Search Documents

By M. H. Gidel, D. C. Bard

These notes are based on the megascopic study of a suite of 2,400 specimens of minerals and ores from the Butte mines, combined with field observations at intervals over a period of several years. The estimate of average vein composition is based on field acquaintance with the veins. It is probably correct in its broader proportions, and should be of use for comparison. Chemical and Mineral Composition of Unoxidized Vein Matter. Per Cent. Oxygen,......48.00—Quartz, rhodonite, rhodochrosite, sericite, kaolinite, barite, calcite, and hübnerite. Silicon,...... 36.O0—Quartz, rhodonite, sericite, kaolinite, and willemite (very rare). Sulphur,.....5.0—Sulphides of iron, zinc, copper, lead, and sulphates of barium and rarely calcium. Iron,.......5.00—Ferric sulphides (pyrite, bornite, chalcopyrite), also in sphalerite, tetrahedrite, and rarely hematite and siderite. Manganese,.... 2.00—Rhodonite, rhodochrosite, and hübnerite. Zinc,.......1.00—Sphalerite, very rare wurtzite and willemite, and tetrahedrite and tennantite. Carbon,......0.50—Rhodochrosite and calcite. Capper,......0.75—Cuprous ( + ) and cupric (—) sulphides. Aluminum,.... 0.50—Sericite and kaolinite. Hydrogen,.... 0.50—Water, sericite, and kaolinite. Potassium,.....0.20—hicite. Lead,....... 0.20—Galena. Arsenic,......0.10—Tennantite and enargite. Barium,......0.10—Barite. Calcium,.....0.10—Fluorite, calcite, and rare gypsum. Antimony,.... 0.02—Tetrahedrite, famatinite, and silver sulphantimonites. Fluorine,.....0.05—Fluorite. Silver,.....1 —Argentite, and sulphantimonites. Tungsten,.... —Hübnerite. Phosphorus, • —Wavellite. Bismuth,' .... 0.05—Sulphide (?) Tellurium,... 1 —Telluride (?) Selenium,.... —Selenide (?) Cadmium,.... —Sulphide (?) Gold,..... —Native and telluride (?)

Jan 1, 1914

By Leonard Larson

Before direct or wet smelting of copper concentrate was adopted at the McGill smelter, in November 1932, actual furnace smelting tests had indicated the possibility of smelting between 400 and 500 dry tons of wet concentrate per furnace day. Under calcine smelting practice, solid charge up to 116; tons per furnace day had been smelted. It was realized that in order to smelt wet tonnage in equivalent amount per furnace day, a higher combustion rate and higher temperatures would be necessary within the furnace. The reverberatory furnace considered in the following history of wet-smelting developments is a unit rz7 ft. long and 28 ft. 8 in. wide, inside dimensions (Fig. I). This furnace was in operation through all the years from 1934 to date. During 1933, the first complete year of direct or wet smelting, the plant was on a curtailed copper-production basis and the available concentrate tonnage to be smelted was limited. The average coal-firing rate in the reverberatory for that year was 124 tons per furnace day. This rate was lower than the average for years immediately preceding under calcine smelting practice. With this coal-firing rate, an average of 391 tons of new metal-bearing material (N.M.B.M.) was smelted per furnace day. The following year, 1934, the coal-firing rate was increased to 139 tons and the smelting rate increased to 448 tons N.M.B.M. per fur- nace day. In succeeding years production required that either more tonnage be smelted in the one furnace or an additional furnace be placed in operation. With this situation confronting the smelting department, it was determined to continue the program of increasing the coal-firing rate and also to intensify the temperature in the smelting zone of the furnace. In order to accoinplish this, various improvements were made to aid combustion within the furnace. The burners were enlarged, increased primary air was supplied to the burners, and changes were made in the furnace to enlarge and streamline the outlet, thus increasing the furnace draft. The coal-firing rate was increased yearly until 1937 when the firing rate averaged 210 tons per furnace day. Thereafter the firing rate fluctuated according to character of charge and production requirements. In general, however, with the same character of charge the smelting rate increased in almost direct proportion to the increases in firing rate. Table I shows the average coal-firing rate, smelting rate, and other pertinent data for the direct-smelting years of 1933 to 1939 inclusive, the first fivc months of 1940 and May 1940. These figures show that the water evaporated in the waste-heat boilers was in almost direct proportion to the coal-firing rate. In making comparisons in the table, it should be borne in mind that the figures, except for May 1940, are yearly averages. Because of changes in character of charge or operating conditions, records for individual days or even months

Jan 1, 1944

By W. F., Netzeband

SEVERAL criteria have been used more or less successfully in finding and developing orebodies in this district. Among them is the relation of the fracture to the orebodies. It has been known for some time that there was some relation, but it has been but recently. that careful study has been given to this subject. Like all the criteria used in this district, this relationship must be used with caution, for what-is true in one part of the district is not necessarily true in another.

Jan 1, 1928

By P. W. Harben

Jan 1, 1985

By Eric Jette

The nickel-chromium alloys form the base f for many industrial heating alloys, so that this system is of considerable practical importance. The literature on these alloys, however, contains much conflicting evi-dence, not only regarding the solubility limits of the terminal solid solu-tions at different temperatures but even regarding, the number of phases existing in the system. Part of the difficulty undoubtedly arises from the fact that chromium of sufficiently high purity has been available only during the last few years. A second and possibly even more impor-tant difficulty arises from the ease with which chromium reacts with silicon and carbon compounds and the atmosphere to form silicides, carbides, nitrides and oxides. Pilling and kihlgren1 in 1929 reviewed the existing scanty information. They did not consider the diagram by which they summarized the various bits of information to be entirely satisfactory. Matsunaga2 investigated the system by thermal analysis, microscopic examination and other means. Electrolytic nickel of 99.9 per cent purity and thermit chromium containing 0.30 per cent al, 0.40 per cent fe, 0.25 per cent si and 0.04 per cent c were used. A tammann furnace with hydrogen flowing through it was used for melting. Sekito and matsunaga3 reported an x-ray, investigation presumably on these same

Jan 1, 1934

By Alfred H. Bell

The year 1937 has been outstanding in the history of the Illinois oil industry. During the course of the year the state's daily production has been trebled, increasing from 12,000 bbl. per day at the beginning to 37,000 bbl. per day at the end, and the year's total, 7,426,000 bbl. is 66 per cent above the previous year's production of 4,475,000 bbl. The production in January was 368,000 bbl.; in December it was 1,085,000. Production from the old fields increased slightly. Most of the new production is from fields in the central part of the Illinois Basin, an area that for many years was considered unfavorable to the occurrence of oil and gas. The principal producing horizon of the new fields is the McClosky "sand," an oolitic limestone in the Ste. Genevieve formation of lower Mississippian age. Although development has not yet gone far enough to permit accurate estimates of oil reserves in the new fields, it is believed that they are of the order of 100,000,000 barrels. The following are the oil fields discovered in 1937 listed in order of amount of daily production at the end of the year; Noble (Richland County), Clay City, including Southeast Clay City (Clay and Wayne counties), Patoka (Marion County), New Centralia (Clinton County), Olney (Richland County), Cisne (Wayne County),.Beecher City (Fayette County), and Rinard (Wayne County). One gas field, the Russellville, in Lawrence County, was discovered in 1937. For locations of the new fields see Fig. 1. A generalized geologic column for Illinois, showing producing horizons in the new fields, is given in Fig. 2. The total productive area of the new fields at the end of 1937 was 1712 acres, in which 230 wells were producing. Thisrty-five dry holes were drilled within 1/4 mile of producing wells. At the end of the year there were 19 drilling wells, 28 rigs standing, 18 rigging up and 4 new locations in these fields. In the whole state 447 wells were completed, of which 284 were oil producers and three gas producers. Total initial daily production of

Jan 1, 1938

By George Hunt

THE first practical treatment of wood to prevent decay was devised early in the 19th century. At that time the oaken navy of England, when . the nation was fighting for its very existence, seemed doomed to annihilation by the swift ravages of decay. The acute situation inspired a desperate search for preventive measures and resulted in the development of the Burnett, Bethel and Kyan processes for impregnating wood with zinc chloride, coal-tar creosote and mercuric chloride, respectively. In the century that has elapsed, their use has spread throughout the world and the three original preservatives are used today in enormous quantities. Meanwhile, improved processes have been developed, new preservatives discovered, and the practice of impregnating wood to make it last longer has attained a position of major importance in the field of structural materials. USE OF PRESERVATIVES BY- THE RAILROADS In the application of wood preservatives in the United States the railroads have been the leaders for the past 50 years or more.. Having found, that decay is the chief cause of the early destruction of wood and that preservative treatment is the remedy, they have treated their ties and timber in increasing amounts(1) ?-in 1925 about 220,000,000 cubic feet. By preservative treatment the Santa Fe Railroad saves annually 1,500,000 ties in its 18,000 miles of track, and many other railroads effect similar savings. (2) In like manner the life of wooden bridges and trestles,(3) poles, marine piling, water tanks and other wooden railroad structures has been greatly increased, reducing the amount of timber required annually to maintain them.(5),(7)

Jan 2, 1927

By LEWIS F. THOMAS

MINING geologists and mining engineer, rarely give due thought to the geography of mining deposits. They realize, it is true that what may be ore in one place would be only worthless rock in another because f the in accessibility of a smelter r a market; and they may consider the lack of a supply of labor, or water, or power to carry on operations. But they do not think (of these things in terms of geography. Geography may be defined as the science of relationships between earth and man, so geographers are vitally interested in the how and why of mining as it is carried on at different place, having entirely different environment-. Such environments are geographic complexes or composites of natural and cultural elements, which are listed and briefly discussed in the following paragraphs.

Jan 1, 1941

By George Anagnostache

AMONG the petroleum-producing countries of the world, Roumania occupies the fifth place; in Europe, it occupies second place, coming after Russia. The extraction and the use of petroleum in Roumania, may be trace( as far back as 1856, but the production on an industrial scale started in 1896, when the "Steaua Romana," was formed. From that time until the beginning of the war, the petroleum industry had a rapid growth the number of the producing companies increased to 37, and production FIG. 1.-ROUMANIAN OIL AND GAS FIELDS. increased from 81,571 tons, in 1896, to 1,898,545 tons, in 1912, when the greatest production was reached. In 1916, when the Germans invaded Roumania, the oilfields, at the order of the Allies and under British supervision, were destroyed, to pre vent their exploitation by the Central Powers; the wells were blown in the refineries and the storage tanks burnt, and pipelines put out of order This voluntary destruction, which weakened the resistance of the Central Powers, set back the petroleum industry at least one decade. Reconstruction after the war was slow, because of bad transportation conditions the scarcity of drilling and refining material, the insufficiency of. electric power, and the continuous depreciation of the Roumanian money, which made difficult the buying of the necessary materials for reconstruction.

Jan 3, 1925

By M. E. Wadsworth

"For his creative efforts in explaining the electrochemistry of sulfide mineral leaching systems." Leaching reactions that occur during the dissolution of selected base metal sulfides and metals are considered in terms of surface reactions and the influence of intermediate or final products formed. These products may be solid layers, requiring solid phase diffusion for the reaction to proceed, or ions in solution that can influence the kinetics by controlling the mixed potential of the solid. Three general types of reactions are proposed to explain observed rates of reaction. Examples are presented for non-oxidative and oxidative leaching of galena (PbS), anodic dissolution and oxidative leaching of molybdenite (MoS2) and cyanidation of silver and gold.

Jan 1, 1986

By GILBERT C. DAVIS

ANY thought of Morenci naturally includes its sister town of Clifton, its gateway to the outside world. Clifton, the country seat of Greenlee County, is the terminus of a branch line of the Southern Pacific railroad from Lordsburg, N.M. Carload freight incident to the Morenci operation moves from Clifton over Phelps Dodge?s standard-gauge industrial railroad. Private freight must be hauled by truck. These two communities fell far short of supplying adequate housing for the personnel concerned with the new operations so a new townsite, Stargo, was developed adjacent to Morenci. Here 234 housing units with garages have been built and twenty similar units have been erected near the reduction works.

Jan 1, 1942

Jan 1, 1892

By Ralph H. Sweetser

IN these days of the almost exclusive use of byproduct coke as the blast-furnace fuel in this country, it may seem out of place, and smacking too much of reminiscing, to say anything about the use of anthracite coal for blast-furnace fuel. Viewed in the light of present day research and of developments in alloy steel, some observations seem appropriate regarding this raw material that played such an important part in the development of the iron and steel industry during 50 years of the past century. The research work of that period, in which the whole iron and steel industry was revolutionized, passing from wrought iron to steel and from charcoal to three new mineral fuels for blast furnaces, was done chiefly in the full-sized plants of that day; and it was done largely by the ironmasters themselves. The laboratory had not become a part of the ironworks, and scientific instruments were lacking around the blast furnaces; "rule o' thumb" and erroneous theories prevailed-and have not yet all been eliminated. The recent interest in meteoric iron in connection with nickel steels and other alloys proves that it is worth while to search for the reasons for excellence and the causes for failures in the metallurgy of bygone days. Turner1 gives the reasons why the blast furnace of Dr. F. W. Geissenhainer on Silver Creek, Schuylkill County, Pennsylvania, about 10 miles northeast of Pottsville, was operated successfully with anthracite2 in August and September, 1836, and why several other attempts failed. It has taken a long time for us to find out that there are great differences in the behavior of anthracites from the several parts of the anthracite region, as well as differences in coking coals from the bituminous fields.

Jan 1, 1935

Jan 1, 1930

By J. S. Kirkaldy, R. C. Dorward

The solubilities of copper and gold in silicon and germanium have been determined by equilibration of the solid semiconductors with coexisting liquidus phases. The experimental results were combined with estimated activity coefficients of the liquidus alloys to determine the following partial molar enthalpies and excess entropies of solution for the systems: Solubility measurements were also carried out below the eutectic temperature of the copper-silicon system. The partial molar enthalpy and excess entropy of copper in silicon with respect to Cu3Si were determined to be 40.2 ±0.5 kcal per mole and 9.7 i 0.5 cal per mole — OK, respectively. It has been dentonstrated that nu-cleation and growth of intermediate compounds are retarded in copper-silicon diffusion couples. This points out the dangers of determining equilibrium solubilities by dijjusion methods. THE thermodynamic requirement for equilibrium between contiguous phases at constant pressure and temperature is that the chemical potential of each component be constant throughout the system. Equating expressions for the chemical potential of solute, component 2 say, in two phases, alpha and beta, gives

Jan 1, 1969

By Roy Neal

THERE are two main sources of the water that floods productive oil or gas sands. The water may rise from the lower depths of the producing stratum, or it may come from beds above or below the oil-bearing formation. Usually the recovery of oil is decreased by water entering the oil sands, and most oil-field waters, especially those of deep wells, tend to foster the formation of an emulsion, which is expensive to treat. This paper deals with a method of distinguishing between waters that encroach upon oil-bearing, beds from sources in the same stratum and waters .that reach the oil sands from horizons above. In order to remedy effectually water difficulties in oil and gas wells, it is absolutely necessary to determine the source of the invading water. Sometimes evidence such as the structural relations between the strata penetrated by neighboring wells and those found in the well under investigation is not adequate; also, data from drill logs and well records, from mechanical tests made on the wells by plugs, testers, drilling tools, etc., and from tests by chemical indicators such as eosin and Venetian red, may he unsatisfactory, for such data may fail to locate the source of the infiltrating waters. As a resort in such cases, the application of chemical analyses, that is, the comparison of an analysis of the water in, question with that of typical waters from the various water horizons in that particular district, has in certain instances proved of value. This method has been used to advantage in the Westside Coalinga field of California, where the source of water may be fairly definitely determined from its composition. The chief conclusions concerning the chemistry of the oil-field waters in California by G. S. Rogers1 are: "Oil-field water is not necessarily salty, as is generally believed, and may not be even slightly salty to the taste. The degree of concentration of chloride in such water is governed primarily by local conditions and is not affected by the position

Jan 1, 1919

By J. D. Jones

Unique aspects of tailing pond design aid reclamation facilities for three separate projects are described.

Jan 1, 1978

By Phyllis A. Lyday

Jan 1, 1985

By C. N. Stout

Square-sets go out and labor saving combination of top-slicing and sub-level caving raises tons per man hour 300 pct, cuts timber cost 50 pct to permit mining lower grade ores.

Jan 1, 1953

By Richard Pearce

IN looking around me for some subject on which to frame an address for this meeting, it has occurred to me that some results of observation and investigation, in regard to the varied conditions under which gold is found, may possibly prove of interest. The subject is one which frequently crops up in discussions at our meetings, but there is always an immense amount of uncertainty expressed as to the actual condition in which the gold exists in any particular ore. It follows, therefore, that any light which might be shed on this rather complex subject, would be of value to science and of service to mining and metallurgical practice. In some investigations which I have, from time to time, been led to make, for the purpose of determining to what extent an ore might be concentrated, I have been astonished at the very varied and apparently inexplicable results encountered, and have been naturally led to inquire into the causes for such seeming inconsistency. The mines of Gilpin county, Colorado, where gold was first discovered in that State, furnish an infinite variety of examples of its occurrence, and it was here that difficulties first presented themselves to the Colorado miners, in the sudden transition from what is called " free-milling gold-ore " to an ore characterized by properties which make the ordinary treatment by amalgamation stamp-mills utterly impracticable. So long as mining was limited to what might be called the zone of oxidation in the veins, just so long might amalgamation be conducted without difficulty; but directly the miner reached a point beyond the influence of the oxidizing power of the surface waters, the gold resisted all attempts at amalgamation, and recourse • was had to smelting.

Jan 1, 1890