Search Documents

By AIME AIME

No democracy such as ours, can ever be prepared for war, because we could never conceivably be the aggressor. The aggressor prepares in secret, designs his new tactics, and invents and makes new equipment and selects the time to strike. If a democracy prepare done year and the war came later, all that it had one would have to bed one over. All that England has today in the way of effective armament has been invented, designed, made, and the crews trained since the war began, because the totalitarian aggressor introduced new types of equipment and new techniques.

Jan 1, 1941

By O. E. Kiessling

THIS announcement of the topics relating to production control, which the Committee hopes to have discussed at the February meeting, supplements the preliminary announcement published in the November number of MINING AND METALLURGY. In the previous article, the writer indicated the kaleide-scopic nature of the questions involved in obtaining better coordination in industry, and that, as a matter of practical expediency, the discussion in February would be limited to the more obvious difficulties in industry which need attention and to those questions which the Committee thinks would be of greatest interest to members of the Institute. But while practical considerations necessitate limiting the program, free discussion of all phases of the subject is urged by 'the Committee. In a preliminary consideration of the production control problem, there loom up two questions which have to be faced: (1) First, there is the question of the extra industrial capacity necessary to meet demand during the ordinary fluctuations of business, commonly characterized as `the "business cycle." Anyone who tries to formulate a program pertaining to productive capacity must decide whether he wishes to discuss the control of business cycles. While this question may eventually lend itself to treatment, the Committee does not feel that it can be considered at present with much profit. (2) The second question arises from the existence of over-stimulated capacity above and beyond peak demands in boom times. Discussion of this topic, it is felt, would be most fruitful. How to prevent capacity from being over-stimulated to an extent beyond any hope of possible demand is a

Jan 1, 1929

By S. Marion Tucker

THE aggregate number of "papers" read within any one year before more or less bored and bewildered audiences is simply appalling. We have seventy to eighty engineering societies alone, not to speak of the many hundreds of societies of every other imaginable kind. And each meets at least once a year to tell what it has found out since the last meeting. All this is very fine and fortunate, at least in the case of the scientific and technological societies; for if even only one significant discovery, one new truth, one new idea comes out at the meeting, the session has been abundantly justified. To many of us, not scientists or technologists, the scientific and technological societies seem to release by far the most useful and important information. What they have to say is often of prime importance directly to human life and to industry, and is perhaps even more important indirectly in its final influence upon social and economic conditions, thus ultimately determining the course of what we like to call civilization. The paper read by that quiet, unpretentious man on the platform ma; mean the revolutionizing of a great existing industry, the creation of an entirely new industry, the gain of millions of dollars to some persons, the loss of millions to others. But, lamentably,

Jan 1, 1940

R. G. BROWN, Bodie, Cal.: Mr. Rickard's paper, with its valuable illustrations, brings into fresh clearness the game of hide-and-seek which the miner must play with his ore-deposit; but, more than this, it goes far towards classifying those perplexing idiosyncrasies which, while unclassified, constitute a labyrinth almost without clue. Probably every engineer can add to the list by the mention of at least one fresh detail from his own experience, and I for one would like to comment on two of Mr. Rickard's divisions. To what he has written about " walls within walls" and " walls without walls," the accompanying Figs. 1 and 2 may be appropriate, the more so as they represent conditions obtaining in a part of the Butte copper-belt more typical of the copper-veins as a whole than the Gagnon, which, in some respects the most interesting mine in the camp, stands almost alone in many particulars. (See nuns., xvi., 62.) Fig. 1 was sketched in January, 1895, in the stopes above the 700-foot level of the Colusa-Parrot mine, east of the Parrot and southwest. of the Anaconda. The stope, the commercial foot-wall of which is shown at A, was 30 feet wide at this section, the pay-ore being massive chalcocite, jumbled with bornite, pyrite, quartz and thoroughly broken-down granite. A and At are inch-thick seams of black talc; B, B' and B" are also talc, possibly 1/8-inch thick. In the plane of the section the "banded quartz " and " quartz and pyrite " were both of too low grade for extraction, but 5 feet back along the stope had been of fair value. The granite with quartz and bornite between Bt and A' was pay-ore, but that to the right of B" was not. In both cases the ferro-magnesian minerals had been removed, leaving, where not obscured by ore, faint, dark patches. Between A'

Jan 1, 1897

By Clint L. Milliken

The smelter is often considered the flywheel of the copper industry. No other unit can produce such a uniform product from so many starting materials. Direct-smelting ore, concentrate, precipitate, refinery slag, and scrap in almost any combination can be processed into blister or anode copper. Copper smelting practice has advanced little in the last century. It is still basically matte smelting, although the source of matte has changed from the blast furnace to the reverberatory furnace because of changes in smelter feed, and the Great Falls converter has been replaced by the Peirce-Smith converter. This lack of progress has continued because the economic forces required to produce change have not been of sufficient magnitude. Traditionally, the smelting, operation has required only about 10% of the total cost of producing copper from its ores and this minor cost item has not warranted change until recently.

Jan 1, 1971

Jan 1, 1924

By George T. Hansen

WHY try to find oil in Utah? Why try to find oil anywhere? Isn't there too much oil already? Answers to these questions involve general oil conditions but are pertinent to my subject. In the first place oil produced in Utah up to the total amount of local consumption would not be subject to nor concerned with the national oil situation. An oil field in this State capable of producing up to 15,000 bbl. per day would have a large value and prompt realization. In the sec¬ond place, there is not too much oil nationally although the markets have been upset temporarily from time to time. Petroleum is so necessary and is in such general demand that an oil field anywhere, anytime, is a valuable and live asset. The oil business in general shows the best condition of any major industry. It has never been hit as hard as most industries and 1932 was a large improvement over its low spot of 1931. It can be and probably will be the one to lead the country back into business stability. Consumption of its products has been reduced less than that of any other important commodity. There are good and valid reasons why it should have been making a normal profit continuously. It has the oil and the processes and the facilities and the policies and the consumption of its products. There is only one reason why it has not been profitable recently and that is the lack of intelligence of from five to ten per cent of the producers. An op¬erator lacks intelligence when he cannot see that it is better for him to sell one barrel of oil at $1 than two or three barrels at 25 or 35c. per bbl.

Jan 1, 1933

By John W. Padan, John E. Crawford

Beginning with a small but positive participation in undersea mining, the Bureau of Mines continues its active investigations into this potentially tremendous field. The Bureau began its active role in undersea mining in September 1963, with a small task force of three dedicated scientists and a secretary, establishing headquarters at the old Tiburon Naval Net Depot about seven miles up the coast from San Francisco. The past months have been both busy and productive. With 22 Federal agencies involved in oceanography, it logically was the intent of Congress that the Bureau of Mines undertake research concerned only with the technology of marine mineral production and utilization. The Bureau has maintained this purpose in its activities at Tiburon, for while institutes, universities, the Navy and other Government agencies have developed exceptional programs in the fundamental science of the oceans, commonly called oceanographic research, little has been done toward advancing man's ability to exploit the ocean floors other than by drilling for oil and gas and sulfur.

Jan 3, 1965

Charles Catlett, Staunton, Virginia (communication to the Secretary*): I have had occasion to examine a few of the irondeposits in the immediate section of which Mr. Watson speaks, but have not had an opportunity to visit any of the well-known manganese-deposits. I find the former can be very safely read in light of the information which it is possible to get from the same measnres farther. north, where they are less completely decomposed. In the same way all of his conclusions in regard to the geology of the manganese-deposits bear out their occurrence in Virginia, when we allow for the far more complete decomposition in the section he has so carefully studied. Judging from the same measures farther north, I think he will be safe in agreeing even further with Penrose as to the origin of these ores. Some years ago I carried on prospecting work in these measures in Virginia, in which the iron-ore and manganese-ore were followed down to undecomposed material, and in which their occurrence along a definite line of stratification, and apparently a part of the original bedding, was plainly shown. This is unusual, however, even in the section of which I speak. At Crimora, Virginia, the decomposition is quite complete; at the same time the results of some hydraulic work, which has been done there, disclosed, at the time of my last visit, the manganese interbedded in the residual clay along a definite and distinct plane parallel to the bedding of the underlying quartzite, and which, as is shown at other points, corresponds with the plane of the original material. In view of the phosphorus reported by Mr. Watson as existing in the Cartersville ores, and the not uncommonly prohibitive amount in southern ores, I am interested to know whether

Jan 1, 1904

By James Hyslop

MECHANIZATION of American coal mining continues to make rapid progress. Economic pressure will compel abandonment of manual methods wherever possible and will also provide the incentive needed for the improvement of machines and mining systems. However, rapid progress may be made along strictly technological lines and at the same time much slower progress in approaching maximum productivly and efficiency. One can well ask, just how efficient are mechanized mines, and to what extent is productivity affected by the mental attitude of management and workers?

Jan 1, 1946

By A. B. Young

THERE were produced in this country in 1923 probably in the neighborhood of 12,000 or 13,000 tons of refined and crude arsenic, by far the greater portion coming as a by product of smelting operations. Early this year copper smelters were producing arsenic at the rate of about 425 tons per month and lead smelters at the rate of 7;0 tons per month. During the entire eighteen years prior to 1919, there were produced in the United States only 47,000 tons of arsenic, which amounts to only 25 per cent. of the present output. The great increased demand has come about through the augmented use of arsenates as insecticides and arsenates as weed killers. In an extract from "Mineral Resources of the United States" on "Arsenic in 1922," Messrs. Heikes and Loughlin say, "The minimum possible demand for arsenic in 1923 was estimated at the end of 1922 to be about 13,000 tons, including 2000 tons for plate glass manufacturers, 3000 tons for lead arsenate, 3500 tons for calcium arsenate, 1500 tons for weed killers, 1200 tons for Paris green, 1000 tons for sheep dips and 750 tons for proprietary mixtures. More recent information, however, indicates twice as great a demand for calcium arsenate." The latter has found great use in the last three or four years as a weapon to combat the boll weevil pest of the southern cotton belt. ~t the present writing refined white arsenic is being quoted on the New York market at from 13)d c. to 1455 c. per Ib., while the average price during the eighteen-year period just mentioned was 4.8 c.

Jan 1, 1924

By E. DeGolyer

WAR has wrought sharp and sudden changes in the pattern of the oil industry. The most obvious and most striking of such changes have been in the fields of transportation and refining. A third of the world's total oil production formerly started to market, tanker-borne, over the waters of the Gulf and Caribbean. Most of this oil went to our North Atlantic ports, supply points for the world's greatest consuming center. This tremendous traffic, disrupted by the loss of tankers as a result of requisition for military purposes and by the activity of enemy submarines, has had to be substituted largely by such lines of supply as could be improvised without loss of too much time. No single solution for this gigantic problem has been found nor is it likely to be entirely solved for some time to come. It has been solved in part, however, by rearrangement, reversals, and patching up of existing pipe-line systems; by overland transport of crude and products in tank cars on a scale never before attempted; by barging over inland waterways; and through the construction at long last of the "big-inch" line, the first leg of which is just being put into operation as far as Norris City, III. The tank-car traffic alone, reaching a peak of deliveries of 856,710 barrels per day into District 1 during the week ending Sept. 19, 1942, and accomplished at an expense of millions of dollars in extraordinary transportation costs, defrayed by the Defense Supply Corp. and by the mobilization of tank cars from all over the nation, is a story worth the telling but by some of those who directed it.

Jan 1, 1943

By Albert L. Toenges

Alaska requires an adequate fuel supply for its development, and has large potential coal reserves ranging from lignite to subbituminous and anthracite. Coal production in the Territory now is less than the requirements. In 1947, production was 361,000 tons, divided about equally between bituminous coal from the Matanuska field and subbituminous coal from the Nenana field. There is need for development of modern mechanized mines, which should produce the required output with a minimum of workers. These mines should not be thought of in the light of large potential capacity, as in the States. However, these new mines should be developed by modern methods, which should result in lower costs than at present. Because of the diverse physical conditions in the coal fields, intensive investigation by diamond drilling is necessary to properly plan the development and equipment of mine sites at minimum cost. The Bureau of Mines is doing this now in the Wishbone Hill area of the Matanuska field. All coal land in Alaska is government-owned and subject to the Coal Leasing Act.

Jan 1, 1949

By K. C. Sclater

GAS as a factor in the efficiency of oil production, might be a better title for this paper as it deals in general with the significance of the gas-oil ratio as an index of the efficiency of oil production and briefly discusses oil production methods with reference to the gas-oil ratio in wells, particularly during the early life of a field. In the recent hearings held at Washington before the Federal Oil Conservation Board the fuller utilization of the energy contained in the gas occluded in or associated with the oil underground was stressed by some of the speakers when referring to greater ultimate recovery of oil. One speaker commenting on this point said in part, "There is ample evidence indicative that if the gas associated with the petroleum in our fields were conserved and elevated gas pressure maintained in the oil sands during their productive life, the ultimate production of oil could be greatly increased."

Jan 1, 1926

By Lysle E. Shaffer

TEACHING engineering students how to write and speak effectively -is one of the greatest problems facing the technical schools today. No phase of engineering education has received more criticism, and rightly so, for the criticism is justified. Year after year we continue to graduate men that are indifferent to the use of a tool they will need every day of their lives. Our young engineers cannot write a clear, concise report, and their business letters are a disgrace to the profession that takes pride in precision. The problem is not new. The remark ascribed to Sir James Barrie, that "The man of science appears to be the only man who has something to say, just now-and the only man who does not know how to say it" is as uncomfortably true today as it was thirty years ago. The records of meetings of engineering educators and the transactions of the engineering societies show that the inability of the engineer to communicate his ideas has been discussed for years. Engineering educators, prodded by industry, have recognized that the problem exists, but they have not solved it. Instead they continue to expose the student to composition and rhetoric, hustle him through English and American literature, and then blame his high school because he does not know enough English grammar to write a clear sentence. We must face the fact that the graduate is not going to reflect on the high school, but on his college. If the high school has shirked the job, the responsibility for correction rests on the faculty of the professional school.

Jan 1, 1948

By Benj. Lazer

Multiple seam mining has been studied and writ- ten about extensively in the past and in the latest review of the subject in 1956 David Stemple covered it exhaustively. The present discussion has to do with only one phase of the problem-"The effects on upper seams when the lower seams have been mined first." The study presented here is based on observations made in mining operations in southern West Virginia and adjoining areas of Virginia and Kentucky during the past 43 years. These observations are largely confined to the Pocahontas coalfields of southern West Virginia which have, since 1883, produced well over one billion tons of coal from an area of about 300 sq miles and where multiple seam mining has been active, or is now active, at more than 40 operations. The observations and conclusions as to the effects on upper seams when lower seams have previously been mined are therefore related only to the local coalfields in the area of the three states named but I believe that they can be applied generally to other coalfields.

Jan 9, 1965

By Noel Cunningham

MANY excellent descriptions of the mills of the, Porcupine district have been written, but no discussion exclusively devoted to the metallurgical technology has been given. These notes are intended to cover this feature briefly. They are based upon 2 ½ years' mill operation in the district-i.e., practically since the beginning of metallurgical operations. Character of the Porcupine Ore.-There is no oxidized ore in the district, the surface having been deeply planed by glacial action in recent geologic time. The precious-metal content is about in the proportion of 85 of gold to 15? of silver by weight; hence, the silver is practically negligible. There are two classes of Porcupine ore, having very different characteristics; these will be referred to throughout this paper as Class A and Class B. Class A ore is a pure quartz with inclusions of schist. Generally it is heavily fractured .and breaks down readily to sharp, hard grains, about minus 10 plus 20 mesh, requiring further comminution to release the gold. It carries very little pyrite; the gold is entirely free and apt to be coarse, but often spongy, going into solution readily on that account. This gold is 60 per cent. to 85 per cent. free milling, depending on the grade of ore. Class B ore is an iron silicate schist, strongly laminated, carrying 4 to 5 per cent. pyrite; its specific gravity is 2.8 to 3.0, depending upon the amount of mineralization. In breaking the ore in the mine, generally over 25 per cent. of material through a ½ -in. ring is made; the ore readily breaks down in milling and makes a comparatively large amount of non-crystalline slime; owing to its high specific gravity, however, it is quick settling.' In my opinion, the gold in this ore is free, but so finely divided that it will neither pan nor amalgamate; it appears to be disseminated through the rock and not chiefly associated with the pyrite. Veins of Class A ore occur with or without side walls of Class B, and veins of Class B occur unassociated with Class A; more often the veins are closely banded, Class A and Class B alternating, generally with Class B in excess. Both classes of ore are more-or less blocky at times, and with ref¬erence to Class B this is indicative or low gold content.

Jan 3, 1915

By Samuel Hoyt

THE hardness of annealed copper has been given in the literature and is easily obtained by any of the standard methods of hardness testing. It is not our intention to correct published values or to add to them, but to describe tests of two bars of annealed electrolytic copper in which the methods of Meyer's analysis were employed. MEYER'S ANALYSIS OF BALL INDENTATION TEST The ball indentation test is probably the most valuable hardness test we now have but, as it is carried out in the Brinell or Rockwell test, the result may be seriously in error without the operator suspecting such to be the case. This condition results from the isolated and uncontrolled nature of the measurement. The accuracy depends on the accuracy of the equipment and the care and skill used in the operations; there is nothing in the impression diameter, which is all that is measured, to indicate the presence of error. Meyer's analysis supplies a control of the measurements that goes far toward eliminating unsuspected errors. The principles of this work maybe obtained from elsewhere.1 As this subject has not received the attention of this Institute, it may be well to summarize the more important points as follows.

Jan 2, 1926

By Nathaniel Arbiter, Edward L. Vickers

Complete automation of concentrator operations through computer control has been under increasing consideration by American engineers for several years. Although justification for full-scale automation of a mill must ultimately be economic- added profits exceeding instrumentation and development costs-the technical feasibility of automation will be determined by the availability of requisite, detailed knowledge of the various unit operations in the plant. This poses problems. BASIC PROBLEMS WHICH MUST BE CONSIDERED A hypothetical porphyry copper mill will be used here to illustrate these problems. Its flowsheet will involve: mining, crushing, storage, grinding and classification, flotation, product de-watering, and disposal.

Jan 8, 1962

By Dave H. Barnett, Brij M. Moudgil

The flotation technique as employed by Florida phosphate producing companies for the beneficiation of fine phosphate particles has been standardized over the years. Lower recoveries of coarse phosphate rock by froth flotation technique, however, led to the development of new methods based on skin flotation of phosphate agglomerates. Recent developments of floating coarse rock in large flotation machines have not yet convinced the rock producers of their higher separation efficiency. It is interesting to note that the selection of a particular machine is still based on equipment preference by an individual company as well as proven performance of a particular machine for upgrading a specific material. Various techniques which have been developed to beneficiate the coarse phosphate rock have been discussed. Performance of the individual techniques is presented.

Jan 1, 1980