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By L. W. Bahney

Many methods for the determination of gold or silver, or both, in cyanide solutions have been published, which with care in manipulation, and modification in some cases, will give results that are satisfactory. It is possible to classify or group these methods as follows: 1. Evaporating the solution in a porcelain or agate-ware dish containing litharge,l or in a "boat" made of lead foil. 2. Forming a lead sponge containing the precious metals by means of zinc shavings,2 zinc dust,3 or a piece of aluminum.4 3. Decomposing the cyanide solution with an acid and precipitating the precious metals by the use of one or a combination of some of the following: Copper sulphate,5 sodium sulphite,6 hydrogen sulphide,' cement copper.ll 4. Precipitating the silver by zinc dust held in a Gooch crucible and determination with a standard solution of sulphocyanate.9 5. Electrolysis.l0 . 6. Colorimetry.ll

Jan 1, 1915

By J. R. Ross, J. B. Rosenbaum

Bureau of Mines research has resulted in the development of fluid- bed ion-exchange columns for recovering uranium from slime pulps. In pilot plant tests, slime slurries containing up to 6 percent solids were processed at flow rates of 10 gallons per square foot per minute with high uranium recoveries and efficient resin loadings. Uranium was effectively eluted in a laboratory fluid-bed elution column at eluate-to-resin ratios of less than 5:1 and eluate flow rates of 3 gallons per square foot per minute. Construction costs of mills using these improved ion exchange techniques are estimated to be 25 percent less than for mills using solvent extraction of clear solutions. For mills having a capacity of 2,000 to 2,500 tons of ore per day, the saving would be in the range of $2.5 million. In addition, a saving of about $0.80 per ton of ore in total operating costs is indicated.

Jan 1, 1973

We would like to thank Mr. Mandolesi for his informative paper on rails from strand cast steel. The chemical and structural properties of the strand cast steel were of particular interest to us. We would like to supplement his excellent report with some of Inland's findings from our Caster with submerged nozzles and strands reduced in line from 7" x 7" to 5-5/8" square cross section. Inland has conducted extensive segregation studies on AISI 1049 steel - Fine Grain 0.50% carbon and 0.75% manganese. Based on approximately 80 heats, our normal segregation pattern results in analyses of .49% carbon in the center, and 0.50% carbon at the midway and edge position. The sulfur analysis averages .025% in the center, .027% midway, and .026% at the edge. Note the slight negative segregation between the center and midway position. This steel, being lower carbon and probably cast nearer the liquidus, resulted in less segregation than the 0.80% carbon rail steel.

Jan 1, 1972

Michigan State Department of Conservation, Lansing, Mich The Department of Conservation has two divisions issuing publications which should be listed in this directory. Geological Survey Division. R. A Smith, State Geologist Land Economic Survey Division L R Schoenmann, Head. A price list of publications of either division will be sent upon request to that division Geological Survey Division.-Citizens of Michigan may obtain publications of this Division on payment of forwarding charges Prices to others for available publications are given below: Vol 5 (1881-1884): Pt 1, Geological report of the Upper Peninsula of Michigan, by L L Hubbard, pt 2, Geology of Lower Michigan with reference to deep borings, by A C Lane, $125. Annual Report for 1908. Pt b, Geological section of Michigan, by A C. Lane and A E Seaman, 50 cents. Publication No 5, The Late Glacial and Post Glacial Uplift of the Michigan Basin, and earthquakes in Michigan, by W. H

Jan 1, 1933

By R. A. MacGregor

The Stanrock mine of Stanrock Uranium Mines Ltd. is located on Quirke Lake in the Elliot Lake area of northern Ontario, about 25 miles north of Lake Huron. The property was developed and brought into production at a rate of 3000 tons of ore per day during the uranium boom of the mid-1950's. The mine workings are from 1200 to 2100 ft below sea level. Mining was done by the room-and-pillar method with 65 to 80% extraction. The plant is located at an elevation of 1400 ft above sea level. The orebodies are conglomeratic beds, 6 to 40 ft in thickness and dipping 5º to 40º. The ore is a quartz pebble conglomerate with a pyritized sericitic matrix. The ore minerals are brannerite, frequently intergrown with anatase or rutile, uraninite, and some monazite and minor coffinite and thucolite. Sulfides constitute 5 to 10% of the ore as pyrite with minor amounts of pyrrhotite, chalcopyrite and galena.

Jan 3, 1969

By J. C. Donnell, O&apos

Sinking an inclined ventilation shaft at the Never Sweat mine of The Anaconda Co. has required a unique underground hoisting arrangement because the shaft changes direction from vertical to 71.5º. Access to the project is made through the High Ore shaft to the 2800-ft level, then by crosscut to the bottom of the vertical Never Sweat shaft. The 71.5º incline shaft starts at this point, which makes an unusual operation as the 60-cu ft sinking skip coming up the incline changes into a vertical position above the 2800-ft level before going into the dump scrolls. This requires both rollers and guide shoes on the skip. Coming up the incline to the collar of the shaft the loaded skip enters into a guard before reaching the vertical section. The tendency of the surface- mounted Never Sweat hoist is to lift the front wheels of the skip off the track, so the guard keeps the skip on the rails during the transition.

Jan 11, 1965

By C. M. Brinckerhoff

Safety work in mining at the Andes Copper Mining Company, Potrerillos, Chile, is divided into three parts: (1) accident prevention, (2) fire prevention and protection, and (3) silicosis prevention and control. In the company's operations a steady campaign has been waged to reduce accidents and silicosis, and to prevent fires. In the following pages the safety record for the past twelve years will be examined and the methods explained by which the accident rate was reduced. Table 1 contains yearly data pertaining to the scale of the mining operations and the accident record. Block caving is used for all ore production and the tonnage mined has aver- aged 30,000 short tons per day for the past seven years. Table 2 classifies 44 fatal accidents which have occurred since 1935. The leading causes of accidental death are transportation of ore and use of explosives, followed in order by per- sons falling, falls of ground, and by asphyxiation. In the case of serious accidents, however, the greatest cause is falls of ground, followed, in turn, by ore

Jan 1, 1949

By Jeff Steinhoff

INTRODUCTION The Henderson mine utilizes a highly mechanized, continuous, panel-caving, mining system to extract ore from a deep, massive, molybdenite deposit. The mine is located 80.5 km (50 miles) west of Denver, Colorado. The mine surface facilities are located 3,170 m (10,400 feet) above sea level in a steep valley on the eastern side of the Continental Divide. Milling facilities are 24 km (15 miles) west on the western side of the divide at an elevation of 2,804 m (9,200 feet) above sea level. The ore- body is located approximately 3,000 feet south of the valley under Red Mountain. Access to the ore for men and materials is through a 915 m (3,000-foot) deep, 8.5 m (28-foot) diameter, vertical, concrete-lined, service shaft. Access from the mill is through a 15.5 km (9.6-mile) rail haulage tunnel. The mine is ventilated through an additional intake shaft and two exhaust shafts. Mine production at this time is 27,255 mtpd (30,000 stpd). The mine ventilation system supplies 1,038 cubic meters per second (2.2 million cfm) through approximately 60 miles of drifting or 2.7 tons of air per ton of ore mined. There are 130 fans in the mine in fixed locations and in vent lines with 6,900 connected horsepower in the mine. MINING METHOD AND LAYOUT The orebody is divided vertically into two major zones. The upper zone is the 8100-level production area. The bottom zone is the 7700- level production area which is in the early development stage. The rail haulage level at 7500 feet is common to both production zones. Each mine production zone consists of five associated sublevels. The cave undercut level is 16.8 m (55 feet) above the production level. Two boundary cutoff levels are located 44.2 m (145 feet) and 62.5 m (205 feet) respectively above the production level. The fresh-air level is positioned 15.2 m (50 feet) below the production level, and the exhaust vent level is 19.8 m (65 feet) below the production level. Horizontally, each production zone is divided into three panels each, 224 m (800 feet) wide. These panels are caved from south to north. As the caving in one panel nears completion, caving in the adjacent panel is initiated. Development for the caving panels is continuous so that the sublevels above the production level and the production level itself have a combination of development drifting and production-related activities. UNDERGROUND VENTILATION NETWORK The ventilation system is zoned in the same manner as the orebody itself. One major split of 600 cubic meters per second (1,270,000 cfm) ventilates the 8100-level production zone; one split of 100 cubic meters per second (210,000 cfm) ventilates the development of the 7700- level production zone; and one split of 165 cubic meters per second (350,000 cfm) ventilates the 7500 rail haulage level. The haulage tunnel requires an additional 188 cubic meters per second (400,000 cfm) of air. Development-drift ventilation is accomplished by hanging 1.0 m (3.5-foot) diameter steel ducting in the drifts with 40-horsepower, 0.96 m (38-inch) diameter fans supplying 9.4 cubic meters per second (20.000 cfm). The normal maximum length for these systems is 300 m (1,000 feet). The 8100-level production-area ventilation system is especially suited to a high level of mucking activity confined in a small area. Approximately 93 per cent of the mine's total production is transferred from the drawpoints to ore passes in 10 production drifts. The active area in each drift is 300 m (1,000 feet). Twelve 5-cubic-yard LHD units with Cat turbo- charged 170-horsepower engines are assigned to the area. Under these conditions, more than one LHD is assigned to a particular production drift. Adequate ventilation is maintained by making an air change every 97 m (320 feet) along the production drifts. Fresh air is brought into the production drifts from the fresh-air level through 1.37 m (4.5-foot) diameter raises. Air travels south along the production drift to the ore pass where it is exhausted down the ore pass to the exhaust level. The ore pass is followed by another intake which is followed by an ore-pass exhaust. At the south end of the production area, a series of exhaust fans maintain a southerly air- flow through the production level.

Jan 1, 1981

By J. S. Browning

The pegmatites of the Kings Mountain-Lincolnton, N. C., area constitute the largest known domestic reserve of beryl and spodumene. The reserve is estimated to contain 90 million tons of pegmatic material with 1,280,000 tons of recoverable Li2O (lithia) as spodumene.1 The pegmatites also contain 0.4 to 0.5 pct beryl disseminated throughout the orebodies. The pegmatites may contain a potential reserve of 240,000 tons beryl, equivalent to approximately 34,000 tons of BeO. Different flotation methods for separating beryl from feldspar or quartz, or both, have been developed by various investigators.2,3,4,5,6,7 On the other hand, published information is limited on concentration of spodumene-beryl ores. As the response of beryl and spodumene to flotation is essentially the same, a successful separation of the two minerals depends upon use of a selective depressant or a selective collector for one of the minerals.

Jan 7, 1961

We did install one 100% brick bottom in our #33 furnace which is basically the same design as Inland's furnace. We had previously embarked on a program of replacing all bottoms in our 300 ton furnaces every 2nd campaign which would be about every 2000 - 2300 heats. This had been necessitated by the effect of our rather high oxygen blowing rates and our desire to maintain a minimum bottom interval level. This meant that we were able to compare bottom performance of various types of materials on a realistic bas is. Since furnace availability is critical to our operation, we are organized to employ every piece of equipment and all the necessary man power to complete a rebuild in the shortest possible time. A 300 ton furnace requires 7.5 days to rebuild. If a new bottom is to be installed an additional 2.5 days is added - 24 hours for tear out and 36 hours for bricklaying - making a total of 10 days.

Jan 1, 1972

By Robert Longyear

IN, diamond-drill work, a true sample consists of all the material cut by the bit-both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little value if an inaccurate sample is obtained. The engineer in charge must study his material and lay out the plan of sampling, and then see that the drill runner follows his instructions; for the runner may be more interested in obtaining a large footage than in developing accurate methods of sampling. FIG. 1.-CORE BOX. When the core has been removed from the core barrel, it should be placed in a core box in the exact order in which it is taken from the ground. This box, Fig. 1, is usually a shallow tray 4 or 5 ft. (1.2 or 1.5 m.) long, with partitions running lengthwise between which the core

Jan 12, 1921

By Frank G. Snyder

The Precambrian of Midcontinent United States includes a metamorphic belt of probable Middle Precambrian age, a belt of Keweenawan volcanics and sediments, and widespread igneous activity that extended from Iowa to Texas. Most of the present structural configuration of the Midcontinent was developed by epeirogenic movements during the Paleozoic. The dominant elements are basins and arches. Three major metallogenic provinces occur in the Midcontinent. They include the Missouri Precambrian iron ores, the Lake Superior copper ores, and the Mississippi Valley lead-zincbarite- fluorite deposits. Several large iron deposits, occurring in rhyolite and andesite host rocks, are known. Both discordant massive bodies and replacement- type bodies occur. The iron deposits are believed to have been formed during the period of igneous activity. They are essentially the same age as the volcanics and older than the granites that intrude the volcanics. The Lake Superior copper ores include two established districts, the Keweenawan district and White Pine, and the copper-nickel deposits in the Duluth gabbro. The lead-zinc-barite-fluorite deposits include four major districts, Southeast Missouri, Upper Mississippi Valley, Tri-State, and Illinois-Kentucky, and at least eight minor districts. Ore may occur in stratiform deposits and in veins. The major districts all contain stratiform deposits, but several have produced appreciable quantities of vein ore. Only vein deposits are known in some of the smaller districts. The major features of all districts can be catalogued in terms of host rocks, structural patterns of districts, types of ore-bearing structures, and mineralogical characteristics. From these features, a Mississippi Valley type ore body, in its type area, can be defined.

Jan 1, 1968

By E. O. Wagner, V. F. Parry

This paper summarizes investigations during 1949 on three pilot plants for drying low-rank fine cool by entrainment in hot gases. Detailed operating results on processing seven coals having moisture ranging from 24 to 62 pct, formulas and data for calculating performance of large units, and general conclusions on the problem of drying fine coal are presented.

Jan 1, 1950

LOCAL COMMITTEE OF ARRANGEMENTS. Major J. W. Powell, Chairman; F. P. Dewey. Secretary; S. F. Emmons, A. S. Hewitt, J. P- Hilgard, Charles Knap, and F. W. Taylor. THE opening session was held in the hall of the new National Museum, on Tuesday evening, February 21st. President Metcalf introduced General W. T. Sherman, one of the Regents of the Smithsonian Institution, who read the following address: ADDRESS OF GENERAL SHERMAN. MR. PRESIDENT AND GENTLEMEN : I have been invited to meet you here this evening to extend to you the cordial greeting of the regents of the Smithsonian Institution, and to assure you that they are most happy to have it in their power to place at your disposal this beautiful hall, dedicated to science and art. This National Museum is the property of the United States, of which the regents of the Smithsonian are simply the custodians, and the board has delegated to its secretary, Professor Baird, the right to extend its use to the National Academy of Sciences and like kindred societies, among which we are glad to class the Institute of Mining Engineers. It is eminently fit that you should meet here at this, the nation's capital, under a roof partly your own, devoted to natural sciences, and in the shadow of the Smithsonian, founded for the exclusive purpose of collecting and diffusing knowledge among men. Of all the workers employed on earth no single class seem to me more worthy the respect of their fellows than those who seek beneath the surface for the useful minerals and metals which contribute so largely to the wealth and comfort of mankind. In no branch of human industry does intelligence come so immediately in contact with labor. To the mining engineer chemistry, mineralogy, and geology are as reading, writing, and arithmetic to the merchant;

Jan 1, 1882

By J. D. Ridge

The geologic setting and mineral relationships of seven European massive sulfide deposits that more or less conform to the bedding of the largely noncal-careous sedimentary rocks and/or bedded volcanics in which they are found are considered here. These orebodies consist largely of massive beds or lenses of sulfides usually surrounded by halos of disseminated sulfides and distorted by tectonic activity. The formations containing these deposits have been metamorphosed in varying degrees at times subsequent to their lithification. The ore-forming process is thought to be essentially volcanic, with the ore constituents being brought to the shallow-water site of deposition through tectonic fissures from magma chambers at depth as gases or relatively concentrated hydrother-mal solutions. Certain European ore deposits of base metal sulfide have previously been considered to be of hydro-thermal or magmatic origin, but today a number of European mining geologists consider them to be syngenetically produced. In an effort to provide American geologists with some idea of the reasons behind this change in thought, the geological settings of seven of these deposits have been studied. These are: Ldkken, Meggen, Rammelsberg, Ergani-Maden, Outokumpu, Boliden and Roros. These deposits lie in bedded rocks that have undergone metamorphism from causes not universally agreed upon; most of the formations were originally shales, and may have been intercalated with limey and occasionally quartzitic beds, volcanic tuff, agglomerate, extrusive lavas and usually basic intrusives. Deposits of the conformable type, however, are not confined to these rock types but may be in calcareous and associated igneous rocks or almost entirely in volcanics. These deposits may be closely associated in space with igneous rocks that, again, are usually basic types. Although the ages of the enclosing rocks range from mid-Precambrian (Boliden and Outokumpu) to Eocene (Ergani-Maden), the bulk of them are Paleozoic, with two (Meggen, and eammelsberg) being upper middle Devonian and two (LØkken and RØros) being Cambro-Ordovician. Geographically, two are in West Germany, four in Scandanavia and one in Turkey. Of the seven deposits, six are mined for copper, with three of these also producing zinc, and two lead; one is mined for zinc and minor lead. In the discussions of the seven conformable deposits that follow, I have attempted to present as uniform a treatment as their varying characters will permit. For each deposit, I have considered the stratigraphy of the area, its major structural characteristics, the form of the orebodies, their mineral content, and the origin of the ore. In the last of these subdivisions, I have presented only the viewpoint of those who believe the ores to have been formed by syngenetic processes, processes that went on at the same time as those which produced the beds that enclose the ores but that are not, in the deposits in question, thought to have been sedimentary in the strict sense of the term. The materials of which these orebodies are composed, it is suggested, did actually collect by falling through sea water to the floor of that portion of the sea in which they accumulated. The ore constituents, however, are believed by a considerable number of European geologists to have been added to the sea water from intratelluric sources, probably igneous magma chambers, as exhalations — hydrothermal solutions or volcanic gases. The effect of the encounter with sea water on these ejected gases or water-rich vapors was to precipitate their potentially solid constituents with great rapidity; they were deposited so quickly, in fact, that the amounj of normally accumulated mechanical or chemical sediment deposited over the same period of time was essentially negligible. The ores formed in this manner, however, are generally interbedded with normal sediments or with lava flows, or with any combination of these two types of rock-forming materials. Such departures as these deposits may have from their original mineral content and attitude are thought to be directly related to the degree of dynamic or static metamorphism that they may have undergone after their accumulation. I have not attempted here to present alternate hypotheses to that of so-called exhalative sedimentation although, of course, such exist and, in my

Jan 1, 1963

By Frederick M. Becket

SHORTLY after the Armistice there appeared a few references to numerous attempts that had been made to produce steel without the aid of manganese, or at least with manganese in abnormally low percentage. Some years later, during two consecutive days of train travel, I had excellent opportunity to read Sir Robert Hadfield's book, entitled "Metallurgy-Its Influence on Modern Progress," and also his paper, "The Metal Manganese and Its Properties : Also the Production of Ferro-Manganese and Its History," presented at the spring meeting of the Iron and Steel Institute, 1927. Both the book and the paper are most interesting historically to makers of alloy steels and

Jan 1, 1931

ALABAMA. Aldrich, Aldrich, W. F. Anmston, Noble, A. E Bessemen, Abbott, C E, Fergusson, V Birmingham, Aldrich, T. H, Aldrich, T. H, Jr, Bowron, J, Burbidge, T A, Collord, G L, Crockard, F H, Davis, F H, Dimmick, F. D., Hiller, E., Johnson, G R, Ludwig, C P., McCormack, G B., McCrery, Peters, R , Jr , Phillips, W B, Ramsay, E ,Shook, A. M Car bon Hall, Pill, J R Emsley, Williams, E P Gadsden, Hudson, J B , Helena, Squire, J Holt, Shook, J W. Huntnnlle, Moss Lehigh, Toulmin. Rock Run, Garvin, J. M. Sheffield, Miller, D I Tusscaloosa, McCausland, E J , Woodward, Woodward, A. H

Jan 1, 1910

By T. Yoshioka, Paul A. Beck

SILICON, germanium, and tin occur with both the white tine-type structure and the diamond cubic structure. In the latter form these elements are semiconductors; in the former they are metallic. The metallic form of germanium and silicon is obtained only under high pressure.' For all three elements the transition from the semiconductor to the metallic state is accompanied by a decrease in the atomic volume of somewhat more than 20 pctily2 Table I. At such a large compression the widening of the s and p bands is sufficient to make the energy gap of 1.1 ev, or less, of the semiconductor disappear, giving rise to the metallic state.*

Jan 1, 1965

E. T. Turkdogan (British Iron & Steel Research Assoc., London, England)—I would like to suggest a different method for the treatment of the authors' data on the Si-0 equilibrium in liquid iron. Because the activity coefficient of silicon dissolved in iron is influenced by the concentration of silicon as well as that of oxygen, the equilibrium constant K2 of reaction 2 becomes a function of metal composition, and, as shown in Fig. 1, a plot of log KP1 at 1600°C against the weight percent of silicon gives a smooth curve. A similar curve is obtained when log Kzl is plotted against the oxygen content of iron. Before

Jan 1, 1955

By F. S. McNicholas

IN the first big blast at Climax, a "loop back" (three-wire system) was used (Fig. I), with the idea of securing a wiring system that would give to all series the same amount of current. Single-phase, 60-cycle, 13,800-volt [ ] power was furnished to the blasting transformers, each of which has a rated capacity of 600 amp. at 480 volts. Two blasting leads were taken from these transformers, giving a blasting current of single phase, 60 cycle, 480 volts, with an instantaneous capacity of more than 600 amp. The blasting switch was on the secondary leads from the transformers, to avoid lag in energizing them.

Jan 1, 1938