Search Documents

By J. H. Jackson, J. G. Kura, M. C. Udy, L. W. Eastwood

The melting and casting of any commercial metal depends upon the success with which the problems attendant to the handling of the specific metal are overcome. Common difficulties encountered in the handling of commercial metals are tendencies to burn or oxidize excessively, low fluidity, entrapment of dross, hot cracking, cold embrittlement, cold shuts, and un-soundness caused by gas evolution. Beryllium is not only subject to these same difficulties but is generally more sensitive to them than are the more common metals, thus necessitating more exact founding precautions. Characteristics of Beryllium Certain characteristics of beryllium which make it particularly difficult to handle in the plant or laboratory are as follows: 1. The melting point of beryllium is about 2400°F and pouring temperatures vary from 2600 to 2900°F, depending upon the degree of fluidity required. The extreme chemical activity, combined with the high temperatures, makes necessary the use of inert atmospheres, slags, or vacuum for protection during melting and pouring. Furthermore, beryllium tends to react with the melting crucibles, tools, and molds, thus requiring the selection of suitable materials and proper maintenance of these items. 2. The very marked absorption of gas by molten beryllium and the subsequent evolution of gas during solidification causes a great deal of difficulty with unsoundness. Beryllium castings may also be subject to unsoundness as a result of gas formation by chemical reaction with the mold surface during solidification. 3. The very marked chemical affinity between molten beryllium and the normal atmosphere causes the formation of dross. On relatively quiescent melts, this dross forms a very tenacious film which, if carried over to the mold, can cause defects such as the formation of skins or dross in the interior or on the surface of the casting; folds or defects similar to cold shuts may also be found. 4. During the pour and attendant turbulence, the dross may be mixed into the metal and then carried to the casting. There it may be entrapped during freezing and cause internal defects, or it may float to the surface and cause severe dross defects on the cope side of the castings. 5. Solid beryllium is very weak at a temperature near the solidus line; brittleness is also a problem at lower temperatures. Thus, hot and cold cracking must be guarded against. Scope of the Experimental Work All of these problems have been given consideration in the work at Battelle. Before the work was started at Battelle, it was customary to melt beryllium in a vacuum furnace or under flux in graphite-lined induction furnaces. Because of the difficulty of preventing gas unsoundness in beryllium castings, an investigation was undertaken primarily to study this particular problem and, secondarily, to devise methods of overcoming the other difficulties encountered in the founding of beryllium. The objectives of the laboratory work were multifold: 1. To devise a practical method of melting, other than vacuum melting, by means of which consistently sound beryllium castings could be produced. 2. To obtain fundamental data which would promote a better understanding of the causes of gas unsoundness in beryllium. 3. To develop a casting technique which would permit low melt temperatures, minimize dross defects and hot cracking, and eliminate reaction with the mold surface. Up to the present time, a considerable amount of progress has been made on the first and third objectives, with the result that it can now be safely stated that consistently sound castings can be made by the open-pot melting method, using argon as a protective atmosphere and a proper casting technique. There has been some progress on the second objective of the project, but it cannot yet be safely stated that the problem is completely understood. Most of the experimental work has been conducted in an enclosed melting and pouring apparatus in which very-close control of melting variables has been effected. Findings based on the results of the work conducted in this small experimental apparatus have been applied to large-scale melts which have been made by techniques suitable for duplication on a commercial scale.

Jan 1, 1950

By W. C. Lilliendahl, G. Meister

Uranium metal with a purity of about 99.9 pct was produced on a large scale by fused salt electrolysis with a material efficiency of about 90 pct. The material efficiency depends mainly on bath composition, electrolysis temperature, electrode smothering, and elutriation during washing of the powder. RESEARCH and development work on fused salt electrolysis carried on by the Westinghouse Lamp Div. Bloomfield, N. J., was done under the Manhattan District Corps of Engineers and later under the Atomic Energy Commission for the commercialization of uranium production for the first atomic pile at the University of Chicago in 1942. From the conception of the atomic bomb project it was recognized that metals with impurity levels having little metallurgical significance would be required. Permissible impurity levels were based on neutron absorption. Of particular significance was boron, which could not be present in amounts exceeding 1 ppm. The electrolytic method as developed in 1930 by Driggs and Lilliendahl,1,2 and later improved, yielded uranium of very low boron and other deleterious impurity content. No other method was capable at that time of producing uranium metal of the required purity.' The low boron content of uranium produced by the electrolytic process resulted from the availability of the reactants which were low in boron content, and from the inherent elimination of boron in the fused salt bath. Since the heart of any electrolytic process is the electrolysis cell, this paper will deal with the development of the original bath composition for the efficient production of uranium from a batch process to one of continuous operation. Emphasis also will be placed on other factors which will affect the material efficiency of the process. With the laboratory cell the material efficiency of uranium powder recovery in the early electrolysis was relatively low, about 35 pct based on the ratio of uranium recovered to uranium added. This early process also had other defects. The electro- lytic bath could not be used continuously. After three runs from a freshly charged crucible, the deposit showed a tendency to slip off the electrode as it was raised from the bath. This condition necessitated pouring the charge every fourth run and preparing a new bath. It was assumed at that time that this condition was caused by the increasing fluoride concentration with each addition of uranium salt, which adected the mobility of the uranium ions. Experimental The electrolysis cells differed in size only. They were of the floating cathode type. The laboratory cells were 21/2 in. ID and 6 in. deep and operated at 30 amp and 5 volts. Production was about 150 g metal powder per 8 hr. The plant cells (5 units) were 9 in. ID x 21 in. deep and operated at 1800 amp at 12 volts. The total production unit was designed to produce 250 lb of uranium powder per 8 hr day. Because of the tendency of uranium fines toward spontaneous combustion, material efficiencies were based only on the recovery of useful coarser metal which could be safely handled. The reported efficiencies are of particular significance only as related to the same group of experimental procedures. At the start of the project no changes were contemplated until previous data could be definitely confirmed. Therefore, the first experiments were with the 50 pct CaCl2-50 pct NaCl mixture. The material efficiency of uranium deposition as a function of the number of electrolyses is shown in Table I. In Table I, the decrease in efficiency at 800°C with number of runs is apparent and confirmed the earlier data. Operating at 900°C enabled the number of runs to be doubled, but before pouring the charge the efficiency of recovery became poor. This test indicated that the improved efficiency might have been caused by an increase in the fluidity of the bath.

Jan 1, 1958

By M. D. Hassialis

THE object of a technical paper is to communicate new technical knowledge, the paper being the vehicle of communication and the existence of new knowledge its reason for being. It follows that the development of information worthy of communication, the criterion being novelty, is prerequisite to exercising the privilege of communication. The act of communication is achieved when the reader perceives the nature of the new knowledge, i.e., when he understands it. A paper achieving this objective is an acceptable technical paper. Development of new knowledge has as one of its purposes the increase of the existing state of knowledge and the enjoyment of the benefits derived therefrom. Technical knowledge is a collection of facts so ordered as to make apparent, relations existing between the facts. When the interrelations have been exposed the facts have been interpreted or explained Three broad, overlapping categories of technical papers may be recognized: papers consisting of (a) a report of facts, (b) an explanation of facts, or (c) a combination of a report and an interpretation. Ideally a technical paper should belong to one of the last two categories but current practice is to accept papers belonging to any of the three categories. Based on a small sample drawn from the scientific and engineering literature, the relative frequency of the three types is a: b: c:: 20:1:14. If the sample be limited to engineering literature, the ratios become a:c::2:1; type (b) being nonexistent. This large departure from the ideal is a consequent of the

Jan 1, 1948

COUNCIL OF SECTION DELEGATES A J Duff G H Ruggles E D Gardner E H Torgersen F W Strandberg, Chairman W I Garms H C Weed R D Chapman, Vice-Chairman H M Lavender J A Wilcox F T Moyer. Secretary W C Lawson C F Willis EXECUTIVE COMMITTEE J E Kastrop L Thiessen Past Chairmen R H Smith E H Wisser P D I Honeyman R W Hughes C H Kuzell

Jan 1, 1951

By J. F. Smith, J. E. Davison

A value for the enthalpy of formation of z2 of -3.14 i 0.21 kcal per g-atom has been measured by the technique of acid solution calorimetry. This result is in quite good agreement with two earlier determinations by tin solution calorimetry and by direct reaction caloriinetry, and averaging of values determined from the three independent calorimetric techniques gives enhanced precision and accuracy with AHh8 (CaMgZ) = - 3.15 i 0.05 kcal per g-atom. For comparison with experimental data, values for the enthalpies of formation of CaMgz, SrMgz, and BaMgz of -9.8, -7.9, and -2.8 kcal per g-atom were estimated from a calculation based on the LVigizer-Seitz approximation as modified by Raimes for polyvalent elements. While complete quantitative accord between these calculated talues and available experimental data is lacking, nonetheless numerical accord is better than might be expected and, more importantly, parallel numerical trends are observed between experimental and calculated vnlues. WITHIN the past decade the enthalpy of formation of CaMg, has been determined a) from measurement of magnesium vapor pressures over binary Ca-Mg alloys,' b) by solution calorimetry with liquid tin as the solvent,' c) from measurement of hydrogen vapor pressures over ternary alloys of calcium, magnesium, and hydrogen,3 and d) by direct reaction alorimetr. The value from tin solution calorimetry is the most precise and is probably the most reliable, and this value is within the quoted uncertainties of the other three experimental results. The overall agreement among the four independent investigations is quite good, particularly so when the diversity of techniques is noted. On the basis of this agreement, CaMgz was chosen as a test material to evaluate the operation of a newly constructed apparatus for the determination of enthalpies of formation of intermetallic phases by acid solution calorimetry. This was believed to be a severe test because of the high chemical reactivity of both calcium and magnesium which reactivity presumably accounts for the fact that an early determination5 of the enthalpies of formation of Ca-Mg alloys by acid solution calorimetry yielded values significantly more negative than the four recent determinations. EXPERIMENTAL APPARATUS AND MATERIALS Experimental Apparatus. The enthalpy of formation of CaMg, was determined by measuring the difference between the heat evolved when dissolving the metallic compound and the heat evolved when dissolving equivalent amounts of unreacted metallic elements in hydro- chloric acid. This was done differentially with an apparatus consisting of twin calorimeters which were constructed to be as nearly identical as possible. The advantage of differential calorimetry is that systematic errors arising from the individual calorimeter design tend to cancel. A schematic representation of the apparatus is shown in Fig. 1. A dead air space around both calorimeters was provided by a large, thermally insulated jacket. Each calorimeter consisted of a 2-liter Dewar flask which was completely enclosed in a copper container. Each Dewar contained 1600 g of 2.5hr HCl to act as the solvent, and thermal effects resulting from solvent evaporation were minimized by covering the acid with 50 g of mineral oil. There was no detectable reaction between the acid and the mineral oil. Equivalent amounts of mechanical energy were added to the calorimeters through twin stirring rods which were driven at the same rpm by a single motor with the intent of the stirring being to maintain thermal equilibrium throughout the solvent. To calibrate the heat capacities of the calorimeters, known amounts of electrical energy could be added by passing measured voltages and currents for known times through submerged heaters, approximately 20 ohms, which were wound noninductively from Manganin wire. A 6-v storage battery was used as a power source, and a dummy heater was used as an exercise circuit to allow the battery to stabilize at a constant electromotive force before energizing one or the other of the calorimetric heaters. A type K-2 potentiometer was used to measure the potential drop across an energized heater while the current was determined from the potential drop across an external standard resistor. Times of energization were measured with an electric timer, and the electrical energy supplied to a heater

Jan 1, 1969

By Charles T. Van Winkle

Until the advent of the porphyry coppers and the introduction of flotation which soon followed, crushing and grinding for many years proceeded along somewhat stereotyped lines, without important alteration in type of machinery. For the finer crushing and grinding, stamps, rolls, and various patterns of Huntington and Chilean mills were in general use. Ball-mills were in use abroad, but owing to their small capacity and the high cost of screens and steel, they never obtained much footing in the United States. Tube-mills were first introduced into the crushing departments of cyanide plants when it was found that for crushing finer than 30-mesh other types of crushing machinery were not efficient. In order to crush with one pass, these mills were made 18 to 22 ft. (5.5 to 6.7 m.) in length. Pebbles were used as a grinding medium and the mills were lined with either silex blocks or fragments of quartz or flint pebbles set in cement. While the cylindrical tube pebble-mill had been used to some extent in small installations of concentration mills, the first instance of its use on a large scale was at the concentrating plant of the Miami Copper Co., where 8-ft. by 22-in. (2.5-m. by 55.9-cm.) Hardinge mills were tried out against Chileans. The results of these experiments led to the gradual replacement of the Chilean by the Hardinge mill. Robert Franke published an article' describing the work done, comparing the two types of mills. At the same time, according to Franke, a test was run using a 6-ft. (1.8-m.) Hardinge ball-mill as a substitute for rolls for intermediate crushing on 1/2-in. material. According to Franke, this mill was soon discarded, since it was found that to obtain the desired product the mill must be limited in capacity. The Miami Copper Co. made no test with other types of ball- or pebble-mills. Following this example, others installed the conical type; and when the Inspiration Consolidated Copper Co. decided to build a concentrator, it adopted the conical mill. As the requirements for mills would be very large, it purchased manufacturing rights in the State of Arizona from the

Jan 1, 1918

By Brian F. Osborne

A continuous on-line particle-size analysis system for solid/liquid suspensions is described. The basic sensor utilizes a centrifugal principle to separate particles according to size, the resultant separation being measured by means of beta-ray attenuation. Results obtained when analyzing a variety of materials at sizes from 65 mesh (210 µ) to 20 w are discussed in detail. Accuracies better than 2% are demonstrated. The effects of particle specific gravity, and mixtures of materials of diverse specific gravities, are discussed from both a practical and a theoretical viewpoint. It is demonstrated that particle specific gravity has a minimal effect on the size reading obtained. This renders the instrument suitable for handling materials where the ratio of light to heavy component may change. The design of the first commercial installation of this instrument is described in detail. This installation will be capable of analyzing three streams in sequence, measurement at three particle sizes being effected on each stream.

Jan 1, 1975

SOUTHERN CALIFORNIA SECTION Executive Committee SEELEY W. MUDD, Chairman. C. COLCOCK JONES, Vice-Chairman. FREDERICK J. H. MERRILL, Secretary-Treasurer, 631 Higgins. Bldg., Los Angeles, Cal. RALPH ARNOLD A. B. CARPENTER A. B. W. HODGES WILLIAM F. STAUNTON The third meeting of this winter season tool: place in a private dining room of the Sierra Madre Club in Los Angeles on Feb. 1, 1916, at 6:30 p.m., 22 members and guests being present. In the absence of the Chairman, S. W. Mudd, the Vice-Chairman, C. Colcock Jones, presided. After an enjoyable dinner the meeting was called to order, and the first paper by Ralph Arnold on Conservation of Oil and Gas in the Americas was read by the Secretary. W. F. Staunton then read an important paper on The Influence of California Oil on the Mining Industry of the West. In this he touched upon the uses of oil as a fuel for generating power, especially in connection with the Diesel engine. This paper was discussed it some length by J. F. Mitchell-Roberts, R. B. Moran, F. H. Asbury and L. D. Godshall. The Chair then introduced Robert B. Moran of the California State Mining Bureau, Deputy Supervisor of Gas and Oil, for the' Los Angeles . District, who addressed the meeting on the work of his department. The meeting concluded with A. B. Carpenter's reading of a paper on The California Gasoline Industry by W. R.. Hamilton, Manager of the Ventura Refining Co. F. J. H. MERRILL, Secretary. ,

Jan 4, 1916

By David White

THE submission of carefully prepared estimates of the oil reserves of the United States calls for no apology or explanation. In this country, petroleum is a rapidly wasting asset and an occasional appraisal of the amount remaining in the ground is a simple business procedure to safe-guard the general welfare and the prosperity of the republic. The rumored danger of failure, in the near future, of the foreign supply on which we depend in constantly increasing amounts makes the immediate review of our available reserves the more imperative. The Director of the U. S. Geological Survey, in March, 1921, requested the American Association of Petroleum Geologists to cooperate in the preparation of new estimates of the oil remaining in the ground. With the members of this cooperative committee, state geologists, regional geologists, consulting specialists, and geologists and engineers attached to many companies worked both independently and through sub-committees. The reports for districts, counties, fields, etc., after review by local or state committees, were discussed by the joint cooperative committee in conferences that, in some instances, were attended by the original compilers of estimates for the states or smaller areas. Finally the data were reviewed and the figures revised by the joint cooperative committee, so that the totals given in Table 1 represent the opinion of the committee, which was composed of F. W. DeWolf, W. E. Wrather, Roswell H. Johnson, Wallace A. Pratt, Alexander W. McCoy, Carl H. Beal, C. T. Lupton, G. C. Matson, K. C. Heald, W. T. Thom, Jr., A. E. Fath, Kirtley F. Mather, R. C. Moore, and David White, chairman.

Jan 6, 1922

By A. J. May

THE Star shaft is near the north boundary of the group of mining claims belonging to the Ground Hog Unit of the American Smelting and Refining Co., near Vanadium, N. Mex. The shaft bins and surface plant are served by a siding from the Atchison, Topeka and Santa Fe railroad, and this factor of railroad transportation influenced the choice of site. This paper describes the shaft sinking only, and does not cover the surface plant or other parts of the mine or its equipment. A. J. MAY is Engineer in Charge of Shaft Sinking, Ground Hog Unit, American Smeling and Refining Co, Vanadium, New Mexico. El Paso Meeting, October 1948. TP 2737 A. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Nov. 29, 1948; revision received June 22, 1949. Experience with this shaft seems of interest because of the mechanical mucking, good rate of progress, and the costs obtained at the present level of labor and material costs. The shaft has four compartments, as shown in fig. 1. Equipment: Riddell Mucker: The mucking was done by a clamshell bucket and a Riddell mucker, which, as in other shafts sunk with this machine, consisted of a carriage mounted on axles with double flanged wheels that traveled back and forth on a swinging track, parallel to the long axis of the shaft (fig. 2 to 6). Three air motors were mounted on the carriage; one hoisted the clam, one operated the bucket opening and closing device, and the third moved the carriage along the track. The carriage was designed with guide shoes and could be hoisted to the surface in either skip compartment without trouble (fig. 4). During blasting operations the clam was tied on the rails and the carriage was hoisted up a few sets to protect it from flying rock. No attempt was made to hoist the carriage and clam together lest the clam catch in the timbers. The track on which the carriage operated was built of extra heavy 6 in. pipe with 1x2 in. strap welded on top for rails. A Yzx4 in. angle was welded on the bottom of the 6 in. pipe with a 1 in. round rod welded in the angle for a filler and additional strength. The end or cross pieces of the track which kept the track to gauge, were also made of reinforced, heavy 6 in. pipe and were bolted to the long members on which the carriage traveled (fig. 2 and 3). This section of track was used, instead of heavy railroad rails, for two reasons: (1) this section would bend before it snapped and was much safer for the men in the bottom; and (2) it was a better blasting shield, and protected the timbers better, in fact, only five wall plates were broken by blasting in 1926 ft of shaft, although 150 to 225 lb of 40 pct powder was loaded per round, depending on the ground conditions. The swinging track was supported by four % in. hoisting cables anchored to the end plates. There were also four safety cables fastened two to three sets above the carriage, which would catch the carriage if one of the supporting cables should fail for any reason (fig. 7). Clamshell Buckets: Two clams were used, each of % yard capacity, both manufactured by Blaw-Knox, Nos. 662 and 663. The No. 663 clam was 4 in. wider and 5 in. shorter than the No. 662, but seemed to dig and load more satisfactorily. It was easier to hoist and lower when it came up for repair. It did not turn over as easily, had less spill

Jan 1, 1951

By A. J. May

THE Star shaft is near the north boundary of the group of mining claims belonging to the Ground Hog Unit of the American Smelting and Refining Co., near Vanadium, N. Mex. The shaft bins and surface plant are served by a siding from the Atchison, Topeka and Santa Fe railroad, and this factor of railroad transportation influenced the choice of site. This paper describes the shaft sinking only, and does not cover the surface plant or other parts of the mine or its equipment. A. J. MAY is Engineer in Charge of Shaft Sinking, Ground Hog Unit, American Smeling and Refining Co, Vanadium, New Mexico. El Paso Meeting, October 1948. TP 2737 A. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Nov. 29, 1948; revision received June 22, 1949. Experience with this shaft seems of interest because of the mechanical mucking, good rate of progress, and the costs obtained at the present level of labor and material costs. The shaft has four compartments, as shown in fig. 1. Equipment: Riddell Mucker: The mucking was done by a clamshell bucket and a Riddell mucker, which, as in other shafts sunk with this machine, consisted of a carriage mounted on axles with double flanged wheels that traveled back and forth on a swinging track, parallel to the long axis of the shaft (fig. 2 to 6). Three air motors were mounted on the carriage; one hoisted the clam, one operated the bucket opening and closing device, and the third moved the carriage along the track. The carriage was designed with guide shoes and could be hoisted to the surface in either skip compartment without trouble (fig. 4). During blasting operations the clam was tied on the rails and the carriage was hoisted up a few sets to protect it from flying rock. No attempt was made to hoist the carriage and clam together lest the clam catch in the timbers. The track on which the carriage operated was built of extra heavy 6 in. pipe with 1x2 in. strap welded on top for rails. A Yzx4 in. angle was welded on the bottom of the 6 in. pipe with a 1 in. round rod welded in the angle for a filler and additional strength. The end or cross pieces of the track which kept the track to gauge, were also made of reinforced, heavy 6 in. pipe and were bolted to the long members on which the carriage traveled (fig. 2 and 3). This section of track was used, instead of heavy railroad rails, for two reasons: (1) this section would bend before it snapped and was much safer for the men in the bottom; and (2) it was a better blasting shield, and protected the timbers better, in fact, only five wall plates were broken by blasting in 1926 ft of shaft, although 150 to 225 lb of 40 pct powder was loaded per round, depending on the ground conditions. The swinging track was supported by four % in. hoisting cables anchored to the end plates. There were also four safety cables fastened two to three sets above the carriage, which would catch the carriage if one of the supporting cables should fail for any reason (fig. 7). Clamshell Buckets: Two clams were used, each of % yard capacity, both manufactured by Blaw-Knox, Nos. 662 and 663. The No. 663 clam was 4 in. wider and 5 in. shorter than the No. 662, but seemed to dig and load more satisfactorily. It was easier to hoist and lower when it came up for repair. It did not turn over as easily, had less spill

Jan 1, 1951

By John K. Kennedy

ThE basic equations describing continuous zone-melting via the zone-void method were reported by Pfann. Using these equations, a theoretical study was undertaken in this laboratory on the effect of the variation of the significant parameters of the zone-void system. These parameters are the zone length, 1, the heater length, h, and the effective distribution coefficient, k. The object of this study was to determine the effect of these parameters on and (where a = Cp/Cf and ß = Cw/Cf, Cp, C,, and Cf being, respectively, the solute concentration in product, waste, and feed) so that, in future application of this technique to the ultrapurification of materials, the effect of 1 and h would be predictable regardless of the value of k. The basic assumptions made by pfannl were, for the purposes of this study, assumed to hold. For k < 1, the steady-state solute distribution in the stripping section and the shift in this distribution brought about by passage of a void is shown in Fig. 7 of Ref. 1. In this section the definition of k and ß precludes the possibility of ß assuming values less than unity when k < 1. In the course of this investigation it was found that computations based on Pfann&apos;s equations gave values of ß less than unity in the region 1 > k > l/h for almost all values of Ls, where Further computations showed that 6 assumes negative values when k > 1 for many values of L,, 1, and h. A check of the derivation of the stripping-section equations showed that an error had been

Jan 1, 1964

By R. M. Zimmerman

INTRODUCTION Tuff is being considered as a possible geologic median for the underground storage of commercial high level radioactive wastes by the Department of Energy (DOE). DOE has the responsibility for developing or improving the technology fir safely and permanently isolating these wastes. DOE programs must satisfy requirements established by the Nuclear Regulatory Commission (NRC) for the licensing and regulating of these storage facilities (NRC 1981). Pertinent draft NRC requirements are: 1) releases of radioactivity to the environment must be within prescribed limits and 2) emplaced canisters containing wastes must be retrievable up to 50 years following emplacement. High level radioactive wastes produce heat in storage and it is essential that the thermal/mechanical/hydrological response of the host rock will not significantly degrade either the structural performance o£ the repository or the ability of the natural or engineered barriers to retard radionuclide migration. The Nevada Nuclear Waste Storage Investigations (NNWSI) was established by DOE to evaluate the suitability of disposing of high level nuclear wastes on or near the Nevada Test Site (NTS) (NNWSI 1980). NNWSI has focused exploration and site evaluation on the tuffs of Yucca Mountain. Field testing is essential to support site characterization and repository design efforts. Preliminary studies have been conducted indicating that tuffs in G-tunnel on the NIS contain welded and nonwelded tuffs that have similar properties to those in Yucca Mountain. Thus, field testing can be accelerated. This paper discusses the issues supporting the planned field experiments in G-tunnel. Issues not related to rock mechanics are not included.

Jan 1, 1982

By C. W. Goodale

As an appendix to the above-mentioned paper, a drawing of the vertical projection of the Knoxville mine workings is here given. In my paper it was stated that the ore-chimneys are found along a crack or plane of cleavage in the limestone ; and as this crack is not parallel with the strata, it is safe to assume that the manganese was not deposited where it is now found before the tilting-up of the strata, but rather that the crack was caused by the folding, and that tile formation of the ore was entirely subsequent to the change of position of the limestone. There are here four chimneys, which have produced, as far as explored, over 12,000 tons of ore, containing at least 7000 tons of manganese oxides, and it is very difficult to apply Prof. W. P. Blake&apos;s theory of segregation from the surrounding limestone in accounting for the origin of this ore, as cross-cuts and drifts in the countryrock, even at short distances from the ore-chimneys, have not shown manganese in appreciable quantities. It is easier to believe that, in the language of .Mr. S. F. Emmons, in speaking of Leadville ore-deposits, there was a metasomatic interchange between the minerals brought in in solution and the limestone, and not a deposition in already existing cavities. This in-

Jan 1, 1890

By R. C. Hirschfeld, H. H. Einstein, R. W. Bruhn, R. A. Nelson

The objective of the model studies described in this paper is to determine the effect of planar discontinuities on the strength and deformability of a rock mass. A model material was used because it satisfied concurrently three requirements that available natural-rock samples did not: (1) low strength, which was desirable for minimizing the loads that had to be applied in the laboratory; (2) ease of producing test specimens with geometrically regular joint patterns; and (3) uniformity of the test specimens. The model tests were performed on specimens made from a single modeling material and tested under triaxial stress conditions with [u,=u,]. Results are presented in this paper for tests on specimens that had (1) a single joint set inclined at several angles to the major principal direction, including 0º and 90°, and (2) two joint sets that were mutually perpendicular, one set perpendicular to and one set parallel to the major principal direction. Several different joint spacings were used in each series. Future tests will include a series with two sets of joints that make oblique angles with each other and with the major principal direction. The results of model tests and tests on cores of jointed rock by several investigators (e.g., Müller and Pacher,l Moore,2 Krsmanovic and Milic,3 Hayashi,4 Rosenblad,5 Jaeger,6 and Lane and Heck 7, have contributed significantly to the design of these experiments, which are believed to be the first in which a comprehensive study has been made of the combined effects under triaxial loading of joint spacing and joint orientation (Fig. 1).

Jan 1, 1970

By WILLARD HAYES

(Glen Summit Meeting, June, 1911.) THE determination of the question whether the Mayari and Moa mining-claims of the Spanish-American Iron Co. have been rightly denounced under the third section of the law of bases rests on the findings in the following questions of fact: 1. Is the mineral an iron-ore? 2. Is the iron-ore a bog iron-ore? 3. Is the iron-ore ocher? 4. If ocher is present, can it be mined separately and independently of the iron-ore ? 1. IS THE MINERAL AN IRON-ORE? Since the material is shown by a large number of analyses to contain from 41. to 50 per cent. of metallic iron and less than 0.02 per cent. of phosphorus, and since it has been and is being actually used on a commercial scale for the production of iron and steel, it must be classed as an iron-ore. 2. IS THE IRON-ORE A BOG IRON-ORE? Bog iron-ore has certain invariable characteristics of chemical composition, physical appearance, geological relations, and origin by which it can always be recognized with certainty. In chemical composition, it is the hydrated sesquioxide of iron, limonite, or a mixture of limonite and other closely-related iron hydrates. It never contains the anhydrous oxides-hematite or magnetite; is never magnetic, and never contains either nickel, chromium, or cobalt oxides. On the other hand, it is invariably high in phosphorus-content. In physical appearance and texture it is a yellow or reddish-brown amorphous spongy material, and always contains water-worn sand-grains, silt, clay, and plant-remains. In its geological relations it is wholly independent of the rock

Mar 1, 1911

By Franklin Bache

There seems to be in the public mind, and even in the minds of some coal-operators not experienced in mines subject to dust-explosions, a feeling that there has been somet-hing mysterious at the bottom of a number of recent American colliery-exploaions. It has been declared in cases of accidents in mines regarded as particularly well equipped, in which every preventive precaution was said to have been taken, that the explosions were incomprehensible, and resulted from causes beyond the present knowledge of the practical coal-operator. But it is safe to say that no explosion has taken place which could not be explained by reasons well understood by most operators. The U. S. Geological Survey Testing Laboratory, recently inaugurated at Pittsburg for the reported purpose of investigating scientifically the matter of explosions in mines, will discover no new explanation of explosions. It can, however, co-ordinate the previous investigations of similar boards in England and on the Continent; and it may do a vast amount of good by promulgating widely, and in a form comprehensible to the most unlettered miner, certain facts and obvious deductions that cannot but have an effect in reducing the number and extent of the mine-disasters which, in the last few years, have been so terrible in frequency and magnitude.

Jan 1, 1910

By Utley Wedge

(Cleveland :Meeting, October, 1012.) In general, the art of securing copper from sulphide ores or concentrates may be said to consist of : (1) separation, in the molten state, of copper sulphide with some iron sulphide, from the great bulk of gangue-material, followed by (2) elimination of sulphur and iron from the molten matte, by oxidation and fluxing, leaving metallic copper. The definition is made broad enough to cover the general practice, whether or not the ore or concentrate is given a preliminary roast for the removal of surplus sulphur. The above process, which I will designate as the smelting process, makes necessary the presence in the ore, or the addition thereto, of such silica, lime, and iron as may be necessary for the formation of a light and fusible slag, together with sufficient sulphur and iron for the formation of copper-matte, and also the addition to the matte of sufficient silica for the oxidation and fluxing-out of the iron. These items, together with the cost of fuel sufficient for melting the mass, constitute important items of cost in the copper-smelting process. Numerous cases where fluxing-materials are scarce or dear, or where fuel is expensive, have caused special attention to be given recently to the wet process of copper-extraction, which may be designated as consisting of forming soluble copper salts which are then washed or leached out of the ore or concentrates by dissolving in water or acid. Metallic copper may then be secured from the solution of copper salts by electrolysis; by cementation; or copper can be brought out of the solution as a * Presented also at the Joint Meeting of the Institute and Section IIIa, Metallurgy and Mining, of the Eighth International Congress or Applied Chemistry, New York, N. Y., September, 1912, and here published by mutual agreement.

Dec 1, 1912

By Jay J. Burns

TWO zinc concentrating mills are operated by the St. Joseph Lead Co. in St. Lawrence County, N. Y. The Edwards mill is operating at present only sixteen hours a day treating 400 tons daily. The metallurgy at Edwards presents no unusual problems therefore this discussion is mainly limited to the metallurgy of the Balmat ore. The Balmat mill has a capacity of 1,250 tons per day and the operating crew consists of three shift bosses each with five millmen per shift. Two crusher operators work on each of two shifts and one cleanup man on day shift. The repair crew is made up of a foreman and three repairmen, one of the repairmen being capable of taking over any operating job in the mill from shift boss down. Each millman is capable of handling the next job in line and several men in the yard crew are broken into handling the start-off job in the mill so that temporary shortages of men do not cause extensive overtime. Sphalerite, pyrite, and galena, the principal ore minerals, occur in a gangue of calcite, dolomite, and silicates, especially diopside, plus tremo-

Jan 1, 1947

By Dorsey Hager

THE possibilities of finding new oil pools in Oklahoma and Kansas are far from promising. In 1916, the only new pools of importance were the Franchot pool near Bixby, the Garber, and the Billings pools in Oklahoma, and the Virgil and Utopia fields in Greenwood County, Kansas. In the first 8 months of 1917, a small pool of unknown extent was opened south of the Stone Bluff pool in Oklahoma, and a pool near Casey, Paunee County, Oklahoma. In Eastern Kansas, interest has been. caused by the sinking of new wells near the old Iola pool, but nothing of magnitude has yet been found. The outlook for new pools is far from encouraging, especially as geological surveys have covered all of Oklahoma and Kansas. There are a few areas where geological surveys throw little or no light on the subject, as exposures are poor, but the chances of finding new pools in such areas are slight indeed, if one can judge from the past history of such areas. So far the geologists have based their opinions largely upon the presence or the absence of geologic structure, such as anticlines, domes, and terraces, but some pools will most certainly be found where no surface structure exists, but where local changes in the sand body favor oil accumulations. However, the possibilities of new pools off structure are small, as fully 90 per cent. of the oil pools are on definite structure. In the past, it is estimated that one test in 150 "wild cats" or new tests has brought in a new field. The writer feels safe in asserting that the proportion will decrease still further, so that but one out of 500 new tests may bring in a pay well in a new area. From now on the principal field of work in Oklahoma and in Kansas will consist in developing the present pools. The years 1915, 1916 and 1917 saw the high peak of Oklahoma and Kansas oil production. The Eldorado and the Augusta oil fields present the largest possibilities for continued production in Kansas. These two pools have been scarcely more than one-third developed, and have greater potentialities than any of the present Oklahoma pools. In Oklahoma, pools of magnitude should

Jan 10, 1917