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By Eugene H. Cowles

The German silver industry of the United States amounts in value to upwards of $6,000,000 or $8,000,000 annually. Several thousands of people earn a livelihood pursuing it, and the beautiful goods and articles manufactured from this time-honored and valued alloy are everywhere visible. German silver enters largely into our street signs, harness and house hardware, and all manner of table-ware, solid or plated. There is scarcely an hour in the day that German or nickel-silver is not before our eyes. The composition of this alloy is a very uncertain thing, and depends largely on the honesty of the manufacturer and the price the purchaser is willing to pay. It is composed of copper, zinc and nickel in varying proportions. The best varieties contain from 18 to 25 per cent. of nickel, and from 20 to 30 per cent. of zinc, the remainder being copper. The more expensive nickel-silver contains from 25 to 33 per cent. of nickel, and from 75 to 66 per cent. of copper. The nickel is used as a whitening element; it also strengthens the alloy and renders it harder and more non-corrodible than the brass made without it, of copper and zinc. Moreover, it reduces the odor emanating from brass, which is so disagreeable if it occurs about the dining-table. Of all troublesome alloys to handle in the foundry or rollingmill, German silver is the worst. It is unmanageable and refractory at every step in its transition from the crude elements into rods, sheets or wire. As a white-headed furnace-man recently said to the writer, in one of our large mills, " you can put eight crucibles into the fire, each containing exactly the same mixture of German silver, and when you take them out and pour them into slabs for rolling, seven will be a mass of scum or slag, or the stuff will swell up like rising bread and overflow the moulds, and be so full of blow-holes that it will look like a sponge. The eighth crucible will contain perfectly good metal. On remelting the next day, the bad stuff will, in nine chances out of ten, come out just as good metal as the eighth pot the day before, and under apparently the same conditions." With nickel at seventy or eighty cents per pound, German silver

Jan 1, 1890

By Wallace E. Pratt

UNDER the stimulus of war psychology the American public has grown confused and jittery in its thinking on the subject of this nation's petroleum resources. This confusion arises from the failure of the average citizen, and even of many leaders in government, in our armed forces, and in the petroleum industry itself, to distinguish between our proved reserves of petroleum in the several oil-producing states and the total petroleum re- sources available to this nation. Leaders and public alike examine the accepted estimates of our proved reserves and thoughtlessly conclude that these estimates represent the total of our petroleum resources. Our fears are aggravated if we turn to the statistics on oil-finding and observe that the discovery of new reserves has waned decidedly in recent years. This confusion is dangerous because, under its influence, ill - considered policies spring up and flourish, choking out the most valuable fruits of the long experience of the American petroleum industry.

Jan 1, 1944

By Paul T. Benson

MOST important of the various departments of a custom smelter, so far as the financial welfare of the plant and the confidence of shippers are concerned, is that responsible for correct weights, accurate moisture sampling, and the obtaining of control samples that are strictly representative of the lot of ore from which they come. Treatment rate schedules are based on the metal content of ores received, reduced to dry weight. These rates must be low enough to keep the ship- per from taking his business else- where and still must allow the smelter a profit. Assay results, likewise, must satisfy the shipper, but if they show too high a metal content for the ore they represent, the smelter will actually lose money. It is always considered, and constant checks through umpire assays prove, that laboratory results are closely correct, so the bur- den of the plant profit and loss and the satisfaction of the shipper rest squarely upon the sampling department.

Jan 1, 1936

By H. LIVINGSTONE LMAN

A GOOD DEAL of information concerning flotation has come out during the patent litigation of recent years, and the legal situation has cleared considerably, to the satisfaction of Minerals Separation, Limited. Hence, Mr. H. Livingstone Sulman, one of the originators of the successful process of that company, felt at liberty to explain, on Thursday, Nov. 20, his experience and his views in a "Contribution to the Study of Flotation," before the Institution of Mining and Metallurgy. He did not give technical details. He dealt with the physical problems, so simple, as he remarked, that he had wanted 96 pages to express his views. He presented much data, partly new and based on observations of his own, bearing upon the very complex flotation phenomena in an instructive wav and made frequent references to the valuable researches especially of Prof. Edwin Edser and Mr. Emil Hatschek.

Jan 1, 1920

By ELLSIVOKTH DAGGETT

THE Berlin gold quartz mine is situated in Nye county, Nevada, on the west flank of the Shoshone range, about 40 miles south and 30 miles west from the town of Austin, the county-seat of Lander county. The distance from Austin is about 60 miles by stage-road. The outcrop of the vein, at the top of the incline-shaft, is situated just at the base of the mountain proper, almost exactly at the intersection of the mountain-side with the gravelly bench that slopes for about three-quarters of a mile to the flatter sage-brush plain, or desert valley, below. The -vein itself consists almost entirely of quartz, with perhaps 2 per cent. of sulphide of iron, copper, lead, zinc and antimony, and perhaps a trace of some of the compounds of tellurium with gold and silver, although none of the latter have been as yet positively identified. The relative proportion, by weight, of silver and gold in the ores, varies in different parts of the vein, from 12 silver for 1 of gold, to 7 silver for 1 of gold. The quartz vein-filling is usually frozen fast to the walls, and is very hard and compact, seldom showing the friable, fissured, or shelly structure often to be found in quartz veins. Comparatively little evidence of relative motion of one wall of the vein upon the other is to be found-a fact indicating that during the formation of the vein, and prior to the extensive movements herein described, little disturbance had taken place. No evidence whatever of metasomatic origin has been observed. On the other hand, occasional occurrences of comby structure, in which the axes of the quartz crystals are at right angles to the plane of the vein, rather indicate deposition from solution in a pre-existing fissure. Spurs, or branches, and small parallel veins, while not en-\

Mar 1, 1907

A record $19.7 billion in minerals was produced by United States industries in 1963. This was some $800 million above the previous high established in 1962. Preliminary statistics compiled by the U.S. Bureau of Mines show that most metals, nonmetals, and fuels gained both in value and volume of production. The 1963 total represents the largest value increase since 1956 and continues an upward trend begun in 1959. Product.ion and value of all mineral fuels rose, with anthracite registering a remarkable 20% value increase. Nonmetals advanced 591 in value, gains exceeding losses by 213 to 1 among individual commodities. Heavier industrial demand and the settling of labor difficulties were among the factors contributing to increased output of such materials as iron ore, bauxite, molybdenum, lead, and zinc, which accounted for most in€ the growth in metal output. Silver prices continued to rise and, as a result, production value of that metal gained 132,.

Jan 2, 1964

By Willard P. Ward

SOME TIME in the year 1874 or 1875, I conceived the idea that spiegeleisen might be made -in a blast furnace from ores that were not carbonates, and which did not contain both manganese and iron in the same ore. Up to this time, such ores had formed the basis of all the spiegel that had been produced; and all the ferromanganese that was on the market before 1875 was made in crucibles, and cost about 00 per ton, for 80 per cent. Mn. I consulted the great steel metallurgist of the day, Alexander Holley, who listened attentively to what I had to say, and told me he did not think my plan was practical, so I abandoned it for the time being. But I was so stubborn that I could not get the notion out of my head. It seemed to me that a good metallurgist should be able to work the thing out in some way. I had already had some experience in smelting refractory lead ores in Utah, and was young and not lacking in self confidence, so after waiting a bit, I got Anton Eilers, the best all-around metallurgist I knew, and J. H. Bramwell, the best iron blast-furnace man I knew, both intimate friends of -mine, to come to my place in Bartow County, Georgia, and look over things. They remained for several days, and made all the examination they thought necessary; and they also advised me to give up the project, and either to keep the furnace running on car-wheel iron or to blow it out. After my talk with Holley, I improved my plant in several ways. I closed the top of the furnace, put in a hot-blast stove, a steam boiler and a Weimer blowing-engine which gave me blast enough, at a pressure high enough for all the requirements of, the furnace, and which I could bring up to a temperature of 600° to 700° F.

Jan 1, 1921

By Lyon F. Terry

SPEED-UP of production of crude oil and its products, accompanied by rising prices and the organization of the industry on a war basis, featured the economic aspects of petroleum in 1941. Early in the year American tankers were urgently requested by the British to replace losses and offset slower transit under convoy. Some forty American owned tankers were first assigned to Britain and an additional forty-odd ships were transferred during the summer. This threatened to reduce our transportation facilities from Gulf ports to the Eastern seaboard below requirements, especially should sinkings have increased and the British needed more ships. Co-ordinator Ickes began preparations for restricting gasoline consumption in the Eastern district and plans were formulated for the construction of an emergency trunk pipe line from Texas to New York and Philadelphia refining centers, and for a gigantic tanker-building program. Sales of new oil-heating units in the East practically ceased. The companies were urged to transport as much oil as possible by tank car and by October 140,000 barrels of oil per day were reaching the East Coast district by rail, sufficient to meet 8 per cent of total requirements. But British sinkings from July through October decreased 63 per cent compared with the four months ended June 30, Britain began the return of tankers, the construction plans were dropped, and the threatened shortage was thus averted.

Jan 1, 1942

By H. J. Ramey, I. S. Bousaid

Experimental results on the oxidation reaction kinetics in the forward combustion oil recovery process are presented. A total of 48 runs were made wherein a stationary thin layer of coked, unconsoli-dated sand was burned isothermally in a combustion cell. Individual runs were made at various temperature levels to permit determination of the effect of temperature upon the reaction. An expression was obtained for the burning rate of carbon as a function of carbon concentration, combustion temperature and oxygen partial pressure. The carbon burning rate for two types of crude oil indicated a first order reaction with respect to both carbon concentration and oxygen partial pressure. The effect of combustion temperature on the reaction rate constant matched the Arrhenius equation. The activation energy was similar for the two crude oils examined. The activation energy decreased for a porous media containing clay. The rate of oxidation of crude oil at reservoir temperature was found to be significant. Other significant findings included information on hydrogen-carbon content of fuel residues, fuel reactivity and the products of combustion. INTRODUCTION The production of crude oil by underground combustion has been studied in the laboratory by many investigators.1-5 Results of laboratory and field experiments have been reported in the literature describing the forward combustion process. But as yet, no qualitative or quantitative study of the kinetics of fuel combustion involved in this process has been reported. The fuel concentration and the rate at which fuel is burned at the front are important factors governing the air requirement in a forward combustion operation. Although the fuel is essentially unrecoverable crude, the air required to burn the fuel is an important economic factor in this process. Because fuel is burned, the heat transport associated with forward combustion is a key and unique feature of this new oil recovery method. Many investiga-tors5-9 have presented information on the heat transmission and fluid mechanics involved in forward combustion. Berry and Parrish10 demonstrated the utility of considering reaction kinetics in reverse burning. From differential thermal analysis, Tadema11 presented a qualitative discussion of the nature of reactions between oil and oxygen in combustion oil recovery. Although little quantitative work has been done on the reaction kinetics involved in forward combustion oil recovery, an extensive literature does exist on combustion of carbons and oils, and carbonaceous residues from cracking catalyst pellets. Dart, et al., 12 studied the combustion rate for oxidation of carbonaceous residues on clay catalyst pellets, and found the reaction to be second-order with respect to carbon concentration, and first-order with respect to oxygen partial pressure for carbon concentrations less than 2 weight percent of the catalyst weight. The reaction appeared to be first-order with respect to carbon concentration for concentrations greater than 2 percent. Metcalfe13 noted that other workers had found that aging of the fuel during the combustion process was responsible for changing coke properties, and it accounted for the apparent second-order carbon concentration effect found by Dart, et al. It appears that burning of residues from cracking pellets is first-order with respect to both carbon concentration and oxygen partial pressure. Dart, et al., also observed that hydrogen in the hydrocarbon residue appeared to react faster than the carbon. Lewis, et al.,14 studied oxidation of charcoal, coke and graphite in a fluidized bed. Gas velocities were high enough to partially lift and circulate the carbon particles. Their results indicated first-order reaction dependency with respect to both carbon concentration and oxygen partial pressure. One

Jan 1, 1969

By C. C. Harris

This article presents a general equation describing the xYt surface in batch grinding. This equation contains as special cases most of the relationships which have been deduced from kinetic studies. In an earlier paper an analytical solution of the integro-differential equation of batch grinding was proposed1 as a first approximation of the xYt surface.' A more general equation will be presented here, which appears to combine in a single statement many conclusions reached by experiment. A possible underlying mechanism is that the changing product fineness leads to changes in the particle crushing strength and in the probability of encounter with the crushing media.

Jan 1, 1969

By Charles F. Park

Mining in the Pacific Coastal Region has passed through three stages of development. First came the gold rush days, a period when gold and silver were the objects of intensive search. Second was the development of the high-grade base-metal deposits and of the smaller and more refractory precious metal deposits. And third was the modern period that covers the discovery and development of the rarer metals, of large low-grade deposits, and of the industrial and nonmetallic minerals. Brief discussions of the salient geologic features of the region and of a few of the better known mineral deposits are given. The regional geology is favorable for continued exploration and discovery of new deposits and districts.

Jan 1, 1968

"The greatest mining center in the state of Utah is the incorporated town of Bingham about twenty-five miles southwest of Salt Lake City. The principal industry of this vicinity, prior to the early fall of 1 863, was lumbering and the first saw-mill in the state was built near the mouth of Bingham Canyon. Early in the fall of that year, George B. Ogilvie discovered gold and shortly afterward the first mining district in the state was organized. Some writers place the discovery of gold in the canyon in the late fifties. If this be so, however, the matter was kept extremely quiet because no mining was engaged in until after Ogilvie's discovery.Bingham was a placer mining camp, producing about one million dollars' worth of dust and nuggets from placers up and down the canyon and in Bear Gulch until early in the seventies, or about ten years after the discovery of gold, when a large body of argentiferous lead ore was discovered and soon after heavy shipments were made from a half dozen or more properties.In 1 8 74, A. H. and George L. Bemis erected the first concentrating plant in the state for the treatment of sulphide lead ores.The history of the camp as a producer of copper begins in the summer of 1 88 7, when Enos A. Wall noticed, in observing prospecting drifts and inclines driven some years before, the discoloration caused by the coppery solution. As a large part of the adjacent ground had been abandoned, he located two claims, which he called the ""Dick Mackintosh"" and the ""Charles Reid,"" after two of his friends.Late in 1896, the Highland Boy Mine produced sulphide ore rich in copper, causing a revival of interest in the copper potentialities of the camp, and during the next seven years a number of new claims were located ."

Jan 1, 1925

Dr. Oldshue has provided a useful summary of a voluminous subject and my task will be to select and direct attention to those areas of mixing theory and practice which are germane to mineral processing in general, and to fine particle treatment in particular. Pulp mixing in impeller actuated reactors occurs in mineral processing in several different applications: (1) emulsification of reagents; (2) mixing pulp with 'reagents as in conditioning for subsequent operations (such as flotation, flocculation or agglomeration) ; (3) high intensity agitation, as in (a) disintegrating and dispersing aggregates, and (b) aggregating particles as in shear flocculation or in selective agglomeration; (4) hydrometallurgy; (5) hydrometallurgy with gas phase (e.g., Arbiter process); . (6) flotation in sub-aeration machines. Attention is invited to 3 above in which two opposite effects can be induced by proper choice of chemical treatment and hydrodynamic conditions. Successful processes for treating mineral fines require excellent aggregate dispersion in order to fully accomplish the liberation stage. Some processes depend further upon selective aggregation following dispersion. The term “dispersion” is often used in different senses which for present purposes will be clarified at the bottom of the next page.

Jan 1, 1979

By George S. Rice

ARIAL maps of prospective mineral-bearing territory have become almost indispensable in all the branches of exploration, and have proved particularly useful in the great oil area of the Southwest. About nine years ago aerial photographic mapping in this area was begun. The early product was lacking in scale accuracy and other control features, which limited its effective use. Since then, the evolution of the technique of such mapping has been steady, with several mapping companies collaborating with five of the leading oil companies, and aerial maps have been prepared covering practically the entire area.Improvements in cameras, film, and developing equipment and practice have resulted in more uniform and clearer photographs, but the outstanding development has been the accuracy obtained with respect to scale and all other control features. Maps are no

Jan 1, 1936

By T. Sterry Hunt

WET processes for the extraction of copper from its ores have of late attracted much attention, especially in Europe, where the use of oupriferous iron-pyrites as a' source of sulphur prevails. These processes present an additional interest, when, as is often the case, the copper-ore's to be treated contain one or both of the precious metals, since the complete separation of these from copper, either in the dry or the moist way, is, as is well known, one of the difficult problems of metallurgy. The principal wet processes hitherto in use for the extraction of copper from its ores, may be included under three classes : I. Those in which the copper in snlphuretted ores is rendered soluble in water by calcining them, after a preliminary roasting which removes the greater part of their sulphur, with a portion of common salt, by which the copper is converted into a chloride (Long-maid and Henderson), or with sulphate of soda, by which sulphate of copper is formed (Monnier). Allied to these is the method by which a portion of the copper is got as soluble sulphate by roasting without addition, a process which is sometimes modified and rendered more complete by re-roasting the lixiviated residues with the addition of a portion of raw sulphuretted ore (Bankart). II. Those methods in which free chlorhydric or sulphuric acid is used to dissolve the copper- from oxidized or roasted ores. These, while simple and efficient, are too costly, except in certain localities where chlorhydric acid is a waste product. Related to them is the plan which consists in exposing the oxidized and moistened ores to the slow action of sulphurous acid mixed with air, by which a soluble sulphate of copper is formed. It has been proposed to decompose the solutions of sulphate or chloride of copper by sulphuretted hydrogen, thus separating the copper as sulphide, and using the liberated acid to dissolve fresh portions of oxidized copper. It is, however, the almost universal practice to throw down the copper from its solutions, however obtained, in the metallic state by the use of iron, either scrap-iron or iron-sponge; although in some instances

Jan 1, 1882

By A. O. HAYES

SYSTEMATIC methods of ore-finding are looked to the more as increasing production requires greater supplies of raw materials. Unrelenting search for new sources of supply is necessary, and all the skill of science must be displayed both in methods of discovering and recovering the minerals necessary to the demands of present-day life. To this end most national governments have some sort of a geo- logical survey and there is a growing understanding of the desirability for cooperation between federal and state or provincial organizations and also financial assistance, from state and private universities, mining companies, railroads and manufacturers. Such surveys are now being directed by well trained geologists selected from federal, state and university departments. Large-scale maps are being prepared and better geo- logical interpretation made, more thorough chemical and physical examinations are being made and original search is fostered, with the result that successful prospecting is better directed, new mining regions are more likely to be discovered, and the life of. old camps lengthened.

Jan 1, 1931

By CHARLES M. A. STINE

IN fighting a war the all-absorbing intent is to win. There is little time to analyze the rush of events or to appraise their consequences beyond the war's end. The united objective is, rightly, success for our arms. Yet under the pressures of a great war there may be compressed scientific, economic and social developments that might have taken many decades to achieve under less urgent conditions. Their effects on our lives and all civilization may be more wide-reaching and lasting than any military conquest. They constitute one of the must imperative incentives to victory. No American, least of all any scientist worthy the name, conceivably could endorse war as a justifiable means to progress. The destruction of life and property wrought by the present war far exceeds the havocs of a century's earthquakes. Most of mankind is burning itself on an altar of paganism. Nonetheless, one fact is inescapable Despite the recurrent malady of war history's overall course is forward. Mankind has the habit of rising phoenix-like from its own ashes to attain greater heights. Progress is immortal.

Jan 1, 1942

By J. W. JESSUH

TO certain people the name of Northern Rhodesia brings only a vague recollection of a distant country somewhere in Africa; to others, it means a big game territory and the opportunity for excellent shooting; to some, a land of sunshine and peace; but to mining men the name signifies the land where the latest discoveries of copper ore are astonishing the mining world and bid fair, in a few years, to make Northern Rhodesia one of the largest copper- producing countries. There is a fascination about this part of the globe that is somewhat similar to southern California, and at the same time there is that feeling of mystery peculiar to a tropical climate. Perhaps it is the isolation, the fear of wild animals, or the influence of an undefinable something which cannot be expressed.

Jan 1, 1931

By AIME AIME

INDUSTRIAL Pittsburgh, the center of the coal and iron and steel industry of the world, was host to the Coal Division at its Fall Meeting held there on Oct. 21 and 22 at the William Penn Hotel. The past year has witnessed remarkable progress in new methods of mining and burning of coal and many of the papers on the program discussed these developments. Nearly 100 had registered at the time of the first session on Wednesday morning and this number increased to 168 on Thursday. Owing to the large number of papers on the program, eighteen in all, it was necessary to hold group meetings on Thursday morning, with a capacity attendance at each meeting. . Chairman McAuliffe was on hand early Wednesday morning to open the meeting. George Otis Smith, representing President Lovejoy, came over from Cleveland where he attended the meetings of the Institute of Metals Division. Secretary Parsons arrived later from Cleveland and spent the whole morning with the executive committee of the Division. Doctor Smith, Secretary Parsons, and J. T. Breunich were the official representatives from Institute headquarters.

Jan 1, 1936

By Dwight H. Seely, Louis R. Records

A process for low-temperature dehydration of natural gas utilizing Joule-Thomson effect in expansion through a throttling orifice has been tested in a full-scale field installation. The results of these tests are presented in the form of performance curves from which the process may be easily evaluated. The effect of separation temperature on condensate recovery from the process is also shown. INTRODUCTION The transportation of natural gas from producing well to the consumer has always encountered the problem of hydrate prevention. This problem has become increasingly important in the past ten years due to the rapid increase in produced gas volumes, production pressures, transportation pressures and distance from producing wells to consumer. Natural gas, as normally produced from gas or gas-condensate wells, is saturated with water vapor at well-head conditions of temuerature and pressure. The solution of the hydrate problem require; but one basic process — dehydration of the gas to a water content which will result in a water dew-point below the minimum temperature to be encountered from the producing well to the point of consumption. Much of the recent development of gas and gas-condensate reserves in the Gulf Coast Area has been in locations which are accessible only by water. High well-head pressures, pipeline construction and maintenance costs and the desirability of final central gas-condensate separation facilities have stimulated the development of dehydration equipment which can be installed at each well and which will permit hydrate-free transportation of both gas and condensate in the same line to central facilities. There are four types of natural gas dehydration processes now used: 1. Adsorptive processes. 2. Absorptive processes. 3. Chemical reaction processes. 4. Refrigeration processes. The first three of these processes are indirect in that they require use of adsorbents, absorbents or reactive chemicals. These materials require regeneration and part of the total gas stream is consumed in the regenerative process. Indirect processes have a wide range of flexibility as defined by allowable operating pressure and temperature, but most are not easily adapted to automatic operation. The refrigeration process described in this paper was designed for installation at the producing well-head. It requires no regenerative cycle and with normal well-head temperatures no external source of heat. The flexibility of this process is limited only by the pressure drop which may be allowed between well-head and transportation line. THEORY There are three basic physical concepts involved in the low temperature dehydration process. These are: 1. Formation of hydrocarbon hydrates. 2. Joule-Thompson effect resulting from the expansion of gaseous mixtures through a throttling orifice. 3. The equilibrium composition characteristics of water vapor and gaseous hydrocarbon mixture.. The chemical composition and physical structure of hydrate; have been described by several investigators.3,4,5,10 Specific conditions of temperature, pressure and composition as well as the requirements for turbulence and presence of free water necessary for hydrate formation have been described by Katz.6 Natural gas hydrates, as they are found in plugged gas pipe lines, have the appearance of packed snow. The mass of these hydrates has low continuous porosity and permeability. Joule-Thomson effect. or the reduction in temperature which occurs when natural gas is throttled throusll a restrictive orifice, is the basic phenomenon which permits efficient use of refrigeration for the purpose of dehydrating natural gas. Joule-Thomson coefficients for gafeous mixture; of methane with ethane and with butane have been reported by Buder.-I~olzer, Sage and Lacey.2 Brown1 predicted temperature drops for pressure drops from enthalpy-entropy calculations. Aside from this work there were no fundamental data found which would be applicable to natural gas mixtures of varying spe-

Jan 1, 1951