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Jan 11, 1961

By Luther Wagoner

For a number of years I have, at odd times, tried to perfect a method of assay sufficiently delicate to find and estimate minute quantities of gold and silver. The object in view was to examine rocks remote from veins or mineral areas, in order to test the probability of the lateral-secretion theory. Having succeeded in measuring approximately the amount of gold and silver contained in one cubic centimeter of sea-water, I present a detailed account of the method employed, with some of the results obtained. General Method of Assay. The use of purified lead without other flux, blowpipe methods, extraction by cyanide, and measurement of the beads by the microscope. Purged Lead. The method of testing is by cupellation. On a properly prepared cupel, it is easy to cupel and find a bead of 0.002 mm. diameter. Such a bead of silver weighs about 1 part of a milligramme. A bead 0.02 mm. in diameter weighs about 1/24,000 mg., and a close approximation can be made to its weight. It is desirable that the lead used in the assay should be low in silver so as to avoid large correction, but as the parted

Jan 1, 1902

By Howard L. Hartman

The past 15 years have seen rapid advances in the metallurgy of materials for drill machinery and bits, but rock drilling itself continues to be largely an art. Jet piercing, roller bit rotary drilling, and rotary percussion are all promising new techniques, but the percussion rock drill, still used for 90 pct of the blastholes in U. S. hard-rock mining, has under- gone no major modification since pneumatic machines were first used successfully in the 1860's. This singular lack of progress stems directly from ignorance of the nature of impact failure of rock and the fundamentals of rock penetration in general. For nearly three-quarters of a century, mining engineers did not know what went on at the bottom of a drillhole.

Jan 1, 1959

By E. D. Peters

The Sudbury ore-deposits possess a peculiar interest for a variety of reasons. In the first place, they are deep within the borders of the Huronian rocks, and are consequently amongst the oldest deposits that we know of, unless, indeed, the ores were deposited at a much later period than the country rock. Again, they carry nickel in unusual proportions, and lastly, they are unique in containing a small amount of platinum, although arsenic is not present. I shall not pretend to go into the geology of this region. The Huronian and Laurentian rocks are familiar to all American geologists, and these present only the usual series of gneiss, graywacke, quartzites, greenstones, clay-slates, etc., characteristic of this gigantic system of rocks, which has excited so much discussion of late years. As in all parts of Canada where it occurs, I believe, the rocks of this system are tilted to such an extraordinary degree that it may be said that the whole country is standing on edge at an angle of something like 70°. The general strike of these rocks is southwest

Jan 1, 1890

Some 30,000 people attended from 50 countries. Over 600 exhibitors brought with them a billion dollars of mining technology, ranging from tiny high-precision valves to giant off-highway trucks. Twenty-seven technical sessions with more than 100 papers covered the gamut of mining advancements. It was a grand display of industry vitality just to power the huge exhibit area required 22,000 kW of electricity each day, and support services for the exposition created more than 1000 daily jobs for local labor. Unquestionably, Las Vagas knew the miners were in town for the American Mining Congress' International Mlining Show.

Jan 11, 1978

Until the end of 1960, the small primary aluminum industry in Australia was run by the government. The entire operation was at Bell Bay on the north coast of Tasmania. It consisted of an alumina plant and smelter, owned jointly by the Commonwealth and the State of Tasmania. Apparent domestic demand that year was about 48,000 long tons; 11% thousand came from Bell Bay; the rest was imported. By March 1964, Australia had two fully integrated aluminum companies. The government has stepped out of the picture and the key word of the industry from bauxite to metal is "growth." Present annual capacity of the two companies for making aluminum metal totals 92,000 long tons a year. Australian demand is about 60,000 tons. By 1968 Australian consumption should be 90,000 tons and by 1970 it is expected to reach 107,000 long tons per year. Export markets for bauxite, alumina and metal are developing.

Jan 10, 1964

Discussion of the papers of DAVID H. BROWNE, Louis V. BENDER, and R. E. H. POMEROY, presented at the New York meeting, February, 1915, and printed in Bulletin No. 97, January; 1915, pp. 49 to 60, 73 to 81, and No. 98, February, 1915, pp. 445 to 453, respectively. E. P. MATHEWSON, Anaconda, Mont.-After hearing about the success of D. H. Browne with his furnaces, we in Anaconda decided we might venture into the field of pulverized coal for reverberatory smelting. We sent a delegation of investigators to see Mr. Browne and his work, and they returned, filled with enthusiasm, and said they would recommend it strongly. We thereupon asked for an appropriation, and after some delay obtained the same and fitted up one furnace to use pulverized coal. We copied Mr. Browne's practice and his selection of machinery for drying and pulverizing coal; and we also copied the burner he used, which was a standard article on the market. We got an expert coal-dust machinery man to design our plant, and were very glad we did so as we avoided some of the unpleasantness that had been experienced at other plants through fires and minor explosions.

Jan 5, 1915

By O. Lietard, J. Yvon, R. Mercier, J. F. Delon, J. M. Cases

INTRODUCTION Fineness is one of the main characteristics of powders and this parameter is the object of several definitions based on criteria connected with their uses as well as their determination methods. In trying to obtain the best reaction surface, fineness is characterized by the determination of the specific surface, but in other cases, particle size analysis is used. These two main methods are not, in fact, entirely independent and their complementary nature provides information concerning the morphology of the particles. In the case of a product formed by isodimensional spheres, the relationship between the specific surface and the diameter is well known: [S = 6 spd] where p is the specific weight of the material and d the diameter of the spheres. With no monodimensional spheres, but rather a granulometric distribution whose occurrences follow a mathematical law (1), the relationship is more complicated. The relationship between the specific surface measured by gas adsorption and the data of the particle size analysis is much more difficult to predict in the case of asymmetric porous particles, whose particle size distribution curves do not correspond to a known statistical law.

Jan 1, 1980

By Laurence Hicks

CONSIDERATION of the past work on the subject of the diffusion of chromium into iron suggested that additional information might be given by the use of X-ray spectroscopy in following the concentration changes through the diffusion zone. Grübe and Fleischbein1 packed rods of electrolytic iron in a mixture of alumina and chromium. These specimens were heated in an atmos-phere of purified hydrogen for varying lengths of time. After treatment the specimens were examined metallographically and showed the usual structure, consisting of a border of radially oriented columnar grains ending in a sharp boundary line. Reference is made to the fact that etching with certain reagents will attack only the material inside the border of columnar growth and also to the fact that polishing seems to develop a ridge at the position of the boundary between the etched and unetched areas. By chemical analysis of thin layers turned off on a precision lathe, the authors were able to obtain depth-concentration curves. These curves, reproduced in Fig. 1, show that 'in most cases a pronounced change of slope occurs, corresponding to the position of the boundary of the columnar grains. In a later paper Grübe extends his work to other systems which show the same characteristics.2 He concludes that the reason for the break in the curve is that a hindrance of diffusion occurs at the place where the regularly oriented grains of the diffusion zone meet the random grains of the interior portion, on the assumption that the diffusion velocity in one direction in a grain may be greater than in another direction, and that the grains in the diffusion zone orient themselves so as to give the maximum diffusion rate. Kelley3 points out that Grübe has failed to note that the boundary line does not consistently cross all grains and

Jan 1, 1933

By J. O. Brittain, E. P. Lautenschlager, D. A. Kiewit

Compression tests were run in the temperature range of 700° to 900°C ox 0' phase NiAl intermetal-lic alloys of several grain sizes. At these temperatures the minimum strengths were observed at the stoichiometric composition. While significant increases in strength occurved in both the low-nickel (vacancy) and high-nickel (substitutional) regions, the highest strengths were found in the high-nickel region. During deformation serrated flow was sometimes observed in the low-nickel alloys. After deformation transgranular cvacking and deformation striations were observed in all compositions tested. AS part of a general investigation of the properties of NiAl inter metallic compounds, a preliminary study of the role of point defects upon plasticity was made by high-temperature compression tests on ß' NiAl specimens of several grain sizes and compositions. ß' NiAl is an intermetallic compound having a CsCl structure and a rather wide range of composition from A1-45 at. pct to 60 at. pct Ni.1 According to Bradley and Taylor2 and to cooper,' it possesses a defect lattice in which departures from stoichiometry in the direction of decreased nickel content lead to the presence of vacant nickel sites (although Cooper's work indicates that a small amount of substitution also occurs) whereas departures on the high-nickel side lead to substitution of nickel on aluminum sites. NiAl forms congru-ently from the melt at approximately 1650°C,1 and thus has a higher melting point than either of its component elements. Up to this time, although this and other high-melting intermetallic compounds have been suggested for elevated-temperature usage,4 only the hardness4 and a few tensile-strength measurements5 have been reported for NiAl at high temperatures. In the present investigation the effects of composition upon the compressive-strength properties in a range of 700° to 900°C have been measured for NiAl of several grain sizes. EXPERIMENTAL PROCEDURES The alloys were made as described elsewhere6 from an A1-46.8 at. pct Ni master alloy furnished by the International Nickel Co. with additions of high-purity nickel and aluminum. The charges were vacuum-induction-melted in A12O3 crucibles with small amounts of helium added to the atmosphere to suppress vaporization. They were cooled slowly from the melting temperature to achieve uniform grain size. In order to refine the as-grown grain size a special rolling technique was developed. Alloys were packed into 0.10-in. wall-type 302 stainless-steel tubes which were partially filled with magnesium oxide to prevent bonding between the alloy and the steel jacket. The ends of the tubes were closed by hot forging, and the packets were then hot-rolled. The alloys with greater than 50 at. pct Ni were rolled at 1100°C, but it was found necessary to increase the temperature to 1350° C before alloys with less than 50 at. pct Ni would roll without cracking. With these temperatures, reductions as high as 48 pct were achieved in a single pass. The rolled alloys will hereafter be referred to as "fine grained" whereas the as-grown material will be designated "coarse-grained''. The compression specimens were made by cutting square cross-sectional pieces, approximately 3/16 by 3/16 by 1/2 in., with a water-cooled diamond cut-off wheel from the as-grown or the rolled alloys. Specimens were ground to their final dimensions by polishing through 3/0 grit silicon carbide papers. The final shape was a rectangular parallelepiped of square cross section having a height-to-width ratio of 3:1. Compression testing was carried out in a compression rig of our own design mounted on an In-stron Floor Model. The specimen chamber could be heated to 1000°C and was controlled within ±2°C. The compression rig was enclosed within a bell jar and was maintained at a 50 µ of mercury vacuum throughout the duration of the test. The test cham -ber was heated from room to test temperature within 15 min. Specimens were then held at the test temperature 30 min prior to testing. Previous experiments indicated that no grain growth would occur within this time. An Instron Variable Crosshead speed unit was used to adjust for small variations in specimen lengths in order to have a constant initial strain rate, €, for all specimens of a group. For the fine-grained specimens the strain rate was changed rapidly at constant temperature by a factor of 10 with the speed lever on the Instron. For a given € the compression data was analyzed in terms of true plastic strain (E) and true compressive stress (0).

Jan 1, 1965

By T. Clinton Taylor

QUALITATIVELY, galena (native lead sulfide) reacts with aqueous solutions of the xanthates,1 and has its surface sufficiently altered so that there is a tendency for air bubbles to attach themselves to the mineral crystals where there was no such effect before the treatment. This property is utilized in froth flotation operations where the mineral sulfide particles are raised into the froth and the gangue whose surface is not altered remains behind. The results of a study of this reaction were reported" recently and certain tentative suggestions about the interaction of galena and the alkali xanthates were offered. In this paper, there is set down the results of a detailed quantitative investigation of the ions involved in this inter-action with a view to finding out more about the condition existing imme-diately at the surface of a crystal like a heavy metal sulfide after treatment with an organic reagent. Past experimental experience showed that finely ground galena shaken with aqueous potassium xanthate abstracts xanthate ion and at the same time sulfate ion, reducing ions of the type (SmOn)= where the ratio of m to n is less than 4:1 (as in sulfate), sometimes hydroxyl ion are thrown into solution.,

Jan 1, 1933

NEW MEMBERS The following list comprises the names of those persons who became members during the period Apr. 10 to May 10, 1914: Members ADAMS, HENRY H., JR., Merchant, Henry H. Adams & Co., and Colonial Iron Co., 149 Broadway, New York, N.Y. ADAMS, LELAND D., Mine Mgr., Supt., East Canada Smelting Co.,Weedon, Quebec, Canada. AGUILERA, EUGENIO, Chief Engr. Mining & Foresting Dept. of Santiago, Santiago de Cuba, Cuba. ALFORD, NEWELL GILDER; Min. Engr., Asst. Chief Engr., St. Bernard Mining Co,. Earlington, KY.

Jan 6, 1914

By Albert Roberts

Summary In response to a growing intolerance towards ground vibrations and noise as environmental pollutants the engineer must consider the effects of his operations as they are likely to be judged subjectively by the public at large. Much work has been done on the study of vibration damage to structures, but the damage criteria normally applied do not take into account any resonance effects, nor do they embody any subjective criterion. Mu1tiple criterion techniques of subjective appraisal have proven to be of value .in the assessment of environmental comfort in relation to ventilation, air conditioning, and lighting. One such scale, the Reiher-Meister Scale, has also been applied to ground vibrations and noise, and an attempt has been made to correlate this scale with objective criteria, using the parameters of frequency and displacement. This paper quotes examples and compares ground vibrations resulting from blasting, the operation of, vibrating and impact-hamner pi1e drivers, forge hammers, and railway and road traffic. The Reiher- Meister Scale was applied to a subjective-objective correlation in relation to vibrations from railway traffic and gave results which did not conflict with experience.

Jan 1, 1971

By James P. Kimball

BY the term weathering of coal is meant the process of deterioration to which under various circumstances it may be exposed at ordinary temperatures, both from outward agencies on the one hand, and on the other hand from its own constitutional qualities. This process involves along with some minor qualitative changes certain quantitative changes resulting in a gradual and limited reduction in the quantity of the organic elements, and relatively a corresponding increase of its inorganic or mineral constituents as represented by its ashes, and often in an increase of the absolute weight of the coal. In common with many mineral substances, coal absorbs oxygen

Jan 1, 1880

By James E. York

The honor so fairly earned and so incompletely and tardily paid to Henry Cort, the inventor of the puddling-furnace and the rolling-mill, has been fully set forth by Mr. Charles H. Morgan,' and needs no further emphasis here. In view of the importance of the rolling-mill in the treat ment of iron and steel, the paucity of information concerning it is surprising. With the exception of a book, written about 35 years ago, by Peter Ritter von Tunner, an Honorary Member of this Institute, and of desultory articles on simple sections, which have appeared in technical journals, I know of no publication attempting to treat this subject, although volumes have been written on the scientific theory and technical manipulations involved in other branches of the iron- and steel-industry. This strange anomaly may be due to the fact that roll-turning cannot be called a scientific business. It does not ordinarily come within the range of an educated engineer; yet it cannot be performed by an ordinary mechanic. It demands some of the qualifications of an engineer, in designing, and those of a mechanic, in execution. The men who have followeci this trade have controlled the training of their successors. In many cases the technical knowledge required has

Jan 1, 1907

By James P. Kimball

By the term weathering of coal is meant the process of deterioration to which under various circi~mstances it may be exposed at ordinary temperatures, both from outward agencies on the one hand, and on the other hand from its own constitutional qualities. This process involves along with some minor qualitative changes certain quantitative changes resulting in a gradual and limited reduction in the quantity of the organic elements, and relatively a corresponding increase of its inorganic or mineral constituents as represented by its ashes, and often in an increase of the absolute weight of the coal. In common with many mineral substances, coal absorbs oxygen

Jan 1, 1880

By F. W. Gibson

A detailed description of the smelting and refining operations of the Amax-Homestake Lead Toller's smelter at Buick, Missouri. This is one of two completely new lead smelting and refining operations to go into operation in the United States in over forty years. Incorporated into the operation are the new methods and equipment which have been developed and lend themselves to the particular metallurgy of this plant. The text, as well as the statistical data presented, represent actual current practice after 22 months of operation, and although the metallurgy is considered to be relatively simple, several metallurgical problems unique to Missouri concentrates are discussed.

Jan 1, 1970

By Robert Burrows

IN preparing this paper the object has been to set forth facts relating to illumination problems, which, judging from the results realized in the iron and steel and other industries somewhat similar to mining, will tend toward furthering safety, production, and contentment of employees, as well as economy of operation in mines. By applying the principles of illumination with the assistance of modern appliances, the full benefits in efficiency may be derived from improvements already made in other details of mine operation. The lighting of a typical coal mine may be divided into four distinct parts: 1, The lighting of the buildings about the top; 2, the lighting of the working faces; 3, general illumination at the bottom; and 4, special applications of lighting. The lighting of buildings about the top may be treated in the same manner as that of any other industrial plant, for we have a boiler room, an engine and generator room, a forge, a machine shop, and a hoist room. These can be well and efficiently lighted by the use of 100-watt tungsten-filament multiple lamps with proper reflectors so spaced and suspended that a power consumption of from ¼ watt per square foot in the boiler room to 1 watt per square foot in the machine shop is obtained. The methods that apply to this kind of lighting have been ably treated by a number of authors,1 and for this reason a detailed discussion is unnecessary.

Jan 11, 1915

NEW MEMBERS The following list comprises the names of those persons who became members during the period Mar. 10, 1916 to Apr. 10, 1916. ALLEN, P. R., Pres., McAlester Coal & Coke Co., Knight Templar Bldg., McAlester, Okla. BERNARD, CLINTON PERCIVAL, Min. Engr., Care Forminiere Mission Kasai, Tschikapa, Congo Belge, W. Africa. CARPENTER, GEORGE 0., Vice-Pres National Lead Co. St. Louis Mo. CLARK, WILLIAM ANDREWS, JR., Min. Engr., Pres., Elm Orlu Mining Co., Butte, Mont. CLAYTON, CHARLES YANCEY, Asst. PrOf. of Metallurgy and Ore Dressing, Missouri School of Mines, Rolla, Mo. COHEN, JULIUS MILTON, Mgr. Croesus Gold Mines, Ltd., Matheson, Ont., Canada. CRAMER, WILLIAM BRONSON, Met. at Concentrator, Old Dominion Copper Min. & Smelt. Co., Globe, Ariz. DAHL, SIMEON H., Mill Supt., Messina Transvaal Dev. Co., Messina, Transvaal S. Africa.

Jan 5, 1916

NEW MEMBERS The following list comprises the names of those persons who became members during the period of Aug. 10, 1917, to Sept. 10, 1917. ADKERSON, J. CARSON, Mgr., Stockwood Realty Corporation, Inc. Woodstock, Va. ARAKAWA, EIJI, Min. & Met. Engr., Min & Met. Dept., Imperial Univ., Kyoto, Japan. BAINS, THOMAS MELLOR, JR Major, Officers' Reserve Corps, Presidio, Cal. BARTON, Louis ARTHUR.. , . Vice-Pres., Adbar Development Co., Dewed, Minn. BLACKSTONE, ALEXANDER J....Asst. Engr., Honiestake Min. Co., Lead, SO: Dak. BOGARDUS, CHARLES EUGENE, Assayer & Chem., Bogardus Testing Laboratories 90 Columbia St., Seattle; Wash. BOISE, DAVID WELLS Chief Clerk, Chino Copper CO., Burley, New Mex. BREEDING, FRANK OWEN Assayer, Eden Min. CO., Bluefields, Nicaragua. BRUYERE, ALAN, Petroleum Geol., Producers' Oil CO., Box 96, Shreveport, La. BUTTS, ALLISON, Asst. Editor, The Mineral Industry, Lehigh Univ., So. Bethlehem, Pa. CALVERT, CLARENCE E Safety Engr., Anaconda Copper Min. CO., Butte, Mont. CHARLTON, HARRY.... Min. Engr, Commonwealth Edison CO., Taylorville, 111. CLAGUE, HERBERT NADEN, Surveyor.. Duncan, V. l., British Columbia, Canada. CLOSE, FREDERIC BAGLEY The Rampart, Los Angeles, Cal. COLLIER, DAVID HENDERSON, Mine Supt., Thumb, Butte Mines Co., Kingman, Ariz.

Jan 10, 1917