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By H. H. Stoek

A study of Americarf coal-mine practice shows two of its distinctive features to be: A greater number of accidents per thousand employees than in any of the other leading coal-producing countries; a much greater percentage of the coal lost than in any of the other leading coal-producing countries. Although our subject is mainly concerned with the second feature, any consideration of mining methods should include safety, efficiency, and economy or costs. If the argument could be offered that our wasteful mining was necessary on account of safety, and that it is carried out with less loss of life than in other countries, the plea for conservation of coal could not he so strongly urged. But when we are wasteful of both life and property, the subject merits more: consideration than it has received. Some coal operators will doubtless say that the unit of accidents should be the number per million tons produced rather than per thousand employees, for by adopting this unit America probably stands in the lead rather than the lowest among the countries. However, vital statistics are not usually so expressed by other governments, by life and accident insurance companies, or in other industries, and it is merely begging the question and attempting to bolster up a bad condition to adopt a peculiar unit for the statement of our accidents. For many years the statement was made by various agencies, and was unchallenged, that "For every ton of bituminous coal mined in the United States a ton had been lost in the way of pillars left in the mines." This statement was undoubtedly true for many years, and although in the past decade some progress has been made toward obtaining a higher extraction, and in some districts very decided progress, the loss is still great; and, although no exact data can be given, it is probable that for the United States as a whole at least one ton is lost for every two mined.

Jan 1, 1923

By H. H. Stoek

A study of Americarf coal-mine practice shows two of its distinctive features to be: A greater number of accidents per thousand employees than in any of the other leading coal-producing countries; a much greater percentage of the coal lost than in any of the other leading coal-producing countries. Although our subject is mainly concerned with the second feature, any consideration of mining methods should include safety, efficiency, and economy or costs. If the argument could be offered that our wasteful mining was necessary on account of safety, and that it is carried out with less loss of life than in other countries, the plea for conservation of coal could not he so strongly urged. But when we are wasteful of both life and property, the subject merits more: consideration than it has received. Some coal operators will doubtless say that the unit of accidents should be the number per million tons produced rather than per thousand employees, for by adopting this unit America probably stands in the lead rather than the lowest among the countries. However, vital statistics are not usually so expressed by other governments, by life and accident insurance companies, or in other industries, and it is merely begging the question and attempting to bolster up a bad condition to adopt a peculiar unit for the statement of our accidents. For many years the statement was made by various agencies, and was unchallenged, that "For every ton of bituminous coal mined in the United States a ton had been lost in the way of pillars left in the mines." This statement was undoubtedly true for many years, and although in the past decade some progress has been made toward obtaining a higher extraction, and in some districts very decided progress, the loss is still great; and, although no exact data can be given, it is probable that for the United States as a whole at least one ton is lost for every two mined.

Jan 1, 1923

By W. Petruk, R. S. Boorman, R. Gilders

Approximately 33% of the silver in the Zn-Pb-Cu-Ag ore of Brunswick Mining and Smelting Corporation Limited is lost to the tailings and an additional 11% to the zinc concentrate for which no payment is received. 38% to 44% of this lost silver is carried by tetrahedrite, 28% by galena and 28% to 34% by a third silver carrier. The silver minerals acanthite and pyrargyrite have been identified in mill products and hence these are suggested as the principal third silver carrier(s) accounting for 13 to 20% of the silver in Brunswick ore. About 24% of this third silver carrier assemblage is lost to the zinc concentrate and 52% to concentrator tailings.

Jan 1, 1984

By John W. King

Uranium ore was first discovered in the Edgemont district of the southern Black Hills in the summer of 1951. The discovery was not made known for some time, but after the news leaked out prospecting became intense, and several hundred claims were staked in the spring of 1952. The Hot Springs Sub Office of the Atomic Energy Commission was established at that time and airborne radiometric surveys were commenced by the Government and by private companies. During the succeeding summer another important discovery was made by private airborne surveys in the northern Black Hills, and the area favorable for uranium ore was expanded many times. Between that summer of 1952 and the present, many individuals and groups have explored, developed, and exploited their claims until now uranium ore is produced in significant quantities and substantial reserves have been developed. The Black Hills portion of the geologic map of the U. S. issued by the U. S. Geological Survey is shown in Fig. 1. Sedimentary formations are exposed as a series of cuestas and hogbacks in a roughly annular pattern with the older sediments resting on the pre-Cambrian core, which is exposed in the eastern and southern portions of the dome.

Jan 1, 1956

By William H. Spice

For the year 1943, exploratory drilling in South Central Texas continued on the sharp decline that started during 1942. Of the 3 counties comprising this district, as now revised to include the same area as is covered by District No. I, Oil and Gas Division, Railroad Commission of Texas, I5 counties are producing oil or gas. Only 29 exploratory wells were drilled during 1943, as compared with 51 exploratory wells in 1942, or a decrease of over 40 per cent. One new oil field and one new gas field were discovered during the year and a new horizon was discovered in an existing oil field. This cornpares with two new oil fields and an extension to an existing gas field in 1942. The one new oil field, South Washburn, in southeastern La Salle County, was discovered by Quintana Petroleum Corporation's No. I-D South Texas indicate in April 1943, flowing 4 bbl. per day, 48" A.P.I. gravity oil with an estimated 4 million cubic feet of gas from Wilcox sand at 6030 ft. This well i's the result of an extensive seismograph survey of the area. It is about 434 miles southwest of the same company's Green Branch field and by the end of the year one dry hole had been drilled to the southwest of this discovery. The one new gas field, which was not named, was located in eastern McMullen County by Edwin M. Jones' No. 102 Ezzell, in November 1943, for an estimated 8 million cubic feet of gas from shallow Jackson sand at 1222 ft. NO addi- tional wells have been drilled in this area, which may also be considered as an extension to the South Calliham field. The one new producing horizon was discovered in the South Campana field in southeastern McMullen County, by Argo Oil Corporation's No. 2-G Edrington, in January 1943, flowing 55 bbl. per day, 21' A.P.I. gravity oil with 40 per cent water from Government wells sand at 2609 feet. None of these discoveries were of major importance and subsequent development in these new areas has proved to be disappointing. Produc'tion for the district during 1943 totaled approximately 6,985,000 bbl. from about 3430 producing wells. This is an increase in production of about 5 per cent over 1942, but a decrease in producing wells of about 10 per cent under the number of wells producing in 1942 for the same district. Average production per well was 5.4 bbl. during 1943 as against 4.8 bbl. during 1942. Approximately 5,320,000 hhl. of this total production, or 76 per cent, was produced by the four Edwards lime fields, Luling, Branyon, Salt Flat, and Darst Creek, which are from 22 to 14 years old. The remaining production came from the 43 other active oil fields in the district. Drilling in the proven fields maintained approximately the same level as for 1942, with a total of 36 wells drilled. Of these operations, 21 were oil wells, one was a gas well and 14 were dry holes. This is a slightly better proportion of producers than for 1942. Washburn field had the greatest number of new producing wells drilled during the year, with a total of 10.

Jan 1, 1944

By William H. Spice

For the year 1943, exploratory drilling in South Central Texas continued on the sharp decline that started during 1942. Of the 3 counties comprising this district, as now revised to include the same area as is covered by District No. I, Oil and Gas Division, Railroad Commission of Texas, I5 counties are producing oil or gas. Only 29 exploratory wells were drilled during 1943, as compared with 51 exploratory wells in 1942, or a decrease of over 40 per cent. One new oil field and one new gas field were discovered during the year and a new horizon was discovered in an existing oil field. This cornpares with two new oil fields and an extension to an existing gas field in 1942. The one new oil field, South Washburn, in southeastern La Salle County, was discovered by Quintana Petroleum Corporation's No. I-D South Texas indicate in April 1943, flowing 4 bbl. per day, 48" A.P.I. gravity oil with an estimated 4 million cubic feet of gas from Wilcox sand at 6030 ft. This well i's the result of an extensive seismograph survey of the area. It is about 434 miles southwest of the same company's Green Branch field and by the end of the year one dry hole had been drilled to the southwest of this discovery. The one new gas field, which was not named, was located in eastern McMullen County by Edwin M. Jones' No. 102 Ezzell, in November 1943, for an estimated 8 million cubic feet of gas from shallow Jackson sand at 1222 ft. NO addi- tional wells have been drilled in this area, which may also be considered as an extension to the South Calliham field. The one new producing horizon was discovered in the South Campana field in southeastern McMullen County, by Argo Oil Corporation's No. 2-G Edrington, in January 1943, flowing 55 bbl. per day, 21' A.P.I. gravity oil with 40 per cent water from Government wells sand at 2609 feet. None of these discoveries were of major importance and subsequent development in these new areas has proved to be disappointing. Produc'tion for the district during 1943 totaled approximately 6,985,000 bbl. from about 3430 producing wells. This is an increase in production of about 5 per cent over 1942, but a decrease in producing wells of about 10 per cent under the number of wells producing in 1942 for the same district. Average production per well was 5.4 bbl. during 1943 as against 4.8 bbl. during 1942. Approximately 5,320,000 hhl. of this total production, or 76 per cent, was produced by the four Edwards lime fields, Luling, Branyon, Salt Flat, and Darst Creek, which are from 22 to 14 years old. The remaining production came from the 43 other active oil fields in the district. Drilling in the proven fields maintained approximately the same level as for 1942, with a total of 36 wells drilled. Of these operations, 21 were oil wells, one was a gas well and 14 were dry holes. This is a slightly better proportion of producers than for 1942. Washburn field had the greatest number of new producing wells drilled during the year, with a total of 10.

Jan 1, 1944

By Warren B. Weeks

The year 1940 saw an increase of 20 per cent in oil production over the previous year—compared with a 16 per cent increase the previous year. In all, 25,790,380 bbl. were produced, an increase of 4,414,150 bbl, over 1939 and the largest production figure for south Arkansas since 1928. The older settled production continued to decline. Magnolia accounted for most of the increase, with aid from the other recent deep fields. During the year, 169 wells were drilled, 79 fewer than in the previous year. Of 131 wells drilled in proven fields, 18 were dry. Three of the 38 wildcats were pool openers. The drilling depth record was increased from 9028 to 9550 feet. Trend of Prospecting For the first time since 1936, the search for oil in the deep Smackover limestone slackened perceptibly; g dry wildcats ended in Smackover, 2 in. the underlying Eagle Mills; 7 penetrated Paleozoic beds, while 9 ended in Hosston, 2 in Glen Rose, 2 in Paluxy and 4 in Gulf. Geology The wells listed in Table 2 either resulted in the discovery of new oil pools or, because of their depth or location, afforded impor-tant stratigraphic or structural informa-tion. Fig. I is a general columnar and stratigraphic section showing the relation-ship of the strata within the Comanche series. The nomenclature shown was ac-cepted by the Shreveport Geological Society. It was subsequently published by Imlay,l who indicated probable correlations with other areas and presented evidence for the possible Jurassic age of the under-lying Cotton Valley and Smackover formations. New Fields Pouke.—On June 10, 1940, the Louark Producing Co. completed its No. I Sturgis, sec. I, T. 17 S., R. 27 W., in central Miller County, producing between 3583 and 3607 ft. in the upper part of the Paluxy forma-tion. The well flowed I00 bbl. of 3r.4' gravity oil per day through Ns-in. tubing choke. This discovery resulted from seismograph work. Six other wells were drilled in the area, none of which found production in the original sand. One of these wells is producing from a sand 50 ft. deeper in the section. The others were abandoned. No further development is in prospect. Production is from lenticular sands of the upper Paluxy; 45,556 bbl. had been pro-duced by the end of 1940. There is structural closure against a fault to the northwest. McKanzie.—The Atlantic Refining Com-pany's No. I Bodcaw Lumber Co., sec. 29, T. 17 S., R. 23 W., eastern central La-fayette County, was completed June 8, 1940, as the eighth and farthest west of the Smackover (Reynolds o6lite) limestone pools. The well flowed 10 bbl. an hour of 58.6' gravity distillate through an 1 1/64 Ma-in. tubing choke, with a gas-oil ratio of 8400:I.

Jan 1, 1941

By Warren B. Weeks

The year 1940 saw an increase of 20 per cent in oil production over the previous year—compared with a 16 per cent increase the previous year. In all, 25,790,380 bbl. were produced, an increase of 4,414,150 bbl, over 1939 and the largest production figure for south Arkansas since 1928. The older settled production continued to decline. Magnolia accounted for most of the increase, with aid from the other recent deep fields. During the year, 169 wells were drilled, 79 fewer than in the previous year. Of 131 wells drilled in proven fields, 18 were dry. Three of the 38 wildcats were pool openers. The drilling depth record was increased from 9028 to 9550 feet. Trend of Prospecting For the first time since 1936, the search for oil in the deep Smackover limestone slackened perceptibly; g dry wildcats ended in Smackover, 2 in. the underlying Eagle Mills; 7 penetrated Paleozoic beds, while 9 ended in Hosston, 2 in Glen Rose, 2 in Paluxy and 4 in Gulf. Geology The wells listed in Table 2 either resulted in the discovery of new oil pools or, because of their depth or location, afforded impor-tant stratigraphic or structural informa-tion. Fig. I is a general columnar and stratigraphic section showing the relation-ship of the strata within the Comanche series. The nomenclature shown was ac-cepted by the Shreveport Geological Society. It was subsequently published by Imlay,l who indicated probable correlations with other areas and presented evidence for the possible Jurassic age of the under-lying Cotton Valley and Smackover formations. New Fields Pouke.—On June 10, 1940, the Louark Producing Co. completed its No. I Sturgis, sec. I, T. 17 S., R. 27 W., in central Miller County, producing between 3583 and 3607 ft. in the upper part of the Paluxy forma-tion. The well flowed I00 bbl. of 3r.4' gravity oil per day through Ns-in. tubing choke. This discovery resulted from seismograph work. Six other wells were drilled in the area, none of which found production in the original sand. One of these wells is producing from a sand 50 ft. deeper in the section. The others were abandoned. No further development is in prospect. Production is from lenticular sands of the upper Paluxy; 45,556 bbl. had been pro-duced by the end of 1940. There is structural closure against a fault to the northwest. McKanzie.—The Atlantic Refining Com-pany's No. I Bodcaw Lumber Co., sec. 29, T. 17 S., R. 23 W., eastern central La-fayette County, was completed June 8, 1940, as the eighth and farthest west of the Smackover (Reynolds o6lite) limestone pools. The well flowed 10 bbl. an hour of 58.6' gravity distillate through an 1 1/64 Ma-in. tubing choke, with a gas-oil ratio of 8400:I.

Jan 1, 1941

By W. M. Courtis

THIS district commences near Pigeon River, the northeastern boundary between Minnesota and Province of Ontario, and extends entirely around the north shore of Lake Superior, terminating for the present at the Bruce Mines on Lake Huron. The discoveries of mineral-bearing veins have been confined for the most part to the lake shore, or to the country opened up by the Dawson Red River road. As yet the country back from the lake has been but little explored, on account of its roughness, being intersected by steep, rocky trap bluffs, 1000 or more feet high, and alternating white cedar and tamarack swamps. The forests are exceedingly difficult for prospectors. In many places Titanic piles of rocks, protected by chevaux-de frise of dead cedars, with their hooked, tough, sharp branches, and- a covering of spongy moss, sometimes several feet thick, successively guard against the discovery of hidden treasure. The Hudson's Bay Company for nearly a century have maintained trading-posts at Fort William and other points, which probably opened the way to the first discoveries that were made at Prince's Bay, near the western limit of the district. At this point a large vein was worked by Colonel Prince, the owner, as early as 1846. The richest part of the vein seems to have been on Spar Island, but work was stopped on account of excess of water. Sir William Logan states that a mass of ore weighing several hundred pounds and carrying 3 per cent. of silver was taken out. On the mainland small quantities of native and sulphide of silver were found, together with iron and copper pyrites, zinc blende, and galena, in a large spar vein. On the main shore a drift 165 feet long and 90 feet in depth

Jan 1, 1877

By B. C. Johnson, K. L. Sublette, F. L. Prestridge

A problem common to the petroleum and mining industries is the resolution into its component phases of mixtures composed of a polar liquid dispersed in an immiscible, continuous nonpolar liquid. In the petroleum industry the polar liquid is water or brine and the nonpolar liquid is crude oil. The source of the entrained aqueous phase is connate water and/or condensed steam used in secondary and tertiary recovery methods. In the mining industry dispersions of polar liquids in immiscible, nonpolar liquids are created in solvent extraction (SX) systems. In these systems the polar, dispersed liquid is leachate or stripping solution while the nonpolar, continuous liquid is the extraction solvent.

Jan 1, 1984

By J. B. Cohen, B. W. Howlett, M. B. Bever

The partial molar heats of solution at infinite dilution in tin of aluminum at 300° and 350°C and of gallium, indium, and thallium at 240°, 300°, and 350°C have been measured by tin solution calori-metry. Aluminum, gallium, and thallium are endo-thermic on solution; indium is exothermic. Any temperature dependence of the heats of solution lies within the experimental scatter. Over the dilute ranges investigated, only aluminum has a measurable change in its heat of solution with composition. HEATS of solution of one element in another reflect the interaction between them. The investigation of partial molar heats of solution in dilute alloys is of particular interest as the properties of the solvent are altered to only a limited extent by the presence of the solute and also as the interaction between solute atoms is small. When the heats of solution of a related series of elements in a solvent are known, a systematic comparison may be made. In the investigation reported here, the partial molar heats of solution of the Group III elements aluminum, gallium, indium, and thallium in dilute solution in tin were measured. This work follows an investigation of the heats of solution in tin of the Group IB elements.' EXPERIMENTAL PROCEDURES Materials. Samples of gallium, indium, and thallium were obtained from Johnson, Mathey and Co., Ltd. Indium and thallium were supplied as wire, 1.6 mm in diam; gallium was in the form of irregular pieces. The supplier reported the following minimum purities: gallium—99.95 pct; indium—99.99 pct; thallium—99.99 pct. The aluminum, obtained from Alcoa Research Laboratories, was reported to be 99.995 pct pure. The tin was supplied by Baker and Co., Inc.; the reported analysis indicated a tin content of at least 99.96 pct with lead as principal impurity. Calorimeter. this description will cover only the essential features of the calorimeter with special attention to modifications made since an earlier description was published.' A Dewar flask containing the tin bath was held in a constant-temperature bath of a near-eutectic mixture of lithium, sodium, and potassium nitrates. This bath, which was stirred vigorously, was heated by a primary resistance winding in the container wall and by a secondary winding immersed in the salt. The voltage supplied to both windings was stabilized. The temperature of the salt bath was controlled by means of a platinum resistance thermometer in one arm of a Wheatstone bridge. The light from a mirror galvanometer in the bridge circuit fell on a photocell which controlled the current in a saturable reactor in series with the secondary winding. In this manner, the temperature of the salt bath was controlled to ±0.003°C and that of the tin bath to at least ±0.002°C. Each of these temperatures was measured by two iron-constantan thermocouples in series, coiled in a helix to minimize heat loss and immersed in the salt and tin baths in protective sheaths. The temperature of the laboratory was kept constant to ± 1°C during a run. Specimens were dropped into the tin bath from an addition arm held at O°C which was part of the cal-orimetric system. The system was evacuated to about 0.02 1 to minimize oxidation and to reduce transfer of heat. The bath was stirred by a glass stirrer introduced through a double Wilson seal. The samples were scraped clean before weighing, which was carried out as rapidly as possible. Each sample was immediately placed in the evacuated addition arm to minimize contamination. These precautions were especially necessary with aluminum. After the runs with gallium and thallium at all temperatures and with indium at 240° and 350°C (Series I) were completed and before the runs with indium at 300°C and aluminum at 300° and 350°C (Series 11) were begun the following changes were made. The shape of the Dewar flask was changed so as to result in a lower surface to volume ratio of the bath and at the same time the amount of tin was reduced from 500 to 400 g. The paddle type stirrer was replaced by a helical screw and the rate of stirring was increased to about 150 to 200 rpm.

Jan 1, 1962

By W. M. Gray

The determination of the state of stress existing at a point in any solid body requires the determination of the six components of the stress tensor relative to a convenient set of axes. One general method of doing this in rock is to make strain or deformation measurements associated with local relief of stress in a number of boreholes penetrating a limited volume in the vicinity of the point at which the stress is to be determined. The stress is assumed to be constant throughout this volume. Leeman1 has described a number of the instruments that have been developed for making deformation or strain measurements in boreholes. Panek2 has described the application of statistical methods to the determination of the average components of ground stress from sets of measurements made in boreholes by means of deformation meters of the type developed by the U.S. Bureau of Mines. In this paper attention is given initially to the strain cell developed for use on the flattened ends of boreholes by the Council for Scientific and Industrial Research (CSIR) , South Africa. The equations required for evaluating the average components of ground stress from measurements made by means of the CSIR strain cell are derived. These equations are similar in form to those applying to measurements made by the borehole deformation meter developed by the U.S. Bureau of Mines. The results of an investigation of the properties of the equations are described. These results are important in the practical use of both the instruments mentioned above and any instrument based on similar principles.

Jan 1, 1968

By Meredith Johnson

THE year 1924 saw little change in the production of oil and gas it either Pennsylvania or New York. In the early months of the year the price of Pennsylvania crude oil, $4.00 to $4.50 a barrel, was sufficiently high to cause operators to lay plans for rather extensive drilling opera-tions. But when, in August, the price dropped to $2.85 a barrel, there was no inducement for new work and drilling was curtailed. In spite of the curtailment, however, the combined production of the two states for the year showed a slight increase over 1923, the production being 8;859,000 bbl. in 1923, and 8,901,000 bbl.1 in 1924. The increased production was due entirely to. the continued development of flooding operations in the Bradford field, all other oilfields showing a decline for the year. TABLE 1. Production of Crude Oil in Pennsylvania and New York for the Last Ten Years a Production, Barrels Production, Barrels Year Year Pennsylvania I New York Pennsylvania I New York 1915 7,838,000 888,000 1920- 7,438,000 906,000 1916 7,593,000 874,000 1921 7,418,000 988,000 1917 7,733,000 880,000 1922 7,425,000 1;000,000 1918 7,408,000 809,000 1923 7,609,000 1,250,000 1919 8,137,000 851,000 1924 7,535,0006 1;366,0006 a U. S. Geological Survey figures. b Estimated. Much of the drilling in the southwestern part of Pennsylvania was done in search of gas. Natural gas in Pennsylvania is fast being recognized at its true worth and the increased prices allowed 'the gas companies for their product induced quite a bit of new work. The relative importance of natural gas compared with manufactured gas is shown in Table 2.2

Jan 3, 1925

By Earl Hunner

IT is common knowledge that the iron orebodies of the Mesabi range lie nearly horizontal and are of trough or blanket-like types. These orebodies are from a few feet to several hundred feet thick and vary from a few acres in extent to the size of the largest one, at Hibbing, Minn., which is over 1 mile wide and 3 miles long. They are covered with sand, boulder and clay overburden and occasionally, shallow depths of ledge material, varying in total depth from about 20 to 200 ft. Large areas are not capped with overlying ledge material; the top of the ore lies directly underneath the surface material. Because of the comparatively great tonnage of ore, open-pit mining has made tremendous strides since the first open-pit ore was shipped from this range by the Merritt brothers, from the Mountain iron mine in October, 1892, and along with the great development of open-pit mining on the Mesabi range has gone a tremendous change in the character of equipment used.

Jan 1, 1930

By Arthur A. Center

WAR demand- motivated developments in the zinc industry during 1942. Stocks of Prime Western were built up and High-Grade remained tight. The Prince The Prime Western stocks are expected to be cut down and the demand for High-Grade more easily filled as the Depue reflux plant of the New Jersery Zinc Co. increases - production. Subistition of steel for brass in artillery shell cases will have a considerable effect on the zinc situation of the country one estimate of the saving in zinc in 1943 by this substitution being a little under 100,000 ton, of metal. The metal saved will, of course be High-Grade. If the substitution occurs, the present tight situation in High-Grade may be entirely relieved as new production comes on the market and zinc may find itself approaching a situation as comfortable as that of lead provided the supply of zinc-hearing raw materials is sufficient to keep all reduction plants tip to capacity production. The premium price of the per pound of zinc over set quotas which went into effect early in 1942, helped to bring about the new lead-slag-fuming plant and other new sources of raw materials.

Jan 1, 1943

By Sheldon P. Wimpfen, Ralph H. Sweefser

FOR centuries the pumping of water has been one of the chief problems to be overcome by the persistent men who win the mineral wealth of the world. Profitable operations have often been forced to suspend activities as the mine penetrated well below the water table or when sudden rushes of water were encountered. To operate below the local water level requires continuous pumping equal in volume to the amount of water flow¬ing into the mine workings. Often the water to be removed exceeds the tonnage of valuable material produced. To be above local water level is a valuable asset. Modern mining practice permits nothing short of the extraction of the last pound of profitable ore from a mineral deposit. In the days before the development of mechanical and electrical power as we know it today. water in any quantity was a major

Jan 1, 1948

By R. T. Rometti, C. A. Bossard

INTRODUCTION Whenever a new mining property is developed or a new concentrator is built, considerable time, money, and planning are invested for the exploration, engineering, and construction of the required facilities. Yet, when these facilities are ready for startup, all too often insufficient time, money, and planning are invested in this critical phase of the project. Failure to plan for this phase results in untimely personnel mobilization, insufficient operator training, and inadequately prepared budget estimates, which combine to create excessive costs, lack of communication, unclear responsibility divisions, unnecessary delays, and poor production levels. Insufficient or excessive leadership, due to unclear assignment of responsibility, results in irrevocable problems within the startup team. A carefully planned and budgeted startup phase can avoid many of these problems. SCHEDULING A key element in properly planning the startup phase lies within the area of scheduling. Once the schedule has been established, planning can be greatly simplified through the expansion of each specified item. The overall project schedule should specify the date when the startup and initial operating management team will be brought onto the project. This team should be mobilized at least two years prior to the anticipated startup date, to allow sufficient time to begin to plan, assemble the startup groups for the various areas of the plant, initiate a workable communications system, and implement the development of the training program. This team is responsible for the preparation of a startup schedule, which would detail the dates for all key items associated with this phase of the project. These key items would include training program development, personnel hiring dates, prestartup plant checkout, etc.

Jan 1, 1982

By Prakash C. Kapur

Many balling and gradation system6 generate self- similar size distributions of the agglomerates. Inspection of the experimental data shows that this is also true of the steady state distributions resulting from the granulation of coarse, partially wet powders, for example, the fertilizer feeds. This result is exploited in the derivations of a number of simple and useful relationships that are pertinent to the analysis of these agglomeration systems. The bonding liquid demand of the granulating charge is a third order polynomial function of the dimensionless ratio of feed particle size to median granule diameter in the weight-fraction distribution. The median size, in turn, is the scale factor or characteristic size parameter in the similarity distribution. The granule size distribution, therefore, is completely specified by the liquid content and the similarity function, and so are the process efficiency and the ungranulated component In the product at steady state.

Jan 1, 1977

By Paul Torrey

IN his recent article, Stanley C. Herold described some of the principles involved in oil-field rejuvenation. The purpose of this paper is to present certain facts, based upon observations of systematic water flooding of oil sands in the Bradford and Allegany fields of northwestern Pennsylvania and southwestern New York, which, it is believed, will partially substantiate Mr. Herold's opinions. The writer gratefully acknowledges his obligation to the Forest Oil Corpn., the Kendall Refining Co., the Petroleum Reclamation Co., W. J. Healey, of Bradford, Pa., and the Producers Oil Corpn., of Olean, N. Y., for information included in this article; and he is especially indebted to Jerry B. Newby, of the Petroleum Reclamation Co., for helpful suggestions and criticism in the preparation of the paper. It is obvious that, in the calculation of mathematical formulas for the prediction of oil recovery, uniform conditions must be assumed; otherwise, the applicability of the results of such work will be, by necessity, restricted to the area or individual property for which they were designed. Geologic and physical conditions are so variable throughout the fields where water flooding is practiced that it is difficult to devise methods that can be universally applicable. However, it is believed that there are certain fundamental principles which, when applied with specific modifications designed to meet the conditions existing in local areas or individual properties, may yield considerably greater recoveries of oil.

Jan 1, 1927

By W. Henry Weimer

A successful surface coal operation requires the combined efforts of engineering and operating personnel. In the planning for a mine, machines should be selected to do the best work in getting the coal uncovered, loaded, and transported to the preparation plant. The best system and extent of cleaning will be determined by the market. After the fundamentals of operation have been established, the operating personnel should see they are carried out. There is no simple solution to some of the every day problems facing the operating officials. Here the production engineer with the technical approach, time studies, control methods, past experience, and available records can help in detecting causes of inefficient phases of the operations. With these studies, a careful analysis can be made in setting up the expected standards to be followed. Management can then compare the job under study with the standards and make corrections to solve the problems. 5.2-1. Annual or Daily Coal Production. Once the production cycle has been established, it is paramount that coal sales keep the productivity of the mine as high as possible. A successful company does this by what they call "the control approach." The daily tonnage report is one of the things that is a potent control tool in attaining the goals to be achieved. If production is falling short of the goal, the daily tonnage report will reveal what has to be done in the remaining days of the month or year to achieve the expected schedule. When goals are reached or exceeded, then budgeted tonnages and costs will be reached or exceeded and thus assure attainment of a profit. Failing to keep to the scheduled pace shows up quickly and prominently, facilitating any necessary action to get things back to the projected plans. The sales target is usually set a little higher than the operating production. The sales tonnage is scheduled and sales are made accordingly, slightly

Jan 1, 1968