissance cost about $207,000, or $3.63 per square mile mapped.As a result of this trial use of helicopters there is now available a reasonably proven method whereby an acceptable geological reconnaissance of the barren grounds of the Canadian .Shield within the Districts of Keewatin and Mackenzie might be completed within a decade. Thus, within a few years, it could place at the disposal of the prospecting and mining fraternity data which, by conventional methods, might not be made available to this generation. Due weight must be accorded this time factor when evaluating the aerial technique."

Jan 1, 1953

By J. L. Llanca

The New Level Mine project (NLMP), the planned underground expansion of the El Teniente mine in Rancagua, Chile, is expected to reach a daily extraction rate of 137 to 180 ktpd upon achieving full capacity. Production is planned to start in the year 2017 and the current plan is to meet that target through two development phases, from the year 2012 to 2014 and from the year 2015 to 2017. To achieve the 2012 to 2014 underground development schedule, the ventilation requirements have been estimated in the range of 189 m3/s (400 kcfm), and cannot be made available without significant modifications to the current system of El Teniente. As a result, a certain number of alternatives were explored to find a solution to this shortfall, for example, adding raises to generate parallel airways and installing fans to reinforce the current ventilation system. From the alternatives studied, the installation of a second main fan (system) in parallel to an existing one was identified as the best solution, and selected for implementation, however the location was not ideal and there were concerns as to the operation of both fans once the second fan was installed. This paper presents the study used to estimate the operational points of both the current and the new fan, and to justify the parallel installation of the additional main fan. An additional computational fluid dynamics study was undertaken to validate the operational point, given the particular geometry of the fan?s location and placement, to guarantee a stable operation of the fans. Finally, the protocols arising out of this work for starting the fans, and operating them in parallel to avoid generating a stall condition and damaging the investment are discussed.

Aug 1, 2013

By D. H. Flather, J. W. Hendry, K. Drover

Black Hawk Mining Inc. has completed a comprehensive program on the prediction and management of acid rock drainage (ARD) at their Keystone Gold Mine (Keystone) near Lynn Lake, Manitoba. The program, initiated in 1994, followed a phased approach utilizing initial acid-base accounting (ABA) results and subsequent laboratory kinetic testwork to define site-specific sulphide oxidation and neutralization consumption rates in waste rock. Net acid generating waste rock at Keystone was defined through the kinetic testwork as waste rock yielding a net potential ratio (NPR) of less than two. A preliminary waste rock management program based on blending of potentially acid generating and acid neutralizing waste rock was advanced. Subsequent refinement of the management program followed the analysis of over 1580 ABA samples collected from individual blast holes during the initial bench development phase of the Keystone pit. Uncertainties in actually achieving adequate blending within the dumps at a mining- scale resulted in the development of a revised waste rock management program based on segregation. Recognizing that any successful management plan requires that the ARD characteristics of the waste rock be identified prior to in-pit blasting, the extensive ABA database was utilized to develop a rapid characterization scheme. By implementing a characterization scheme based on total sulphur concentrations and fizz rating, waste rock could be quickly segregated without delaying the natural flow of ore from the pit. Interestingly, it also became apparent that gold values were strongly correlated with total sulphur, such that traditional fire assays were supplanted with a simple and more cost-effective total sulphur determination. The program highlights the importance and benefits of collecting and exploiting data beyond that necessary to acquire appropriate development permits.

Jan 1, 2000

By C. W. Taylor, F. L. Martin

"THE DICTIONARY defines Metallurgy as the ""science or art of separating metals from their ores and refining them for use"". In these days, however, such a definition is not detailed enough.The modern science of metallurgy is based on two fundamental sciences, physics .and chemistry, and is sub-divided into two major fields: Process Metallurgy and Physical Metallurgy. These fields of metallurgy are now so comprehensive and involved that even the graduate metallurgist has to specialize in one or the other.In recent years, the relatively new science or technology of non• destructive testing has also entered the industrial scene, with tremendous impact and ramifications. So much so that, certainly, no .discussion on metallurgy can be complete without including some reference to it.Obviously, one paper cannot hope to cover in detail the relationship of the whole science of metallurgy to the mining industry. Consequently, only a very brief reference will be made to the field of Process Metallurgy, our major concern being with Physical Metallurgy and Non-Destructive Testing."

Jan 1, 1960

By Silvana Costa

The quality of life in remote mining communities is a significant factor that impacts the mining industry?s ability to attract and retain high quality workers in remote areas. The rapid growth of mining development, along with the shortage of skills and training globally are reflected in an increasing need to identify the ideal conditions for employee wellbeing and investigate ways to improve quality of life of miners and their families in remote locations.

May 1, 2007

By N. Waters

"Nickel saprolite ores are normally mined as feed to Fe-Ni smelters or Ni matte smelting operations. The smelting processes typically require high Ni cut-off grades of approximately 1.5 to 2.2% Ni, depending on the operation. These very high cut-off grades result in a significant portion of the saprolite profile being regarded as “waste” and hence having little to no value. The Starved Acid Leach Technology (SALT) was developed to recover nickel and cobalt from nickel saprolites and Caron plant residues. Relatively small amounts of acid are applied to ground saprolites or Caron residues in order to selectively leach nickel and cobalt. The leaching is performed atmospherically under low free acid conditions. Nickel and cobalt may be recovered from the leachate as a mixed hydroxide. The mixed hydroxide may be added directly to a saprolite smelting operation or refined separately. InCoR Technologies is advancing the application of SALT at a number of sites. Bench scale testing has provided a relationship between acid addition and nickel extraction in leaching. Conceptual engineering studies have been completed by SNC Lavalin. The simplicity of the SALT technology provides the benefits of low capital and operating cost and an expected rapid ramp up to full production.INTRODUCTION The recent history of hydrometallurgical nickel laterite treatment plants has demonstrated mixed financial and operational performance. Table 1 summarizes the next generation plants built after the financial and/or technical failure of the Bulong, Cawse and Murrin-Murrin plants in Australia. The Coral Bay plants (Line 1 and 2) stand out (and now Taganito) as relatively low capital cost, simple (no acid plant, production of mixed sulfide product), and modest in scale (10, 12 and 36 kt Ni/a). However, the other plants in the list (Ravensthorpe, Ramu, Goro and Ambatovy) are all characterized by financial and technical challenges. All plants have a very high capital cost ($67,000 to $120,000 USD/annual t of Ni production). Ravensthorpe was sold by BHP Billiton after a poor startup. Ramu has had a steady ramp up but only produces mixed hydroxide for refining by others. Goro has had an extended construction period (since 2001), is high cost and has been very slow to ramp up to design production rates. Ambatovy has had a steady ramp up."

Jan 1, 2017

By R. H. McCorkell

"Sample drops were evaporated on Lexan disks on which fission tracks were etched and counted after neutron irradiation. [U] = 0.01 ppb could be measured. This method is rapid, cheap, simple and accurate when sufficient control and checking is possible, but several types of error were encountered in its use, the natures and sources of which were investigated but not always determined. The most troublesome were ""annealing"" processes which sometimes altered the fission tracks so that they were not fully revealed, or acquired varying appearances, after etching. Several different annealing processes seemed to exist and seemed to be produced by alteration of the Lexan surface by dissolved components in the solutions and, perhaps, by radiation and local heating during neutron irradiation. The appearances of the etched tracks varied with the natures of the droplet solutions even when annealing appeared to be absent, and for this reason, standards are best prepared by additions of known amounts of U to sample solutions. Contamination of sample droplets by U-containing dust from the air is best avoided by preparing the disks away from areas where other U-analysis is being carried out.IntroductionFission tracks are regions of radiation dam age produced in solids by the fission of atoms such as 235U. They can be enlarged to sizes visible through optical microscopes by etching surfaces through which they pass with solvents in which the solids are slightly soluble. A sample to be analyzed for U may be placed against a film of a solid of negligible uranium concentration (the track detector) and irradiated with thermal neutrons in a nuclear reactor to fission 235U. The track detector is then etched and the number of tracks per unit area, ?, which is proportional to the uranium concentration of the sample, c, and the neutron do se, n, is found by counting through a microscope. Uranium in solutions ha s been measured by evaporating drops on track detectors, irradiating, etching and determining the number of tracks per drop, T(2,3,4,5). Extensive test s of this method are reported here."

Jan 1, 1983

By O. A. Ojo, N. Esmaeili

"The effects of brazing and use of composite powder mixture as interlayer material on hot corrosion resistance of brazed IN738 superalloy were studied. Brazing was observed to result in significant reduction in the hot corrosion resistance of the superalloy. However, application of composite powder mixture, which consists of additive superalloy powder, enhanced the hot corrosion resistance of brazed samples. It is also found that although the use of composite powder mixture increased hot corrosion resistance of brazed alloy, if the additive powder completely melts, which is possible during brazing, it can significantly reduce the hot corrosion resistance of the brazed joint. Elemental micro-segregation during solidification of the joint with completely melted powder mixture produces chromium depleted zones and consequently reduces hot corrosion resistance, since a uniform distribution and adequate chromium concentration is necessary to combat hot corrosion. This has not been previously reported in the literature and it is crucial to the use of composite powder mixture for enhancing the properties of brazed superalloys.INTRODUCTION Superalloys have been developed in response to the increasing demand for materials with higher resistance to corrosion and creep and also with higher mechanical strength at higher temperatures (Smith, 1981). Ni-base superalloys are predominantly used in manufacturing hot sections of gas turbine engine components. This is due to their high strength and corrosion resistance in extremely high temperature service environments which is typical for hot sections of gas turbine engines (Miglietti, 2009). The continuous demand for higher efficiency and output has resulted in the use of higher operating temperatures and gas pressure in modern gas turbine engines (Jahnke & Demny, 1983). Consequently, this has caused thermal and mechanical stresses which result in severe degradation and damage of gas turbine engine components due to creep, fatigue and hot corrosion (Zhang, Feng, & He, 2006). The decision to replace or repair damaged parts depends on the overall repair cost and expected life of the repaired components (Jahnke & Demny, 1983). However, in most cases, it is more cost effective to repair damaged parts rather than use a full replacement."

Jan 1, 2017

By Sandeep Singh Sandhu, Karanvir Singh Ghuman, Manjit Singh

"Cobalt based super alloy stellite 6 was weld cladded on AISI 304 L stainless steel using SMAW process in order to improve the wear resistance for tyre crusher blades. Microstructure characterization and micro hardness testing was performed on stellite 6 cladding. The suitable parameters viz. 80 Amp current with arc weaving technique was selected by performing bead on plate experiment were further used for depositing multipass multilayer cladding to achieve full filler chemistry at the top surface. Further GTAW process was used for re-melting the top surface of the cladding. Comparative evaluation of the claddings showed that TIG re-melting resulted in increased microhardness and wear resistance in comparison to as cladded specimens even with lesser deposition of material. It was observed that TIG re-melting improved the hardness from 603 HV0.5 kg to 712 HV0.5 kg. Micro structures of stellite 6 contained cobalt solid solution matrix along with inter dendrite chromium carbides which resulted in the increased micro hardness values. Pin on disc abrasion tests were carried out at room temperature and the worn out surfaces were characterized using SEM and EDS.INTRODUCTIONThe crusher blades are used in many industries for crushing various types of material and its wider applications in tyre rubber crushing mills, metal-powder crushers industries etc. Most of the crusher blades are damaged by the wear and impact loading conditions. It is because of metal to metal abrasion and the temperature also plays a vital role in blunting the cutting edges of these blades. The wear is the major cause which leads to loss of material and thus the productivity that can never be recovered (Kotechi et al., 1992). The wear can be reduced by coating of various super alloys which could reduce the behavior of metal degradation even in aggressive environments. Cladding of cheaper low alloyed material with expensive superalloys to enhance the performance of components at low cost has been investigated by many scholars (Deng et al., 2010, Kennametal, 2007, Lolla et al., 2014, Singhet al., 2014, J.N et al., 2003, Ramkumar et al., 2012). Many researchers have reported that cladding is an application of build-up deposits of specialized alloys to resist abrasion, high temperature corrosion and impact loadings. Cladding is used for providing required mechanical strength properties as well as inhibition of oxidation and other corrosive degradation. Coatings are used to protect the heat affected areas like tubes of fluidized bed combustor etc. (Kirchbner et al., 2008, Wang et al., 1994, Hocking et al., 1993, Ananthapadmanabhan et al., 1991, Staia et al., 2001). Coating techniques are widely used for the protection of turbine engine and boiler tubes against high temperature corrosion attack, power generation equipment, chemical process equipment, aircraft engines, pulp and paper processing equipment, bridges, rollers and concrete reinforcements, orthopedics and dental, land-based and marine turbines, ships. Coatings of stellite 6 are widely used in steam turbine blades and boiler tubes for power generation because of an excellent combination of impact, wear and other properties. It can maintain its properties even at high temperature and in harsh environments (Kobayashiet al., 1999, Alam et al., 2009, Munehru et al., 2009). The loading and unloading conditions experienced by the material may induce the surface cracks which lead to its breakage and leaving large pits in the surface (Meng et al., 1995). Many researchers have reported that the properties of cladded layers can be increased by various techniques such as controlling the current variations, dilution, heat input, laser and other re-melting processes, addition of special alloying elements, speed of weldingetc(C.M Anaet al., 2002, Kumaret al., 1999, Luo et al., 2012, et al., Madadi et al., 2011, Shin et al., 2003, Kuzucu et al., 1997, Sudha et al., 2008, Sawant et al., 2017, Houdkova et al., 2016, Ciubo"

Jan 1, 2017