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The greatest single obstacle in the path of constructive action in making conservation a reality is the inherent discord in the hearts of men. A perfect society doubtless is many millenniums removed from the present generation, but it must be admitted that progress toward a conservative use of our natural heritage with the altruistic concept of the greatest good for the greatest number for the greatest time can be attained only by a society in which discord is reduced to a minimum compatible with the limitations of human nature. Daily industrial discord is witnessed between management and labor which passes the bounds of arbitration and results in stoppages of production, waste of productive capacity, idle capital, idle labor, and the complete loss of the most unrecoverable element of all-time. The conservation of material things cannot progress independently of the conservation of the efforts of the human worker, and the results of these efforts are proportional to life itself as measured in hours and years. Unfortunately discord passes international boundaries, and the story of war is as old as the story of mankind. Our recent attempts of international control of nations appear to be dismal failures. The prestige and power of the League of Nations and the present United Nations declined rapidly after they were unsuccessful in stopping the first outbreak of hostilities after their or-

Jan 1, 1950

By Eric Jette

THE literature on the binary alloys of iron and silicon has been reviewed by Stoughton and Greiner.1 Another even more extensive and detailed survey of the present knowledge has been prepared under the auspices of the Alloys of Iron Research Committee by Greiner, Marsh and Stoughton. Since the latter survey has already been issued in its preliminary form, it will be unnecessary to review the literature in the present article. However, in this connection there should be noted the important work on the crystal structures of the iron-silicon alloys by Phragmén,2 who investigated the entire system, identified the various phases and determined the homogeneity ranges of these phases. It was evident in the surveys cited above that in the range from 0 to 15 per cent silicon, which includes the commercially most' important alloys, the results obtained by thermal analysis, microscopic examination and the determination of electrical, magnetic and mechanical properties were extremely confusing. From time to time various compounds between iron and silicon have been postulated to account for the results yielded by the classical methods, and much argument has ensued. It was presumed that if compounds occurred which are sufficiently diverse in their properties to account for the characteristics of the alloys, they should be recognizable as separate phases but satisfactory proof of this sort has not been found by thermal or microscopic methods. Contrib-uting to the confusion is the fact that the electrical, the magnetic and some of the mechanical properties are "structure sensitive"; i. e., they are influenced to a marked degree by the presence of minute amounts of impurities, the specific characters of these impurities, the grain size, the character of the grain boundaries, small general or local strains, etc. Thus interpretations of the discontinuities in the various property versus composition curves that identified these discontinuities with phase changes or compound formation have always been open to question.

Jan 1, 1933

By Morgan Walker

INTERMITTENT injection of gas in gas-lift pumping is a variation of the common practice in that the gas is' .delivered to the well for a short, period, called the "on time," followed by a period during which none is admitted, called the "off time," instead of being admitted continuously at a constant rate or by intermittent flowing in which it is occasionally delivered to the well in just sufficient quantity to flow off the accumulated head of fluid. The term "gas" is used throughout this discussion but it should be remembered that in so far as the operation is concerned either air or natural gas may be used. The equipment at the well is the same as commonly used in gas-lift installations and gas may be admitted to either the tubing or the casing. It seldom occurs that all the wells on a lease can be pumped economically by intermittent injection from one header. Wells that. have flow characteristics which permit their being handled together have their intake lines grouped at a central compressor station. Well groups may consist of two or more wells. The total volume of gas delivered by each group of compressors goes to one well at a time through a quick opening valve, each well connected to the header receiving its charge of gas in turn. Special cases may require a deviation from this arrangement. The distribution of the gas to the different wells is effected by an automatic timing device which operates quick-opening valves on the intake lines. The timing mechanism may be actuated by electricity, liquid or gas pressure. The essential factor in the operation of the timing mechanism is that as one intake valve is closed another must be opened.

Jan 1, 1928

By ir. H. Eraly

At the Zolder mine a S/7 computer is used for two purposes : - to monitor production at the coal face - to monitor the distribution of mine cars. By using sensors attached to equipment at the coal face and at the loading points, the computer provides realtime information and also summarized reports, which help management to control production better. The computer will display this information to the control room, where two operators monitor all production events and the availability of the right numbers of mine cars at every production face. All benefits obtained from the system are described.

Jan 1, 1977

By Joseph Hartshorne

The nature if this process and the general course of its development have already been described by me in two papers read before the Institute.* Since the latter paper mas read, in February, 1898, the development at Kladno has been almost altogether in the direction of using metal direct from the blast-furnace. This has now been the regular practice for about a year. The molten metal is brought from the furnace in ladles, without the intervention of any mixing- or accumulating-reservoir. The plant remains practically the same as originally described by me,† except that the primary furnace has been enlarged as much as was permitted by the existing conditions. This was done primarily in order to increase the capacity of the

Jan 1, 1901

By S. J. Im

Bupyung Silver Mines daily treats average 14 tons of concentrates containing 9,000 g Ag per ton. Bupyung Silver Refinery uses Merrill Crowe process to recover the silver from the leach solution containing 1.0 g/l Ag; Series of experiments were carried out to recover the silver from the solution by means of direct electrowinning in place of Merrill Crowe process. The recovery of the silver was 99% when the cell voltage and the retention time were 1.9 v and 3.0 hours, respectively. Power consumption was 3.2 Kwh/kg of Ag. It was found that impurity buildup was not significant during the recycling. The direct operating cost for the electrowinning was evaluated to be $ 0.35/kg of Ag.

Jan 1, 1984

FOLLOWING- the major explosion disaster in the Orient No. 2 mine of the Chicago, Wilmington and Franklin Coal Co., West Frankfort, Ill., on December 21, 1951, resulting in the death of 119 miners, an investigation was made by the U. S. Bureau of Mines under the direction of J. J. Forbes, Bureau director. The subsequent report concluded that the disaster. was caused by the emergence of a-large body of explosive gas from an abandoned area and simultaneous short circuiting of the ventilating current; the gas was ignited by an electric arc from nonpermissible electrical equipment and the flame was propagated throughout a large part of the affected area by coal dust and possibly by gas from other worked-out and abandoned areas. An immediate repercussion of the disaster was the opening of hearings by the. Senate Labor and Public Welfare Subcommittee on the Neely Mine Inspection Bill (S. 1310, introduced April 11, 1951) which would give federal coal-mine inspectors power to enforce safety recommendations by ordering the withdrawal of all employees where conditions constitute an imminent danger to their safety. Two days of testimony, January 24 and 25, disclosed that coal operators were not in agreement on the bill, although John L. Lewis, speaking for the UMWA, and J. J. Forbes, for the Bureau of Mines, were advocates.

Jan 1, 1952

By H. C. Fiedler

THE development of the cube-on-edge secondary re-crystallization texture in Si-Fe strip depends upon the ability of inclusions to restrain normal grain growth. This ability is determined by the number and size of inclusions, which, for a given composition, is controlled by the thermal history of the material during the prior processing.' It has been shown2 that increasing the silicon content decreases the solubility of sulfur, and it is the purpose of this note to show the consequences of this decreased solubility for secondary recrystallization. Heats were made as previously described and cast into graphite molds.' The compositions are shown in Table I. Slabs 1 in. thick were cut from the ingots and either hot-rolled from 1000°C in the as-cast condition or after one of the heat treatments described later. The processing to the final gage of 12 mils followed the previous procedure.' To avoid cracking, the 5.2 pct Si alloy was cold-rolled at 150" to 200°C rather than at room temperature. The percent cube-on-edge texture developed by isothermal heat treatments was determined by dividing the maximum torque measured on disk sam-

Jan 1, 1968

By W. A. Backofen, M. L. Ebner, D. H. Avery

Slip on (11221 planes, which do not contain a close-packed direction, has been identified on crystals strained at —190°C. Evidence is also presented to show that (1071) pyramidal slip is a mode of deformation at 25ºC in a limited orientation range. PYRAMIDAL slip (l011) <1120> in magnesium at elevated temperatures has been established for some time.1-2 More recently, Burke and Hibbard reported this mode of deformation at 25"C, but their results were questioned by Craig.&apos; Also, as far as the present authors know, slip in magnesium on pyramidal planes of the second order, Type II (1122)) has not previously been reported, although Gilman"," identified (1122) slip in another hexagonal metal

Jan 1, 1959

Manganese deposits discovered in Maine may solve one of the problems facing the steel industry today. Diamond drilling is scheduled to start in Aroostook County to determine whether the ore is of acceptable grade. The Bureau of Mines estimates the deposit contains several hundred million tons. If true, it means about a 30-year supply. The steel industry presently imports about 90 pct of its needs. Noranda Mines, Ltd., is planning a sulphur-iron plent for Ontario&apos;s Niagara Peninsula. Although contracts have not been signed, a substantial agreement has been reached with American Cyanamid, Ltd., whereby the Noranda plant would be constructed adjacent to Cyanamid&apos;s chemical plant at an estimated cost of million. The unit would treat approximately 100,000 tons of pyrite concentrate annually. San Manuel Copper Corp., wholly-owned subsidiary of Magma Copper Co., is asking the RFC for a $111.28 million loan for development of a copper orebody in Pinal County, Ariz. The property s said to be capable of producing 10 million tons of ore annually. San Manuel plans to construct facilities for processing 30,000 tons of ore and for smelting 800 tons of concentrate daily. An Aeromagnetic map covering 120 sq miles of the Wichita Mountain area in southwestern Oklahoma indicates a possibility of iron production from titaniferous magnetite deposits of the Raggedy Mountains, northwest of Lawton. The map shows an area in the north central part of the region which may prove favorable to further development.

Jan 1, 1952

By T. S. Govindan

The first step in energy conservation in any industrial plant involves implementing many of the day-to-day "housekeeping" items, such as fixing leaks, turning out lights, etc. When this step has been accomplished, additional opportunities require a detailed analysis of the energy systems, evaluation of risks and costs, and assignment of priorities. Examples of conservation schemes drawn from the experience of Du Pont&apos;s Energy Management Consulting Services will be discussed. The utility of heat balances for kilns and dryers in minerals processing will be outlined. The input needed from management for the success of conservation efforts will be discussed.

Jan 1, 1981

By Gary E. McIntosh

This paper will discuss a US Bureau of Mines project designed to assess and predict the impacts which surface coal mining will have on the regional shallow groundwater systems in the Powder River Basin. The primary objective will be met through the accomplishment of the following: (1) The design and establishment of a regional network for monitoring shallow groundwater systems in the basin; (2) monitoring the direction and rate of flow, water quality, and aquifer characteristics of the shallow groundwater systems; and (3) development of a regional groundwater simulation model, with appurtenant subroutines to determine local effects.

Jan 1, 1980

By H. F. Porter

MUCH has been written relative to the errors involved in the use of a galvanometer for measuring thermocouple electromotive forces. In general, it may be said that accuracy with a galvanometer is secured only at the sacrifice of durability, unless manual adjustment is made in the operation of the instrument to overcome the errors of resistance. and resistance changes. The pyrovolter and the potentiometer both require manual adjustment for every reading, readings being taken on a "null" method. To the end that some of these balances may be eliminated and only an occasional balance be made as a check reading, the "continuously deflecting pyrovolter" was developed. Essentially, the operation of the continuously deflecting pyrovolter is to determine the resistance of the thermocouple circuit, though its value is not noted or indicated, then throwing in series with the thermocouple sufficient resistance to bring the sum up to some standard value for which the indications of the galvanometer will be correct. This result may, however, be accomplished in a somewhat simpler manner, for which general method patents are now in the course of application. If we devise a galvanometer circuit so that by means of a simple adjustment the resistance of the entire circuit will be rendered equal to some constant predetermined value, we may rely on the galvanometer to give correct e.m.f. indications (assuming that the errors of temperature resistance coefficient and cold junction have been properly allowed for), and will indicate temperature continuously where the e.m.f. measured is developed by a thermocouple.

Jan 9, 1919

By Frank Firmstone

THE indicator cards shown herewith were taken by the writer in June, 1877, from the water-pressure blowing engine of the Longdale Iron Co., at Lucy Selina Furnace, Longdale, Virginia. A description of this engine with figures, and some indicator cards, was published by Washington Jones, Esq., Superintendent of the I. P. Morris Co.,* in the Journal of the Franklin Institute for May, 1877, to which those desiring a full account are referred, but for convenience the principal dimensions, etc., are given below. The machine consists of a pair of horizontal directacting blowing engines, connected at right angles to a common fly-wheel shaft. The blowing cylinders are 4 ft. diameter by 5 ft. stroke; the water cylinders were 18 in. diameter by 5 ft. stroke as built. Both water and blowing cylinders are double acting. The water valves are balanced piston valves, 18 in. diameter, moved directly by eccentrics on the fly-wheel- shaft. Great care was taken to have the areas of the ports and passages at least equal to the area of the working piston. The engine is set about 14 ft. above the tail-race, and the * The engine was built by the I. P. Morris Go., from drawings made by Messrs. Tuws and Hartman.

Jan 1, 1879

By Victor Rudenno

Feasibility studies for mining projects traditionally involve in their final stages a lengthy process of repetitive trial and error discounting, in calculating the discounted cash flow rate of return resulting from the respective yearly after-tax cash flows. Also, probability analysis and sensitivity analysis (in particular) require extensive additional calculations with each change of any project parameter . These inefficient repetitive procedures have two unacceptable results: 1. they are not flexible enough to allow ready analysis of dependent parameters , and 2. they require resort to high-capacity centralised computing facilities with their inherent impersonality, rather than a convenient and available desk calculator - a factor of particular importance to top mining management. Such problems can be overcome if the mining project can be represented by a reasonable straightforward mathematical economic model. The most flexible and appropriate model has been found to be one in which a maximum and minimum value for each of n parameters are supplied to a program which determines a large number of systematic combinations of parameter events and then statistically analyses them to determine the resulting coefficients of the model. In this paper the authors discuss the selection of the most appropriate type of model and outline the steps followed in its development and application.

Jan 1, 1977

By Philip W. Guild

Approaching exhaustion of areas where traditional prospecting methods can pay off and sharply rising costs require increasing sophistication in planning exploration. Most outcrops, not only of ore and gossan but also of obvious zones of alteration, have been examined; many of the anomalies readily detectable by geophysical means have been drilled; geochemical surveys now cover extensive tracts. How should the explorationist proceed to find the ores that will keep his company in business and supply the world with the energy and raw materials it needs? Two courses are open to him: (1) saturation coverage by geology, geophysics, geochemistry, and drilling in the expectation that something will turn up or (2) critical analysis of the factors responsible for the concentration of valuable minerals in the earth&apos;s crust. The successful explorationist applies both methods to the limit of his resources. The second course, analysis of geologic factors, also comprises two principal lines of research: (1) ever more detailed study of the chemistry (including isotopic analysis) of the ore and gangue minerals of known deposits in an effort to understand how they were formed and (2) increasingly detailed mapping of their environment to determine the reasons for their localization. Again, both are very necessary.

Jan 1, 1971

By P. Sen

Frequently during the processing of minerals very fine particles are generated which are difficult to recover by conventional separation techniques and are rejected with waste water from mills. A method has been evolved for the continuous recovery of such fines by allowing the suspensions to flow through a rotating cylinder. Theoretical analysis of the trajectory of particles have shown that the efficiency of separation increases with R.P.M., tube diameter, particle diameter and density. Experiments carried out with the overflow from a hydrocyclone containing particles in the size range of 2-10 microns gave a separation efficiency of 60-70% with an R.P.M. of 3500 of the rotating tube.

Jan 1, 1980

By S. L. Crouch

The application of a simple, two-dimensional computer technique for evaluating rock burst potential in cut-and-fill stopes was investigated. The principal purpose of the study was to compare the effectiveness of high-modulus fill and destressing as aids in the control of rock bursts. Two conclusions that are probably of general applicability are drawn. First, high-modulus fill is ineffective as a means of increasing the mine stiffness and acts to control rock bursts only if it supports enough load to reduce substantially the stresses on the unmined vein material. Second, destressing is most effective if it is performed when the vein material is near the point of failure.

Jan 1, 1975

By J. B. Evans

Maintaining overall optimum profitability at a mine site necessitates constant reassessment of operating strategies. In essence, each strategy is a particular combination of envisaged capital expenditure, income flow and elapsed time. Selecting a strategy, based on profita¬bility potential requires each contemplated strategy being subjected to discounted cash flow analysis; even with a computer such analysis can be cumbersome. The chapter discusses a &apos;shortcut&apos; technique which assigns profitability rankings to alternate strategies and iden¬tifies those aspects of a. strategy which impact heavily on profitabil¬ity. This technique can yield quick assessments of sufficient accuracy for many operating strategy decisions. taken on site at on-going mines.

Jan 1, 1978

By Waldemar Gooskov

IN his well-known work,1 published in 1867, P. Ritter von Rittinger gives the following formula for the velocity of a particle settling in still water: v=C/D(a -1) and for average grains he assigns to the constant C a value of 2.44. As is well known, the value of C depends on the shape of the grains resulting from crushing, and it is obvious that values obtained for coal particles will not only be very different from those for ore particles but will even be characteristic of coal from a certain seam. The only way of finding an accurate value of C, applicable to conditions in Russia, where all coal-washing plants are built on German principles, is to conduct a series of tests of which the results will determine what value of C is to be used. In the investigation outlined in this paper the theories of Prof. Robert H. Richards2 were taken as the basis of the tests; the slimes were removed from the charges to eliminate the trouble of handling them; and to obtain accurate results free from errors inevitably resulting from human observation, photographic apparatus was used and a series of pictures taken which form the basis for constructing a suitable diagram of velocity vs. time.3

Jan 1, 1928