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By A. T. Yu

As the first year of full-scale shiploading operations nears completion, Chile's twin ports of Chafiaral and Caldera have proved instrumental in promoting the growth of that nation's iron ore industry. Located on the Iron Coast several hundred miles below Antofagasta, the two ports boast of new conveyor shiploading facilities uniquely adapted to their coastal environment. Until recently, iron ore producers in this region of Chile have been hampered by antiquated methods of loading crushed ore on ships for transportation to foreign buyers. Use of the "truck-to-lighter- to-ship" method, which dominated heretofore, was too slow and costly to permit expansion of productive mines and exploitation of new high-grade discoveries to meet the growing world demand for such ore.

Jan 8, 1960

By James E. Dunn

For several years, ground support at the Pitch uranium mine has been a serious headache to the management. The "moving" ground raised havoc with standard timber sets as well as steel sets. The author discusses this problem which has led to the adoption of heavy cribbing practices in drifts and raises.

Jan 6, 1961

BROWN iron ore reserves of Franklin county are being proved economical by Heavy-Media separation at the Blackburn mine of the Shook & Fletcher Supply Co. about 120 miles north-west of Birmingham. The ore occurs under a cover of ferruginous chert and gravel and these materials are also disclosed as streaks in the ore body as it is mined. Previous methods of jigging and hand sorting the ore became too expensive because of rising wages but the use of Heavy-Media separation has proved economical and is making Franklin county the most promising source of additional reserves of brown ore.

Jan 12, 1950

By William H. Hartwig

A paper by Rose1 has called attention to some of the problems of wetting-liquid relative permeability measurement. The premises and conclusions set forth by Rose, namely the applicability of the Hassler scheme of measurement, will be accepted. In addition, it will be concluded that certain electrical analog circuits can be used as a pattern for consideration of possible hydraulic systems of measurements. NEW SCHEME OF MEASUREMENT The object of this note is to propose a new scheme of wetting liquid relative permeability measurement. It is significantly different from those heretofore described, nonetheless it is based on Hassler concepts. The scheme is illustrated in Fig. 1 in terms of the corresponding electric circuit analog. It may be designated descriptively as the "comparison" method of wetting-liquid relative permeability measurement. In this circuit, R, represents the resistance of the core sample which is being studied for relative permeability characteristics, R represents a "standard" resistance, R represents the combined series resistance of the barrier pads, R R2 represent the combined series resistance of barrier pads in the manometer circuit, C, C represent the capacitance of the manometers, E is a constant voltage source, S is the switch or stopcock. The following conditions are imposed upon .the network: Rb » R, and R, R,» R, R, » R., and the condensers C, and C,

Jan 1, 1953

By James A. L. White

Of the natural elemental surfur deposits of the world, volcanic deposits are not only the most spectacular, but probably the most widely distributed. As defined for the purposes of this paper, volcanic sulfur deposits include those associated with all phases of volcanic activity, including eruptive flows, and fumarolic and hot spring deposits. The line of demarcation between the latter and sedimentary deposits is not always clearly defined. Although volcanic sulfur has played an important role for centuries, serving as essentially the only source of sulfur, currently it is considered as purely marginal material. Volcanic deposits were relegated to this position by the advent of Frasch sulfur into world markets, which established sulfur prices and annual production levels with which volcanic sulfur cannot compete, Since early in the 20th century commercial interest in volcanic deposits of sulfur has been high only when premium markets are available. This occurred in the early 1950s and is the case at present. Considerable effort is currently being expended to establish new producers of volcanic sulfur, and to expand current operations or reactivate previous ones.

Jan 6, 1968

By Grant Buma

The purpose of this paper is to present arguments and evidence that there are natural processes at work which tend to minimize the impact of solution mining on the environment. The contaminants have two sources. First are elements which were present in the roll-front deposit in insoluble compounds, for example, uranium in uraninite and coffinite, molybdenum, arsenic, iron, cobalt, nickel, etc. in sulfide minerals, vanadium in micas and clays, etc. Second are elements introduced by the leach liquor. Precipitation of reduced compounds, scavenging of heavy elements and absorption by quartz and clays, can all reduce the amount of heavy elements in solution. If a roll can be demonstrated to be actively precipitating uranium and heavy metal elements, then the presence of precipitants (pyrite and carbon) can be assumed. Criteria for recognizing an active roll are described.

Jan 1, 1979

By Paul L. Cloke, S. R. Titley

Paul L. Cloke (Assistant Professor, Dept. of Geology and Mineralogy, The University of Michigan, Ann Arbor, Mich.) - On examination of the paper by S. R. Titley it appears that several errors have been made, many of them of a fundamental nature. It is the intent of this discussion to point out these mistakes, and, insofar as possible with the data at hand, to correct them. EXPERIMENTAL WORK Ferrimolybdite-Limonite-Water: The results of the experiments described are very difficult to interpret; nevertheless, a correct interpretation is essential as is pointed out subsequently. The difficulties become apparent when reasons are sought for the continuing change of pH after conversion of ferrimolybdite to ferric hydroxide and for the change of pH when -stirring is stopped after a steady value has been reached. In seeking an explanation of this experiment it seemed to this writer that the (temporarily) steady pH values might be due to kinetic rather than equilibrium effects. In this view the steady pH on stirring might be explained as a balance of several reactions proceeding simultaneously. The first of these would be the slow solution of ferrimolybdite,

Jan 1, 1964

By A. J. Lynch

There are two factors which are important in the development of automatic control systems for mineral preparation and concentrating processes. They are the availability of accurate and reliable on-line measuring instruments and an understanding of the effects of important variables on process behaviour. The state of automatic control for the different processes depends on the progress which has been made in these areas and this varies considerably. This is illustrated by discussion of four processes, wet ball milling and hydraulic classification, wet autogenous milling, sulphide flotation and dense medium separation in coal preparation plants. In each case the process characteristics, current control practice and future developments are discussed. Particular problems which have delayed progress are discussed.

Jan 1, 1984

By William Y. Holland, Roger H. Cook

In view of the increasingly widespread deterioration of concrete structures as the result of the interaction of the alkalies sodium and potassium released by hydration of portland cement and susceptible rocks and minerals in aggregates, it is believed that a paper summarizing the geographic distribution of these aggregates will be of interest to producers and users of concrete, concrete products, and concrete-making materials.

Jan 10, 1953

By H. I. Smith

THE technical and safety press have devoted much space in support of or in opposition to the use of booster and auxiliary fans in coal mines. The Mine Safety Board of the U. S. Bureau of Mines has given the matter consideration, and the Mine Ventilation Committee of the A. I. M. E. is now seeking a discussion of the merits and demerits of such fans to guide it in formulating recommendations. In this paper, I will set up some principles on which I believe most engineers will agree and from which we may work toward a decision, though as to what that decision shall be there may be a difference in opinion. Before stating the points on which I believe. there is accord, I will distinguish between booster and auxiliary fans.

Jan 1, 1927

By Fred W. Menzl, Raymond E. Sutton

GABBS, Nev., in Nye County, is 140 miles southeast of Reno and about 31 miles north of the Southern Pacific railroad at Luning. The townsite lies at the eastern edge of Gabbs Valley, and plant and quarry operations are in the foothills of the Paradise Range at elevations from 5000 to 5900 ft. Hard-surfaced roads connect with main U. S. high- ways on the north and south. Historical Background: Brucite, a magnesium hydroxide mineral, was discovered in the Gabbs area in 1927 and magnesite, the magnesium carbonate, was found later on claims originally staked and worked for the tungsten mineral scheelite. The brucite is on a granodiorite contact and the magnesite is usually some distance away from the granodiorite

Jan 7, 1957

By Young C. Kim

Abstract-The use of computer models to design the ultimate open pit limits during feasibility studies as well as during long-range mine planning is becoming an enforced Practice in all types of mining, e.g., ferrous, non-ferrous, and coal. As a result, the state of the art in computerized ultimate pit limit design methodologies and associated computing and optimizing techniques has advanced considerably in recent years. Unfortunately, very little has been published to date regarding the preferred ultimate pit limit design philosophy, i.e., optimizing m satisfying, or regarding the modeling approaches being used for different types of orebodies. This paper reviews the current state of the art in various modeling approaches and optimizing techniques that are in use for different types of deposits, through available literatures and personal communications.

Jan 10, 1978

By J. W. Harden

THE observations here following are the result of an examination made as to the feasibility of extending the South Mountain Railroad from Pine Grove to Waynesborough, and of the commercial value of the ore through which such extension would be made to pass. The road at present built and in operation has a junction with the Cumberland Valley Railroad, half a mile east of Carlisle, and extends southward to Pine Grove, a distance of 176 miles. The extension proposed will add to it near 27 miles, making its total length 44$, more than 23 of which will run through, or in close proximity to, beds of ore. Along the route taken there are a number of openings at which the ore is gotten, of which the Craighead bank, Huntzinger's bank, Lowrey's bank, Wenkoop's bank, the Henry Clay bank, the Fuller

By R. R. Morral, F. M. Krill, K. T. Aust

THE occurrence of twins in aluminum ingots cast under certain conditions has been well established. For instance, Herenguel and Lacombe1,2 have observed a twinned columnar structure in 99.5 and 99.9 pct Al, solidified by continuous or semicontinuous casting. The structure, which they termed "basaltic," appears in the form of elongated crystalline fibers of alternating luster. Herenguel and Lacombe2 found sections of flat crystalline plates composed of twin crystal plates, in which the twin plane (111) and a [I121 direction contained in the twin plane are parallel to the principal heat gradient. This orientation relationship is different from the usual orientation texture observed in cast face-centered cubic metals, where the [100] direction is approximately parallel to the long columnar axes lying in the direction of growth." A large amount of twinning has also been observed by the present authors in semicontinuous cast aluminum of 99.2 pct purity, Fig. 1. Mondolfo4 has suggested that the twinned cast structure forms by a deformation twinning process as the result of uneven cooling stresses within the ingots. This suggestion appears to be inconsistent with the large amount of twinning observed in the semicontinuous cast ingots and with the large difference of dendritic

Jan 1, 1953

By R. B. Sudderth

The recovery of copper by various combinations of processes centered around liquid ion exchange has certainly been accepted as a technically superior entity when compared to the widely applied classical method of cementation. While the technical aspect of liquid ion exchange processes has received much attention and acclaim through actual operating data, in particular the ease of handling solutions, percentage recovery, reduction of pollution, etc., the corresponding economic data has either gone unpublished or has been held confidential. Much of this economic data has now been made available for publication; and with this data, we at General Mills Chemicals, Inc., will attempt to present an accurate economic analysis of some liquid ion exchange plants and an economic comparison between these plants and the typical cementation facility.

Jan 1, 1974

By A. P. Herring, M. Hoover, D. W. Fuerstenau

The dissolution of nickel, copper, and cobalt from five different samples of well-characterized deep sea manganese nodules was measured as a function of temperature, pH, leaching time, and particle size. Nickel, copper, and cobalt extraction each respond to these variables in a different manner. The results of this investigation indicate that copper and nickel can be selectively dissolved from iron and manganese at moderately low pH, provided the reaction is given sufficient time. A high dissolution of cobalt with dilute sulfuric acid can only be achieved from nodules that have a low iron content (<5%). The most probable rate-controlling step for copper and cobalt dissolution is diffusion through the pores of the nodules, and for nickel dissolution chemical reaction appears to be rate-controlling.

Jan 1, 1974

By Julian Kennedy

When it was decided to erect these furnaces the company also decided to use the Cowper type of stoves. It was, however, desirable to improve upon the plan of the stoves then in operation, to avoid, if possible, some defects which had shown themselves in them. The stoves now in use at Furnaces " A," " B," and " C " are of the well-known type of Cowper stove, having a circular combustionchamber placed at one side of the stove, and a regencrator with crescent-shaped section, resting at the bottom oil cast-iron glatings, which are supported in turn by cast-iron girders, the products of combustion passing up the chamber, down through the flues of the regenerator, and thence to the chimney. The objection to this shape of stove, that the gases would not pass down the parts of regenerator lying beside and behind the combustion-chamber—the horns of the crescent, as it were,—did not apply to the newer form of stoves, with combustion-chamber having a straight wall next to the regenerator; but. there were other defects, the principal ones bring the small size of the openings through the regenerator and the material used for supporting it. The small passages (4" X 4") soon choked up, and when a part of them became entirely closed, not only was the effective heating surface greatly diminished, but as the remaining opening were not sufficient to absorb the heat

Jan 1, 1882

By T. P. Harrington, P. G. Doctor, K. A. Prisbrey

Crushing and grinding ore consumes so much energy that it represents a major component of total processing costs. While it has been estimated that only about 0.6% of the total energy expended in grinding is actually used to create new surfaces, accurate measurement of this quantity is difficult. If energy expended in crushing and grinding could be more directly measured, alternatives for increasing efficiency of the processes could be evaluated more effectively. Since the energy intensity associated with rock fracture is related to fracture sonority, it should be possible to use this sound (acoustic emission) to measure the actual energy expended. However, it is difficult to apply this approach because the mill environment is so noisy. To make the approach practical, a method for differentiating acoustic emissions caused by rock fracture from those caused by extraneous noises must be found. Pattern recognition analysis may provide such a method. This paper presents the results of pattern recognition analysis to make two types of differentiations: acoustic emissions caused by crushing two types of minerals (quartz and chrysocolla) and those caused by two extraneous noise sources, and acoustic emissions produced by each mineral.

Jan 1, 1982

By R. V. Ramani, R. D. Zigmond, R. L. Frantz

In this paper, a computer program for determining the capital and operating costs for coal preparation plants is described along with its applications. The logic of the computer program is based upon the results of a survey of existing preparation plants, operators, plant contractors, equipment manufacturers, and consulting firms. This survey provided information on plant performance, order-of-magnitude costs, and costing procedures. Additionally, an extensive cost data file for the major capital equipment in coal preparation plants has been developed. Using the washability data and the computer program out- puts, the cleaning costs per million Btu can be calculated. Details about the program and its applications can be found in a report by the authors (Zigmond et al., 1979).

Jan 1, 1983

By John F. Shaw

The Denver Mining Research Center headquartered at Denver, Colo., is typical of the new research units recently activated as a result of increased emphasis by the U. S. Bureau of Mines on research concerned with metal and nonmetal (except mineral fuels) ore extraction. The Denver Center, together with the recently established Minneapolis Research Center and the Offices of Mining Research at Reno and Spokane, and the older, well-known Applied Physics Research Laboratory at College Park, Md., share the responsibility for the comprehensive mining research program. The Denver Center specializes in two areas of research: (1) The development of engineering principles and mathematical techniques applicable to exploration, development and operational problems in mining, and (2) the study of rock mechanics as applied to ground control. The first area presently includes three categories: research on methods of ore sampling, mine-systems analysis, and applications of statistics to problems of mineral exploration. The second area emphasizes research in two main categories: laboratory investigations designed to develop a fuller understanding of how rock be- haves under the loads imposed by mining, and field investigations to evaluate stress-strength relation- ships in full-scale, operating mines.

Jan 3, 1962