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By W. Armstrong Price

INVESTIGATION by German chemists during the World War showed that particles of iron oxide form rapidly in iron pipes carrying hydrogen gas under pressure when the gas contains small amounts of water. Under these conditions, the gas frequently exploded when expanding into a dirigible. The explanation of the explosions lies in the building up of a charge of static electricity in the flow just beyond the orifice and the ignition of the gas by a spark accompanying discharge of the electricity. Friction between the moving particles and the pipe generated the electric charge, which was manifested by a pale blue glow formed in the flow at pressures above two atmospheres. In one experiment, this glow, at eighty atmospheres, extended for a distance of forty to fifty centimetres, but did not ignite hydrogen and air mixtures until the charge was col-lected by a conductor and discharged across a gap between electrodes placed at the side of the column of gas. Autoignition did not occur when this discharge was effected at a distance from the gas column, nor if the gas used was thoroughly dried and free from impurities. The electric charge has been studied by placing various wire and screen conductors in the outcoming stream of gas, Guest having summarized these experiments. The application of these conclusions to fires in petroleum and natural gas issuing uncontrolled from wells is made in the following paper, citing the ignition of a wild gas well in Texas.

Jan 1, 1936

By P. H. Dudley

A Discussion of the Paper of Prof. Howe. (Bi-Monthly Bulletin, No. 14, March, 1907, pp. 169 to 274.) P. H. DUDLEY, New York, N. Y. (communication to the Secretary*) :-The characteristics of Prof. Howe's metallurgical papers are, that he is able, from the mass of confusing evidence on the subject, to make an analysis and present hypothetical and essential principles in concrete form for consideration and discussion. I can appreciate, from the practical side of the subject, the arduous labor of collecting and investigating the data that is essential to prepare the paper. Much of the data necessarily came from material of preceding years. of manufacture in which there was allowed time for chemical reactions of the recarburizer, and for the elimination of the oxidation-products before teeming the ingots. This condition gave a favorable tinge-element to free the metal from slag- and other impurities, but, in allowing the. ingot to cool before charging in the furnace, the time-element entered as a detrimental factor in the development of the pipe or shrinkage-cavities, which gave an ingot-structure deficient in soundness. The interpretations from such material must be made with due allowances for the methods of manufacture, and must be given proper weight, as general facts, in subsequent arguments. The difficulties under which investigators labor are not easily surmounted in differentiating between reliable and unreliable data incident to variables of methods of manufacture, chemical composition of the alloys of steel, mediocre practice and that of the highest state of the art. Modern practice and large outputs in Bessemer steel have reversed the effects of the time-element-by cutting short the chemical reactions of the recarburizer and the elimination of

Jan 5, 1908

By HARRINCTON EMERSON

UNEMPLOYMENT is the most ominous shadow ahead of the industrial nations today. Only two great industrial countries are free from unemployment, France and the Soviet Commonwealth. In France the social unit is the family, not the individual. This has saved France. In the Soviet Commonwealth, development is proceeding so rapidly from agricultural to industrial that there is still a dearth of muscle workers in the non-agricultural enterprises. In the other industrial countries unemployment results both from acute temporary recession in industrial activities and from the rapidly increasing substitution of the machine for the man. Temporary recessions can be mitigated, alleviated by makeshifts, often ill considered. Secular recessions due to a fundamental change in the way of accomplishing physical, chemical results cannot be cured by any makeshift. There must be a period of transition. There is therefore before us the three- fold problem, immediate, prosimate and ultimate.

Jan 1, 1930

By T. A. Rickard

Slovenliness is as reprehensible in words as in clothes. Much writing that we recognize as poor in style is merely sloppy. Just as some students postpone the necessary shave or forget to change their collars, so young engineers in writing drop their articles, definite and indefinite, or omit prepositions where they are required, possibly to compensate for these they use unnecessarily The work will begin [on] Saturday. The work will begin [on] Saturday. `Influenza seriously affected many mines [during] the last three months. Flotation in America [during] the last two years has made tremendous strides. Construction of the mill started [on] August 12, 1915, at which time 75% of the excavation was completed. The idea I wish to convey is [that] there are mineral deposits to which the present law applies badly. For this reason, if there was [for] no other, the ownership of the ore below and [of] the surface above should go together. When a unit of mapping is furnished, be the unit a claim or [a] group of claims, it is necessary .. . A fully stocked store was started in Park City and all employees [were] sold merchandise on a strictly cost basis. The word "merchandise" is left without government or agreement. I suggest: ". . . and merchandise] was sold to all the employees on a strictly cash basis.". The verb `be' is serving concurrently both as a principal and as an auxiliary in the following: At first the work was interesting and [was] liked by most of the men. The sulphide ore was more complex or [was] milled at an increased cost. The failure to repeat tie auxiliary verb in successive clauses is a common error, as in The filter is filled with liquid allowed to empty, and then ignited.

Jan 1, 1931

By Charles D. Walcott

Jan 1, 1901

By C. M. Loeb, A. M. Gaudin, J. H. Brown

THE object of most size reduction operations in the mineral industry is to liberate the grains of valuable minerals in the ore from those of the gangue. This is usually accomplished by crushing and grinding the entire mass of ore until there is only a small probability that any single particle contains more than one mineral. During this size reduction only limited control exists over size or composition of the particles exposed to the breaking action, and there is no control over the paths followed by cracks generated during the operation. This lack of control usually results in overgrinding and in production of large quantities of very fine material. The first detriment, overgrinding, is costly in itself, but when combined with the second factor it is doubly so. Not only is the fracture of a free particle unnecessary-the fracture of these particles may also make subsequent separation operations difficult, inefficient, and wasteful. It has been pointed out' that if the object of size reduction is to liberate the valuable mineral component of the ore then, ideally, fracture should follow intergranular paths to the exclusion of trans- granular ones. This would result in liberation of the valuable minerals with as little size reduction as possible. This ideal comminution operation is referred to as intergranular comminution, and it was the object of the investigation to determine the extent to which it could be developed by heat treatments.

Jan 4, 1958

By AIME AIME

PRACTICALLY all the Section delegates as well as a sprinkling of Institute officers and mere members were on hand for the annual business meeting of the Institute on Monday afternoon of the Annual Meeting. President McAuliffe presided, with C. H. Mathewson as associate chairman. Americo Albala was first called on to discuss the work of the Pan American Institute of Mining Engineering and Geology. C. Will Wright said that the need for such an organization was evident, and a resolution was passed asking the incoming President to appoint a committee to investigate cooperation with that body, of which Mr. Albala is executive secretary.

Jan 1, 1943

By Ferid Kromer

This paper is the first in a series which will describe geology, mining methods, and production costs of some, of Turkey's more important minerals. In this paper the economically significant minerals-chromite, meerschaum, and magnesite-of the Tagtepe district are described. The cost data presented are believed by the author to be the first made public on Turkish chromite mining.

Jan 1, 1950

By W. R. Barclay

IN MY general contact with industry I have become more and more impressed with the need for the closest possible co-operation between engineers and metallurgists, and particularly with the need for appreciation of the work that each group is doing to assist the other. Also, I am convinced that from time to time it. is vitally important to a true perspective of human progress in all its branches, and certainly a salutary corrective of undue optimism and pessimism to endeavor to carry the mind hack over certain periods in the advance of technical knowledge, and form some kind of broad estimate of what has been accomplished in the application of science to industry in the fields with which we, as individuals or groups, may for the time being be concerned. We cannot without some appreciable mental effort realize what our forerunners have dine For us. If the young engineer or metallurgist entering industry today could be suddenly transported to a quarter of a century ago, and be compelled to work with the materials then available and within the limitations of knowledge then attained, he would, on his return to present-day life, have a much greater appreciation of what has been accomplished before lie arrived on the scene, and, what is even more important, a far more acute sense of its inherent value to his profession. I propose here merely to indulge in a general summary of the subject of improved engineering metals and alloys rather than in details, and to deal exclusively with developments within my own experience.

Jan 1, 1938

By B. R. Coil, C. A. Ross

NEW demands for underground power in the Miami mine of the Miami Copper Co., Miami, Ariz. has brought about expansion of the distribution system for both ac and dc power. Progress in mining equipment and the normal changes in the mine were responsible for this increased demand. Early power requirements were for pumping and haulage. A 440 v ac power line down No. 5 shaft took care of a small pumping load and shaft station lighting, 275 v dc power was generated by motor generator sets on the surface, with a churn drill hole from surface to the 570 haulage level serving as a cableway. Electric lights were installed where power was available, and thus were confined to the haulage level and shaft stations. All industrial power in the Miami area is 25-cycle, which dates back to the hydroelectric generator installation at Roosevelt Dam in 1908-10. The Problem The main haulage level was moved to the 720 level and later, to the 1000 level, requiring a longer feeder line with the resultant voltage drop. Also, as mining progressed to the east, the churn drill hole for the power cable would have been subjected to subsidence cracks. The first extension in the use of electricity was in electric blasting. About 1935 the mine went to electric blasting, using the dc haulage current. Bringing electric current to the working levels of the mine for blasting greatly expanded the use of electric lights. Lights were used in tool rooms, powder and cap magazines, stairways, and other semi-permanent installations. Like all mines, Miami Copper began to study and experiment with mechanical mucking and transportation of ore by slushers, shakers, and belts during the late 1930's and early 1940's. At the beginning of the program, power was supplied from the haulage level 275 v dc system. Later it became necessary to run a cable, carrying 440 v ac power, down the No. 7 ventilation shaft. The increased use of power came about gradually, and many new problems were added, not the least being the introduction of switch boards and power cables into the working areas of the mine, where drifts and crosscuts take weight, and require repairs. The 25-cycle current presented special problems, in that 25-cycle transformers are twice as large and about 2V2 times as heavy as 60-cycle transformers of the same power output. The 25-cycle transformers were considered too large for installation in the mining areas. In 1947 the distribution system was revised and standards were adopted, governed by the following

Jan 1, 1952

By P. W. Bridgman

DURING the war, the Navy undertook the construction, under my direction, of an experimental gun embodying features designed to lessen the cost and time of production. These experiments were initiated after representations as to their, desirability had been offered by myself, by the Naval Consulting Board, and by the National Research Council. The first drawings were made in June, 1917, and the experiment was completed in November, 1918. For the sake of clearness it will pay to recapitulate briefly the fundamental idea of gun construction. It is well known that if a hollow cylinder is subjected to internal fluid pressure, the maximum stress occurs in the inside layers, the outer parts carrying much less than their due share of the stress. This inequality of stress is more pronounced the thicker the walls of the cylinder. If such a cylinder is pushed to the elastic limit, failure in elasticity will take place long before the outer layers have reached the limit of their capacity. Economical use of the material would demand, however, that all parts of the cylinder reach the limits of their capacity simultaneously. This may be brought about, at least in cylinders of not too great thickness, by producing in. the inner layers an initial compression, and in the outer layers an initial tension. The effect of internal pressure is at, first to relieve the compression of the inside layers, while increasing the tension of the outside layers. If the initial stresses are properly distributed, all parts of the cylinder will reach their elastic limits simultaneously, thus giving a cylinder of maximum strength for its weight. In gun construction as hitherto practiced, this initial distribution of stress is produced either by winding the inner tube with wire, a common English practice, or by shrinking hoops over the inner tube, which has been the standard American practice. Either process is long and expensive, particularly with the larger guns, 12- or 14-in., which require

Jan 2, 1920

By Charles Will Wright

THOSE that attended the seventeenth International Geological Congress held in Russia last summer had an excellent opportunity to gather data and to form impressions on the progress made in the industrialization of the country, particularly with regard to the mineral industries. Several trips to places of interest were arranged, supplementary to the technical sessions held in Moscow, the one to the Ural region being that which I selected as being most likely to be of interest. The accomplishments of the last decade in opening up new mines and building new metallurgical plants in the Soviet Union have been outstanding. This could only be accomplished by a central government ready to employ the best technical talent, which was

Jan 1, 1937

By E. M. Wise

WHEN man became dissatisfied with the mere utilization of physical force and began to use weapons, he made a definite stride forward. At first he used sticks, animal bones and stones, often rudely shaped to some particularly lethal form. These devices, while crude, were moderately effective. How- ever, some of the brighter men of the tribe found that certain particularly heavy "stones" were somewhat ductile and could be hammered into more effective weapons than those previously known. Later, probably through the misuse of one of these weapons to stir the campfire, it was found that heating softened and perhaps actually melted the material. The process of annealing had been discovered! Smelting the more easily reducible metals was in all probability one of those fortuitous accidents which was followed up by thoughtful researchers who ultimately developed the technique of mixing various ores to produce bronze and even some of the nickel content alloys. The resulting products were at first lumps of more or less ductile material which could be hammered to shape, and were thus incidentally hardened by this process. The hardening of metals by alloying and cold working remained for many centuries the only known methods for improving their properties.

Jan 1, 1931

By D. R. Cook, W. M. Shepard, H. T. Morris

The East Tintic district in central Utah has produced ores of gold, silver, copper, lead, and zinc valued at more than $120,000,000. All of this ore has been produced from blind ore bodies in Paleozoic sedimentary rocks that are concealed beneath hydrothermally altered volcanic rocks and cut by intrusive bodies of Eocene age. The Paleozoic rocks, which range in age from Early Cambrian to Mississippian form the core and limbs of a large, northtrending asymmetric anticline that is cut by low-angle thrust faults, high-angle transcurrent faults, mineralized fissures and faults, and normal faults that are both older and younger than the mineralized fissures. The ore bodies generally may be grouped into two classes: ( 1) massive replacement bodies that are rich in silver, lead, zinc and manganese and (2) fissure veins that are valuable primarily for their content of gold, copper, and silver. The replacement ore bodies are localized chiefly in the Middle Limestone Member of the Ophir Formation of Middle Cambrian age where it has been thrust-faulted against older or younger rocks and cut by northeast-trending mineralized fissure zones. The fissure veins primarily are productive only in the Lower Cambrian Tintic Quartzite. Extensive lowgrade deposits of lead-zinc-silver ore recently have been discovered in Devonian carbonate rocks in the Lower plate of the East Tintic thrust fault but as yet are unevaluated. The principal guides to ore include: ( 1) intersections of northeast-trending fissures and crossbreaking faults that brecciate the carbonate rocks; (2) zones of late-stage pyritic, calcitic, and sericitic alteration in the lavas; ( 3) primary geochemical anomalies in the altered rocks; and ( 4) mineral zoning patterns of the known ore bodies. The present development of the Burgin mine would seem to assure the continued productivity of the district for at least a decade.

Jan 1, 1968

By C. Chamberlain

The Telfer Project, Australia's newest, largest, and most remote gold mine treats 480 kt of ore grading 9.33 g/t derived from open pit mining operations. Coarse gold is recovered by gravity concentration with jigs and further upgraded wing a continuous strake launder table, and by amalgamation. Remaining gold is recovered in a cyanide circuit and incorporates flat bottom air agitators, counter current decantation (CCD) and stellar filters for clarification and precipitate removal. Overall recovery into a bullion averages 98%. The mill incorporates a number of design features that allow for maximum efficiency and security wing a minimum number of operation personnel.

Jan 1, 1983

By L. F. Pett

ALTHOUGH Kennecott's orebody has long been outlined, it is still necessary to define further its limits. This mine, long an advocate of churn drill methods, recently supplemented its practice by using a diamond drill. So far, the diamond drill holes have been along the main canyon floor which traverses the mine area. This zone, highly fractured, is cut by numerous friable quartz veinlets encountered within the porphyry. These veinlets, formed by filling contracted porphyry fractures with hot, siliceous, mineral-bearing solutions, are often more highly mineralized than adjacent porphyry. They pulverize on contact, yielding only slight amounts of core. For this reason neither analysis of core recovered (amounting to 37.5 pct of approximately 10,000 ft of hole drilled) nor sludge analysis considered separately would give correct assays. The following equation has been adopted: actual weight theoretical actual weight core — theoretical weight sludge Drilling is done un.der contract. Collection of core and sludge samples together with double-checked assaying is done by the company. Microscopic, specto-graphic, and X-ray examination of rock specimen saved is carried on at the University of Utah. A fund, set up by Kennecott Copper Corp. at the University, has encouraged cooperation in solution of mining research problems. The drill used is a Longyear hydraulic powered by a Waukesha 26-hp gasoline motor. A pump, Bean Royal type, is powered by a 7-hp Briggs-Stratton gasoline motor. Weight of unit is 4000 lb and is placed under tripod of 35-ft wood poles within a 25-ft sq area. The following results have been attained: Avg depth of hole drilled, ft 1215 Avg drilling depth per 8-hr shift, ft 10.11 Core Size, In. Avg depth of NC casing, ft 21 2 11/16 Avg depth of NX casing and size core, ft 178 2Ye Avg depth of BX casing and size core. ft 427 1% Avg depth of AX casing and size core, ft 585 1 5/32 Through the use of metal sludge collection boxes, 12 ft long, 18 in. wide, and varying from 12 to 24 in. in depth, sludge recovery has been maintained above 95 pct. Samples, both core and sludge, are assembled for each sample interval and averaged in 50-ft bench increments. Determinations for mineral values are made at both the mine and mill. Assay results varying in excess of 0.05 of copper assay values are rerun to determine correct assay. The organization chart for the Kennecott Utah copper mine is shown in Fig. 1. The Utah mine requires approximately four men per shovel shift to drill solid rock, properly slope banks, and trim loose material from the top of bench sections in making them safe for men and equipment working below. During recent years, while the mine has been worked day and night, powder crews have worked day shift only. Series of toe holes drilled back of advancing electric shovels comprise approximately 70 pct of all mine drilling. These holes, spaced about 21 ft apart, have a depth of 24 ft. Of the footage drilled, 25 pct is for vertical holes either 24 or 28 ft deep, spaced about 28 ft centers along the top rim of banks. This combination of toe holes, using an Ingersol-Rand DA 35 drifter mounted on a tripod and the vertical holes using an Ingersol-Rand Type X71 wagon drill is standard practice above the pit elevation. These benches are 68 ft high, with a few exceptions, while benches below the pit elevation are 50 ft high and require very little drilling other than toe holes. Five benches, varying in height from 80 to 100 ft, require a combination of toe holes plus vertical holes and bank holes or electric churn drill holes. Bank holes using the DA 35 drifter and electric churn drill using Bucyrus-Erie Model 29T, account for 5 pct of feet drilled. Until the past year, drilling of fill material on upper levels was accomplished by churn drill method. Wagon drills are now used for fills because they can be set up and drill a hole an hour. It is necessary to run an air drill 7 hr for each 8-hr shovel shift. Average drilling rates during the past year were as follows: DA 35 drifter using 2 and 3-man crews — 4.36 ft per man hr X 71 wagon drill using 2-man crews — 6.45 ft per man hr DA 35 drifter bank holes, 3-man crews — 2.53 ft per man hr Bucyrus-Erie churn drill, 2-man crews —1.9 ft per man hr Total mine avg — 4.57 ft per man hr Mine practice assigns powdermen to job locations where they perform all drilling and blasting work within the area. Almost as much labor is consumed in springing and loading holes as in drilling them. Average powder consumption is approximately as follows: Per Electric Shovel Shift, Lb To spring and chamber holes — 50 Blasting — 500 Trim banks — 50 One fifth of all powder used is Hercules hercomite bag powder while four fifths is Hercules gelamite 65 pct strength in 1 Vi in. x 8 in. sticks. Frozen material, overhanging from top banks, creates a winter hazard to shovel operators and equipment. Experiments are being conducted with a high-speed Hercules powder in an effort to eliminate this condition. Banks are trimmed by powdermen who lodge 8 or 10 bundles of powder, containing 15 or 20 sticks each, across the upper surfaces of each working face. To each bundle of powder is attached a primer with 6-ft fuse which is lighted as the powdermen, who have lowered themselves down the bank on ropes, ascend to safety. Three angle dozers, D8 caterpillars, make grades and move supplies for the average 31 drilling machines working daily. Compressed air is furnished by three Ingersol-Rand compressors, each with rated capacity of 3750 cu ft of air per min at 100 lb reservoir pressure.

Jan 1, 1952

By HAROLD VINTON COES

MANAGEMENT has been tersely defined as getting things done through the efforts of other people; but before we proceed further, let us distinguish between administration, management, and organization. Oliver Sheldon in his book, "The Philosophy of Management," offers the following definitions: Administration is the function in industry concerned in the determination of the corporate policy, the co-ordination of finance, production, and distribution, the settlement of the compass of the organization, and the ultimate control of the executive.

Jan 1, 1943

By Thomas T. Read

I. INTRODUCTION. WHEN so much has been written upon a subject on which so little definite information is available as upon this, some reason must needs be assigned for adding to the volume of literature. A sufficient reason is found in the probable great future importance of China as a producer of mineral wealth. The present undeveloped state of mining in the Empire is due to many causes, among which the most important are the relatively simple needs of the population, the lack of transportation-facilities, the inelastic regulations governing the industry, and the superstitious reluctance of the people to make excavations which might disturb the spirits of the earth and air, or of ancestors. Iron is the metal most in demand, yet the needs of the population, until recently, only made necessary a production of approximately 0.5 lb. of iron per capita per year. The present annual production of iron for domestic consumption, in the United States, is nearly 600 lb. per capita. The curious state of development of transportation in this interesting country has been a greater handicap upon the mining industry than upon any other. The point upon which it hinges is the absence of a road-system. Except for a few military roads, now almost impassable, there are no roads in China; that is to say, there is no land which is set aside as a right of way, belonging to the commonwealth. Throughout the agricultural districts, generally speaking, the entire area is in private ownership, and the lines of travel are between fields. There is a constant struggle for existence between the owners of the land and the traveling public, with the natural result that the so-called roads usually

Mar 1, 1912

By Rossiter W. Raymond

(Canal Zone Meeting, November, 1910.) THE death of Professor Blake removes the oldest of American economic geologists and mining engineers, and deprives this Institute of one of its, earliest and most illustrious members. To many of us it brings a personal loss also, the loss of a friend. William Phipps Blake was born June 21, 1826, in New York City. -His father, Elihu Blake, was a surgeon-dentist of eminence, a direct descendant of William Blake, who settled in the Massachusetts Bay Colony about 1630. He was prepared for college at private schools in New York, and entered the Sheffield School of Yale, where he was graduated as Ph.B. in the chemical course, class of 1852, the first graduating-class of the institution. In the same year he became chemist and mineralogist of the New Jersey Zinc Co., and chemist of chemical works at Baltimore, Md. In 1853, lie started the Department of Mineralogy of the World's Fair at New York City. In 1854, 1855 and 1856, he was mineralogist and geologist of the United States Pacific Railroad Surveys of Williamson, Pope, and Whipple, and for the War Department at Washington. His writings, during this period comprise reports on the geology and mineralogy of California and other parts of the Southwest, and constitute well nigh the earliest scientific accounts of the regions described. One of them. was a translation of the Resume and Field Notes of Jules Marcou, of Whipple's expedition. From 1856 to 1859, he was engaged in explorations of the geology and mineral deposits of North Carolina, :and other parts of the country. In 1859, he became editor and proprietor of The Mining Magazine. This was a monthly periodical, founded in 1853 by W. J. Tenny, who conducted it until 1858, when it passed into the hands of Thomas McElrath, a New York publisher, and appeared in May of that year as The Mining and Statistic Magazine, with the name of

Sep 1, 1910

By Geo. T. Lynch

PALEOLITHIC MAN, laboriously shaping a stone implement in his cave, discovered that the dust irritated his eyes and nostrils and hindered his labors, whereupon, muttering a few incantations, forerunners of modern profanity, he removed himself and his work outside. There, ignoring the jeers of the hairy ?old-timers,? he turned his back to the wind and resumed operations in comparative comfort. Thus originated the dust problem in the mineral industries, and its solution. Despite long familiarity with the annoyance, danger, and loss occasioned by dust, little progress was made in the engineering solution of its problems until recent years. Some advance can now be reported but too many traces of ancient tradition and practice still remain. Considerable published information is available but only a part of this is of proved accuracy and utility. The greater portion is either misleading, being derived from too few cases to be of general application, or entirely erroneous, originating in guesswork, legend, or individual inspiration, divine or otherwise. The engineer, confronted with a dust problem, has neither the time nor the special training required to extract the values from this mass of low-grade. It is, therefore, desirable that we attempt to correlate the known values and to put them into a form upon which actual progress can be based. This discussion is, then, for the benefit of that engineer, particularly the engineer in the mineral industries and more particularly in ore-dressing plants, and is merely a gathering of facts already known but difficult to segregate.

Jan 1, 1938