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By Henry Wurtz

Jan 1, 1880

By JAMES J. PURDY

The great majority of stokers used in residential heating installations are of the clinkering type. Because of inherent characteristics of the under- feed combustion process as it occurs in these small stokers, and because of the wide range of operating conditions encountered in residential heating schedules, not all bituminous coals can be used successfully in residential underfeed units. The problem of providing consumer satisfaction has been attacked by the joint efforts of the stoker manufacturers and the coal industry; the stoker manufacturers have been concerned with improving their product to permit the use of a wider range of coals, and coal operators have made every effort to market selected and better prepared coals. In view of the wide range of physical characteristics and chemical properties of bituminous coals, the problems are real and are receiving increased attention.

Jan 1, 1949

By Harrison Everett Ashley

Prof. Hofman's diagrams, Figs. 5 and 7 of his paper, which are reproduced as Figs. 1 and 2 of the present contribution, confessedly fail to show comprehensively the properties of the silicates investigated. Each curve is carefully discussed, and the author has evidently drawn all the conclusions that can be thus reached; but he says :* "The curves do not show, as was hoped, any simple connection between silicate-degree, percentage of lime, and minimum of formation-temperature." There is, therefore, in this case, an excellent opportunity of

Jan 1, 1902

By Theron Wasson

During 1936 the state of Michigan produced 11,868,573 bbl. This is approximately 4,000,000 bbl. less than produced in 1935. The principle reason for the decrease in production over the previous year was the rapid decline of the Crystal field, which reached its peak in October 1935. The old producing area—Mt. Pleasant, Porter, Yost-Clark— accounted for over 7,000,000 bbl. during 1936. Crystal produced a total of 2,400,000. Outstanding among the old fields were Vernon and

Jan 1, 1937

By L. T. Larson, P. M. Basinski

In the northern Reese River Valley uranium is corroded with Middle Pliocene zeolites. These zeolites were diagenetically derived from rhyolitic volcanic glass deposited in a saline- alkaline lake. X-ray diffraction, scanning electron microscopy, and chemical studies reveal clinoptilolite, analcime, and enonite to be pesent and that these minerals can concentrate at least 0.7% uranium from solution. Most anomalous drill cuttings contain zeolite and zeolites are believed to host the uranium. Research suggests the uranium mineralization is conceptually analogous to the Tono mine, Japan.

Jan 1, 1981

By J. P. Zannaras

Referring to the article by R. J. Charles and P. L. de Bruyn, let us assume that W = weight of glass bar; P = weight of hammer; e = total deformation; E = unit of deformation; K = potential stress energy; E = modulus of elasticity; L = length of the bar; 7, = coefficient of inertia; h = height, ft; V = velocity, fps; and a = cross section area. The portion of kinetic energy which is effective in producing stress energy in a fixed bar struck horizontally is given by the formula [ ]

Nov 1, 1956

By T. F. Archbold, W. H. King

THE diffusivities of gold in polycrystalline copper have been determined in the temperature range from 700° to 1000°C by the utilization of the neutron-activation method. Martin, Johnson, and ~saro' used this method for their investigation of the diffusion of gold into copper at 375° and 550°C for 59 days in order to circumvent the experimental difficulties imposed by the 2.7-day half-life of Au-198. They employed the conventional technique of depositing Au-198 on copper specimens for short-time dif-

Jan 1, 1965

By AIME AIME

EVER since Henry Bessemer, nearly 100 years ago, developed the steelmaking process that bears his name, occasional variation has been noted in the quality of steel made in the acid converter, owing largely to the difficulty of stopping the ? refining-which takes only ten to twelve minutes -at precisely the right moment. Principally as the result of this, the amount of Bessemer steel made in the United States gradually declined over the years until it is now about 7 per cent of the total.

Jan 1, 1943

September 28, 1915. The Nominating Committee of the American Institute of Mining Engineers has the honor to present the following nominations for officers of the Institute to be voted for at the 1915 Annual Meeting: For President: L. D. Ricketts District 0 For Vice-Presidents: Karl Eilers District 0 James MacNaughton District 4 For Directors: Thomas B. Stearns District 7 Charles F. Rand District 0 Charles W. Goodale District 5 Edwin Ludlow District 2 George D. Barron District 0 F. W. BRADLEY, Chairman.

Jan 11, 1915

By R. H. Richman, II Conard G. P.

AS part of a study of deformation twinning in bcc crystals, solid solutions of beryllium in iron have been found to twin profusely when strained slowly at room temperature. This note reports some crystal-lographic aspects of the operative mechanical twin modes in a quenched Fe-5 wt pct Be alloy. After melting twice under a partial pressure of helium, the alloy was homogenized, cut into pieces 7 to 10 mm on an edge, solution treated at 1130°C,1 and quenched. Debye-Scherrer patterns confirmed

Jan 1, 1963

By Henry Wurtz

HERACLITUS, a sage of antiquity, called the dark philosopher, who refused a throne, preferring a hermit's cell, propounded, twenty-four centuries since, the maxim : [ ] War (or strife) engenders all things. This, though probably intended by Heraclitus to apply especially to the internal forces of nature, is often said, with equal reason, of the affairs of men. Controversial strife, whether fortunately or unfortunately, is a crucible through which all new discoveries in science, and all technical applications of science must pass-a test which they must all endure before they can become so vitalized as to germinate, so to speak, take root in the human mind, grow tip, and overspread the earth. The greater the number and the power of the elements arrayed against such a growth, and of the influences hostile thereto, the greater should be the inherent vitality of the germ, the more strenuous, skilful, and persistent its cultivators and upholders. During the decade last past we have had, in spite of the severe stringency of the times, an active growth of this kind in progress, whose prospective importance it would now be difficult to overrate. This is the movement which has for its motive the idea that, generally speaking, fuel should be gaseous in form, and which has for its goal the introduction into general public use of gaseous products, made by cheap and rapid processes and on a gigantic scale, distributed throughout our cities and towns in distribution-systems which shall be proportionately gigantic, and sold at prices which will bring such fuel within the means of the poorest householders. Personally, for ten years past, the writer has never failed, on occasions public or private, to urge his belief that the realization of this idea, deemed by him a certainty of the future, will bring about

Jan 1, 1880

By Thirumalai, K.

Although the term "spalling" has long been known, Norton l first referred to its usage for the fracture or disintegration of materials subjected to rapid temperature changes. Spalling of ceramic materials at high temperatures has received attention in the past. Removal of the char formed during ablation in re-entry of space vehicles has been referred to as mechanical spalling. The first experiments to evaluate the process of rock fragmentation by thermal spalling were conducted by Stoces using a series of gasoline burners on the quartz veins of the Zinnwald deep mines in Germany. After the development of rocket-jet burners, the principles of 'thermal spalling combined with high fluid momentum found wide practical application in rocks. The well-known jet piercing process for drilling blastholes in taconite and for jet channeling in the quarrying of granite are among the more notable of these application^.

Jan 1, 1970

By K. A. Slagle, D. K. Smith

weight obtained. Additives used in conjunction with salt in these slurries have included silica flour, calcium ligno-sulfonate and cellulose retarders, granular lost-circulation materials, bentonite and selected low-water-loss additives that are not significantly deteriorated by the presence of the chloride ion. In some other areas of South Texas, the salt-saturated slurries have been used quite extensively for improvement of the flow properties of slurries and attainment of better circulation characteristics at lower displacement rates. Concurrently with this property, the protection of shales and shaly sands is also realized, as well as useful retardation of the slurry. Resultant superior cementing jobs have been indicated by both communication tests and acoustic logs for bonding to pipe and formation.' In one section of Louisiana, a major oil company has been using salt-saturated API Class A cement with calcium lignosulfonate retarder for cementing through the Miocene at 9,000 to 10,000 ft. This is another of the situations where interbedding of sands and shales exists, creating difficulty in maintaining formation competency when a fresh-water slurry contacts the clay minerals of the formation. Further work has also been done in the shaly Miocene formation at 13,000 to 15,000 ft where fairly close water or gas contacts are encountered. Indications thus far are that better segregation of these various fluids is obtained by use of the saturated salt slurries because of their improved formation bonding characteristics. In addition to the properties of salt in this situation, attainment of turbulent flow at minimum displacement rates has also been accomplished by use of an additive to help provide exceptional dispersion and viscosity reduction of the slurry. Another oil company was encountering considerable expense in completing wells in Southwestern Louisiana due to extensive block squeeze requirements for effective separation of zones. A very effective mud program was being used to minimize washout in the shale sections and, apparently, a nearly gauge-size hole was being obtained. However, primary cementing results with fresh-water slurries were generally poor. On a few occasions when slurry was actually circulated to the surface, large pieces of shale formation were brought out of the hole with the slurry, indicating a severely water-sensitive, sloughing formation. Inhibition of shale heaving was being accomvlished in the drilling program, and immediately indone ipon circulation of the fresh-water slurry even though it contained a low-fluid-loss additive to reduce filtrate damage in the sands. The subsequent change to salt-saturated slurry yielded 11 successful primary cement jobs out of 12, compared to the previous success ratio of practically zero. Since these were deep, high-temperature wells in the range of 13,000 ft with high-pressure zones necessitating 17.5-lb/gal fluid densities, the slurry used was API Class E cement, silica flour, weight material, retarder, salt saturation (which also reduced the amount of weight material) and maintenance of low fluid loss by use of a salt-compatible additive. Other salt slurries have been used to a limited extent in this same general area for similar problems at depths ranging from 5,000 to 17,000 ft. In the shallower wells, the cement has usually been API Class A where the salt functions as a retarder, and in the deeper wells API Class E cement is used with the additional salt advantage being its increased slurry weight and inability to dissolve salt stringers. A considerable number of squeeze jobs have also been done on older wells using the salt-saturated slurries with very good results. MID-CONTINENT In North Texas, salt-water slurries have been used for cementing the Woodbine sand, Strawn sand, KMA sand and Pettit lime. Shales surrounding these formations have created the same difficulty in obtaining separation of producing zones that has been the problem in other areas. Depths in this area range from 3,400 ft for the Strawn to 7,400 ft for the Woodbine, and concentration of salt has varied accordingly. In the deeper wells, where retardation is desired, saturated salt-water cement is used; for the shallower wells, in order to provide shorter waiting-on-cement times, the amount of salt has been 18 per cent by weight of the mixing water. Results have been excellent with no reported failures on any of the salt cement jobs; where acoustic bond logs have indicated indifferent bonds previously, they are indicating very good bonding for the salt slurries. In Oklahoma various shales of Pennsylvanian age exhibit a high degree of sloughing in the presence of fresh water, causing severe washouts above and below sand formations which it is desired to isolate. This situation exists to some degree in practically all parts of Oklahoma and includes formations of other ages such as the Wood-ford shale. For the past few years, salt-saturated cements and displacement rates as high as practical have been used as a remedy for this problem, with very good results. The Layton and Bartlesville formations are two examples of shaly sands where saturated slurries have been helpful. In one area where five wells were drilled through this type of problem shale without obtaining a satisfactory primary cement job, a change was made to salt-saturated cement preceded by a suitable chemical wash for the drilling mud involved. Acoustic bond logging indicated excellent bonding, and final completion bore out this result by being trouble-free. This type of slurry has also been used extensively on squeeze jobs where shales have been heaving around the producing formations. Predominantly, the basic slurry has been either API Class A cement or a pozzolan cement—although, as deeper wells are being drilled, the use of salt in Class E cement is also increasing. Salt cement in West Texas has been used primarily to help prevent channeling through the shales around the Delaware sand, Queens dolomite and Hope lime. Many of the shaly and dirty sands of this area are sensitive to the filtrate from a fresh-water cement. Salt at 16 to 18 per cent by weight of mixing water has been added to centent, and has been effective in controlling formation damage and communication between zones in these formations. Use of these lower salt concentrations is dictated in this area by the relatively low formation temperatures where retardation of the slurry would create unduly long waiting-on-cement times. Also, quite a bit of cementing has been done in this area using salt concentrations in the accelerating range— that is, 2 to 5 per cent by weight of water. Specifically, these concentrations have been used in coiljunction with high percentages of gel to overcome the retarding effect of the calcium lignosulfonate dispersant, although there are probably several shales where these concentrations could provide some degree of formation stability. On several occasions, the salt has also been used to lower the critical velocity or rate for turbulence with the slurry, particularly in the pozzolan cements. On wells in the Hope lime, it has usually been necessary to squeeze the shale above and below the lime to get a water-free completion. Use of salt-saturated slurries has largely eliminated this

By Charles R. Keyes

I. Introductory,.......... 185 II. Hypotheses oF the Origin of OzaRk Ores..... 186 1. General Considerations........ 186 2. Schmidt-Leonhard and Gage View...... 187 3. Jenney Opinion.......... 187 4. Posepny Idea,.......... 188 5. Winslow-Robertson Hypothesis....... 188 6. Branner Proposition......... 189 7. Keyes Statement.......... 189 8. Van Hise-Bain Theory........ 190 III. Requirements of an Adequate WoRking-Hypothesis,... 190 IV. GeneRal Geotectonics of the OzaRk Region.... 192 1. Salient Aspects.......... 192 2. Geologic Formations......... 192 3. Character of Faulting...192 4. Extent of Flexing......... 193 5. Unconformity Inequalities....195 6. Warping of Strata...195 V. Classes of Ore-Deposits... 196 VI. Vadose ORe-ConcentRation,........ 197 VII. GeogRaphic DistRibution of the Ore-Bodies,... 199 VIII. Relation of ORe-Deposit to Geologic Structure... 201 1. General Occurrence of Ore-Bodies in Basins.... 201 2. Deposits of the Central Missouri District..... 203 3. Deposits of the Southwestern Missouri District.... 203 4. Deposits of the Northern Arkansas District... 305 5. Deposits of the Southeastern Missouri District.... 206 6. Synclinal Ore-Deposits of Other Districts.....207 7. Significance of Ore-Troughs in Prospecting... 209 8. Origin of the so-called Synclines,...210 9. Significance of the Cross-Bars of Joplin..... 213 10. Relation of Ore-Run to Ancient Relief-Features,... 215 IX. Direction of GRound-Water Circulation..... 216 X. VeRtical Range of Workable Ore-Bodies,... 218 XI. Oscillation of Ground-WateR Level...... 219 XII. Relations of Ore-Bodies to Lithoclasic Features,.. 220 XIII. PRimaRy Source of Ore-Materials,...... 220 XIV. Zone of Ore-Enrichment,......... 222

Jan 1, 1910

By A. W. Ross, William Marsh Baldwin, T. S. Howald

The related subjects of preferred orientation, directionality in physical properties, and earing tendencies of wrought metal strip have attracted the attention of metallurgists to such an extent that in the past 20 years hundreds of researches have been published on this one general problem. The anisotropy of tensile strength and elongation have been exhaustively studied in their relationship to the occurrence of ears in cups drawn from strip'-~O.~g and, to a lesser extent: yield strength7."-l7 and stress-strain curves'5 have been investigated. Despite the tremendous fund of knowledge thus accrued, no simple quantitative correlation of directionality and earing tendencies has yet been found. In a sense, this is not surprising. The formation of ears in a drawn cup clearly is a special phase of the general study of metal flow; in particular (as will be brought out in the course of this paper), ears are due to anistropy in the rates of deformation of the metal in the radial, circumferential, and "thickness" directions of the original blank. It would be difficult to effect a correlation between caring tendency and a property that may be completely independent of the flow of metal, or at best related to metal flow in an exceedingly complex fashion. Yet, it is this correlation that has been attempted; tensile strength and elongation are attributes of metal rupture. a phenomenon that has quite admirably been shown to be distinct from the phenomenon of metal flow,21 while yield strength and stress-strain

Jan 1, 1946

By William Marsh Baldwin, T. S. Howald, A. W. Ross

The related subjects of preferred orientation, directionality in physical properties, and earing tendencies of wrought metal strip have attracted the attention of metallurgists to such an extent that in the past 20 years hundreds of researches have been published on this one general problem. The anisotropy of tensile strength and elongation have been exhaustively studied in their relationship to the occurrence of ears in cups drawn from strip'-~O.~g and, to a lesser extent: yield strength7."-l7 and stress-strain curves'5 have been investigated. Despite the tremendous fund of knowledge thus accrued, no simple quantitative correlation of directionality and earing tendencies has yet been found. In a sense, this is not surprising. The formation of ears in a drawn cup clearly is a special phase of the general study of metal flow; in particular (as will be brought out in the course of this paper), ears are due to anistropy in the rates of deformation of the metal in the radial, circumferential, and "thickness" directions of the original blank. It would be difficult to effect a correlation between caring tendency and a property that may be completely independent of the flow of metal, or at best related to metal flow in an exceedingly complex fashion. Yet, it is this correlation that has been attempted; tensile strength and elongation are attributes of metal rupture. a phenomenon that has quite admirably been shown to be distinct from the phenomenon of metal flow,21 while yield strength and stress-strain

Jan 1, 1946

By J. Blodget Britton

During the last three or four years I have had occasion to examine, chemically, various samples of matter commonly called flue-dust or cinder, found deposited in the flues and hot-blast chambers and under the boilers of blast furnaces, and also in the flues and under the boilers of puddling and boiling furnaces. Recently several of these examinations mere made quite in detail, and as the results reveal, I believe, information of no inconsiderable importance, I am induced to communicate them to this Institute. A sample of deposit obtained from the flues of one of the blast furnaces at the works of the Phœix Iron Company, at Phœnixville, Pa., was found to have the composition given in Column I of the following table: I. 11. 111. Composition of Dust from Dust from Dust from Deposits. Blast Furnace. Puddling Furnace. Boiling Furnace. Protoxide of iron,... 1.51 3 08 1.18 Peroxide of iron,... 20.21 33.29 41.00 Alumina,....6.57 12.89 7.54 Lime,.....3.98 .48 .61 Magnesia,.....69 .09 .19 Protoxide of manganese,. . 1.66 .39 .12 Oxide of zinc,....2.84 ........ Oxide of copper,. .. ..06 ........ Silicic acid,....36.00 40.69 38.99 Sulphuric acid,... 7.55 .43 Phosphoric acid,..94 ..94 Arsenious acid,. .. .38 Antimoniousacid,... trace.......... Chlorine,....03 ..03 Cyanogen,.....09 ........ Ammonia,.... trace......... Pottlsh with some sodn,. .. 16.61 ........ Carbonic acid,. .. .. .59 ........ Alkalies, undetermined matter, and loss,.......29 4.49 6.96 100.00 100 00 100.00 Metallic iron,. 16.31 25.70 29.64 Phosphorus,. .. .. .41* 1.55† 1.30†

By R. S. Sandhu, L. E. Baker, W. Y. Shieh

The finite element method of analysis was introduced by Clough.1 Within a short period, it has developed into a powerful solution technique in structural and continuum mechanics. It has been used to solve boundary value problems in two and three-dimensional elasticity.2-5 Anisotropy and heterogeneity of materials were allowed for at the earliest stages. 1,4 Its application has been extended to allow for cracks,5 creep and viscoelasticity, 6,7 incremental construction,6-8 nonlinear elasticity3,9 effect of joints in rock,10 and to materials with different behavior in tension and compression.7 Because of its versatility, the finite element method has found increasing application in the field of rock mechanics. In fact, several of the more significant developments have been motivated by problems in this field. Elasto-plastic material behavior based on the incremental or rate-type theory of plasticity rather than the deformation theory was considered by Reyes and Deere11 A material law based on a generalization 12 of the Mohr-Coulomb criterion was used. In this chapter, the formulation of material laws developed by Reyes and Deere 11 is used. An efficient analysis procedure, incorporating recent developments in finite element analysis, is developed for plane-strain conditions. To demonstrate its effectiveness, the procedure is applied to three cases, one for which an exact solution is available, another for which field observations had been made, and a third one for which a parallel study was made, using an accepted limit-equilibrium method.

Jan 1, 1970

By F. A. Forward, J. Halpern

A new process is described for extracting uranium from ores containing sulphidic minerals, which comprises treating an aqueous pulp of the ore with air or oxygen at elevated temperatures and pressures. The acid required to dissolve the uranium is generated during the leach through oxidation of the sulphides. The chemistry of the process is discussed and laboratory results are presented to illustrate the operation of the method and the variables which control it. With most ores, leaching at a temperature of 130°C and an oxygen partial pressure of 10 psi provides uranium extractions of 90 to 95 pct in 4 to 6 hr. The acidity and level of dissolved impurities in the leach liquor can be kept fairly low. The method is characterized by a number of advantageous features including low reagent cost, short retention times, and high recoveries. RECENTLY there have been developed several processes for extracting metal values from ores by pressure leaching techniques;' -' an example is the carbonate leaching process for uranium ores which has been studied in this laboratory.' Leaching is carried out under oxygen pressure to ensure oxidation of the uranium to hexavalent compounds which are soluble in carbonate solutions. During the course of investigations relating to this process, it was observed that sulphide minerals, such as pyrite, usually were oxidized under the conditions of the leach treatment resulting in the formation of iron hydroxides and sodium sulphate, i.e. 2 FeS= + 7Vz O2 + 8 Na,CO3 + 7 H,,O -* 2 Fe(OH)3 + 4 Na2SO4 + 8 NaHCO.,. [1]

Jan 1, 1956

By S. R. Gilbert, B. W. Burdett, L. B. Hales

INTRODUCTION Grinding control is currently the most publicized control subject in the minerals industry. Flotation control and crushing control have not as yet received the widespread attention that grinding control has. The primary reasons for this center around the high capital costs of grinding equipment and the fact that grinding mills are extremely energy inefficient. In a typical copper concentrator the energy requirements to produce refined copper are: (1) [Total Energy Distribution (Kw-hr/yr)% Mining4.93 x 10817.3 Mineral Processing9.63 x 10833.8 Smelting and Refining13.9 x 10848.9] One-third of the total energy used for copper production is for mineral processing. A breakdown of this energy into process steps yields the following: [Total Energy Distribution (Kw-hr/yr)% Crushing and Grinding 7.16 x 108 73.8 Flotation 0.76 x 108 7.8 Materials Handling1.78 x 10818.4] It is apparent that comminution operations consume the largest proportion of the energy for processing and as such become major targets for improvements in efficiency. Unfortunately, size reduction operations are extremely inefficient. Efficiency calculations for grinding range from less than 0.1% to about 5% depending on the evaluation criteria. Because of these facts, grinding control has been and will continue to be the focus of major process control efforts. OBJECTIVES AND BENEFITS All benefits achieved as the result of grinding control are derived from modifying physical parameters which improve the efficiency of the grinding mill. These parameters include:

Jan 1, 1982