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By John J. Collins

[CONTENTS PAGE Purpose and scopeI Core samplingI Sludge sampling.....7 Combining core and sludge assays13 Deviation and surveying of drill holes17 Conclusions24 Acknowledgments25 Bibliography25] PURPOSE AND SCOPE The purpose of this paper is to review a few of the problems involved in the interpretation of diamond-drill core and sludge samples, with the hope that it will stimulate discussion and bring forth some of the information on the subject that has been accumulated by various organizations. The release of these data would benefit the mining industry as a whole. Particularly valuable would be the details of drilling programs that have been tested by actual mining operations, as most of the available published material is unsupported by production records. The scope of this paper is limited to a few of the commonest problems of interpreting diamond-drill core and sludge samples and the deviation of holes. It does not include the description of routine operations performed by the drillers, nor the estimation of ore reserves. The methods of calculating reserves have been described 25,26,31,32.50,65 but more information is needed on the results shown by actual mining operations. CORE SAMPLING The accuracy of diamond-drill-hole sampling depends in large measure on the percentage of core recovery. As a general rule, the longer the run, the poorer is the recovery. Although the longer runs allow cheaper drilling costs, the determining factor should be the percentage of recovery desired. The problem is one of balancing accuracy against costs. Holes of larger diameter may show improved recovery, except as Joralemon* points out that there are some conditions in which small holes give better core recovery than large holes. This is particularly true, he says, in rocks like shattered quartzite, where larger core tends to break in angular fragments and grind up, while the diameter of smaller core is less than the distance between joint planes and grinding is not so serious. In a large measure the length of the sample run should depend on the type of deposit. Favorable drilling may allow uniform sample runs of 5 ft., 10 ft., or perhaps 20 ft. In veins or beds of relatively narrow widths and changing characteristics, however, the ore zone may be overrun and ground in a core barrel full of waste rock. Generally it is desirable to break the sample at a change in the rock or ore. Such a change, often indicated by a color change in the sludge water, should be a signal for the driller to make a "dry" block and to pull out that run regardless of the length. Such a procedure permits the segregation of waste from ore samples so

Jan 1, 1946

By John J. Collins

Page Purpose and scope..................... 521 Core sampling......................... 521 Sludge sampling....................... 527 Combining core and sludge assays ...... 533 Deviation and surveying of drill holes. . . . 537 Conclusions........................... 544 Acknowledgments...................... 545 Bibliography.......................... 545 Purpose and Scope The purpose of this paper is to review a few of the problems involved in the interpretation of diamond-drill core and sludge samples, with the hope that it will stimulate discussion and bring forth some of the information on the subject that has been accumulated by various organizations. The release of these data would benefit the mining industry as a whole. Particularly valuable would be the details of drilling programs that have been tested by actual mining operations, as most of the available published material is unsupported by production records. The scope of this paper is limited to a few of the commonest problems of interpreting diamond-drill core and sludge samples and the deviation of holes. It does not include the description of routine operations performed by the drillers, nor the estimation of ore reserves. The methods of calculating reserves have been described,25,26,31,32,50,65 but more informa- tion is needed on the results shown by actual mining operations. Core Sampling The accuracy of diamond-drill-hole Sampling depends in large measure on the percentage of core recovery. As a general rule, the longer the run, the poorer is the recovery. Although the longer runs allow cheaper drilling costs, the determining factor should be the percentage of recovery desired. The problem is one of balancing accuracy against costs. Holes of larger diameter may show improved recovery, except as Joralemon* points out that there are some conditions in which small holes give better core recovery than large holes. This is particularly true, he says; in rocks like shattered quartzite, where larger core tends to break in angular fragments and grind up, while the diameter of smaller core is less than the distance between joint planes and grinding is not so serious. In a large measure the length of the sample run should depend on the type of deposit. Favorable drilling may allow uniform sample runs of 5 ft., 10 ft., or perhaps 20 ft. In veins or beds of relatively narrow widths and changing characteristics, however, the ore zone may be overrun and ground in a core barrel full of waste rock. Generally it is desirable to break the sample at a change in the rock or ore. Such a change; often indicated by a color change in the sludge water, should be a a for the driller to make a "dry" block and to pull out that run regardless of the length. Such a procedure permits the segregation of waste from ore samples so

Jan 1, 1946

All the Technical PUBlications and Preprints published in 1932 are available at Institute headquarters. They are also on file in public, university and technical libraries and, when so indicated in the list, may be found in the Transactions. Copies of the Technical Publications have been mailed to those members of the Institute who are registered in the different classes: A-Metal Mining; B-Milling and Concentration; C-Iron and Steel Division; D-Nonferrous Metallurgy; E-Insti-tute of Metals Division; F-Coal Division; G-Petroleum Division; H-Nonmetallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting. Other members may obtain copies by writing to the Secretary. Copies of Preprints may also be obtained from the Secretary's office. Additional copies are sold at the rate of 1 cent per page; minimum charge, 25 cents. Nonmembers may purchase the papers at the prices mentioned. Metal Mining Technical Publi- Title Author Meeting Trans. cation Volume No. and Page* 484-A.45 Propeller Type Mine Fan at Moose A. S. Richardson New York 102, 88. 95 F.52 Shaft. Butte. Montana (13) Feb.. 1932 487-A.46 Progress in the Improvement of Max H. Barber New York. Methods and Equipment at Feb., 1932 Open-pit Iron Mines on the Lake Superior Iron Ranges (9) Pre. Sand Filling through Pipes and Lucien Eaton New York, 102, 33, 41 Boreholes (9) Feb., 1932 Milling And Concentration 445-B.37 Soap Flotation of the Nomulfides Will H. Coghill New York. H.19 (18) J. Bruce Clemmer Feb., 1932 461-B.38 Principles of Flotation—An Experi- I. W. Wark New York. mental Study of the Effect of A. B. Cox Feb.. 1932 Xanthates on Contact Angles at Mineral Surfaces (48) Iron and Steel Division 447-C.81 Electrochemical Potentials of Nitri- Shun-ichi Satoh New York, fied Steels (31) Feb.. 1932 450-C.82 Reaistanoe of Iron-aluminum Alloya N. 9. Ziegler New York. 100, 267. 670 E.143 to Oxidation at High Tempera- Feb., 1932 tures (8) 451-C.83 Pressure Welding of Low-carbon C. H. Austin New York. Steela with Theoretical Con- W. S. Jeffries Feb.. 1932 siderations on the Mechanism of Such Welding (42) 453-C.84 Inclusions—Tbeir Effect, Solubility C.E.Sims New York, 100, 154, 176 and Control in Cast Steel (24) 0. A. Lillieqvist Feb., 1932

Jan 1, 1932

By ROBERT. RICHARDS

I. INTRODUCTION The object of this paper is to enlarge the field of settling velocities treated by me in my former papers, Close Sizing Before Jigging, and Sorting Before Sizing.' There seemed need of work both on coarser and on finer sizes. Messrs. A. Sidney Warren and M. L. Nagel undertook the investigation for the coarser sizes, from 12.85 mm. down to 2.05 mm. diameter. Their work, because of the closer spacing and because of the increased number of observations and consequent stronger averages, called for a revision of the former work. Messrs. G., A. Barnaby and Ralph Hayden undertook this part of the work, from 2.49 mm. down to 0.28 mm., which is near the limit of sifting. Their work covers the ground much more minutely and comprehensively than the former papers. There remained to be covered the portion of the field too fine for investigation with the sieves. This part, covering the range of grains from 0.48 to 0.03 mm., was undertaken by Mr. E. S. Bardwell. For it he used the elutriation method. II. THE FIRST, OR COARSEST, SECTION OF THE FIELD. The first desideratum in this investigation was a series of sieves for sizing the sands preparatory to making the tests. It became necessary, therefore, to decide on a sieve-scale for this purpose. A sieve-scale is a series of sieves in which the dimensions of the holes of the successive members form a series increasing by a. definite ratio. There are three natural sieve-scales : 1, progressing by doubling the width of the hole for each suc-

May 1, 1907

By W. E. Wrather

SERIOUS consideration was given by the Petroleum Division to a wide variety of subjects, during six busy sessions at the Annual Meeting. Beginning with a joint session on engineering research and production engineering, Tuesday afternoon, conducted by E. A. Stephenson and H. C. Fowler, problems of petroleum technology, domestic and foreign production, proved oil re- serves, economics, and stabilization were mooied almost without interruption until nearly everyone was "talked out,' and the meeting was adjourned at the end of the annual Petroleum Division dinner, late Thursday night.

Jan 1, 1933

By E. A. Anderson

THIS seems to be the year for superlatives in A.I.M.E. meetings. The programs of the various Divisions and Institute committees offered an abundance of interesting and valuable information in the form of technical papers, symposia. and lectures to large and interested audiences. The Institute of Metals Division may hold up its head with pride for its own program. With six technical sessions, three full-day symposia, and the annual I.M.D. dinner, four meeting days were not enough and many simultaneous sessions were required. The quantity and quality of the paper were equaled by the numbers and interest of those attending.

Jan 1, 1944

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Jan 1, 1946

By JOHN JERMAIN

In my opinion, the explanation of the fuel-requirements involving the conception of heat available and necessary above a critical temperature, as advanced by Johnson 1 and elaborated by Howe, Raymond and others,2 affords a theoretically correct basis for such an accounting. It is the purpose of this paper to set forth a first crude attempt to construct a formula which shall show quantitatively the relation between the various factors affecting fuel-economy, and afford a means of comparing the enormous amount of data on the fuel-consumption of various blast-furnaces, at various times and under various conditions of operation. I have also applied this formula to a large number. of individual cases, and have, by its means, compared the furnace-practice of several important iron-making districts. II. DERIVATION OF FORMULA FOR FUEL-REQUIREMENTS. The general expression for the fuel-requirements of the blast-furnace, which I believe to be theoretically correct as to form, is as follows Carbon per ton of iron = Heat per ton of iron necessary in hearth above Tc./Heat per pound of carbon available in hearth above Tc. XFactor of rate of driving. +Carbon dissolved by CO2 of flux. +Carbon dissolved incidental to reduction of ore. + Carbon dissolved in pig-iron. (NOTE.-Tc = critical temperature.) Since, according to Johnson's theory, fuel-economy is usually limited by heat available and necessary in the hearth, rather than by the total heat supplied and necessary, we may write Carbon needed in hearth = Hn/Ha in which Hn is the heat per ton of iron necessary in the hearth above some critical temperature, and Ha is the heat per pound of carbon available in the hearth above this same critical tem¬perature. 1 Trans., xxxvi., 454 (1906). 2 Trans, xxxvi., 792 to 798 (1906) ; Trans, xxxvii., 216 to 237 (1907).

May 1, 1911

By E. J. KENNEDY

THE 142D MEETING of the Institute is rapidly shaping up with splendid prospects of a strong technical program and the lighter side of this annual occasion amply provided for. The date is February 20 to 23. The technical sessions will be held in the Engineering Societies building; the smoker-dinner, the informal dance, and the annual reception and dinner, at the Commodore Hotel, Monday, Tuesday and Wednesday respectively. The news to date on the technical side is as follows: Mining Methods-Subsidence The Mining Methods Committee has prepared an interesting program which will be divided into two sessions to be held early in the week. At the first there will be papers on mining methods and development, including a description of the "Sinking and Equipment of No. 2 Shaft at Minas de Matahambre," by Dudley D. Homer and R. H. Cromwell. They describe in considerable detail the equipment used and the practice followed in sinking this important shaft, giving detailed costs and performance figures. Hoist¬ing ?arrangements and mining practice at the "Red Ore Mines of the Woodward Iron Co. at Bessemer, Ala.," are described by Tenny C. DeSollar, superintendent of mines, in a second paper. At this session of the Mining Methods Committee, H. M. Roche and R. E. Crockett, of the Committee on Eastern Magnetite Mining and Milling Methods, will present their paper, "Iron Ore Mining at the Scrub Oak Mine." This mine is in the highlands of New Jersey about 40 miles west of New York City. Prof. Robert K. Warner of Yale University will present a paper on "The Selection of a Mining System," which should have an interesting discussion. Pierre R. Hines, of Portland, Ore., will present, with stereopticon slides, his paper on "The Owyhee Tunnels, U. S. Reclamation Project, Owyhee, Oregon," describing one of the recent irrigation undertakings.

Jan 1, 1933

By John C. Branner

Inquiries are frequently made concerning the chalk- and clay-beds of Arkansas, usually with a view to the manufacture of Portland cement. The chalk-deposits were first described by Professor R. T. Hill in the annual report of the Geological Survey of Arkansas for 1888, vol. ii., pp. 153-162. Since the publication of that report I have visited localities then unknown, and have accumulated considerable additional information concerning these deposits, dl of which is brought together in the present paper. My report upon the clays of the State has never been published; only a few of the more conveniently available deposits are mentioned in the present paper. The Chalk-Deposits. Stratigraphic Position of the Chalk.—The chalk-deposits of Arkansas belong to rocks of Cretaceous age. The Cretaceous rocks are confined to a single definite area in Southwest Arkansas. Beginning on the Ouachita river, a little northeast of Arkadelphia, its southern or upper margin follows a line about five miles southeast of, and approximately parallel to, the St. Louis, Iron Mountain and Southern Railway from Arkadelphia

Jan 1, 1898

By AIME AIME

AWIDE variety of subjects was discussed at the Wednesday sessions on Non-metallic Minerals. W. M. Weigel as chairman, presided at the morning session, and W. M. Myers, vice-chairman, in the afternoon. In the morning session a paper by W. N. Logan on "Mineral Wool Resources of Indiana" was read by H. H. Hughes. Mr. Logan explained that as Indiana is the principal source of mineral wool, the paper might well he entitled "Mineral Wool Resources of the United States."

Jan 1, 1932

By M. D. Curran

AS applied to coal, the term processing is subject to many interpretations. To some it means preparation of coal for the market by mechanical means such as crushing, sizing, washing, or treating with oil or chemicals to eliminate dust or improve combustion quality. To others it means conversion of the coal to other commodities as in carbonization to produce coke and by- products, or to liquids by application of the hydrogenation process. I prefer to classify the various forms of mechanical treatment under the heading of beneficiation and apply the term processing to those methods of treatment that destroy the coal sub- stance through distillation or hydrogenation.

Jan 1, 1939

Aamot, Olav Crone, (M'29) Chem. Engr., Elektro¬kcmisk, Raadhusgt. 32, Oslo. Norway. . Aase. Glenn D., (J'40) Jr. Met., American Smelt. & Refin. Co., Selby, Calif. Abadie, Henry G., (J'43) Petr. Engrg., Avenal, Calif. Abadilla, Quirico A., (M'38) Min. Engr., Dir., Bureau of Mines, Manila, P. I. Abbott, Agatin Townsend, (J'40) Jr. Engr., Phelps Dodge Corp., Morenci Branch. Morenci. Ariz. Abbott, Clarence E., (M'04) Civ. Engr. V.P., Tennessee Coal Iron & R.R. Co., 1542. Brown Mars Bldg. Birmingham. Ala. Abel, Raymond L.. (M'23) Chem. Engr., Com¬manding Officer, Pittsburgh Chem. Warfare urement Dist., American Bank Bldg.. Pittsburgh. Pa. Abel, Walter D., (M'32) Min. Engr., Supvr. Engr.. R.F.C., Los Angeles, Calif. Abele, Louis T., (M'31) 423 3rd Ave., Decatur. Ga. Abell, Leo M.: (M'31) Mill Supt. & Met.. Em¬ peror Gold Min. Co., Ltd., Vatukoula. Fiji Islands. Abernathy, G. E., (M'38) Geol., Kansas State Geol. Survey, Pittsburg, Fan. Abernathy, Jack H., (M'40) Cons. Petr. Engr., First National Bldg.. Oklahoma City, Okla.

Jan 1, 1943

By Johnston, T. L.

BISMUTH is found as native metal associated with tin, copper, cobalt, silver, gold, or other metals and in a variety of ores. The more important ones are: bismuthinite (bismuth glance), Bi2S3; bismite (bismuth ochre), Bi2O3.3H2O; and bismutite (bismuth carbonate), Bi2O3CO3?H2O. Of lesser importance are the arsenate, telluride, and vanadate. The sulfide is the most common; the others are often oxidation products from this mineral. Bismuth minerals have been found in various places in the United States, principally in Colorado and Utah, but no ores are mined solely for bismuth. In the Granite mining district of Beaver County, Utah, a stratum of limestone about 6 ft. thick has been almost completely replaced by contact minerals in which bismuthinite associated with pyrite and molybdenite was found intergrown with silicate minerals. In the early days a few small lots of ore assaying 7 to 10 per cent bismuth were shipped from this district. Native bismuth has been found in the Clifton and Tintic districts of Utah. Bismuth is produced as a byproduct in the refining of lead, copper, gold and silver ores, it being recovered from the anode mud from the Betts process. Deposits of bismuth minerals exist in Argentina, Aus¬tralia, China, Japan, Germany, Spain, Peru, Bolivia, and Canada, but Bolivia is the principal, producer and could easily supply all of the present world's demand.

Jan 1, 1933

By Perry Olcott .

THE Taka oil field is in the northern part of Titus and Franklin Counties, in north- eastern Texas. The small town of Talco, from which the field derives its name, is on the P. & Mt. P. R. R., about 15 mi. north of Mt. Pleasant, the county seat of Titus County. The oil field extends east and west from the town of Talco, the approximate center. In May, 1924, R. L. Cannon, while doing surface geology for the Humble. Oil & Refining Co., mapped the surface trace of this fault structure as evidenced by Upper Midway faulted down against Lower Midway. In the interval of sixteen years between the original surface work and the recent productive well completion, approximately eight wells were drilled into the Woodbine sand without success. The structure was well defined by those tests and all of the wells en-

Jan 1, 1936

By Willard L. Cumings, Benjamin L. Miller

(Glen Summit Meeting, June, 1911.) I. THE CAMAGUEY DEPOSITS. 1. Location. THE Camaguey brown iron-ore deposit covers the top of San Felipe hill, the nearest point of which lies 14 miles NW. of the city of Camaguey. While there are several low flat-topped hills in the vicinity covered with a more or less continuous mantle of brown iron-ore, the deposit of San Felipe hill is the only one of any size and importance, and the name "San Felipe district " is proposed for the region. The deposit extends in a NW-SE. direction for a distance of about 10 miles, with an average width of 5 miles. The location is shown in Fig. 1, a sketch-map of the eastern part of Cuba. Fig. 2 is a map of the San Felipe district. 2. Description. The district is mentioned by Spencer,1 who says: "The Cubitas iron-ore fields are situated from 12 to 15 miles north of Camaguey City, in the province of Camaguey Within an area measuring roughly 10 miles east and west and 4 miles north and south, there are several flat-topped mesas rising 300 to 400 ft. above the level of an almost featureless plain which extends for many miles in all directions except toward the north." With the exception of the discrepancy in his statements as to the distance from Camaguey and the area of the hill, which is over 50 sq. miles, his description is a very good one. Kemp 2 has the following to say of ores in Carnaguey Province * Geologist, Bethlehem Steel Co. + Professor of Geology, Lehigh University. 1 Bulletin No. 540, U. S. Geological Survey, p. 324 (1908). 2 The Iron Ore Resources of the World, printed by the Eleventh International Geological Congress, vol. ii., p. 795 (1910).

Mar 1, 1911

By C. C. Hawes

SILICA is the main impurity in iron ore. It is intimately associated with the iron oxide, sometimes free but more often in the combined state, as a mineral silicate. Its separation and purification sometimes present difficult problems to the analyst. In the absence of any definite knowledge to the contrary, orthosilicic acid. H4SiO4, is supposed to be the only silicic acid made, all other forms, such as metasilicic acid, H2SiO3, representing different degrees of its dehydration. These acids are exceedingly weak but form the most stable compounds found in nature. They are known as the silicate minerals and are formed by the combination of the different metallic oxides

Jan 1, 1936

By J. R. McWilliams

Several of the current concepts of brittle fracture involve consideration of the existence of defects or flaws. Griffith 1 observed that the tensile strength of brittle materials was several orders of magnitude less than might be expected from the calculated strength of the molecular bonds. He was able to show that the stress concentration at the tip of an elliptical crack is sufficient to raise the local stress level many fold. He therefore proposed that real materials do contain such stress risers in the form of minute cracks and that this accounts for the rather large difference between theoretical and actual strengths of brittle materials. The degree of stress magnification depends to a great extent upon the orientation of the crack with respect to the general stress system, and to the general geometry of the crack.

Jan 1, 1967

By F. C. Greene

Development work in western Missouri was continuous during 1933, owing to the shallow depths at which production is obtained and the low operating costs. Unfortunately, no statistics covering the total production of oil and gas during the year are available. No new oil-producing pools were opened in 1933, but the Knoche area in 1.46 N., R.33 W., Cass County, was extended. There are probably less than 100 producing oil wells, all in Cass and Jackson counties, with a combined production of possibly around 150 bbl. daily. Several new gas areas were developed and there were several extensions of old areas, in 1933. Production was extended north by an entirely new pool—the Hammond pool, north of Plattsburg in Clinton Co. (sec. 18, T.55 N., R.31 W., and sec. 13, T.55 N., R.32 W.) where 13 wells were completed, the largest producing 2,332,000 cubic feet. In the Bartle and Marshall pool in secs. 3-4-9-10, T.47 N., R.33 W., Jackson County, four wells opened a new area. The largest well was 1,000,000 cubic feet. There were some small extensions near Independence, Jackson County. Two wells of about 300,000 cu. ft. were completed at a depth of 700 ft. in Kansas City and in a deeper sand than is usually productive. The Shaler area, in secs. 27-34, T.44 N., R.33 W. in Cass County, was extended with several wells, the largest of which was 300,000 cubic feet. The production in the pools mentioned is obtained chiefly from the Henrietta and Cherokee formations of the Pennsylvanian age.

Jan 1, 1934

By Sherwin F. Kelly

THOUGH the Geophysics Commit- tee limited itself to two sessions this year, both of them marked by a high percentage of absentee authors, even this situation failed to dampen the and or of the ebullient geophysicists, who bandied no small amount of good- humoredlv barbed discussion. Hans Lundherg offered some constructive criticism of last year's report by the Geophysics Education Commit- tee, making a plea for more training in field techniques and less insistence on rigorous theoretical training. Carl Heiland pointed out the necessity of making geophysics and geology courses more attractive in order to draw more students into these fields. Exception was taken to this line of reasoning by Father Macelwane and Sherwin F. Kelly who emphasized the necessity for sound basic training if competent geophysicists were to be turned out. This discussion developed apropos of the report of the Geophysics Education Committee, which had been postponed from the Education Division meetings, but was not read as it was available in mimeographed form. Except for this diversion the morning program fol-

Jan 1, 1944