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By James A. Todd

Use of AN-FO in underground operations has greatly reduced the cost of primary explosives. AN-FO is also less sensitive than conventional dynamites, and when properly used, is safer. Maximum safety in the use of AN-FO, however, requires an understanding of potential hazards from toxic fumes as well as static electricity developed in pneumatic loading. Safe limits and guides have been established to permit most operations to pneumatically load holes that are bottom primed with electric blasting caps, but the toxic fume hazard is less widely understood. During 1959-1960 Du Pont cooperated with the U.S. Bureau of Mines to study the toxic fumes produced by prilled ammonium nitrate-NO. 2 fuel oil mixtures. The conclusions from this work were that oxygen balanced AN-FO, when thoroughly mixed, well primed and well confined in dry holes, produces no greater amounts of toxic fumes than conventional dynamites rated Class I by the Institute of Makers of Explosives. The study also showed, however, that any deviation from these guides tends to increase significantly the quantity of toxic fumes produced. This work was reported by the Bureau of International Symposium on Mining Research at Rolla, Mo., in February 1961.'

Jan 4, 1963

By Horace Winchell

AN EXAMINATION of the Pachuca and El Oro. districts in July, 1920, although cursory and incomplete, disclosed facts of more than passing interest to the student of ore deposits; and inasmuch as the literature on these districts is limited and some of their features are little understood, a brief account may prove valuable as reconnaissance observations to be amplified by more thorough and competent observers in the future. Where no complete monograph of important mining camps has been published a partial presentation of the data is often useful, as it sometimes leads to fuller and more accurate descriptions, by stimulating discussion. The following notes are presented with the consent of Mr. A. F. Main, managing director of the El Oro Mining and Railway Co., whose fund of information and wide acquaintance with both districts alone made it possible to cover so much ground in a short time. I have also to acknowledge gratefully the aid of Messrs. C. A. Lantz and D: S. Calland of the Santa Gertrudis and Real del Monte companies, respectively, in connection with permission to inspect geological features of interest in their mines.

Jan 6, 1921

By Hallan N. Marsh

The subject of this paper is apt to bring to mind wells ranging from 6000 to over 8000 ft. in depth. However, it is uncommon to pump wells at depths greater than about 5000 ft. Fig. 1 shows the number of wells being pumped at various depths by one company in Southern California. A few companies have a very few wells pumping at depths greater than this. This paper will deal with wells between 3000 and 5500 ft. in depth. Most California oils at these depths are between 25" and 35" gravity. The subject is so broad that it will be necessary to omit many interesting phases, and to treat others very briefly. Power, power transmission equipment, power efficiency, counterbalancing, sucker rods, pumps and volumetric efficiency will be discussed. Power As a source of power, the 50/20-hp. electric motor is generally preferred. Input is generally between 10 and 25 hp. Due to the uneven-ness of the load, an input of 20 hp. on the low range is generally about all that these motors will carry without overheating, in spite of their overload capacity. In some cases the capacity of the motor limits the speed

Jan 1, 1929

By L. W. Saperstein, W. W. Kaufman

Stimulated by the hearing protection clauses in the 1969 Coal Mine Health and Safety Law, attempts were made to determine what safety hazards, in terms of warning signal discrimination, are attendant upon the wearing of hearing protectors. Warning signals of dangerous roof conditions were collected and analyzed from 11 different coal mines in four different coal seams. Primarily, signals of audible level emanating from roof, floor, or coal were recorded. The interpretations of these signals were seen to be very dependent upon coincident visual and tactile signals. Acoustic character of such signals is shown to be dependent upon the spectral energy distribution of the pulses. Roof talk signals generally have broad-band spectra concentrated below 5 kHz. Reverberation times of acoustic pulses are generally less than 0.5 sec in duration. Indications have developed which link the coal mine entry dimensions with the nature of noises recorded there. Related experiments suggest that roof talk can be discriminated from background noise equally well when wearing protection as when not. This conclusion is only appropriate when noise levels warrant the wearing of protection. When quiet, the wearing of protection somewhat reduces discriminatory ability.

Jan 1, 1976

By B. R. Palmer, M. C. Fuerstenau

Oxide and silicates respond to flotation with a large number of anionic collectors. These include carboxylates (fatty acids), sulfonates, alkyl sulfates, and certain chelating agents. In contrast to sulfide mineral flotation, relatively long-chained collectors (generally longer than 10 carbons) are required to effect flotation of this group of minerals. The structural formulas of these various anionic collectors are presented in Table 1. Formulas and solubilities of various fatty acids are presented in Table 2. These solubilities are those of the dissolved and undissociated species of the acid, e.g. oleic acid, HOl(aq). Of the compounds listed, oleic acid and abietic acid, which IS a major constituent of talloel, are used most commonly in commercial applications. The usage of these two collectors is related to cost and effectiveness. In addition to their high molecular weights, oleic acid contains a double bond in its hydrocarbon chain, while abietic acid is comprised of aromatic rings containing double bonds. The presence of double bonds increases solubility significantly over that of saturated homologues. Stability of metal-collectors assumes a most significant role in these systems, and the solubility products of various metal carboxylates and sulfonates are listed in Tables 3, 4 and 5. In addition to these properties, strength of the acids of these various anionic collectors is also important. The carboxylic and hydroxamic acids are weak acids whereas sulfonic and alkyl sulfuric acids are strong acids. All of the carboxylic acids fall in the range of pK = 4.7 ± 0.5 ([2]); the pK of hydroxamic acid is around 9 ([3]); and the pK of sulfonic acid is about 1.5 ([4]).

Jan 1, 1976

By John T. Galey

Oil and gas development in southern Pennsylvania during 1937 was marked by considerably increased activity in deep-sand drilling. Nine tests were completed to the Oriskany sand: one in Independence and three in South Beaver townships, Beaver County; one in Franklin township, Butler County, two in Slippery Rock township, Lawrence County; one in Mt. Pleasant township, Washington County, which is drilling below the Oriskany, and one in Fairfield township, Westmoreland County. Two of these wells, both of which were in the Blackhawk pool, South Beaver township, Beaver County, obtained wet gas with open-flow volumes of 1.5 million cu. ft. and 3.1 million cu. ft. and closed-in pressures of 1900 Ib. The remaining seven were unproductive in the Oriskany. Two wells, one in Hampton township, Allegheny County, which is shut down temporarily as a result of a gas pocket, and one in South Beaver township, Beaver County, are drilling to the Oriskany. One deep test on the Chestnut Ridge anticline, South Union township, Fayette County, was completed after considerable difficulty as a dry gas well in the Onondaga limestone. At this locality the cherty limestone is porous as a result of fracturing. Three additional tests are under way in the area, one in South Union township, a second in North Union township, and a third in Wharton township. Completions Oil.—Despite price cuts and production curtailment of Pennsylvania Grade crude, caused largely by a decreasing demand from export markets, operation in the shallow oil areas continued at a fairly high rate and a number of good wells were completed. Some of these were new wells in close proximity to old production and others were old wells drilled into deeper pays. One new well of a number of producers drilled to the Nineveh Thirty-foot sand in the Harvey pool, Center township, Green County, made 400 bbl. of oil and 500 million cu ft. of gas the first 24 hr. The Chambers dam pool of Amwell and South Franklin townships, Washington County, yielded a number of Fifth Sand producers with initials as high as 200 bbl. Several wells in the old Mars-Butler field

Jan 1, 1938

AT the session on mine ventilation on Oct. 8, 1926, held in connection with the. autumn Institute meeting at Pittsburgh, there was considerable dis-cussion of the use of auxiliary fans in coal-mine ven-tilation, and before adjourning the following resolu-tion was passed: "Resolved, that we, as a Committee, in consideration of the increasing and widespread use of auxiliary fans iii coal mines deplore the fact that they are often used without adequate knowledge of their limitations and dangers."

Jan 2, 1927

Reading Anthracite, like AIME, is celebrating its 100th anniversary. While Reading marks a century in the mining, preparation and marketing of domestic anthracite, AIME commemorates 100 years of parallel endeavor in promoting the economical production of minerals and metals and the welfare of those employed in the industries dedicated to this pursuit. Both Reading and AIME possess another common denominator, in that both were conceived in the eastern anthracite fields of Pennsylvania, where coal reigned supreme in the early days of mining.

Jan 1, 1971

Consolidation Coal Co. is solving the abrasion problem and cutting maintenance costs at its Georgetown preparation plant by using ceramic alumina tiles from The Carborundum Co. The Georgetown complex handles the output of four deep mines and three strip mines in the Cadiz, Ohio, area-washing about 73 000 tons (80,000 st) weekly. Plant superintendent Duke Zinko is using wear-resistant Dura-frax® tiles in several applications, replacing wear plates, profile rubber, and other materials he has tried over the years.

Jan 7, 1979

By R. T. Hukki

BALL wear as observed in grinding installations is the combined result of mechanical wear and corrosion. Corrosion should be a linear function of the ball surface available. Ball corrosion, however, has been studied so little that its effect, although of great importance, cannot be included in the analyses given here. In a separate paper' it is shown that [ ] Exponent m is the slope of a straight line on logarithmic paper relating mill speed (on the abscissa) and mill capacity (on the ordinate).

Jan 6, 1954

By R. Walker, R. J. Anslow

Today at Tampa we see the end results of a team effort: A vital link in an intermodal transportation system, the link that enables the unit-train concept to be employed with full effectiveness and the link that improves the economics of water transportation systems. Two new phosphate transfer complexes with a multi- million ton annual capacity are in operation in Tampa, Fla. Revolutionary in concept, these companion installations represent a total investment in the Tampa Bay area of $18.5 million.

Jan 1, 1970

By Cleland N. Conwell

Reclaiming mined land in northern regions is less difficult than reclaiming semiarid lands. In 1972, the Usibelli coal mine near Healy, Alaska, initiated experimental plots to determine the proper grasses and amounts of fertilizer. The following spring, approximately 1600 acres of land disturbed by mining were seeded by low-flying aircraft. The reclamation project was evaluated by the State of Alaska and has been adjudged successful. The information gained is being used in reviewing prospecting permits and granting coal leases on state lands.

Jan 1, 1977

By Lauren A. Wright

The principal talc deposits in California are in a 200-mile belt paralleling the state's eastern border. The southernmost deposits represent selective alteration of early pre-Cambrian (?) carbonate strata, and are associated with granitic rocks. Deposits in the Death Valley area are at or near contacts between late pre-Cambrian carbonate rocks and diabase sills. Those in the Inyo Range area are chiefly alterations of Paleozoic carbonate rocks and silica rocks. Most of the state's talc output is used in ceramics.

Jan 1, 1950

By J. C. Fisher

THE following facts are reasonably well established concerning the influence of boron on the hardenability of steel:1-4 1—Boron does not appreciably influence the ther-

Jan 1, 1955

By H. E. Mussey

When the American Institute of Mining Engineers visited the Birmingham district in May, 1888, the four Ensley furnaces (Fig. 1) then completed were referred to as monumental.' Their dimensions are givcn in Table 1. Mr. Gordon stated, with considerable satisfaction, that on the preceding day one furnace had produced 165 tons. The blast was

Jan 1, 1925

The first session of the Institute was held at the Smithsonian Institution, on Tuesday evening, February 22d. The members were welcomed to Washington and to the Smithsonian by Prof. Joseph Henry. President Holley responded to the cordial welcome of Professor Henry, and then read an introductory address on the subject of Technical Education. Following the discussion on President Holley's address the following persons, duly proposed and indorsed by the Council, were elected members and associates of the Institute : MEMBERS. Emile R. Abadie,. .. .. St. Louis, Mo. R. J. Anderson,.....Pittsburgh, Pa. Commander L. A. Beardslee,. .. Washington, D. O, Charles Bender,. .. .. New York City. Charming M. Bolton,. .. . Richmond, Va. Thomas E. Bowman,. .. . Silverton, Colorado. Calvin E. Brodhead,. .. . Bethlehem, Pa. M. L. Brosius,. .. .. . Lewistown, Pa. Harvey H. Brown,. .. .. Cleveland, Ohio. James A. Burden,.. .. . Troy, N. Y. J. P. Clemes,. .. .. . Sonora, Mexico. N. H. Cone,. .. .. . Nederland, Colorado. W. F. Durfee,.. .. . New York City. Robert Frazer, Jr.,. .. . Ashland, Pa, Joseph E. Galigher,.. .. . Bingham, Utah. William Golding,.. .. . Steel Works P. O, Pa. Samuel E. Griscom,.. .. . Pottsville, Pa. Gen. E. Burd Grubb,.. .. Beverly, N. J, Arthur R. Guerard,. .. .. Charleston, S. C. Edward Hart,.. .. .. Easton, Pa. Prof. Lewis M. Haupt,. .. . Philadelphia. E. S. Hawley,.....Buffalo, N. Y. John W. Hoffman,.. .. .. Philadelphia. Nelson P. Hulst,.. .. . Milwaukee, Wis. H. C. Humphrey,.. .. . Philadelphia. Ed. P. Jennings,.. .. .Ithaca, N. Y. B. F. Jones,......Pittsburgh, Pa.

THE first session of the Institute was held at the Smithsonian Institution, on Tuesday evening, February 22d. The members were welcomed to Washington and to the Smithsonian by Prof. Joseph Henry. President Holley responded to the cordial welcome of Professor Henry, and then read an introductory address on the subject of Technical Education. Following the discussion on President Holley's address the following persons, duly proposed and indorsed by the Council, were elected members and associates of the Institute : MEMBERS. Emile R. Abadie, - St. Louis, Ma. R. J. Anderson, - Pittsburgh, Pa. Commander L. A. Beardslee, - Washington, D. C. Charles Bender, - New York City. Channing M. Bolton, - Richmond, Va. Thomas E. Bowman, - Silverton, Colorado. Calvin E. Brodhead, - Bethlehem, Pa. M. L. Brosius, - Lewistown, Pa. Harvey H. Brown, - Cleveland, Ohio. James A. Burden, - Troy, N. Y. J. P. Clemes, - Sonora, Mexico. N. H. Cone, - Nederland, Colorado. W. F. Durfee, - New York City. Robert Frazer, Jr., - Ashland, Pa. Joseph E. Galigher, - Bingham, Utah. William Golding, - Steel Works P. O., Pa. Samuel E. Griscom, - Pottsville, Pa. Gen. E. Burd Grubb, - Beverly, N. J. Arthur R. Guerard, - Charleston, S. C. Edward Hart, - Easton, Pa. Prof. Lewis M. Haupt, - Philadelphia. . R. S. Hawley, - Buffalo, N.Y. John W. Hoffman, - Philadelphia. Nelson P. Hulst, - Milwaukee, Wis. H. C. Humphrey, - Philadelphia. Ed. P. Jennings, - Ithaca, N. Y. B. F. Jones, - Pittsburgh, Pa.

Jan 1, 1876

By Norman Pilling

THE solubilities of a series of experimental alloys covering the range 0 to 100 per cent. Ni, 0 to 30 per cent. Cr have been studied under conditions of complete submersion in several fully aerated acid solutions, and in solutions containing sulfurous acid. In nonoxidizing, hydrogen-discharging acids, if the nickel content is below a certain critical amount, chromium increases the rate of solution and nickel decreases this rate; this critical content of nickel is about 13 per cent. Alloys containing more than this corrode at a constant minimum rate independent of iron, nickel or chromium contents. Austenitic chrome-nickel steels may thus have a resistance to these acids equal to that of nickel-chromium alloys. In nitric acid and in unaerated sulfurous acid rather sharp limits of attack occur which are principally dependent on chromium content. In the former the limit of attack is not related to a particular chromium content but varies continuously with acid concentration. The action of sulfurous acid on these alloys is highly dependent on the presence of small amounts of other substances in solution, and many sulfurous acid mixtures rapidly attack alloys to which the pure acid is wholly inert. The observed effects are. not compatible with Tammann's theory relating corrosion resistance to lattice structure but are believed to be concordant with current views of the electrochemical nature of corrosion.

Jan 1, 1929

By W. G. Whildin

This paper will be confined to a discussion of the methods in use in the property of the Lehigh Coal and Navigation Co. in the Panther Creek valley.

Jan 1, 1915

By Frank W. Clinard, Oleg D. Sherby

The effect of multiple an transformations on diffusion in a dilute iron alloy was studied. Inter-penetration between iron and an Fe-Co alloy was evaluated, under thermal-cycling conditions chosen so as to transform only the iron-rich side of the diffusion couple. It is shown that a small but consistent diffusion enhancement by a factor of two results when data from the transforming side of thermally cycled specimens are compared with predicted inter diffusion coefficients based on isothermal data. No enhancement is found when data from the mntransforming side of such couples are compared with predicted diffusivities. It is suggested that short-circuiting by moving pain boundaries is the most likely mechanism contributing to the observed diffusion enhancement from multiple phase transJormations in iron. Transformation-induced Point defects, dislocation-pifie short-circuiting, and point defects generated by dislocation motion are less effective in contributing to enhanced diffusion under the experimental conditions utilized. SO far as is known, no studies have been made of the effect of allotropic transformation on diffusion. previous to this investigation. Studies have been made, however, of the influence of transformation on the diffusion-controlled processes of spheroidization and sintering. Cullen1 has described a method of accelerating spheroidization in an AISI 1030 steel. Partial transformation between a and ? phases was uti-

Jan 1, 1965