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By John Chipman, Carl F. Floe

The system molten copper-oxygen-sulphur is of interest from both the practical and theoretical standpoints; practically, because oxygen and sulphur play an important role in the commercial production of copper, and theoretically because it offers a chance to study the reaction between an oxide gas, SO2, and a molten metal. Reactions of this type, such as that between CO or CO2 and molten iron, are important in many metallurgical operations. Again, the determination of any gas-metal equilibrium is of theoretical interest and value insofar as it contributes to the general development of the laws for solution of gases in metals. This problem is being given an increasing amount of attention in modern metallurgy. This paper is the first of a series and presents the results of a determination of the solubility of sulphur dioxide in molten copper at temperatures from 1100" to 1500ºC., and pressures from about 20 mm. of mercury to somewhat above atmospheric. Review of Previous Work The solubility of gases in most liquids has been found to obey Henry's law, which states that for a fixed temperature the amount of gas dissolved is directly proportional to the pressure. However this law does not hold for liquid metals. Instead, it appears that for many gases, particularly the simple diatomic ones such as O2, N2 and H2, the amount dissolved in liquid metals is directly proportional to the square root of the pressure. This is known as Sieverts' law. It may be recognized as a special case of Henry's law, which applies when the solute gas is dissociated into atoms or when it reacts with the solvent metal to form solute molecules containing single atoms of the gaseous elements, as, for example: 2M+G2=2MG K=(MG)2 /M2 X PG2 [I] which, if the solubility is not too high and the concentration of metal therefore nearly constant, can be simplified to: MG = K1 vPG2 [2 Following the same reasoning, it would be expected that the solubility of SO2 in copper would be proportional to the cube root of the pressure, the reaction being as follows: 6Cu + SO2 = Cu2S + 2Cu2O [3] K= Cu2S X (Cu2O)2 i - (Cu)6(Pso2) [4] or, neglecting the change in metal concentration and considering that the concentrations of sulphur and oxygen are both proportional to the volume V of gas absorbed: K1 =V3SO2 /Pso2 or

Jan 1, 1941

By Carl F. Floe, John Chipman

The system molten copper-oxygen-sulphur is of interest from both the practical and theoretical standpoints; practically, because oxygen and sulphur play an important role in the commercial production of copper, and theoretically because it offers a chance to study the reaction between an oxide gas, SO2, and a molten metal. Reactions of this type, such as that between CO or CO2 and molten iron, are important in many metallurgical operations. Again, the determination of any gas-metal equilibrium is of theoretical interest and value insofar as it contributes to the general development of the laws for solution of gases in metals. This problem is being given an increasing amount of attention in modern metallurgy. This paper is the first of a series and presents the results of a determination of the solubility of sulphur dioxide in molten copper at temperatures from 1100" to 1500ºC., and pressures from about 20 mm. of mercury to somewhat above atmospheric. Review of Previous Work The solubility of gases in most liquids has been found to obey Henry's law, which states that for a fixed temperature the amount of gas dissolved is directly proportional to the pressure. However this law does not hold for liquid metals. Instead, it appears that for many gases, particularly the simple diatomic ones such as O2, N2 and H2, the amount dissolved in liquid metals is directly proportional to the square root of the pressure. This is known as Sieverts' law. It may be recognized as a special case of Henry's law, which applies when the solute gas is dissociated into atoms or when it reacts with the solvent metal to form solute molecules containing single atoms of the gaseous elements, as, for example: 2M+G2=2MG K=(MG)2 /M2 X PG2 [I] which, if the solubility is not too high and the concentration of metal therefore nearly constant, can be simplified to: MG = K1 vPG2 [2 Following the same reasoning, it would be expected that the solubility of SO2 in copper would be proportional to the cube root of the pressure, the reaction being as follows: 6Cu + SO2 = Cu2S + 2Cu2O [3] K= Cu2S X (Cu2O)2 i - (Cu)6(Pso2) [4] or, neglecting the change in metal concentration and considering that the concentrations of sulphur and oxygen are both proportional to the volume V of gas absorbed: K1 =V3SO2 /Pso2 or

Jan 1, 1941

By S. H. Ash

With statistics still incomplete, it appears that the safety record of the mineral industry for 1955 will do well to hold its own in comparison with 1954. On the one hand, metal mining shows an improvement in its record, due in part to intensive campaigns for preventing ground fall accidents. Coal mining, on the other hand, is showing a poorer record in 1955 than for the preceding year. While no major disasters occurred during the year, increased fatalities resulted from ground fall, haulage, and machinery accidents. It seems probable that increased job training may serve to improve the situation. Health: Utilization of diesel equipment continues to increase in noncoal mines, in spite of existing prejudice. In 1955 two types of diesel-driven tractors and one shuttle car were approved by the USBM. Where diesel engines are used controlled ventilation is mandatory in order to keep the CO content under 20 ppm, but such ventilation is not difficult to achieve with normal equipment.

Feb 1, 1956

By Lyndon L. Foley

The proper spacing of oil wells is a problem of vital importance to the oil industry. Conservation demands a maximum recovery, while economic considerations attach primary importance to profitable extraction of oil. Formulas have been evolved,1-4 which attempt to solve the spacing problem mathematically, using reservoir characteristics as factors. Comparisons have been made of fields producing from supposedly similar sands, which have been drilled to varying densitiesl5,6 and also of different leases in the same field. 5-8 Intermediate wells have been drilled in old, depleted fields to test the efficiency of drainage by the original operation.9-11 Intermediate wells have been drilled also to obtain cores of the depleted sand for analysis, from which to learn the degree of efficiency of extraction. The problem is being attacked by many students, and along several different lines. Unfortunately, the fields now depleted were produced generally without restriction, and conclusions drawn from them may not apply to fields operated under restricted production. Reservoir conditions in a restricted field, especially reservoir pressures and pressure gradients within the reservoir, are quite different from those in a field produced to capacity. Many people have held the idea that the closer the spacing, the greater the recovery. This general statement is not always true, as other factors than well spacing enter into the recovery problem. Cutler,5 who has been quoted frequently by advocates of close spacing, limited his conclusions to gas-drive fields, and to the particular fields and spac-ings that he investigated. Hill and Sutton7 analyzed four tracts in the Powell field; the tract most closely drilled had the third largest recovery per acre-foot, and the tract with the widest spacing had the second largest recovery per acre-foot. A search of the references to well spacing in the publications of the U. S. Bureau of Mines5,13-19 discloses repeated condemnations of the wastefulness of the practice of town-lot drilling.

Jan 1, 1938

By B. Fazan, O. D. Sherby, J. E. Dorn

McLean's technique was employed to determine the effect of temperature on the contribution of grain boundary shearing to the total creep strain in pure aluminum over the range of 610° to 747°K. The contribution of grain boundary shearing at the same stress was found to depend upon a temperature-compensated time, where the activation energy AH was practically identical with that for total high temperature creep. SEVERAL outstanding investigations by McLeanl-' have demonstrated that the total creep strain in polycrystalline aluminum at 473°K arises from microscopically detectable slip, subgrain tilting, and grain boundary shearing. Whereas microscopically detectable slip arises from dislocations that move out of the grains, subgrain tilting is due to entrapment of dislocations of like sign in subgrain bound-arles. Consequently, creep in polycrystalline aggregates appears to be the resultant of two mechanisms, namely, migration of dislocations and grain boundary shearing. This suggests that an appropriate law for creep should contain two additive terms ?1 = ?d + ?yb where the total creep strain, ?1, depends on the sums of the creep strains arising from motion of dislocations, ?d, and from grain boundary shearing, ?yb. But extensive investigations5 over wide ranges of alloys, grain sizes, temperatures, and stresses have shown that the total creep strain is quite accurately dependent on the single term functional relationship ?1 = f (?), s = constant where s is the stress (constant),* ? = te-?H/RT, t is the time under stress, AH is the activation energy, R is gas constant, and T is absolute temperature. Since Eq. 2 was found to be valid over those ranges where appreciable grain boundary shearing is observed, it appears probable that the activation energy for grain boundary shearing might be identical with the activation energy for migration of dislocations. Thus, under a given stress, it could be thought that where fd and fgb represent the appropriate functions for each mechanism of creep. The primary objective of this investigation was to obtain a direct check on the accuracy of this hypothesis. Experimental Procedure and Results Rolled aluminum sheet (99.987 pct Al), 0.100 in. thick, was used in this investigation. Creep specimens having a 0.25 in. wide, 3 in. long gage section were so machined that their axes were in the rolling direction. All specimens were annealed for 9 hr at 894°K before testing to produce a mean grain diameter of about 0.1 in. One face of each specimen was polished electrolytically in 10 pct HBF4. In order to permit accurate measurements of grain boundary shearing, the polished surface was lightly scribed with a ruling machine accurate to ±0.0001 in. to give a uniform grid of lines which were 0.01 in. apart. Although it was thought that surface working might modify the creep behavior in the vicinity of the scribed grid lines, this technique nonetheless was employed because such local differences in creep properties should not modify seriously the fractions of the total creep strain due to grain boundary shearing or to migration of dislocations. All creep tests were conducted under constant load with an initial stress of 250 psi. The specimen tem-

Jan 1, 1955

By R. S. Shoemaker, F. W. McQuiston

EMPEROR GOLD MINES Vatukoula, Fiji 1974 Operating Data to July 1 ORE DESCRIPTION: Ore bodies occur in basalt and associated ash beds overlain by andesite tuffs and sediments. The basalt in much of the ore mined is weathered with alteration of olivine to serpentine and iron oxides, and augite to chorite. The most important host minerals for gold are the tellurides sylvanite and hessite. Next in importance the sulphide s, pyrite, marcasite and arseno-pyrite. A small amount of free gold also occurs. Chalcopyrite, sphalerite, tetrahedrite, bornite, galena and native tellurium are present in small quantities. TYPE OF MINE: Underground and open pit ORE HAULAGE TO MILL: 3.5 ton bottom dump skips from underground. 7 ton trucks from open pit. CAPACITY IN TONS/24 HRS: 1345 short tons ASSAY HEADS (1973): 0.232 oz Au per ton, 0.357 oz Te per ton PRODUCTS: Gold Bullion (400 oz bars) Metallic Tellurium (1 2 lb bars ) RECOVERIES: AU 86.2% Te 88.0% ORE GRINDABILITY: 9.25 Kwh/T TOTAL POWER: 25.7 Kwh/T WATER: Pumped 112 mile to a 318, 000 gallon head tank. Consumption: 2 140 gal per ton, no reclaimed water used. TAILINGS: Pumped 2 /3 mile through 8" pipe. Uphill sections are steel. Downhill sections are fibro asbestos.

Jan 1, 1975

By Sidney A. Swensrud

This paper reviews the subject of gasoline margins, discusses some of the more current marketing problems, and gives some consideration to the main urges to marketing expansion, or overexpansion, in the oil industry. Margins In an earlier paper1, some comparisons were shown for the years 1929, 1930 and 1931, of the margin between the refinery cost of gasoline in Oklahoma, the market price in Oklahoma, and the average retail price in 50 representative cities of the United States. These figures indicated a small margin for the refiner in 1929 between his gasoline cost and the wholesale price, which, however, had turned into a loss by 1931. The margin between either refinery costs or wholesale prices and the retail price in the 50 cities showed a continuous decline during the three years. We have now worked out these figures on a similar basis for a longer period—from 1928 through 1936. The figures for refinery gasoline cost are slightly different from those in the earlier study, owing to the use of

Jan 1, 1937

By AIME

BORN in 1899, in Bridgeport, Conn., E. A. Anderson grew up in a center of the nonferrous metal industry. Perhaps that had something to do with his selection of mining as a career while an undergraduate in Yale. After securing his Ph.B. in mining he worked for a year at Handy & Harman. By this time physical metallurgy had supplanted his interest in mining and he entered the Yale graduate school where he secured his M.S. degree in metallography under C. H. Mathewson. After completing his graduate work he entered the employ of The New Jersey Zinc Co. in their research division where he has remained ever since. The transition from graduate study to industry involved no disruption of technical interests. Academic research relating to the zinc-aluminum alloys, then coming into use for die-casting, was followed by extensive and productive industrial research in the perfection and commercialization of these alloys. Research on rolled zinc and rolled zinc alloys, corrosion and stress corrosion, dry cells, electroplating on zinc, and electrodeposition of zinc followed in overlapping succession as time passed.

Jan 1, 1947

NEW MEMBERS. The following list comprises the names of those persons who became members during the month of April, 1913: BARNES, BLAKESLEE, Min. Engr Burrwood, La. BOYLSTON, HERBERT M., Cons. Met. Engr 26 Abbot Bldg., Cambridge, Mass. BUEHLER, HENRY A., State Geol Rolla, Mo. CASTO, WILLIAM H., JR., Mining Bonanza, Idaho. COHEN, MAXWELL B., Mill Operator Miami, Ariz. EVANS, MILTON R., Shop Draftsman 92 Division St., Kingston, Pa. HARPER, WALTER S., Asst. Treas 42 Broadway, New York, N. Y. JAMES. JAMES S.. Min. Engr Telluride. Colo.

Jan 5, 1913

Abbott, Franklin E. Adgate, Frank Aertsen, G. Aid, Kenneth Albert, H. I. Alexander, D. B. W. Allan, Wm. G. Allen, R. 0. Allen, Roy H. Aller, Mr. and Mrs. F. D. Altmayer, Maurice Ambler, Harry A. Ambrose, A. WV. Ammon, Mark A. Ammon, Mr. and Mrs. Robt. Anderson, George H. Anderson, Mr. and Mrs. L. D. Andros, S. 0. Appleby, W. R. Archer, R. S. Armitage, Paul Arobb, Alden D. Arthur, Walter Ashman, A. 0. Atkinson, R. H. Aupperle, J. A. Austin, D. F. Avery, G. E.

Jan 11, 1919

On the following pages are abstracts of papers published by the Institute during the year 1936 as TECHNICAL PUBLICATIONS and CONTRIBUTIONS, papers in bound volumes appearing for the first time, and papers in MINING AND METALLURGY For abstracts of papers that appeared in bound volumes in 1936 but that were published as TECHNICAL PUBLICATIONS in 1935, see the YEAR BOOK dated January 1936.

Jan 1, 1937

THE morning session on non-metallic minerals was opened briefly by the chairman, Oliver Bowles, giving the usual instructions and then turning immediately to the introduction of the speakers. "Min-ing and Preparation of the St. Peter Sandstone in' Arkansas" by D. D. Dunkin was first presented by W. M. Weigel, mining technologist for the Missouri Pacific R. R. The paper covered a discussion of the geology of the sandstone, correlating it with the sand-stones at Klondike, Mo., and at Ottawa, III. Its physical appearance, structural characteristics and thickness; the mining methods, blasting, loading, haulage and classification were taken up. A series of slides aided in clarifying the details. The discussion consisted of questioning Mr. Weigel on operating details. The second paper, "Geology and Mining of Diaspore and Flint Fire-Clays of Missouri," written by H. S. McQueen, geologist with the Missouri Bureau of Geology and Mines, and C. R. Forbes, professor of mining, Missouri School of Mines and Metallurgy, was presented by Mr. Forbes. It thoroughly covered the geology, stressing the peculiar sink formations in which all diaspore clay deposits of the region occur. The crudeness of the mining methods was mentioned and believed justifiable because of the small size of the indi-vidual deposits. It was stated that the diaspore and flint clay deposits of Missouri were confined to an area 60 mi. square and it was found in a survey that the average deposit had dimensions comparable to the fol-lowing: 100 ft. long, 75 ft. wide and 50 ft. deep. The largest deposit found was 800 ft. long. 500 ft. wide and 20 ft. deep. It is estimated that the known reserve of clays is from 750.000 to 1,500,000 tons. Mr. Forbes stressed the fact that in mining clays the major problem is entirely one of sorting. This is done under the supervision of a pit foreman trained to make this classification by eye. The mine-run clays are sepa-rated into diaspore clay ranging in alumina content from 70 to about 85 per cent, first grade Burly clay 00 to 70 per cent, and Flint clay 52 to 60 per cent. Discussion of the paper consisted in questioning Pro-fessor Forbes on labor. cost, haulage, drilling, and geology.

Jan 3, 1928

By R. Haynes

ON the basis of compositional changes of a phase observed in a eutectoid Cu-Al alloy1 it has been suggested that mechanisms for the decomposition of the ß phase proposed by earlier workers2-5 were incorrect. These data are reinterpreted in conjunction with lattice parameter data obtained on an alloy containing 12.2 pet Al, whose isothermal transformations have been reported elsewhere.5 The a Lattice Parameters of a 12.2 Pet A1-Cu Alloy—~iffraction patterns of completely transformed specimens were obtained in a back reflection camera using copper Ka radiation. Lattice parameters of

Jan 1, 1959

By Irving B. Cadoff, Stojan M. Zalar

AgInTe2, CuInTe2, and all Proportions of CuxAg1-xInTe, forMed homogeneous single phase alloys after direct solidification from the nielt. X-ray analysis indicated a zinc-blel~de strzccture typical of the chalcopyrite compounds, and the electrical resistivity and Sccbeck coefficient values were in the semiconducting range. AuInTe, and AuxA4g,-, InTe, formed by what appeared to be a peritectic reaction (the thermal analysis curves showing more than one arrest) and were conseyue~ztly polyphase. Substitution of copper into AgIrzTe, resulted in a continuous transition in the room tenzperature Seebeck coefficient from the negative AgIzTe, to the positive CuInTe,. A zero coefficient was obtained at about Cuo.55 Ago.45 InTe, . The temperatzire variation was similar to that observed for the stoichiometric compounds, that zs, tendency towards "p" concEuction at elevated temperatures. The thernzoelectric figure of merit for the compo~uzds, as determined by the Putley -Harmnn method were in the range 10- to 10-7 "K-l; the thermal conductivities in the order of 0.15 cal per sec-cm-oK. INCREASED interest in semiconducting intermetallic substances is expanding much of recent research from simple binary compounds into polyatomic systems and solid solutions. Ternary compounds A' represent a covalent extension of the binary semiconductors Within the a tin isoelec-tronic series, Ag-Cd-In-Sn-Sb-Te-I, divalent cadmium atoms in CdTe are being substituted for by monovalent silver and trivalent indium atoms to form the compound AgInTe, . By cross-substitution with elements of other isoelectronic series, a great number of ternary compounds A 'B"'c? is possible. In all of them, however, a necessary though not sufficient condition for the covalent, semiconducting bond—that there be four sharing orbital electrons per atom—must be fulfilled. In AgInTe,, each silver or indium atom is tetrahedrally surrounded by four tellurium atoms, while each tellurium atom is co-valently bound to two silver and two indium atoms. Synthetic chalcopyrites A'B"'c~ were first recognized as potential semiconduct&rs by Goodman and Douglas.' Austin, Goodman, and Pengelly discuss preparation difficulties and some electronic measurements on AgInS, , AgInSe, CuInSe, , AgInTe, , and CuInTe,. Chalcopyrites A B c2v are mentioned in papers attempting to classify and predict semiconducting behavior of intermetallic compounds; on the basis of saturated tetrahedral sp3 bonds,3 by specific selection criteria,' and by crystallographic considerations."

Jan 1, 1962

By E. P. Jennings

These unique copper-deposits occur on the top of the Kaibab Plateau, in Cocouino county, Arizona, and extend from the northern edge of the Grand Cañon of the Colorado river to near the Utah State line. The best-developed deposits are near Jacobs Lake, 30 miles south of the Utah line, where they are 16 ft. thick, of unknown width, and are more or less continuous for 5 miles. From Jacobs Lake to the edge of the Grand Cañon, a distance of 40 miles, outcrops of ore have been found, but no explorations have been made except those of wandering cowboys and hunters. The Kaibab Plateau, the highest of the Colorado river plateaus, is a great uplift, about 90 miles long from north to south, and from 10 to 20 miles wide from east to west. Its southern face is the Grand Cañon; its western boundary a N—S. fault plane, which separates it from the Eanab Plateau, lying 1,500 ft. below. Its eastern edge is a monocline which brings the horizontal beds of the high plateau to the level of the plateaucountry of eastern Utah. The elevation of the plateau near the Colorado river is over 8,000 ft., and about 6,000 ft. at the Utah line. Its structure, as shown by the western fault, consists of about 500 ft. of Aubrey limestones underlain by 1,000 ft. of red sandstones. The limestone is the upper member of the Carboniferous, and is overlaid by the marls and shales of the Permian, 25 miles to the north on the Kanab Plateau. At the town of Kanab, near the Utah line, the Permian strata pass under the magnificent redsandstone cliffs of the Triassic, that rise to heights of 1,000 ft. above the desert. The Grand Cañon exposes a section a mile deep at the southern end of the plateau, showing all the formations from the Archean to the top of the Carboniferous.

Jan 1, 1904

By T. W. Harris

This paper was written in conjunction with the work being undertaken by the Technical Committees on Classification of Coal, and an effort has been made to compile information relative to the use of coal for stationary steam generation in order to use this information to assist the Committee on Classification of Coal for the ultimate purpose of elimination of losses both by the reduction of individual effort and waste in the consumption of material. Under the auspices of the National Association of Purchasing Agents, a questionnaire was drawn up to develop this information from stationary steam plants throughout the United States in order to consolidate the information developed from the many hundreds of boiler tests on coals consumed by various coal-burning equipment. These questionnaires covered: 1. The company reporting, location and method of delivery to the plant. 2. Complete coal data, including description of coals used (with sufficient space to include first, second and third preference) on source of coal used, complete analysis and factors affecting choice of coal used. 3. Plant data, divided into: (a,) hand-fired, (b) overfeed stokers, (c) underfeed stokers, (d) traveling grate stokers, (e) pulverized coal; and included complete description of furnace data, draft data, coal-burning rate, type of stoker, type of pulverizer, efficiency data and remarks. The questionnaire was drawn up by consultation with various combllstion engineers, including B. J. Cross, Test Engineer of the Combustion Engineering Co., W. H. Fulweiler, of the United Gas Improvement Co. and the U. S. Bureau of Mines. In all, 11,538 copies of the questionnaire have been distributed, of which 4369 were sent in duplicate. Our estimate of the total volume of bituminous coal consumed in stationary steam boilers over the 12 months of 1930 is approximately

Jan 1, 1934

By H. D. Dahl, P. C. Thakur

This paper presents an analysis of a new tool for improved productivity in coal mining: the horizontal drilling system developed by Conoco/Consol. The analysis includes a brief description of the system; discussion of the three categories of advance exploration application of horizontal boreholes; and a survey of other special mining methods planned around long horizontal boreholes.

Jan 1, 1983

By H. W. Hitzrot

*Original Pages Missing From Book

Jan 5, 1954

By Sylvan Z. Beer

Aluminum phosphide was synthesized and grown in solution of excess aluminum using a modified two-temperature technique. An inversion in the density difference between ALP and molten aluminum takes place at about 1100°. Dispersed nuclei can act as sources for further crystal growth in a manner resembling ripening. Advantage was taken of this phenomenon by introducing a stirring motion into the molten liquid. This was done with a split-phase 10-kH2 rotating magnetic field produced by four horizontal coils placed symmetrically about the furnace at the level of the molten metal. The method also prevents the formation of a surface film which would impede the reaction. By this technique vastly improved yields were obtained and flat crystals 5 by 5 by 0.5 mm were grown at lower temperatures and at greater rates than heretofore. THE family of III-V intermetallic compounds has received much attention since the prediction of their semiconducting properties in the early 1950s. Of the family, A1P has perhaps the highest band gap of those compounds normally possessing the zinc-blende structure. But it has been least studied because it is difficult to handle and grow. The handling difficulties have been dealt with elsewhere and it is sufficient to say here that, by various techniques, many of the difficulties can be overcome.' The difficulties encountered in crystal growth can be related to the refractory nature of A1P and in turn to its high band gap. Because of the anticipated high melting point of the material and the accompanying high phosphorus vapor pressure, the reported work on synthesis and growth was done by epitaxial synthesis-growth via chlorine2 and iodine3 transport and from solution of excess aluminum by the two-temperature technique.4'5 The transport-grown crystals take on the dimensions of the substrate but do not grow easily in thickness. In the usual two-temperature technique as applied on the synthesis of Alp, the temperature of the molten aluminum is kept at 1000° to 1250°C while the phosphorus is maintained at 1 to 20 atm. A thin film of aluminum phosphide and oxide form immediately, impeding the reaction and affecting the yield. Attempts to grow the Alp from such solutions by the methods used to grow Gap and InP from excess gallium and indium have not been successful. As discussed in the preceding paper,5 the yield can be greatly increased

Jan 1, 1969

By Roscoe C. Clark

A study of the effect of various corrosive waters on five different types of cements indicated that those cements containing less than 5 per cent tricalcium aluminate were the most resistant to corrosion. INTRODUCTION Oil field experience indicates that some formation waters are excessively corrosive to some cements. A study has been made to determine the most corrosive waters and the relative resistance of various types of cement to these corrosive waters. PROCEDURE This study of the corrosion of cement was limited to an evaluation of the effect of various corrosive waters on five different types of cements. A determination was made of the types of cements which offer the greatest resistance to corrosion and of the chemical contents of waters found to be the most destructive to cements. The laboratory tests were conducted by immersing small cylinders of 20 samples of set cement in various corrosive waters. The initial mixing of most of the cement slurries was done using Tulsa tap water as the mixing water; however, a few of the slurries were mixed using a sulfate water as the mixing water. When the 20 samples had been immersed for a period of nine months, they were removed from their corrosive baths, inspected and photographed. The field tests were conducted by placing ten cement specimens, each contained in a screen wire thimble, in the gas anchors of insert pumps in wells in six different fields. The specimens were observed whenever it was necessary to pull the pumps and were returned to the 1aboratory when deterioration had reached a serious state. EXPERIMENTAL RESULTS In both the field and laboratory tests the resistance of the different cements to corrosion was determined by the condition of the samples and the number of samples of each that were in good condition at the end of the immersion period. Table I lists the various cements tested in the order of their resistance to corrosion with the most resistant at the top and the least resistance at the bottom. An analysis of Table I reveals that the upper half of the table predominates in slow set and sulphate resisting cement.: (low 3CAO.A12O3 content) while in the lower half the port-land and high early strength cements are in the majority. Of the last two the high early strength cements appear to offer less resistance to sulfate water corrosion. An investigation of the composition of the cements listed in Table I indicated that as a general rule the cements containing less than five per cent tricalcium aluminate will exhibit the greatest resistance to corrosion. The destructive action of various corrosive waters was compared by listing the waters in the order of those containing the largest number of samples that failed completely. These ratings are presented in Table II with the most corrosive waters listed first and the least corrosive last. Figs. 1 and 2 show the end views of cement samples which had been immersed in the baths of five per cent MgSO, water and the five per cent Na2SO4 water respectively in the laboratory. These .pictures are representative of the results obtained and present a pictorial evaluation of the corrosive resistance of various types of cements.

Jan 1, 1950