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By J. Peperakis

Coal mine bumps are normally associated with pillar mining under moderate or deep cover. Severe bumps at Sunnyside, however, have not been confined to pillar lines. Many have occurred in virgin development and in localities a long way from active pillar workings. As early as 1918 bumps in virgin territory were attributed to the faulted structure in the Sunnyside area.' Sunnyside is an old property, mined for more than 60 years. Both man-made and natural conditions contribute greatly to bump occurrences, and loss of life and great destruction of workings have resulted from some unusual bumps in recent years. Before Kaiser Steel acquired the Sunnyside Mines in 1950, about 21 million tons of coal had been extracted. Large areas had been worked out and equally large areas first-mined. As demand for coking coal gradually diminished, extensive blocks were shut down, and during the low production period of the 1930's mining on a very limited scale was confined to a section of the property close to the coal tipple. Following purchase of the property Kaiser Steel developed the mines into a fully modernized operation. The worked out and first mined areas covered about four square miles extending five miles along the strike and up to one and a half miles down dip from the outcrop. The sections with favorable mining conditions and clean coal had been largely extracted under the selective mining system imposed by economic conditions and the lack of cleaning plant facilities. Large reserves remained on the fringes of the worked out sections and in areas under deep cover and difficult roof. There were also considerable reserves in first-mined areas. In recent years much of Sunnyside's daily output of 7000 to 8000 tons has been derived from the partially mined localities. Many bumps have occurred when pillars have been pulled within the first-mined areas and on the fringes. The bumps have been associated with retreating pillar lines backing up against old workings and pillar lines in old first-mined areas backing up against highly stressed oversized barrier pillars surrounded by smaller pillars. In some parts of the property the upper Sunnyside seam was extensively worked in the past, and sizable areas of old works overlie the present lower seam workings. Abutment pressures from barrier pillars and pillar remnants are transmitted to the lower seam, contributing to bumps and squeeze conditions. Cover: The terrain is exceedingly rough, and cover varies considerably over relatively short horizontal distances. For example, at No. 1 mine the 2000-ft cover line is ony 2700 ft from the coal outcrop, and at No. 2 mine the cover over the main hoisting slope increases from 1000 to 2000 ft in a horizontal span of 1200 ft. Cover over the present mining sections ranges from several hundred feet in the valleys to 2500 ft under the crest of the divides. A short distance ahead of Sunnyside's deepest development down dip the cover reaches 3000 ft or more.

Jan 1, 1959

By L. C. McCabe

This paper is a progress report on a study of the distribution of the banded ingredients (Figs. 1 and 2) in Illinois screenings and the method of determining their distribution. Proximate analyses and screen tests1 have been reported and a further report on the washability characteristics of the screenings is in preparation. The microscopic study of the screenings is not yet far enough advanced to permit a conclusive report on the effect of mining, screening and washing on the distribution of the banded ingredients in the coals of Illinois. However, considerable fundamental data have been collected as a background for the screenings investigation and for a proposed study of fuels composed of known quantities of vitrain, clarain and fusain, the three common banded ingredients of Illinois coals. These fundamental data and the preliminary information now available from the microscopic study of screenings are broadly indicative of the reaction of the coals to the physical processes affecting them in mining and preparation. Proximate analyses of samples of vitrain, clarain, and fusain from several Illinois mines have been published2, but those given in Table 1 serve to show the differences that are apparent in proximate analyses. The vitrain samples are consistently low in ash, and the unit-coal value is uniformly lower than in clarain. The average fuel ratio (F.C./V.M.) of the vitrain samples in the table is 1.57 whereas the clarain average is 1.42. The fusain analyses vary considerably in ash and moisture. In the two samples from this mine the moisture values range from 8.99 to 22.80 and the ash from 4.86 to 16.91 per cent. Fusain has higher fixed carbon than either vitrain or clarain but the percentage is erratic from sample to sample. The relative proportions of the banded ingredients in the Herrin (No. 6) coal in Illinois is reasonably well known but detailed information

Jan 1, 1936

By L. C. McCabe

This paper is a progress report on a study of the distribution of the banded ingredients (Figs. 1 and 2) in Illinois screenings and the method of determining their distribution. Proximate analyses and screen tests1 have been reported and a further report on the washability characteristics of the screenings is in preparation. The microscopic study of the screenings is not yet far enough advanced to permit a conclusive report on the effect of mining, screening and washing on the distribution of the banded ingredients in the coals of Illinois. However, considerable fundamental data have been collected as a background for the screenings investigation and for a proposed study of fuels composed of known quantities of vitrain, clarain and fusain, the three common banded ingredients of Illinois coals. These fundamental data and the preliminary information now available from the microscopic study of screenings are broadly indicative of the reaction of the coals to the physical processes affecting them in mining and preparation. Proximate analyses of samples of vitrain, clarain, and fusain from several Illinois mines have been published2, but those given in Table 1 serve to show the differences that are apparent in proximate analyses. The vitrain samples are consistently low in ash, and the unit-coal value is uniformly lower than in clarain. The average fuel ratio (F.C./V.M.) of the vitrain samples in the table is 1.57 whereas the clarain average is 1.42. The fusain analyses vary considerably in ash and moisture. In the two samples from this mine the moisture values range from 8.99 to 22.80 and the ash from 4.86 to 16.91 per cent. Fusain has higher fixed carbon than either vitrain or clarain but the percentage is erratic from sample to sample. The relative proportions of the banded ingredients in the Herrin (No. 6) coal in Illinois is reasonably well known but detailed information

Jan 1, 1936

By John Chipman, A. M. Samarin

It has been long known that the gas evolved during the boil in the open-hearth furnace is mainly carbon monoxide associated with smaller quantities of other gases. A number of attempts have been made to determine the precise effects of carbon and oxygen content of the bath, and of other factors, such as temperature, upon the evolution of carbon monoxide. In his investigation of the carbon-iron oxide product in liquid steel, Hertyl showed that the value of this product at equilibrium could be approximated by plotting the value of the product observed in open-hearth reactions against rate of carbon elimination, and extrapolating to zero rate. The results of this study showed a slight but definite effect of temperature upon the carbon-iron oxide reaction. Experimental studies of the evolution of gases from rimming-steel ingots have not yet attained the degree of precision necessary for an exact understanding of the effects of pouring temperature, carbon content, and iron oxide in the metal upon the composition of these gases. Klinger2 showed that the gas consists mainly of carbon monoxide, and that considerable variation in its composition occurs during the solidification of the ingot. In order that these variations may be understood in their proper relationship to the progress of solidification of the ingot and the segregation that accompanies solidification, it is essential to have a knowledge of the condition of equilibrium in the several chemical reactions by which the gases are being formed. It is also necessary to understand the effects of temperature upon the equilibria, and further, to know the manner in which the temperature of the liquid metal within the ingot changes as the skin of the ingot is being built up. The reactions in which we will be chiefly interested are those involving in the one case the oxides of carbon, and in the other case steam and

Jan 1, 1937

By George W. Maynard

In the death of Sir William Siemens, the Institute loses its most distinguished honorary member, one who, without exaggeration, may be ranked among the greatest Men of the century. In justification of this claim, I quote in part the words of two other men eminent in the walks of science. Professor Huxley, addressing the Royal Society, spoke of Siemens as "a marked example of vast energy, large scientific acquirements, and intellectual power of a high order," and as one " who had no superior in fertility and ingenuity of invention, while hardly any living man so thoroughly combined an extensive knowledge of scientific principles with the power of applying then] in a commercially successful manner. The value of his numerous inventions must be measured, not merely by the extent to which they have increased the wealth and convenience of mankind, but by the favorable reaction on the progress of pure science which they, like all such inventions, have exerted, and will continually exert." Dr. Wedding, in his address before the Verein zur Befarderung des Gewerbefleisses in Preussm, speaks of Siemens as being "so fortunate as to combine German erudition with British activity in such a manner that both nations, Gertnan as well as English, were equally proud of him; and, now that his rich life is ended, regret is expressed on both shores of the North Sea, first by the Germans that his entire life had not been spent in Germany, and his powers dedicated to Germany, and by the English that he was not born a Briton." Germany may well be proud of being the birth-place, not only of such a man, but of such a family; for where in history shall we find in a single family such a wide range of knowledge so successfully applied to the arts? The least distinguished name in the following list has added to the world's knowledge enough to satisfy the desire for fame of any ordinary man. This constellation is made up of:

Jan 1, 1884

By William L. Grube

PECIMEN preparation for electron metallography involves several steps, such as polishing, etching, replicating, mounting, and shadowing. Although each step must be done with care, the operation requiring the utmost attention is etching. Proper etching is important because the relief pattern developed on the surface of the specimen by the etchant, and reproduced as minute differences in thickness of the replica, determines entirely the amount of detail seen in the final micrograph. The characteristic colored stains, sometimes used in light metallography to simplify identification of certain microconstituents, cannot be tolerated because there is danger of introducing artifacts in the replicating operation. It is also quite difficult to remove plastic replicas from stained specimens. A suitable etchant for electron metallography must, therefore, in all cases exhibit a preferential attack upon each of the microconstituents present sufficient to result in a difference in surface elevation. When only two microconstituents are present, it is not too difficult to find a suitable etchant since their physical or chemical properties are generally sufficiently different to result in a marked difference in attack by the etchant. For example, picral (a saturated solution of picric acid in methanol used as an immersion etch) is a satisfactory etchant for the specimen shown in Fig. 1 consisting of iron carbide particles embedded in a ferrite matrix.'

Jan 1, 1952

By H. W. Schull

The Alligator Ridge gold deposits are located in northwest White Pine County at the southwest end of Alligator Ridge. Alligator Ridge is on the west side of Long Valley in the range of hills that separates Long and Newark valleys. The nearest population center is Ely, about 113 km (70 miles) to the southeast. Access to the Alligator Ridge gold mine from Ely is via US Highway 50 and the Long Valley Ruby Marsh Road. The latitude and longitude is approximately 39° 45' north and 116° 30' west. The Alligator Ridge gold deposits occur in the lower 61 m (200 ft) of the Mississippian-Devonian Pilot Shale formation, a laminated calcareous carbonaceous siltstone. The gold deposits contain carbonaceous, oxide, and jasperoid type gold ore. For more details on the geologic features of the deposits, see Schull, Sutherland, and Ilchik (in press). The discovery story of Alligator Ridge began in the spring of 1976 when the areas mapped as jasperoid on the 1:250,000 scale geologic map of White Pine County (Hose and Blake, 1976) were examined and sampled. Seventeen samples, about 23 kg (50 lb), were collected from an area about 0.65 km2 (0.25 sq mile). Of these 17 samples 10 reported atomic absorption values of less than 0. 1 ppm Au and 7 reported values in the 0.1 to 1.0 ppm Au range. In June of 1976 20 lode claims were staked to claim the area of the rock chip sampling. The claims' end and side center lines were used as a grid for soil sampling. Sample stations were 91 m (300 ft) apart and sample lines were 229 m (750 ft) apart. The samples were sieved to - 180 µm (- 80 mesh). Out of 99 soil samples, seven samples reported Au values in the 0.1 to 1.0 ppm range. Of the seven auriferous samples, five were located over the jasperoid outcrops previously sampled; one over unmineralized Pilot Shale a few hundred m (ft) downslope from some Au-bearing jasperoid; and one from a 15 x 15 m (50 x 50 ft) talus outcrop area of hitherto unnoticed mineralized Pilot Shale. Subsequent sampling, mapping and drilling would show that this 15 X 15 m (50 x 50 ft) outcrop area was the top of the Vantage 1 ore body, about 1.27 Mt (1,400,000 st) of over 3 g/0.9 t (0.11 oz/st) Au. Late in the summer of 1976 about 30 more 1.4 to 2.2 kg (3 to 5 lb) rock chip samples were collected in the course of preliminary geologic mapping. This mapping and sampling showed that the gold-bearing jasperoids occurred at the contact between the Pilot Shale and the underlying Devils Gate Limestone. Rock chip samples of 0.1 ppm Au or greater were restricted to the jasperoids and the mineralized outcrop area of Pilot Shale located by the soil sample survey. Rock chip samples from the area of mineralized Pilot Shale were in the 3 to 5 ppm Au range. Activity resumed in the summer of 1977 with a more detailed soil geochemical survey. The jasperoid areas were defined as large geochemical gold anomalies of values greater than 0.1 ppm and locally greater than 0.2 ppm Au. Soil samples from the area of mineralized Pilot Shale outlined a greater than 0.1 ppm gold anomaly 61 x 152 m (200 x 500 ft) in size. Further geologic mapping showed that elsewhere, even where bleached and silicified, the Pilot Shale areas were geochemically very low in gold (less than 0.1 ppm Au). In November, 1977 twelve rotary percussion drill holes were drilled to test the gold-bearing jasperoid areas and the mineralized Pilot Shale area. Drilling of the jasperoid areas showed that the jasperoids gave way at shallow depths [less than 24 m (80 ft)] to unmineralized unaltered Devils Gate Limestone. A five hole cross pattern was drilled to test the area of mineralized Pilot Shale. Four of the five holes re-

Jan 1, 1985

By H. K. Martin

IN September 1954 the Lavender pit concentrator at Lowell, Ariz., began treating low grade porphyry copper ore from the nearby Lavender mine. Nominal capacity of the mill is 12,000 tpd, but production now averages 16,226 tpd. Plant design was somewhat affected by the re-use of old equipment and the substantial re-use of old buildings. A breaking-in period between June 24 and Sept. 1, 1954, was devoted to training operators and making minor changes in launders, chutes, and piping. From Sept. 1, 1954, to July 1, 1956, the mill treated 8,598,105 dry tons of ore, from which 556,541 tons of concentrate were produced, containing an indicated 144,055,185 lb of copper.

Jan 11, 1957

By E. M. Wise

The practice of adding moderate quantities of nickel to a variety of bronzes has been employed by foundrymen for many years with several objects in view. In some instances it was desired to harden the alloy; in others it was to increase the fluidity or to improve the solidity of the castings, or to refine their grain. These important matters have been considered in detail by Pilling and Kihlgrenl and by numerous other workers cited by them, and with the exception of the first will not be considered in the present communication. The possibility of reducing the cost of bronze by replacing a portion of the tin with nickel received attention some years ago by Burgess and Woodward12 and, as will be shown later, offers attractive savings in cost under present conditions. The age-hardening characteristics of the nickel bronzes of appropriate compositions have been known for some time and were mentioned by Price, Grant and Phillips3 and discussed by Wise4 in connection with their paper. These matters are further considered in recent patents15 and are becoming of commercial importance in the production of high-strength castings. The equilibrium relations existing in the high-copper region of the copper-nickel-tin system have been carefully studied by Eash and Upthegrove,6 and in somewhat less detail by Veszelka.7 The observa-

Jan 1, 1934

By M. R. Geer, J. D. Davis, H. F. Yancey

ALTHOUGH the mechanical cleaning of coal is carried out at plants on the surface, preparation is actually begun at the face in the mine. Here the character of the coal and the amount, character, and distribution of the impurities within the bed may be seen. Blasting methods, dust-allaying procedures, location of mining cut with respect to bands of impurity, and the practice of discarding segregated impurities underground, all have an important bearing on the successful operation of surface cleaning units. The most important single characteristic of both coal and its associated impurities from the standpoint of cleaning is specific gravity. Other characteristics related in one way or another to the preparation of coal are rank, petrographic composition, structure and hardness, and friability. These and still other coal properties are discussed in the first section of this chapter and impurity characteristics in the second. COAL CHARACTERISTICS RELATED TO PREPARATION Rank As a result of work done over a period of several years by committees of the American Society for Testing Materials and the American Standards Association, standard specifications are now available showing the classification of coals according to rank and quality of grade. The term "rank" expresses the degree to which the original coal-forming material has been changed by metamorphism through successive stages from peat to anthracite. Table 1 shows the classification of coals according to rank as devised by the committees of the organizations mentioned. The basic scheme of classification for the higher-rank coals is according to fixed carbon content, calculated to the dry, mineral-matter-free basis. Groups of lower rank are divided

Jan 1, 1950

By L. W. Holm

Laboratory flooding experiments on linear flow systerns indicated that high oil displacement, approaching that obtained from completely miscible solvents, can be attained by injecting a small slug of carbon dioxide into a reservoir and driving it with plain or carbonated water. Data are presented in this paper which show the results of laboratory work designed to evaluate this oil recovery process, particularly at reservoir temperatures above 100°F and in the pressure range of 600 to 2,600 psi. Under these conditions CO2 exists as a dense single-phase fluid. It was found that a bank, rich in light hydrocarbons, was formed at the leading edge of the CO? slug during floods on long cores. Formation of this bank is probably due to a selective extraction by the C02 and, it is believed, partially accounts for the attractively high oil recoveries. In crddition to the efficient displacernerlt of oil from the pores of the rock by this process, the favorable rnobility ratio related to a C0 2-water flood also contributes to high oil recovery. A further advantage of this process is noted on limestone and dolomite rock, in that the CO1 reacts with the porous medium increasing its permeability. Flooding experiments were conducted on sandstone and vugular dolomite models. The results of this experimental work show the effect on oil recovery of type of porous medium, pore geometry, flooding length, and flooding pressure. The porosity of the cores and rilodels varied from 16 to 21 per cent and their pern~eabilities ranged from 100 to 200 md. A reconstituted West Texas reservoir oil, a West Texas stock tank oil, an East Texas stock tank oil and Soltrol were used to represent reservoir oils in this study. Oil recoveries ranging from 60 to 80 per cent of the original oil in place in these cores were obtained by CO2,-carbonated water floods at pressures between 900 and 1,800 psi, compared with conventional solution gas drive and water-flood recoveries of 30 to 45 per cent on the same cores. Oil recoveries greater than 80 per cent resulted frorn f1oods at pressures above about 1.800 psi. There high recoveries were noted from both the sandstone and the irregular Porosity carbonate cores. In all floods, additional oil was recovered by a solutiorr gas drive resulting from blowdown following the flood. Oil recoveries of 6 to 15 per cent of the original oil in place were obtained during this blowdown period. This additional recovery was found to be a function of oil remaining after the flood, decreasing with decreasing oil saturation. It was also noted that highest oil recoveries by blowdown were obtained when carborlated water rather than plain water followed the CO, slug. INTRODUCTION Miscible phase or solvent flooding processes, which are designed to increase oil recovery -from petroleum reservoirs, involve the injection of small quantities of a petroleum solvent into the reservoir, followed by an inexpensive scavenging fluid which is miscible with the solvent. Essentially complete displacement of oil from the pores of reservoir rock has been obtained by this technique. CO,, although not completely miscible with most reservoir oils at moderate pressures, is highly soluble in these oils at pressures above about 700 psi; there is appreciable swelling and reduction in the viscosity of oil when CO, is dissolved in it. Therefore, CO, could be expected to perform similarly to other oil solvents as a displacing agent. CO, is also highly soluble in water at elevated pressures, so water should be a satisfactory material to drive a slug of CO, through an oil-bearing reservoir. A favorable mobility ratio would be obtained through the reduction in viscosity of the oil and the use of water as a final displacing agent. A number of investigations of the use of CO, to improve oil recovery have been reported in the literature.2,3,4,5,6 These studies, however, have been conducted on uniform porosity sandstone at relatively low temperatures and pressures. The behavior of CO1 as a flooding agent at temperatures above its critical temperature could not be predicted adequately from these studies, particularly for the case of non-homogeneous rock. The purpose of this work was to evaluate the oil recovery efficiency of a process involving the injection of a CO2 slug followed by carbonated water, at reservoir temperatures above 100°F and in the pressure range of 600 to 2,600 psi, and to compare this process with conventional water flooding. The investigations were primarily designed to provide information on the efficiency of the process in irregular porosity carbonate rock. The effects of flooding path length, the presence of free gas, the type of oil to be recovered, and the amount of solvent required were also determined. The essential results of static phase behavior studies and experimen-

By D. W. Fuerstenau, G. D. Gumtz

Use of the discretized batch-grinding model for the simulation of locked-cycle grinding tests from batch-grinding data is illustrated. The simulated results were compared with actual locked-cycle experimental data for the dry grinding of dolomite. To illustrate the utility of this simulation method, a number of relationships between operating and performance parameters were generated, including relations between batch grinding and the Bond test, the production rate and the circulating load, and the production rate and the product size. A large amount of testing is done each year in the mineral industry for use with grinding unit cperations, and much of the experimental test data is obtained by the tedious locked-cycle testing procedure. In addition to being experimentally complex and requiring large amounts of sample, the very nature of the locked-cycle experiment yields results that cannot readily be interpreted. The attempts that have been made to model comminution systems during the last few years may provide a better and simpler way to obtain and analyze grinding test data; these models involve elements of both fitting to "model equations" and deterministic representations.1-1 The traditional engineering design techniques for comminution systems have relied mainly upon large amounts of industrial operating data that have been correlated with locked-cycle grinding data.',' Bond's empirical mill-design procedure involving locked cycle testing remains the most generally available method to this day. The purpose of the present paper is to show how much more useful data can be obtained from a simple batch-grinding experiment that provides information which subsequently can be utilized with population balance models of the grinding process to simulate locked-cycle behavior. These simulation results can, of course, be used in Bond's general design scheme. However, the combination of batch-grinding tests and the population balance model allows many more conditions to be considered than do single laboratory tests under specific locked-cycle conditions. The use of these simulation techniques for prediction of locked-cycle behavior represents one of the first practical applications for the simulation method in comminution.

Jan 1, 1971

Page Bronze Bearing Metals. By G. H. Clamer............... 162 Pennsylvania Railroad Anti-friction and Bell Metals. By F. M. Waring .. 166 The Tin-plate Industry. By D. M. BUck. Discussed by G. H. ClameR, J. W. RICHARDS............................ 168 The Aluminum Bronze Industry. By W. M. Corse............ 171 Bronzes, Bearing Metals, and Solders. By G. K. BURgess and R. W. Woodward. Discussed by G. H. Clamer, R. T. Roberts......... 175 Babbitts and Solder. By G. W. Thompson................ 184 The Cadmium Supply of the United States. By C. E. Siebenthal. Discussed by M. L. Lissberger, C. W. Hill, F. F. ColcoRd.......... 185 Solder, Its Use and Abuse. By M. L. LissbergeR............ 192 Bronze Bearing Metals G. H. ClameR,* Philadelphia, Pa.—Unfortunately, prior to the war no serious attention was given to the conservation of tin, notwithstanding that this country is practically dependent upon outside sources for its entire tin supply. Tin is of vital importance in many industries, but it is surprising how many and how excellent are its substitutes when we become acquainted with them. Tin has always been a relatively high-priced metal, and it is part of the human attitude to associate high prices with high standards; it is not until the price of a commodity becomes well-nigh prohibitive that we hunt for substitutes, because the idea of substitution seems always to involve an assumption that the substitute must necessarily be inferior. The history of the development of bearing bronzes is a striking example of this policy. In the early days, copper-tin alloys were almost universally used, the idea then being prevalent, which is still held by many, that a bearing to resist wear must be hard, and the harder the better. The favorite bronze bearing contained 90 per cent. copper and 10 per cent. tin; frequently, in service which was considered severe, even higher proportions of tin were used. Such hard alloys have great resistance to compression, but as a rule they had a very wide factor of safety in this

Jan 1, 1919

By Jack White, Ralph B. Adair

The Mufulira mine in Northern Rhodesia is 13° south of the Equator and at an altitude of 4100 ft above sea level. The concentrator was planned in 1930 to treat about 10,000 tons of ore per day, but before construction work had gone very far the size of the plant was reduced to 1500 tons daily capacity. Then just as the construction was finished in December 1931, the price of copper did not warrant the commencement of operations and it was not until October 1933 that the mine re-opened. Extensions have been made to the plant in 1934, 1935, 1936, 1937, 1940 and finally in 1945. The capacity of the plant when the 1945 extension is completed will be 9500 short tons per day. The various extensions have been carried out with the minimum confusion and with great skill on the part of the designers and the erection engineers. In dealing with the plant in this paper it is proposed to give an outline of the present practice and only to refer to past practice when it is considered of particular interest. Ore Treated The ore consists of fine grained highly siliceous, felspathic and argillaceous quartz- ites, the latter containing graphitic carbon and locally termed graywacke. These rocks are considerably altered near the surface and on the fringes of the ore body. Despite extensive efforts at mixing, both underground and in the crushing plant, many sudden changes of ore take place in the mill feed. The minerals are chalcocite, bornite and chalcopyrite with relatively unimportant amounts of malachite, native copper, azurite, covellite and chrysocolla. Gold is present at about I oz to a thousand tons, and silver at about 2 dwt. per ton. With increasing depth the nonsulphide content or,, as commonly termed locally, the oxide content of the ore is decreasing and is now less than 0.25 pct against a high of 0.77 pct- Crushing Operations The first stage of crushing is done under. ground where the oversize from I2-in. grizzlies is fed to a 56 X 72-in. jaw crusher. At the Selkirk shaft two 10-ton skips deliver the run of mine ore at a rate of 450 tons per hour to the 400-ton capacity shaft bins. One 6 ft wide Ross chain feeder and one locally made air-operated finger feeder feed the two 30-in. McCully crushers. Ahead of each crusher is a 6 X 9-ft spring grizzley spaced at 5 in. on a 35O slope. Neither the Ross chain feeder nor the finger feeder is entirely satisfactory and for the wet, muddy and sticky ore that has to be handled it is planned to replace these with two 6-ft wide apron pan feeders. The McCully crushers deliver a minus 5-in. product, at a.rate of over 500 tons per

Jan 1, 1949

By D. B. Hunter, H. W. Rosenberg

The titanium-rich portion of the Ti-Pd system was investigated from 0 to 75 wt pct Pd by metallo-graphic and X-ray techniques. A 0 eutectoid occurs at 24 wt pct Pd and 1190°F. Two compoutzds are indicated in the region below 75 wt pct Pd, Ti,Pd and Ti2Pd3. The solubility of palladium its a titanium is low, probably less than 1 pct. In 1960 Rudnitskii and Birunl published a complete version of the Ti-Pd phase diagram. However, their work was in disagreement with the earlier literature in that they reported only one inter metallic compound, whereas three had been reported earlier. In view of these discrepancies, it was therefore necessary to redetermine those portions of the diagram of immediate interest. The following account describes our work on the system over the range of 0 to 75 wt pct Pd. MATERIALS AND METHODS Distilled titanium sponge and elemental palladium were used in the formulation of the alloys; the chemistry of these materials is detailed in Table I. The alloys were prepared as 10 to 50 g blended compacts that were melted into buttons by arc melting under gettered argon on a water-cooled copper hearth. Weighing of the ingredients before and after melting showed that negligible weight changes occurred. Therefore, no analyses were undertaken and the compositions of all alloys are nominal. All alloys were fabricated by hot rolling at 1700°F to 0.070-in.-thick sheet. Scale was removed by sandblasting and pickling in a 5 pct HF-35 pct HNO,, balance H20 solution. For metallographic examination, specimens were mounted after heat treatment transverse to the rolling direction, ground on silicon carbide papers of increasing fineness to 600 grit, and then electro-polished using a solution containing 600 ml me-thanol, 60 ml perchloric acid, 360 ml butyl cello-solve, and 2 ml "Solvent X". Unless otherwise specified, etching of alloys containing up to 42 pct Pd was carried out by swabbing with a 12 pct HN03-1 pct HF aqueous etch where a bright etch was required, or by a 1 pct hydrofluoric in saturated oxalic acid solution where contrast between phases was required. The Ti-52.8 Pd alloy was etched with a solution of 25 ml HF, 40 ml glycerine, 35 ml methanol, and 18 g benzalkonium chloride. For X-ray examination, 1/2-in.-square speci- mens of sheet were mounted flat in a standard 1-in. metallographic mount and ground and polished as above. X-ray diffraction was performed using a Norelco type 12045 Diffractometer, employing CuKa radiation with a nickel filter at 40 kv and 20 ma. Specimens were rotated about the sheet normal during exposure. Although this procedure did not remove the effects of sheet texture from the relative intensities, it had the advantage that oxidation or contaminants entering during preparation of powder samples could not confuse the patterns obtained. RESULTS AND DISCUSSION Fig. 1 illustrates the Ti-Pd phase diagram according to Rudnitskii and Birunl with the work of the present authors superimposed. Both interpretations agree that the system is of the 0 -eutectoid type with an extensive 0-phase field, and that the eutectoid temperature is just below 1200°F. There is also agreement that the solubility of palladium in a titanium is restricted. Our work would indicate that the a solubility of palladium is low, probably less than 1 pct. However, whereas Rudnitskii and Birunl place the eutectoid composition at 41 wt pct Pd, this investigation shows it to be at about 24 wt pct Pd. Moreover, this investigation confirms the existence of compounds at Ti2Pd and Ti2Pd3, whereas Rudnitskii and Birun report only a single Berthol-lide phase covering the TiPd to TiPd, range. Laves et a1.' and Wallbaum, whose work was summarized by Maykuth , reported the existence of Ti2Pd3 and TiPd, in addition to Ti2Pd. More recently, Nevitt and Downe~' have reported the structure of

Jan 1, 1965

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

Jan 1, 1955

By Charles White Merrill

Money is one of the most pervasive elements in human life. The compensation for a workman's daily efforts is expressed as a wage and is measured in money. What an individual may consume depends largely on his income which also is expressed in terms of money. If he would start an enterprise its size would be determined in large part by the amount of money available for capitalization and its success would be measured in net income expressed in money. In short, the most widely used common de- nominator for comparing merchandise, real property, jobs, enterprises, gross national product, or personal success is money. Despite this use of money by almost everyone past infancy to express his appraisal of the innumerable values he sees around himself, the complexity of the device called money makes its nature and workings a mystery to most users. Some of the difficulty in understanding money results from the fact that it has three distinct but interrelated functions: (1) a medium of exchange, (2) a unit of account, and (3) a store of value. In many statements about money the discussion moves from one function of money to another without the speaker or the listener recognizing the changes. For example, the housewife says "We took the money we had saved up to make the down payment and after twelve monthly payments the television will be ours." When this housewife spoke of "saving up the down payment" she referred to money in its function as a store of value; when she spoke of "the down payment" she was using money as a medium of exchange; and when she referred to the "monthly payments" she spoke of money as a unit of account. Another cause of confusion in understanding money is its paradoxical nature in that it represents both the power to produce and the power to consume. For example, when the rich uncle dies one nephew may regard his inheritance as an opportunity to buy a farm and leave the ranks of the wage earners to become an independent producer, whereas the other nephew may regard his portion as the means of living in complete leisure as a pure consumer.

Jan 1, 1964

By C. P. Karr

FOR several years, the Bureau of Standards has been working in cooperation with an Advisory Committee on non-ferrous metals on various phases of the production and testing of zinc bronzes. The work has dealt, especially with the type of metal known as "Admiralty bronze" in England and as "Government bronze" in this country and consisting of 88 copper, 10 tin, and 2 zinc. Several reports have been made on this subject and these should be considered in connection with this paper.1 FIRST SERIES OF FIVE FOUNDRY TESTS A very brief summary of the first series of five foundry tests has been made,2 but for the sake of clearness the results are given here in different form. The five foundries cooperating in this investigation were: Ohio Brass Co., Mansfield, Ohio; Titanium Alloy Mfg. Co., Niagara Falls, N. Y.; Packard Motor Car Co., Syracuse, N. Y.; National Cash Register Co., Dayton, Ohio; Bureau of Standards, Washington, D. C. The object of the work was to determine whether uniform results could be obtained with this alloy in different foundries working under definite instructions. One of the participating foundries prepared, from virgin metal, a stock of ingots of the composition 88 copper, 10 tin, 2 zinc, and at the same time poured nine test bars from this melt of virgin metal. The results of the physical tests of these bars are shown in Table 1. Examination of this table shows that the highest and most nearly uniform results were obtained when the virgin metal was cast flat in chill molds and the lowest and most variable results were encountered when it was cast vertical in green-sand molds. In this, as in all other tables, the mean

Jan 9, 1919

By Thomas S. West

A gravel pack completion is described which, in addition to sand screening, permits the exclusion of water and gas from the oil production. A gravel pack composed of alternate layers of different particle sizes is employed which has horizontal but not overall vertical permeability to drilling mud. A packer is run on the tubing and set in the screen member, around which the gravel layers are placed. The hydrostatic pressure of a mud column prevents the entry of fluid above (or below) the level of the packer. The producing level may be changed by raising or lowering the tubing. Vertical coning is controlled by replacing the mud column with oil and continually injecting oil into the sand section above (or below) the packer. Three well histories with this completion are described in detail. Statistics on the first 100 completions of this general type are given. INTRODUCTION Gravel pack type completions have heretofore been almost exclusively for the purpose of preventing sand production. This paper describes and presents well data on a gravel pack procedure which is primarily a selective completion method. Although complete sand screening is achieved, the exclusion of gas and water is the primary objective. The application of this procedure is therefore not limited to unconsolidated sands. Application to hard sand or limestone reservoirs is equally feasible. GRAVEL PACK PROCEDURE Figs. 1 and 2 illustrate the gravel pack procedure employed. The gravel is placed by means of the frangible disc type dump bailer shown by Fig. 1.' This bailer has its lower end closed by a plate glass or steel rimmed cement disc. This disc breaks when the bailer passes over the liner allowing the gravel to be deposited around the liner. The liner employed is usually 2 3/8 in. to 2 7/8 in. OD and 1.995 in. or 2.07 in. ID (ID of 2-in. tubing or 2-in. line pipe). Two tvDes,. of slotted sections have been employed. One type employs horizontal hacksaw cut or milled slots of about 1/32 in. width opposite the producing section. The other type employs the same type,. of horizontal slot. but slots are placed in groups of six at intervals of about 8 in. A cage composed of half round vertical bars, spaced apart, is then welded to the pipe over the slotted sections. This liner has the bottom end closed, usually by bull plugging. The upper end is closed, while placing the gravel, by a cap which is held in place by means of a shear pin. This cap has a mandrel attached to it which extends downward inside of the liner to within a few inches of its lower end. The top of the liner cap is formed to fit a releasing type wire line core barrel overshot. The liner is lowered to bottom on the wire line by means of this overshot and released. The length of the liner is usually suffi- cient to extend to about 20 ft above the highest level to which gravel is to be placed, the upper end of the liner always being in the casing. The dimensions of the liner and bailer are such with respect to the casing size that the bailer will always pass over the liner. After releasing the liner the bailer is run to bottom. Passage of the empty

Jan 1, 1951

By Thomas S. West

A gravel pack completion is described which, in addition to sand screening, permits the exclusion of water and gas from the oil production. A gravel pack composed of alternate layers of different particle sizes is employed which has horizontal but not overall vertical permeability to drilling mud. A packer is run on the tubing and set in the screen member, around which the gravel layers are placed. The hydrostatic pressure of a mud column prevents the entry of fluid above (or below) the level of the packer. The producing level may be changed by raising or lowering the tubing. Vertical coning is controlled by replacing the mud column with oil and continually injecting oil into the sand section above (or below) the packer. Three well histories with this completion are described in detail. Statistics on the first 100 completions of this general type are given. INTRODUCTION Gravel pack type completions have heretofore been almost exclusively for the purpose of preventing sand production. This paper describes and presents well data on a gravel pack procedure which is primarily a selective completion method. Although complete sand screening is achieved, the exclusion of gas and water is the primary objective. The application of this procedure is therefore not limited to unconsolidated sands. Application to hard sand or limestone reservoirs is equally feasible. GRAVEL PACK PROCEDURE Figs. 1 and 2 illustrate the gravel pack procedure employed. The gravel is placed by means of the frangible disc type dump bailer shown by Fig. 1.' This bailer has its lower end closed by a plate glass or steel rimmed cement disc. This disc breaks when the bailer passes over the liner allowing the gravel to be deposited around the liner. The liner employed is usually 2 3/8 in. to 2 7/8 in. OD and 1.995 in. or 2.07 in. ID (ID of 2-in. tubing or 2-in. line pipe). Two tvDes,. of slotted sections have been employed. One type employs horizontal hacksaw cut or milled slots of about 1/32 in. width opposite the producing section. The other type employs the same type,. of horizontal slot. but slots are placed in groups of six at intervals of about 8 in. A cage composed of half round vertical bars, spaced apart, is then welded to the pipe over the slotted sections. This liner has the bottom end closed, usually by bull plugging. The upper end is closed, while placing the gravel, by a cap which is held in place by means of a shear pin. This cap has a mandrel attached to it which extends downward inside of the liner to within a few inches of its lower end. The top of the liner cap is formed to fit a releasing type wire line core barrel overshot. The liner is lowered to bottom on the wire line by means of this overshot and released. The length of the liner is usually suffi- cient to extend to about 20 ft above the highest level to which gravel is to be placed, the upper end of the liner always being in the casing. The dimensions of the liner and bailer are such with respect to the casing size that the bailer will always pass over the liner. After releasing the liner the bailer is run to bottom. Passage of the empty

Jan 1, 1951