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By George Kellock

Introductory The Alberta Provincial Government has contemplated a revision of the Mines Act for some time past, and it is understood that a definite decision has now been made to do this at the next session of the Legislature. The Operators' and Miners' organizations of the Province have been asked, or at least have been given the opportunity, to submit their views and ideas relative to the proposed changes. The operators have already drafted out a number of changes which they feel would improve the Act from the standpoint of safety and practicability, and this paper has been prepared so that the general membership of the Rocky Mountain Branch of the Institute, which is composed largely of the operating and certificated officials of the mines, might have an opportunity to discuss, criticize, and improve upon the suggested changes which the operators are putting forward.

Jan 1, 1929

By A. F. Taggart

THE following notes represent significant excerpts from a mass of records of experimental work done in the ore-dressing laboratory at the Columbia School of Mines during the years 1926 to 1928-inclusive. CLASSIFICATION OF EXPERIMENTAL WORK The experiments performed may be grouped for purposes of description under the following general -headings: I. Collecting agents. a. A method for quantifying collecting effect. b. Coating with undissolved collecting agents (oils) c. Action of dissolved collecting agents. II. Frothing agents. a. A method for quantifying frothing effect. b. Relation between frothing effect and chemical composition. III. Inorganic reagents. a. Methods of studying the effects of these reagents. b. Effect on slime dispersion. c. Effect on sulfides. SUMMARY OF THE ORIGINS OF PRESENT-DAY FLOTATION PRACTICE The first practicable, foolproof method of froth flotation was described in U. S. patent 835120, issued in 1906 to Sulman, Picard and Ballot, and in the equivalent patents in other countries. A number of less simple methods of producing the same result had been described previously in patent publications and otherwise.1 The reagents specified in all of these early patents were "oils" and, in addition, some inorganic substance, usually an acid. The quantities of reagents recommended and added were enormous when' compared with those used today.

Jan 1, 1929

By C. H. McNaughton

The Tennessee Copper Co. operated two mines in the Ducktown district during 1928. The Burra Burra mine is much the larger operation and is the chief source of the ore smelted and treated in the, company's smelter and acid plant rat Copperhill, 4.5 miles from Ducktown. This mine operates steadily and furnishes a regular output of about 40,000 tons per month. The Eureka mine is operated irregularly and produces a much smaller tonnage of high-sulphur ore the rate of output depending upon the demand for sulphur. During 1928 about 60 per cent of the combined output of these mines was shipped directly to the smelter, and the balance was concentrated before shipment in the flotation plant located near the mines. ACKNOWLEDGMENTS The author acknowledges the assistance of Lamar Weaver, Assistant mine superintendent of the Tennessee Copper Co, and of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the, preparation of this paper, U. S. Geological Survey Professional-Paper 139, by W. H. Emmons and F. B. Laney, has been drawn upon for information contained 'in the paragraphs on history and geology.

Jan 1, 1929

By Albert Sauveur

THE senior author of this paper has expressed the belief that when gamma iron transforms into alpha iron on reaching the A3 point, each gamma grain does not change bodily into one or more alpha grains but that the alpha phase forms first at the boundaries and along the crystallographic planes of the austenite grains.1 To quote: On cooling through the point A, at about 900° C., iron passes from the gamma condition to a. new allotropic form generally designated as alpha. This transforma¬tion, however, is not instantaneous. There are good reasons for believing that it begins at the grain boundaries and along the octahedral planes of the crystals and that it progresses until each grain of gamma iron is changed into a grain of alpha iron, the resulting structure being similar to that of gamma iron. Were it possible to retain at room temperature pure iron but partially transformed, it seems probable that a Widmanstättian structure, or rather, as later explained, a martensitic structure would be observed (Fig. 1), consisting of alpha iron at the boundaries and at the octahedral planes, and of a groundmass of gamma iron. In order to confirm, if possible, the accuracy of that view, a number of experiments were conducted. Polished samples of electrolytic iron were heated in a vacuum, maintained in the gamma range for several hours and quenched in different media. It was hoped by such means to produce and retain on the polished surfaces a pattern which would reveal the mechanism of the allotropic transformation. The samples were placed in evacuated quartz tubes, heated to 1000° C. and held 2 hr. at that temperature. The tubes were then immersed in the quenching bath. Iced brine and liquid air were used first. The polyhedral austenitic structure existing at the time of immersion was very clearly revealed (Fig. 2). This is generally ascribed to iron volatilizing at the grain boundaries.

Jan 1, 1929

By D. L. Thompson

Foreword The complete history and early development of the Sullivan mine was fully covered in a paper entitled 'The Development of the Sullivan Mine and Processes for the Treatment of its Ores', prepared by the staff of the Consolidated Mining and Smelting Company of Canada, and presented at the Annual Meeting of the British Columbia Division of the Institute at Trail in October, 1924. At a subsequent meeting at Blairmore, Mr. E. G. Montgomery read a paper on the mine, and in 1926 Mr. M. M. O'Brien brought the subject up to date at the joint meeting of the American and Canadian Institutes at Cranbrook. The present paper is necessarily based largely on these earlier accounts. Discovery and Early Development The outcrop was discovered in 1892 and the property was bonded and later sold to the Sullivan Group Mining Company, of Spokane. From 1896 to 1899, surface stripping and test pits (at A) around the outcrop exposed a vien of sulphides with varying amounts of lead and zinc. In some places, a 35 per cent lead ore carrying 15 ounces of silver was found. These lenses were of commercial value. With the completion of the Kimberley branch of the Canadian Pacific railway, in 1900, some systematic development was started. A shaft l00 feet in depth was sunk (at B). Shaft-house, boiler-room, and compressor-plant were erected, and a steam diamond-drill was put into operation.

Jan 1, 1929

United Engineering Trustees, Inc Engineering Foundation Engineering Societies Research Board Other Committees United Engineering Trustees, Inc. ARTHUR S. DWIGHT GEORGE D. BARRON J. V. N. DOER Engineering Societies Library Board ROBERT PEELS PHILIP W. HENRY GEORGE C. STONE JOSEPH E. POGUE The Engineering Foundation H. C. BELLINGER GALEN H. CLEVENGER J. V. N. DORR

Jan 1, 1929

By J. J. Jakosky

All electrical geophysical methods depend for their operation upon the effects produced by the flow of an electric current. By studying these effects it is possible to predict the general axis of current flow. The greater flow of current is in the path of greatest effective conductivity; and since the effective conductivity of a mineralized zone is different from that of its surrounding envelope (usually much greater), it is possible to locate such a mineralized zone by the distribution of current. Due consideration must be given, of course, to geological structure, to type of mineralization, and to other factors. A number of methods are used to cause this flow of current, and various methods arc available for detecting the presence of such current flow and for studying its effects. In a rather detailed way, this paper will discuss the theoretical and practical phases of the inductive methods of geophysical prospecting. Electromagnetic Generation of an Electeomotive Force The inductive method is so named because the current flowing in the conductor is obtained by electromagnetic induction, instead of by the use of ground electrodes through which a current is passed as in the applied potential systems, or by direct contact with the orebody. An alternating current flowing in a coil will create an electromagnetic field around the coil. This field will have the same frequency as the current and will radiate or travel outward from the coil in closed magnetic or flux circuits. These flux circuits (in air or a homogeneous medium) will be perpendicular to the plane of the coil and will extend or travel outward with uniform velocity in every direction. Maximum feld exists in the plane of the coil. Such a coil used for transmitting or as the "energizer" will exhibit similar figure-eight characteristics to those exhibited by the direction-finding coil which will be described in detail later.

Jan 1, 1929

By Edward P. Barrett

[Iron oxides, when reduced at temperatures below 900° form a dark gray substance, very porous bait otherwise in almost the same form as the original particles. In the temperature ire range of 1,000 to 1,100° the product is pertly sintered but still shows the outlines of the original particles. Those products are known as "sponge iron." At temperatures of 1,100 to 1,2000 the metallic iron begins to flow together and to a semifused, pasty, porous mass called a "bloom," which can he worked under a hammer to form a product similar to wrought iron; it contains slag inclusions and is too low in carbon to make steel. If the temperature is 1,300 to 1,300°, part of the iron will fuse enough to absorb more carbon. The dissolved carbon lowers the melting point and still more carbon is absorbed. The melted portion acts a flux for the unmelted metallic particles until the entire mass becomes a high-carbon fluid known as "cast iron." Sponge iron was probably the form in which the first iron was recovered from the ores. As early as the eighth century the Catlan forge3 developed into a low-shaft furnace known as the "high bloomary," in which iron eras produced in the form of a pasty mass. In 1340 the first blast furnace was built in Belgium. The greater part of the iron was made into wrought-iron blooms by crude puddling processes. Charcoal was used as the fuel until tie latter part of the 17th century when coke was used in England. In 1865 Bessemer built his first converter in. England, and within a few years the Siemen's regenerative open-hearth furnace was developed, also in England. Enormous expansion in the metallurgy of iron followed. The idea of "direct processes" for the production of iron arid steel has persisted throughout all this time. The production of steel from sponge iron has theoretical advantages over the present-day standard methods, and handreds of so--called "direct processes" have been proposed or tried during the past century.4]

Jan 1, 1929

By J. A. Allan

The utilization of natural deposits of salt is one of the oldest industries in Alberta. In 1820, Sir James Richardson visited Salt river, and in the same year D. W. Harmon states chat "clown Slave river, there are several places, where almost any quantity of excellent dean white salt may be taken, with as much ease as sand along the seashore. From these places the greater part of the northwest is supplied with this valuable article". This reference is to the salt chat occurs around springs on Salt river at the northern boundary of the Province. This and other occurrences will be described later in this paper. It is not on account of the development of salt and gypsum in Alberta chat this paper has been prepared, but rather to draw attention to the widespread distribution of salt-bearing and gypsum-bearing rocks, and to the stratigraphic importance of these rocks . The origin of the deposits of salt, gypsum, anhydrite, and dolomite is discussed, and the economic significance of these minerals is considered. There is no salt production reported from Alberta in 1928.

Jan 1, 1929

By W. J. Rooney, James Fisher, W. O. Hotchkiss

During the summer of 1927, the Department of Terrestrial Magnetism of the Carnegie Institution of Washington joined with the Michigan College of Mining and Technology in conducting a series of earth-resistivity measurements in the Michigan copper country. The geological structure in this section is quite varied and fairly well known. The purpose of the investigation was to discover the correlation between the variations in electrical resistivity of large masses of soil and rock in place and the geological structure below the surface. The work done may be roughly divided into two parts: (1) Measurement and study of the variations in resistivity with depth, or with volume, to establish such general relations as exist between the two; and (2) the determination of the specific resistivity of various formations in order to make available more fundamental data which may aid in the interpretation of the results of the former type of measurement. A report by Mr. Rooney, which gives in detail the measurements made and the results obtained, forms the basis for this article. Measurement and Study of Variations in Resistivity The possibility of applying data from measurements of the physical properties of earth material to the study of the geological structure has long been recognized, and a number of methods for determining the position and character of concealed rock strata by means of seismic, gravitation, magnetic and electrical measurements made on the surface are being used with varying degrees of success. One physical property which varies widely for different materials, and hence affords an opportunity for distinguishing between them, is their electrical resistance. Locations • were selected where the geological structures were well known and where the depths to the water level and bed rock had been determined by drilling. The problem was to determine the value of measurements of resistivity and its variations as indications of the geological structure below the surface.

Jan 1, 1929

By Forrest A. Kerr

Northern British Columbia is a term which probably conveys to various individuals quite different meanings. To the average person it signifies an area of indefinite size and indefinite position which may start at Prince Rupert, Stewart, or somewhere else, and end at Alaska or .the Yukon. Many people, in their conception, fail to encompass in their mind's eye that vast tract of land lying ~o the east of the panhandle of Alaska. Few realize that the area north of an east-west line through Stewart represents more than one-third of the Province and is, of course, the part most appropriately designated as northern British Columbia. This section, more especially the northernmost 100,000 square miles, from political, geographic, and economic viewpoints stands isolated perhaps more than any other part of British Columbia. Unlike the rest of the Province, it has no coast line, being cut off from the Pacific ocean by a narrow strip of Alaska. It is bounded on the north by the Yukon, and on the east by Alberta. In the south this northernmost 100,000 square miles is limited by a divide of rugged mountainous country separating the drainage basins of the Stikine and Liard rivers from those to the south.

Jan 1, 1929

By G. R. Hopkins

The average gravity of the total crude petroleum produced in the United States during; the year 1927 was 32.2° A. P. I., or 0.864 in terms of specific gravity. A similar study, made by the U. S. Geological Survey in 1921, gave the average gravity at that time as 32.0.° To one who is accustomed to thinking of crude petroleum in terms of Oklahoma-Kansas and North Texas trades it may be surprising that the average gravity for the entire country is no higher than 32.20. The chief reason for this apparent discrepancy lies mainly in California production, which in 1927 amounted to over 25 per cent of the total, but which had an average gravity of only 24.10. A factor of less importance was Arkansas, which, though on the decline as a producing State, exerted a material effect by reason of its average gravity of 21.6°, the lowest for any State. In view of the heavy production of light crude in the Seminole area of Oklahoma during 1927, it would appear that the average gravity should have shown more than a 0.2 per cent gain over 1921. That this did not occur was due to the fact that in the interim between 1921 and 1927 important heavy oil discoveries were redo, notably the Smackover field of Arkansas.

Jan 1, 1929

By U. C. Tainton

FOR the last 15 years lead has been the standard material for anodes in electrolytic zinc production and it has been generally accepted that this lead should be as free as possible from impurities. Laist1 says, "Next in importance to the purity of solution is the purity of the electrodes and tank lining material. The purest lead obtainable should be used for anodes." The same conclusion is expressed by Ingalls2 and by two German investigators who say that experiments have demonstrated that the purer the lead, the greater is its resistance to corrosion during electrolysis.3 Pure lead, however, while the best material hitherto available for anodes, is not entirely free from objection. The plain lead anode gradually disintegrates under electrolysis, so that the life of an anode, say ¼ in. thick, is frequently not more than two years. Part of the lead from the anode finds its way to the cathode, lowering the purity of the deposited zinc and decreasing the hydrogen overvoltage. The rest of the lead that comes from the disintegration of the anode goes into the manganese dioxide which is precipitated in the cells, rendering unsaleable what might otherwise be a valuable by-product. Yet a further disadvantage of plain lead anodes comes from their tendency to bend or buckle during electrolysis, as a result of intercrystalline oxidation. This makes it necessary to use a fairly wide spacing between anode and cathode to avoid short circuits, and thus leads to a higher power consumption than would otherwise be necessary. The power consumption is also affected by the high decomposition voltage at a lead peroxide surface.

Jan 1, 1929

By James Terry Duee

No important producing developments took place in Colombia during the year 1928. This was at least partly due to the paralysis of operations by the passage, during the latter part of 1927, of a law which was regarded by the oil companies as confiscatory and unjust, and the promulgation of exceedingly stringent regulations of this law under decree No. 150, published Jan. 28, 1928. This decree, which contained 24 articles, practically prevented not only producing operations by the oil companies but even such activities as geological explorations and surveying, as severe fines were imposed for the possession of maps not registered with the Ministry of Industries. Both this regulatory decree and the law were subject to attack in the courts by several of the oil companies. The regulatory decree was suspended May 22 by Presidential proclamation, until the suits against it are decided by the Supreme Court and Council of State. Though another law was introduced into the Colombian Congress at a later date, no action was taken on it, and at the time of the writing of this paper, it would appear that no oil bill will pass the Colombian Congress during the present session. The Barco concession, which was revoked in February, 1926, still continues an unsettled matter, although there have been rumors that the government was attempting to come to some decision on this rather difficult question. A hopeful sign toward the close of the year was the settlement of negotiations with the Tropical Oil Co. over the acceptance of the payment for royalties due the government from that company. This settlement, which covered a royalty on crude oil produced from June 30, 1926 to June 30, 1928, represented a cash payment for approximately 3,000,000 barrels. It is to be hoped that during the coming year the Colombian government will see its way clear to clarify its position on petroleum legislation. A good augury for the future was the statement made by President Abadia Mendez on New Year's Day, in which he courageously admitted the errors of previous legislation and said, regarding oil, "Very soon

Jan 1, 1929

By T. D. Thomas

CONTENTS PAGE T. D. Thomas-Misfires in Anthracite Coal Mines 3 W. H. Forbes-Misfires in Bituminous Coal Mines 12 A. W. Worthington-Misfires in Non-metallic Mining (Limestone) 18 Misfires in Anthracite Coal Mines BY T. D. THOMAS,* LANSFORD, PA. (New York Meeting, February, 1929) IN THIS paper, major attention is given to misfires in mines where electric multiple shot-firing is the system used. Misfires are sometimes caused by one action or condition and at other times by a combination of two or more. They may be divided into two classes: (1) those caused by workers in the mines, (2) mechanical or manufacturer's causes. The second cause will be discussed first.

Jan 1, 1929

By McHenry Mosier

This paper describing mining practice at Morenci, Ariz., is one of a series of articles on mining method, and practice in the various mining districts in the United States. At present (1929) practically all the mineral production in the Morenci district is from the Humboldt mine of the Morenci Branch, Phelps Dodge Corporation. The mining method used is adapted to the type of ore body being exploited; it has been developed by adopting methods used elsewhere and making necessary changes to fit local conditions. Improvements in current practices are still being made.

Jan 1, 1929

By Ulick Evans

I SHOULD like to commence by saying how much I appreciate the honor which the American Institute of Mining and Metallurgical Engineers has done me in inviting me to visit your country, and to deliver this lecture before you. In choosing a subject, and in deciding what to include and what to omit, I have endeavored to discuss as far as possible work carried out recently in Europe with which you may not be unduly familiar. It would be poor return for your hospitality, and a mistaken sort of compliment indeed, if I were to load the lecture with accounts of researches 'carried out in your own country-researches with which you are probably better acquainted than I. Not that I have in any way excluded work done on, this side of the Atlantic from my survey; one would indeed find it difficult to write on this, or on any other branch of science, without mentioning American work. But I have endeavored as far as possible to concentrate on aspects of the case which will, I hope, be comparatively fresh to you, and I feel fairly certain that this will be in accordance with your own wishes. If a strip of iron is heated strongly at one end, the other end remaining cold, there is produced over the heated portion a layer of oxide scale, the thickness of which diminishes steadily with the distance from the hot end. Somewhere in the middle of the strip, the thickness of the oxidized layer will become comparable .to the wave length of light, and over this region the thin films give rise to a series of beautiful interference tints, commonly known as "temper colors." The colors are caused by the fact that two trains of light waves are reflected respectively from the outer and inner surfaces of the oxide film, .and the possibility arises that the "crests" of one series of waves may coincide with the "troughs" of the other, thus diminishing the intensity of the light of some particular wave length. The state of affairs in this part of the strip is shown diagrammatically in Fig. 1, in which the film thickness is enormously exaggerated, of course, in comparison with the length of the strip; the

Jan 1, 1929

By Henry Louis

THE work performed by, the Royal Commission on Mining Subsidence is likely to prove of permanent value, less perhaps for the conclusions it has reached and for the recommendations it has based upon these than for the admirable exposition which it affords of the law concerning mining subsidence and of the legal status of the person who has suffered damage by reason of such subsidence, as also of him whose working has caused the damage. The Commission was appointed by Royal Warrant in the middle of 1925 and delivered its final report in the middle of 1927. The terms of reference to the Commission were as follows: "To consider the operation of the law relating to the support of the surface of the land, and of buildings or works on or under the surface, by underlying or adjacent minerals; to enquire into the extent and gravity of the damage caused by subsidence owing to the extraction of minerals and the incidence of the resulting liability; and to report what steps should be taken, by legislation or otherwise, to remedy, equitably to all persons concerned, any defects or hardships that may be found to arise in existing conditions."

Jan 1, 1929

By A. G. Taylor, H. P. Ehrlinger, U. C. Tainton

FOR the last 15 years lead has been the standard material for anodes in electrolytic zinc production and it has been generally accepted that this lead should be as free as possible from impurities. Laistl says, "Next in importance to the purity of solution is the purity of the electrodes and tank lining material. The purest lead obtainable should be used for anodes." The same conclusion is expressed by Ingalls2 and by two German investigators who say that experiments have demonstrated that the purer the lead, the greater is its resistance to corrosion during electrolysis.3 Pure lead, however, while the best material hitherto available for anodes, is not entirely free from objection. The plain lead anode gradually disintegrates under electrolysis, so that the life of an anode, say 1/4 in. thick, is frequently not more than two years. Part of the lead from the anode finds its way to the cathode, lowering the purity of the deposited zinc and decreasing the hydrogen overvoltage. The rest of the lead that comes from the disintegration of the anode goes into the manganese dioxide which is precipitated in the cells, rendering unsaleable what might otherwise be a valuable by-product. Yet a further disadvantage of plain lead anodes comes from their tendency to bend or buckle during electrolysis, as a result of intercrystalline oxidation. This makes it necessary to use a fairly aide spacing between anode and cathode to avoid short circuits, and thus leads to a higher power consurnption than would otherwise be necessary. The power consumption is also affected by the high decomposition voltage at a lead peroxide surface.

Jan 1, 1929

By Walter Herd

Fox the past eight years No. 2 mine of the Cumberland Railway & Coal Co., Springhill, Nova Scotia-a subsidiary of the Dominion Coal Co., Ltd.-has had an unenviable reputation for bumps. As the workings extended in certain directions under a greater cover, these bumps increased in severity and it became apparent that some change in the system of extraction was necessary if the mine was to continue to operate. In September, 1924, following several fatalities resulting from bumps, the Mines Department of Nova Scotia requested from the U. S. Bureau of Mines the services of George S. Rice, Chief Mining Engineer of the Bureau, to report on the conditions then prevalent in No. 2 mine, Springhill. This request was promptly and courteously granted. Mr. Rice made a full investigation and a comprehensive and helpful report, which is embodied in the 1924 Annual Report of the Department of -Public Works and Mines, Nova Scotia. Prior to 1925, the room and pillar method was employed and in January of that year (there being a cessation of work from March to August due to labor troubles) longwall retreating on the west side, on a limited scale, and in a small section on the east side of the mine was started. The major portion of the east side was not operated on this system till August, 1926, as there was developed a considerable area ready for pillar extraction between an arbitrary boundary and a point up to which bumps of any consequence, had not been experienced. In the interval development work for longwall retreating below the 5900-ft. level was vigorously- pushed. This longwall retreating system was suggested by Mr. Rice as a possible remedy and was heartily endorsed by the company officials. This paper describes the conditions and happenings subsequent to Mr. Rice's report and more especially the results with the longwall retreating system of mining under the peculiar circumstances pertaining to mining. No. 2 Seam, Springhill, at depth, and records the 'conclusions which experience with several severe bumps under this mode of extraction would suggest. Except where necessary to make the paper intelligible as an entity any duplication of Mr. Rice's report will be avoided.

Jan 1, 1929