Search Documents

By C. E. Webber

THE economical recovery of the valuable constituents from the effluent of gas-con-densate wells has developed into a problem of balancing the cost of recovery against the cost of compressing the residual gas back into the formation. A possible method of extracting the gasoline and distillate from the natural gas is by oil absorption at high pressures. In order to design and evaluate an absorption plant, fundamental data on the composition of the coexisting hydro-carbon vapor and liquid phases at various temperatures and pressures are essential. A review of the literature indicated that the necessary data for the design of such plants are lacking. The nearest approach to desired published data is that of Katz and Hackmuth,5 who experimentally deter-mined the composition of the coexisting vapor and liquid phases in a natural gas-crude oil system at pressures up to 3000 lb. per sq. in. and at temperatures from 40° to 200°F. This paper presents the results of the experimental determination of the equilib-rium distribution of the hydrocarbons methane through hexane between natural gas and a typical absorber oil. The ranges of temperature and pressure chosen were from 33° to 180°F. and from 100 to 5000 lb. per sq. inch.

Jan 1, 1940

In connection with the presentation of his paper in oral abstract, Mr. Hansell exhibited samples of briquettes, showing their porosity, and the change of surface produced by burning. Alfred H. Cowles, Sewaren, N. J.—I am familiar with this furnace, and I wish to point out that the larger it is, the greater is its efficiency, and the longer its life. In Europe, experiments have been made with small, short furnaces of this character, accommodating narrow cars; whereas Mr. Hansell says that there is in this country a furnace 180 ft. long .and 10 ft wide. The American furnaces, moreover, differ in design from those used in Europe; and we may expect from these larger furnaces not only greater efficiency, but also greater durability —the latter advantage being due to the fact that, in these large furnaces, projecting brick walls of greater thickness can be provided, to prevent the heat from attacking the sides of the cars, by means of bricks which, over-reaching these iron surfaces, furnish a protective cover to them. In other words, in these

Jan 1, 1913

By N. H. Parker, J. G. Papailias, G. Gutzeit

In its many forms, the turbine has greater latitude of application than any other mixing device. It is readily adaptable to all tank shapes, from the shallow pan to the tall and narrow stovepipe. Although turbine mixers can be adapted to most tank conformations, experience has shown that there is a preferred shape for optimum efficiency in each service. In the accompanying drawings this relationship is illustrated by the shallower tank for slurry suspension. The taller tank is preferable for continuous staged systems, or maximum retention of the gas phase in absorption. No single turbine covers the entire range of these applications with maximum efficiency. The back-sloped blade offers maximum power economy. The straight blade develops a higher discharge velocity for the dispersion type of service requiring localized shear. The same high shear environment is provided by the back-sloped impeller with stator ring assembly, which permits the most positive discharge control, Fig. 1. Positive stream control is critical in solids suspensions.

Mar 1, 1956

Jan 1, 1917

By R. S. Shoemaker, F. W. McQuiston

REFINERY SECURITY "Highgrading, " a polite word for stealing gold and silver, has been a way of life since the metals in native form have been mined or produced. Unfortunately, in the past, highgraders were not always severely prosecuted or even looked upon unfavorably in their communities. Recent high metal prices with attendent world wide publicity, however, has made highgrading or thievery again a serious problem in mines and plants. When a small button of gold the size of the end of ones little finger has a value equal to about one week's wages, the safe-guarding of gold production by enforcing tight security measures becomes a prime responsibility of management. The higher the gold price, coupled with unrestricted owner- ship, the greater the temptation to “get-your-cut”, and diligence by management must become an integral part of plant security. Primary security begins by knowing the expected gold production and the sampling of a gold ore mill feed for this determination has proved not reliable. However, solution flows can be accurately sampled and measured thereby closely predicting the gold recovered each day as precipitate. The progressive record of total ounces of gold contained in the precipitation press, referred to in cyanidation plants as I1solution calll1 predicts the accumulated production. The "callH is an important adjunct to security and extreme caution must be used so that the pregnant solution meter and sample are confined in a security area. It should be recognized that this key sample may be the target for Ifdoctoring" by trusted insiders (assay office employees) as a preliminary step for stealing precipitates and/or metal. Security measures similar to the following were adopted after one operation experienced a sizeable theft of gold precipitate and metal by trusted employees. The refinery area where precipitates are handled and melted to bullion and all other gold products are kept should be completely enclosed with a tight security fence preferably of solid construction. Access to this enclosure should be through one of two electrically controlled gates, one for personnel and another for occasional truck entrance. Admittance should be restricted to essential personnel who are required to sign a register in and out with the date and time. I£ there is a "back gate" to the restricted fenced area, it should remain locked except in an emergency and then opened only by a supervisor. Television monitoring cameras viewing the gate entrance and other sensitive areas connected to a viewing screen located in the general office afford visual observation at all times.

Jan 1, 1975

By William Kent

ABOUT a year ago, the writer had occasion to assist Mr. John L. Gill, Jr., of the Pittsburgh. Car-wheel Works, in making a trial of his new testing machine. A piece of Bessemer steel, of about .34 carbon, was used as a test-piece, turned to a sectional area of one square inch for a length of five inches between shoulders, and pro¬vided with large round heads, which were fitted to what is called the " Wade grip." Measurements of elongation, accurate to , 1/10000 of an inch, were made by a special apparatus containing two micrometer screws, with electric contact attachment. The machine was operated by hand-power. Readings of elongation were taken at each increment of 2000 pounds stress per square inch, up to 44,000 pounds, the elongation corresponding to the latter figure being .0088 inch. The elongations up to this point remained almost exactly proportional to the stresses, the strain diagram, as shown on the Plate, from the origin to the point A, being a straight line (the deviation of no observation from the straight line being greater than .0002 inch). There being no indication of an approach to the elastic limit, the attendant at the hand-wheel and scale-beam was told to proceed as usual and move the poise forward 2000 pounds, or to 46,000, and turn the wheel until the beam was balanced. Noticing that the beam did not rise in the usual time, and that the elongation was increasing rapidly, the writer called to the attendant to stop turning the hand-wheel and to push the poise backwards until the scale-beam balanced. Instead of balancing at between 44,000 and 46,000 pounds, as was expected, it balanced at 40,000 pounds, and the elongation had increased to .0343 inch (or more than four times that recorded at 44,000 pounds), as plotted at the point B, the dotted line between A and B showing the supposed course of the strain diagram between these two points. Immediately upon recording the elongation the writer said to Mr. Gill, who was standing alongside: "This phenomena is without a parallel in my experience, and I know of but one way to account for it. The piece must actually be broken in its interior, through a flaw or weak portion of the metal. The test-piece is now equivalent to a tube, with

Jan 1, 1880

By S. F. Turcotte, B. J. Grierson

At the Q. I. T. ilmenite smelter, nine electric furnaces produce titania slag and iron At high power levels, a furnace requires either a slag or an iron tap approximately once an hour, using rail cars as slag receptacles and ladles for iron. The correct scheduling of taps is an important operational tool due to peak power load and operational considerations. Over recent years, large increases in furnace capacity have imposed severe strains on the product handling facilities. This situation results in loss of production when several taps are bunched, because of an in- ability to handle many taps simultaneously. An on-line computer program has been developed to generate schedules for tapping a single furnace. By improved scheduling, this program can en- large the tonnage of each tap and minimize the number of taps, while reducing traffic congestion and unit cost s. Future plans call for extension of this technique to all nine furnaces with addition of a master scheduling program to optimize the overall traffic flow in the smelter aisle.

Jan 1, 1969

By Harry V. Warren

There are two topics which may be considered as opening gambits in any conversation in any part of the world, weather and health. Nothing much can be done about the former, and it would appear that no great changes can be anticipated in the immediate future. With respect to health, a great deal has been achieved in the past 150 years, curiously enough not all of it by medical men. It would appear that the time is now appropriate for geologists to come to the assistance of medical men. During the past few decades, medical science has mastered many of the diseases commonly associated with childhood. As a man tends to live longer, those diseases usually associated with middle and old age become more prominent. Thus we must realize when we say that today more people are dying of cancer and coronary disease, absolutely and relatively to other diseases, this should not suggest that these diseases did not exist a hundred years ago; it does suggest that more people are living to an age where death from these diseases is apt to become more common.

Jan 7, 1962

By E. J. Hammer

Crushing and grinding of gypsum demands con- trolled processing to a fineness suitable for further treatment of the mineral into end products, and into various sizes of material which are themselves saleable products. The majority of gypsum tonnage ultimately ends up in stucco for wallboard. Therefore, mineral reduction is normally designed toward this end, but it is done in a manner that permits drawing off intermediate products to meet various customer requirements. This forces companies into compromises at times in equipment installations. Normally, 5 to 6 different sizes intermediate to the end product are marketed and these are generally the fineness of material to be used as stucco for wallboard. These sizes are produced by controlled crushing, grinding and sizing. How Ore Characteristics Guide Processing First, gypsum as a mineral (CaS0;2H,O) is number two on the Mohs scale two of hardness; only talc is softer, Despite being soft, gypsum is tough, a factor which is of critical importance when developing equipment specifications. In addition, of the increasing volumes of rock handled, the associated and included impurities such as anhydrite, silica or lime- stones are found to be relatively abrasive.

Jan 1, 1970

By G. S. Hume

In Alberta, an oil well with an estimated capacity of 60 to 100 bbl. was "brought in" at Wainwright, the oil being derived from the Colorado group of rocks. In the Norman fields, Mackenzie River area, two new holes completed showed no oil in commercial quantities whereas the "Discovery" well has now an increased flow amounting to about 100 bbl. In Kent Co., Ontario, a well from low down in the Trenton formation gave an initial flow estimated at 200 bbl. This opens up new possibilities for the Ontario fields as this is the first oil from this depth in the Trenton. ACTIVE drilling operations for oil were carried on during the summer of 1923 in various parts of western Canada, particularly in Alberta. During the early part of the summer, interest centered in southern Alberta, in the Coutts area, just north of the producing Kevin-Sunburst field of Montana; but on Nov. 14 a strike of oil by British Petroleums Ltd. at its well near Wainwright, 120 mi. east of Edmonton, diverted public attention to a new field. According to present estimates, this well has a possible production of from 60 to 100 bbl. a day; the oil is 15° Bé. with an asphaltic base and is obtained from a sand at the depth of 2019-2036 ft. The oil stands at 1700 ft. in the casing and there is sufficient gas pressure to cause it to flow when the well is opened. The oil horizon is in a sandstone in rocks of Colorado age. It is known that there is a terrace structure of which the western edge extends in a northwesterly direction from the vicinity of Hardisty to Viking, where it probably swings more to the north. At Viking a small dome-like structure on this terrace gives rise to an important gas field. Wainwright lies directly northeast of Hardisty. The exact structure in the Wainwright field is unknown. At Fabyan, 6 mi. northwest of Wainwright, the Imperial Oil Co.1 last year brought in a large gas well estimated at 14,000,000 cu. ft.; the escaping gas sprayed a small amount of heavy black oil over the derrick. The gas was obtained at a depth of

Jan 2, 1924

By John B. Pearse

IN order to get an idea as to the strength of steel rails, it will be well to review the tests to which iron rails have been subjected. In England, Mr. Ashcroft found that the best 80 pound rails broke under a 300 pound weight, falling 15 feet. In Germany the Society of Railway tyfanage1-s determined 011 and have long applied a test of 1000 pounds falling 101/2 feet, as the standard which all first-class iron rails must reach. In this country no inspection nor test is applied, but tests made show that iron rails fro; our most reliable makers, break under a G foot fall of a 1500 pound drop as an extreme test, most of those tested breaking under a far less test; some breaking with less than a 3 foot fall of the same weight. Everywhere where steel has been used, engineers have come to the conclusion that some test is required to show the regularity and strength of the product. As compared with iron, the tests which steel will stand are wonderful. After numerous experiments partially based on the experience of the rail-mill at Graz, belonging to the Southern Railway of Austria, the Society of German Railway Managers fixed upon a test of 2000 pounds falling 138 feet. They found that this test represented the steel which suited their necessities, and also found that with steel of otherwise average purity, this test represented about one-half per cent. of carbon, and made it a rule to take no steel containing under three-tenths of a per cent. of carbon, because it was too soft. They expressed a hope that a harder steel could soon be made tough enough to stand the same test. I n England, a test was adopted of 2240 pounds, falling 15 to 17 feet on the rail on heavy bearings. This test has been found satisfactory under heavy traffic on average road-beds, and has been invariably

By Stephen R. Holsinger

During 1972, Asarco's Silver Bell Unit embarked upon a project to test a digital computer-controlled grinding circuit against the performance of its other five grinding lines. The planning, implementation, and subsequent outcome of that project has been previously reported in a paper by Pittsl, et al. This paper will describe the solutions to major problems incurred during the implementation of this control strategy on the remaining five primary grinding lines. Changes made in operating philosophy and methods during the expansion will also be discussed.

Jan 1, 1979

PRESIDENTS DAVID THOMAS 1871 R W RAYMOND 1872-1874 A L HOLLEY1875 ABRAM S HEWITT 1876 T STERRY HUNT 1877 ECKLEY B COXE 1878 - 1879 WILLIAM P SHINN 1880 WILLIAM METCALF 1881 RICHARD P ROTHWELL 1882 ROBERY W HUNT 1883 JAMES C, BAYLES 1884-1885 ROBERT H RICHARDS 1886 THOMAS EGLESTON 1887 WILLIAM B POTTER 1888 RICHARD PEARCE 1889 ADAM S HEWITT 1890 JOHN BIRKINBINE 1891-1892 H M HOWE 1893 JOHN FRITZ 1894

Jan 1, 1923

By Fenton Scott, Patrick Hannon

Some occurrences of lead-zinc mineralization in Mississippian carbonates of central Nova Scotia are briefly described. The results of geophysical and geochemical prospecting are presented. Because the deposits do not give a positive response to these indirect techniques it is necessary to site exploratory drilling through the development of geological concepts.

Jan 1, 1976

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Junior and assistant engineers at $100 to $125 per month; assistant foremen and underground shift bosses at $150 per month; wanted for a large copper company in the West. Good opportunity for advancement. No. 77. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, graduate engineer, aged 44, with over 22 years' experience in connection with the development of large coal and coke properties in different parts of the country, desires position as general manager or general superintendent of large bituminous coal producer, or will take an interest and the management of a smaller operation. No. 258.

Jan 4, 1916

By C. E. Agnew

THE Eastern district, composed of New Jersey and eastern Pennsyl-vania, with its native ores, was the cradle of the iron industry of the United States. The district attained and held the leadership in produc-tion of pig iron for over 100 years, from pre-Revolutionary days to approximately 1875. The first shipment of Lake hematite ore was made in 1853. It was a small shipment, transported by a sailing vessel and a canal barge, but it was the beginning of the end of the supremacy of the Eastern district, although at that time the ore was supposed to be too rich to be successfully smelted with the block coal then in use at western furnaces. The iron made from the first shipment of Lake ore was worked into nails by the Sharon Iron Co., at Sharon, Pa. The writer's great-grandfather, David Agnew, and his brother, John P., Agnew, owners and-operators of the Sharpsville furnace, Sharpsville, Pa., worked the shipment through a furnace. Because of this, the writer feels some satisfaction in having been one of a group that solved the problem of making profitable an operation using Eastern district ores exclusively. With the development of Lake mines, and the production and use of coke, the Middle West district gradually assumed the position of leader-ship in production; because, even though the ores were transported 1000 miles by water and rail, its cost figure on pig iron was better than that of the eastern producer whose furnace was next to his mine. Such a cost figure was possible because the ore was naturally rich in iron and reduced easily. It was possible to carry a heavy burden on the furnace, which resulted in large tonnage and low coke per ton of iron. This paper is in no sense a technical one. The purpose is to show that with the proper physical preparation of the Eastern magnetites they will reduce as easily as the Lake hematites, and because of the high iron concentration give the Eastern producer just as much advantage as formally he was at a disadvantage in comparison with the Middle West producer.

Jan 1, 1938

By Ray W. Amstutz

The shaft was drilled on US government land m the Piceance Creek basin and was funded by the US Bureau of Mines (USBM). It was drilled to 723 m to provide access to rich deposits of oil shale, nahcolite, and dawsonite for geotechnical test work and environmental mining research. Rotary drilling and dual-string, reverse-air, jet-assist circulation methods were used. Drilling required eight months. Site preparation, running, and cementing the casing required another four months. A 2.44-m ID steel welded casing, 508 mm thick was installed and 2.7 kt of cement were slurried and pumped into the annulus.

Jan 1, 1982

By M. S. King

A series of cross-hole acoustic measurements have been performed in a columnar-jointed basaltic rock mass around an underground opening mined by the drill-and-blast method. The purposes of the test program were: to evaluate the rock mass characteristics around the opening; to determine the zone of blast damage; and to evaluate seismic methods for anomaly detection ahead of mining in this type of rock. The cross-hole measurements were made between four 76-mm diameter horizon- tal boreholes diamond-drilled 12 m into a wall of the underground opening. Repetitive pulses of compressional (P) and shear (S) waves of frequencies in the range 3 kHz-100 kHz were propagated from a transmitter sonde through the rock mass to a receiver sonde, both of which were clamped hydraulically to the borehole wall. After amplification the received P- and S-wave signals were digitized at the surface by a digital oscilloscope and stored on floppy discs. The results indicate considerable reductions in P- and S-wave velocities at distances less than 2 m from the face. Clearly these low values are associated with blast damage. Beyond 2 m, the velocities in a vertical direction indicate almost constant values. The velocities in the horizontal direction beyond 2 m appeared erratic, but showed a general tendency to increase as a function of distance from the face. Their maximum values remained, however, still lower in value than the corresponding velocities in the vertical direction. Near the face, the differences in velocities were considerably greater: with horizontal velocities considerably lower in value than those vertical. Results of the spectral analyses of the received signals indicated that Q-values were strongly influenced by the vertically- oriented sets of joints. Only for waves travelling in the vertical direction was the effect observed of the blast-damaged zone immediately around the opening. The acoustic data obtained are clearly indicative of an anisotropic jointed rock mass, with a greater intensity of jointing for travel paths in the horizontal than the vertical direction. The vertical, columnar joints are probably less tightly closed than those oriented in the horizontal plane.

Jan 1, 1984

By Byron E. Eldred

Generally speaking, the practical study of combustion has been made mainly from the stand-point of the steam engineer. This narrow view-point has left open a large field for scientific research on the application of combustion in other arts, where the conditions of heat-utilization are widely different from those presented in the steam-generator. The great economic importance of the boiler and the ease of measuring its performance, together with the comparative uniformity of conditions in the steam-generator, is, probably, quite largely responsible for the practical neglect of the study of the use of fuels in other arts save only on the basis of their thermal value. yet these other arts show quite plainly that a thermal-value basis alone is not sufficient. For example, in burning lime, under ordinary conditions of firing, a cord of wood will do as much work as a ton of coal, though the latter affords more than twice the number of heat-units. Similar results are evidenced in burning brick, in the roasting of certain ores, in reheating billets, and in many other, arts where heat is to be applied over extended areas to fragmental masses of more or less refractory materials. In these arts much is to be gained by a

Jan 1, 1911

By A. L. Holley

THOSE who are familiar with working gas furnaces will perhaps admit that the ordinary producer is the least satisfactory feature of the- whole system, chiefly by reason of its great waste of fuel, both above and below the fire. The waste of fuel in cleaning the fire has not, as far as I am aware, been carefully measured ; it has been roughly estimated at various works as averaging twenty per cent. to twenty-five per cent. The coke that falls into the ash-pit is largely mixed, if not stuck together with clinker; when this coke is not recovered and utilized (and where coal is cheap it does not pay to recover it), the waste is certainly as high as above estimated. Cleaning a fire on a grate (especially a fire of dirty coal, like much of our Western coal), by inserting a few temporary grate-bars, then withdrawing the regular grate-bars and letting the whole lower part of the fire tumble into the ash-pit, must necessarily be wasteful of fuel, but it has been found to be the most practical system. The fire under a boiler should be thin, to insure perfect combustion; hence it may be moved from one side to the other, so that .the clinker and ashes may be uncovered and removed. But a producer fire should be so thick that carbonic oxide only shall rise from it ; a thick fire cannot be thus manipulated. In several of the French works the ordinary producer without grates is employed ; the whole body of the fire rests on the floor of the ash-pit. It did not seem to me that less fuel was wasted here than with grates in cleaning fires. The bottom layer of the fire had to be drawn out with hooks, and there was nothing to prevent much coke from coming away with the clinker and ash. A producer shaped like a cupola furnace has many advantages, but if grates are employed the waste of coke in cleaning is not lessened. But the waste at the bottom of the fire is only a part of the waste in the ordinary producer. Mr. Emmerton, chemist to the Joliet Iron and Steel Company, has lately made a number of gas analyses from the producers of that company, worked with impure Illinois

Jan 1, 1880