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By Carl G. Hogberg

During recent months, the acute shortage of steel scrap has necessitated the use of higher percentages of hot metal in the open-hearth charge. With these higher percentages, the sulphur content of hot metal has become an increasingly important factor in the control of the quality of steel. Thus, the blast-furnace operator is faced with a demand not only for more output but for a higher quality of product. More than go per cent of the sulphur charged into the blast furnace is contained in the coke. With the tremendously increased demand, the trend of coke quality has been toward higher sulphur, higher and more variable ash, and poorer physical characteristics. This has been brought about by less selective coal mining, increased production rates in coke plants and resumption of operations of many beehive ovens. In a single month last year, one blast-furnace plant in the Pittsburgh district operated with coke obtained from 52 sources. The effect of variability and quantity of coke ash on blast-furnace operation is well known. The improved results obtained with furnaces operating on coke made from washed coals compared with results on coke made from raw coals is ample proof of the effectiveness of low and uniform ash. Coal-washing plants, however, require a large capital expenditure, and are impractical for most of the large number of small producers, whose operations are confined chiefly to periods of abnormally high demand. Furthermore, not all coals are physically adaptable to washing. Principles 01 Iron Desulphurization in Furnace Although investigations of the blastfurnace process have not clearly revealed the detailed mechanism of iron desulphuri-zation within the furnace, they have been sufficiently extensive to permit a postula tion of the following general principles: 1. Iron, in its travel from furnace top to hearth, continues to pick up sulphur until it has reached tuyere level. The zone of iron desulphurizatioil is relatively narrow, being confined to a vertical distance extending zapproximately from tuyere level to the iron-slag interface in the hearth.' 2. Combustion of coke is confined to spherical zones extending approximately 40 in. from the nose of each tuyere.= Coke ash is released as the coke bums in these combustion areas. 3. With a constant amount of sulphur in the charge, the sulphur content of the metal product is a function of hearth temperature, final slag analysis, slag viscosity, and slag volume. Both hearth temperature and slag analysis affect slag viscosity. For a slag of constant analysis, viscosity always decreases with an increase in temperature;

Jan 1, 1943

By D. B. Barker, D. C. Holloway, J. F. Cardenas-Garcia

Tround International Inc. is currently developing a hard rock drill that uses a salvo of three frangible projectiles to prefracture the rock ahead of a conventional tri-cone bit. This paper reports on a series of experiments conducted for Tround to study the fragmentation enhancement possible through the use of an optimally timed and spaced salvo of projectiles. In this study the complex three-dimensional problem was simplified to a two dimensional salvo impact problem in a transparent brittle plate of glass. The use of high speed photography and dynamic photoelasticity was then used to study the development of the impact damage zone and the various interactions of the stress waves.

Jan 1, 1982

By J. H. Scaff, J. E. Kunzler

The measurement of the electrical, thermal, and magnetic properties of metals at low temperatures, primarily in the range of liquid helium below 4.2°K, is a powerful tool for investigating many of the fundamental properties of the metallic state. Such measurements also have many practical applications, particularly as an analytical tool. One example of the practical utility of such measurements is illustrated by a short study we have made of the low-temperature resistance of copper used in preparing varistors. Copper-oxide varistors are prepared by the thermal oxidation of copper. This results in the

Jan 1, 1959

By O. S. True, C. H. Herty

It is well known that manganese will desulfurize molten iron through the formation of manganese sulfide, which, being only slightly soluble in the metal, rises to and enters the slag where it remains as such (mixer slag) or is converted partly or wholly to calcium sulfide (basic open-hearth slag). The reaction by which manganese sulfide is formed is Mn + FeS = MnS + Fe. This reaction is generally considered to be reversible, although McCancel states that such is not the case. The experimental work was carried out to confirm the results of Roh12 as to the reversibility of the reaction. Six trials are herein considered. In each 200 gm. of electrolytic iron free from manganese and sulfur were melted in a pure zirconia crucible in a carbon resistance electric furnace. To the melted iron in runs 2, 3 and 4 metallic manganese and manganese sulfide were added to give 1, 2 and 4 per cent. manganese respectively, with 0.50 per cent, of sulfur in each. In runs 5, 6 and 7, metallic manganese and iron sulfide to give the same proportions of. manganese and sulphur as in runs 2, 3 and 4, were added. The melts were held molten in the furnace for an hour and then cast into small ingots. The results of these melts are as follows: Ingredients of Charge Analysis or InRot ManOaneBe, SulfUR, ManOaneBe. SULFUR, Run Material Charged PeR Cent. PeR Cent. Per Cent. PeR Cent. 2 MnS + Mn............... 1.0 0.452 0.636 0.367 3 MnS + Mn............... 2.0 0.50 1.57 0.310 4 MnS + Mn............... 4.0 0.50 2.81 0.230 5 FeS + Mn................ 1.0 0.50 0.647 0.397 6 FeS + Mn................ 2.0 0.50 1.45 0.374 7 FeS + Mn................ 4.0 0.50 2.73 0.195

Jan 1, 1925

By Klaus Detert

Fifteen and 18 pct Ni maraging steel and several binavy and ternary alloys of the iron-rich corner of the Fe-Co-Ni system have been studied. After annealing in the austenite range, these alloys were deformed slightly by cold rolling and subsequently aged. Compavison of experimental measurements at various processing stages indicates that small degrees of deforn~ation (5 to 10 pct reduction in thickness) do not influence hardness and strength or the aging kinetics. Electrical resistivity and ductility are somewhat redu]ced and the coercive force is substantially lower when compared to identical samples which were not deformed. The results are explained in terms of retained austenite which transforms into martensite with the small amount of deformation. RECENTLY there has been increasing interest in maraging steel for applications in electric power generators requiring a high ratio of power to weight.' Fifteen pct Ni maraging steel has been investigated to evaluate its properties and performance for application as high-strength magnetic rotor steel,' and a thorough investigation of the precipitation and transformation processes in this alloy has been conducted in this laboratory.3 The influence of deformation, which preceded the aging treatment, was also studied. It was found that a small deformation in the order of 5 pct has a rather striking effect in reducing the coercive force. Other interesting effects on the properties caused by such deformation have led to the more detailed studies reported herein. EXPERIMENTAL METHOD The methods used to produce the samples from 15 pct Ni maraging steel have been described elsewhere.3 The general procedure of hot forging and cold rolling to sheet has been followed. The composition is included in Table I which also contains the composition of the 18 pct Ni maraging steel grade 250 studied. More data about the material and the processing of the 18 pct Ni maraging steel have been recently reported.4 The experimental alloys of binary and ternary Fe-Ni-Co alloys were made by levitation melting in an argon atmosphere and casting into rod-shaped ingots 7 mm thick weighing 20 g. From these ingots 25-mm-long rods were machined to study the phase transformation by a dilatometer. These rods were then cold-rolled to strips, 2.4 mm thick. Annealing for austenitizing was done in tube furnaces in an argon or helium atmosphere followed by cooling in the water-cooled portion of the tube. Aging was done in a salt bath containing a neutral blend of Alkali nitrates and nitrites. Vickers hardness was measured using a load of 50 kg for 15 sec. Tensile tests were carried out on a hard beam tensile tester at a strain rate of 5 X lo-' per sec using flat samples with a gage length of 37.5 mm and a cross section of 1.25 by 6.25 mm. Estimated sensitivity was 5 K x strain and 0.35 kg per sq mm stress. Magnetic saturation was determined on small cylindrical samples, 2.5 mm in length and diameter, by measuring the force exerted by the gradient of a magnetic field of 1000 oe per cm in a mean field of 11,500 oe. The measured values could be reproduced within *1 pct. Coercive force was measured by a precision-type magnetic field probe in a magnetic coil as described by Foerster.5 The magnetizing field was 1300 oe. The samples were 5 cm long, 1 cm wide, and 2.4 mm thick. he coercive force was measured to within +0.1 oe. Electrical resistivity was measured by using a potentiometer on flat strips with a gage length of 100 mm and a cross section of 2.5 by 0.5 mm. The accuracy of the measurement was 0.1 pct but the reproducibility of the measured specific resistivity among different samples was in the order of 1 pct. The method used to prepare the samples for electron transmission has been reported elsewhere.3 RESULTS Fig. 1 shows the influence of deformation after annealing on the resistivity, hardness, and coercivity. The samples were annealed for 30 min at 1000"C,

Jan 1, 1968

By R. A. Greenkorn, R. C. Smith

Hele-Shaw cells are used to model creeping flow through porous media (where Darcy&apos;s law is valid). The effects of inertia on flow about obstructions in a Hele-Shaw cell can be calculated by a perturbation method if one can determine a solution to Laplace&apos;s equation. Results of a computer solution for flow about circular, square and elliptical obstructions are presented. These results show that or a modified Reynolds number of less than I, the inertia terms are small; and for values of less than 3, the average streamline predicts the ideal flow. Therefore, the analogy might be used for studying flow in porous media up to a modified Reynolds number of at least 3. INTRODUCTION The nature of fluid flow in porous media is of interest in the fields of soil mechanics, ground water flow, petroleum production, filtration and flow in packed beds. Because it is very difficult to study the phenomenological behavior of flow in porous media, homologs and analogs are used to study flow characteristics. A Hele-Shaw model, made of two closely spaced plates - usually glass — is often used as an analogy to two-dimensional flow in porous media. Hele-Shaw2 showed experimentally that the streamline configuration for creeping flow around an obstacle located between two closely spaced parallel plates is the same as for two-dimensional, ideal flow about the same obstacle. Stokes7 verified these observations mathematically. The usual equation of motion for flow in porous media is Darcy&apos;s law. The form of the mathematical statement of Darcy&apos;s law is identical, within a multiplicative constant, to the expression for the average velocity over the plate gap in the plane of a Hele-Shaw model. These models may be used to describe flow in both homogeneous and heterogeneous porous media. In the mathematical proof of the Hele-Shaw analogy it is assumed that the convective terms in the Navier-Stokes equations are negligible and that the equations of motion degenerate to Laplace&apos;s equation, with pressure the dependent variable. Whenever a Hele-Shaw model is used as an analogy to flow in porous media, .the validity of this assumption is in question. Riegels5 showed that if convection is not neglected, the velocity distribution around a cylindrical obstruction in the flow field depends on a Reynolds number, the plate spacing, and a dimension characteristic of the obstacle. Riegels&apos; solution, a perturbation solution, uses the boundary condition that the flow rate into the obstacle averaged over the plate gap at any point on the obstacle is zero. The method requires that a solution to Poisson&apos;s equation for the perturbation pressure be found. Riegels evaluated this solution for the case of the cylindrical obstruction. His method may be simplified by eliminating the need for solving Poisson&apos;s equation for the perturbation pressure. Instead, an analytic expression for the perturbation pressure gradient is obtained (valid for arbitrary shapes) and used to eliminate pressure from the equations for the perturbation velocities. The results show, for symmetrical shapes, that if NRe < 1, the convective acceleration terms are small, and that the average velocities represent ideal flow up to at least NRe = 3, where: L is a characteristic dimension of the obstacle perpendicular to flow, b is the plate spacing, u is viscosity, v, is velocity of approach and p is density. THEORY* Incompressible fluid flow through a Hele-Shaw model and a porous medium are analogous because the equations for the average velocity components in two-dimensional flow are identical if:

Jan 1, 1970

By Joel H. Watkins

The terms kaolin, china clay, ball clay, and paper clay are more or less loosely and interchangeably applied to a large class of white-burning clays. These clays are made up chiefly of hydrous amorphous (colloidal) aluminum silicates with variable amounts of free silica and other impurities in small quantities. Occasionally also the term kaolinite is wrongly applied to a white-burning clay, for kaolinite is a mineral of definite chemical composition and definite crystalline form which occurs but sparingly in nature. It is not the purpose of this paper, however, to define or classify clays, or to enter into a discussion of the chemistry of clays. It is rather a general description of the occurrence and methods of mining of a kindred group of clays, and a discussion of their future economic aspect. In the Southern Appalachian States, the mining of white-burning clays has in recent years become an important industry. Although these clays are of several distinct types, which occur in as many localities under different geologic conditions, they are for the most part primarily of the same origin. They are essentially the same in elementary constituents, and are largely consumed in the game industrial arts. From the standpoint of a mining engineer, therefore, and for convenience in comparison and correlation, it should be interesting to discuss them under one heading. Kinds of Clay The most important types of clay which are now being actively mined in the Southern Appalachian States and with which this paper is particularly concerned are the North Carolina, Virginia, and Georgia kaolins or china clays (residual); the South Carolina and Georgia kaolins or paper clays (sedimentary); and the Florida and Tennessee plastic kaolins or ball clays (sedimentary). Other varieties which are interesting but which are as yet of little importance are the pocket deposits of white clay in Augusta County, Virginia, the bauxitic kaolins of Tennessee,

Jan 1, 1915

By A. U. Seybolt

Experiments on both suljidation and hot corrosion have been carried out using ternary Ni-Cr-X alloys and commercial nickel-base superalloys. It has been shown that lhere are certain micro structural similarities between sulfidation using H,S/H2 mixtures and hot corvosion using Na,S04 in "crucible" experiments or hot corrosion tests using a flame tunnel apparatus. It is proposed that two key processes in the hot cowosion process are: 1) formation of chromium sulfides which deplete the alloy matrix, and 2) oxidation which can be accelerated because of chromium depletion. Other processes play an important role in the hot corrosion process, such as accelerated oxidation attack due to the presence of a N& S04 or N&SO,- NaC2 film which inhibits the formation of a protective external oxide scale. However, this latter phenomenon was not studied in this work. THE term hot corrosion has come to mean a combination of sulfur and oxygen attack on nickel-base or cobalt-base superalloys used as gas turbine blades or partitions. This attack can be initiated by any combustion process in air involving fuel containing sulfur if the sulfur level is sufficiently high. Levels of 5 pet SO2l for example, in the combusting gas have been observed to produce hot corrosion attack on nickel-base alloys. The important immediate corroding medium in aircraft gas turbines, however, has been established to be Na2S04, formed from reaction between NaCl from sea air and sulfur in the fuel.&apos; The Na2S04 concentrates the sulfur sufficiently so that superalloy parts heated in the range 1400" to 1900°F can become sulfided by reducing the Na2S04 film which forms on the parts, and this reaction allows sulfur to gain access to the alloy. The sulfur thus released diffuses into the superalloy and forms primarily chromium sulfides of various compositions, but frequently Cr2S, has been identified. Figs. 1 and 2 show the morphology typical of hot corrosion of a cobalt-base superalloy X-45 (25 Cr, 10 Ni, 7.5 W, 0.25 C) and a nickel-base alloy, Udimet 500 (19 Cr, 19 Co, 4 Mo, 3 Ti, 2.9 Al, 0.07 C). Both alloy samples were subjected to the same hot corrosion conditions: 616 hr at 1600°F in a combusted 2.9 pct S distillate oil containing 125 ppm Na as NaC1. It will be noted at once that the nickel-base alloy is much more severely attacked. The depth of corrosion is much greater and the number and size of the sulfides present are much greater. Both alloys show a duplex oxide scale, which is more noticeable in the X-45 alloy. The external scale is probably a spinel in both cases, with CrQ3 lying next to the alloy. Many investigators1 -"ve been concerned with hot corrosion phenomena, but there has been a lack of unanimity of opinion as to the details of the hot corrosion mechanism. More than one definition of hot corrosion is possible. Some investigators con- sider as a measure of hot corrosion only the weight gain due to an accelerated oxidation. However another point of view is that the total depth of affected alloy may be used as a measure. While it is recognized that surface oxidation attack is greatly accelerated by the presence of salts like Na2S04 or Na2S04-NaC1 mixtures, sulfur penetration into the alloy also undoubtedly produces very important effects. The region of sul-fide penetration which is so prominent in Fig. 2 is one of the outstanding characteristics of hot corrosion. For highly stressed parts, such as first-stage buckets, this sulfur-penetrated region can be more significant in mechanical property loss than the reduction of cross section produced by the formation of the massive external scale. In addition, evidence will be presented that this sulfided region can be less resistant to subsequent oxidation attack. Since it appears that the sulfided region below the surface oxide scale plays an important role in the overall corrosion process,

Jan 1, 1969

By George A. Morrison

A deposit Of limestone Was known to exist at a depth of 2000 ft under the property of the Columbia Chemical Division of the Pittsburgh Plate Glass Co. at Barber-ton, Ohio. A 662-acre site was selected for the projected mine, some two miles northwest of the plant and near the main line of the Erie Railway. An electric railway 8800 ft in length connects the mine and the plant. The deposit is overlain by 18 ft of un-consolidated (sand and gravel), 100 ft of water-bearing sandstone, and finally 2080 ft of shale into which thin layers of sandstone are embedded. The limestone bed itself is 345 ft thick and overlies 200 ft of gypsum. A 300-ton-per-hour capacity mine was decided upon. Two shafts were deemed advisable, one for production and the second for service; and these were sunk 550 ft apart, one to a depth of 2323 ft and the other to 2258 ft. Each is 16 X , ft in the clear and timbered with 6-in. steel H-sets on 8-ft centers, using 3/8 X 4 X 4-in. angles as studdles. Twelve inch I-beams were used at 160 ft intervals as bearers set in deep hitches and concreted to a vertical depth of 8 ft. Wooden sheathing was first employed but sloughing of the shale created a pressure on this lining and finally concrete was deemed necessary. Water was encountered only within the first 315 ft, flowing at 60 gpm and by grouting this was reduced to 15 gpm. Temporary wooden sinking headframes were installed with 300 cu ft capacity storage pockets and with doors automatically controlled by air cylinders by hoistmen. Each shaft was operated on four 6-hr shifts. The usual V-cut was drilled at the center of the shaft and the round consisted of 34 holes- A 40 pet gelatin dynamite was employed with some 60 pet in the cut holes. Drilling crews consisted of four to six men. Shale drilled easily but became more bed in depth and sandstone wore away the gauge Of the bits rapidly. A room-and-pillar mining system was adopted whereby rooms turned off on 80-ft centers, each room 40-ft wide and 50-ft high. Rib pillars between rooms were cut into 100 ft lengths by frequent holes. Ventilation is achieved through the two shafts, the down-draft through the service shaft, and the return through the pr0duction shaft. The hoist has a a Of 300 tons per hour and is equipped with 10-ton balanced skips requiring. a 2-min cycle Or 30 trips Per hour- Hoisting is designed to Operate by automatic loading and no hoistman is required for normal Operation. The 48 X 60 in. jaw primary crusher is underground. It is fed through chute and chain feeders and is flood-oil lubricated and cooled. An inclined belt conveyor returns oversized material to the crusher. Tramming is by Diesel-powered trucks.

Jan 1, 1948

By George A. Morrison

A deposit Of limestone Was known to exist at a depth of 2000 ft under the property of the Columbia Chemical Division of the Pittsburgh Plate Glass Co. at Barber-ton, Ohio. A 662-acre site was selected for the projected mine, some two miles northwest of the plant and near the main line of the Erie Railway. An electric railway 8800 ft in length connects the mine and the plant. The deposit is overlain by 18 ft of un-consolidated (sand and gravel), 100 ft of water-bearing sandstone, and finally 2080 ft of shale into which thin layers of sandstone are embedded. The limestone bed itself is 345 ft thick and overlies 200 ft of gypsum. A 300-ton-per-hour capacity mine was decided upon. Two shafts were deemed advisable, one for production and the second for service; and these were sunk 550 ft apart, one to a depth of 2323 ft and the other to 2258 ft. Each is 16 X , ft in the clear and timbered with 6-in. steel H-sets on 8-ft centers, using 3/8 X 4 X 4-in. angles as studdles. Twelve inch I-beams were used at 160 ft intervals as bearers set in deep hitches and concreted to a vertical depth of 8 ft. Wooden sheathing was first employed but sloughing of the shale created a pressure on this lining and finally concrete was deemed necessary. Water was encountered only within the first 315 ft, flowing at 60 gpm and by grouting this was reduced to 15 gpm. Temporary wooden sinking headframes were installed with 300 cu ft capacity storage pockets and with doors automatically controlled by air cylinders by hoistmen. Each shaft was operated on four 6-hr shifts. The usual V-cut was drilled at the center of the shaft and the round consisted of 34 holes- A 40 pet gelatin dynamite was employed with some 60 pet in the cut holes. Drilling crews consisted of four to six men. Shale drilled easily but became more bed in depth and sandstone wore away the gauge Of the bits rapidly. A room-and-pillar mining system was adopted whereby rooms turned off on 80-ft centers, each room 40-ft wide and 50-ft high. Rib pillars between rooms were cut into 100 ft lengths by frequent holes. Ventilation is achieved through the two shafts, the down-draft through the service shaft, and the return through the pr0duction shaft. The hoist has a a Of 300 tons per hour and is equipped with 10-ton balanced skips requiring. a 2-min cycle Or 30 trips Per hour- Hoisting is designed to Operate by automatic loading and no hoistman is required for normal Operation. The 48 X 60 in. jaw primary crusher is underground. It is fed through chute and chain feeders and is flood-oil lubricated and cooled. An inclined belt conveyor returns oversized material to the crusher. Tramming is by Diesel-powered trucks.

Jan 1, 1948

By R. E. Head, E. L. Tucker

Previous investigations of E. L. Tucker and R. E. Head&apos; related in particular to the effect of cyanogen compounds on galena, sphalerite, and pyrite, and their behavior in the presence of such compounds. The present contribution deals with the floatability of the copper minerals and of pyrite. All experiments were performed on minus 200-mesh material, the method of preparation being the same as that described in the previous article. Flotation tests were made in a small mechanically agitated machine of 50-gm. capacity designed in this laboratory by Gates and Jacobsen.2 General Naval Stores pine oil No. 5 and potassium xanthate were used in constant amount in all of the experiments; these agents were selected because of their present wide use in the flotation of copper minerals. Time additions were varied to secure four final hydrogen ion concentrations, namely, neutral, 0.0005 per cent. CaO, 0.003 per cent. CaO, and 0.02 per cent. CaO. The variation in lime addition was introduced to include the range of alkalinities employed in actual flotation practice. The minerals employed were the purest obtainable. Their analyses are shown in the following tabulation: Table 1.—Analyses of Minerals Employed in Experiments mineral Cu Fe Cao S MgO Insol. Chalcocite .............. 77 02 0.49 0.29 21.70 0.08 0.28 Chalcopyrite............. 34.50 29.20 0.23 34.10 0.07 1.42 Bornite................. 64.30 9.30 0.12 23.70 0.10 1.95 Pyrite....................... 36.90 1.12 49.70 .... 1.51

Jan 1, 1926

By W. A. Walker, G. W. Ostroot

An increase in the number of deep wells being drilled where extreme bottom-hole temperatures are encountered, and the anticipated drilling of wells where temperatures in the range of 500°F or higher may occur, has brought about a comprehensive investigation of cementing materials and of the techniques involved in their proper usage at these elevated temperatures. Included are developments in cements, retarders, weighting materials and other cement additives which make it possible to formulate a variety of compositions to help resolve the cementing problems of these extreme well conditions. The problems associated with the selection and testing of cements are discussed, and a resume of field results is included. Previous studies on strength retrogression indicate that caution should be exercised in the selection of a cementing composition for use in high-temperature wells. It now appears that, by the addition of silica flour as a stabilizing additive to certain cements, compositions covering a wide range of slurry densities can be designed to meet extreme well conditions without strength retrogression. Improvements in cement retarders make it possible to produce a four-hour thickening time at static temperatures up to 500°F. This temperature is considerably higher than conditions presently being encountered in drilling and completion work. Inert weighting materials, used to produce 20-lb/gal or heavier cement slurries, are reviewed. INTRODUCTION As the search for oil continues, the number of wells being drilled to depths of 10,000 ft or below has continued to increase over the past decade. During 1959, there were 50,893 wells drilled in the United States for a total of 209 million ft of hole. Of this total, approximately 4.45 per cent were drilled below 10,000 ft and 0.30 per cent below 15,000 ft, with a record depth of 25,340 ft recorded (Table 1). With the drilling of this record-shattering hole comes the question, "How deep can wells be drilled?".&apos; Limitations with respect to equipment (surface and subsurface), cementing materials and techniques would cause some concern; however, a panel of experts have agreed that the U. S. oil industry has the equipment and know-how to drill a 50,000-ft hole. The greatest deterrent would be the 700°F temperature they would anticipate encountering at this depth. Although the number of wells drilled under what is generally considered hot-hole conditions (230°F and higher) has been relatively high, each well often presents distinctly individual problems and requires separate consideration and selection of special materials, techniques and equipment. At the present time there are over 30 additives and special cements available for use in "tailoring" a cementing composition for a specific well. It is not uncommon to use three or four different additives with the basic cement to produce the desired slurry characteristics. A generally accepted procedure is to make laboratory tests on selected cementing compositions prior to pumping them into wells deeper than 12,000 ft, or where static temperatures are in the range of 260°F or higher. In some instances, it is recommended that laboratory tests be made where less severe well conditions are encountered. Prior to selecting a cementing composition for a particular well, key personnel representing the operator, drilling contractor and service company should meet to determine that each individual is acquainted with every detail which might influence cementing results and to discuss the execution of the job. For cementing hot-holes, a number of factors must be evaluated before proceeding with the operation. Consideration must be given to the following. 1. Thickening time—The slurry must remain fluid for a sufficient length of time to allow displacement down the casing and up the annular space in a primary cementing job or, in squeeze-cementing, adequate thickening time for both the build-up of a satisfactory squeeze pressure and the reversing out of excess cement. The thickening time of standard retarded cements will often be too short under extreme temperature conditions, thus involving special formulations and requiring laboratory tests to determine the proper amount of additional retarder to obtain the desired pumpability.

By L. C. Reese

The ultimate resistance against a rigid cylinder which is moved laterally in a cohesionless soil is a function of the geometry of the cylinder and the properties of the soil. An approximate method is developed for computing this resistance and is tested against results of laboratory experiments. Satisfactory agreement between the method and experiment was obtained. Not only was the ultimate resistance against the cylinder measured, but measurements were made of the shape of the rupture surfaces. These measurements should allow the development of a more rigorous computation procedure. INTRODUCTION A critical aspect in the design of offshore drilling platforms is assuring the stability of the platform during a hurricane. The large horizontal loads from waves and wind make a severe loading condition. Piles are generally employed as the foundation since they can be effective in resisting both horizontal and vertical loads. Spuds are sometimes used with a mat foundation, where the spuds are designed principally to resist horizontal loads and the mat designed principally to resist vertical loads. The research reported in this paper is related to one aspect of the problem of laterally loaded piles or spuds in sand. The complete solution to the problem of the laterally loaded pile in sand would require the prediction of soil resistance against the pile as a function of pile deflection; only the ultimate resistance against short piles is considered in this paper. A considerable amount of additional research will be necessary in order to obtain a complete solution to the problem of the laterally loaded pile in sand; however, the work reported here should be useful as a guide in the performance of some of the additional research. ULTIMATE LATERAL RESISTANCE AGAINST A LONG FALL IN SAND To aid in the understanding of the theory which is developed for a cylinder, the theory for earth pressure against a wall is reviewed. In Fig. l(a), a long wall of height H is shown embedded in soil. Soil resistance will develop as the wall is deflected, and the soil resistance will increase with deflection until some limiting value is reached. In this discussion, and those following, it is assumed that all points on the wall deflect equal amounts. A possible shape of the real curve which relates soil resistance to deflection is shown by the dashed line in Fig. l(b); however, as a means of simplifying the discussion, an idealized curve (shown by the unbroken lines) is drawn. If such a wall as this were furnishing the horizontal support for an offshore structure, the dashed curve in Fig. 1 would be the information needed in performing a foundation analysis, with the idealized curve possibly being an acceptable substitute. For the idealized curve, the soil resistance is linear with deflection for the early portion of the curve such that

By Russell A. Carter

Seven years of rising silver prices have effectively revived an historic Idaho mining district and given it a new lease on life. Initial production earlier last year from the DeLamar open-pit silver mine in southwestern Idaho ushered in a new era of mineral production in a region that has weathered boom-and-bust cycles reaching back the better part of a century.

Jan 1, 1978

By E. A. Holbrook

LOCAL yearly taxes levied on bituminous coal lands in Pennsylvania have become a cost of first importance to the coal industry of the State. In Pennsylvania there is no State tax on real estate, but local taxation of real estate furnishes the greater part of the revenue necessary for the small governmental unit, as counties, townships, boroughs, and local school, road, and poor districts. Coal in place in the ground, whether or not title thereto has been severed from ownership of the surface, is assessed as real estate and on its supposed sale or market value. There are eight classes of counties in Pennsylvania, based on population; in populous counties of the first, second and third class, assessments are made by a county board appointed by the county commissioners and are fairly uniform throughout the county. In counties of the fourth to the eighth classes inclusive, property assessments are made by property assessors elected by and for each township within a county. In these counties the board of county commissioners acts as a board of equalization and review to hear appeals. In most counties, therefore, where there is a large unmined reserve of coal, assessments on that coal vary for each township, irrespective of the fact that the coal bed is continuous under many townships.

Jan 1, 1933

By C. O. Lee, R. H. Feierabend, Z. W. Bartlett

DESPITE the fact that American brimstone production has increased 2 times since the prewar period 1935-1939, the demand for sulphur exceeds the supply. To alleviate this situation efforts are being made to increase the production of sulphur and bring the shortage to an end. The most important developments are being undertaken on the Gulf Coast. One new brimstone mine has been put into operation and three others are being developed. These projects are expected to account for a large part of the additional sulphur production now anticipated for the free world.&apos;.&apos; Except for a small amount of byproduct sulphur from sour natural gas and refinery gases, American brimstone is produced by the same process devised by Frasch 60 years ago, consisting essentially of the injection of superheated water at about 325°F into sulphur-bearing formations through wells which are drilled from the surface by standard oilfield methods. Sulphur deposits vary in depth from a few hundred feet to 2500 ft from the surface; in a typical deposit the sulphur occurs as crystalline aggregates in porous limestone and gypsum in concentrations varying from 5 to 40 pct, the thickness of the formation ranging from a few feet to several hundred.3 The deposits are usually surrounded by formations impermeable to the flow of hot water, the top and sides being enclosed by impermeable sediments and the bottom by dense impermeable anhydrite. As the hot water leaves the well bore, it percolates through the formation and transmits its heat to the rock and sulphur. When the sulphur reaches 240°F it melts, separates from the rock, and flows through the hot channels downward to the bottom of the well. Here it is freed from incoming water and from formation water, which saturates the porous rock, by gravity separation, liquid sulphur being 1.8 times as heavy as water. It then is pumped to the surface in a relatively pure state, 99.5 pct or better. Chief contaminants are organic impurities, such as petroleum residues, which are soluble in sulphur and tend to discolor it.&apos; Sixteen deposits of commercial magnitude have been discovered in the Gulf Coast area. Five of these deposits have been depleted and abandoned with production totalling more than 26,886,000 tons. Eight properties are operating and have produced 65,875,-000 tons to Jan. 1, 1952, for a total Frasch-type production of 92,761,000 tons. Three new deposits are under development. Aforementioned deposits are listed in Table I. Each of these deposits has been found in the cap-rock overlying shallow intrusive salt plugs or domes and buried in several hundred to as much as 2500 ft of sediments. All salt domes do .not contain sulphur; only 16 sulphur deposits have been found in a total of 231 salt domes which are known to exist in the Gulf Coastal states of Texas, Louisiana, Mississippi, and Alabama. Ten of the salt domes lie in the Gulf of Mexico offshore from the Texas and Louisiana coasts. Additional offshore domes may be found, but their value as a sulphur potential is questionable owing to the great hazard and high cost that can be visualized at these exposed locations where depths of water reach 50 ft. Marsh operations of Freeport Sulphur Co. are in the southeast section of Louisiana. In general, the country is low, flat, relatively uninhabited marshland broken by many shallow lakes and bayous which extend for irregular distances inland. Geologically, the coastal area is of sedimentary origin, having been built up gradually under the sea by deposition of material carried down by large streams to their deltas. Offshore bars were formed enclosing

Jan 1, 1953

By C. O. Lee, Z. W. Bartlett, R. H. Feierabend

DESPITE the fact that American brimstone production has increased 2 times since the prewar period 1935-1939, the demand for sulphur exceeds the supply. To alleviate this situation efforts are being made to increase the production of sulphur and bring the shortage to an end. The most important developments are being undertaken on the Gulf Coast. One new brimstone mine has been put into operation and three others are being developed. These projects are expected to account for a large part of the additional sulphur production now anticipated for the free world.&apos;.&apos; Except for a small amount of byproduct sulphur from sour natural gas and refinery gases, American brimstone is produced by the same process devised by Frasch 60 years ago, consisting essentially of the injection of superheated water at about 325°F into sulphur-bearing formations through wells which are drilled from the surface by standard oilfield methods. Sulphur deposits vary in depth from a few hundred feet to 2500 ft from the surface; in a typical deposit the sulphur occurs as crystalline aggregates in porous limestone and gypsum in concentrations varying from 5 to 40 pct, the thickness of the formation ranging from a few feet to several hundred.3 The deposits are usually surrounded by formations impermeable to the flow of hot water, the top and sides being enclosed by impermeable sediments and the bottom by dense impermeable anhydrite. As the hot water leaves the well bore, it percolates through the formation and transmits its heat to the rock and sulphur. When the sulphur reaches 240°F it melts, separates from the rock, and flows through the hot channels downward to the bottom of the well. Here it is freed from incoming water and from formation water, which saturates the porous rock, by gravity separation, liquid sulphur being 1.8 times as heavy as water. It then is pumped to the surface in a relatively pure state, 99.5 pct or better. Chief contaminants are organic impurities, such as petroleum residues, which are soluble in sulphur and tend to discolor it.&apos; Sixteen deposits of commercial magnitude have been discovered in the Gulf Coast area. Five of these deposits have been depleted and abandoned with production totalling more than 26,886,000 tons. Eight properties are operating and have produced 65,875,-000 tons to Jan. 1, 1952, for a total Frasch-type production of 92,761,000 tons. Three new deposits are under development. Aforementioned deposits are listed in Table I. Each of these deposits has been found in the cap-rock overlying shallow intrusive salt plugs or domes and buried in several hundred to as much as 2500 ft of sediments. All salt domes do .not contain sulphur; only 16 sulphur deposits have been found in a total of 231 salt domes which are known to exist in the Gulf Coastal states of Texas, Louisiana, Mississippi, and Alabama. Ten of the salt domes lie in the Gulf of Mexico offshore from the Texas and Louisiana coasts. Additional offshore domes may be found, but their value as a sulphur potential is questionable owing to the great hazard and high cost that can be visualized at these exposed locations where depths of water reach 50 ft. Marsh operations of Freeport Sulphur Co. are in the southeast section of Louisiana. In general, the country is low, flat, relatively uninhabited marshland broken by many shallow lakes and bayous which extend for irregular distances inland. Geologically, the coastal area is of sedimentary origin, having been built up gradually under the sea by deposition of material carried down by large streams to their deltas. Offshore bars were formed enclosing

Jan 1, 1953

Discussion of the paper of JOEL H. WATKINS, presented at the New Fork meeting, February, 1915, and printed in Bulletin No. 98, February, 1915, pp. 391 to 411. H. Rims, Ithaca, N. Y.-It is interesting to contemplate to what extent the American pottery industry would be affected in case the English supply of china clay were shut off for a considerable period of time. The English deposits are very large, and are worked on a most extensive scale. They are more easily and probably more cheaply worked than our American deposits, which are of vein-like nature. The American producer of washed clay is not always as careful as the foreign miner and washer of this material, although he has improved in recent years. Our American washing plants are, furthermore, not as economical of material as it seems to me they might be, for the reason that more or less of the finest clay is often allowed to overflow, due to insufficient settling tank capacity. This fact is often shown by the milky character, of the streams into which the waste water is discharged.

Jan 5, 1915

By Marston G. Fleming

E. C. Peterson (Anaconda Copper Mining CO., Darwin, Calif.)—A study of this quite comprehensible and interesting paper by Dr. Fleming brings to mind several observations in the practical application of alkalinity and related factors to the actual practice of lead mineral flotation. Soda ash has long been a widely used and a very helpful alkaline conditioning agent in the flotation of galena from the usual run of lead-zinc ores. Soda ash is one of the common "standard" conditioning agents tried in any laboratory investigation of lead-zinc ores because it has so often proved helpful to galena flotation. However, the use of soda ash in the actual flotation of oxidized lead ores is certainly not widespread. In the flotation of certain lead-zinc ores from the Park City district of Utah, it was found in the usual cyanide-zinc sulphate-xanthate circuit that soda ash had an effect of producing a very condensed and flat froth regardless of the many frothers tried and that substitution of lime for soda ash to produce the same pH (8.0 to 8.4) improved the froth condition. However, the flotation of coarse particles of galena became so critical that some would pass through into the tailing, but caustic soda as a substitute for either soda ash or lime produced a very desirable froth condition in the same pH range and greatly improved the metallurgical outcome. Milling was carried out in typically "hard water" from watersheds of limestone and other calcareous rocks and the ore also apparently contributed magnesium and calcium salts to the pulp. Certain lead-zinc ores of Mexico have shown their greatest flotation response in circuits conditioned with sodium bicarbonate, and such actual mill use was also believed to be related to the water necessarily used in milling. On other lead-zinc ores the optimum has been obtained in actual milling treatment by use of caustic soda in both circuits of the operation. In flotation of oxidized lead ores in which sulphidi-zation is employed by addition of sodium sulphide, very high pH&apos;s exist in the flotation circuit. With the usual oxide lead ores, demanding 5 to 15 lb of sodium sulphide per ton of ore, pH&apos;s in the circuit (closed and open water-circuits) may range from 9.5 to 12, and for ores that contain much anglesite or a high percentage of iron oxide minerals, sodium sulphide consumption may reach as much as 30 lb per ton of ore and the resultant pH will be correspondingly higher. Yet in such flotation treatment employing either xanthate or oil (high-sulphur crude oil or diesel oils) as the collector, satisfactory to excellent grades of concentrate and lead recovery are obtained. Although there have been great studies and accomplishments in the investigations of flotation fundamentals and flotation theory, and although an investigation to determine the effect of all factors entering into the actual plant flotation of sulphide and oxide ores must become very complicated, as Mr. Fleming has mentioned in his caution regarding the drawing of general conclusions for other ores, it seems that it would be of greater interest if the techniques and investigations could, with time, approach the conditions of actual practice and lead the way to improved and more efficient flotation plant performance. Marston G. Fleming (author&apos;s reply)—The gulf between fundamental flotation research and plant operation is, perhaps, less wide than Mr. Peterson suggests. For example, the work described in my paper developed from an extensive investigation of a complex lead-vanadium ore from southwest Africa. This investigation started as a standard ore-testing problem but, at almost every stage, results were obtained which could not be interpreted in terms of previous experience. A program of fundamental research was therefore undertaken and was closely interlocked with the ore testing. This coordinated investigation resulted in a flotation process which has now been proved by two years of successful plant operation, and although the grade and mineralogical constitution of ore as well as smelter requirements have altered more than could have been anticipated, our knowledge of the fundamental character of the problem has made it possible to meet each change in conditions with much more confidence than would have been the case had we neglected this aspect of the investigation.

Jan 1, 1954

By V. Jares

DESPITE the fact that a combination of metals-aluminum-zinc-tin, and sometimes aluminum-zinc-cadmium-is extensively used for aluminum solders, as well as for die-castings, the constitution of these alloys has not yet been made clear. I. BINARY SYSTEMS The system aluminum-zinc is the basis of the ternary alloys under consideration. Their composition was made sufficiently clear by the investigations of Rosenhain and Archbutt,1 Bauer and Vogel,2 Sander and Meissner,3 Hanson and Gayler4 and Isihara.5 Only the temperature of decomposition of the crystals 0 seems still to be doubtful, whether it is considered as a compound of Al2Zn3 (according to Bauer and Vogel) or as an intermediate phase of variant composition (according to Hanson and Gayler). This temperature is given by most of the authors as in the neighborhood of 256° C., only Isihara giving 280° C. As its accurate determination is of special importance in the study of the ternary alloys under consideration it was experimentally controlled in the following manner: An alloy corresponding in composition to the formula Al2Zn3 was made, in which the temperature effect was found to be the greatest. This was drilled and a silver-constantan thermoelement inserted into the cavity so as to be in direct contact with the alloy. The whole was then very slowly heated and the heating and cooling curves determined. The transition temperature from the heating curve was found to be 281° C., whereas from the cooling curve it was 252° C.

Jan 1, 1927