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(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members. ) Member, age 33, single, desires position as null superintendent or charge of mine and mill. Twelve years' milling, cyaniding and flotation in the southwest and Mexico. Will go anywhere. No. 458. Member, mining engineer and geologist, graduated, from- mining college, age 27, single, exempt, with practice in metal mining, surveying of any kind, field geology and ore testing, desires to .engage as geologist or mining engineer with a reputable concern in the west or east of. U. S. Hard worker and reliable. No: 459.

Jan 6, 1918

By R. L. Blackwood

The solid inclusion cell for absolute in situ stress measurement has been found to give reliable results in coal. The cell is described briefly, along with the methods of installing, overcoring and taking readings in underground coal mines. The validity of the cell performance is demonstrated by reference to the stress-relief curves obtained during overcoring and a three-dimensional B.I.E.M. analysis of the installation to test for stress anomalies deriving from the geometry of the overcoring groove-borehole-cell arrangement. Case studies of two stress measurement projects using the cell are presented for coal mines in New South Wales, Australia.

Jan 1, 1982

By William D. Schwab

In the technical literature of 1965 and 1966, there were several papers about future power for mining and construction equipment. Most of these papers made the same predictions: •More power •Better reliability and durability •Ease of service and maintenance •Operating economy •The possibility of future environmental concern •The entrance of the gas turbine In the five years that have since passed, some of the 1965-66 predictions have at least partially come true, while others have not been fully realized. Actually the list still appears sound today. Priorities may have changed and details may be different, but the main points cover the requirements for future prime movers quite well.

Jan 1, 1971

By W. N. Marchant, P. T. Brooks, P. B. Altringer, R. O. Dannenberg

The US Department of the Interior, Bureau of Mines conducted laboratory tests to devise a process for recovering a marketable grade of tungsten from the brine of Searles Lake, Calif. The brine contains only 56 ppm W (70 ppm W03). Using ion exchange resins synthesized by USBM chemists, 98% oft he tungsten was extracted from the brine and 92% of the tungsten was recovered as a marketable iron-tungsten concentrate containing 44% tungsten as tungsten trioxide. Although major technical problems have largely been resolved, research is progressing to escalate testing in a process research unit to provide more reliable data for an economic appraisal.

Jan 8, 1979

By E. V. Manlapig, David J. Spottiswood

In recent years great advances in the automatic control of flotation plants have been made, mainly due to the development of reliable sensing instruments to monitor process performance and the development of an adequate understanding of system responses to process disturbances. Some of the control strategies used in flotation plants which apply computer control are presented here. These schemes, which involve the control of collector; depressant, frother, and air and pulp level, are analyzed with respect to their control objectives, control variables, and the instrumentation involved. The knowledge gained in understanding these strategies may be applied in the dew and implementation of control system in other concentrators.

Jan 1, 1981

By W. N. Marchant, P. T. Brooks, P. B. Altringer, R. O. Dannenberg

The US Department of the Interior, Bureau of Mines conducted laboratory tests to devise a process for recovering a marketable grade of tungsten from the brine of Searles Lake, Calif. The brine contains only 56 ppm W (70ppm WO3). Using ion exchange resins synthesized by USBM chemists, 98% of the tungsten was extracted from the brine and 92% of the tungsten was recovered as a marketable iron-tungsten concentrate containing 44% tungsten as tungsten trioxide. Although major technical problems have largely been resolved, research is progressing to escalate testing in a process research unit to provide more reliable data for an economic appraisal

Jan 1, 1980

By C. Coles, J. A. I. Young, W. A. Wyeth, D. A. Fenton, G. W. Herzog

The reliability of large diameter, high horsepower ball mills is paramount when large production and minimum downtime is required. The 518 x 1706 mm (17 x 56 ft) double compartment ball mill at St. Lawrence Cement Co. has the fist gearless drive built in North America and has the world's largest hydrodynamic bearings currently built and running. The machine has seen three years operation and has met its specifications. The mill wm designed by Aerofall Mills Ltd. and the gearless drive built and designed by the Canadian General Electric Co. The paper discusses the operation of the machine from the mechanical, electrical and process aspects.

Jan 1, 1980

By Joseph N. Morrison

A comprehensive solution is offered to the problem of dust emissions at belt conveyor transfer points. Details of enclosure design are discussed and a straightforward procedure for calculating required dust control exhaust volume is presented. Many design variables are taken into account which heretofore have been commonly ignored or inadequately considered. These include belt widths, belt speeds. enclosure openings, material flow rate, material bulk densities, material lump sizes, height of material fall, material temperature, and ambient air temperature. All of these questions are handled by means of a "fill-in-the-blanks" type of calculation form, permitting quick, reliable solutions by relative "non-experts."

Jan 1, 1972

William Kent, New York City: I regret that I have not had the time since the Cincinnati meeting to make as complete a study of Mr. Salom's paper as I wished. I regard it as one of the most important papers that have been presented on this subject, and worthy of complete study. I started out, on the limited time I had, on a system of study which I would recommend to any one else who has leisure to complete the investigation. I took the original report presented at the Cincinnati meeting, and selected from it' such tests as had the analyses reported along with the physical tests, giving the amounts of carbon, phosphorus, manganese, etc., taking only those in which all these elements are given.

Jan 1, 1885

By Robert T. DeGavre

INTRODUCTION The $645 million financing for Inco Ltd's Soroako nickel project in Indonesia not only represents a significant human achievement but also there are certain important lessons that can be derived from Inco's experience in financing the project. The paper will not present a technical assessment of the project since Inco Ltd. submitted a series of papers on this subject at the international Laterite Symposium as part of the 108th Annual Meeting of the AIME in February 1979. BRIEF HISTORY OF THE SOROAKO PROJECT Table 1 summarizes the milestones achieved in the Soroako project and its financing. Exploration Phase A contract of Work was signed on July 27, 1968 by the Republic of Indonesia and F.T. International Nickel Indonesia (P.T. Inco) covering an extensive area of over 25,000 square miles on the two southeastern arms of the island of Sulawesi. The Contract provides that P.T. Inco has the sole responsibility for financing the project and determining the terms on which the financing should be obtained, that P.T. Inco has the right to receive and hold outside of Indonesia foreign exchange revenues and to freely dispose of such revenues, and that Indonesians have the right to purchase up to 20% of the equity of P.T. Inco over a period following start of production. P.T. Inco began field investigations in the Contract Area in August 1968. Preliminary reconnaissance sampling with portable drills broadly outlined areas of favorable laterite terrain which were then systematically sampled on surveyed grids. By early 1971 sufficient exploration work had been completed to indicate that the laterite deposits near Soroako could sustain a major nickel-producing plant (figure 1). Pilot plant studies in 1970 and 1971 at Inco's research station in Port Colborne, Ontario, using two bulk samples of Soroako ore material, also confirmed that the ore could be upgraded and treated for the recovery of its metal values. Feasibility Phase Encouraged by the results of its exploration program and pilot-plant work, Inco Ltd. commissioned Toyo Engineering Company of Japan in August 1971 to prepare a capital cost estimate for a relatively small nickel project called "Stage I". Stage I was to be a single-line pyrometallurqical process plant with an annual capacity of approximately 15,000 metric tons of nickel contained in 75% nickel sulphide matte (see Figure 2). Electric power was to be supplied by a thermal power station. It is important to recognize that Inco's strategy was to develop the Soroako ore deposits in several stages: first, construct a small project to gain experience and to reduce the initial capital outlay and then later expand in one or more steps to a much larger project to achieve maximum economies. The strategy reflected both Inco's financial position in 1971 as its sales and earning dropped sharply and the difficulties previously experienced by Inco in trying to launch in the late 1960's very large "greenfield" nickel projects in New Caledonia and Guatemala. Toyo's Project Development Study was completed. in January 1972. Based upon Toyo's cost estimate for physical facilities, Inco estimated the total capital cost of Stage I to be $115 million. For the next several months, Inco ran numerous in-house financial feasibility studies, using as inputs Toyo's cost estimate and the results of its exploration and pilot plant programs. In September 1972, Inco completed a project feasibility study which was based upon a capital cost estimate of $135 million. The feasibility study was immediately made available to potential partners and lenders. Partner Negotiations The Japanese nickel market had from the outset been central to Inco's planning for the Soroako project. That market had been growing dramatically at rates in excess of 20% per annum during the 1950's and 1960's. Japan had established, for rational security and other reasons, a domestic

Jan 1, 1985

By Kenneth K. Humphreys

INTRODUCTION What is automation? Why automate? Webster's New Collegiate Dictionary defines automation as "the automatically controlled operation of an apparatus, process, or system by mechanical or electronic devices that take the place of human organs of observation, effort, and decision." This definition gives an implied answer to the second question, "Why automate?" Automation, automatic control devices, and process control equipment receive their justification in supplementing or replacing manpower, which results in decreased operating costs. In the past, processes were operated with the minimum amount of instruments needed merely to guide operators. Processes were manually con- trolled by the operator on the basis of simple temperature, pressure, flow, and level indications on a panel. Today the tendency is to design a new plant to operate in a fully automatic manner according to a preset pro- gram utilizing a minimum of manpower. In addition to this direct cost reduction in manual labor, increased equipment capacity results from uniformity of flow and uniform control of process variables. This control eliminates or minimizes surges and permits equipment to be operated at or near its ultimate capacity and, for a given material throughput, permits the use of smaller process equipment. Automatic control, therefore, be it in the field of coal processing or in any industrial field, is simply a problem of economics. Control equipment is justified in terms of its contribution toward increasing productivity, increasing profit margins, or producing a new and salable product at a profit. Instruments and control devices can be divided into two general groups: (1) units which measure and (2) units which both measure and control a process variable.

Jan 1, 1979

By Elmer W. Pehrson

OPINION seems widely divergent as to where we stand with respect to future mineral supply. From some quarters we hear that the United States is about to become a "have-not" nation and about to experience the evil consequences such a situation would entail. Others claim that we are still a treasure house of stored-up mineral wealth, the surface of which barely has been scratched. The data to be presented here support the conclusion that neither of these viewpoints is correct and that we are far from exhaustion of those mineral resources that are basic to our industrial economy. However, exhaustion is well advanced in a number of important subsidiary minerals so that we can no longer drift along with the easy-going philosophy that the earth will provide. The time has come when we must recognize the true situation and do something about it.

Jan 1, 1945

By W. R. Marks

Computer-aided torsional analysis of grinding mill drives is defined and related to the mill design process. Equations of torsional dynamics are developed for general mechanical drives. Consideration is given three solution types - specifically the determination of undamped natural frequencies, the calculation of steady vibration amplitudes, and the prediction of transient torques during starting. Following a summary of the methods of calculating drive motor performance, the problem in making practical application of this theory are discussed. Experiences in both calculating and measuring the torsional loads on a large ball mill with dual synchronous motors are reviewed. Conclusions are drawn on the effectiveness of computer-aided torsional analysis for improving mill drive reliability.

Jan 1, 1984

By G. H. Fancher

Improving economic conditions are reflected in the statistical picture of the petroleum and natural gas industry for 1933. Prices were better, demand was greater and the volume of production increased. The increase in the production of gas has been due mainly to the utilization of outlets to the new prolific gas fields of Potter and Tioga counties; of oil, to the growing demand for Pennsylvania grade lubricants. It should be emphasized that nowhere is volume of production more subject to control due to the extensive use of secondary methods of recovery and regional peculiarities than in Pennsylvania. A summary of developments in production for Pennsylvania in 1933 of necessity is brief. The data listed in Table 1 are all too few in number and not all that is desirable from the standpoint of accuracy. No state agency for the collection of data exists, no reports are compulsory. Nevertheless, because of the hearty cooperation of many individuals and public spirited corporations, it is believed that the data are as reliable as are obtainable at the present time. Furthermore, records of the past too often are lost, were never in existence or are fragmentary, to say the least. Illustrative of the condition is the fact that no thorough study of the oil and gas-producing regions has ever been made. The publications of the Pennsylvania Topographic and Geologic Survey upon the subject are noteworthy and valuable, especially the most recent one.' The Survey has been handicapped in the work by lack of time, personnel and funds in addition to the difficulties mentioned previously. It is obvious, therefore, that Table 1 cannot be completed for Pennsylvania. The data simply are not in existence. Officially there are 328 oil and gas pools or fields known by name and 58 distinct sands or horizons, one or more of which are productive of oil and gas in the various pools, but reliable data for only three general regions could be assembled.

Jan 1, 1934

By Charles Albert Ashburner

THE stratigraphical geology of the vicinity of Buffalo has always been of great interest on account of its bearing on the origin and history of the Niagara-river gorge, between the Falls and Lake Ontario. Recently, however, the character and thickness of the strata which underlie Buffalo have acquired more practical and economic importance on account of their relation to the possible occurrence of natural gas in commercial quantity near the Niagara river. In a paper presented at the Duluth meeting (l887), on " Petroleum and Natural Gas in New york State" (Trans., xvi., 906), I gave a brief description of the four wells which had been drilled by the Buffalo Cement Company between 1883 and that time. One of these wells is 1305 fret deep; and, at the time that my paper was finally revised for the Transactions (June, 1888), it was still an open question whether the drill in this well had reached the Niagara limestone, or had penetrated the Medina sandstones and shales, which latter are boldly exposed in a number of localities in the district, hut more particularly along the Niagara river in the vicinity of Lewiston and Qneenstown. The difficulty in this geological question at Buffalo has lain in the fact that no reliable determination could be made of the thickness of the strata included between the Corniferous limestone, immediately below which the drilling of the Buffalo gas-wells was commenced, and the Niagara limestone. On the other hand, the strata included between the latter limestone and the middle portion of the Medina sandstones and shales, have been minutely measured and studied in the Niagara gorge below the Falls by many American and European geologists. The first reliable section of these strata was constructed by Professor Eaton, and published in 1824 in his report on the Geological and Agricultural Survey of the District adjoining the Erie Canal. This section, extending from Lake Erie to Lewiston, is complete, with the exception that no thickness is given to the Salina or Onoudaga salt group,

Jan 1, 1889

By W. E. Wickerham

THE Magnetic Storm Monitor is an instrument that continuously records variations in the earth's total magnetic field at a fixed location. It is intended for use in conjunction with airborne magnetometer surveys. There are stormy periods when changes in the earth's magnetic field are so violent that data obtained with airborne equipment would be of little value. The Monitor provides this information so that flights may be cancelled or terminated, thus eliminating useless flying. Moreover, when some unpredictable change in the earth's field occurs during an airborne survey, the Monitor record, showing a similar event, may serve to salvage the data. The utility of a base instrument is determined largely by its physical dimensions, power requirements, stability, and reliability. This instrument is small enough to be transported in any powered vehicle. It will operate from either a 110 v, 60 cycle power line or from an inverter powered by an automobile battery. The development of an electronic feedback circuit that measures the magnetic field strength and a fabricated buckout magnet having essentially zero temperature has contributed to instrument stability and reliability. A tripod supporting the magnetometer head, a chassis housing all electronic components, and an Esterline Angus Recorder comprise the equipment, shown in Fig. 1. The vibrator-type inverter shown is used when a 110 v, 60 cycle power line is inaccessible. Approxi- mately 60 w are required to operate the instrument and the circuit is insensitive to reasonable power line voltage changes or transients. The head unit contains a fluxgate-type magnetometer element and a special magnet mounted on a ceramic structure. Since this magnet is used to buck out most of the earth's field, adjustments are provided for properly positioning the magnet with respect to the element. This assembly is mounted in such a way that the element can be oriented into the total field. Fluxgate Element: The heart of the Storm Monitor is a fluxgate-type magnetometer element. The ability of this unit to detect changes in magnetic fields has been covered at length in the literature.1, 2 For this discussion it will suffice to say that the Gulf

Jan 1, 1956

By Constantine Michalopoulos, Roger C. Van Tassel

Commercial demand for gold in the United States is important. It has a large impact on the total world commercial and overall non-monetary demand. Given the present free market price and our need to import gold, it has a substantial adverse effect upon our international payments position. But, according to most recent estimates, the United States demand is perhaps no more than 20% of the world as a whole. In 1971, United States consumption was estimated at 215.6 tons out of a total of 1,412.1 tons 1. This figure is very close to the 16% figure developed by Consolidated Gold Fields as the average for the years 1968-1970.2 Surveys of both production and use of gold on a world-wide basis are not new. With the bulk of gold production in only a few countries, it has been possible to develop fairly reliable series on gold output. Estimates have been developed on the known reserves of gold and probable output at various prices.3 On the demand side, figures have been somewhat less complete and reliable. The Bank for International Settlements and the Director of the United States Mint have regularly published estimates of commercial use in major industrial countries. The IMF has issued an increasingly comprehensive survey in its Annual Reports. The IMF has attempted to cover all nations-not restricting its efforts to major industrial nations-and has tried to estimate both gold taken for commercial uses (Estimated Industrial and Artistic Use) and for private hoarding. Their method is to begin with data on free world output plus any net sales by the Soviet Union, subtract any additions to world monetary stocks (or add to available supply for any net reductions in world monetary stocks), subtract estimates for commercial demand and have left as a residual an estimate for private hoarding. The method is straightforward and simple but the quality of the data is suspect. Industry sources tend to believe the figures as biased on the low side because of a persistent tendency to underreport gold movements.4

Jan 3, 1974

By V. C. Smith

Reliable and detailed statistical data available for Kentucky, Ohio and West Virginia are the most meager and unsatisfactory of any of the producing states. Detailed histories and statistics are available for only a few pools. The antiquity of these pools, loose nomenclature, particularly where several names are applied to the same pool or various parts of the pool or a new namsed when the pool was rediscovered, made the collection of accurat historical and statistical data almost impossible. So many of the data reported are unreliable that a breakdown by pools or even by counties, until more accurate information is available, would lead to gross errors. Rather than perpetuate inaccuracies, we have endeavored to go to original sources wherever possible, sift these and provide data that may serve as an incentive and basis for future work. The necessity for accurate information is thoroughly recognized by the operators, particularly because of the effect of recent government regulations and request? for data in connection with the preparation of the various codes a pending legislation. Producers, both major operating companies and individuals, . freely given their time and assistance in the compilation of these data. Valuable information was obtained from tax records, rate cases, statistics published by the oil and gas publications and the Bureau of Mines. So many individuals cooperated in the preparation of these data that individual credit cannot be given. Undoubtedly many errors will be found. Some of the data are open to controversy, and many have been omitted in the hope that new information of a more reliable character may become available. Other omissions are due to an inability to contact the proper individuals, many of whom are no longer connected with this industry. Pennsylvania grade crude sold in 1933 for the lowest price since 1895. Gas production could not find sufficient new markets to fill the void left by industrial stagnation. In the gas industry, where the market price is fixed by contract, uncertainty persisted because of impending legislative action affecting both taxes and utility rates. As a result of these factors and a lack of new money, drilling was restricted to a new low. The lifting of proration toward the end of the year in the Pennsylvania

Jan 1, 1934

By Yap Chu-Phay

IN 1923, when the writer began his studies in metallurgy, he came upon an article by Professor Honda on the, Equilibrium Diagram of the Iron-carbon System, 1 which made a profound impression on him. What interested him most was this sentence: "In the recent diagram of the iron-carbon system, the solidus is usually shown as a curve bending considerably downward. But it can be shown by thermodynamics that if the liquidus is straight or slightly curved, the same must also be true for the solidus. Hence, in my constitutional diagram, the lower portion of the solidus is slightly bent upward." Ever since then the writer has been interested in thermodynamics, especially chemical thermodynamics. The applications of thermo-dynamics to the metallic systems have been, in the writer's opinion, sadly neglected, although we continually use the phase rule in our study of equilibria in the liquid and solid states of metallic alloys. Many investigators, among whom may be mentioned Heycock and Neville, and s Honda and his coworkers, have applied the simple Raoult-van't Hoff law of depression of freezing point, mainly to determine the heat of fusion, but no attempt has been made to investigate the applicability of the thermo-dynamic laws of solution (as opposed to the laws of solution derived from other sources) to metallic systems" showing either limited or complete solid solutions. Perhaps the reason for this neglect is that until recently there have been so few reliable data on the solidus, which is much more difficult to determine than the liquidus. The writer has under way at the present time an investigation of a number of systems, the solidi of which have been more or less reliably determined. Recently, the writer has not only shown the valid applicability of the thermodynamic laws of solution as applied to the system antimony-bismuth but has also suggested a method of attacking problems involving complete and incomplete equilibria.2 In the present paper, the same method of approach is employed. For convenience, we shall divide this paper into two parts:

Jan 1, 1931

By L. S. Darken, H. A. Wriedt

THE constitution diagram of the iron-copper system derived by Daniloff' exhibits, at the iron-rich end, phase fields similar to those of the iron-carbon diagram. At 1484° 1094°, and 850°C there are, respectively, a 6-y-L peritectic, a y-E-Lperitectic, and a a-y-E eutectoid. The phase designated E is copper-rich, containing 4 pct Fe or less according to the temperature. The composition of copper-saturated ferrite (a-solid solution) has been determined previously only twice as a function of temperature. By electrical conductivity measurements, Buchholtz and Köster2 found 3.4 pct Cu in ferrite at a eutectoid temperature of 810°C. They represented the composition of saturated ferrite by the equation, log (%Cu) = 4.32-4125 (1/T) Gregg and Daniloff3 reported that Köster later modified his opinion, raising the indicated eutectoid temperature to 833 °C and the copper content of eutectoid ferrite to 3.7 pct. The literature contains several indications4-7 that the work of Köster and his co-workers is not reliable. Norton,8 using an X-ray method, found that 1.4 pct Cu dissolved in ferrite at the approximate eutectoid temperature of 850°C and that the solubility decreased to about 0.3 pct at 700°C. Below 700°C his experimental data show almost no change in solubility. These findings, although inconsistent with the work of Ruer and Goerens4 and of Smith and Palmer,7 have been used generally since their publication. In investigations involving the observation of arrests in temperature during continuous heating or cooling the precise location of the eutectoid temperature has been obscured by a large hysteresis. The more reliable work 579 where the results are not effected by this hysteresis indicates a eutectoid temperature between 840° and 850°C. The foregoing discrepancies, along with a few observations in this Laboratory relating to the precipitation of copper from ferrite, prompted us to rein-vestigate the lower temperature portion of the Fe-Cu system. In this investigation the solubility of copper in ferrite was obtained by the chemical analysis of high-purity iron equilibrated with copper-silver alloys. This method eliminated the necessity for retaining by a quench the physical state of the specimen existing at the equilibration temperature. EXPERIMENTAL The reaction of the iron with the copper alloy was

Jan 1, 1961