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By Jean Howard

ThE formation of the (100) [001) texture in 3-1/4 pct Si-Fe strip was first reported by Assmus ef a1.l in 1957. Since then much experimental work has been carried out with a view to establishing the mechanism involved. The papers cited above state that the (100) [001] texture was developed in strip rolled from material melted and cast in vacuum. (The impurity content of the ingot is reported as 0.005 pct.) The present note records that similar results can be obtained in material processed by powder metallurgy. A processing schedule is described.which enables the texture to be formed in strip up to 0.010 in. thick, but there seems no reason why this should not be achieved in thicker strip, provided that large grains are developed after sintering. The materials were prepared from Carbonyl Iron Powder Grade MCP (particle size 5 to 30 p) of the International Nickel Co. (Mond) Ltd. The powder contains about 0.15 pct 0, 0.01 pct C, 0.004 pct N, <0.002 pct S, $0.005 pct Mg and Si, and 0.4 pct Ni— that is, it is substantially free from metallic impurities other than nickel, which is thought to be unimportant in the present work. The silicon powder was 99.9 pct purity, or material of transistor quality (ground in pestle and mortar). The mixed powders (3-1/4 pct Si to 96-3/4 pct Fe) are heated in hydrogen at 350" and 650°C to deoxidize the iron before sintering loose at temperatures between 1350" and 1460°C (depending upon the ultimate thickness of strip required) for up to 24 hr. The object of the high-temperature sinter is to develop a large grain size at this stage. Alternatively, the loose sintering can be done at a lower temperature followed by rolling or pressing and then annealing at temperatures between 1350" and 1460°C. Both methods produce large grains, which remain large throughout the process. The compact is then hot-rolled to approximately 1/8 in. with high-temperature interstage anneals if necessary. This step is taken to avoid intercrystalline cracking which would occur if the material of such large grain size were cold-worked. The bar is then annealed at 1050°C and reduced to its final thickness by approximately 50-pct reductions and 1050°C interstage anneals. Throughout the process the dew point of the hydrogen furnace atmosphere is maintained at about -40°C. Samples were annealed in hydrogen at various temperatures and times. Secondary recrystalliza-tion to (100) [001] was developed on the thinner material (i.e., up to 0.002 in.) by annealing in hydrogen at 1050" to 1200°C with a dew point of - 40°C or in vacuum (10-5 Torr) at 1050°C. With the thicker materials (i.e., up to 0.010 in.) the best results were obtained by annealing in hydrogen at 1200°C with a dew point of - 55°C. Complete secondary recrystal-lization to (100) [001] textures was obtained. Above these temperatures secondary recrystallization to (110) [001] tended to develop. The final annealing of samples was normally carried out with the samples placed between recrystal-lized alumina plates, but some experiments were performed with the samples suspended so that their surfaces were not in contact with anything except hydrogen, and these were equally successful in developing secondary crystals. An approximate determination of the proportion of material (before secondary recrystallization took place) having crystals with the (100) or (110) planes in or near the rolling plane showed that 11 pct of the sample had (100) and 16 pct (110). The method used for the determination is described below. A sample was annealed at a temperature just below the secondary recrystallization temperature and etched to reveal the (100) planes. The approximate area covered by crystals having (100) or (110) in or very near the surface was measured on the screen of a Vickers projection microscope. This was repeated for twenty positions chosen at random and a mean of the results calculated. The main hindrance to developing the secondary crystals in the thicker materials was the difficulty of obtaining a large enough initial primary grain size before secondary recrystallization. This was overcome by increasing the particle size of the silicon powder used. During the course of the work, it had been observed that the larger the grain size after sintering the more likely it was that the material would be successful in developing secondary crystals at a later stage. An experiment was therefore carried out to determine whether the material with the larger grain was more successful in developing secondary crystals due to the large grain produced at the sintering state per se or whether it was due to the greater reduction of silica brought about when the sintering temperature was raised in order to increase the grain size. A comparison was made between two compacts, one of which was made with silicon powder of 60 to 100 mesh, the other with silicon powder which was finer than 200 mesh. F?r this experiment, use was made of a phenomenon previously observed that the larger the particle size of the silicon powder employed in making a compact, the larger is the grain size of the compact. The silicon powder was ground

Jan 1, 1964

By P. K. Chatterjee

Computer aided design and inter active graphics have been well established in the electronics, automotive and mechanical engineering industries. The use of such aids in underground mine design and planning, however, has been noticeably absent. The large expense involved in the research and development of CAD and graphics systems and their highly specialized techniques have rendered investment in these areas difficult to justify. Optimum mine planning involves an interactive procedure of evaluation of several alternative plans. Generally the development of each mine plan of a given operation can take many man-months. This time constraint on planning precludes any comparative analysis and evaluation of alternatives, thereby introducing the possibility of unrealized gains. This paper outlines the development of a computer aided mine design program utilizing interactive graphics for the design, simulation and scheduling of underground coal mines. The program developed examines exploratory borehole information and produces a structured database of the sampled data. This database is utilized to generate seam sections and different mine layouts. A simulation of mine extraction and production levels and a schedule of proposed alternatives are then performed.

Jan 1, 1984

By Wei Zhang, Jinhong Zhang

An atomic force microscopy (AFM) image analysis has been applied to study in situ the adsorption of hydroxamic acid collector, i.e., octanohydroxamic acid (OHA), on malachite in aqueous solutions. AFM images show that hydroxamic acid collector adsorbs strongly on malachite mainly in the form of insoluble copper hydroxamate complex. Increasing the collectors’ concentration and the adsorption time both increase the adsorption of hydroxamic collectors on malachite. Results from the attenuated total reflectance–Fourier transform infrared spectrometry (ATR-FTIR) also show that the collector adsorbs strongly onto malachite, with strong absorbance spectra being detected, and the ATR-FTIR results confirm those as obtained by AFM. This specific adsorption mechanism explains that a high selectivity with a moderate collectivity will be achieved with a hydroxamic acid collector for the flotation of malachite. The findings of present study also show that AFM image analysis is a powerful tool for the study of the hydroxamic acid collectors’ adsorption on malachite surface and it can help with the development of novel collectors for malachite flotation.

Feb 1, 2025

"The Butte, Anaconda & Pacific railway extends from Butte to Anaconda. The electrification comprises 30 miles of main line single track, and includes sidings, yard and smelter tracks. When complete the electrified trackage will total about 90 miles on a single track basis.The traffic conditions are unusually severe as they consist principally of hauling copper ore from the Butte mines to the smelters at Anaconda, as well as hauling all the mine supplies, lumber, etc., in both directions; this traffic amounts to approximately 5,000,000 tons of freight per year. The maximum grade against the load is .3 per cent and the maximum train consists of 50 loaded steel ore cars, weighing 3,400 tons. .The locomotive units, two of which will be used for freight trains, weigh approximately 80 tons each. In addition to the freight business, there will be a certain amount of passenger traffic.The power for operating the Butte, Anaconda & Pacific railway is generated by, the Great Falls Power company, and is transmitted to the sub-stations at 100,000 volts. The synchronous motors are supplied with power at a potential of 2,300 volts, 60 cycles, 3-phase. Voltage regulators are installed in each sub¬station to secure the benefit of synchronous condenser effect of the motors.The passenger and freight locomotives are exactly similar, with the exception of the gearing.The roller pantograph mounted on the top of the cab is operated by air from the engineers position.The adoption of the 2,400-volt apparatus for so important a system, where the conditions of operation are so severe, is interesting of itself, as indicating the trend that future electrifications of importance may follow. A trolley potential of 2,400 volts was only adopted after a thorough investigation of other systems already in operation."

Jan 1, 1913

By H. Rush Spedden

R. T. Hukki has extended his study of ball mill grinding at supercritical speeds with an excellent mathematical analysis of tumbling mill grinding. When he speaks of supercritical speeds he is referring to the original Fahrenwald critical-speed formula. He said that, as an example of the use of supercritical speeds, if a fine grinding mill of any type is wet-grinding ore of 3.5 sp gr with steel balls at a certain conventional subcritical speed, the same power input and capacity should be obtainable with autogenous medium of 3.5 sp gr at a speed 100 to 120 pct of the critical in a grate- type mill of the same effective size. In addition, he introduced what he calls the base mill concept which, he stated, makes it possible to compare performances of mills of different sizes grinding with a metallic medium or with an autogenous medium of any specific gravity and at any speed. He showed the use of this concept and explained how it makes possible the evaluation of mill sizes and motors for any grinding purpose at any accuracy well within the conventional standards of design in milling practice. He further stated that the maximum capacity in pilot plant mills with various media, either metallic or autogenous, has always been found to be within the supercritical speed range. In his discussion of this paper he substantiated these findings with statements showing the increased capacity obtained in a milling plant in Finland which followed his principles.

Jan 7, 1960

By R. S. French, W. R. Hibbard

FOR tensile deformation, if the stress value is defined by the ratio of the load to the actual area, and the strain value by the natural logarithm of the ratio of the immediate length to the original gauge length of the sample, the resulting data when plotted with logarithmic coordinates result in a linear relation extending from the initial plastic yielding through the maximum load and in some cases, such as for copper and brass, to fracture&apos;.&apos;. The normal form of the curve, therefore, is a parabola, satisfying the following equation: S = Kem [1] where S and e represent true stress and strain, K is a constant, and m is a coefficient evaluating the slope of the curve and designated therefore as the strain hardening coefficient. Hollomon² has reported that this coefficient is a function of the yield strength as effected by grain size in alpha brass, and the carbon content and heat treatment of steel. In the case of steel, the value of the proportionality constant is a function of the carbon content. It was further shown in that paper2 and also by Low and Prater -hat, if the power relation between stress and strain remains valid, the strain hardening coefficient m, is equal to the strain at the maximum or necking load. Thus, an added significant feature is that this coefficient may serve as an index of the capacity for deformation prior to localized necking and subsequent fracture, e.g. drawability. The constant K may be defined as the strength of the material at unit strain. Together the K constant and the m coefficient describe an alloy&apos;s physical properties as far as strength and ductility are concerned for a particular yield strength and, in the case of steel, a particular carbon content. The work of Lacy and Gensamer4 gives data on alloy ferrites from which very close estimates of the strength of ternary and higher iron alloys have been made. It was the purpose of this investigation to develop similar data for commercial copper base alpha solid solution alloys. Preparation of Specimens Commercial binary alloys of copper with aluminum, beryllium, cadmium, nickel, silicon, tin and zinc were investigated. In addition, laboratory castings were made of a 1 pct silicon alloy and a 2 pct aluminum alloy to complete these particular series. Two types of copper were used, oxygen free OFHC and tough pitch FC. The analyses of these alloys are shown in table I. Standard ASTM sheet tensile specimens were used to determine the usual physical properties of each alloy and to obtain stress data at strains from 0.0005 to 0.01. Small (1/4 in. x 3 in. x tk.) samples

Jan 1, 1951

By W. Z. Choi

A combined size reduction- liberation model of grinding has been developed to predict the product size distribution for both free and locked particles. The model is an extension of the population balance model for size reduction. Locked (or composite) particles have been subdivided into discrete classes of different compositions to obtain more detailed information. The model has been tested on a sphalerite ore from Tennessee. Liberation data have been obtained using an areal scanning technique on microscope images of polished particle mounts.

Jan 1, 1985

By Emerson J

Drilling has always been one of the most important parts of the exploration process with most companies spending around 25% of their budget on drilling. Although superficially there appears to be little difference in drills and drilling practice a number of major refinements have taken place over the last decade that have significantly changed the drilling scene. One of the most important advances has been in hydraulic engineering giving rise to the Dual Purpose top drive drilling rigs. These have led to significant productivity increases with the high rotation speeds and longer fleets. Downhole technology has also advanced with better hammers, stronger drill rods, impregnated coring bits and improved drilling fluids. Although geologists continue to measure drilling performance on a cost per metre basis, greater consideration is at last being paid to the quality of sample produced. This is particularly the case with RC drilling where quite sophisticated automatic and semi automatic splitting devices have been developed. Drill operators are now required to be experienced in both Diamond coring and air drilling and be better qualified to maintain the more sophisticated machinery. Management of drilling companies or drilling divisions has also had to change to accommodate both the high capital cost of equipment and the demands of keeping drilling a cost effective exercise.

Jan 1, 1987

By G. Stephan Derrickson

Any type of agitation within a confined vessel is primarily concerned with two parameters: 1) A level of agitation describing the homogeneity of the constituents (whether it be suspension or mixing) and, 2) the energy efficiency with which this level of agitation is accomplished. The following is an attempt to present a solution to the problem of adequately defining and optimizing these properties. First included is a discussion of the application of good design practices to the determination of a mechanically efficient shape to the blade elements of the propeller. These practices, excluding several appropriate modifications, have been known, but not well understood, in aircraft fluid mechanics for a number of years. Secondly, having optimized the direct impartation of energy to the medium being agitated, attention is turned to one of the more perplexing phenomena of multi-phase systems - definition and prediction of agitation levels. The result of recent study and testing is a method of scaling which the authors feel provides a lucid understanding of governing physical parameters within the agitator itself, allowing one to scale up and down with confidence.

Jan 1, 1982

By Uwe Neis, K. Peter Kiefhaber

Whereas single particle flotation is considered to be evoked by physico-chemical bubble adhesion, floc flotation seems to be governed by other mechanisms. This study demonstrates that air bubble size does not affect the flotation efficiency of inorganic particles which have been destabilized by different means: 1. addition of simple salts and 2. polyelectrolyte dosage. The air-to-solids ratio A/S does not influence the solids removal efficiency within a broad range of examination. However, there is a significant difference between A/S-values necessary to obtain optimum flotation comparing both destabilization mechanisms. Polyelectrolyte concentration corresponding to complete particle destabilization at the isoelectric point leads to optimum sedimentation rates but not to optimum flotation efficiency. To obtain optimum solids removal by flotation higher polyelectrolyte concentrations are necessary resulting in a positive solids surface charge. These effects are explained on the basis of different floc structures.

Jan 1, 1980

By A. Bauer, P. Katsabanis, M. Baker

The principal results from a previous paper presented at the Mine Accident Prevention Association of Ontario in 1987 (1) are summarized here. It is concluded that the selection of explosives in mines experiencing sulphide ignitions is important and that aluminized explosives should be avoided because of their high explosion temperatures and their detonation products. The duration of the blast is also critical and secondary blasts should not occur simultaneously with nearby priroa:ty blasts.

May 11, 1988

By W. A. Mudge, Paul D. Merica

One of the most prominent features of our present-day industrial development is the ever-increasing demand put upon materials of construction. Engineering ingenuity, within the past 25 years, has been unusually active, and in some fields at least engineers frankly say that engineering design has progressed as far as the limitations imposed by the properties of the present materials of construction will permit. Consequently, they are today demanding improvement in their working materials and seeking new ones, through the aid of which the present limitations of design may be overcome. The activity of this search is evident in all fields, but it is particularly so in that of structural materials required to be resistant to corrosion. The corrosion resistance of metals and alloys is never absolute and all-inclusive; a particular alloy will withstand some corrosive conditions well and fail utterly under others. Furthermore, other properties, physical and mechanical, required in conjunction with corrosion resistance vary considerably for different commercial applications. One wants a soft, ductile sheet metal resistant to atmospheric corrosion; another, a high-strength alloy resistant to sulfuric acid. The last decade has witnessed active and definite progress in the development of high-strength, corrosion-resisting alloys. In June, 1924, a symposium by the American Society for Testing Materials, on Corrosion-resistant, Heat-resistant and Electrical-resistance Alloys, disclosed no less than 60 commercial alloys the properties of which were described as being suitable for industrial service where corrosion resistance was a feature. Today the number of these alloys has been doubled, at least. In addition, economy in design and construction through decreased weight has given considerable impetus to the improvement of alloys of which the mechanical propprties may be improved by heat-treatment.

Jan 1, 1935

By Paul D. Merica, W. A. Mudge

One of the most prominent features of our present-day industrial development is the ever-increasing demand put upon materials of construction. Engineering ingenuity, within the past 25 years, has been unusually active, and in some fields at least engineers frankly say that engineering design has progressed as far as the limitations imposed by the properties of the present materials of construction will permit. Consequently, they are today demanding improvement in their working materials and seeking new ones, through the aid of which the present limitations of design may be overcome. The activity of this search is evident in all fields, but it is particularly so in that of structural materials required to be resistant to corrosion. The corrosion resistance of metals and alloys is never absolute and all-inclusive; a particular alloy will withstand some corrosive conditions well and fail utterly under others. Furthermore, other properties, physical and mechanical, required in conjunction with corrosion resistance vary considerably for different commercial applications. One wants a soft, ductile sheet metal resistant to atmospheric corrosion; another, a high-strength alloy resistant to sulfuric acid. The last decade has witnessed active and definite progress in the development of high-strength, corrosion-resisting alloys. In June, 1924, a symposium by the American Society for Testing Materials, on Corrosion-resistant, Heat-resistant and Electrical-resistance Alloys, disclosed no less than 60 commercial alloys the properties of which were described as being suitable for industrial service where corrosion resistance was a feature. Today the number of these alloys has been doubled, at least. In addition, economy in design and construction through decreased weight has given considerable impetus to the improvement of alloys of which the mechanical propprties may be improved by heat-treatment.

Jan 1, 1935

By H. B. Pulsifer

ONE of the most common basic open-hearth furnace products is a simple carbon steel with a carbon range from 0.05 to 0.15 per cent. The material is widely used for sheets, tubes, bars, wire and the innumerable special objects of secondary fabrication. The properties of the material vary over wide ranges, depending on the more exact composition and details of manufacture or treatment that affect its structure. The present paper is a review of those properties and structures that have been found by studying this steel as used in the cap screw industry. At first glance this might be thought a narrow application of the steel, but, since the industry uses the material in the cold-worked, annealed and heat-treated conditions, the title of the paper may be excused for its comprehensiveness. Yet, in studying the wide ranges of properties and structures that preclude a more specific title, there can be no suggestion of completeness or finality. Even a summary of a few years&apos; work is no more than a preliminary survey of a field that will be fertile in scientific data and industrial products for many years to come. An outline of the structures will be given first, then a list of the previous contributions that are at hand and finally some details of the work and related problems, especially concerning this low-carbon steel in the surface-hardened condition.

Jan 1, 1931

By J. G. Kelly

"IntroductionOver the past twenty-five years of improvements to scooptrams In the Ontario Division of Inco Ltd., records indicate that on average, an 8 yard capacity machine at 80% availability will load, haul and dump about 100TPH from an average stoping area. This, essentially, means that Inco mines are limited to 2000 TPD as an approximate maximum production cap per minute. Some of the improvements made to scooptrams over this period have been:• dry disc and oil immersed brakes on larger loaders;• to replace air over hydraulic systems;• modulated shift transmissions;• greater breakout and tramming capacities by using larger engines and buckets;• operators&apos; compartments have been enlarged and better seats,• joystick controls and air-conditioned cabs have been utilized&apos;• major cost savings have been realized through tire maintenance improvements; and• major savings, safety improvements and increased ore recovery by using remote controls.After reciting the improvements listed above, and the list is by no means exhaustive, it is quite obvious that scooptrams are a mature product and that major design or performance improvements will not occur in the futre. Any futher improvements will be incremental in nature. Loading, hauling, and dumping with scooptrams is a batch process and as such is limited in its total output.Continuous Load/Crush/Convey Systems:In order to improve productivity, a radical new system was required. The target was 2000 tons per shift. In 1984, to meet the goal, Inco acquired the rights to a contiunous loader from Canadian Mine Services. Inco made modifications to the original prototype machine, such as: (I) conversion from rail mounted to crawlers for increased mobility; (2) a hydraulic cooling system was added; (3) flight bars were changed from cast to forged; (4) motor horsepower increased to 200 hp from 150 hp. Emerging from these modifications came a machine known as the CL-looo Oscilloader (Fig. 1).The CL-looo Oscilloader is an electric hydraulic 35-ton machine which is crawler mounted and has a drawbar pull of 30 tons. It has an adjustable frequency, oscillating lip which simulates the digging action of a manual .shovel. This action agitates and lifts the muckpile enough to allow it to settle by gravity onto the chain and flight conveyor table which then removes the ore to the tail end for discharge into either a crusher, a conveyor, a truck, or a combination of these.Late in 1985, six oscilloaders were fabricated and put into Inco mines for field trials. At Creighton Mine some early field trials were conducted with a rail mounted continuous loader loading directly into 140 cu.ft. Granby cars. Much of the field testing was in VRM drawpoints with the Oscilloader loading into 20-ton trucks or into Teletrams . At Levack Mine, by puttmg the truck on remote control, it was possible to have the operator run the Oscilloader and load his own truck (Fig. 2). At McCreedy West Mine, Copper Cliff North Mine, and Copper Cliff South Mine, the Oscilloaders discharged directly into 26-ton trucks."

Jan 1, 1988

By M. C. van Blerck

This paper reviews the current mining taxes in South Africa, discussing the recommendations of the Mantis Technical Committee, the measures already implemented, and the future outlook. It is concluded that the tax burden imposed on individuals and on the corporate sector should be reduced, and that the taxation of al economic sectors should be neutral. The reforms implemented in 1989 and 1990 are expected to continue, and it is thought that, if the State commits itself to tax neutrality and reduces the ordinary rate of company tax to 40 per cent, the rate of mining taxes will also be lower. Ring-fencing is expected to be reduced further and the rules for capital safe-havens to be refined.

Jan 1, 1990

By Karl L. Konnerth

THE rapidly increasing use of machinery for the mining of coal and operations incidental thereto has materially changed conditions from a safety standpoint. A few of the coal-producing states have recognized the need for specialized electrical equipment for use in mines and have introduced certain requirements in their State safety regulations, notably Pennsylvania. This paper discusses the principal problems involved in maintenance of such equipment. PERMISSIBLE: EQUIPMENT "Permissible" electrical equipment is equipment that has met certain prescribed standards for use in mines where hazardous conditions may occur and has been recommended by the U. S. Bureau of Mines. Such machinery is available on the market for most coal-mining operations--for instance, coal cutting, transportation, drilling, loading, working-place illumination, shot-firing and pumping. A notable exception is the trolley-reel gathering locomotive which, although its parts may be explosion-tested by the Bureau, has not been approved as permissible for the following reasons: I. The trailing cable is subjected to more severe service than on other equipment. 2. State regulations do not require that a working place be examined for methane before a locomotive enters it. 3. Even with two-conductor cable, imperfect or inadequate bonding may cause the emission of sparks at the wheels of the locomotive and at rail joints. 4. As the locomotive is equipped with a trolley pole, and as the trolley wire may be installed and used in unsafe territory in spite of rigid State regulations, a trolley-reel gathering locomotive is always a potential hazard. MAINTENANCE The proper procedure for maintenance of permissible equipment may be divided into three parts: (I) inspection, (2) actual maintenance and (3) changes or improvements to existing machines. To secure the fullest benefits through the use of permissible equipment it is necessary that all men involved understand the principles underlying the safety features of this equipment and realize the significance of defects, so that neglect and indifference in the maintenance thereof may be eliminated. Inspection From the standpoint of safety it is desirable no doubt to make a suitable inspection of permissible electrical equipment once a week, but the opening of every enclosed compartment at each inspection may do more harm than good. The openings to such compartments are closed with various types of covers very accurately machined, often made of the softer alloys to reduce weight, and fastened with a multitude of bolts, screws, washers, and other small parts. Frequent handling of these covers may cause sufficient damage to defeat their original purpose and intent.

Jan 1, 1941

By Robert W. Fullerton, Barry G. McMillan, Donald T. King, Henning E. Soderberg

INTRODUCTION Dust control in coal preparation and related transport is a multi- faceted problem which must be anticipated whenever dry, fine coal is subject to rough handling which can disperse it in the air. This problem can be minimized by careful planning and proper design, by eliminating procedures which maximize dust production, and by utilizing the most appropriate dust-collection "hardware" for a given situation. Proper maintenance after dust-collection systems are installed is also very important, and will not only enable the selected equipment to perform properly, but will also reduce component wear, recover valuable product with the highest efficiency, provide cleaner and safer working conditions, and allow local clean-air standards to be met. This chapter is designed to provide basic information about dust control in relation to material processing and handling during coal preparation. Areas discussed should provide the reader with insight into basic dust-collection theory, particle behavior, equipment types, ductwork and hood considerations, general maintenance and design planning, and the economics of dust collection. Because of the wide range of areas covered and the various specialized problems inherent in each, the text is organized to be a practical reference, and not a complete, unabridged treatise of ventilation and dust-control design. Nevertheless, the information presented should be of value in both understanding and reducing problems of dust control in coal preparation.

Jan 1, 1979

By A. Alonso, J. Daubenspeck

In the nickel extraction process at Nicaro, Cuba, dried and ground nickel bearing laterites are reduced at 1300-1400F in multiple-hearth furnaces. Nickel is leached from the reduced ore by aeration in an aqueous solution of ammonium carbonate. Nickel carbonate is precipitated from the liquor and calcined to yield nickel oxide. The following are the more important modifications of the Nicaro process since plant rehabilitation and expansion. Ten percent increase in tonnage was achieved without decreasing the fineness of the ore by minor mechanical modifications of the grinding plant. Another five percent increase in tonnage was attained by intentionally overloading the ore prepration and leaching circuits in an effort to control cobalt extraction. Modifications at the sintering plant allowed it to handle the entire output of the expanded plant. A fifty percent increase in leach liquor cooling facilities alone provided an increase in nickel production of five percent. Stronger fresh leach liquor for increased nickel washing efficiency was obtained through improved distribution of water to the ammonia absorption towers. Advantage was taken of the reduced calcine&apos;s capability to precipitate cobalt, and modifications in the leach liquor circulation provided controlled cobalt solubility with minimum harm to nickel extraction. Several process changes at the drying plant brought about a ten percent reduction in the fuel oil consumption at this pint. Controlled air addition to the reduction furnaces&apos; upper hearths burned formerly wasted combustibles thereby reducing oil consumption by twenty percent. The nickel extraction process successfully emplayed on the extensive but lowgrade lateritic ores of Eastern Cuba at the U. S. Government owned Nicaro plant, has been previously described in various publications. The large mine and plant operated by the Nickel Processing Corporation, located on the northeastern shore of Oriente Province, have been recently expanded to a yearly capacity of about 50 million pounds of nickel. Essentially, the operation involves open pit mining of a limonite-serpentine ore mixture containing 1.3 to 1.4 percent nickel and 34 to 38 percent iron. The comparatively lumpy, wet (25 to 30 percent moisture) ore is first dried and ground prior to chemical treatment, to which the entire 7,000 tons per day feed must be subjected. In the initial chemical action the dried and ground ore is reduced with carbon manoxide and hydrogen at 1300-1400° in multiple-hearth furnaces. The resulting metallic nickel is selectively leached from the reduced calcine by aeration in an

Jan 1, 1961

By David Ulrich Furrer

Materials and manufacturing processing technologies have played an important role in the development and capabilities of nearly all manmade products. Market drivers for fuel efficient, low cost, environmentally friendly, more capable transportation has given rise to significant materials challenges and subsequent developments. The rate of improvement and implementation of new commercial products can be limited by the rate of new materials and process technology development and qualification. As many materials are being designed for unique requirements and even location-specific unique properties, the implementation of tools and methods to enable rapid characterization and validation of material definitions and design systems must also be accelerated. A review of new integrated material, manufacturing process and component designs, engineering processes and emerging tools and methods will be discussed. The linkage of computational materials science and engineering into component design will also be discussed along with the challenges and opportunities for further growth and application of integrated computational materials engineering (ICME).

Jan 1, 2015