Search Documents

By Kirtley F. Mather

FROM almost every point of view, petroleum was "strategic mineral number one" during the World War that ended in 1945. Even the spectacular advent of the atomic bomb in the final days of the conflict did not displace it from its position of prime importance, although within a few years uranium will almost certainly be the "number one" material in the minds of military strategists, if it is not even now in that position. But both as fuel and as raw material for chemical industries, petroleum will hold the center of the stage for many years to come. Hardly any other substance illustrates so fully the manner in which science and technology may be combined to achieve the utmost success in contributing to human efficiency and comfort. Fundamental to any understanding of the problems implied by my topic

Jan 1, 1948

By J. Chupak, D. J. Salley, G. L. Simard

Radiotracers were demonstrated to be of considerable value in a study of the interaction of dithiophosphate with galena. The interaction had characteristics of both chemisorption and chemical reaction, being complex because of the nature of the galena surface. Sorption was rapid and markedly reversible, and flotation occurred at relatively small amounts of dithiophosphate sorbed.

Jan 1, 1950

By F. C. Canney

Geochemical prospecting seeks hidden mineral deposits by sampling for variations in the chemical composition of naturally occurring materials. Usually the samples are of soils and other products of weathering and erosion—surface materials extremely susceptible to contamination by human activities. Except when a survey is conducted well away from populated areas, contamination is an ever-present hazard. The program's success is particularly endangered when the contaminants are the elements sought; if these occur erratically throughout an area, spurious anomalies completely unrelated to mineralized areas can be formed. Evenly distributed contamination can be dangerous too, if it raises the background to such a level that true anomalies can no longer be easily detected. Suppose, for example, that in an area where the lead background is 20 parts per million the soil over a lead vein contains 1000 ppm of lead. Here the contrast would be 50 to 1, which is very satisfactory for geochemical surveying. Now if 1000 ppm of lead from some source were added evenly to the soil in this area, the contrast would be reduced to about 2 to 1, and the anomaly would no longer be readily detectable because a threshold of significance twice the value of the background is the minimum generally used for interpreting geochemical data. Of the many possible sources of contamination, probably most important are smelter fumes, which may distribute large quantities of metal contaminants over many square miles of ground. For several reasons, the investigation reported here was begun in the Coeur d'Alene district in northern Idaho: 1) a lead smelter has been operated in this district since 1917 and an electrolytic zinc plant since 1928, and presumably the contamination patterns are strongly developed; 2) to evaluate the usefulness of certain geochemical techniques, V. C. Kennedy and S. W. Hobbs of the USGS had already studied the distribution of copper, lead, and zinc in the soils (both in background areas and other veins) and in the water and plants, providing a criterion for measuring the magnitude and effect of soil contamination; 3) one of the economically important parts of the district lies south of the South Fork of Coeur d'Alene River and within a radius of five miles of the reduction plants near Smelterville (Fig. 1). In this area, and in the entire district, conventional methods of prospecting are hindered by heavy vegetation and thick soil cover, and the possibility of contamination by smelter fumes has discouraged geochemical prospecting. Should data reveal that geochemical prospecting could be done successfully in such an area, a particularly useful tool would be available to mining companies and prospectors searching for concealed orebodies in this economically important part of the district. The field work on which this report is based was done from July 28 to 31, 1955. It should be emphasized that this was reconnaissance study only, and therefore far from exhaustive. Previous Investigations in U. S. : The first geochemical survey known to have been affected by contamination was conducted in 1940—a geobotan-ical reconnaissance made in the Michigan copper district by a private company. Geologists found striking variations in the copper content of oak and maple leaves, but unfortunately the high copper isograds of the study seemed to be related more to the Calumet and Hecla copper smelter fall-out than to mineralized ground.' The leaves of one oak tree near the smelter contained 0.4 pct Cu. Similar contamination was reported by Clarke (Ref. 2, p. 41), who conducted experimental geochemical soil and botanical surveys at Ray, Ariz. He found that the leaves of oak trees growing in unmineralized ground near Superior, Ariz., contained more copper than the leaves of oak trees growing on the capping of the Ray orebody and attributed this fact to contamination from the fumes of the Magma smelter at Superior. According to H. E. Hawkes,3 soils and stream sediments in the Superior area are also severely contaminated. Hawkes' work there has shown a copper content averaging 0.5 pct in the surface horizons of soils within one mile of the smelter stack. Samples taken only a few inches below the anomalous surface samples showed only background copper values. In 1950 L. C. Huff' of the USGS made a geochemical survey in an area near Jerome, Ariz., and found considerable zinc and copper in the soils over unmineralized basalt close to Clarkedale, Ariz., and over limestone close to Jerome. As the amounts were notably greater than could reasonably be expected to be derived from the underlying rocks, Huff suspected airborne contamination from the smelter at Clarkedale. Description of Area: The area sampled in detail (Fig. 1) for the study presented here is one of strong relief. The dominant watercourse is the westward-flowing South Fork of the Coeur d'Alene River. East of Kellogg the South Fork flows in a rather narrow canyon, but its valley floor widens considerably to the west where much of the flood plain is covered by an extensive veneer of mining, milling, and smelting debris. South of the South Fork and between Big Creek and Pine Creek is a mountainous area where

Jan 1, 1960

By AIME AIME

AMONG the European nations Germany is the center of interest economically as well as politically, and of prime importance for Europe as a whole is Germany's capacity to produce mineral products for armament and for export in exchange for the import of the essential supplies to maintain its industries. So far as minerals are concerned, Germany is worse off than any other great power except Italy, and deficiencies are being met by attempts to increase output from local deposits and by greater use of substitutes derived from domestic raw materials to replace imported metals, petroleum products, and other minerals.

Jan 1, 1939

By N. H. Mannakee

SINCE the publication of the paper of Mr. Scholz, The Effect of Humidity on Mine-Explosions,' I have undertaken a study of the meager available data of barometric and temperature conditions it times of mine-explosions, and have arranged these data in a manner which may be of interest to other students of mine-explosions. This study covers the period from 1898 to 1909, during which an ever-increasing percentage of collieries has been ventilated by fans giving air-currents of high efficiency. Previous to 1898 this percentage was smaller than at any time since. The vari¬ous States have become, from time to time, more exacting in their demands upon poorly-ventilated mines. This general im¬provement in ventilation throughout the Appalachian field has undoubtedly brought about a condition which is annually the cause; .or a very important attendant, of the high percentage of fatalities in mine-explosions, through the daily passage of from hundreds to thousands of gallons of water, invisibly suspended in the air, carried out of the mines by the ventilating-currents during the existence of certain temperature- and humidity-conditions. There is a wide-spread opinion that these conditions exist from November 1 to March 31; but it is more likely that they have a much wider range, which varies from year to year. Certain years show an increase or decrease of rain-fall from the mean ; the daily temperature may fall far below or rise far above the mean established by a record of a period of years; and the daily humidity varies likewise. If mine-explosions are influenced by a lack of moisture in the mines, certainly it may be expected that the influence will be felt at times when the

Nov 1, 1909

By DIFTIGIHT E. WOODBRIDGE

(Glen Summit Meeting, June, 1911,) DURING April, May, and June, 1910, I was in charge of an examination of the greater part of the Moa iron-ore area in Oriente Province, Cuba, on the north coast, near the east end of the island. My instructions, on arrival at the properties, were to check former estimates of tonnages and grades, and to re-examine the ore comprised in claims covering 44,727 acres. This work included .the running of lines dividing the properties into co-ordinate planes, the boring of many thousand feet of holes spaced at the intersections of these co-ordinates, the taking of samples of the ore penetrated, the analysis of these samples for their various constituent minerals, and the determination of the results as to tonnages, depths, and grades, both for individual properties and for the entire group. Each section of every one of the thousand holes drilled was to be compensated for depth and grade with every other, a series of simple arithmetical calculations of no slight magnitude, the mere mechanical labor of which consumed much time, but finally resulted in giving a complete average of all the essential facts for the entire area of 18,000 hectares. Had it not been for the more than willing, active, and able co-operation of the officers of the Spanish-American Iron Co., from Charles F. Rand, President, and Jennings S. Cox, General Manager, down to the most humble water-carrier, the work would have consumed far more time than it did. Papers prepared by others, and to which my present paper may be considered an addendum, elucidate, more fully than I could hope to do, the origin and geological character of these ores. I will confine myself to the situation, method and expense of exploration, and to probable courses of development and mining, with some attention to the cost of the ore delivered in the United States.

Mar 1, 1911

By Clark A. Sumner, D. Arthur Burnham

A process for recovery of greater than 99% of the copper contained in acid leach solutions by sulfide precipitation using hydrogen sulfide as a hydrometallurgical reagent has been developed. The process incorporates the concept of hydrogen sulfide addition to recycled copper sulfide solids in a turbulent flow area where further precipitation or agglomeration occurs to increase the effective particle size of the copper sulfide precipitate. Because the recycled solids provide a larger number of particles upon which momentary excesses of hydrogen sulfide are absorbed, oversulfidization of the product is prevented. Copper sulfide precipitates produced in this manner in a laboratory test reactor showed greatly improved physical characteristics compared to copper sulfide precipitates obtained by conventional direct precipitation in which H2S is bubbled directly into acid leach liquor. Copper sulfide precipitates were evaluated and compared by use of filtration tests and settling rate studies. Electron microscopic examination of the solids confirmed the presence of larger particles in reactor-precipitated copper sulfide. Flotation was examined as an alternative to filtration for recovery of CuS precipitates and was found to achieve complete CuS removal without addition of collector or frothing reagents in a period of 2 min. In the same test reactor, a rapidly floatable CuS precipitate was also formed by mixing H2S with acid liquors used to leach crushed copper oxide-copper sulfide ore (LPF process). In the presence of gangue from the crushed ore, flotation of both natural and reactor-produced copper sulfides resulted in recovery of better than 90% of the copper contained in the crushed ore.

Jan 1, 1974

By Carl F. Dietz

(New York Meeting, February, 1912.) THE problem of drying ores is one that most mill-engineers are sooner or later called upon to meet, and it may be timely to point out sortie of the difficulties resulting from such operations from purely a metallurgical and economic stand-point. We mean, in the following pages, to discuss primarily the effect of such operations on. the ore itself, without particular reference to the mechanical or cost features of the subject; That an appreciable tonnage of the ore fed to the usual form of drier, either rotary or stack, is lost, is fairly well appreciated, but we believe that only a few mill-managers know just. what their drier-losses amount to, and we have found that in most cases they console themselves with the fact that the drier-smoke is not very much discolored, and it is generally believed that the draft is not sufficient to carry away more than a. negligible percentage of the values. The drying of ores is becoming an important factor. since the more general application of magnetic, static, and dry-table treatment. Its importance in the field of metallurgical operations warrants a close examination into its effects. This subject has been repeatedly brought hone to us, and while the drier-losses, in every case examined, have considerably exceeded even the most generous estimate, an attempt at a recovery of these values is rarely made. We have found that the losses resulting from drying-operations can be effectively recovered, at a low cost, and believe that the publication of the results of a number of investigations along these lines will be of interest and benefit to the profession at large. To dry an ore quickly and effectively, it must be brought into actual contact with hot gases or air. The rapid drying is effected by the fact that the hotter the gas the hungrier it is

Jul 1, 1912

By Robert F. Mehl

Jan 1, 1944

By Robert F. Mehl

Jan 1, 1944

By E. H. Rose

IN a year of sober reflection and stocktaking after the mineral-squandering spree of World War II, the role that beneficiation of low-grade must henceforth play in American mineral industry has become unmistakable. From the volume of research and development progress in mineral engineering during 1946, mineral dressers evidently have ample resoluteness to meet the challenge. Perhaps ,the most conspicuous trend of the year was the renascence of interest in gravity concentrating methods and more serious effort than ever before to make them effective in finer size ranges down to 200 mesh. This has been forced by the problem in iron ores where the low value of the product will not support a high flotation reagent cost, however good flotation pilot plant results may have been and however well the acute problem of variable feed may be met. The race is on between rabbit flotation and tortoise gravity methods and a surprising amount of betting money is being laid on the tortoise which already is showing previously unsuspected talent for speed. Mostly, however, a wait-and-see attitude prevails during the present preliminary heats. As evidence of the latter, two magnetic plants are now on the boards for magnetic taconites on the eastern Mesabi to establish a reprieve against the time when nonmagnetic taconites must be addressed. Incidentally, these operations will force the blast-furnace issue on preparation of fine material since a minus-100-mesh grind is contemplated.

Jan 1, 1947

By Marius R. Campbell

VARIOUS classes of coals are recognized in this country at the present time. These classes depend largely upon physical characteristics rather than upon chemical composition, and consequently they cannot be accurately defined. The divisions into anthracite, semi-anthracite and semi-bituminous are fairly satisfactory; but the term bituminous embraces so large a variety of coal that it is of little value, and the term lignite is so loosely applied that it has little or no place in a scientific classification. At present there is no way of accurately defining the vari¬ous classes of coal, because no adequate scheme of classification, which applies to lignites as well as bituminous coal and anthracite bas been proposed. The object of this paper is to present such a scheme, which is based upon data obtained dur¬ing the past year by Prof. N. W. Lord,1 in charge of the chemical laboratory of the United States Geological Survey coal-testing plant at the Louisiana Purchase Exposition, St. Louis. All the classifications of coals proposed prior to 1877 were based either on physical characteristics or on proximate analyses, including all of the impurities. These schemes were illogical and highly unsatisfactory, for the physical properties of a coal give little indication of its true composition; and impurities, such as ash and sulphur, are largely the results of acci-

Sep 1, 1905

By H. A. Wheeler

IT may surprise some of our members to learn, among the industries based on the mineral resources of the United States that of clay now ranks third, being exceeded in value of product only by pig-iron and coal. The present annual value of clay-products exceeds the value of the outputs of gold and silver, and also exceeds the combined values of copper, lead, zinc, aluminum, mercury, antimony and nickel. These facts are shown in Table I. which gives the statistics for the year 1902

Jan 1, 1905

By Paul M. Tyler

ROUGHLY one-half the value of mineral products at mines or quarries must be spent for wages. In view of the steady increase in hourly wages that continued for several decades prior to the onslaught of the recent depression, it is perhaps surprising to discover that labor's share of the gross proceeds of the mining and quarrying industries of the United States declined to 46.8 per cent in 1929, compared with 52.2 per cent in 1919 and 53.2 per cent in 1909. The actual percentages vary in different branches of the industry and in different localities but the downward trend is unmistakable. For the period 1909 to 1919 it was quite marked in every industry and from 1919 to 1929 it was apparent in all but six: namely, gold and silver lode mining, placer gold mining, crude gypsum production, marble quarrying, asbestos production, and fluorspar Tninino mining

Jan 1, 1933

By W. L. Honnold

AS BOTH South Africa and diamond mining are unfamiliar subjects it seems best that on such an occasion as this I should endeavor to reflect the atmosphere of the place and to picture the mines from an industrial rather than from a technical standpoint and, because of long absence, my remarks must necessarily be sketchy and in some particulars not up to date. The preferable route to South Africa is via England, direct steamers from America being inferior as to service and effecting no saving of time. The newer boats are of about 20,000 tons capacity and very comfortable. Seventeen days are required for the voyage and only one stop is made-that at the island of Madiera, three days out. Between Southampton, the port of departure, and Madiera the weather may be warm or cold and the

Jan 1, 1925

By Charles G. Maier

SCIENCE beginning in rational observation came of age, when its devotees first began to measure and count. It has been said that the most striking aspect, of science today is its growing abstraction, and its preoccupation with mathematical symbolism. Technology with specific and concrete objectives in the satisfaction of human wants, cannot conceivably achieve the abstract unification that science seeks, but .the utility of the' scientist's method has been too well proved to require bolstering. Metallurgy is in its scientific infancy.

Jan 1, 1931

By M. E. Lombardi

IN comparison with the mining industry the petroleum industry is new and inexperienced, and until now it might have been called the fortunate industry. Its great good fortune consisted in two things; a bountiful supply hidden by nature in the rocks of the earth, and a steady and large increase, during the past twenty-five years, in the demand for petroleum products. It is a remarkable fact that consumption of gasoline in the United States has shown an increase every year since automobiles first became important, and even in 1930 there was a four per cent increase, in spite of the universal depression; the estimated increase if the times had been normal, was ten per cent. This industry has, therefore, not passed

Jan 1, 1931

By H. OSBORG

THE patent literature of alloys for the last two decades or so indicates that the number of liatents referring to smaller and smaller percentages of essential alloying constituents is on the increase, whereas the number of patents relating to considerable percentages of alloying additions becomes smaller. The claims regarding physical properties indicate consistently higher and more rigid values and show the possibility of modifying the physical properties by only slight changes in the percentage of minor constituents or by applying different methods - of treatment. Alloys of the same base have been made suitable for a number of different applications by intelligently and rigid- ly controlling their composition, melting, casting, working, and heat-treatments. Other trends indicated in the development of modern alloys are higher corrosion resistance, higher fatigue limits, and "stability" in volume.

Jan 1, 1937

By G. B. Walker

THE sink-float methods designated by heavy-media separation processes were pioneered by C. Erb Weunsch for the treatment of base metal ores as an improvement over jigs. The work of Weunsch was further developed by Victor Rakowsky and The American Zinc, Lead and Smelting Co. Early in the development of the processes, the inherent unsuitability of galena as the solid constituent of the medium was recognized and ferrous media amenable to magnetic recovery and control were developed. The high efficiency and low cost of magnetic recovery and cleaning of ferrous media regardless of particle size, slime contamination, or surfacial oxidation had led to the adoption of ferrous media by all of the sink-float plants operating under the heavy-media separation processes patents controlled by American Zinc, Lead and Smelting Co. Approximately 2,000,000 tons of base metal and nonmetallic minerals are treated each month by these methods.

Jan 1, 1949

By E. E. White

(Cleveland Meeting, October, 1912.) IN, August, 1911, I read a paper before the Lake Superior Mining Institute' on surveying and sampling diamond-drill holes. The present paper gives a more thorough description of these methods, together with a few changes and notes suggested by further experience. Since August, 1911, the methods, used constantly by the Cleveland-Cliffs Iron Co., have been developed to a higher degree of efficiency, and have given great satisfaction. Until a few years ago but little attention was paid to the determination of the actual course of drill-holes, to the accurate sampling and analysis of the material, or to the scientific location of the drill-holes. It has now been common practice for several years in many districts to test the inclination of drill-holes by etching glass tubes with hydrofluoric acid, but the direction of deviation from the vertical has not often been determined. Methods of determining the direction by means of a compass were first developed in connection with drilling in Victoria. The latest method used on the Rand in South Africa has been recently described by John I. Hoffman.2 In the same paper Mr. Hoffman describes an ingenious method of wedging-off a drill-bole so as to start new holes at several successive points. By this means a hole can be deflected in any desired direction, and the curvature can be controlled to a considerable extent, provided the rock is soft enough to permit the hole to be wedged off. Unfortunately, in the Lake Superior district, the jasper iron-formation is so hard that it is very difficult, if not impossible, to do this. I tried to deflect one hole so as to avoid drill-rods stuck in the hole, by using a 1 Proceedings of the Lake Superior Mining Institute, vol. xvi., pp. 100 to 120 (1911). 2 Recent Practice in Diamond-Drilling and Borehole Surveying, Bulletin No. 91, Institution of Mining and Metallurgy (Apr.. 11, 1912).

Nov 1, 1912