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Mr. Address Member is hereby proposed by the undersigned, as a Associate Junior Member of the American Institute of Mining Engineers. Signature of three Members or Associates (not Junior Members). Place of birth Year of birth Education, when, where and how acquired, with degrees, if any. A technical education is not requisite for membership. Dates Please give record of experience on following page with dates; for example, in the form used by "Who's Who In America" and similar publications.

Jan 1, 1918

Mr. Address - Member is hereby proposed by 'the undersigned, as a Associate Junior Member of the American Institute of Mining Engineers. Signature of three Members or Associates (not Junior Members). Place of birth Year of birth Education, when, where and how acquired, with degrees, if any. A technical education is not requisite for membership. Dates . . Please give record of experience on following page with dates; for example, in the form used by "Who's Who In America" and similar publications.

Jan 2, 1918

By H. L. Ames, P. H. Jennings, R. W. Stanley

A process has been developed for leaching copper, lead and calcium from molybdenite concentrate. The leachant is a solution containing an oxidizing chloride (e. g., CuC12, FeC13) and an alkaline earth metal chloride (e. g., CaC12). Cupric chloride and ferric chloride, in the presence of 20-30% calcium chloride, are effective oxidants for chalcopyrite and galena. Calcium chloride, in addition to promoting the rate of leaching, serves to lower the solution pH and raise the boiling point. Leaching for two hours at 110'~ with a 1 % CuC12-10% FeC13- 30% CaC12 solution results in the extraction of up to 98% of the copper in molybdenite, 98% of the lead, and 79% of the calcium. Less than 0. 5% of the molybdenum is dissolved. The leach solution can be rapidly and effectively regenerated with gaseous chlorine and recycled. Build-up of copper and lead in the leach solution is controlled by discarding about 30% of the leach solution each cycle.

Jan 1, 1973

By James H. Boettcher

INTRODUCTION A complex interaction of worldwide economic and political forces is increasingly requiring 3 primary participants for the successful development of large natural resource projects in developing countries. They are the host government of the developing country (the "host government"), one or a consortium of international natural resource companies, (the "Resource Company") and one, or more likely, a syndicate of international lenders. The host government typically controls the rights to its country's natural resources and establishes the economic ground rules for their development. However, because of worldwide inflation and the depletion of easily accessible, high-grade resources, the nominal and real capital development and operating costs of projects have been spiraling. Moreover, the depletion of high-grade and mineralogically uncomplicated resources also raises the technical and operating risks associated with resource recovery. Thus, despite increasing political self-consciousness and economic nationalism in developing countries, international resource companies are still often necessary project sponsors since they can provide, among other things, the required technical and management expertise and equity capital. The presence of these factors, and often the addition of worldwide market access in a project, is often critical in determining whether or not the project will be considered creditworthy by international commercial lenders. The international commercial lender is often the critical third party in project development, due in a large part to the ever escalating-costs of project developments relative to the financial resources of many companies and even a growing number of countries. In addition, lenders have other reasons for taking more than a passive interest in all aspects of a project's development. These reasons include the following: 1. Projects are often financially structured such that the primary security for a loan, once completion and performance standards are met, is the cashflow of the project rather than recourse to its sponsors. 2. Lenders, in addition to the "project risk" just described, are frequently asked to assume various elements of "political" risk which nay put them in a sensitive economic position between the host government and international resource firms (This is discussed later). 3. International banks today have large loan portfolios of developing country debt with final maturities ranging from one to fifteen years. The various current projects undertaken are the building blocks of most developing country economies that will hopefully contribute to the long run economic development of a country as well as generate the foreign exchange necessary to repay foreign loans in the future. In this regard it is useful for lenders to realize whether a given project "makes sense" in terms of a country's natural resource endowments and competitive advantages over other countries. The type of framework discussed in this article would help lenders to better make such assessments. In order to facilitate the continued international flow of capital and technology to developing countries and of readily available supplies of raw materials from them, it is important for each of these three parties to increase its awareness of the goals and objectives of the other parties as well as the bargaining process that results in the legal, financial, credit and fiscal structures by which a joint venture project ultimately proceeds. Each of the parties faces increasingly complicated accept/reject decisions when they are faced with difficult choices among. a wide range of alternative structural combinations each of which has different implications for risk and reward to them. Therefore, by increasing the mutual, 3-way awareness of the decision processes of the other parties, it should be possible to: • provide better information and results in the formation of more rational expectations by all parties going into negotiations, • facilitate the project formulation process by allowing parties to focus more clearly on the areas of common interest and conflict, • result more frequently in final structures and agreements that better reflect the economic and political realities associated with a project and thus • result in more creative, innovative agreements that should reduce the need for changes to them and thus promote the kind of long run political stability conducive to attracting capital and further investment.

Jan 1, 1982

By C. J. McHargue

THE angles between the crystallographic planes in cubic crystals have been given by Bozorth,¹ in magnesium, zinc, and cadmium by Salkovitz,² and in tin by Nicholas. The determination of the orientation of single crystals and the study of plastic deformation require the knowledge of these angles and are often facilitated by use of a standard projection. Tables of these angles and standard projections have not been published for titanium or zirconium which have c/a ratios considerably less than those hexagonal metals for which this data is available. Accordingly, Table I has been prepared giving these angles. Fig. 1 presents a standard (0001) projection of titanium. The angle between (h1k1i1l1) and (h2k2i2l2) was calculated by means of the formula: h1h2 + K1K2 + 1/2 (h1k2 + h2k1 + cos 4 = [(hi2 + K + h1k1 + 3/4 l12 (h2² + C" a² 3/4 — l1 l2 C² k2²+ h2k2 + 3/4 —l2²) ] 1/2 c² The c/a ratio for titanium is taken from the data

Jan 1, 1953

By Robert I. Kingman

SUFFICIENT testing has been performed with the Dutch State Mines Cyclone for thickening and desliming flotation feed at the concentrator of the National Lead Co., Tahawus, N. Y., to prove its application for this work. It is the purpose of this article to present some of the test results, operational details and advantages of cyclone thickening and classification. The metallurgy of the mill operation was described by Frank R. Milliken, assistant manager of the titanium division.l The present flowsheet for the recovery of ilmenite consists in grinding the crushing plant product in four open-end rod mills in closed circuit with mechanically vibrating screens to approximately -20 mesh. The screen undersize is treated in Crockett magnetic separators which produce three products: magnetic concentrate, nonmagnetic tailing containing ilmenite and gangue, and a Crockett slime overflow. The non- magnetic tailing is classified into eight sizer spigots products and a classifier overflow. The spigot sand products are tabled separately to produce a rough ilmenite concentrate, a middling product and a tailing. The table middlings are returned to Crockett feed. The table concentrate is dewatered and dried and further concentrated on Wetherill magnetic separators to produce the finished ilmenite concentrate.

Jan 8, 1950

By J. Landau, A. Dim, R. Houlihan

Recent developments in the application of solvent extraction in hydrometallurgical processing make it desirable to reassess the present state of availability of suitable equipment for these applications. The range of solvent extraction applications now includes very large scale applications with a modest demand on separation performance (the treatment of some base metals) and applications in which the decisive factor is a very high requirement on separation performance. The extraction column to be described in the present paper is of the type in which mechanical energy is provided for the two- liquid system inside the column. The active elements for this are reciprocating sieve plates designed and mounted so as to uniformly load the driving mechanism, to eliminate vibration of the plant, to have sufficient control over the degree of dispersion of the dispersed phase, and to reduce axial mixing effects, which are highly detrimental to the separation performance of production-scale plant. The operating features of the reciprocating-plate column will be illustrated mainly by experimental results obtained on a 4" diameter column in the extraction of uranyl nitrate with TBP. Some mechanical features of the operation of reciprocating-plate columns will also be discussed.

Jan 1, 1973

By R. A. Ronzio, P. B. Queneau, C. A. Born

The molybdenite flotation operation of Climax Molybdenum Co., Division of AMAX Inc., near Leadville, Colo., generates a rougher tailing containing 0.03% W03 and 0.005% SnO2. This tailing is subjected to a series of mineral beneficiation steps for production of wolframite and cassiterite concentrates. However, these byproducts are contaminated by small quantities of UsOa. This paper describes application of sulfuric acid-sodium chlorate leaching for substantial elimination of the radioactive impurities, particularly the mineral brannerite. The leached residue is amenable to magnetic separation of wolframite from cassiterite.

Jan 1, 1976

By George H. K. Schenck

The investment analysis methods that are most generally accepted in the mineral industries in the mid-80's are presented along with their advantages and disadvantages. Also covered are current widely-used practices for introducing the uncertain nature of most of the important variables in an investment analysis, which is contrasted to the former dominance of deterministic analysis. Finally, the discussion turns to current practice for handling the two critical areas: cost of capital and inflation. The advice contained is reinforced with data from a survey of current practices in the petroleum industry.

Jan 1, 1985

By T. Kilner, A. Plumtree

DURING an investigation of electro-deposited silver structures, samples were prepared for metallographic examination by cold mounting in plastic, grinding on successive grades of emery paper down to 3/0, and chemically polishing by swabbing using the chromic acid solution described by Gilpin and Worzala.1 Attempts to etch these samples using the standard solutions described for silver (e.g., 5 pet KCN-5 pet Na2S2O8, H2O2-NH4OH, and various potassium dichro-mate solutions) all failed to give good results due to staining of the samples and to rapid etching. The staining was caused by the chromic acid polishing solution being trapped in small fissures between the sample and the mounting plastic, and also in small fissures in the sample itself. To overcome these difficulties, an etchant was developed which prevented staining at the same time as it slowly etched the sample. This resulted in a very clean, crisply etched surface as shown in Figs. 1 and 2. This etch consisted of 10 ml of orthophosphoric acid, 10 ml of distilled water, and 2 drops of the polishing solution noted above,' which is made by mixing 100 ml of saturated CrO3 solution, 45 ml of 10 pet HC1 solution, and 800 ml of distilled water. The etching procedure involved taking the final polished sample, either immersing or swabbing in the etchant for a period of 1 to 2 min, rinsing as quickly as possible in distilled water, alcohol, and ethyl ether in that order, and then immediately drying. This etch is easily controlled due to its slow rate of etching, and produces samples with clean, sharp surfaces. Pits due to overetching produced varying contrast effects when viewed under polarized light, and are therefore obviously useful for revealing many structural details within the sample. Another effect of overetching was to produce a height varia-

Jan 1, 1968

By T. E. Schmieman, J. E. Miller, M. L. Rizzone

Both centrifugal and reciprocating-type pumps have been widely used in the transport of slurries. Although with some limitations, centrifugal pumps may be used, especially for short-haul systems, however, for the long pipelines the reciprocating pumps are better suited. A state-of-the-art review is presented in which a discussion of applications is made and some of the problems associated with meeting the proper design conditions for satisfactory service are discussed. Several developments underway give considerable promise of better pumps in the future, although the current level of development provides for an economical means to move slurries. The movement of liquids in pipelines necessarily occasions the use of pumps. The petroleum industry is familiar with the transport of solids through mud pumps and cementing and fracturing pumps where the movement of slurries is an everyday matter. In the drilling of an oil well, the circulating fluid utilized to remove drill cuttings is called drilling mud. This substance is usually a fairly sophisticated material designed to develop certain characteristics desirable in the drilling process. The cuttings are suspended in a moving column of this fluid and brought to the surface. The separation of the cuttings from the drilling fluids is accomplished by the use of shaker screens and settling pits; however, it is impractical to remove the cuttings completely and as a result they are pumped through the mud pumps back into the circulating stream. Over the years, mud pumps have been improved so that rather long life can be obtained from liquid end parts subject to the attritional effects of the abrasive-laden fluid. It is from this background that reciprocating-type slurry pumps have been developed. Centrifugal Pumps Centrifugal pumps have also been used to transport solids, where low heads are required, typically up to 200 ft or so, and for short hauls. The centrifugal pump is a hydrokinetic device wherein the increase in velocity of a fluid stream is converted to head, and to achieve high heads a large change in velocity is necessary. Abrasive laden fluids cause wear on impellers and casings as a result of erosion by the fluid and the suspended particles. Centrifugal pumps, therefore, can only be used where the internal velocity of flow is rela- tively low. The advantage of centrifugal pumps is their high capacity at relatively low capital cost and usually relatively small space requirement. One of the disadvantages of the centrifugal pump when used in slurry pipelining can be seen in its typical pressure-volume performance relationship, which tends to work against the application (see Fig. I). If an increase in pressure (head) is occasioned by flow restrictions in the pipeline, say by the dropping out of solids, a desirable characteristic of a slurry pump would be that it develop increased pressure to overcome the restriction. The centrifugal pump provides the increased pressure only at the expense of considerably reduced volume which then results in a lower flow velocity. With the reduced flow rate, adequate velocity to hold the material in suspension and keep it flowing in the line might not be achieved. If centrifugal pumps are considerd for the movement of solids in a long line, a series of pumps must be staged in order to provide the necessary motivating force. A large number of pumps in the line would be required, since each of the pumps could provide only a small pressure increment. An equal number of standby pumps

Jan 1, 1971

The suggestions of the members of the Institute are very much desired by the Committee on Nominations prior to deciding upon its nominations to fill the places of those officers who retire early in 1917. The Committee must make its final report to the Board of Directors early in October. The members are, therefore, asked to send in promptly their .suggestions for Directors as well as for Vice-Presidents and President. The Committee hopes to hear from a large number of the members. The officers to be elected at the annual meeting in February, 1917, are: One officer, known as Director and President. Two officers, known as Director and Vice-President

Jan 8, 1916

By C. Grua, M. Gottlieb, E. M. Wewerka

The Purpose of this paper is to present an overview of research underway at the Los Alamos Scientific Laboratory to investigate some of the more attractive options for controlling trace element contamination of coal refuse drainages. * The control methods under consideration include chemical and physical methods to immobilize or remove undesirable contaminants prior to refuse disposal, the treatment of refuse disposal sites with attenuating agents to prevent the discharge of contaminated water, and the direct treatment of refuse drainage as it emerges from the refuse disposal site. The results from these laboratory studies suggest that many of these techniques are technically feasible for controlling trace element contamination of refuse dump drainage.

Jan 1, 1982

By John M. Hartman

(Read at the Wilkes-Barre Meeting, May, 1877.) Two systems are used for heating air in blast-furnace operations I. The double surface system, in which a cast-iron pipe is heated on the outer surface, and, at the same time, heats the blast from its inner surface. This is simple in operation and gives a continuous effect, but is limited by 1100° F. as a maximum temperature of the blast. II. The single surface system, by which large surfaces of fire-brick are heated, and air passed over the heated surface, absorbing the heat and carrying it on to the furnace. This system is more complex than the double surface, as it involves the reversing of the air and gas every hour and a half. The single surface system has two advantages: 1. The blast can be heated to a temperature of 1800° F. 2. The stoves are indestructible. From recent experience it has been found that 1300° F. to 1400° F. is the best average temperature for economy of coal for safe work¬ing. This is equivalent to a saving of 12 to 2 cwt. of coal per ton, of iron over the extreme limit of cast-iron stoves. Independently of this, it is a strong point in favor of this system that the blast can be raised to a temperature of 1800° F. within an hour when the hearth is getting cold. All furnacemen know the value of a hot hearth for quality and quantity of iron. Cooling of a hearth occurs from leaky tuyeres, scaffolds, or heavy burden. When there is not sufficient coal at the tuyeres to seize on the oxy¬gen of the entering air and convert it at once to carbonic oxide, there will not be enough heat to liquefy the cinder. Black cinder and poor iron are the results. The remedy is additional heat from the blast. If the stoves will give 1800° in place of 1100°, it is obvious that the furnaces will get around sooner, and without waiting for a change of burden at the tunnel head to bring extra coal to the hearth. The heat absorption caused by a leaky tuyere will chill the hearth and drive the zone of fusion higher up in the furnace. This loss must be supplied, and the calories lost to the hearth must be regained before good iron can be made. Take another case : A furnace carefully burdened on No. 1 iron, during a spell of damp weather, goes on to No. 2 or No. 3. Heat is lost to the furnace through absorption by the moisture, and less burden must be carried in order to get back on No. 1. When the

Jan 1, 1878

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 James J. Olson, Richard A. Dick

Blasting practices have shown a recent trend toward larger blastholes and larger burdens and spacings, although some operators, after reconsidering the situation have gone back to smaller blasthole sizes. The greater pull-down capabilities of larger drill rigs and the greater bearing strength of large diameter drill bits give penetration rates for large diameter blastholes approaching, and sometimes exceeding, penetration rates for smaller holes. In practically all cases, large diameter holes can be drilled more quickly and cheaply, based on volume of hole, than small diameter holes. The industry's shift to dry blasting agents and slurries, products which perform more dependably and efficiently in larger diameters, gives an additional advantage to larger boreholes.

Jan 3, 1972

By John Ryan

SIR HUMPHREY DAVY'S epoch-making treatise delivered on Nov. 9, 1815, before the Philosophical Society of London, first announced and demon¬strated a flame safety lamp for detecting methane in mine air. Coal mining was known in England as early as 1180, more than 600 years before the advent of a safe lighting and gas-detecting appliance. Mining, no doubt, took place first in outcrop coal, and danger from gas did not become apparent until the workings became deeper and more extensive. Davy's lamp did much to increase the safety of miners, and a modified Davy lamp is still widely used for detecting the presence and approximate amount of combustible gas in mine air. No factor in coal mining has improved more rapidly during the past 15 years than safety measures. This progress came about not only as a result of the work-men's compensation laws now in force in most of the states of the Union, but because the research work of the U. S. Bureau of Mines has demonstrated some dan¬gers incident to coal mining which were not considered to be serious matters prior to that time. Electric power and explosives are necessary but 1-potential hazards in American coal mines. A general mechanization program is now under way, while the mines are growing deeper and more extensive. Conse-quently ventilation problems are more complex and a demand has been created for positive detecting devices for carbon monoxide as well as methane. Scientists and manufacturers, working hand in hand during the past 10 years, have invented and developed appliances which make systematic and effective examination of mine air possible. The object of this paper is to describe briefly the approved testing devices in use today, with the hope that they may lead to the saving of life. Dangerous coal mine gases may be placed in two groups: (1) those that are dangerous because of their explosive properties, and (2) those that are dangerous because of their toxic properties. Methane (CHI) is the important gas of the first group, and in so-called gaseous mines constantly exudes from the coal and rock; it may accumulate and form an explosive mixture.

Jan 2, 1927

By J. B. Scott, J. S. Nelson, G. H. Kruse, W. S. Johnson, K. L. Zerneke

The economics of pressure tunnel design emphasize the utmost utilization of the least expensive pressure-resisting material available, namely, the rock surrounding the tunnel. A major difficulty in the design is the problem of transferring internal hydraulic pressure to the rock through a tunnel lining or membrane provided to maintain watertight conditions. The lining is necessary not only to prevent water loss, but to prevent the diffusion of water at high pressure through joints and fractures beyond the confines of the tunnel, an occurrence which could ultimately affect the stability of the rock mass through which the tunnel passes. Because of its toughness and ability to bridge localized areas of weakness, steel is used for a lining material whenever high internal pressures are involved. The steel lining is coupled to the surrounding rock mass through an annular ring of concrete backfill. It is paradoxical that the steel lining, needed primarily to assure water tightness, must of necessity be incorporated into the structure as a major pressure-resisting component, not to augment the bearing capacity of the concrete and rock, but to limit the strain for the safety and preservation of the steel lining itself. With the deformation modulus of the steel so much greater than that of the rock, the liner approaches its yield strength before the load capacity of the rock can be fully mobilized. An economical determination of plate thickness for steel liners is therefore dependent upon measurement of the properties of the surround-

Jan 1, 1970

By Walter Wood

The specifications for locomotive-cylinders, which are given in a separate paper at this meeting, have been prepared so that castings (upon the successful use of which so much depends) shall be made to conform to standards that will yield good results. After the essentials, which go with a sound and perfect cauting, the requirements to be borne in mind are those concerning the quality of the material. These have been determined from the actual practice of the largest users,—representatives of the American Locomotive Company, the Baldwin shops, and the Pennsylvania Railroad being upon the Committee. The results called for by the test-bar have been carefully checked by actual experiment upon metal that has given satisfactory service in cylinders.

Jan 1, 1905

By J. E. Campbell, G. D. Calkins, N. M. Ewbank, M. Pobereskin, A. Wesner

GRINDING for size reduction affects the economics of many processes and products. It is essential as the first step in many industrial processes and is also a finishing step for materials with properties depending on particle size, such as talc, cement, and silica sand. Intermediate and fine grinding are vital operations in the U. S. cement industry, which is producing more than 250 million bbl of cement per year.1 Wear of the grinding media is a large part of the grinding operation cost. Problems encountered in grinding cement are so complex that evaluation of efficiency and economy of grinding media is difficult.2 It has been especially difficult to evaluate the relative effectiveness of different types of balls because there are no good testing techniques.

Jan 12, 1957