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By L. D. Jaffe, D. C. Buffum

The importance of temper brittleness in alloy steels has long been realized in Europe. In the United States recognition of its importance has developed within the last several years. Many brittle failures encountered in parts made of alloy steel are undoubtedly attributable, wholly or in part, to temper brittleness. These failures have occurred particularly at low temperatures, under shock loading, and in the presence of notches, restraints and combined stresses. It has been almost universally accepted that plain carbon steels are not susceptible to temper brittleness. As a result, considerable effort has been expended in attempts to discover the manner in which alloying elements introduce temper brittleness. It is desired to raise the possibility that plain carbon steels are not only susceptible to temper brittleness, but are much more susceptible than alloy steels, in the sense that they embrittle much more rapidly. It is suggested that previous views, (that plain carbon steels are not susceptible), are based upon an erroneous interpretation of the experimental results. Interpretation of Previous Data For many years the standard criterion for susceptibility of a steel to temper brittleness consisted of comparison of the energy absorption, in a notched-bar impact test at room temperature, of specimens that had received two heat treatments.' One specimen (or group of specimens) was quenched, tempered, and quenched from the temper. The other specimen (or group) differed only in having received an embrittlement treatment, which might consist of a slow cool from the tempering temperature, or of an isothermal hold in the range 45w550°C subsequent to quenching from the temper. If the energy absorption of the specimen receiving the embrittlement treatment was lower than that of the specimen not given this treatment, it was said that the steel was susceptible to temper brittleness. If the energy absorptions were the same, it was said that the steel was not susceptible. Several investigators2J found that plain carbon steels showed negligible difference in energy absorption in such tests (at least when their manganese content was below 0.60 pct), and concluded that plain carbon steels are not susceptible to temper brittleness. Recently the deficiencies of the criterion mentioned above have been pointed out.'-= The criterion now generally used for susceptibility to temper brittleness retains the heat treatments used in the earlier scheme, but instead of the notched-bar impact tests being made only at room temperature, they are made over a range of temperatures, covering the transition from ductile to brittle fracture. If the transition temperature of the specimens receiving the embrittlement treatment is higher than those

Jan 1, 1949

By John H. Melvin

The Omaha District, Corps of Engineers, has been doing subsurface exploration work for a number of years, both by contract and with its own forces. Certain practices and procedures concerning the recovery of large diameter cores have been developed which will be described in this paper. Geology Most of the drilling to date has been in connection with structures on the main stem of the Missouri River above Sioux City, Iowa. A wide variety of subsurface conditions has been encountered. The bedrock formations appear in regular order from the oldest to the youngest, traveling upstream; or in other words, the general regional dip is to the northwest. The oldest formation is the Carlile shale, a compaction or noncemented waxy shale of Cretaceous age. Because of its unce-mented, soft nature this shale has a tendency to grind or wash away when drilled. It also has a tendency to rebound or expand when the overlying pressures are removed. A 25-ft bed of sharp, friable sandstone called the Codell member is present near the top of the Carlile shale. This member is a cemented sediment, but in drilling, many of the sand grains are broken loose and exert extensive abrasive action on the core barrel and bit. Above the Carlile shale is the Niobrara chalk, a soft calcareous deposit with shaly horizons and some thin beds of bentonitic clay. The average thickness of this deposit is about 145 ft. It is soft enough to be sawed or bored with ordinary woodworking tools, yet is compact enough to be used as building block. The Pierre shale, the formation above the Niobrara chalk, is over 800 ft in thickness and is the most widespread material in the area. It is a dark colored, compaction shale containing numerous thin bentonitic clay seams and at certain horizons, hard manganese concretions. The shale has numerous faults and in addition, along the valley walls, has undergone considerable slumping. Joints, fault planes and slickensided surfaces are common features encountered in drilling and add to the difficulties of high core recovery. East of the Missouri River the bedrock is generally covered with from 100 to 200 ft of glacial till, composed of clays, silts, sands, gravels and boulders. The valley itself is filled with alluvial deposits, mostly of the sand and gravel sizes, and contains a buried preglacial or interglacial channel over 100 ft in depth. The overburden deposits require sampling in connection with engineering studies and must also be cased before the underlying bedrock can be cored. The diameter of the required overburden samples can thus have an indirect effect on the size of core recovered from the bedrock. West of the river, which in most cases is the western boundary of glaciation,

Jan 1, 1949

By George G. Thomas

IN April 1949, Newfoundland became the tenth province of Canada. It had been a Dominion of the British Commonwealth, though actual Dominion status had been suspended for some fifteen years. During that fifteen-year period the Government had been by commission. Throughout the regime of the Commission Government, a limited program of investigation of the mineral resources of the country was in progress. It was during this period that the investigation of the iron resources of Labrador by the predecessors of the Iron Ore Company of Canada began. Since Confederation there has been a marked change in the attitude of mining capital to the new province and a notable acceleration in the tempo of prospecting and exploration. There is no private Newfoundland capital available for mineral exploration. In the past, as now, capital must be attracted to the province. Prior to Confederation, Canadian capital had to cross the barriers of customs and immigration. American capital hazily regarded Newfoundland as part of Canada, with one notable exception, the American Smelting and Refining Company at Buchans. Buchans The most significant mining development in Newfoundland today is the property of the Buchans Mining Co. Ltd., a subsidiary of the American Smelting and Refining Co., located at the town of Buchans. Their milling operation produces lead, zinc, and copper concentrates by selective flotation, and also produces a small amount of gravity concentrate. Presently the mill treats, about 320,000 tons of ore per year. Production started in 1928 at 500 tons per day and has been raised over the years to the present figure of 1200 tons per day. Conventional prospecting methods uncovered the original deposit. It was first examined as a possible source of sulphur from pyrite. Geophysical prospecting and diamond drilling resulted in discovery of enough additional ore to warrant a large scale operation. Mining is by open cut methods. In addition conventional underground cut and fill stoping and square set stoping methods are employed. Between 850 and 900 men are employed at Buchans. Concentrates are shipped by rail to Botwood and leave the country through the port. Buchans Mining is currently investigating a Crown concession covering an area of approximately 6250 square miles, adjacent to the area of present operations. Aerial photographs have been made of the area, and geologic parties, supplied by plane, are in the field during the summer months. The concession lies south of the Falconbridge concession. The geology of the Buchans area can be divided into three groups. The first category is the oldest and called the Buchans Series. It consists of volcanic lavas, breecias and tuffs and underlies most of the Red Indian Lake Basin. The second is a group of igneous rocks such as granite and quartz porphyry intrusive in the volcanics. It makes for rough country north and west of Buchans. The third group consists of sills and dykes penetrating the lavas near

Jan 1, 1952

By Robert Anderson Cook

AS the margin of profit in the manufacture of iron continues to decrease, attention is called more and more to economies in every department. Beginning at the bottom, in the preparation of the ore at the mine, me notice a general tendency is towards the shipment of richer ores, securing to the mine-owner a better price per ton, which the purchaser is glad to pay by reason of the saving in freight of iron, and in the cost of reduction, which depends so largely upon the amount of fuel and flux, and the productive capacity of the plant. In other words, the difference in value between rich and poor ores is much greater than their relative percentages of iron indicates; because the barren material in a lean ore is not merely worthless, it is a positive source of expense, requiring transportation, handling, fluxing, smelting, and its due share of general expenses; in return for which it yields nothing and decreases the available capacity of a given plant and capital for profitable work. The enriching of the ore is done in most places by hand-picking, and in a few by wet concentration; but the managers of several magnetite mines in Sweden have been practically successful in doing it by machinery. The only magnetic separating machine which has actually taken the place of hand-picking was designed and patented by Mr. Jonas Wenström of Örebrö, Sweden. In this machine, which is illustrated in Figs. 1 and 2, Mr. Wenström has taken advantage of the property of soft iron to become magnetized by induction. The machine consists of a barrel made up of soft iron bars and some non-conducting material (usually wood), which is rotated around a stationary shaft by means of a cog-wheel. Inside of this barrel, on the shaft, is placed eccentrically a cylindrical electro-magnet, provided with a number of manges (N, S, Fig. I), between which wire is wound in such a manner that the flanges are of negative and positive polarity, being energized by a current passing through the wire coils from a small dynamo. As will be seen in Fig. 1, the flanges, N, S, are circular, and follow the internal contour of the barrel on the front side, while on the opposite side they are cut down to the line B, B' in Fig. 2. Hence the bars of the revolving barrel on the front side of the machine are mag-

Jan 1, 1889

FRED TURRELL GREENE Fred Turrell Greene was born in Brooklyn, N. Y., Nov. 22, 1872. His father, William A. Greene, was born in Providence, R. I., and his mother, Angenora Semlear, was born in Brooklyn, N. Y. Fred's early school clays were spent in Boston, whence his father moved to Canada in 1882. Attending first the Collegiate Institute in Toronto, .then the High School at Berlin (now Kitchener), Ontario, where he graduated, Fred progressed to the Toronto University and the Michigan College of Mines, at Houghton, where lie graduated in 1897. He secured employment almost immediately at Butte with the engineering force of the Boston & Montana Consolidated Silver Mining Co., under Chas. S. Batterman. In 1899 he went to Rossland, B. C., where he spent more than a year as mining engineer and assistant superintendent of the War Eagle Consolidated Mining and Development Co. and the Center Star Mining Company Ltd. Returning to Butte in 1900, he acted as assistant geologist for the Anaconda Copper Mining Co. until 1906, when he filled a similar position in St. Paul with the Great Northern Railway for about two years. From 1908 until his tragic death on Christmas day, 1917, his headquarters were in Butte, where he enjoyed an excellent reputation -as consulting mining engineer, with a rapidly widening circle of clients. During the past four years he had been consulting engineer for the Elm Orlu and other mines controlled by Hon. W. A. Clark, and was in charge of underground developments and law-suit preparations for the celebrated apex case between the Elm Orlu and the Butte & Superior companies. At the time of his death he was in charge of similar work for the Utah Metals Co., in connection with their mines at Bingham, Utah. He was also for some years active in the Coeur d'Alenes, as consulting geologist for the Federal and other companies there, and was considered an authority on this as well as the Butte district. Mr. Greene was unmarried, and is survived by his parents, a younger brother, who is in the army, and one sister, Mrs. James A. Hatch, of New York. Some of the most important and valuable ideas regarding the nature and origin of copper ores have originated in Butte, since that district is not only one of the greatest examples of mineralization known in any land, but has gone through a long course of mining litigation, and was, one of the first to be studied intensively by geologists. In connection with the early investigations, as well as with the most recent in that camp, Mr. Greene played an important part. His conscientious devotion to his duties and his intelligent handling of the problems presented for solution sufficiently explain the esteem in which he was held by his employers and his professional associates.

Jan 5, 1918

We the undersigned, being all persons of full age and citizens of the United States and a majority residents of the State of New York, desiring to form a corporation pursuant to the provisions of the Membership Corporations Law for the purpose of incorporating, as provided in Section 5 of Article I. of said law, the existing unincorporated association known as American Institute of Mining and Metallurgical Engineers, Incorporated, do hereby make, acknowledge and file this Certificate for that purpose, and do Certify as follows: I. That the American Institute of Mining Engineers is an unincorporated association organized and existing with the object of promoting the arts and sciences, connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained. II. That the persons duly appointed or designated to manage the affairs of said association are designated by the rules thereof Members of its Council; that the undersigned are all members of said Council as the same was constituted on the 29th day of December, 1904. III. That on said last-mentioned date a regularly called meeting of said association was held at its office in the Borough of Manhattan, City of New York; that thirty days before such meeting notice of the intention to incorporate said association was given by mail to each member thereof whose residence or post-office address is known; that at said meeting the following resolutions were offered, seconded and duly adopted by the unanimous vote of all its members then present, to wit: "Resolved, That it is the sense of the members and associates of the American Institute of Mining Engineers in general meeting assembled that it is desirable and necessary for the well being of said association and its members and for the furtherance of the objects for which the same has been formed, that said association incorporate under the Membership Corporations Law of the State of New York; "And Further Resolved, That the Members of the Council of this Association, or a majority thereof, be and they hereby are authorized, in accordance with the provisions of Section 5 of Article I. of the Membership Corporations Law, to incorporate this association for the same purposes for which it has been organized and conducted, in the manner provided in Article II. of said law;, "And Further Resolved, That the name of said corporation as hereby adopted by this meeting shall be American Institute of Mining Engineers; "And Further Resolved, That the said incorporators shall be named in the Certifi¬cate of Incorporation as directors of such corporation until its first annual meeting,

Jan 1, 1940

By John C. McDonald

This report is a continuation of an earlier one with a similar titlell to which the reader is referred for such details of procedure as do not appear here. A brief summary will be given of the objects and methods of the research at this time. It was pointed out in the previous paper that properties of magnesium alloys, as reported by different workers, often differ. This was thought to be due to differences in the preparation of the specimens tested. The ideal way to compare alloys would be to prepare each of them in so many ways that reasonable assurance would exist that the best properties of each alloy had been developed. The alloys would then be compared on the basis of these properties. The treatment actually given the alloys of these studies is necessarily a compromise with completeness. Nevertheless, enough treatments have been given so that a considerable degree of assurance exists that the properties obtained are representative of the alloy as such, and not merely of the manner in which it was worked and heat-treated. Procedure The alloys were cast in the form of cylindrical ingots, which were extruded into bar before being rolled. Some of the ingots were made in 2-in. diameter molds whereas all of the alloys of the previous paper were cast in 4.in. molds. For the larger ingots, the extruded bar was 2 by 0.140 in.; lor the 2-in. ingots, it was I by 0.100 in. Preliminary work indicated that strip rolled from both sizes of the bars would have substantially the same properties. The bar was rolled at some temperature in the range 400' to 800°F., for a total reduction of 50 per cent. The temperature and reduction per pass were so selected that no cold cracking occurred, but were such as to leave the metal in a semihard condition. The hot-rolled metal was annealed at several temperatures in the range 400' to 800°F.; it was also cold-rolled, and given solution and aging treatments. Two standard test bars corresponding to each treatment were pulled in tension, and the average was obtained. Twelve treatments, in all, were given each alloy. The properties of the annealed specimen having the highest percentage of elongation were selected to represent the alloy in the annealed condition. The properties of the cold-rolled specimen having the highest yield strength were selected to represent the alloy in the cold-rolled condition. These properties were then plotted against percentage composition by analysis. Smooth curves were drawn among the points, thus graphically averaging the results over the entire range studied. The percentage of elongation in the cold-rolled state was not plotted, since it was always low, and varied in an irregular manner with composition. Alloys Studied Magnesium-calcium Alloys.—Fig. I presents the results on the alloys of the rnag-

Jan 1, 1941

By Lewis W. MacNaughton

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Knox, Montague, Wichita, and Wil-barger. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, are usually modified by stratigraphic changes in the sediments. Excepting the fields in southeastern Baylor, southern Archer, and southwestern Clay Counties, all the fields within the district are on this Red River uplift. These exceptions, which have the same type of oil and gas accumulation as the other fields, are on the extreme north end of the Bend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas to Archer County. The larger part of past oil and gas production has come from Pennsylvanian strata, with less important amounts from the Permian, and minor but increasingly important quantities from the Ordovician. Developments during 1940 The encouraging outcome of exploration and development in Montague and Cooke Counties and generally greater activity throughout the district resulted in the drilling of some 1700 wells during 1940, about 350 more wells than were drilled in 1939. Approximately 1250 of these tests were completed as oil wells. Production likewise increased during I940 to the extent of 8 million barrels more than the 25 1/2 million barrels produced in 1939. In spite of this large increase in production, known oil reserves again increased substantially. As is usually characteristic of this district, the new reserves were from a large number of fields, none of which were of such magnitude as to be important to the oil industry. Nevertheless, the Fargo field, Wilbarger County, deserves mention as one of the more important discoveries in this district during 1940. Following seismic surveys, the hmerada Petroleum Corporation located its No. I Goodpasture in sec. 35, block IS, H. and T. C. R. R. Co. survey, and drilled it to a total depth of 6717 ft. This well was completed in July 1940 through perforations in the casing from a pay between 3230 and 3252 ft. for an initial production of 241.5 bbl. on an 8-hr. pumping test. Other potential producing horizons were found in the Pennsyl-vanian at depths of 3960 to 3995 ft., 4208 to 11.234 ft., 4407 to 4422 ft., and in the Ordovician at 6300 ft. Wells completed to date in the several Pennsylvanian horizons have an average daily potential of 600 bbl. of oil. Although no wells have yet been completed in the Ellenburger dolomite (Ordovician), the discovery well swabbed I5 bbl. per hour from this formation before plugging back for completion in an upper horizon.

Jan 1, 1941

By G. S. Hume

Production of petroleum and natural .gas increased in Canada in 1940 over the previous year. Alberta produced more than 97 per cent of the total Canadian production of 8,718,053 bbl. of oil, an increase for this province of nearly 12 per cent, whereas in Ontario and New Brunswick, where the production is relatively small, there was a slight decline. In Alberta the main producing field is Turner Valley, on the eastern edge of the foothills southwest of Calgary, and development continued in this field in 1940 with the completion of 36 wells, all of which obtained production. In the Red Coulce field, close to the International Boundary, near Coutts, no new wells were drilled and the seven producing wells showed a decline of 900 bbl. below the previous year. Also, in the Wainwright field of east central Alberta, four wells, yielding heavy crude oil, produced 4000 bbl. less oil than in 1939, owing possibly rather to discontinuous operation than to actual decline in potential yield. This decline was more than offset by production from a new field 40 miles northeast of Wainwright, at Borradaile, producing oil of 14" to I 5° A.P.1. There was a small increase in production during 1940 from the Del Bonita field, in southern Alberta, where the production is from two wells. The outstanding development of the year was the completion of Standard Oil Princess No. 2 well in the Steveville area, on the Plains 100 miles east of Calgary. This well was completed late in December with an initial flow1 of 520 bbl. of 26.3" A.P,I. oil, and 12,750 M cu. ft. of gas from the upper part of the Mississippian limestone. It has opened up a new field and given a further proof of the potentialities of the Southern Plains. The production of petroleum in Canada is shown in Table I. Since most of the yield comes from Alberta, the production is shown from the various fields in Table 2. The sale value of the petroleum produced in Canada in 1940 exceeded 11.1 million dollars, which is still somewhat less than the value of the natural gas production, shown in Table 3. Table i.—Production of Petroleum in Canada" Barrels Province 1939 1940 New Brunswick........ 20,101 21,161 Ontario............... 206,196 186,471 Alberta............... 7,595,000 8,493,237 Northwest Territories. . 17,013 8,493,23717.184 Total............... 7,838,310 8,718,053 Value............... $10,353,351 $11.113,000 0 Bureau of Statistics, Ottawa. Turner Valley, Alberta Turner Valley continues to be by far the largest producing field in Canada (details are given in Table 4), The limits of the Pr in- field are now Known. On the east the oil area is bounded by the gas cap, which in turn is cut off on its east side by a major overthrust fault; on the west, ii is defined by edge water at a level of 4roc

Jan 1, 1941

By John T. Norton, Robert W. Lindsay

A number of detailed investigations of the physical changes accompanying age-hardening have raised the question as to the possibility of some phenomenon preceding the actual process of precipitation. There is considerable evidence to indicate that in the first stages of the aging process there is a pronounced distortion of the crystal lattice. This is particularly marked in duralumin. It would be of considerable theoretical interest to know the nature of this distortion as compared with that produced in other ways and to find out whether, in supersaturated alloys, it is a necessary antecedent to the formation of a second phase by precipitation. It was believed that a study of the age-hardening char-acteristics of a normally aged alloy compared with one that had been mechanically distorted might supply some useful information on these points. In addition, information would be obtained regarding the effect of a mechanical distortion on any subsequent stage in the aging process. Duralumin was chosen as the material for this investigation because the various aspects of its aging behavior can be shown in detail by suitable variations of the aging temperature. Also, probably more work has been done on this class of alloys than on any other. In spite of the many published results, it was felt that the experiments would be significant only if all of the work were done on samples from the same source and if they were examined under identical experimental conditions. Previous Work The many studies of the mechanism of aging in duralumin have been more or less crystallized by a series of papers by Fink and Smith1~2~3 and a recent paper by Cohen.~ The former authors believe that a simple precipitation theory is adequate to account for the various phenomena

Jan 1, 1939

By H. R. Stahl

The disseminated lead district of Southeast Missouri lies 70 miles south of St. Louis. The only metal of economic importance in the ore is lead, but minor amounts occur of iron, zinc, copper, cobalt, nickel, silver and cadmium. These minor metals, as might be expected, tend to concentrate in both the flotation and table middlings. In the past, some zinc has been recovered by differential flotation. The silver and cadmium tend to associate with the zinc, and some recovery is made of these two metals at the smelter. The lead occurs as galena, or lead sulphide. The minor metals are also present as sulphides. The presence of oxidized lead is suspected, but has not been definitely proved. The gangue is chiefly dolomitic limestone, with small amounts of sandstone and shaly glauconitic and chloritic minerals. The ore contains about 3.25 per cent lead, occurring as galena disseminated through the gangue. Some of the galena is very finely disseminated, and the mineral in the gravity tailings, or chat; is seldom or never in the free state. The method of treatment of the ore has been evolved over a period of 75 years; hence probably is not far from correct. The milling processes have tended toward simplification during the past 15 years, but recoveries have never been sacrificed for the sake of simplicity. In many cases, simplification of flowsheets has led to better recoveries and operating economies. A simplified flowsheet is shown in Fig. I. The St. Joseph Lead Co. operates four mills in the Flat River district, with a normal total capacity of about 21,000 tons per day, divided as follows: Federal mill, 11,000 tons; Leadwood mill, 4500 tons; Desloge mill, 3400 tons and Bonne Terre mill 2400 tons. The methods of concentration used at these plants are similar in principle; they differ mainly in details and in the type and size of the equipment used. The process of concentration may be divided into five main steps; i.e., dry crushing, wet grinding, classification with its attendant desliming, tabling and flotation. A brief description of these processes will be given, noting important differences in the various plants, and also noting the more important changes or developments of the past few years. Dry Crushing The run-of-mine ore is hoisted in skips, the capacity of these skips ranging from 23/4 tons to 81/4 tons. At the Desloge plant, the ore is hoisted in 2-ton mine cars on self-dumping cages. All ore is hoisted at shafts adjacent to the various crushing plants, no ore being transported on the surface. Primary breaking at all the mills is accomplished with 9E Telsmith breakers. Preliminary screening is provided ahead of most of these crushers, either by station-

Jan 1, 1943

By Keith Leonard Sutherland

This paper is a study of the differential flotation of the sulphide minerals in the presence of salts of silver, lead and zinc. In practice, accidental activation due to these salts is more important than their use as reagents to replace copper sulphate. The general method of investigation has been based upon contact tests, the temperature of 35°C being chosen in conformity with earlier work. Potassium ethyl xanthate and potassium amyl xanthate were selected as collectors and pure sulphide minerals were used. The experimental procedure has been outlined in earlier papers and all solutions were kept carbonate-free.14 Contact, or spreading of an air bubble, at a mineral surface indicates the presence of an adsorbed collector film. Purity of Reagents The xanthates were purified in the usual manner.' Neither the cyanide nor the sodium hydroxide solutions contained sufficient carbonate to give a precipitate with barium chloride solution. The silver sulphate was prepared from pure silver nitrate by evaporation with concentrated sulphuric acid until there was no evidence of brown fumes, This solution was diluted and the difficultly soluble sulphate washed with water so that unchanged nitrate was dissolved. The resultant crystalline powder was pure white. The lead and zinc salts were prepared by dissolving especially pure lead and zinc in C.P. nitric and sulphuric acid solution and the crystals drained. The standard solutions were checked by titration. It was felt desirable to use the sulphate radical wherever possible, but since lead sulphate was insufficiently soluble for the purpose of the experiments, it was necessary to use some other lead salt. A.R. copper sulphate was used without further purification. Results The results are presented in the accompanying figures; the areas of noncontact (nonflotation) are shaded in Figs. 8, 9, 10 and 11; in the remainder they lie to the right of the curve. Zinc Sulphate The curves in Fig. I are to be compared with those for Fig. 2, for which zinc sulphate is absent. This comparison shows that the influence of the zinc ion is usually small. Its influence is more marked, however, for chalcopyrite in the absence of cyanide. The influence of zinc sulphate is also marked for copper-activated sphalerite, for which tests were made only in the "absence of cyanide. The results are of importance in the separation of pyrite from copper-activated sphalerite when zinc sulphate is added in the lead flotation section (p. 204 of ref. I). Sphalerite does not adsorb the collector (i.e., become floatable) under the conditions chosen.

Jan 1, 1943

By Arthur F. Taggart, Nathaniel Arbiter

The fact that the floatability of minerals with fatty-acid collectors changes as the pH of a pulp varies was utilized in the early days of flotation, when sulphuric acid was used with oleic acid to float sphalerite and galena. from gangues which themselves float with fatty acids in alkaline pulps. Gaudin1 showed that this difference in floatability is a regular function of the extent of the change in pH. The present paper offers an explanation of the phenomenon, and on the basis thereof sets up recommendations for control of soap-flotation operations. Experimental Parallelism between floatability of a mineral in a given environment and its contact angle in that environment is so well established,2 and the contact angle is so readily and rapidly measurable, that contact angles have been used throughout the experimental work to indicate relative floatability. Experiments comprised contact-angle measurements on a number of representative minerals and metals, and a variety of subsidiary tests designed to check and to amplify the contact-angle indications. Contact-angle measurements were made by the method described in detail by del Giudice.3 Sequence of procedure for determination of the points of Fig. I was: I. Polish specimen. Most specimens yielded zero contact angle after polishing; a few showed a slight "cling." Cling is characteristic of specimens that pit on polishing; it is due to a residue of organic contamination, originally on the particle surface, which persists in the pits. The cling did not change total contact angle after conditioning, and is not, therefore, additive in the upper part of the curves of Fig. I. It may have broadened the bases of the curves for the affected minerals slightly. 2. The specimen was next conditioned in soap solution for 5 minutes. 3. The conditioned particle was transferred, under conditions that precluded surface drying, to an aqueous solution of the pH desired and contact angle determined. 4. The particle was thereupon transferred, again without surface drying, to water. The confirmatory tests will be described at the places pertinent in the argument. Discussion of Results Gaudin and Vincent4 have shown that contact angles with heptoic acid as a collector decrease for a given specimen when the concentration of collector present falls below a certain value. A similar reduction in angle occurs with collector-conditioned particles that are visibly slime-coated, and varies roughly with the extent of coating. Since in the last case the reduction in angle is certainly due to reduction in the proportion of total conditioned mineral surface presented to the bubble, the authors believe that the same condition prevails in the first case cited, and that similar reduction in angle and floatability will occur whenever starvation quantities of collector are present, whether by design or by reason of excessive consumption.

Jan 1, 1943

By Basil B. Zavoico

The World War I1 spread to Russia on June 22, 1941, when the German Armies began their invasion. The Soviet industries, which were already engaged in a tremendous armament program, further accelerated the flow of munitions, and equipment and supplies for all purposes not directly military were either entirely eliminated or reduced to an absolute minimum. With the occupation by German armies of the Dniepr and Kharkov industrial regions, this trend was necessarily further accentuated. The oil industry of Russia, in consequence, was left to rely more and more upon itself, its own very limited manufacturing facilities, extensive repair shops and probably much used equipment out of order stacked in the warehouses. All evidence available to date points to the fact that the new situation not only did not affect the production either quantitatively or qualitatively, but, on the contrary, caused a larger flow of much needed fuels to the country's war machine, primarily by renaissance of both management and labor. The oil industry of the Soviet Union, left to depend entirely upon itself for equip ment and supplies, and even for new workers and technicians to replace those called into the services, did and is still doing a good and effective job. Since it could not hope for new equipment and parts and could not blame any other industry for the delays in delivery, it dragged out old machines from storage and repaired them in its own machine shops. Often such stored and used equipment was but slightly defective, waiting for some small part from factories in Central Russia, plants that now were either in German hands or entirely converted to the manufacture of munitions. More particularly, instead of the pipe that could not be taken to the Caucasus from Central Russia, casing reclaimed from abandoned or submarginal wells was used, or pipe from the abandoned or but slightly used pipe lines; and this practice is being continued even now on a large scale, to create an ample reserve for the duration of the conflict. Indirectly such a development was even an improvement on pre-war days, when many wells about to be completed had to wait for weeks, even months, for the arrival of new pipe, all blame then being placed outside of the industry on the factories in Central Russia. For the purpose of reclaiming equipment and pipe still usable, special crews were organized. The war also caused much quicker adaptation of certain American practices and introduction of many emergency measures, such as: removal of derricks upon completion of wells and the use of drilling equipment mounted on skids for rapid transfer from location to location—both of these practices, while standard in the U.S.A., being new in Russia; installation of simplified surface pumping units; substitution of wooden bearings in the surface pump equipment; completion of wells in the Ural-Volga district, where formations are hard and tight throughout the sedimentary column, without either casing or

Jan 1, 1942

By James Norman, Benjamin S. Lindsey

BaritE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the 'more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to 100 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, II.II per cent SiO², and 2.85 per cent R²O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of non-metallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is scparated. Laboratory Flotation Work Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1942

By H. C. Ray

ABOUT the beginning of 1930, coal preparation had reached the stage where the cleaning of coal by liquid or air had become the order of the day. Since that time many new preparation plants have been installed in spite of the years of depression in the coal industry, and this is indicative of a trend wherein the coal producer found it expedient to manufacture a cleaner product in order to compete with other fuels. It was also about 1930 that, because of the difficulties encountered with fine coal in cleaning plants, dust collectors came into use. Both cleaning plants and dust collectors, therefore, were much discussed at the engineering meetings of the early 1930's. During these meetings the many advantages to be gained through the use of dust-collecting systems were pointed out by Hebley,1 Appleyard2 and others. The great possibilities of new markets for this product were emphasized and discussed at the same time; however, the disposal of the collected dust remained a problem. Since the purpose of dust collecting is to improve the preparation and, consequently, the salability of the coal, it seems illogical to return the collected dust to any of the coal being prepared for market use, as is done in preparation plants that include dust-collecting systems. The logical thing is to dispose of the dust in some useful and practical manner outside of the tipple. As a practical matter, this can be done in one or both of two ways; either by consuming the dust at the mine's own power plant or by marketing the dust direct to the consumer. The latter method not only offers the greatest opportunities, but is the most important, because of inequalities that may exist between the quantity of dust collected and the consuming capacity of the mine's power plant. In considering the more important marketing possibilities, we are confronted immediately with the problems connected with the handling and transportation of so fine a material. It is this problem, rather than the problem of finding new markets, that has been responsible for the lack of progress in the matter of dust disposal. It is the purpose of this paper to point out again some of the potential market outlets, and also to describe an existing system of handling and transporting coal dust. To the best of the writer's knowledge, this is the first and only operation in this country that has handled fine-mesh coal in bulk 50-ton lots direct to the consumer. POtential Markets for Fine-mesh Coal Dust In general, the potential market outlets would include any operation of which the pulverization of coal is a necessary part. To be more specific, a few of the better known operations of this type must include: colloidal-fuel plants, briquetting plants, "sea coal" distributing plants, water-purification plants and, obviously, pow-

Jan 1, 1944

By J. F. K. Brown, E. E. Roecker

For three years The Hudson Coal Co. has used egg anthracite instead of coke in its foundry cupola. It has long passed the stage of being told it cannot be done—the metal would be cold, of poor quality, or the speed of operation would be low. From observation, from use and from test. we know that our metal is about average; the cast iron invokes no adverse comment from the machine shop and the speed suits our foundry requirements. We have there-iore resolved into practice anthracite combustion processes in an industrial furnace formerly using coke, under conditions suitable to our needs. When it comes to translating what we know into use in another cupola, however, where operating conditions may be different, or to explaining why, with seemingly the same conditions in our own cupola, we have attained sometimes a temperature of 2800° in the metal and at another time 2600°, or a speed of 5 tons per hour against 2 35 tons per hour, we cannot do it. We cannot do this because there seems to be an unbridged gap between laboratory ideas on combustion and practical ideas on com-bustiqn, which we have been unable to cross in terms understandable to us as practical consumers. This gap or bridge centers around the problem of how combustion actually takes place; and we believe it is controlled by two factors: (I) the character of the surface of the fuel and (2) the space provided and needed within which the oxygen of the air is allowed to or can act on that surface. It has long been contended on behalf of coke that porosity is an important factor in combustion, although, admittedly, there are two schools of opposing thought on this question, as revealed in technical literature. It has been understood generally that a light, porous coke is the best metallurgical fuel because there are more square inches of carbon exposed to the blast of air, therefore more useful carbon-dioxide reactions can take place in the given space between the entrance of the air and the point where useful work is done. It is now our general idea that the heavier and the harder the coal, the better the metallurgical fuel, provided the surface of that fuel is suitable for fast reaction with the oxygen. Time and Space A cupola is loaded in layers of fuel and iron. The horizontal line where the first charge of iron rests on the coal is the top of the bed coal. With us that is 22 in., usually, above the tuyeres where the air enters. This means 600 lb. of coal. Every subsequent coal layer is 100 to 125 lb. of coal, and that 100 to 125 lb. of coal melts 1000 lb. of iron at around 2700° in the ladle. This quantity of coal represents a 3-in. layer spread across the cupola. The question arises: If this 3 in. of coal will melt 1000 lb. of metal, why was it necessary to use 600 lb., or 22 in., of coal beneath and between the first charge of iron and the air entrance?

Jan 1, 1944

By Paul A. Schafer

BaLatoc mine, the principal gold-producing mine in the Philippines, is 10 miles southeast of Baguio, in the Cordillera Central of northern Luzon.' The region is a deeply dissected plateau, ranging in altitude from 3000 to 5000 ft. above sea level. The rocks consist chiefly of granodiorite, diorite, and remnants of metamorphosed sediments, cut by dikes of andesite porphyry and quartz-diorite porphyry. All are intruded by a volcanic breccia plug, oval in horizontal section, about 3200 ft. long and 2300 ft. wide, which is the north central part of the mineralized area. Three main vein systems have been developed (Fig. I): 96, 231 and 364, which strike about N.70°E. and dip 50° to 90°S. Each system is a braided zone consisting of many individual components. They are disturbed by a series of premineral faults or shear zones striking about N.4s°E. Twelve of these produce important effects on the persistence, character, and quality of veins. From west to. east the faults are named (after claims): Hog, Big Gun, Bull, Pine, Lolita, Bar No. I, Bar No. 2, Curt, Sun, Helen, Itoe, and Frog. They are early breaks formed prior to the N.70°E. vein fractures. Mineralization occurs on them but, with several prominent exceptions, they are too low grade to mine. A number of northwesterly striking faults complete the structural pattern. Although they are relatively abundant, the effect on the veins is so small that they do not present any problems in mining or development. All of these faults that have been observed are later than the N.70°E. veins and offset them to the left. Northeast Faults The early northeast faults* are notably continuous in spite of their small displacements, 20 to 100 ft. Frequently they appear so weak that their importance is masked and their identity clouded. The gouge along any of these faults may vary from exceedingly weak at one point to very strong at another point only a short distance away. In other words, the amount of gouge depends on the changes of attitude of the fault plane, and is no indication of the extent of the movement. Places where walls are spread apart are filled with gouge squeezed from tight places. Also, mineralization sometimes obscures fault gouges by replacement. The mineralization of northeast faults has produced several important ore bodies; namely, 231 west on On fault and 96 vein on the same fault. To a smaller extent, Lolita, Curt, Bull, Bar NO. I, and Sun

Jan 1, 1949

By H. Landsberg

The curriculum presented here is an outgrowth of discussions by the Committee on Geophysics Courses of the A.I.M.E. in previous years. It had to be a compromise between the desires voiced by employers of geophysicists, professional geophysicists and the possibilities at an average college. There one has to face the questions of the available teaching staff, the inertia of administrators and teachers set in their ways, and the red tape involved in modernizing antiquated curricula. It is, of course, not ideal to have colleges and universities lag Io years behind the times. Rather, instead of being prodded by industry, they should be ahead of industrial needs. There should also be a certain amount of leeway for the student in any college curriculum. All these points had to be considered in drawing up a curriculum, which, instead of being narrowly termed "geology" or "geophysics" was rather called "earth science." It gives the student a chance to specialize in one of the various branches represented by teachers on the faculty of The Pennsylvania State College, giving as options Geology (with subdivisions of Mineralogy and Paleontology), Geophysics, Geography, and Meteorology. Table iA represents the option of geophysics in the curriculum that envisages that a student may want to make his career in any of the fields encompassed by the American Geophysical Union or in geoexploration. This is, of course, only the start of an education that in most cases will have to be followed by graduate work for complete professional training. The outlined curriculum is definitely of an engineering type and is identical for all of the four options mentioned for the first two years. Specialization will start in the junior year but even thereafter the branches are kept as closely allied as feasible in order to permit a student to change from one tO the other (e.g., because of a different aspect in the mployment situation) with a minimum of additional work. Table IB shows the geophysics option according to subject matter, indicating the considerable amount of work in the fundamentals of mathematics, physics and chemistry with a liberal number of geology courses, and some engineering. The courses in the field of geophysics are limited—just two lecture courses as a general introduction and one field course, to permit the student a visualization of the correlation between mathematically analyzed physical data and the geological realities. Thesis work is considered essential to teach the student, while he is still in college, some things S. F. Kelly has mentioned as desirable: (I) following of instructions for somewhat independent work; (2) organizing of material, and (3) producing a readable report. This, together with the personal contact with the advising faculty member, will help in forming a student's personality. The seminar course attempts to get the student into the habit of reading current literature, so that he can keep abreast of the times.

Jan 1, 1946

By Rizo-Pairón Alfonso, A. M. Gaudin

PREVIOUS studies of activation in flotation have directed attention to the action of the activator on the mineral to be floated rather than to the relationship of the activator to the collector The latter phase of the problem, however, seems to have definite scientific, if not also practical, interest In the investigation reported in this paper, experiments were carried out, largely with quartz as subject, barium as activator, and oleate as collector The results obtained indicate that a I I ratio of collector ion to activator ion gives optimum results, and that a 2 I ratio almost fails to achieve activation and flotation Yet, a 2 I ratio would have been expected on stoichiometric grounds, had the coating been a normal salt of the activator ion with the collector ion, since barium is a divalent cation and oleate a monovalent anion To interpret and rationalize the observations, considerations of the crystal chemistry of quartz are helpful The point of view to which these considerations lead may be of general applicability to systems involving suspensions of solids in liquids, they confirm that an adsorbed coating is inescapable APPARATUS AND SUPPLIES The experimental work consisted in barium-ion abstraction tests, hydrogen-ion and hydroxyl-ion abstraction tests, flotation tests, and determinations of the surface of the crushed quartz The flotation machine was built according to the design of D W McGlashan It consists of a drill press in which the bit has been replaced by a stainless-steel impellor surrounding a stainless-steel stator, as in the Fagergren laboratory machine The air intake is controlled by a valve, and the cell consists of a beaker The quartz was obtained from vein quartz stored in large chunks It was first crushed to 20 mesh, then sized on a 28-mesh screen The 20 to 28-mesh size alone was retained for use This size was freed of coarse iron by passage through a Ball-Norton magnetic separator, bleached with boiling hydrochloric acid to remove residual abraded iron, washed with distilled water until the washings were thoroughly free of ferrous, ferric, and excess hydrogen ion, and stored in covered Pyrex beakers under water until used The barium was used as barium chloride, Baker's analyzed C P The oleate was used as sodium oleate It was prepared from sodium hydroxide, Baker's analyzed C P , and oleic acid purified by R R de Arellano3 in the laboratories at the Massachusetts Institute of Technology The purification procedure was elaborated from the recent researches of Brown and Shinowara 2 It consisted in (I) saponification of olive oil with potassium

Jan 1, 1942