Search Documents

By Pierre R. Hines

Diphenyl guanidine is used as an accelerator in vulcanizing rubber. Other rubber accelerators are also flotation collectors, e.g., dithiocarbamate, thiazole, and the xanthates. Urea and its derivatives are good flotation collectors,1 and guanidine is the nitrogen analog of urea. These two characteristics suggested testing diphenyl guanidine as a flotation collector. Diphenyl guanidine has been tried in flotation work previously, but references give no details.2-4

Jan 2, 1959

The four papers making up this symposum have been prepared especially for those who have no knowledge of seismograph prospecting. To many people mathematics is a formidable subject, and many are discouraged from studying seismograph prospecting under the mistaken assumption that the mathematical requirements are severe. In the papers presented here there is not a single mathematical equation. We believe that considerable competence in dealing with some of the most important problems of this work can be attained without any mathematical training whatever. At the present time, there is a real need for interpretation of results by persons thoroughly competent to bring geologic experience and imagination to bear on data that are subject to multiple interpretation from a strictly physical viewpoint. Likewise, those charged with the responsibility of planning seismograph exploration campaigns would do well to become familiar with as much as possible of the technical aspests of the work. They would then be in better position to judge of its success in individual cases. It has often been said that the seismograph is a new structure-finding tool for the geologists to use. Using a tool and using its product are two different things. One does not use an automatic screw-threading machine when he buys a box of screws at the hardware store. Neither does the geologist

Jan 1, 1940

The four papers making up this symposum have been prepared especially for those who have no knowledge of seismograph prospecting. To many people mathematics is a formidable subject, and many are discouraged from studying seismograph prospecting under the mistaken assumption that the mathematical requirements are severe. In the papers presented here there is not a single mathematical equation. We believe that considerable competence in dealing with some of the most important problems of this work can be attained without any mathematical training whatever. At the present time, there is a real need for interpretation of results by persons thoroughly competent to bring geologic experience and imagination to bear on data that are subject to multiple interpretation from a strictly physical viewpoint. Likewise, those charged with the responsibility of planning seismograph exploration campaigns would do well to become familiar with as much as possible of the technical aspests of the work. They would then be in better position to judge of its success in individual cases. It has often been said that the seismograph is a new structure-finding tool for the geologists to use. Using a tool and using its product are two different things. One does not use an automatic screw-threading machine when he buys a box of screws at the hardware store. Neither does the geologist

Jan 1, 1940

By D. H. Newland

On the bulk basis New York's contribution to the production of oil is small, representing, as it does, a bare half of one per cent of the annual total for the United States. Yet it has more importance than is implied by such a statement. Petroleum includes a variety of organic compounds, some more and some less valuable. It would be a fairer estimate of the situation to say that New York in recent years has produced around 10 to 12 per cent on the average of all Pennsylvania grade oil, the supply of which is strictly limited and the demand steady even in times of overproduction of other grades. One may not infer from this that New York and other Appalachian states enjoy an independent position in the market with a price structure uninfluenced by that of the Mid-Continent, Gulf or California fields. On the other hand, the recent market demoralization in the South and West brought about by uncontrolled production caused prices to drop to a point where the life of the local industry was seriously threatened. The current cost of producing oil in New York under the methods of water-flooding, by which most of the output is now obtained, has been estimated by competent authority at not less than $2.50 a barrel. The

Jan 1, 1934

By A. M. Gaudin

TEN years ago Taggart, Taylor and Ince1 described a workable, convenient apparatus for the measurement of contact angles be-tween cleaved, ground or polished particles and captive bubbles. Wark and Cox2 and Wark and Sutherland3 have done an im-mense amount of experimental work with this apparatus. Their work has had as principal object the determination of "con-tact curves." Contact curves are Cartesian charts in which pH (or some other variable) is plot-ted against quantity of modifying agent. The rectangular area is broken into two or more curvilinear areas separated by the contact curve. The curve indicates that a sharp demarcation exists between condi-tions that bring about sticking of particles to bubbles and conditions that do not pro-duce sticking, The type curve appears in the TRANSACTIONS as Fig. 1, page 248, volume 112. Wark and Cox offer data to show that the contact angle has a value determined by and characteristic of the agent used. Wark and Cox also make the statement that they believe this value is independent of concen-tration (ref. 2a, p. 209), They say: It is suspected that, given sufficient time and provided that there are no disturbing factors. the full ethyl xanthate angle (corresponding to a complete xanthate film) would be obtained in every case where contact occurs.

Jan 1, 1940

[ ] (14) SCREENS: Description of Allis-Chalmers' complete line of vibrating screens for the mining industry is contained in a new 8-page bulletin. Primary scalping, secondary scalping, and conventional screens for wet or dry sizing and screens for heavy media separation are included. Also given is a typical fiowsheet showing how horizontally operated Low-Head screens are used in the sink and float process. (15) MILLS: Forty-six years of experience and 4000 installations throughout the world lie behind the seven basic types of mills illustrated in a recent bulletin from the Hardinge Co. Fields of application and materials handled in various installations are listed. (16) BLOWERS & COMPRESSORS: A brochure describing the manufacturing facilities and the axial and centrifugal blowers and compressors made by the Sawyer Bailey Corp. is now available. (17) LINATEX: The first catalog of the Linatex Corp. of America has been issued, outlining the advantages claimed for this special form of natural rubber, when used in corrosion, abrasion, and vibration resisting applications. (18) WIRE ROPE: Twenty-four pages packed with concentrated wire rope data is the way E. H. Edwards Co. describes a booklet which they are now making available. It was condensed from the Edwards general catalog to provide users with a concise guide to every important phase of wire rope production, maintenance, and use.

Jan 1, 1952

By Thomas M. Plouf

Flotation, as we know it today, is a physiochemical method of concentrating finely ground ores. The process involves chemical treatment of an ore pulp to create conditions favorable for the attachment of certain mineral particles to air bubbles which are carried to the surface of the ore pulp for removal. Frother reagents, combined with air and the agitation mechanism, produce the effective bubbles in a flotation cell. A method of analysis is presented to evaluate the effect of frother reductions and additions on a bank of flotation cells, and to economically determine if and to what extent frother reductions and additions are justified. Comparative evaluations of different frother systems, as well as the amount of frother used in a given flotation machine, cannot be made on the frother cost alone. An indepth study must be made to evaluate any given frother as applied to a particular ore body. The recovery of a given mineral is as dependent on the amount of frother as on the type of frother used. An actual case study follows in which the amount of frother required by two different flotation machines was used to make a decision as to which unit performed more efficiently based on costs. This same method may be used to evaluate new frothers as well as to determine if a larger frother addition is advisable.

Jan 11, 1975

By Charles R. Fettke

The Bradford and Richburg oil fields are the only pools where artificially conducted water drives on an extensive scale have been economically successful. Field practice has progressed from the original accidental or intentional circle flood, through the line flood development plan, to the intensive complete development plan, which is the most-recent and generally considered to be the most successful. Of the intensive development plan the five-spot arrangement of wells is the one that has been used most extensively. A further development associated with the latter method is the application of additional hydraulic pressure to that of the hydrostatic head of the column of water in the intake well. In conjunction with this method is the practice of delayed drilling of the oil wells until the water from the intake wells has entered even the less permeable portions of the sand and developed a "bank" of oil at which time all oil wells are drilled as nearly simultaneously as possible. The five-spot pressurc flood with delayed drilling gives more rapid return on investment than any other method. The seven-spot and nine-spot patterns are rarely used. No chemicals, such as sodium carbonate and other so-called flooding agents, are being added to the water at present since the field tests carried on in 1926 gave no positive results. All air and gas drives have been discontinued.

Jan 1, 1930

By R. W. Heckel, J. H. Smith, H. W. Paxton

The habit plane of proeutectoid cementute precipitated from austenite was studied using a two-trace surface (analysis coupled with a direct X-ray back-reflection determination of the orientatzon of the parent Matrix. The results were the same as those obtained by earlier workers1 - 2 who used Indirect methods to determine the orientation of the matrix. The data indicate that a range or habit planes in the parent phase is operative which is not in agreement with accepted existing theories. In 1933, Mehl, Barrett. and smith1 obtained a non-unique result in a study of the Widmanstätten habit plane of proeutectoid cementite. Their data are shown in Fig. 1. These results were verified by Greninger and Troiano,2 although they did not pre-sent any data. Both of these investigations relied upon indirect methods of determination of the matrix lattice orientation. Theoretical considerations of Widmanstatten precipitates have usually proved or assumed an orientation relationship between matrix and precipitate; the habit plane expressed relative to the matrix is generally unique, although it may be irrational.3 Opinion is divided as to the factors influencing the choice of habit plane. Mehl4 felt that a nucleus which was plate shaped to minimize strain energy and surface energy during its formation could maintain this shape by the point effect of diffusion; the

Jan 1, 1961

By P. K. Guerrero, Nathaniel Arbiter

The correlation of power consumed by a tumbling mill with the dimensions, speed, and load has been attempted by three principal methods. One of these, the torque formula, has been reviewed critically elsewhere. This approach, while analytical, disregards the individual motion and speed of the tumbling bodies and assumes that the gross geometry of the entire load is sufficient to establish the power requirement. A more general approach, using dimensional analysis, has been applied in this laboratory by the present authors, and more recently by Rose. This disregards the internal conditions within the mill entirely and in effect is an empirical procedure for correlating data. Finally, the complete analysis of tumbling mill dynamics as first made by Davis attempts to develop the power requirement from individual ball and rod paths and velocities. Although Davis' result is applicable only at a single speed for a given size and load it could be useful, since his optimum speed is at the upper limits of conventional tumbling mill practice. Where power values predicted by the Davis equation were compared with actual mill requirements, they were found too low for small mills and much too high for the largest mills. This suggested that the agreement with actual intermediate range requirements might be fortuitous, and the development of the equation was examined critically.

Jan 5, 1960

By Theodore Nagel

Fuel-oil, natural gas and coke oven gas, producing the higher temperatures of open-hearth current practice, have been gradually displacing producer gas the lowest cost fuel for open hearth operations. The lower temperatures of combustion products from producer gas is caused by nitrogen dilution. Practical Application of Combustion Thermochemistry One pound of carbon burned to CO produces 3,960 B.T.U. and one pound of carbon burned to C02 produces 14,140 B.T.U. The second unit of oxygen uniting-with gasified car-bon (-CO) produces (14,140 - 3,960) 10,180 B.T.U. which is;(10,180 - 3,960) 6,220 B.T.U. more heat than produced by the first, unit of oxygen forming CO by uniting with solid carbon. A review of the relative combustion heating values of commercial gaseous fuels reveals CO requires a minimum of air for combustion, and because of minimum nitrogen dilution and the high thermal release from CO higher temperature combustion products are produced from CO than from natural gas or from coke-oven gas under similar combustion conditions. Inert nitrogen diluent lowers the calorific value of fuel gas and its diluting effect is cumulative in lowering the temperature of the products of total, combustion. It is not only logical but, practical in partial combustion, converting bituminous coal to gas, to generate the gas, with reduced nitrogen dilution.

Jan 1, 1936

THE Leadville tunnel, a Bureau of Mines project designed to unseal Colorado's rich but flooded lead, zinc, and manganese mines, is still being advanced, although the work is encountering severe difficulties. Work on the tunnel, begun in 1943, was dropped for lack of funds in 1945, and started again last September. The tunnel is one of the nation's toughest mining jobs. Fifty firms and individuals, who were asked to bid on the job of continuing be- yond the 6600-ft mark, didn't even answer. The work was finally taken over by the Utah Construction Co. of Salt Lake City. Since last September, the face has been moved 1000 ft closer to the flooded Leadville district mines, and to the hoped-for length of 17.300 ft. Some apparent success has already been noted, with an unusual decline in the water level in some major mine shafts reported this winter.

Jan 5, 1951

By L. D. Jaffe, H. C. Mann, E. L. Reed

It has been generally believed that fracture originates at a point and, if the stress is suficient, propagates across the material from this point. Evidence to the contrary is given in Fig 1. This micrograph shows an area close to the fracture of a steel containing The material had been quenched from 1675°F and tempered at 1150°F as a round about 10 in, in diam, and had a static tensile strength of 132,000 psi and a static yield strength of 105,000 psi. The steel was broken in 3000 cycles of reversed bending at a nominal max. fiber stress of 110,000 psi at a speed of 10,000 rpm. It was in the form of a standard R.R. Moore specimen with 45" V-notch, 0.015 in. radius and 0.220 in. diam at base of notch. The fractured edge in Fig 1 is part of the central portion of the specimen which broke during the final sudden fracture. Attention is directed to the short cracks which appear as dark lines within the specimen. Similar cracks were found in another specimen of the material, broken in 1,798,000 cycles at a nominal stress of 40,000 psi. The cracks were found in several areas close to the path of the final sudden fracture. This final fracture appeared microscopically to be wholly brittle and transcrystalline. Closer to the surface of the specimens, near the path of progressive fracture, which presumably advanced gradually during many cycles, there was microscopic evidence of some local deformation, but no microcracks. Neither were microcracks observed in areas distant from the main fracture path. The following explanation is offered: In the sudden fracture of the specimen, a crack propagates along a crystallo-graphic plane, with little or no plastic deformation of the adjacent material, until it reaches a grain boundary or a particle of carbide or inclusion which stops its advance. (The particle or boundary may be outside the plane of polish and not visible in the micrograph.) A stress concentration occurs about the end of the stopped crack. One or more new cracks are likely to start in the zone of this stress concentration. They may lie in the same grain as the first crack or in an adjacent grain. New cracks may occasionally start in a nearby but not adjacent grain whose orientation with respect to the stress leads to more ready fracture than does that of the grain between. Once started, these cracks propagate along crystallographic planes in their grains and the process repeats. This leads to discontinuous, branching chains of microcracks. As the process continues, microcracks probably tend to link up by fracture of intermediate material under the influence of increasing stress concentration. Occasionally, too, there may be a series of nearby grains of similar orientation so that there is a certain continuity of fracture across them. In either case the effective size of a crack is increased, resulting in greater stress concentration at its ends and a greater likelihood of further increase of size of the continuously-fractured region. When one continuous crack crosses the entire specimen, macroscopic fracture has occurred. The fractured edge of the specimen in Fig 1 represents a series of microcracks which became continuous across the entire specimen. The short, dark-appearing cracks in the figure did not become continuous over a large area. The row of microscopic stress concentrations at their ends may link up with those of the "main crack" outside the plane of polish. The above explanation does not imply that microcracks develop at the same rate in all portions of the specimen. They will develop most rapidly where the macroscopic tensile stress and macroscopic stress concentration are greatest. Viewed on a scale large compared to the grains, the fracture would appear to progress continuously across the specimen. Although Fig 1 shows a specimen broken in a fatigue test, it is believed that the microcracks discussed do not depend on the repetitive nature of the stressing used, since they are in the region where "sudden" fracture occurred, presumably in a single stress cycle. The whole process of microcrack propagation outlined above is thought to have occurred during this single cycle. It is believed that discontinuous crack propagation may be universal in brittle transgranular fracture of crystalline solids. Further experiments are under way.

Jan 1, 1950

By K. R. Crocker

PRIMARY blasting at the open pit of the Cananea Consolidated Copper Co. has been developed to meet several conditions peculiar to the operation. Mining at Cananea is not confined to the open pit but is in conjunction with the underground mine which has been in operation for many years. Several old stopes included in the pit area were filled with waste obtained in stripping for the pit. The main haulage tunnel for the underground ore passes directly under one section of the pit and at present is but 180 ft below the pit floor. The pit as originally laid out called for an overall final pit limit slope of 60°. However, the upper 275 ft - a fairly soft oxidized capping, was carried at a 50° slope and the lower benches, which constitute 750 ft in combined height, are being mined to an over-all final slope of 60°.

Jan 6, 1950

In mid-November, a long awaited announcement was made by John Drybrough, President of Granduc Mines Ltd. In short, he said that the extensive exploration conducted by his company and its parent organization, Newmont Mining Corp., have indicated the feasibility of a commercial copper mining operation at the company's prospect located slightly north of Stewart, B.C., and just east of the Alaskan Panhandle. The financing of the project is now being planned. SUMMARY OF PROJECT Granduc reasonably assured ore reserves are estimated at 32,510,000 tons averaging 1.93% copper content before dilution, of which 20,670,000 tons averaging 2.08;:; copper content are situated above the proposed mine access tunnel at elevation 2475 above sea level. The life of the reserves at the planned rate of production is 13 1/2 years. The probability of finding substantial additions to these present reserves is considered good.

Jan 12, 1963

Salt Lake City was founded July 24, 1847, by Mormons under the leadership of Brigham Young. It had a population of 1 18.1 10, according to the United States census of 1920, and of 15 1,968, according to a civic survey, January 1, 1925. The Salt Lake metropolitan district is estimated to have 180.079 inhabitants. The city's area is 5 1.8 square miles. Its altitude is 4,354 feet. It has 514 miles of streets, of which 91 miles are paved. The streets in the main portion of the city are 132 feet wide and the blocks are 660 feet long. It has 144 miles of street railway and 2,200 electric street lights. It has fifteen parks and playgrounds, forty public schools and six private schools. It has eighty-nine church edifices, of which forty-nine are devoted to denominations other than the Mormon church.

Jan 1, 1925

By M. J. Langley

Zinc ores were first discovered in Tennessee in 1856 at Jefferson City where a deposit became the Mossy Creek mine. From that time until 1913, small- scale attempts at prospecting and mining were made in various parts of the district. The actual systematic development of the zinc deposit dates from 1913 when the American Zinc Co. started operations at Mascot. Mining in the Mascot-Jefferson City area today is devoted exclusively to the zinc sulfide, sphalerite. Various grades of zinc mineralization have been found intermittently through a 600-ft vertical thickness. However, the commercial ore is confined to a total thickness of about 250 ft, from which it usually is mined irregularly from four or five separate levels known locally as "ore runs." In a few places vertical thicknesses up to 150 ft have been mined where commercial material extended from one run to another.

Jan 10, 1962

By Henry T. Mulryan

Since World War II, U. S. chemical companies have loosed a flood of synthetic organic insecticides. These synthetics fall into two broad categories. DDT is the best known of the chlorinated hydro- carbons and Parathion is the most famous (or infamous) of the organic phosphate nerve gas type. Insecticide poisons are not applied at full strength but as dilute sprays or dusts. This permits a broader and more efficient distribution of the active killer.

Jan 12, 1958

By W. L. Zeigler

THE tailing from the gravity concentration plant of the Hecla Mining Co., Gem, Idaho, was former-ly loaded into railroad cars to be used for ballast, highway surfacing material, or concrete work, or dis-posed of by an aerial tramway, which dumped it into another gulch. The tailing averages about 1.2 per cent lead and 0.8 oz. silver to the ton. Further treatment for the recovery of the valuable metals had been investigat-ed several times with results that did not warrant the construction of a retreatment plant; but early in 1925 experimental work was again started with small tests, and later with a 10 tons per day flotation test plant. This showed that the tailing could be ground and treat-ed by flotation at a profit. It was decided to make the new flotation plant an addition to, rather than incor-porate it in the old concentrator, the original capacity of which had been increased many times, the present arrangement being by no means ideal. The old mill buildings were of timber and board contruction, creat-ing more or less fire hazard, so all new construction was made fireproof. Construction work on the new plant was started in the middle of July, 1925, and the plant was placed in operation early in December. The building is of concrete and steel with hollow tile walls, steel sash and corrugated asbestos roofing. The ball-mill floor has for its foundation a cellular reinforced concrete block about 14 ft. deep, extending to cemented river gravel, and the cells filled with tailing to give weight to the block. Overhead, built into the steel frame, is a 5-ton hand-operated traveling crane. With both ball-mills running fully loaded, there is not the slightest trace of vibra-tion in the foundation or building. The flotation floor is of reinforced concrete beam construction and spans Canyon Creek. Adjustable plunger feeders are arranged under the the tailing-bin, which feed by gravity to a 14-in. eleva-tor, discharging to a short 18-in. conveyor. From the conveyor the tailing is discharged into a dividing hop-per, from which point the plant is arranged in three separate units. Each unit consists of a ball-mill in closed circuit with a classifier, and an 8-cell flotation machine and has an approximate capacity of 300 tons per 24 hours.

Jan 8, 1927

ZAY JEFFRIES,* Cleveland, Ohio (written discussion?).-The microscope has, indeed, proved a mighty tool in the study of the structures of substances. It is limited in its resolving power to the wave length of the light used for illumination. A little in resolving power can be gained by using ultraviolet rays, which can only be detected by the photographic plate. Even the highest powered microscope only permits the study of aggregates of millions of atoms. The x-ray spectrometer, on the other hand, makes it possible to study the positions of the atoms in a crystal. The positions of the atoms in over fifty crystals have now been ascertained. But in amorphous substances the x-ray spectrometer is only able to tell us that the atoms seem to have no regular arrangement; the actual arrangement and method of grouping is still a mystery. In most perfectly formed crystals and in so-called "grains" in metals, the x-ray spectrometer teaches us that colloids seem to play no role inasmuch as the atoms are arranged in regular layers rather than in random clusters. In the boundary region between crystalline grains of like as well as unlike substances and in amorphous substances like glass, it seems probable that the random clusters, or colloids, play an important role. There still remains the application of wave lengths connecting the ultraviolet and x-rays both by direct reflection or diffraction and by the ultramicroscope. In the study of substances like glass, for example, it may be possible to identify the clusters or molecules by one wave length and to study the positions of the atoms in a cluster by using a smaller wave length. Any light that can be thrown on this important unknown subject and its relation to the properties of substances is therefore very welcome, and Mr. Alexander's paper is so written as to stimulate thought and experimentation in this direction. JEROME ALEXANDER (author's reply to discussion ?).-Col. Bancroft states' that in the case of alloys, the mass is always crystalline. While this generally may be so in the case of alloys, as ordinarily met with, before the alloy reaches this state or condition, its constituent particles must be in a still more finely dispersed state. In alloys, the speed' of transition between the finely dispersed state where the phases are amorphous, and the crystalline state where the phases are of known composi-

Jan 5, 1919