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By M. C. Fuerstenau, W. F. Cummins

The flotation response of quartz in the presence of calcium chloride and various fatty acids is presented. Flotation is not effected with lauric acid until calcium laurate is precipitated in solution, while flotation is obtained with the 9, 10, and 11-carbon members before precipitation of the calcium carboxylate. The active species responsible for flotation is suggested to be a basic aqueous complex, e.g. Ca(OH) (RCOO) (aq), and a possible mechanism of adsorption is given. Most of the previous work on activation in non-metallic flotation systems has involved the use of high molecular weight collectors, such as oleic acid or alkyl aryl Sulfonate.1-7 In these studies the levels of addition of collector and activator required for flotation were much above the concentrations necessary for precipitation of the metal-collector salt. In fact, Clemmer, Clemmons, Rampacek, Williams, and Stacy1 have stated, "Our experiments on a variety of materials have demonstrated that the metal salts which react with anionic collecting agents, as soaps and alkyl sulfates, to form relatively insoluble compounds may be employed as activating agents provided an optimum quantity is used at a proper pH." On the other hand, Gaudin and chang8 obtained flotation with additions of barium and lauric acid below the level required for barium lautate precipitation.

Jan 1, 1968

By A. B. Fly

Borehole mining combines the principles of hydraulic mining, slurry mucking and rotary drilling. The borehole is drilled with conventional equipment and is cased down to the top of the mining zone. The borehole mining tool is comprised of the kelly-swivel assembly, multiple drill-pipe sections, and the jet-pump barrel assembly as shown in Fig. 1. The kelly swivel is fitted with a bail to support the mining tool. The kelly drive bushing engages the rotary table to allow the rotation of the mining tool while it is being operated. The jet-pump barrel assembly is comprised of the sidewall jet nozzles, the jet-pump assembly, the suction screen, and the tricone rock bit. Clean fluid is pumped at high pressure through the kelly hose to the high-pressure swivel on the mining tool. The high-pressure pipe conducts the fluid down to the sidewall jet nozzles, the pump jet nozzle, and the tricone rock bit. The sidewall jet streams cut the formation and wash the cuttings down to the rock bit. High-pressure fluid issues from the water courses to clean the bit and to agitate the cuttings. Rotation of the mining tool causes the rock bit to grind any oversize material enough to permit its passage through the suction screen. High- pressure fluid issues from the pump jet nozzle to provide the lift needed to pump the slurry to the surface. The slurry is discharged into the settling pits where the cuttings are deposited and the clean fluid is returned to the suction of the high-pressure pump.

Jan 3, 1969

By C. R. Garr, A. R. Troiano

FLAKING or hair-line crack formation has been a major problem confronting the producer of large alloy steel forgings.' Today it is generally conceded that hydrogen in one or more forms in alloy steel sections is a requisite for flaking. Hence an obvious remedy is a thermal cycle that reduces the hydrogen content to some low level. In practice, this generally means holding the material at some subcritical temperature for a period of time depending on the size of the ingot or forging. Another method that will suffice in some cases is to cool large forgings slowly, i.e., bury in ashes. In practice, this hydrogen bake is sometimes accemplished inadvertently by a series

Jan 1, 1958

By J. D. Meakin

The self-diffusion coefficients of ß tin have been deterttlltled using a plating and sectioning technique. The principal diffusivities pavallel and perpendicu1ar to the "c" axis are given by the Arrhenius relations Dc = 8.2 exp (-25,600/RT) sq cnl per sec and Da = 1.4 exp (-23,300/RT) sq cm) per sec. The results are discussed in terms of a vacancy mecharism of diffusion. In conjunction with an investigation of diffusion in dilute indium-tin alloys we have reexamined self-diffusion in tin single crystals. The published self-diffusion coefficients of tin, eensham') have always appeared anomalous in comparison to diffusion data for other metals and do not correlate with parameters derived from creep tests.' In addition to the necessity of confirming the self-diffusion values for use in analyzing the alloy work, self-diffusion in an anisotropic lattice is of considerable fundamental interest and confirmation of the published data seemed worthwhile. For a crystal with an axis of symmetry three-fold or higher the diffusivity at an angle 6 to the axis is given by D? = (Da - Do) sin2?+ Do [1] where Da and Do are the principal diffusivities perpendicular and parallel to the axis. For a particular diffusion mechanism, again in a crystal of axial symmetry, these principal diffusivities are [2] Do - ? ?i2 COS?i In these expressions ?i is the displacement undergone by the ith atom and 8, is the angle this displacement makes with the symmetry axis. In this, as

Jan 1, 1961

By William Glenn

The Ritchie vein, of Ritchie county, W. Va.,* was a straight fissure, about 3600 feet in length, which cut vertically downward across the horizontal beds of shale and of sandstone to a depth not ascertained. It might be described as lying in a. Vertical plane, bearing 12 degrees north of west. The geological horizon is that of the " upper barren coal measures'" of the Appalachian coal-field, being a part of the strata lying above the Pittsburgh bed. The vein matter was declared by Prof.

Jan 1, 1896

By E. E. Russell Tratman

The use of dynamite in cold weather is attended with some difficulty, owing to the freezing of the material and its consequeut liability to fail to explode when the fuse is fired. With proper methods and care the dynamite can be thawed with reasonable safety, but numerous accidents occur (more than get reported in the public press), due to carelessness in the operation and to the treacherous nature of the material, or a combination of both conditions. Dynamite will stand treatment at one time which at another time will result in explosion. An expert on explosives says that the most dangerous means of thawing cartridges are ingeniously devised by ignorant laborers; baking, boiling and toasting being favorite methods, while at a stone-quarry, in one instance, an apparatus was arranged for steaming the cartridges over a pot of boiling water. In this latter case the nitro-glycerine leaked through the canvas cover and settled on the bottom of the pot, with the result that an explosion occurred, the water acting as a tamping to the charge. The fact that small quantities of explosives containing nitroglycerine will burn quietly and without explosion if ignited by direct contact with a flame, has led to the dangerously mistaken reasoning that merely heating the explosive can produce no ill effect. If . a dynamite cartridge is ignited or placed in a fire it will probably burn harmlessly away, but if placed on a stove or in an oven and

Jan 1, 1893

By W. M. Pierce

CORRUGATED sheet zinc has been used abroad for a great many years as a roofing material. In this country it has been in use for about 10 years. From the outset it was recognized that zinc sheets required closer spacing of the supporting purlins than steel sheets. Exact data regarding safe maximum fiber stresses were not available, however, and on occasions the span used was excessive and the sheets sagged. This paper describes both service and laboratory tests to determine safe maximum fiber-stress values for various grades of zinc for use in calculating the proper purlin spacings for any gage and profile under given loading conditions. These tests consist of laboratory loading tests on full-size roof sections over extended periods of time; of actual roof installations erected in conformity with the indications of the laboratory tests and observed over a period of years; of careful determinations of the apparent elastic limit of several grades of zinc, and finally of static tests1 (so-called creep tests) to determine the rate of flow of zinc under a variety of static tensile stresses at definite temperatures. Certain of the individual tests extended over a period of more than two years.

Jan 1, 1929

By Thomas MacFarlane

DURING the last fifteen years the progress made in the science of lithology has been of a very marked character. From being a miscellaneous collection of facts and observations regarding certain mineral aggregates seemingly incapable of systematic arrangement, it has become a most interesting and orderly department of science. The investigators who have brought about this great change have recorded the results of their labors, and placed at our service an extensive and varied literature on the subject. To this I have paid some attention, and partly from .studying it, partly from my own observations, I have wrought out a classification of original or crystalline rocks, which I venture to bring under the notice of the members of this Institute. The practical importance of the subject will be acknowledged when it is considered that rock species are not without their influence on the contents of the mineral veins which intersect them. Besides, the Institute has been doing good service in defining terms in metallurgy, and no doubt in mining and geology we might

Jan 1, 1880

By D. W. Brunton

The object of the investigations and experiments here recorded was to obtain such information and data as would make it possible to determine the fineness to which crushing must be carried, in sampling gold- and silver-ores, in order to obtain results within an allowable limit of error.

Jan 1, 1896

By Wolfgang Pietsch

Pressure agglomeration using tableting machines, roll presses, punch presses, isostatic pressing equipment, extrusion presses, and other less common equipment, represents a large share among commercial applications of size enlargement by agglomeration. The paper attempts to classify and describe the equipment and technology, their development and state of the art, as well as their respective applications, advantages, and disadvantages.

Jan 1, 1977

By Henry G. Petrow, Edward S. Porter

MAJOR occurrences of lignite with significant uranium concentrations have been reported in western parts of the Dakotas, especially in Harding County, S.D., and Billings and Slope counties, N.D. Samples containing as much as 2 pct U3O8 were received at the Winchester Laboratory, but those deposits reportedly of major significance have generally contained 2 to 4 lb of uranium per ton of lignite. Most of the uranium appears to be associated with the carbon in the lignite as a urano-organic complex, although in most instances analysis of inorganic material has shown uranium values. Molybdenum is similarly associated with the carbon, and its concentrations generally parallel the uranium. The noncarboniferous material is mainly composed of gypsum, jarosite, bentonite, sandstone, and miscellaneous carbonates and silicates. The heating value of these lignites has been determined as about 3500 Btu on a dry lignite basis. The ash content of lignite has varied widely, the important samples containing 30 to 60 pct ash on a dry lignite basis. Because of the significant upgrading of uranium values obtained by ashing the lignite, and because recovery of uranium from raw lignite presented formidable processing problems, major emphasis at Winchester has been placed on devising methods to recover uranium from lignite calcines. Proper roasting removes the problem of organic fouling of solutions, reduces the size of the leaching plant for an equivalent uranium throughout, and generally provides equal or better acid leaching efficiency with less acid than can be obtained from the raw lignite.

Jan 9, 1957

By I. L. Box

IN planning retreatment of tailings, the material to be retreated should be thoroughly investigated, tak- ing into consideration the total tonnage, the blende content, the specific gravity of the different particles, and the grinding necessary to liberate the mineral. The tailing pile is surveyed by making a closed trav-erse around the outer edges, locating the stations at points from which a considerable portion of the pile is visible. From each of these points the pile is sur-veyed by stadia and a contour map made. The yardage is then calculated from the contour interval and the area inclosed by the contours obtained with a planim-eter. A party of three men can survey an average tailing pile in one and one-half, days. In calculating tonnage it is assumed that 22 cu. ft. of tailing in place equal one ton. Sampling is done by the use of an auger with casing to prevent the hole from caving. These holes may be bored 12 to 15 ft. deep by hand, but to penetrate the entire pile some kind of power is applied to drive the casing and raise or lower the auger. The latter method is more expensive but the increased cost is more than compensated for by the value of the information obtained.

Jan 7, 1928

By Robert Davis Longyear

In diamond-drill work, a true sample consists of all the material cut by the bit—both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little value if an inaccurate sample is obtained. The engineer in charge must study his material and lay out the plan of sampling, and then see that the drill runner follows his instructions; for the runner may be more interested in obtaining a large footage than in developing accurate methods of sampling. When the core has been removed from the core barrel, it should be placed in a core box in the exact order in which it is taken from the ground. This box, Fig. 1, is usually a shallow tray 4 or 5 ft. (1.2 or 1.5 m.) long, with partitions running lengthwise between which the core

Jan 1, 1923

By J. J. Bean

Concentrating mixed sulfide-oxide copper ores by the leach-precipitation-flotation method is an old operation at the Miami Copper Co. The idea was conceived and the method developed at Miami by F. W. Maclennan and Harmon Keyes during the years 1929 to 1934, and it was these men who gave the term LPF to this process. Miami at that time had considerable reserves of mixed sulfide-oxide ore.* In the development of a suitable treatment method, it was natural that leaching of the oxides with acid and the precipita¬tion of copper from the resulting copper sulfate solution by iron was investigated. The separation… • The term oxide as used in this article includes the copper oxides, carbonates, and silicates.

Jan 12, 1960

By Z. T. Bieniawski, E. Unal, H. Reginald Hardy

INTRODUCTION Rock bolts are a major means of support in underground coal mines in the United States. However, two of the most crucial problems facing the mining engineer today are that of finding a well defined and standard method for testing the anchoring ability of rock bolts, and of selecting the most suitable type of rock bolt and bolting pattern for a particular mine or specific mine section (Anon., 1982). Such selection requires not only an understanding of the behavior of the rock mass and the rock-bolt unit itself, but also a knowledge of the basic mechanisms by which rock bolts provide support while they interact with the rock mass during various field loading conditions. A recent study in this area has shown the inadequacy of present methods used in selecting and testing of rock bolts and the lack of clearly defined guidelines for safe and economical design of bolting patterns (Bieniawski, et al., 1980). The present paper describes a research study aimed at developing laboratory instrumentation and associated techniques for the evaluation of bolt-rock interaction. The instrumentation system developed, procedures followed during various experiments, and typical results from a series of studies carried out on mechanical bolts are presented. DEVELOPMENT OF THE ROCK BOLT TESTING FACILITY General A block diagram of the experimental facilities are shown in Fig. 1. The system consists of three main sections. The first

Jan 1, 1982

By Henry U. Ross

The behaviour during reduction of iron-ore pellets and sinters was investigated. Several methods for the preparation of agglomerates and their reduction were tried. Commercial agglomerates from world-wide sources as well as experimental samples were tested. The effect of coke additions to pellet and sinter plant feeds was given special consideration. An analysis of the test results has helped to explain many of the phenomena associated with the reduction of iron-ore agglomerates such as swelling, loss in strength and wear resistance, changes in porosity, changes in mineralogy and the formation of metallic iron and slag. A double-layer pellet with all of the coke concentrated in the core proved particularly interesting. Although large quantities of coke showed that partially reduced agglomerates containing metallic iron could be produced in the laboratory, the problem of producing reduced pellets and sinters by the existing agglomerating processes still remains.

Jan 1, 1977

By Benjamin B. Lawrence

The lease-system is the gradual result of the development of our larger producing mines throughout the State of Colorado. The operation of a mine, or group of mines, by corporations has been attended, in many cases, by disaster, owing to the difficulty of securing a fair day's work from the men employed in the mine, and the loss entailed by careless mining and sorting of high-grade ores, or by lax or inefficient management on the part of superintendents and foremen. Given, therefore, a mine that has been practically abandoned by its owner, for the reasons given, but still possessing merit, the lessee appears on the ground and secures a lease for a year, or term of years, from the owner, upon the payment of a royalty upon the gross smelter- or mill-returns of the ore which he mines. In this way many of our abandoned mines have been re-opened by the miner, who, with two or more associates, has been enabled, by careful attention, to obtain profitable results.

Jan 1, 1893

By R. L. Curfman

From January 1, 1965 through July 5, 1970, the very difficult potash ore body of Texasgulf Inc. near Moab, Utah was mined by conventional methods. The mine was gassy, the temperature was high and structural conditions precluded a satisfactory or economical extraction ratio due to the undulating configuration of the ore horizon. In 1966, 67, and 68, alternative mining methods were considered, among which was solution mining of the ore body. Cost studies indicated that the use of crystallizers to evaporate the large amounts of water attendant to solution mining offered no chance of economic success. In 1969 additional testwork and cost studies were carried out utilizing solar evaporation. These studies showed economic potential and justified additional investigation. As a result of these studies, Texasgulf now gathers potash solids from these solar evaporation ponds, (Fig. l), after pumping them from the underground mine as brine. The investigations were concentrated in four basic areas : (1) area evaporation rates and crystal growth habits; (2) underground solution tests including heat transfer rates; (3) accelerated evaporation tests to provide material for metallurgical testing, and (4) tests of evaporation pond lining materials and application techniques, along with area surveys to ascertain if sufficient earth was available in the near vicinity to con-

Jan 1, 1974

By G. S. Hume

Three provinces in Canada—New Brunswick, Ontario and Alberta— produce oil and gas in commercial quantities. In addition a small amount of oil is being produced and refined in the Northwest Territories at Norman on the Mackenzie River. The production at Norman is derived from two wells drilled by Northwest (Imperial Oil) Co. in 1920 and 1923. The refined products of the oil are used locally in connection with mineral developments on Great Bear Lake. The production of petroleum by provinces and the consumption of natural gas are shown in Table 3. In addition a small amount of natural gas is produced in the southwestern part of Manitoba from shallow wells for local use. Tables 1 and 2 give detailed information. The greatest drilling activity in 1933 in Canada centered around the southern end of the Turner Valley field, Alberta. In addition to several wells previously commenced in this area, eleven new wells were begun. There were three completions to the Paleozoic producing zone in 1933 in the southern part of Turner Valley and one well was abandoned as a result of being off the favorable structure. Of two wells completed in

Jan 1, 1934

By N. M. Raju, B. Singh

The paper seeks to present the results of experimentation in room and pillar stopes with different ground conditions to determine the safe working span. In the experimental stopes, ground movement was monitored with gradual widening of the room span. The field measurements included closure between the stope walls and the extent of ground movement in the hangwall using borehole extensometers. hock bolting was used as an exclusive support system which enabled introduction of scrapers for improving productivity. In one nine, phosphate bed, 3 to 3.5 m thick dipping at 45O and overlaid by weak laminated shale, was worked at shallow depth of cover. h the experimental panel, five s topes were worked with spans varying from 5.5 to 7 m. In the second mine, the chalcopyrite orebody up to 6 m in thickness dipping at 25 - 30" was worked at a depth of 1100 m. The hangwall consisted of fairly competent schistose rocks and therefore 10 to 15 m wide spans could be experimented. The field measurements confirmed that in the phosphate mine with weak shale roof, 7 m span could be safely worked with subsequent caving of the bolted roof. In the copper mine, 15 m span could be worked and the stopes required subsequent backfilling for better ground control.

Jan 1, 1983