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By Robert Hopler

RBH Note: At the time of this price list the handwriting was already on the wall regarding the ultimate breakup of the company under the Sherman Anti-Trust Act. The brand names Atlas and Hercules, noted on page 3 of this pricelist, would become the names of the new companies created from du Pont.

Jan 1, 2012

By G. Sommer, R. P. Chaix, G. T. W. Ormrod

Recent developments in the instrumentation and automation of uranium-processing plants by G. SOMMER, Ing. (Grad.) (Visitor), G. T. W. ORMROD (Visitor), and R. P. CHAIX, B.Sc. (Visitor) The paper discusses work at the National Institute for Metallurgy on the evaluation of measuring techniques for the automatic control of free acid in leaching. of the ratio of ferric to ferrous ion in leaching, of pH in liquid-liquid extraction. and of uranium in loaded solvent. Commercially available instruments. and the modifications that have been made to adapt them to South African uranium plants, are also described.

By Denise Y. Dixon

The objectives of this study were to (1) document the hydrologic impacts of longwall mining on ground water, (2) identify the factors which affect the extent of dewatering, and (3) develop empirical trends to predict the extent of dewatering and recovery in advance of mining. The study was confined to three mine sites in north-central West Virginia. At each site, available ground water supplies were identified and monitored for dewatering effects and recovery. Mine A, located in Upshur County, West Virginia, has relatively thin overburden (approximately 715-280 feet). At this site domestic water supplies and specially constructed monitoring wells were monitored, continuing with an earlier study done by Cifelli arid Rauch. Most such supplies were completely dewatered over the longwall panel. Some of these wells have shown significant recovery, especially near a stream. Extensive monitoring of two nested piezometer wells revealed that dewatering generally started in advance of undermining in the lowermost monitored overburden zones first and then progressed upwards. Most dewatered wells completed in bedrock have shown no recovery, except. for valley drilled wells located within 100 feet of a Stream. Affected dug wells completed in valley alluvium rend located within 200 feet. of the nearest stream have shown significant recovery. Some wells have partially collapsed following mine subsidence. Mine B, having relatively thick overburden (approximately 585 to 900 feet), is located in Monongalia County, West Virginia. Ground water supply surveys have been conducted there in an attempt to study past dewatering effects. Owners reported Chat several wells were dewatered by longwall mining arid vertical air shafts that preceded longwall mining. Dewatered wells over longwall panels hove shown some recovery within 3 ½ years of mining. Mine C also has relatively thick overburden (approximately 585-900 feet), and is located mostly in Greene County, Pennsylvania. In addition to a survey of domestic water supplies at this site, five specially constructed monitoring wells were tested. The shallow monitoring wells suffered drops in water level due to mining but totally recovered within one day to three weeks after dewatering occurred. However, they did occasionally exhibit partial collapse during mine subsidence. Subsidence fracturing was beneficial in increasing the lateral hydraulic conductivity by a factor of about S to 22 for rock strata located within 124 feet of the surface, indicating enhanced shallow aquifer potential. One deep well suffered both partial dewatering and structural damage, with the state of water recovery bring uncertain. Also, two shallow domestic supplies out of five located over the mine were reportedly dewatered, but this claim could not, be substantiated.

Jan 1, 1988

By W. H. Eddy

The Bureau of Mines conducted laboratory batch and continuous flotation processing tests on waste granite fines from South Carolina to determine the possibility of recovering high-quality feldspar and glass sand. Three flotation systems were used for removal of the iron-bearing biotite: Two employed an alkaline anionic-cationic circuit and the third employed an acid cationic circuit. Commercial-grade products were obtained when the remaining biotite was magnetically removed from the feldspar and quartz concentrates. Continuous flotation processing yielded a feldspar concentrate containing, in percent, 3.60 Na20, 5.60 K20, and 2.25 Ca0, with recoveries of 75.3, 66.6, and 72.6 percent, respectively. The feldspar tailing was high quality glass sand containing 98.0 percent Si02 and 0.025 percent Fe203; about 60 percent of the quartz was recovered.

Jan 1, 1972

By R. L. Solmer

During 1959-61, the Bureau of Mines investigated the strain and deformation induced in rock and concrete linings around mine openings by retreat panel caving at the Climax Molybdenum mine. Two concrete-lined slusher drifts on the Phillipson level of the mine were instrumented with both electrical strain gages and extensometers. Changes in strain and deformation were recorded over an 18-month period during the undercutting and caving of the mining panel. General agreement was found between the strain and deformation measurements and the hypothesis that the vertical component of the stress field on the openings is almost completely removed by undercutting. This phenomenon is a possible explanation for the structural failures that occur in the slusher drifts during the undercutting cycle.

Jan 1, 1965

PUGET SOUND SECTION SIMON H. ASH, Chairman, I. F. LAUCKS, Vice-Chairman, CHARLES SIMENSTAD, Sec.-Treas., 425 Lyon Building, Seattle, Wash. GLENVILLE A. COLLINS, JOHN N. POTT. The Puget Sound Section met at the Arctic Club, Oct. 28, 1916, for the annual meeting. Those present were: Chairman Glenville A. Collins, Vice-Chairman H. L. Manley, Sec.-Treas. Amos Slater, Chester F. Lee, R. P. Tarr, G. E. Rockefeller, Simon Ash, Geo. W. Evans, Joseph Daniels, I. F. Laucks, F. C. Greene, Darsie C. Bard, Marcel Daly, Milnor Roberts, F. A. Hill, Percy E. Wright, and as guest, Mr. Coates of British Columbia. After dinner had been served, Chairman Collins called the meeting to order. The reading of the minutes of the last meeting were suspended upon request of the Secretary. The Secretary read the report from the Committee on the Associated Engineering Societies of Seattle. Upon motion, duly seconded, the report was adopted and placed on file. Mr. Lee, Chairman of the Committee. on the Mining Men's Convention to be held this coming winter, gave his report orally, and upon motion the committee was continued. The report of the Secretary-Treasurer was read, received, and placed on file.

Jan 3, 1917

By Rafael Flores

En los últimos años, el Perú ha crecido en términos de energía generada a través de los proyectos mineros y demanda vegetativa, donde se ha verificado un fuerte crecimiento en la zona norte y sur del país. En este sentido, el presente texto desarrolla un análisis del abastecimiento de la demanda del SEIN (Sistema Eléctrico Interconectado Nacional) en su conjunto, así como en los subsistemas centro, norte y sur, a través de la evaluación del crecimiento de la demanda y los nuevos proyectos de generación, considerando principios esenciales en la estructura de un funcionamiento adecuado de los sistemas interconectados.

Sep 14, 2009

By W. L. Goodwin

Twenty-five years ago mining engineering in Canada was not a profession. To-day the members of the mining fraternity can fairly claim for 10themselves the professional status. If their pretension is not fully warranted by fact it is not for lack of any technical attainment or service to the public but by reason merely of their neglect to cultivate the cohesion and consciousness that are the outward and visible signs of a professional body. This paper is an attempt, first to sketch briefly the course of the events during the past thirty-five years that have resulted in organizing the mining industry of this country in its present form; then to notice the principal features of the professional organization of this day; and finally to point out that an important part of the work of the mining engineer remains in the state of chaos that characterized the whole of it three or four decades ago, and to suggest a remedy. Thirty years ago there came a great wave of interest in mining in Canada, based principally upon the discovery of gold-quartz and gold-copper throughout wide areas in Nova Scotia, Ontario and British Columbia.

Jan 1, 1926

By H. A. Coy

THE Mascot mines of the American Zinc Co. of Tennessee are situated in the Holston River valley, in Knox County, Tennessee, about 13 miles (20.9 km.) east of the city of Knoxville, and form a property of three operating shafts and one open pit. A second open pit is located at Jefferson City about 16 miles (25.8 km.) east of the Mascot mines. Geology Topography.-The principal topographical features of the region within which the zinc deposits occur is a series of parallel northeast and. southwest ridges which reach altitudes of 200 to 400 ft. (61 to 122 m.) above the valley. These ridges are formed of resistant formation such as sandstone, quartzites, etc., while the valleys are occupied principally by limestone, including Knox dolomite, and by shale and other formations subject to quick erosion. The Holston River valley is wide and open with a rolling surface. Sink holes are common to the limestone portion, the general aspect of the valley being that of well-rounded hills with low intervening valleys superimposed upon which is a characteristic sink-hole topography. General Geology.-According to Keith, the rock formation of the area extends from the lower Cambrian into the Silurian. The region has undergone severe deformation with heavy faulting, the underlying Cambrian having been brought to the surface by a series of low angle thrust faults, the strike of the faults and formations paralleling the general northeast and southwest direction of the topography and clipping at varying angles to the southeast. In general the Cambrian quartzites, sandstone, etc., occupy the ridges while the Cambro-Silurian dolomites, limestone and shales occur principally in the valleys. Of the latter, the Knox dolomite is of particular interest to this paper in that it is the ore carrier in the Mascot area. The ore is associated with more or less irregular breccia zones, the degree of brecciation varying from-a fine crushing to a breaking that involves blocks of large size. The breccia zones

Jan 9, 1917

By Frank Nicholson

Copper ore was first noticed in Ste. Genevieve County in 1563. The diswvery mas made by a German farmer named Simon Grass, who had occasion to make a road from his farm down the hill into the neighboring valley, and while so engaged noticed pieces of a green-colored mineral, some of which he collected. Not knowing the character of the ore he had found, and supposing it to be valua ble for its brilliant green color only, he carried a piece with him into the town of Ste. Genevieve and showed it around the various bar rooms as a curiosity. No special attention was paid to the matter until nine years later, when Mr. 0. D. Harris sent a specimen of the ore to Dr. Theodore Fay, of St. Louis, for analysis. This analysis, which was the first ever made of Ste. Genevieve copper ore, showed the specimen to contain : Copper,. .........17.75 per cent. Zinc,..........3.21 " Iron........... 24.50 " Sulphur ..........1.09 " Organic matter, silica, carbon, and oxygen,. .. 53.45 " 100.00 " From this analysis it is evident that the sample was taken from near the surface, and was probably recognized by its green color. The almost entire absence of sulphur proves it to be an oxidized form. There is on file, at the office of the Ste. Genevieve Copper Works, a paper* giving three arsays of the ore made in 1875 by Henry B.

Jan 1, 1882

By E. H. Skinner

An abandoned mine shaft near Omar, in Logan County, W, was permanently sealed through a cooperative agreement between the West Virginia Department of Commerce, Labor, and Environmental Resources, Division of Environmental Protection, and the US. Bureau of Mines (USBM), Abandoned Mine Lands (AML) Program. An engineered shaft seal design was developed and demonstrated that featured lightweight concrete as a key material component at a wet density of about 45 lb/ft3. A reinforced concrete cap designed for 5 psi live load was placed over the shaft seal. Applicable new concrete technologies relating to a 100-yr design life were utilized to assure future integrity of the shaft seal. Waterproofing methods were included in the shaft seal design to provide protection from ambient moisture and corrosive mine waters and to increase the long-term durability of the shaft seal. All construction methods used in the field trial are fully adaptable for the mine-reclamation contractor, The USBM research objectives were to develop a broad generic design that will be widely applicable to other adit-sealing and shaft-sealing problems throughout the mining industry.

Jan 1, 2010

By P. M. Krishna

A five-year effort by the ASTM subcommittee E10.14 on Uranium Resource Evaluation has culminated in the approval of E901-82, Classification System for Uranium Resources. The standard classification was prepared with participation of representatives from the Dept. of Energy, the Dept. of Interior's Geological Survey and Bureau of Mines, utilities, and consultants. The classification of a resource is based on level of knowledge and the economic producibility of the resource at a given time. Alpha-numeric identifiers are used rather than words to avoid confusion with existing terms, definitions, and classifications. An effort is underway to develop estimation criteria to guide users in classifying a resource according to the above format.

Jan 1, 1983

By W. A. Tiller, W. C. Johnston

The solute distribution ahead of an advancing solid-liquid interface is controlled by varying the momentum boundary layer thickness in the liquid adjacent to the interface. Single pass zone-melting experiments on Pb-Sn alloys are described in which the liquid is caused to rotate in the plane of the solid-liquid interface due to the influence of a magnetic .field rotating in this plane. The variation of the diffusion boundary layer thickness with field strength is determined. DURING the freezing of an alloy a partitioning of solute occurs at the solid-liquid interface, the magnitude depending upon the difference in the solid and liquid solubilities at the interface temperature. Because the diffusion coefficient is so small in the liquid relative to normal freezing rates, either a pileup or a depletion of solute occurs at the interface when the partition coefficient, kO, is either less than or greater than unity, respectively. This solute distribution is completely characterized by i) the solute concentration in the liquid far from the interface, C) the ratio of freezing velocityf, to diffusion coefficient, D, iii) the partition coefficient, ko, and iv) the thickness of the diffusion boundary layer, 6,, at the interface (this assumes that an electric field is not applied across the interface). For a particular system, C ko and D are fixed so that the character of the solute distribution can be changed only by a variation of either f or 6c. As is well known, the freezing velocity can be changed by varying the thermal environment of the alloy. Whereas, the thickness of the solute rich layer can be changed by varying the fluid flow conditions in the liquid. It is the purpose of this paper to describe a technique for controlling the fluid flow conditions in the liquid. During most solidification experiments the driving force for fluid flow arises from either mechanical mixing, thermal convection or electromagnetic mixing. The momentum boundary layer thickness, 6m at the solid-liquid interface, within which negligible movement of the liquid occurs, has been calculated for the special case of mechanical mixing where crystals are solidified by the Czochralski technique.l,2 The calculation of 6m for the case of thermal convection has also been made.3 In some calculations it has been assumed that the momentum boundary layer thickness, 6,, may be equated to the thickness of the diffusion boundary layer 6c, at the interface. However, as may be seen from Appendix I this is only true in very special cases and in general where a is a constant of magnitude determined by the particular liquid alloy. Neither calculations nor experimental data exist for the dependence of upon electromagnetic mixing. In this paper experiments are described in which the liquid is caused to rotate in the plane of the interface due to the torque developed on it by a magnetic field, H, rotating in this plane. The variation of is controlled by the variation of H. A magnetic field rotating in a plane perpendicular to the interface has been used for the purification of aluminum. Experimentally, we determined the variation of 5C with H by using the zone-melting technique of pfann5and a theoretical relationship of Burton et a1.2 pfann5 has shown that, after the passage of one molten zone through a long cylindrical charge of uniform concentration, CO, the solute distribution, C,, in the solid is as shown in Fig. 1. The equation describing this distribution is

Jan 1, 1962

During the past decade geopolymer technology has emerged as a possible solution for the effective stabilisation and solidification of waste materials. Amorphous to semi-crystalline geopolymers form by the co-polymerisation of individual alumino and silicate species, which originate from the dissolution of silicon and aluminium containing source materials at a high pH in the presence of soluble alkali metal silicates. It has been shown previously that geopolymerisation can transform a wide range of waste alumino-silicate materials such as fly ash and blast furnace slag into building and mining products with excellent chemical and physical properties, including high compressive strength as well as fire and acid resistance. These chemical and physical properties suggest that geopolymeric matrices derived from waste materials are well suited for environmental and other applications such as the encapsulation of mine tails, the immobilisation of heavy metals and also the fabrication of structural products. The current challenge is to demonstrate that a wide variety of natural Al-Si minerals could serve as potential source materials for the synthesis of geopolymers. Moreover, it should be shown on a large commercial scale that it is possible to encapsulate waste materials into the geopolymeric structure without compromising the chemical and physical properties of the final product for the desired application.

Jan 1, 2000

OFFICERS AND DIRECTORS For the year ending February, 1932 PRESIDENT ROBERT E. TALLY JEROME, ARIZ. FREDERICK W. BRADLEY SAN FRANCISCO, CAL. WILLIAM H. BASSETT,P WATERBURY, CONN KARL EILERS NEW YORK N. Y.

Jan 1, 1929

By M. Rossi

The use of service variables in geostatistics (grade-thickness) is common in industry when developing block grade models and geologic resource estimates. This is particularly true in the case of sedimentary and stratabound-type deposits. The approach has proven merits when assessing ore reserves. However, there are cases where its application for preliminary data analysis produces biased estimates. One such case is encountered in uranium disequilibrium studies. This paper demonstrates the inadequacy of service variables when performing uranium disequilibrium studies. Disequilibrium analysis is a necessary preprocessing step when radiation counts are used as raw data to calculate uranium reserves. Typically, a probe is used to obtain the gamma counts from open drill holes. These counts are then regressed (and corrected) against chemical assays obtained from core samples. During this process the grade-thickness variable produces an optimistic image of the relationship between probe grades and chemical (true) grades, causing overestimation of the final geologic resource. The problem is analyzed through a case study.

Jan 1, 1993

Provide an accurate, reliable means for determining when a sealed mine or mine section can be safely reopened after a fire. Approach The Bureau of Mines performed a research investigation that resulted in the development of a mathematical formula for deriving a quantity, called RATIO, which can be used to define when a sealed mine or mine section has returned to safe recovery conditions after a fire. Research Results There were two major results from this Bureau research. Over a period of several years, the Bureau of Mines conducted six experiments at its Bruceton Experimental Mine in Pennsylvania. The experiments involved sealing the mine after several tons of piled coal had been allowed to burn continuously for 2 to 3 days. Although gas data obtained during the experiments revealed nothing significant, measured smoke particle levels were found to correlate with the stages of combustion and temperatures of the smoldering coal pile. Moreover, it was found that no smoke particles are produced when high-temperature smoldering exists deep within the mass of the coal pile since the smoke particles are filtered by the coal surrounding the hot region. Smoke is emitted into the mine atmosphere only if combustion is occurring near exposed surfaces. As suggested by these findings, any decision to recover a sealed mine area based primarily upon the absence of smoke particles is not a wise derision.

Jan 1, 1988

By Kiyoshi Azuma, Hiroshi Kametani

Dissolution of a ferric oxide in acid solution is divided into two different types In the accelerated type dissolution proceeds in three stages 1) an inittal reaction during which the dissolved amount of oxide is nearly proportional to the cube root of time ; 2) an accelerated reaction: and 3) a final stage during which dissolution approaches completion. This course of dissolution gives an S-shaped curve in the above sequence OH a log weight percent of dissolved oxide against log time graph. In the parabolic type dissolution proceeds in four stages: first and second stages similar to those of the accelerated type; 3) parabolic-rate dissolution during which the dissolved amount of oxide is nearly proportional to the square root of time: and 4) a final stage. The effect of the kind of acid, the temperature of solution, and the concentration of acid was investigated. The results are discussed and a rate equation is proposed. AN attempt has been made to obtain some information on dissolution of a ferric oxide in various acid solutions. In view of hydrometallurgical processes the dissolution of ferric oxide is of less importance than that of zinc oxide or copper oxide in general. One of a few processes which intend to dissolve ferric oxide is an elimination of iron impurity from acid-insoluble materials. However, most leaching processes of oxide ores and cinders are accompanied with more or less dissolution of iron. According to Pryor and Evans1 the rate of dissolution of a ferric oxide in various acids decreased in the order of hydrofluoric acid > hydrochloric acid > sulfuric acid > perchloric acid. This order was in accord with the order of decrease of the complexing affinity of the anion for ferric ion,

Jan 1, 1964

By R. S. Krarner

Fly ash, a by-product of coal burning power plants, poses a major problem for the utility industry since most fly ash must be landfilled. These quantities may represent as much as 20% of the total material going into landfills. A major problem with fly ash utilization is that although the ash consists of useable components, ash composition can vary depending on the types of coal burned and plant operating conditions. Ash is first characterized using SEM, image analysis, and chemical methods. Processing techniques were developed to separate ash into various components including cenospheres, magnetic spheres, carbon, and clean ash. These products are again evaluated for various utilizations before being used to produce valuable products such as mullite, activated carbon, fillers in plastics, and concrete.

Jan 1, 1994

In this study, numerical simulations of yield pillars employing the finite element method with time-dependent Drucker-Prager material model are conducted. The stress control mechanism of yield pillars on weak floor strata is studied. The development of pillar yield zone, the distribution of pillar stress and the development of failure zone in the weak floor strata are investigated. The study indicates that a properly selected yield pillar size may significantly reduce the peak stress induced in the weak floor strata and effectively control the development of failure zone in the floor.

Jan 1, 1999