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By Freeman Bishop

More than a few discussions are taking place these days among management economists seeking a way out of the dilemma of lower productivity vs. higher labor costs. Most suggestions would be illegal under present antitrust laws. Otherwise interindustry cooperation could be used to divide up some of management's tasks. Or price structures might be tuned to the special machinery and skills of some plants. Both remedies would be under attack almost immediately. There is one other remedy that is getting lots of attention: some form of compromise between management and labor to phase out no longer needed work practices that unions insist shall be retained. Railroads are the national industry suffering the most from this disease, still known as "featherbedding," an epithet coined by the railroaders themselves.

Jan 1, 1971

John Langton, New York, N. Y. (communication to the Secretary*):—In Mr. Firmstone's discussion (Trans., xli., 912) the formula he gives for the periodical payment—his equation (2)—may be simplified in form. The expression given by Mr. Firmstone is : q=S(l+ r) 1-(1+r)-(1+r) r which is a simpler form to use in calculations. Where S= principal to bc extinguished. Q = periodical payment or charge for sinking-fund, r = rate of interest per period (i. e., interest on $1 per period). n = number of payments or periods. Kent's Mechanical Enyineer's Pocket Book, under the heading Annuities, equation No. 5, gives : " The annuity which $1 will purchase for any number of ytlars n is * Received Jiily 16, 1911.

Jan 1, 1912

By A. F. Crawley

THIS communication reports measurements of the densities of dilute liquid alloys of 0.1 and 0.5 pct Ag in Sn over temperature ranges of 170" and 210°C, respectively, above the melting point of pure tin (232°C). The work was earried out to provide accurate density data for some liquid diffusion studies performed by Davis.1 Densities were measured using a pycnometric technique established in this laboratory. Earlier papers2, 4 attest to the accuracy of ±0.05 pct and the reliability of the method. Tin, 99.999 pct pure, and silver 99.99 pct pure, were melted in a graphite crucible in a vacuum furnace and held at temperature for 10 hr to ensure homogenization. Ingots suitable for machining

Jan 1, 1970

By Paul L. Allsman

Butte mining district contains extensive manganese vein deposits forming a peripheral zone. Oxidation in the veins studied usually extends to a depth of about 75 ft. Secondary minerals formed by oxidation were found to be ramsdellite-always accompanied by intermixed pyrolusite-and cryptomelane. Enrichment of the gossan is accomplished by reduction of weight upon oxidation; theoretical enrichment is 32.2 pct. Additional enrichment is caused by leaching of soluble minerals, particularly calcium and magnesium carbonates. Butte mining district contains extensive manganese vein deposits in the outer zone, surrounding the copper and zinc deposits and corresponding to the well known silver zone. This article describes the mineralogy of the manganese veins, the oxidation and enrichment processes, and the use of this information in prospecting.

Nov 1, 1956

By G. E. Karantzavelos

Anew flotation process to recover alunite from low-grade alunite ores is described. The process begins with run-of-mine ore, reduced to less than 5 mm (0.2 in.), being preconditioned with the reagents before grinding and alunite flotation. From the preconditioning step, ore particles, impregnated with reagents, form pellets that subsequently disintegrate into the pulp during grinding. The second step is basically a standard alunite flotation step. Pilot plant test results show that an alunite concentrate assaying at least 85% alunite and less than 5% silica can be produced. Laboratory and pilot plant results were in excellent agreement, indicating that the new process is a viable means of alunite beneficiation. Plant results, using the new process, were superior to results from conventional alunite flotation procedure.

Jan 1, 1986

Two 6.17-m-diam (20.25-ft) shafts, said to be the largest ever opened with mechanical raise boring techniques, were completed in May and June 1978, at Monterey Coal Co.'s No. 1 mine near Carlinville, Ill. According to the shaft contractor for the project, Frontier-Kemper Constructors, the openings are 60% greater in cross section than the largest previous raise-bored shaft, which had a diameter of 4.85 m (16 ft). Both vertical shafts are 93 m (305 ft) in total depth, with the upper 28-30 m (90-100 ft) sunk and lined by conventional methods through unconsolidated overburden and the remainder mechanically bored through sedimentary rock. The two shafts will be used for service access as well as to augment ventilation.

Jan 12, 1978

By J. B. Hiskey, W. J. Schlitt, W. G. Pitt

Aqueous SO2 (sulfurous acid) is an interesting chemical compound. It functions as a reagent in various hydrometallurgical systems, but also represents an undesirable constituent in gyro- and hydrometallurgical effluent solutions. When present in such streams, SO2 can be oxidized to the more stable sulfate form to avoid exsolution of SO2 as a source of fugitive emissions and to simplify standard water treatment plant operation. This study provides information on the stoichiometry, kinetics, and mechanism of SO2 oxidation using oxygen and an iron salt catalyst with solutions containing 0.05-20 g/L (0.002-0.7 oz per gal) SO2. The effects of iron salt concentration, oxygen pressure, temperature, degree of agitation, and pH on SO2 oxidation are also described.

Jan 1, 1984

By R. W. Smith, K. H. Lee Discussion by Fred C. Bond

Fred C. Bond (Tucson, Ariz.) — This is a valuable paper presenting much well directed research testing. It describes a practical method by which the long and relatively accurate Bond closed-circuit grindability can be adapted to a known ore so that results of comparable accuracy can be obtained on the same ore from much shorter batch grinding tests. This can be very useful in control work. In large mills a routine batch grinding test on the head sample can be made each day, or even each shift, to check grinding performance by comparison of the work index from each mill grinding section with that obtained from testing. However, it would be well to re-standardize the batch test against a Bond test, perhaps once a week at

Jan 1, 1969

By George C. Toland, Ronald E. Versaw

Most existing impoundment ponds and dams leak effluent into the soil or rock upon which they are constructed. However, proposed environmental legislation will require very stringent control of the release of toxic effluents such as cyanide. More exacting investigation, design, and construction techniques than have been used in the past will be required to satisfy these new regulations. The types of field and laboratory investigations required to develop the data for the design of an impoundment system containing toxic effluent are discussed, together with the technical considerations necessary to design this system. Design topics include reservoir sealing with natural and man-made materials; embankment sealing; embankment design considering stability, surface hydrology, capacity, and downstream catchment basins; and special implications of cyanide effluents.

Jan 1, 1977

By Alden B. Greninger

THE study of mosaic structure of crystals1 has been confined until recently to the field of theoretical physics Crystallographers, in general, have neglected the subject, although X-ray crystallographers constantly make use of formulas for intensities of X-ray reflection as modified by mosaic structure Work on mosaic structure has centered chiefly on the task of proving or disproving the secondary-structure theory of Zwicky,2 and very little attention has been paid to the visible imperfections of crystals A Goetz has been responsible for most of the supposed experimental confirmations of Zwicky's theory 3 On the other hand, Smekal,4 and Orowan,5 among others, maintain that these is neither theoretical nor experimental evidence to substantiate Zwicky's secondary structure

Jan 1, 1935

By Francis S. Kendorski

Caving offers the lowest cost per ton of ally large-scale mining method, but its successful application demands an ore body that conforms to several rigid requirements. The deposit must be of wide areal extent, massive and not spotty in ore values, and insensitive to ore dilution. It must also be a rock mass that breaks up readily. There are only three active caving operations in the US-Climax, Henderson, and San Manuel-but caving methods have recently-taken on new importance as deeper, lower grade mineral occurrences and ore bodies are found. These deposits are too deep for surface mining methods, and too low grade to support any type of underground mining except a bulk method such as caving.

Jan 6, 1978

By J. W. Eckerd

Anthracite mining developments have not been as spectacular as the advances made for bituminous coal. The reasons are well known, i.e., steeply pitching seams of the western, eastern, middle and southern fields, and the physical conditions of the strata in which the seams are situated. Beds with moderate pitches (30º to 35º or less) have been mined with coal planers, longwall with movable props, shaker chutes, coal borers and large diameter boring machines. However, the use of this equipment has been limited to a relatively small portion of the production. Long-hole drilling has been developed from a point where holes of 25 or 30 ft have been replaced by those up to 130 ft. This has been possible through the introduction of primacord and similar detonating agents that can fire a long train of explosives with one cap. The usual practice in long-hole mining is to drive a gangway, chutes and monkey heading, or return airway, in the normal development manner. Two breasts can then be driven from the lower to the upper level to act as openings for the beginning of the long-hole work. Following completion of the development, holes can then be drilled from the monkey headings 100 ft or more up the pitch through the coal to within 15 ft or more of the upper level, depending on the nature of the coal on the roof. The thickness of the coal bed determines the spacing of the long holes, although they usually are on 6-ft centers for a 6-ft thick coal seam. The Bureau of Mines has conducted extensive investigations and tests on the development of a hydraulic mining system to be used in conjunction with hydraulic hoisting. Tests were conducted in cooperation with a large anthracite producer in a coal seam from 10 ft 6 in. to 15 ft in thickness and on a pitch from 0º to 20. This particular mining procedure is adaptable only to thick seams on relatively flat pitch as the maneuverability of the hydraulic jumbo is an important restricting factor.

Jan 2, 1968

By Ferdinand S. Ruttmann

There is now in use at the mines of the Chateaugay Ore and Iron Co., at Lyon Mountain, New York, an ore-concentrating machine or jig, which, in view of the increasing attention given to the subject of concentrating lean ores of iron, seems worthy of notice. This Conkling Jig, as it is called, is not entirely unknown, having been used at several places with more or less success; but as yet, I believe, no drawings of it or records of its work have found a place in print. Although the jig will be found to be merely an adaptation of old forms, there are several points which deserve attention, particularly the method of central discharge, of freeing the bearings from grit, and the rotation of the sieve or screen. The ore-body at Lyon Mountain consists of a bed of rather compact, granular magnetite, occurring in a gueiss formation. The side walls of the ore-body are not sharply defined, the ore 011 either side becoming gradually poorer as the distance from the central point of the body increases. It is this lean ore, which, before the introduction of the jigs, was thrown away as waste, that is now concentrated. The material treated conseqnently consists of magnetite, intermixed with the component parts of gneiss, viz. quartz, felspar, hornblende, and mica. Grains of trap also form part of this material. These come from dykes of trap, which cross the ore-body at intervals. The ore which is to be concentrated usually contains from 30 to 40 per cent. of metallic iron. It is first crushed to the size of two inches, or less, by two large Blake crushers. The material from these crushers passes by a shute lined with screens, having holes 2 inches in diameter, to a second set of four crushers, set so as to close to one inch. The product from this set of crushers, together with that which passes through the screens in the shute, is then taken by an elevator to the top of the mill, and passed through a revolving screen, perforated with ) inch holes. The ore which passes through the screen goes to the jig-hoppers ; that which passes over goes to a third

Jan 1, 1888

By H. E. Ellis, O. L. Patterson, Granville Dutton

A large-scale water-injection program for the Holt Bryant reservoir of the Delhi field has been established by means of the new automatic multi-pool analyzer. The objectives of this program were to increase reservoir pressure and eliminate a cross-dip gradient of 200 psi. Pressure increases during the first 15 months of operation have allowed for increased oil production rates of 2,600 BID or 25 per cent. To determine the required water injection it was necessary to predict natural water influx ram. Elimination of the pressure gradients required the water-injection program to account for the fluid migration and pressure interaction between segments of the reservoir. An integral part of the ana1ysis included the determination of in-place volumes of oil and gas. The operation of the automatic multi-pool analyzer in determining the water-injection program is described. New features of the analyzer inc1ude an automatic maferial balance analog and a leart-squares computer for determination of unknown reservoir properties. Operational procedures are sufficiently simple to allow direct use by reservoir engineers on a routine basis. The rapidity and accuracy with which problems may be solved permit repeated ana1yses as a check upon reservoir performance. INTRODUCTION This paper describes the use of a new analog com- puter in determining the optimum injection program for a complex reservoir. The Holt-Bryant (Fig. 1) is the major reservoir in the Delhi field of Louisiana. Production is from the Tuscaloosa at subsea depths of 2,970 to 3,286 ft. The sand dips to the south and southwest from three to five degrees. The reservoir is approximately 12 miles long and varies in width from 1/2 to 2 miles. Various calculations have placed the initial volume of oil in-place in the wide range of 275 to 355 million STB. Two small gas caps were initially present in the reservoir. The Holt-Bryant reservoir was discovered in Dec.. 1944, and was fully developed with 188 producing wells by 1948. After development was completed, an east-west pressure gradient began to establish itself. This

Jan 1, 1957

By L. A. Morley, W. T. Parry

Engineering design problems encountered by mining engineers often depend on the properties of natural granular materials such as soil, poorly consolidated sediment, fault gouge, and hydrothermally produced clay. The physical properties of such granular materials frequently are determined by the properties of silicate clays. In most mining applications, the clays are in contact with water. Swelling of clay due to water infiltration can interfere with underground support and haulage systems. Water-saturated clay on fault, fracture, and bedding planes causes slope failures in open pit mines, roof falls and heaving of weak underclays in coal mines. Water may be removed and cementing agents may be produced in clays by electrical methods. When an electrical potential gradient is applied to a charged capillary by two electrodes, water moves toward the negative electrode.1 This electrokinetic phenomena is known as electroosmosis and has been used to successfully dewater clay minerals which lack strength because of water. A consolidation effect occurs when the flow of water is accompanied by a decrease in water content. Electrochemical changes in the clay result in cementing and irreversible hardening. Theory A mathematical basis of electroosmotic phenomena is presented by Helmholtz.3 Smoluchowski5 modifies Helmholtz’ model and presents Eq. 1 to describe fluid flow velocity due to electroosmosis. For this formula, the zeta potential can be measured experimentally. The Helmholtz-Smoluchowski model is reasonably valid for clay aggregates with large pores saturated with fresh water or dilute electrolyte solutions.° An assumption used for Eq. 1 (equations are given Table 1; terms are defined in Table 2) is that the thickness of the electrical double layer surrounding the clay particles is small compared with the pore radii. Because this is generally not the case, Schmid7 presents Eq. 2. The volume charge density in the pore may be approximated from cation exchange capacity and porosity measurements. Casagrande8 offers a semi-empirical relationship (Eq. 3) for volume rate of electroosmotic flow and finds that k, is relatively constant for most clays with an average

Jan 1, 1972

By Edward A. Sayre

In shaft sinking for cod mines, the cost item greatly influences the method adopted. This holds true especially when soft material must be traversed. The average life of a coal mine is short. This is due either to the limited area of the coal basin or to the great expense of maintenance and haulage underground when the entries are extended a considerable distance from the hoisting shaft. Therefore, the engineer in opening a coal mine is confronted with the fact that the cost must be kept within certain bounds else the venture will prove unprofitable. For this reason he may be prohibited from adopting certain safe, but expensive, methods that are used in sinking caissons for foundations, driving transportation tunnels, or other work of permanent construction. A common method of sinking through difficult ground employs the aid of a steel shoe pushed ahead of the shaft timbers. Another is the drop-shaft method. These two methods were used in sinking the main shaft and the air shaft of the Eagle No. 3 mine, at Des Moines, Ia., and the following data show the relative success and cost of the two methods of sinking under the same conditions. A drill log of the material to be penetrated was as follows (see Plate 1, Fig. 1): Thickness, Total Depth, Ft. In. Ft. In. Drift................................... 38 38 Sand..................................... 2 40 Drift.................................... 2 6 42 6 Jointed clay.............................. 5 6 48 Drift, firm............................... 10 6 58 6 Clay, with sand streaks.................... 3 61 6 Sand.................................... 12 73 6 Shale, with two thin beds of coal and thin strata of rock......................... 86 6 160 Rock.................................... 5 165 Coal..................................... 3 9 168 9 Main Shaft Sunk by Steel-Shoe Method This record shows the first 73 ft. to bc of drift material, the lower 12 or 15 ft. of which was sand. The remaining 92 ft. to the coal was shale and rock, and offered no trouble in sinking.

Jan 1, 1917

By T. V. Moore

IN many of the important problems of the petroleum engineer, it is necessary to know accurately the laws governing the flow of gas and liquid mixtures in vertical' pipes. Although much work has been done along these lines, no satisfactory solution to the problem has been found. A good theoretical discussion of the energy balance in a gas¬lift has been published-by Versluys.1 One of the most important factors affecting the efficiency of the flow of oil and gas mixtures is slippage, and in most of the experimental work that has been done no provision has been made for the measurement of this quantity. As Versluys pointed out, since there is no method now known to estimate it from the data usually taken; slippage must be determined empirically. This paper presents the results of some work carried on to, measure slippage in short experimental gas-lifts. As shown herein, slippage can be easily calculated in a vertical pipe carrying a mixture of oil and gas if the fractions of the pipe occupied by liquid and gas respectively are known. In this work, the fraction of the pipe occupied by the liquid was measured under a wide variety of conditions and the relationship between this fraction and other quantities, which are easily measured in ordinary work, was determined. It was hoped that the quantitative relationship obtained from this work could be used-for making accurate calculations in flowing or gas-lift wells, but unfortunately it did not check satisfactorily when applied to actual wells. Apparently flow in long flow pipes is mote efficient than in the short ones used for the experimental work. Nevertheless, it is felt that the data themselves are of interest; that the method of attack may be of value in future work and that the relationship derived between slip and the relative velocities is a contribution toward the solution of the gas-lift problem.

Jan 1, 1931

By J. B. Dyess, H. A. Miley

Tarnish films on some of the common metals (particularly on copper and silver) have been of much scientific and commercial concern for a long time, but before the development of the electrical method1 of measuring film thicknesses there was no satisfactory quantitative approach by which to study the separate parts of these complex films. This method has been adapted to the measurement of duplex (cuprous-cupric) oxide films on copper.2 In the present work it has been used to measure tarnish films on copper when they were mixtures of cuprous oxide and cuprous sulphide, and also when they contained cuprous oxide, cupric oxide and cuprous sulphide, each component part being measured at a different potential value. Oxide-coated copper specimens, prepared by heating copper in air at chosen temperatures for given periods, were exposed to moist hydrogen sulphide in air to forml the various oxide-sulphide films studied. The comparative resistances afforded by (I) different thicknesses of oxide films, and also (2) equal thicknesses of oxide and sulphide films, against severe attacks of hydrogen sulphide were measured. The electrical method requires that the time be observed for the cathodic reduction of each part of the film substance, and these respective time values multiplied by the constant current give the corresponding quantities of electricity expended. Then each millicoulomb per square centimeter represents a film thickness of M X 108____ 2DX 96,494 X 103 where M is weight of oxide (or sulphide) giving one gram-atom of oxygen (or sulphur) for cathodic reduction, D is density of the oxide (or sulphide) and t is the thickness in Angstrom units per millicoulomb per square centimeter. The value of t for cuprous sulphide (cubical) is 14.27, and is obtained by substituting 5.78 for D and 159.20 for M in equation a. Previous values hf t for cuprous and cupric oxides (12.36 and 6.39, respectively) were used in the present work.

Jan 1, 1939

By J. B. Dyess, H. A. Miley

Tarnish films on some of the common metals (particularly on copper and silver) have been of much scientific and commercial concern for a long time, but before the development of the electrical method1 of measuring film thicknesses there was no satisfactory quantitative approach by which to study the separate parts of these complex films. This method has been adapted to the measurement of duplex (cuprous-cupric) oxide films on copper.2 In the present work it has been used to measure tarnish films on copper when they were mixtures of cuprous oxide and cuprous sulphide, and also when they contained cuprous oxide, cupric oxide and cuprous sulphide, each component part being measured at a different potential value. Oxide-coated copper specimens, prepared by heating copper in air at chosen temperatures for given periods, were exposed to moist hydrogen sulphide in air to forml the various oxide-sulphide films studied. The comparative resistances afforded by (I) different thicknesses of oxide films, and also (2) equal thicknesses of oxide and sulphide films, against severe attacks of hydrogen sulphide were measured. The electrical method requires that the time be observed for the cathodic reduction of each part of the film substance, and these respective time values multiplied by the constant current give the corresponding quantities of electricity expended. Then each millicoulomb per square centimeter represents a film thickness of M X 108____ 2DX 96,494 X 103 where M is weight of oxide (or sulphide) giving one gram-atom of oxygen (or sulphur) for cathodic reduction, D is density of the oxide (or sulphide) and t is the thickness in Angstrom units per millicoulomb per square centimeter. The value of t for cuprous sulphide (cubical) is 14.27, and is obtained by substituting 5.78 for D and 159.20 for M in equation a. Previous values hf t for cuprous and cupric oxides (12.36 and 6.39, respectively) were used in the present work.

Jan 1, 1939

By Thomas Adair

Moderator-Thomas Adair is now a tunnel consultant with Perini Corp., Spring Lake, N.J. He has had 40 years experience in tunnel and shaft-sinking work in both soft and hard rock, as well as subaqueous rock. He has used moles in various locations and has traveled around the world studying the problems. SOME BRIEF COMMENTS ON "MOLES" by Thomas Adair We of the Perini Corp. have been, over the past 15 years, in the forefront of the battle to develop the mechanized miner. We have contributed much to pioneer, develop, and promote the use of the mining machine. Our money and talent have not been spared in this effort. However, we are sorry to say that as of the present time (1968), at least from the economic stand- point, this effort has not been very rewarding. But, I must say to those who are presently involved in the work of building mining machines, do not be discouraged. There is money in it. We of Perini Corp. know because we put it in there. It has been estimated that during the next 15 years, some $20 billion will be spent on underground excavation; more than 13 thousand miles of sub- surface tunnels will be excavated throughout the nation. An aggressive, properly structured research and development effort would produce, within the next five or ten years, a better excavation technology and improved boring system capable of reducing present costs drastically, with a resultant great saving. The time for this effort is now, but where the enabling money for this effort will come from, I have no idea. Machine builders should be encouraged to design and develop a shield- type boring machine capable of continuous mining through varying types of ground or rock by incorporating the possibility of making minor modifications such as change of bit type, power package, etc. Such a machine could

Jan 1, 1970