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By Fleming, R. C.

ONE OF THE NEWEST developments of industry rising from the commercial application of scientific knowledge is in the making of solid carbon dioxide from the gas about 1925 the first efforts were made to manufacture "dry ice" on a large scale and at a price to permit widespread use. From that beginning the industry has grown to a consumption of 40,000 tons in 1930. Carbon-dioxide ice, as the name implies, is merely the gas compressed and cooled to a solid. The ice has a temperature of 109° F. below zero and is in many ways superior to water ice. It evaporates to a gaseous form so it is not wet and leaves no trace; in fact, one suggested minor use is as coasters under water glasses on the dining table. The gas is harmless except in large concentrations and. when the ice is used as a refrigerant, the resulting gas actually becomes a preservative, keeping oxygen away from perishable products. Not only does the ice have a greater amount of cold in a small volume than water ice but cooling is effected by direct contact of the resulting gas with the materials to be refrigerated rather than by convection air currents.

Jan 1, 1932

By Henry M. Howe

The death of Sir Lowthian Bell removes almost the last of the group of heroic leaders who made their age and ours the Age of Steel—a group which his luster and the luster of his peers, Bessemer, Siemens and Tunner, made one of the most brilliant, perhaps even the most brilliant, in the annals of induetry. Born on February 15th, 1816, in Newcastle-on-Tyne, he was the eldest son of Thomas Bell, an alderman of Newcastle, and of his wife Catherine Lowthian of Newbiggin, near Carlisle, in Cumberland, and was christened Isaac Lowthian, the name of his maternal grandfather. His father was born about 1788, and came in 1808 from Newbiggin to Newcastle, where he entered the office of the Cumbrian firm of Losh & Company, manufacturers of alkali and wrought-iron, at the Walker Iron and Alkali Works, at Walker, near Newcastle. Young Isaac Lowthian Bell was educated at Dr. Bruce's school in Newcastle, whence he went to Germany and Denmark, learning there German and Danish. On his return he studied at Edinburgh University, and then at the Sorbonne in Paris. As a student he already showed the remarkable character and application which later gained him such distinction. After studying the manufacture of alkali near Marseilles, he returned, and when about twenty years old (A.D. 1836) was employed in his father's firm, then called Losh, Wilson, & Bell. After spending a year in their Newcastle offices, and after visiting the important iron-making districts of France, Germany, Poland, and Austria, he took charge of their rolling-mills at. Walker, and profited so well by his opportunities, and especially by the teachings of his father and of Mr. John Vaughan (later one of the founders of the great firm of Bolckow, Vaughan & Co.), that he was made manager of the Walker works in or about

Jan 1, 1906

By R. E. Rowlands, I. M. Daniel

An experimental study is discussed of the state of strain, deformation and fracture around lined and unlined cylindrical cavities in rock under biaxial compressive static loading. The specimens were limestone plates 36 in. high, 24 in. wide and 3 in. thick with a 4 in. diameter hole unlined or lined with hydrostone and aluminum liners. The ratio of horizontal to vertical applied stress was one-third. Experimental techniques used were strain gages, differential transformers and photoelastic coatings. Strain distributions were plotted along the horizontal axis of symmetry for various levels of applied stress. The agreement with theory was good at low stress levels but appreciable deviations occurred at higher levels and near the hole. The experimental strain concentration factor was nearly the same, slightly higher and appreciably higher than the theoretical value for the hydrostone-lined, unlined and aluminum-lined specimens, respectively. Failure modes were splitting along a vertical plane for the unlined and hydrostone-fined specimens, compressive (shear) failure for one unlined specimen and splitting with radial cracking for the aluminum-lined specimen. In the latter, a maximum tensile stress of more than three times the uniaxial tensile strength existed at the interface with the liner at the time of fracture,

Jan 1, 1971

By Claudio Gutiérrez

The action of quebracho in the selective flotation of fluorite and calcite has been studied. It has been found that the unavoidable ions produced by dissolution of these minerals can precipitate calcium oleate which profoundly influences the adsorption of oleate. The depressing action of quebracho is due, at least partly, to a decrease of the oleate adsorption. The depression of flourite flotation by quebracho in the presence of calcium is due to the fact that precipitated calcium oleate can become only physisorbed, its adsorption being strongly prevented by quebracho. It is concluded that adsorption experiments with flourite must be conducted with a flotation-size mineral, which has a lower dissolution rate than when finely ground.

Jan 1, 1980

By S. C. Oliphant, R. Floyd Farris

Presented in this paper is a summary of the results of experiments conducted in both the laboratory and the field during the past three years in connection with casing-perfora. tion problems. Included are studies of gun features that influence bullet performance and penetration, and studies of the effect of perforator bullets on casing and the neat cement in the annulus. Discussion and data are also presented relative to the accuracy of depth measurements in deep wells. Introduction It is a common practice in the oil industry to effect the completion of oil wells by setting and cementing casing through the producing horizons and perforating the section of casing opposite the desired interval by means of a gun lowered into the well on a cable or on the tubing. This practice has been followed for some time, and this method of completion has been given considerable study by the companies that render perforating service as well as by the oil companies that utilize their services. Through continued research on this subject, it has been possible to develop guns, bullets, and powder that will permit controlled firing at great depths, and penetration of as many as two strings of casing. It is the object of this paper to present the results of studies made of gun perforating in both the field and the laboratory. These studies were made to determine the factors that affect penetration of the bullet, burring of the casing, accuracy of depth measurements, and other items. It is hoped that by presenting the results of these investigations a better understanding may be obtained of certain of the factors involved in gun perforating and further investigation of the subject will be prompted. Subsurface Tests A well approximately 9000 ft deep, which was being prepared for abandonment, was selected for subsurface tests of gun-perforating experiments, In preparing the well for the experiment, 51/2-in. casing in the hole was pulled and racked in the derrick. A test section of pipe, which consisted of 65 ft of 5-in. 18-lb J-55 casing centered inside 7-in. 28-lb N-80 casing, was placed in the derrick corner and the annulus between the two pipes was cemented from the bottom up with 161/2 lb per gal neat cement, which was mixed and displaced with a cementing truck in the usual manner. After the cement had been allowed to harden for about a week, the test section was lowered into the hole on the 51/2-in. casing to a depth of 6600 ft by casing measurements. The hole was filled with drilling fluid weighing 10 lb per gallon. A perforating company was called to perforate the pipe, but was not advised that an experiment was being conducted. The company was asked to check the total depth (to cross pins in the bottom of the test section), then to raise the gun a given distance and fire a given number of shots with 1/2-in. bullets, pick up another distance and fire a given number of 3/8-in

Jan 1, 1947

By John Henry Harden

With imperfect instruments it is impossible to make accurate surveys; the results are inaccurate maps, with their attendant consequences. The design of the writer is to describe an improved form of tripod head, and certain defects in an English transit and a miners' dial, with the method taken to remedy the defects of the transit. When the present transit superseded the surveyor's compass, there was one special objection brought against it, and with some show of reason ; namely, that the tripod of the compass with its ball and socket motion, allowed a quicker levelling-up (and, consequently, more work) than mas possible with the transit. To this objection it was replied, that the ball and socket would not allow the instrument to be levelled with the same degree of precision that could be attained with the levelling screws, and that if time was sacrificed greater accuracy was attained. Nevertheless, it is a wellknown fact that in this country, and especially in England, the compass or miners' dial holds its ground solely from its rapid adjustment. Ever since the introduction of the transit, efforts have been made to give to this instrument the same facility of levelling possessed by the compass or dial, and the same means have been tried, i. e., a ball and socket motion, since a modification of this in some form was the only method that would answer. The upper part of a transit is, however, much heavier than the corresponding parts of a compass, and, therefore, requires more binding power, which cannot be obtained with an ordinary ball and socket joint. It has been a study with instrument-makers to combine the facility of these two tripods —the quickness of the ball and socket with the steadiness and accuracy of the screws; but in all attempts in this direction the ball and socket of the compass has been literally followed, the entire stability of the instrument depending upon the friction of the ball in its socket. There is great need for a tripod that can be more easily manipulated than the present form, for it rarely happens that an engineer has a level surface on which to set his instrument, and very often

Jan 1, 1879

By G. Gutierrez, M. C. Fuerstenau, J. D. Miller

The response of pure goethite and two natural iron ores to flotation with potassium octyl hydroxamate is presented. The ores contained 12.5% and 39.7% iron; concentrates containing 69.5% and 61.5% iron, respectively, were obtained with additions of 0.4 lb/ton hydroxamate. Selective flotation of iron oxides from associated gangue minerals has proven difficult in the past with standard collectors, such as sulfonates and fatty acids. As a result, recent work has been directed toward silica flotation with calcium activation after the iron oxide surfaces have been blinded with certain starches.& The results obtained with this technique are encouraging. This method, however, involves depressing a mineral that would normally float under the conditions employed. A preferable method would involve floating the iron oxide because quartz is naturally depressed until activated. Earlier work involved this approach, but in view of the results obtained, collectors that exhibit greater specificity for iron are needed. During an investigation of chrysocolla flotation with potassium octyl hydroxamate, a metal chelate former, it was observed that pyrite floated well with low additions of collector.3 This phenomenon suggests that hydroxamate has a rather strong affinity for iron, and that other iron-bearing minerals should also respond to flotation with octyl hydroxamate. The object of this paper is to determine this response. The experimental work was divided into areas, the first of which involved microflotation experiments with pure goethite with an apparatus described previously.4 Goethite was selected because of the ease

Jan 1, 1968

By R. S. Silo

A new process for leaching oxidized copper ore (CuO) is presented. Its principle advantage is that it requires low cost raw materials. For large operations the only materials used are sodium chloride (NaCl) and calcium carbonate (CaCO3). In those operations of medium size, sulfur, which is abundant in the North of Chile, is used. However the process may also be applied to small copper plants provided low cost sulfuric acid is available as a substitute for sulfur. That is, it may be applied to those small capacity plants where large additional installations for the regeneration of the leaching solution are not needed. The method is comprised of six stages, namely: Crushing, Leaching, Washing of the Solution, Precipitation, Regeneration of the Leaching Solution, and Fusion. A flow diagram for this process in a large or medium-sized plant is given. LEACHING This process requires hydrochloric acid as the leaching solution for treating copper ores. This is easily produced from sulfuric acid and sodium chloride as follows: A small excess of NaCl is advisable to avoid the presence of free sulfuric acid. The experiments reported here were performed with 36 grams of HC1 per liter of solution to obtain a free acidity equivalent to 50 gpl of H2SO4 (the usual leaching solution concentration). Hydrochloric acid leaching may be done by either of the usual methods; i.e. percolation or agitation. The method selected depends on the characteristics of the ore. No matter which method is chosen, low pressure air can be used either as an air lift for circulation of the solution, or for agitation of the pulp with "Pachuca" tanks. In either case, there are no problems with respect to oxidation. Leaching by agitation produces good recovery; but at times, the problem of high consumption of leaching solution or the overproduction of grinding slimes which interfere with contact between phases negates this advantage. The percolation method was used in this study. Percolation took place in four 15-liter containers, 11 1/2 in. diam. by 12 in. height, having hemispheric bottoms. Each container was fitted with a wooden bottom having 1/4 in- holes. The air lift was a 3/4 in. plastic tube 10 in. high. Air at 6 psi was supplied from a rotating laboratory compressor. 10 kg of ore were charged to the container and counter-current leaching was used. The leaching solutions were fed through the center pipe in order to use the ascending solutions to reject the air in the charge. The solution circulated through the air lift in order to facilitate the movement according to the increase in density produced by the reaction between the phases present. Specific observations made in this report cannot be generalized because the leaching characteristics are dependent on the nature of the ore used, the method of leaching, and the production of primary or secondary slimes while crushing or leaching.

Jan 1, 1967

By C. R. Dale

The need for instruments to measure the movement of fluids and gas in wells has been recognized by engineers for many years. Information regarding flow in the producing interval has a direct bearing on completion practices in new wells and also provides information on the production characteristics of the well. Many hours of engineering time are spent in planning and completing wells but knowledge as to whether or not the original planning has produced the desired results has not always been complete. Many questions such as the following often arise: Why is it that two wells are completed under supposedly identical conditions, yet one well is a good one and the other is a poor one? Are the sands that look the best on the electric log contributing to the production? These and many other conditions in the producing well need to be under- stood in order to develop more efficient production practices and to improve on methods of completing new wells. It is the purpose of this paper to briefly describe one type of instrument, outline the methods of running the equipment and show the results of surveys made under various conditions. With an understanding of the use of this type of survey its importance can be evaluated in relation to the problems encountered by the operator. DESCRIPTION OF INSTRUMENT The instrument is a velocity recorder employing a clock-controlled 16mm film for recording the rpm of an extremely sensitive rotor which is rotated by the flow of fluids or gas in a well. The helical-vaned rotor and shaft, weighing one-half of one ounce are an integral unit exposed to the well fluids and are the only moving parts not enclosed in the fluid-tight housing. No packing or fluid seal of these parts is necessary and the shaft is mounted top and bottom on special jeweled bearings. Fig. A is the lower part of the instrument showing rotor and shaft with the protecting housing sleeve removed. The rpm of the rotor is recorded on the moving film by a combination electrical and optical system. The record is a series of dashes on the film, each dash and space representing twenty (20) revolutions of the rotor. (Film record of survey made in California well showing station recordings at various depths.) As the movement of the film is controlled by the clock the number of dashes and spaces in one minute of film travel represents the rpm of the rotor. The range of the instrument is from 0 to 2,500 rprn. The barrel or housing is 1-11/16 in. OD and seven feet long. Various types of expanding fluid traps are attached to the lower end of the instrument to direct the flow through the 1 in. orifice containing the rotor. The fluid trap for upward flow is shown in Figs. B and C. This assembly consists of eight arms with light spring

Jan 1, 1949

By C. M. Wayman, R. Bullough

The rediffraction of Bragg diffracted beams by differently oriented regions (such as twins) of a crystal may give rise to "extra" reflections or reciprocal lattice points. These two papers are concerned with predicting these additional reflections which result from twin related regions of a lattice. Analysis is made for {111}fcc twins, (112)bcc twins, and {hkil}hcp twins. It is first required, knowing the specific variant of the twinning plane in each case, to predict the positions of the twin reflections relative to the matrix reciprocal lattice. Once this is done, the positions of the "extra" multiply diffracted reflections may be deduced. Part I is devoted to establishing "selection ru1es" for twinning, i.e., the necessary and sufficient conditions for the existence of twinned reciprocal lattice points. 1. INTRODUCTION. Transmission electron diffraction patterns are frequently complicated by multiply diffracted beams. Pashley and stowell1 have recently demonstrated that certain extra reflections in evapo- rated films of gold result from the rediffraction of matrix Bragg diffracted beams by (111) microtwins in the gold. It was previously (and erroneously) suggested 2,3 that observed "irrational" reflections in fine-grained gold were due to the presence of some hcp gold. A similar situation exists, apparently, for some bcc materials; fine (112) twins in bcc martensite in Fe-Ni alloys4 give rise to extra reflections. There are many other examples. The number of transmission electron microscopic investigations is continually increasing, and because of the importance of double (and multiple) diffraction in the interpretation of diffraction patterns, it was judged that a detailed elaboration of the principles involved is desirable, as well as the extension of these principles in reasonably closed form to other crystal structures, particularly bcc and hcp. The present analysis considers double diffraction caused by (111) twins in fcc metals, (112) twins in bcc metals, and {hkil} = {hkl) twins in hcp metals. For each case of twinning, the various possible (variants of) twins give rise to a set of interpenetrating reciprocal lattices. The relative spatial arrangements of these reciprocal lattices can be deduced (Part I) and are expressed in terms of simple "selection rules". The resulting sets of interpenetrating reciprocal lattices are then analyzed for possible doubly diffracted reflections (Part II). The notation used, and some important formulas are given in Appendices I and 11.

Jan 1, 1967

By C. R. Tinsley

A strictly limited number of specialist project finance banks exists, with the necessary specialist personnel able to address project cost-competitiveness, cost and commodity forecasting, joint venture negotiations, and completion and sales undertakings. Different techniques of internal bank appraisal are applied, with the usual equity investment project valuation criteria being seldom useful for loan assessment purposes. Company attention paid to the preparation of a sensitivity structured bankable presentation can prove most effective for securing development project finance. Substantial scope is possible for savings of time and money.

Jan 1, 1985

Jan 1, 1945

By D. Harrington

WHEN the word gas is mentioned in connection with mining, almost invariably it is inferred that the explosive gas, methane, is in mind and that it must refer to coal mining. While it is true that methane occurs, or is likely to occur, in almost any or all coal mines, it is also a fact that the metal mines of the world have in them by far a greater variety of gases than have the coal mines. In many cases the gases in metal mines are as dangerous to individuals as the gases likely to be found in coal mines; in some instances the metal mine gases are even more deadly. The coal mine is more likely to have methane than the metal mine, in rare instances it may have high percentages of nitrogen or high carbon dioxide, or there may be a deficiency of oxygen where the air is confined in a blind end or in a sealed region; much more rarely there are found in coal mines in relatively small percentages, ethane, or other hydrocarbons with odor of ether, gasoline or kerosene, or there may be minute percentages of hydrogen sulfide. In time of coal mine fire or explosion, there is likely to be high carbon monoxide (4 per cent. or over in some cases) and if the coal contains much sulfur, there may be some sulfur dioxide in the fire fumes. In metal mines there are a number of cases of occurrence of methane and attendant explosions; some metal mines have appreciable percentages of the decidedly explosive hydrogen; in some metal-mining regions carbon dioxide flows into the mine, fills the workings and overflows just like water. In other regions, at many working faces there are high-temperature gases containing a mixture of gases of sulfur (sulfur dioxide, hydrogen sulfide and possibly SO3 in some cases) together with carbon dioxide and nitrogen, and the deadly hydrogen sulfide in lethal proportions is found in some high-sulfide metal mines at blasting time. Carbon monoxide constitutes a decidedly dangerous day by day hazard in connection with metal-mine blasting, because of the heavy charges of dynamite that are used and the use of fuse, which in burning gives off much carbon monoxide. The poisonous gas hazard is accentuated because of the relatively small openings where metal-mine blasting is done and to the inefficient ventilation of the usual metal mine.

Jan 1, 1930

By R. I. Jaffee, H. R. Ogden, D. J. Maykuth, W. L. Finlay

Titanium with up to 7.5 pct Al forms single-phase a alloys that are work hardening, not heat treatable, and ductile as welded. The high aluminum Y phase alloys are not usefully ductile, despite their low hardness, but they have excellent oxidation resistance and hot hardness. LITTLE has been published on the effect of aluminum on the mechanical properties of titanium, despite the fact that two of the first four commercial alloys released by titanium alloy producers contained aluminum as an important alloying ingredient. These were both a-ß type alloys, one containing 4 pct A1 and 4 pct Mn and the other containing 3 pct A1 and 5 pct Cr. However, neither of these alloys reflects the true alloying nature of aluminum, since each contains important amounts of the ß-stabilizing addition, manganese or chromium. In a previous publication on the constitution of Ti-A1 alloys,' the authors showed that aluminum had a high solubility in a titanium and was strongly a stabilizing in nature. About 25 wt pct A1 is soluble in a titanium at room temperature. With as little as 5 pct added aluminum, the a transus temperature is increased from 882" to 970°C, and the correspond- ing ß transus to 995°C. The first intermediate phase in the Ti-A1 system is the ordered face-centered tetragonal TiAl phase, which extends from 34 to 46 wt pct Al. The present paper presents hardness data over the entire titanium-rich region of the system, through the TiAl phase, and mechanical property data on the alloy range capable of being fabricated. Methods of Investigation The materials used and general preparation of alloys, as well as experimental techniques used in the investigation of Ti-A1 alloys, have been adequately described.' Briefly, the preparation consisted of arc-melting the desired amount of high purity aluminum (99.99 pct purity) and iodide titanium (maximum hardness 100 Vickers, as deposited) together on a water-cooled copper hearth under a partial pressure of argon. The resulting button ingot was of such form that it could be fabricated without further treatment. All work was done using ingots weighing 10 to 15 g, which were hot-rolled to strip form whenever possible. Tensile samples were 3.25 in. long, 0.5 in. wide, and 0.040 in. thick, with a reduced section 1.25 in. long by 0.250 in. wide. The gage length used was 1 in. Electrical strain gages mounted on the

Jan 1, 1954

By William P. Blake

The mineral, garnet, is a common associate of copper-ore in the southwestern portion of the United States. This association may be observed on a large scale in southwestern Arizona, in southern New Mexico and in Sonora, Old Mexico, especially at El Cananea, and at Nacozari. At other localities in Mexico the general occurrence of garnet " as a contact metamorphic mineral" in the copper-deposits of the Cretaceous limestone is noted by José G. Aguilera.1 It is usually found at the contact of this limestone with diorites, granites, etc., at numerous mines. The same authority also cites the occurrence of garnet in metamorphosed Cretaceous limestone alongside of diorite dikes in association with iron-ore. Other foreign examples are found in the Banat and Servia, at Rezbanya in Hungary, and Offenbanya in Transylvania, and at Bogoslovsk in the Urals. In New South Wales, at Broken Hill, the gangue in the Proprietary mine is chiefly garnet, with quartz, opal and rhodonite.2 Also, in a recent paper by George Smith, entitled, " The Garnet-Formations of the Chillagoe Copper-Field, North Queensland, Australia,"3 it is shown that in the copper-field of Chillagoe, Australia, where there are many lode-formations, about one-half of the number are garnetiferous, and many of this garnet-type are associated with magnetite, which is regarded as of analogous origin. The two minerals are found merging imperceptibly into each other. These examples suffice to show the very general and wide distribution of garnet as an associate of copper-ore. In addition to the localities already mentioned as known in Arizona may be mentioned the copper-mines and occurrences

Jan 1, 1904

By D. J. Carney, J. Chipman, N. J. Grant

G. Derge—With the development of this last weapon, there is not much of a chance for hydrogen. It is certainly a very interesting paper, and it gives us more confidence in sampling liquid steel for hydrogen than we have ever had before. This satisfactory work gives considerable confidence to all of the chilled methods of sampling which should be more or less successful depending upon the degree of chilling obtained. J. T. MacKenzie—How do you handle a nonmagnetic specimen in that device? D. J. Carney (authors' reply)—I left that out in going over the analytical procedure. For the 18-8 steel, what was done was to get some iron wire which was degassed. One turn of wire was made around the sample; it was inserted into the analytical apparatus, and that was enough to allow the magnet to pull the sample and drop it in the furnace. Other methods could be devised for this apparatus to do the same thing. This was just a quick method. C. E. Sims—This method of sampling and analysis is very ingenious, and the results obtained attest to a satisfactory degree of accuracy. It was noted in the paper that the samples are satisfactory only when there is a complete absence of pipe. This should be empha- sized, particularly in view of the fact that they are cut off under water. Some reservations are held in regard to the adequacy of the method of sample storage prior to analysis. Cooling on dry ice undoubtedly slows down the rate of diffusion to a marked degree, and it obviously suffices when the analysis is made within a few hours. All of the samples, except some of high-nickel steels, were analyzed within 12 hr. It is still unknown how long this method would be safe. In the work at Battelle Institute, it was impracticable always to start analysis within 12 hr for various reasons. Some samples did not reach the laboratory for several days, and some were held as long as a month before analysis. During this period, they were held over mercury, and the gas evolved at room temperature was collected and analyzed. It should be mentioned that both the mercury and the container must be kept very clean.

Jan 1, 1951

By Elbert Rowland

THE widespread interest in the alloys of beryllium with copper is due principally to the fact that certain compositions show very favorable precipitation-hardening characteristics and are, in fact, the strongest nonferrous alloys known at the present time. Investigations have been conducted by Masing and Dahl and others on the physical characteristics of ternary beryllium alloys, in an attempt to produce precipitation-hardening effects with a smaller amount of beryllium than that required in the binary copper-beryllium alloys (2.0 to 2.5 per cent Be). The results of these investigations show that ternary alloys of beryllium with Cu-Sn, Cu-Al and Cu-Zn, among others, exhibit promising improvements in physical properties after precipitation-hardening treatment and, while the increases in properties obtained are not as high as those realized from the binary copper-beryllium alloys, excellent properties are obtained with beryllium contents averaging about one-half the amount required in the binary alloys. This paper presents the results of an investigation of the equilibrium relations of certain alloys containing copper, tin and beryllium. The alpha-phase boundary of the ternary system is given for alloys containing from 0 to 1 per cent beryllium. The equilibrium conditions beyond the alpha-phase boundary are presented for alloys containing up to 32 per cent tin and 1 per cent beryllium. The data were collected by means of

Jan 1, 1935

By C. A. Mitke

During September, 1911, the fire area in the Lowell mine continually increased and gases resulting from the fire came through the upcast shaft. These gases contained such a large percentage of sulphur dioxide that the men were unable to go up and down on cages, and, within a comparatively short time, repairs in the shaft mere found to be necessary. Since the fire was in sulphide ores and extended into certain timbered sections, the gases contained varying amounts of SO2, CO2, and perhaps, at times, CO. The temperature in the shaft was generally about 97", and the relative humidity from 97 to 99.5 per cent. The corrosive action of the fumes became apparent when the cables had to be changed more often than usual, the heads of lag screws in the guides of the shaft disappeared, and the cages needed frequent repairs. It also became necessary to repair two compartments of the shaft by putting in 150 ft. of new guides between the 600 and 800 levels and lag screws in nearly all the old guides from the surface to the 800 level. 2. Ordinary Methods of Testing Helmets which were Unsatisfactory. These conditions required all work to be done by men wearing oxygen helmets. The Draeger type was tried, and was used until all repairs were completed. At first the helmets were tested for air circulation and air tightness and the injector mas tested by water gauge according to the methods recommended by the Draeger Oxygen Apparatus Co. Six arrangements, covering these different tests, are illustrated in the catalogue and circulars of the company. After the above tests had been made on the oxygen apparatus, the men still complained about leaky helmets. Small quantities of gas entered the helmets and could not be detected by these methods. The

Jan 1, 1914

By S. H. Ash

More than 100 minerals are mined and processed in the U. S. Management and labor have negotiated wage-scale agreements that have balanced wages and affected cost of labor in such a manner that comparisons can be made of transportation costs. Transportation of materials underground has become of vital importance. This report describes underground haulage methods and equipment, presents cost analyses, and discusses future plans for underground transportation in metal mines. It does not cover hoisting in shafts or slopes by cage, skip, or cars. Advancements have been made by the metal mining industry in lowering transportation costs in several mines, making it possible to mine orebodies or portions of orebodies not considered economically recoverable a few years ago. Numerous reports have been written on transportation at metal mines; this report covers recent haulage at some representative mines throughout the U.S. The term metal mine is used to include all noncoal mines from which up-to-date information was obtainable.

Sep 1, 1956

By G. F. Comstock

A serious disagreement as to the effect of titanium on the hardenability of steel exists in published references to this subject. Kramer, Hafner and Toleman reported' that acid-soluble titanium decreased creased the hardenability, with multiplying factors less than unity according to [ ] Grossmann's system for calculating hardenability from the composition. Crafts and Lamont, on the other hand, showed2 how titanium increased the hardenability, with multiplying factors up to nearly 1.7 for about o.' per cent titanium, though reducing the hardenability with higher titanium. Their data, however, were obtained almost exclusively from steels containing more than 2.4 per cent manganese, and thus should be considered as applying mainly to manganese steels. Likewise, the results of Kramer, Hafner and, Toleman regarding titanium are subject to the limitation that although they eliminated the effect of the insoluble titanium compounds from their calculations, they did not make a similar correction for the carbon that was combined with titanium and therefore occurred in a similarly ineffective form. It is suggested by the literature referred to that titanium may have different effects on hardenability, depending on the mode of its occurrence in the steel. The different effects on strength, ductility, etc., have already been discussed by the author.3 In the present discussion some comparisons, on the basis of hardenability as revealed by the Jominy end-quench test, are given between three titanium and two non titanium steels heat-treated in the same ways, and between other titanium steels heat-treated in several different ways. COMPARISON OF PLAIN-CARBON, VANADIUM AND TITANIUM STEELS The five steels used for these experiments were commercially melted and rolled products received in the form of 1.5-in. rounds from three different mills. Their analyses are given in Table I. Steels 2, 3, and 4 are from the same basic electric heat, containing 0.009 per cent of phosphorus and the same amount of sulphur. They were made by, adding aluminum and low-carbon ferrotitanium to different ingots. No. I is a plain-carbon coarse-grained S.A.E. 1040 steel made by the basic open-hearth -process. No. 5

Jan 1, 1945