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By E. E. Carpenter

Believing that the results accomplished in the mill of the Churchill Milling Co., Wonder, Nev., during the fiscal year ended Sept. 30, 1914, will be of interest, I am presenting the more prominent facts and figures showing the progress made in treating this ore with especial reference to tonnage, supplies, costs, and extractions. The mill is situated at Wonder, Nev., in the Wonder mining district, 55 miles east from Fallon, Nev., the nearest railroad point. All supplies are hauled this distance by freight teams, this method of transportation having been found more reliable for continuous service than truclis, the price paid for hauling being slightly under one cent per pound. In this mill are treated the ores of the Nevada Wonder Mining Co. Ore is Unusually Hard The company which tested this ore before the mill was built reported "This ore is an unusually hard, tough, oxidized quartz, carrying a small percentage of high-grade sulphides, containing good values in both gold and silver. None of the rebellious silver minerals appear to occur in appreciable quantities." ... "In regard to the mill tonnage this ore is unusually hard and tough, and a high stamp duty cannot be expected. Using a 20-mesh screen and 1,050-lb. stamps, our best work was three tons per stamp per 24 hours." It is very probable that the ore delivered to the testing plant was harder than the regular mill run has proved to be. However, at present the mine is developed to a depth of 1,000 ft., and still shows hard ore in places at this depth in about the same proportion as on the upper levels from which the test ore came; during this year's work, ore was treated from nearly all levels. Together with this hard ore in the mill feed a considerable proportion appears to be broken down and tending to crumble, thus making an ideal mixture for stamp milling. A small proportion of talc is also noticeable, which sometimes increases in amount to the point where it is very troublesome in the thickeners.

Jan 1, 1916

By Douglas Bunting

In the anthracite fields of Pennsylvania, mine fires occur with more or less regularity and their existence is an ever-present hazard in coal mining. In all probability 90 per cent. of the mine fires can be ascribed directly or indirectly to the ordinary miner's open lamp. Other causes may be smoking, electrical installations, gas explosions, gas feeders, and the communication of fire to the outcrops from ash dumps, culm banks, timber and brush fires. Fires in pump rooms, engine rooms, and barns have been largely eliminated as a result of the Act of Assembly, approved June 15, 1911, which provides that all inside buildings, including engine rooms, pump rooms, barns, etc., shall be constructed of incombustible materials. Smoking of pipes, cigars, and cigarettes should be prohibited in the mines and too much care cannot be exercised in preventing fires by enforcing all rules designed for that purpose. Mine fires that involve underground fighting are invariably dangerous, and all fires, irrespective of the method pursued in extinguishing them, involve property loss and expense. Each fire generally presents a more or less original problem, dependent on the particular conditions. Generally mine fires may be divided into two classes: Those occurring in inaccessible workings and those occurring in accessible workings. The methods pursued in extinguishing or controlling mine fires are as follows: (I) direct attack, (2) smothering by sealing, (3) flushing with silt or other solids, (4) flooding with water, (5) cutting off, (6) surrounding with incombustible materials, (7) digging out by stripping from the surface. Most fires arc extinguished in their incipiency by direct attack and failure to extinguish by this method is due to late discovery, lack of water, and facilities for fighting, or improper procedure in the initial attack. Should the method first pursued be unsuccessful, careful consideration should be given in determining next the method to be adopted; then the work should be carried on as rapidly as possible and under the supervision of the most competent persons. Materials and supplies should be furnished without delay and in sufficient quantities for the work to be accomplished.

Jan 1, 1922

By Chester A. Fulton

In Polk County, Florida, the mining of raw phosphates began some 50 years ago with dredging operations on the Peace River, and in other near-by places by removal of shallow overburden with negroes and wheelbarrows, or with mules and scrapers, and the excavation and screening of deposits found close to the surface. There were many individual operations of comparatively short life. Later steam shovels removed the overburden, and still later hydraulic methods were substituted for the steam shovel. Within the last 10 years large electrically operated draglines have almost entirely replaced hydraulic mining for overburden removal. The matrix is still mined by hydraulic giants and pumped to the washer or recovery plant. The many small operations have long since disappeared and the most desirable phosphate lands have gradually been acquired through purchase or merger by the seven companies that are operating in the field today. These companies are producing and selling about 2,000,000 long tons of phosphate per annum, or about two-thirds of what the industry likes to think is the normal output, with 1929 and 1930 in mind. To produce these 2,000,000 long tons of raw phosphate, they mine and treat about 1,000,000 tons of tailings from older and less efficient operations, about 11,000,000 tons of matrix, and remove from above this matrix some 22,000,000 tons of overburden. The mining practice that has made possible the excavation and handling of 34 million tons of material to win but 2 million tons of merchantable product, selling for probably an average of only $4 per long ton when dried, should be of interest to the mining profession, though little has been written of it. The Florida Pebble Field, as it has come to be known, comprises an area (Fig. 1) within a radius of about 18 to 20 miles centering around Mulberry in Polk County, a small town 30 miles east of Tampa, Florida's largest port on the Gulf coast. The geology1 of these phosphate pebble deposits may be described briefly. A fairly pure limestone was altered to a secondary apatite.

Jan 1, 1938

By Chester A. Fulton

In Polk County, Florida, the mining of raw phosphates began some 50 years ago with dredging operations on the Peace River, and in other near-by places by removal of shallow overburden with negroes and wheelbarrows, or with mules and scrapers, and the excavation and screening of deposits found close to the surface. There were many individual operations of comparatively short life. Later steam shovels removed the overburden, and still later hydraulic methods were substituted for the steam shovel. Within the last 10 years large electrically operated draglines have almost entirely replaced hydraulic mining for overburden removal. The matrix is still mined by hydraulic giants and pumped to the washer or recovery plant. The many small operations have long since disappeared and the most desirable phosphate lands have gradually been acquired through purchase or merger by the seven companies that are operating in the field today. These companies are producing and selling about 2,000,000 long tons of phosphate per annum, or about two-thirds of what the industry likes to think is the normal output, with 1929 and 1930 in mind. To produce these 2,000,000 long tons of raw phosphate, they mine and treat about 1,000,000 tons of tailings from older and less efficient operations, about 11,000,000 tons of matrix, and remove from above this matrix some 22,000,000 tons of overburden. The mining practice that has made possible the excavation and handling of 34 million tons of material to win but 2 million tons of merchantable product, selling for probably an average of only $4 per long ton when dried, should be of interest to the mining profession, though little has been written of it. The Florida Pebble Field, as it has come to be known, comprises an area (Fig. 1) within a radius of about 18 to 20 miles centering around Mulberry in Polk County, a small town 30 miles east of Tampa, Florida's largest port on the Gulf coast. The geology1 of these phosphate pebble deposits may be described briefly. A fairly pure limestone was altered to a secondary apatite.

Jan 1, 1938

By T. B. Counselman

An iron blast furnace of 1000 tons daily capacity will produce a 100,000 cu. ft. per minute of blast-furnace gas. This contains a 25 per cent of carbon monoxide, and has a B.t.u. value of about 95. gas is used primarily for heating the stoves of the blast furnace, secondarily, under boilers, for steam production. Occasionally it is used in gas engines. The raw gas coming out of the furnace carries about 10 grains of dust per cubic foot of gas, under best operating conditions. With furnace "rolling" or slipping, this quantity may temporarily be gre increased. This dust would, of course, deposit on the checkers o: stoves, or plug the burners under the boilers; therefore the gas : be cleaned. Flow Sheet The first step in the cleaning operation, as shown by the flow s Fig. 1, is a dry dust catcher, of which there are several forms, partially cleaned gas next goes to a primary wet washer, where v sprays knock down most of the solid particles. If further cleani desired, the gas may then go to electrical precipitation. Again, the removed is collected in water. Dry dust catchers reduce the dust col from 10 grains to between 4 and 6 grains per cubic foot, and rec roughly half of the total flue dust in the gas. The wet washers rea most of the remaining dust, reducing the dust content to about 1/4 per cubic foot. Electrical precipitators, if used, further reduce the content to about 0.01 grain per cubic foot of gas. The flow sheet s the dust content of the gas at various steps in the treatment and als content of solids in the water. It should be noted that some plant less water on the primary wet washer than indicated, and that ofte solids content of the scrubber water will be 300 grains per gallon, or much higher. Reasons for Recovering Flue Dust.—There are two main incentive recovering flue dust from the scrubber water: (1) the value of the (2) stream or lake pollution, where such a reason applies.

Jan 1, 1937

By P. W. George

This paper presents geological data regarding deposits of over 7,500,000 tons of fine-grained sulphide ore in barite gangue. A series of pyroclastics and arkoses was intruded by sills of quartz porphyry in connection with batholithic intrusions of granite 3 miles from Buchans. Gentle folding, with fracturing and shearing of tuff beds and intruded quartz porphyry, accompanied and followed the intrusion of granite and porphyry. The sulphide-barite mineralization is localized primarily in fractured and sheared tuff beds, but also in the sheared quartz porphyry. Two structures have proved particularly favorable for mineralization-one, the center of an anticline; the other, a series of weak, incompetent tuff beds intruded by thin sills of quartz porphyry and located between strong beds of arkose. During the folding the weak tuff with intruded quartz porphyry was intensely sheared and contorted and subsequently mineralized by sulphides and barite. INTRODUCTION Buchans is 5 miles north of Red Indian Lake, in Central Newfound- land, at an elevation of 900 ft. above sea level and 400 ft. above Red Indian Lake, and is reached by a 37-mile private railway from Miller- town Junction. The first ore body found at Buchans was discovered some 30 years ago in the bed of Buchans River, by Matty Mitchell, an Indian woodsman employed by the Anglo-Newfoundland Development Co. Ltd. In the years following the discovery the ore was developed by shaft-sinking and drifting, with results indicating a lenticular ore body in a shear zone, containing about 100,000 tons of extremely fine-grained sulphide ore in barite gangue averaging about 0.05 oz. Au, 4 oz. Ag, 1.5 per cent Ch, 10 per cent Pb, 18 per cent Zn. Because a profitable metallurgical treatment for the ore was not found, the mine was closed down in 1911. In 1915, Mr. H. A. Guess, Vice President of the American Smelting & Refining Co., learned of the Buchans River ore body, and after metallurgical tests had been carried on from time to time in his company's testing plant a satisfactory separation of the sulphides by selective flotation was finally effected in 1925. Prospecting for additional ore bodies was begun in 1926, utilizing geophysical methods under the direction of Hans Lund-

Jan 1, 1937

By P. W. George

This paper presents geological data regarding deposits of over 7,500,000 tons of fine-grained sulphide ore in barite gangue. A series of pyroclastics and arkoses was intruded by sills of quartz porphyry in connection with batholithic intrusions of granite 3 miles from Buchans. Gentle folding, with fracturing and shearing of tuff beds and intruded quartz porphyry, accompanied and followed the intrusion of granite and porphyry. The sulphide-barite mineralization is localized primarily in fractured and sheared tuff beds, but also in the sheared quartz porphyry. Two structures have proved particularly favorable for mineralization—one, the center of an anticline; the other, a series of weak, incompetent tuff beds intruded by thin sills of quartz porphyry and located between strong beds of arkose. During the folding the weak tuff with intruded quartz porphyry was intensely sheared and contorted and subsequently mineralized by sulphides and barite. Introduction Buchans is 5 miles north of Red Indian Lake, in Central Newfoundland, at an elevation of 900 ft. above sea level and 400 ft. above Red Indian Lake, and is reached by a 37-mile private railway from Miller-town Junction. The first ore body found at Buchans was discovered some 30 years ago in the bed of Buchans River, by Matty Mitchell, an Indian woodsman employed by the Anglo-Newfoundland Development Co. Ltd. In the years following the discovery the ore was developed by shaft-sinking and drifting, with results indicating a lenticular ore body in a shear zone, containing about 100,000 tons of extremely fine-grained sulphide ore in barite gangue averaging about 0.05 oz. Au, 4 oz. Ag, 1.5 per cent Cu, 10 per cent Pb, 18 per cent Zn. Because a profitable metallurgical treatment for the ore was not found, the mine was closed down in 1911. In 1915, Mr. H. A. Guess, Vice President of the American Smelting & Refining Co., learned of the Buchans River ore body, and after metallurgical tests had been carried on from time to time in his company's testing plant a satisfactory separation of the sulphides by selective flotation was finally effected in 1925. Prospecting for additional ore bodies was begun in 1926, utilizing geophysical methods under the direction of Hans Lund-

Jan 1, 1937

By F. H. Wilson

Copper base alloys containing various amounts of aluminum and silicon are of considerable commercial interest. In particular the alloy containing 7 pct aluminum and 2 pet silicon shows an attractive combination of high strength with excellent, machinability. Since there is no evidence ill the literature that this ternary system has been studied since the recognition by Smith1 and Anderson2 in 1939 of the kappa phase of the binary copper-silicon system, the determination of the equilibrium phase relationships in the copper corner of the ternary diagram has been undertaken to provide a fundamental basis for understanding the behavior of these alloys. Phase boundaries have been determined by the micrographic examination of quenched samples while points on the liquidus surface have been obtained by thermal analysis. The results, of sufficient precision to serve their major purpose of providing a guide for the control of the manufacture of alloys in the region covered, are presented in a series of both isothermal and vertical sections of the diagram. Alloys StVdied For a rough survey of the copper corner of this ternary system the compositions listed in Table I (Series A) were employed. The results of examinations of these alloys indicated that the compositions listed in Table 2 (Series B) would further clarify regions of greater complexity. All alloys were prepared as 1200 g heats, the copper being melted under charcoal, and then first silicon and then aluminum were added. An excess of 0.05 pet silicon was allowed to cover deoxidation losses. Two small bars 5/8 by 1 1/4 by 5 1/4 in. were cast using Durville type casting equipment. Ailalyses were made on all alloys using material which was hot-rolled at 800 or 850°C and annealed 17 hr at 650°C. All analyses were found to be within 0.05 pet of the nominal composition. Since the precision of analysis is not much better than this, the points of both isothermal sections and vertical sections at fixed aluminum and silicon contents have been plotted at the compositions indicated by the nominal composition.

Jan 1, 1949

OF the many categories into which scientific knowledge has been arbitrarily 'divided, the one that has proved most. applicable in our attempts to gain an insight into the details of steelmaking processes is physical chemistry. To the young metallurgist who has only recently survived a college course in this subject, the application of its principles to reactions in liquid steel should not be difficult. The many excellent textbooks of physical chemistry provide ample material on the principles of this subject for the student of steelmaking processes. It is the purpose of this chapter to provide a concise review of the principles of physical chemistry that have proved useful in studies of steelmaking and at the same time to present some of the data that are essential to the application of physical chemistry to reactions at high temperatures. Certain parts of physical chemistry require rather formidable mathematics for their complete development, but in the main those applications in which we are here interested can be expressed in fairly simple terms. Many of the equations are logarithmic, and we shall use the symbols In X and log X to represent, respectively the natural and the common logarithm of X. The two are related-by In X = 2.303 log X. Logarithms may, be read from a good slide rule with sufficient accuracy for our purposes. In a few spots a knowledge of the calculus will be helpful. MATTER Innumerable forms of matter may, be recognized, and these may be converted by chemical processes into others, as ore, coke, and air are converted into iron, slag, and gas.. Whenever such a change occurs there is a corresponding change in the amount of energy associated with the matter. The process may require an input of energy, as in the electrolytic production of aluminum, or it may result in an output of energy, as in the combustion of fuel. The basic laws of the conservation of matter and of energy tell us that we cannot change the total amount of matter or the total amour t of energy.. When the fuel pile is used up, we realize that it has simply been converted into other forms of matter; .i.e., ash

Jan 1, 1964

By C. H. Wilson, J. W. Daly, J. J. Jakosky

Meteor Crater, Arizona, is a natural wonder which for years has been the subject of considerable discussion and study as to its origin and age (Fig. 1). Of the various theories advanced regarding the origin, two have been considered as most probable by a majority of investigators. The first theory is that the crater was formed by a meteorite or a swarm of meteoric material striking the earth at a high velocity and burying itself. The second theory is that the crater was formed by a "steam explosion" from hot solutions or gases coming from underneath the present sedimentary beds which overlie the area. In order to obtain more detailed information regarding the conditions existing at the crater, the present management decided to have a detailed geophysical examination made. The origin of the crater is of considerable scientific importance and interest. More or less active mining operations have been carried out during the past 20 years by various groups who believed that the crater was of meteoric origin, and who hoped that sufficient quantities of such material had been buried to be commercially valuable. Fragments of meteoric material found on the surface of the ground in the debris around the rim gave analysis of approximately 92 per cent iron and 8 per cent nickel, with some platinum and iridium. The material having a gross value of approximately $50 per ton, mining would be commercially profitable if sufficient quantities of the material existed in condition for mining. In the early work numerous drill holes and shallow shafts were put down, mainly in the northern portion of the crater. Pulverized material and debris caused considerable difficulty, and in an effort to overcome this the present management started a 1500-ft., two-compartment shaft on the south rim of the crater and outside of the fill zone. The intention was to sink the shaft in the solid rock outside of the crater, and then to crosscut toward the crater at a depth of 1500 ft. The work was finally stopped when a depth of 650 ft. was reached, because water poured into the shaft through large cracks and fissures in the rock. The enormous force responsible for the crater had also broken

Jan 1, 1932

By Harry V. Welch

This paper presents a brief discussion of numerous devices and processes which have been utilized for the recovery of values from gases in copper reduction works and describes in greater detail the development and application in recent years of electrical precipitation, more familiarly known as the Cottrell process, to the problems of dust losses with furnace gases in copper-smelting and refining plants. The field for collection of suspended particles in gases is widely extended in our modern complex, congested .and industrialized mode of living, and its satisfactory solution is required by our increasing appreciation of the extravagant waste, unhealthful effects and nuisance which such uncontrolled emission of solid suspensions represents. Much of the special dust-recovery equipment in use today has been developed in one industry and carried over to many others. The early work of Cottrell was with sulfuric acid mists, aimed at the purification problem in contact acid manufacture, but the present uses of Cottrell equipment cover a diversified field—carbon black, combustible gas, oil mists, iron blastfurnace fumes and dusts, cement-kiln gases, as well as the purification of gases in contact and chamber acid plants and its wide and extended use in the nonferrous metallurgical field of copper, zinc and lead, and their associated metals. Dust and fume collection from furnace gases became a problem only with the modern development of large and amply powered auxiliary furnace equipment, which in turn permitted large furnace units, fast driving and large outputs of finished product per unit of furnace capacity. The ancient metallurgist with his small clay pot and hand-operated bellows had too little gas velocity to cause a real dust loss. As furnaces grew in size, flues and stacks were added, and undoubtedly the first observable dust losses were indicated by the deposits in the flue and stack base. Large flues, it was noted, collected more than smaller ones, and the expansion of a portion of the flue into a chamber represented the first serious attempt at recovery of furnace dust losses. For a century or more the settling chamber represented the best of skilled metallurgical practice in recovery of furnace dust, and it may be said to have reached

Jan 1, 1934

By Cecil Hagen

All of the production for Ecuador during 1940 came from the Santa Elena Peninsula, Province of Guayas; the major portion coming from the Ancon field, which is controlled mostly by Anglo-Ecuadorian Oilfields, Ltd. A small amount was produced from the shallow pumpers and pozos, or oil pits, at Cautivo-Achallan, Carolina, Santa Paula, Concepcion, El Tambo and Mina Tigre. Considerable exploration was carried on in the country during 1940 and numerous concessions were in force, as shown by the accompanyiag map. Anglo-Saxon continued its exploratory work in the Oriente by surface geological methods and some geophysical surveys. It is understood that this concern did considerable airplane mapping. International Petroleum, on its large concessions between the Andes and Pacific Coast, did considerable surface work as well as some geophysical. No exploratory test wells were drilled by either of these

Jan 1, 1941

By Cecil Hagen

All of the production for Ecuador during 1940 came from the Santa Elena Peninsula, Province of Guayas; the major portion coming from the Ancon field, which is controlled mostly by Anglo-Ecuadorian Oilfields, Ltd. A small amount was produced from the shallow pumpers and pozos, or oil pits, at Cautivo-Achallan, Carolina, Santa Paula, Concepcion, El Tambo and Mina Tigre. Considerable exploration was carried on in the country during 1940 and numerous concessions were in force, as shown by the accompanyiag map. Anglo-Saxon continued its exploratory work in the Oriente by surface geological methods and some geophysical surveys. It is understood that this concern did considerable airplane mapping. International Petroleum, on its large concessions between the Andes and Pacific Coast, did considerable surface work as well as some geophysical. No exploratory test wells were drilled by either of these

Jan 1, 1941

By A. W. Ashbrook

The constraints which are being imposed on metallurgical operations in respect to the environment and worker hygiene are having a substantial influence on the various processes which are being studied and developed for future use. The unit process of solvent extraction can be no exception. It is therefore vital that sufficient be known about the effects of a solvent extraction process in terms of its environmental and hygiene impacts before the process gets to the construct- ion stage. The purpose of this section is to bring these matters to the readers' attention, and to indicate, albeit briefly, some of the problems, and what we know about the effects, of SX processes from an ecological point of view. Hydrocarbons Petroleum hydrocarbons are bio-degraded to form C02; several factors may limit the rate of bio-degradation, which are as follows:

Jan 1, 1978

By Edwin Chance

EDWARD H. Coxe, Knoxville, Tenn. (communication to the Secretary*).-Mr. Chance has omitted to mention one very important use for the chemist in connection with the preparation of coal, and that is in connection with coal washing. Efficient coal washing, and especially of the finer sizes, can be accomplished only under the supervision of a chemist, as the proper regulation of the washer can only be had by frequent sampling and analysis of the raw and washed product and the refuse, say at least semi-weekly; and only in this way can a check be kept on the quality of the product and the amount of good coal wasted in the refuse. In large operations, frequently enough coal can be saved from going to the refuse pile to more than pay the salary of the chemist.

Jan 12, 1916

October Meeting of the Institute.-Invitations have been sent to the members of the following societies through the respective Secretaries to attend the October meeting of the Institute and the Dinner which will be given on the evening of Oct. 17 : American Society for Testing Materials, American Iron and Steel Institute, American Society of Mechanical Engineers, American Society. of Civil Engineers, American Institute of Electrical Engineers, . American Foundry men's Association. Members of these Societies have also been invited to contribute to the discussion of the various papers to be presented at the meeting, a revised list of which appears in the notes of the Iron and Steel Committee on p. vi. Many individuals of national and international prominence have also been invited to contribute discussions of these papers, and the response to these invitations has been extremely encouraging.

Jan 9, 1913

The first practical and successful use of a laser-beam guidance system for a tunnel machine drilling to a remote target has been achieved at the Bureau of Reclamation's Navajo Indian Irrigation Project near Farmington, N. Mex. Using such a guidance system, the Hughes Tool Co.'s "Betti I" drilled a 10,000-ft long tunnel in eight months and 18 days to within 5/8-in, of established line and grade. The electronic system which guided the "Betti I" features a gas laser whose beam is aimed at two light-sensitive targets on the boring machine. From these targets, the operator of the machine receives electric signals on a read-out panel which tell him the machine's precise location within the tunnel. The operator can then make any adjustments necessary to maintain line and grade while drilling ahead.

Jan 6, 1966

By Eugene P. Pfleider, Jared Scofield

During the past ten years, the trend on the Mesabi Range has been toward the establishment of integrated operations which mine, concentrate, and pelletize the large reserves of magnetic taconite. However, since the supply of open-pit ores of acceptable quality is by no means inexhaustible, it has been proposed that it be supplemented by developing the magnetic taconites that extend down dip past the economic limits for open-pit methods. In Phase I of a long range study, Pfleider and Yardley1 collected information on the general character of the Mesabi iron formation at depth and proposed that an underground lane-and-pillar mining system be considered to extract those high grade layers where they might exist over a considerably areal extent. An approximate cost estimate was included initially, with the thought of later developing a feasibility study as time permitted.

Jan 9, 1967

By Ronald L. Longwell

PROPERTY LOCATION Located in the Copper Creek area of the Galiuro Mountains, the Old Reliable is on ground first claimed for mineral value during the Civil War. The deposit was mined sporatically from 1880 to 1919 and again in 1953 and 1954, with a total of about 30,000 tons of ore removed. The ore body is a near vertical breccia pipe containing approximately 4,000,000 tons of 0.80% copper with mineralization occuring as chalcocite, chalcopyrite, malachite, chalcanthite, and chrysocolla. The host rocks are extrusive lavas of cretaceous age which were intruded and mineralized by Copper Creek Granodiorite, which is Laramide in age. The ore zone, which occurs on the toe of a ridge, is about 300 feet by 600 feet in plan, with the bulk of the deposit extending from the surface to a depth of 500 feet.

Jan 1, 1974

By Donald C. Myntti

Modern open-pit mining can be described as a capital-, labor-and energy-intensive, large-scale, mechanized, and highly repetitive bulk material preparation and handling operation, with emphasis on the word "mechanized." In hard rock, this generally means shovels loading blasted materials into haulage units for transport to processing plants, stockpiles, or waste dumps. Mine management deals with several primary concerns on a daily basis; e.g.: Will any serious accidents and labor problems occur today, and will the tonnage targets be met considering the physical condition of the equipment? The latter subject will be discussed from a maintenance perspective. A successful, progressive heavy equipment maintenance program that protects company assets involves many elements. They include: •Proper equipment selection and procurement •Well-trained and motivated workforce •Good shop facilities •Preventive maintenance (PM) program •Warehouse support •Operations-maintenance department cooperation •Meaningful paperwork

Jan 3, 1978