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PRESIDENT MOSES: I thank you, Mr. Emrick. Mr. Shubart would like to supplement your paper with another article. SECRETARY SHUBART: My paper really should not supplement Mr. Emrick's paper, because I secured some data from him, I knew Mr. Emrick had had a great deal of experience in shearing and I thought he could give you some useful data. (Here Mr. Shubart read the following:) "For the past two years, there has been considerable discussion among coal mining men concerning the advantages of a shearing cut in addition to the undercut, in mine work. We have had a number of requests for information on sheared coal. We were asked questions like these: What percentage increase in lump can be obtained from sheared coal? What has been the experience of mine men who have employed the shearing cut? Is the shearing cut a means of increasing the lump content? If so, is it increased to such an extent as to warrant the installation of shearing machines? Upon investigation it was found that no one could give us any definite information on the subject as no one had weighed separately the grades of coal produced from' the shearing cut. With a view of getting this information first-hand, the Goodman Manufacturing Company built up a shearing machine to be used in experimental work only. The officials of the Troy Coal Company were eager to share in the expense of obtaining this information, so that in May of this year we shipped to their mines our first type 319 shearing machine. The Troy Coal Company operates a mine at Troy, Illinois, in the No. 6 seam and produces about 275 tons daily. The coal seam averages five and one-half feet in thickness. Previous to the arrival of the shearing machine the coal was undercut six feet deep by a' Goodman Shortwall Machine. To break down the coal required two shots in the entries and three in the rooms. The percentage of lump measured over two-inch screens, averaged 58.2 per cent. The conditions of the mine were very favorable for obtaining accurate weights on the amount of lump and slack coal run over the shaker screens. The shearing machine easily cut the entire tonnage of the mine so that all coal dumped into the railroad cars had been produced from a shearing cut, in addition to an undercut. Accurate records were kept of the railroad weights and front this data the percentages of lump and slack were computed. During the month of June the percentage of lump produced over two-inch shaker screens was 69.9 per cent. This result demonstrated that the introduction of the shearing cut had increased the percentage of lump twenty per cent. The entries were driven ten feet wide and the rooms thirty feet wide The shearing cut was made near the center of the face in all places. A hole was drilled in each rib and the coal shot down with one-half the powder required when the places had been undercut only. The coal was broken down to the back of the cut so that very little pick work was necessary to load it out. The benefits derived from the shearing cut were as follows: 1. Increased percentage of lump, thus increasing the average price of coal per ton. 2. Preservation of a tender top due to the decreased amount of explosive used. 3. Facilitated handling of coal by the miner thus increasing the tonnage per man. 4. Eliminated coal yardage in entries and crosscuts of ten feet or less in width for the reason that the shearing cut provides a loose end from which to shoot the coal. This applies to the union fields only, as the non-union mines do not pay for coal yardage. Based on a price of $2.50 for lump coal and $1.25 for slack coal, the average price per ton was increased

Jan 1, 1926

By S. F. Guo, Z. F. Zhan, X. L. Huang, Y. Zou, S. W. Qi

"FLAC3D is an important numerical analysis software to study dynamic response of rock slope. In application of the program, the common issues such as absorbing boundary and the method to apply wave have been well studied. However, effects of model mesh size, damping and width of slope are still unknown. In order to make the result more convictive, this article has discussed the above issues systematically. It found that when the maximum mesh size is smaller than 1/10~1/8 of the smallest wavelength, the mesh size is smaller, the computational accuracy is higher. Meanwhile, values of damping and width of slope have no effect on the result. Additional, results of FLAC3D modeling on wave transmission across rock joints agree well with analytical solutions, so it has verified the capability and accuracy of FLAC3D on dynamic response of rock slope.INTRODUCTIONChina is a mountainous country accompanied with many earthquakes. Thousands of geological disasters are triggered by the Wenchuan Earthquake in Sichuan Province, and the majority of the disasters are landslides induced (Xu et al., 2009). Meanwhile, the paper (Li et al., 2003) points out five significant issues about dynamic loading in the area of geotechnical engineering, which includes the study of rock slope stability under earthquakes, and the dynamic response of rock slopes is one of its important study issues."

Jan 1, 2015

CONTENTS PAGE SOUTHWARD, GLENN B.-Coal Mining by the V System. Discussed by Glenn B. Southward, Howard N. Eavenson, Edward B. Raiguel, Thomas de Venny, J.. J. Rutledge, Graham Bright 1 ARMS, RAY W.-Dry Cleaning of Coal. Discussed by Ray W. Arms, S. A. Taylor, Howard N. Eavenson, W. R. Crane, F. F. Jorgenson, G. R. Delamater. 6 EAVENSON, HOWARD N.-Data About Labor Employed in Various Bituminous Coal Mines. Discussed by Howard N. Eavenson, George H. Ashley, E. A. Holbrook, S. A. Taylor, R. V. Norris 14 Coal Mining by the V System Discussion of the paper of GLENN B. SOUTHWARD presented at the New York Meeting, February, 1924, and issued as Paper No. 1300-C, with MINING AND METALLURGY, February, 1924. MEMBER.-How do you pay your men for loading? GLENN B. SOUTHWARD.-Everything is on time basis. MEMBER.-How many men do you have loading across one of the diagonal faces? GLENN B. SOUTHWARD.-From four to five, depending on the length of the face. Our loaders are so arranged that each will give about twenty-five tons per loader a day. MEMBER.-How much timber do you use? GLENN B. SOUTHWARD.-A little more than will be used in room-and-pillar work, but not a great deal more. We have not attempted to recover much of our timber. MEMBER.-IS the mine union or non-union? GLENN B. SOUTHWARD.-Non-union. HOWARD N. EAVENSON, Pittsburgh, Pa.-I went .through that mine some weeks ago, and think that the author has been very conservative in his statements about the amount of loadings, etc. EDWARD B. RAIGUEL, Huntington, W. Va. (written discussion).¬Page 7 shows 60 men employed in day and night shifts, inside the mine, producing 750 tons per day. Let us reduce these figures to a man-hour basis, for comparison with Mr. Eavenson's figures on West Virginia mines, as follows:

Jan 6, 1924

By H. M. Howe

PART I. INTRODUCTORY. § 24. INTRODUCTION.-This paper discusses the chief existing data as to the temperature, in iron-carbon alloys, of Ae.3, the upper limit of the transformation range when in equilibrium, as distinguished from Ac3, the temperature at which the end of the transformation is noted in heating up, and from Ar3, that at which its beginning is noted in cooling down. The former is in fact carried above Ae3 and the latter below Ae3 by lag. I touch incidentally on the influence of manganese on Ae3 (§ 29, p. 1102). The sections, tables, and illustrations, are numbered consecutively with those in the accompanying papers by Howe and Levy on Determination of, the Position of Ae3 in Carbon-Iron Alloys, and by Burgess, Crowe, and Rawdon on Thermal and Microscopical Examination of Professor Howe's Standard Commercial Steels, to which the present paper forms a sequel. § 25. The contradictoriness of our present evidence is shown by grouping it together in Fig. 14. For instance, both Goerens and Meyer (Series 2) and Meuthen (Series 12) used practically stationary temperature, and thus reduced the influence of lag very greatly; yet Ae3 for 0.32 carbon steel according to the former investigators is 894°, but according to Meuthen it is at or below 770°, a discrepancy of 124° or more. In view of our ability to measure these high temperatures within a few degrees, the existence of such a discrepancy is as unwelcome as it seems needless. I attack the thankless task of bringing some order out of this chaos.

Jan 6, 1913

By Ruiling DU, Jiazhi Zhang, Yong Zhao, Keng Wu

Reaction kinetics of metallurgical physical chemistry which was successfully applied in metallurgy (as ferrous metallurgy, non-ferrous metallurgy) became an important theoretical foundation for subject system of traditional metallurgy. Not only the research methods were very perfect, but also the independent structures and systems of it had been formed. One of the important tasks of metallurgical reaction engineering was the simulation of metallurgical process. And then, the mechanism of reaction process and the conversion time points of different control links should be obtained accurately. Therefore, the research methods and results of reaction kinetics in metallurgical physical chemistry were not very suitable for metallurgical reaction engineering. In order to provide the definite conditions of transmission, reaction kinetics parameters and the conversion time points of different control links for solving the transmission and reaction equations in metallurgical reaction engineering, a new method for researching kinetics mechanisms in metallurgical reaction engineering was proposed ,which was named stepwise attempt method. Then the comparison of results between the two methods and the further development of stepwise attempt method were discussed in this paper. As a new research method for reaction kinetics in metallurgical reaction engineering, stepwise attempt method could not only satisfy the development of metallurgical reaction engineering, but also provide necessary guarantees for establishing its independent subject system.

Jan 1, 2015

CONTENTS PAGE MERRISS, M. H.-Direct Electrolysis of Black-copper Anodes of High Nickel-lead Content. Discussed by C. S. Witherell, C. P. Linville, G. E. Dalbey, M. H. Merriss 1 GRISWOLD, GEORGE G.-Calculating the Zinc for Desilverizing Lead Bullion by the Parkes Process. Discussed by C. S. Witherell, George G. Griswold, Milo W. Krejci, Lawrence Addicks, W. F. Gross, H. H. Alexander, A. F. Beasley, C. P. Linville 3 ALEXANDER, H. H. and STACK, J. R.-The Reduction and Refining of Tin in the United States. Discussed by Edward F. Kern, J. R.' Stack, R. L. Hallett, C. R. Hayward, William H. Bassett, R. C. Canby, H. G. S. Anderson 20 GREENAWALT, WILLIAM E.-Greenawalt Electrolytic Copper Extraction Process. Discussed by Stuart Croasdale, Colin G. Fink, Arthur L. Walker, Edward F. Kern, Henry A. Tobelmann, Oliver C. Ralston 26 BENEDICT, C. H. and KENNY, H. C.-Ammonia Leaching of Calumet and Hecla Tailings. Discussed by G. E. Dalbey, C. H. Benedict 34 RALSTON, OLIVER C.-Hydrometallurgy of Lead. Discussed by F. L. Bosqui, Jr., George D. Van Arsdale 34 TAINTON, U. C. and LEYSON, L. T.-Electrolytic Zinc from Complex Ores. Dis¬cussed by W. G. Woolf, C. A. Hansen 39 Direct Electrolysis of Black-copper Anodes of High Nickel-lead Content Discussion of the paper of M. H. MERRISS, presented; at the New York Meeting; February, 1924, and, issued, as Paper No. 1273-M, with MINING AND METALLURGY, September, 1923. C. S. WITHERELL, New- York, N. Y. (written discussion).-This paper is particularly valuable in that it gives the results of operations -carried out under conditions differing from standard practice. In the electrolytic refining of copper, as in other kinds of metal refining, it is occasionally necessary to treat extraordinary foul or complex material, in which cases 'it is valuable to know what other metallurgists have accomplished under similar conditions. As tapping the slimes-covered anodes brought the tank-voltage down to 0.45 to 0.50 volt, the counter electromotive force was, probably not more than 0.1 or 0.2 volt; hence the so-called polarization was, mainly,

Jan 6, 1924

CONTENTS PAGE CARMICHAEL, NORMAN, and KIDDIE, JOHN.-Development of Mine Transportation in Clifton-Morenci District. Discussed by Norman Carmichael, Charles Legrand, B. B. Gottsberger 1 BARER, THOMAS C.-Fresnillo - Glory-hole Mining Practice. Discussed by Charles A. Mitke, B. B. Gottsberger, E. R. Thomas, Enoch Perkins..: 3 BRADLEY, P. R.-Estimation of Ore Reserves and Mining Methods in Alaska Juneau Mine. Discussed by R. M. Raymond, A. H. Rogers, Enoch Perkins, H. G. Moulton 6 BIRCH, STEPHEN.-Geology and Mining Methods of the Kennecott and Beatson Mines. Discussed by R. M. Raymond, Alan M. Bateman, Enoch Perkins 8 LEES, CHARLES E.-Mining Methods and Costs at the Iron Cap Copper Co., Copper Hill, Ariz. Discussed by A. L. Walker, A. Neustaedter 10 BELL, CHARLES N. -Mining Methods of the Telluride District. Discussed by Charles S. Hurter 10 Development of Mine Transportation in Clifton-Morenci District Discussion of the paper of NORMAN CARMICHAEL and JOHN KIDDIE, presented at the New York Meeting, February, 1924, and issued, as. Paper No. 1310-M, with MINING AND METALLURGY, March, 1924. NORMAN CARMICHAEL.-We realized the objections too the gable-bottom car, but were almost forced to its adoption by the same reasons that caused us to retain the 20-in. gage. To use another car would have meant a vast number of changes, for our transportation system was quite extensive; all mine chutes and ore bins were arranged for that car. Had we been laying out, new works, many of our decisions would have been different. MEMBER.-If you were planning it now, would you not put in box bottom cars with a rotary dump? NORMAN CARMICHAEL.-We surely would. One objection to the gable-bottom car is the spill. No, matter how carefully the cars are kept up,: there is always leakage and spill. The cost of keeping and maintaining the cars in a good state of repair, so as to keep that loss at a minimum, is not necessary for a box-bottom car.

Jan 6, 1924

CONTENTS PAGE BARTON, D. C.-The Eötvös Torsion Balance Method of mapping Geologic Structure (T. P. No. 50) 1 GEORGE, P. W.-Experiments with Eötvös Torsion Balance in the Tri-State Zinc and Lead District (T. P. No. 65). 15 LANCASTER-JONES, E.-The Computation of Eötvös Gravity Effects (T. P. No.75) HEILAND, C. A.-A Cartographic Correction for the Eötvös Torsion Balance-(T. P. No. 52) 17 SLICHTER; L. B.-Certain Aspects of Magnetic Surveying (T. P. No. 120). . . . 18 WEAVER, W.-Certain Applications of the Surface Potential Method (T. P. No.121) LUNDBERG, H.-Recent Results in Electrical Prospecting for Ore (T. P. No. 98). . 20 HOTCHKISS, W. 0., ROONEY, W. J. and FISHER, J.-Earth-resistivity Measure-ments in the Lake Superior Copper Country (T. P. No. 82) 21 LEONARDON, E. G. and KELLY, S. F.-Some Applications of Potential Methods to Structural Studies (T. P. No. 115) 23 MASON, M.-Geophysical Exploration for Ores (T. P. No. 45) 25 The Eötvös. Torsion Balance Method of Mapping Geologic Structure Discussion of the paper of D. C.. Barton, issued as Technical Publication No. 50 with Mining and, Metallurgy, February, 1928. D. C. BARTON.-The field surveys which I have been privileged to use as illustrations for this paper were done for Mr. DeGolyer's companies and were released through his favor. W. J. MILLARD, Tulsa, Okla.-Has any oil been found by the torsion balance in West Texas? D. C. BARTON.-NO new oilfield has been discovered on the basis of torsion balance work. It has had some part in controlling the policy of certain companies in playing the extension of known oil fields. A number of "T. B." structures have been drilled and dry holes obtained. Of those known to the writer, one apparently was a structural high, one is a broad general high but locally low and probably is a deep-seated structural high, one seems normal although the control is poor, and one was considered structurally low but is now suspected by some geologists of being structurally high. E. L. DEGOLYER, New York, N. Y.-A large gravity structure, generally referred to, I believe, as the Crosby County Structure, has been found in West Texas. This structure is perfectly symmetrical with the arrows all pointing toward a common center, very much like the Nash salt-dome pattern in Dr. Barton's paper (Fig. 9). One of the peculiar things about it, from the standpoint of the gravity high, is that it is so

Jan 1, 1928

CONTENTS PAGE ANDERSON, ARVID E., and CAMERON, FRANK K.-Recovery of Copper by Leaching, Ohio Copper Co. of Utah. Discussed by Thomas B. Brighton, H. C. Goodrich, Arvid E. Anderson, Thos. P. Billings, Frank K. Cameron 2 BEESON, J. J.-Mining Districts and Their Relation to Structural Geology. Discussed by Charles Keyes, Chas. A. Porter 4 DOBBEL, CHAS. A.-Deep-hole Prospecting at the Chief Consolidated Mines. Discussed by G. W. Crane 10 CRANE, G. W.-Notes on the Geology of East Tintic. Discussed by G. W. Crane, H. E. Havernor, N. O. Lawton 11 SACKETT, B. L., BARDWELL, CARLOS, JACOBSON, SIMON, and JENSEN, N. H. Lead Smelting in Utah. Discussed by D. W. Jessup, B. L. Sackett, E. H. Laws 13 BARDWELL, E. S., and MILLER, Roy H.-Pulverized Coal as Fuel for Copper Refining Furnaces. Discussed by L. D. Anderson, E. S. Bardwell, C. P. Crawford 15 WIGTON, G. H.-The Chief Consolidated Volatilization Process and Mill. Discussed by Thomas Varley, S. G. Olmstead, V. O. Lawton, O. C. Ralston.... 16 JESSUP, D. W.-Evolution in the Preparation of Ores for Lead Blast Furnaces. Discussed by W. Spencer Reid, D. W. Jessup, Carlos Bardwell 19 ALLEN, H. P., and MADGE, WM. C.-Chloridizing Mill of the Standard Reduction Co. Discussed by Thomas Varley, H. R. Hanley, H. P. Allen, George H. Dern 20 TUCKER, E. L., and HEAD, R. E.-Effect of Cyanogen Compounds on Floatability of Pure Sulfide Minerals. Discussed by Blarney Stevens 24 Mix, B. E., and BARKER, L. M.-Method of Unloading Ores and Coarse-crushing Practice at Magna Plant of Utah Copper Co. Discussed by W. C. Madge,B. E. Mix 25 KEIGLEY, C. T.-The New Byproduct Coke Plant of the Columbia Steel Corporation. Discussed by W. M. Grant, C. T. Keigley, A. C. Feilder 25 JACKSON, P. W.-Blast Furnace Plant of the Columbia Steel Corporation. Discussed by W. R. Phibbs, H. M. Henton 26 OLDRIGHT, G. L., KEYES, H. E., and WARTMAN, F. S.-Production of Ferric Sulfate and Sulfuric Acid from Roaster Gas. Discussed by G. D. Van Arsdale William E. Greenawalt, G. L. Oldright 27 MAZANY, M. S.-Braden Copper Company Caletones Smelter. Discussed by A. B. Young, G. L. Oldright 36 HARRINGTON, D.-Safety Methods in Utah Coal Mines. Discussed by Edward K. Judd, Otto Herres, Benedict Shubart, A. C. Watts, D. Harrington 36

Jan 12, 1925

This paper will be a discussion of the geological exploration and drilling carried out on the Mt Davy Block, Greymouth Coalfield. A brief summary of the geology of the Greymouth Coalfield will be given to put the Mt Davy Block into perspective.

Jan 1, 1979

By A. C. Callen

This, report represents the comments of the individual members of the A. I. M. E. Sub-committee on Physics of Mine Ventilation on the proposals of a special committee of the Institution of Mining Engineers (London). As might be expected, there is a certain diversity of opinions, for owing to the shortness of time- it was not possible for the sub-committee to get together for informal discussion. The report is presented in this form in the hope that it will bring out a full discussion by other members in the Institute. OLE SINGSTAD?, New York, N. Y.-The Atkinson formula, P =SV2 K a is quoted and it is stated that this formula is especially applicable to mine galleries but is unwieldy in application, as in many problems the value of K, S and a are assumed not to change. This is the same formula that was used during the preliminary calculations for the ventilation of the Holland Tunnel, and where the above-mentioned values were constant for a number of cases, it was a very simple matter to rewrite the equation n the form P = K1V2 and avoid the repeated use of identical figures. The Atkinson formula assumes 1. That resistance to flow is independent of the pressure. 2. Changes in volume due to change in pressure may be neglected. 3. Changes in density and viscosity may be neglected. 4. That the coefficient K is a constant. 5. That P is proportional to V2. We found, from our experiments in connection with the ventilation of the Holland Tunnel, that all the above assumptions could be safely made, with the exception of No. 3, and No. 4 at, very low velocities. In mine work, where many assumptions must necessarily be made, it would seem inconsistent to attempt to make any allowance for the other factors, which are so small that they can be determined only by the most careful experimental work. However, P does depend directly on the density of the air, and to that extent the Atkinson formula is incomplete.

Jan 2, 1926

PRESIDENT PRYDE: Any discussion on Mr. Poster's paper? MR. J. BEVAN: I would like to ask the gentleman how fine the dust has to be to cause an explosion? MR. T. FOSTER: According to the Bureau of Mines, it is claimed coal passing through a 100 mesh screen would be considered fine enough. That is all I can learn from the different bulletins. MR. BEVAN: Will the coal dust be that fine; going back in the empty cars on the tipple in the mine? MR. FOSTER: Possibly a great deal of it would be. MR. BEVAN: Will the coal dust be that fine, going back, in the empty the coal dust going back in the cars on the tipple, and into the mine? MR. FOSTER: In some places, they are wetting the cars at the tipple, -in the Rock Springs District, we have as the trip goes out, they have a big pipe, and they souse the car, and wet the load, and in some places, near the timbers; that helps to a certain extent. That does not absolutely eliminate it all, but it helps considerable. MR. WM. LITTLEJOHN (Utah Fuel Company) : I think we have all listened very attentively to the paper that Mr. Foster has just read. He has brought up a subject rather close to my heart, for a long time. He mentions particularly, the Scofield disaster, which happened the first of May, 1900; two hundred men lost their lives in the explosion; and I think it is generally conceded that is about the first time it had ever been brought to the attention of coal miners or operators that such a thing was possible, namely, a purely coal dust explosion. The term "Scofield disaster" is rather a mistake, in a way; while the mine that exploded at the time is in the Scofield District all right, it is now known, and probably was known at that time, as the Winter Quarters Mine, one of the mines which belongs to the Utah Fuel Company at the present time, and did at that time. This mine

Jan 1, 1924

it may be clearly seen that one of the most rapidly increasing items in mining operations is the cost of the timber alone, to say nothing of the cost of installation. Consequently, any practical means that may be used to lengthen the life of mine timber will greatly tend to decrease mining costs and result in important economies in operation. The four principal agents by which mine timbers are destroyed are, decay, insect attack, fire and mechanical abrasion. Decay and insect attack are credited with more than 50 per cent of the total amount of timber destroyed in the mines. Numerous methods may be used to conserve mine timbers, such as better selection, preparation, storage and segregation. It frequently happens that good timber goes into places where poor timber would do as well, and timber of inferior quality is sent into places where only the best grade should be used. However, the most effective method of conservation is by treatment with some standard preservative to prevent decay. Some of. the benefits to be noted from the use of preserved timbers are; the reduction in operating costs by decrease in timber purchases; cuts down interference with mining operations due to timber failures on main haulageways; prevents excessive falling of roof in entries by maintaining timber in sound condition; conserves timber supplies and makes possible the utilization of inferior woods; reduces the danger of mine accidents; improves mine ventilation; lessens fire hazard. Our experience thus far with preservatives, while not of a sufficient period of time to establish just what length of life we may obtain from timber so treated, results obtained during the past four years indicate that the intelligent use of preservatives will effect sufficient economies in mine timber costs to justify the expenditures made for this purpose. MR. BAKER (Concluding): Now, if there are any questions you gentlemen would like to ask about our particular operations, I will attempt to answer them. J. H. EMRICK (Sullivan Machinery Company, Denver, Colo.) ; I was wondering how much penetration you get. MR. BAKER: We get between one-sixteenth and one-eighth of an inch; it is a dipping process. With pressure treatment you get-a greater absorption; that is, better than one-sixteenth of an inch. As long as there is no mechanical abrasion, it seems to serve the purpose. MR. EMRICK: Does that apply to the condition of the timber before it is treated? If it is perfectly dry, will it absorb more treatment than if it is partly green? MR. BAKER: Certainly; one of the things we do is to have it thoroughly seasoned before it is put into the preservative. We put some green timber into the mine once, and the fungus went after it right away. MR. EMRICK: What was the difference in the depth reached by the preservative? MR. BAKER: It hardly penetrated at all when it was green. It has to be sound and well seasoned. MR. EMRICK: How long was the timber dipped or treated? MR. BAKER: According to the seasoning. If it was well seasoned, it was left in the hot bath for an hour; if not so well seasoned, it was left for about a couple of hours. C. M. BILLINGTON (General Superintendent, Rocky Mountain Fuel Company, Lafayette, Colo.): Have you found it necessary to treat timber that has been charred? MR. BAKER: No. However, I suppose it has the sane effect; in lots of places they char timber for the purpose of treatment. MR. BILLINGTON: Have you ever tried lime and salt? MR. BAKER: No, this is the only thing we have tried, the creosote and the Aczol; the Aczol is a foreign product. WM. LITTLEJOHN: Which I is preferable, the Aczol or the creosote? MR. BAKER: I couldn't say as to that. MR. LITTLEJOHN: Have you had any tests as to the value of either? MR. BAKER: We have had some of the Aczol timbers in service for a little over four years; we have had some creosote timbers in service

Jan 1, 1926

forated, allowing the completion of the removal of wash water. When discharged into the washed nut bin, the coal is moist but carries so little water as to not be objectionable to the trade, nor to give any difficulty from freezing during the coldest weather. The rock and bone from the primary jigs is elevated to a 15-ton bin by means of a single strand scraper conveyor 40 feet center to center operating on a 45 degree incline, carrying 12" x 5" scrapers every two feet. This conveyor travels at a speed of 100 feet per minute and has a capacity of 17 tons per hour. From this bin, this material falls into the third or rewash jig similar in all respects to the first two, which discharges the rock waste directly into a 15-ton refuse bin below and the bone into a short dewatering conveyor which delivers into a similar 15-ton bin from which the bone is taken to the powerhouse. The oversize and water from the shaker screen, the water from the dewatering conveyor for both the washed nut and bone, and the sludge and wash water from the three jigs, are delivered by launders to the first compartment of a three-compartment settling tank. Most of the coarser broken coal is deposited in this tank, from which is it continually removed by a bucket elevator carrying 8" x 5" perforated buckets operated on a 60 degree incline at 200 feet per minute, capable of delivering 25 tons per hour to the 50-ton washed coarse slack bin. The water passes successively through the three compartments of the settling tank and from thence through a six-inch pipe to a centrifugal pump, circulating 900 gallons per minute against a 32-foot head. A four-mesh screen 30" x 72" in the third compartment of the settling tank removes the chips of wood, paper, and the other trash, which otherwise would accumulate in the water. Water is provided from the camp water system, deriving water from the well located in an arroyo bed. During the summer months just passed, the water used, has been 108 gallons per ton of raw nut, or 146 gallons per ton of washed nut. The water meter had not been installed last winter, but it is estimated that operating at capacity, the washery will be found to require only about 75 to 100 gallons per ton of raw nut. It has not been found necessary, nor advisable, to attempt to dry the sludge from the settling tank, nor to save the water from leakage of the tanks and bins. The sludge from the jigs is washed into the settling tank and the sludge from the settling tank is washed through a tile drain to the arroyo. The jigs, shaker screen, circulating pump, washed slack elevator, and the rock handling conveyor, are all driven from line shafts driven by one 40 H. P. motor, each jig driven through a clutch. The belt conveyor and the washed nut conveyor, have separate motor drives of five and seven and a half H. P. respectively. The washer is housed in a corrugated iron building, which is partially heated by steam coils. One attendant is required for operation, regulating the feed of the jigs, the supply of water, removal of the rock, and oiling and maintaining the machinery. The rewash jig is operated only intermittently. About eleven per cent by weight of raw nut is removed as waste and four per cent goes to the washed slack bin. No control analyses of the products have been made; the efficiency of the plant being determined only by the physical appearance of the products; but the washery has been a source of pride and satisfaction to all those connected with it. As mentioned before, it has caused no interruption of operation and it has assisted materially in creating an unprecedented demand for ALAMO nut. MR. CHARLES: If there are any questions, I shall be pleased to endeavor to answer them. MR. LITTLEJOHN: Mr. Charles, do I understand it is the nut only that is washed there? MR. CHARLES: Yes, sir. MR. LITTLEJOHN: What did you say the size was? MR. CHARLES: Through three inch round perforations, retained on

Jan 1, 1926

By J. Grubb

"The undertakings described in the paper titled “Study on correlation of quantified coal rank with self-heating temperature” by Wang and Luo in the November 2015 issue of Mining Engineering (Wang and Luo, 2015) are mathematically sustainable and an acceptable extension of work performed by Smith and Lazzara (1987) for the U.S. Bureau of Mines. The paper is not an accurate explanation of the currently accepted leading practice for determining the propensity of a coal seam for spontaneous combustion. The paper could lead a practitioner to an oversimplified conclusion on how to determine the propensity of a coal seam to spontaneously combust.The spontaneous combustion of coal is a complex and not fully understood reaction. What is understood is that many more factors other than selfheating temperature (SHT) and coal rank are required to sufficiently evaluate the risk of spontaneous combustion in a particular coal seam. A superficial assessment can lead to an improper response to the risk. Some statements on the next steps through an appropriate literature search would have made the authors’ conclusions more credible.The SponCom 2.0 software, updated by the National Institute for Occupational Health and Safety (NIOSH) in 2011, provides a path for evaluating the susceptibility of a coal seam to spontaneous combustion. In addition to proximate and ultimate analyses to establish coal rank, and therefore an estimate of SHT, the program includes the history of heatings, friability, seam thickness, overburden thickness, rider seam presence, pyrite presence, face and butt cleat densities, geothermal source presence and other geological features in the assessment. Mining conditions including floor heave, rib sloughage and rate of advance are also assessed to conclude a propensity for spontaneous combustion."

Jun 1, 2016

By V. M. Troughton

Further pile load testing has been carried out at Canary Wharf to compare the performance of base grouted and ungrouted bored piles founded in the Thanet Sand. The testing regime included three preliminary test piles and two working test piles. The results of these tests are summarised in Table 1 below. Two of the preliminary test piles were located only 14m apart to compare the performance of a base grouted and ungrouted pile in similar ground conditions. The load/settlement behaviour of these two preliminary test piles are compared on Figure 1. All the piles were drilled under bentonite with a drilling bucket. In the base grouted piles four grouting tubes were placed with the reinforcement cage to within 500mm of the pile toe. After the pile had been concreted these grouting tubes were then extended to the pile base by drilling and packers were installed. Grout was then injected into the four tubes simultaneously.

Jan 1, 1991

Discussion at the The Midland Counties Institution of Engineers' general meeting, held in Nottingham on 6th May 1916, included contributions by Bramall E., Bragge G.S. and Watkins W.G. regarding possible measures for reducing energy consumption in coal-winding and pumping by centralising engines, using exhaust steam, improving coal quality and size uniformity, or mechanical stoking

Dec 1, 1916

D. EPPELSHEIMER, * Middletown, Ohio.-The housing of employees has so many and so varied aspects that in order to reach even an approximately correct solution it is necessary to have in mind a few fundamental principles; but it is not possible as yet to write these housing principles in the clear and correct form that is possible with many of our natural laws. Manifestly, the problem depends first on the kind of people it is necessary to house. What is suitable for the Southern unattached negro is not suitable for the married skilled American. The influx of colored labor has affected quite a number of what were satisfactorily housed communities. The second important factor is the relative proportion of the number of employees to the total employable population of the community in which the industry is located. The employer of a hundred men in. a large city has little responsibility in the matter of housing his employees. If he employs 75 per cent. of the employable population in a community of 27,000, as is the case of the company with which the writer is connected, it means a large responsibility. In the establishment of an entirely new plant in a more or less isolated place, the responsibility becomes greater. As engineers, we design and write the specifications for the machinery to accomplish a definite purpose, and proceed to house it, provide the necessary buildings with their accessories in the way of cranes, or heating systems, or sprinkling systems, as the case may be. There is no reason why the operating force should not be built up in very much the same way: design the organization, write its specifications so that the employment department can secure the proper men, and then house that organization with just as much thought and care as is given the plant. In the plant, the various machines will work along certain definite lines and accomplish certain results; but even if we start with the proper organization it takes considerable time to get that organization working together. One of the most important elements to this end is the proper housing of the organization. A man usually spends more time at home than at work. Proper surroundings and a comfortable, convenient house of good appearance exercise an influence that cannot be denied, and an employee situated in such surroundings is far more inclined to follow the policies of his employer and take an active part in furthering them

Jan 5, 1919

(The paper by L. H. De Wald-Tech. Pub. No. 429 was presented at the Boston meeting, September, 1931.) W. A. SCHEUCH, Chicago, Ill.-Since starting up our Hawthorne copper wire plant we have found that wire bars from certain suppliers perform quite differently from those of other suppliers. In attempting to evaluate these bars, we made cross-sections, and in making these cross-sections we found considerable variation in the crystal structure. Indications were that there was some preference in the type of crystal structure. In attempting to find the reason for that we discussed it with the various producers and-also reviewed the literature. Mr. DeWald was assigned to determine the various factors that enter into copper wire bar crystal structure, on the basis that the product was a horizontally cast wire bar of practically identical composition and of recognized good composition for the present quality product sold in the market. Mr. DeWald has asked me to say that he should have made reference to Mr. Dalzell's paper on a theory concerning gases in refined copper. D. K. CRAMPTON, Marion, Conn. (written discussion).-Mr. DeWald has set forth an interesting and thorough exposition of the factors controlling macrostructure of this material. It is particularly interesting to us as it somewhat parallels work we have done on macrostructure of round copper billets for piercing into tubes. Our findings as to the effect of the several variables on macrostructure check Mr. DeWald's. The general principles underlying the two are precisely the same. The fact that we worked with copper deoxidized with phosphorous instead of tough-pitch copper, and round billets cast on end instead of wire bars, does not influence the results. We have found that round billets cast so as to produce large radial grains have greater soundness and density than those with a fine macrostructure. Further, and more important, we have found that the billets with large radial grains show markedly different performance on piercing from those having a fine equiaxed structure. With a given temperature of billet and adjustment of piercing machine, the coarse-grained material requires appreciably lower power for piercing and goes through the operation inn appreciably less time. These two differences are of sufficient commercial importance to warrant exercise of great care in maintaining the coarse structure. It seems probable that much the same phenomenon should hold in the hot rolling of tough-pitch wire bars. We would expect that, other things being equal, the coarse-grained wire bars would roll more readily and require less power than fine-grained ones. Moreover, we believe the differences in initial structure of the wire bars should be largely eliminated in the hot rolling process and during the subsequent drawing and annealing, of wire would be entirely eradicated.

Jan 1, 1932

By S. H. Logan

Mr. B. Neilly: A week or so ago the Secretary was good enough to forward me an advance copy of this paper by Mr. Logan and it was suggested that I comment on it at this meeting. At that time I was not very certain that I would be here, so I committed my thoughts to paper. As a matter of courtesy to Mr. Logan, I sent him a copy of my proposed remarks and I would like to give you just what I sent to him. Appreciating fully Mr. Logan's ability and many sources of information, one naturally hesitates to question anything seriously set forth as his considered opinion. Neither does one of my political stripe like to accuse him of being too 'conservative.? However, in places his paper reminds me of another general manager of a Canadian bank. While I was still Secretary of the Ontario Mining Association, this general manager wrote asking for our forecast on the current year's mineral production, stating that he proposed to refer to such production figures in his annual address to his shareholders. The request was considered very complimentary to the Ontario Mining Association and, in my opinion, justified a great deal of serious study and effort. Finally, the estimate was prepared and forwarded, showing a modest increase over the previous year's total. Picture our surprise and chagrin on reading his address to find that he predicted not an increase but, if you please, a decline of over $10,000,000. Before I cooled off I wrote asking the basis of such a prediction and got a reply to the effect that men in his position had to be ultra conservative in picturing the future.

Jan 1, 1931