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At the end of June, 1938, a new oil field was opened in Egypt, the Ras Gharib. Five wells were completed during the year and gave a total production of 512,988 barrels.' In the Hurghada field production was as follows: Hurghada Field Age of field to end of 1938, years..................... 25 Producing area for gas and oil, acres................ 1,050 Barrels1 Total oil production to end of 1938............... 31,207,754 Total oil production during 1937................ 1,141,356 Total oil production during 1938.................. 1,019,520 Average oil production per acre to end of 1938... 29,719 Average oil production per acre-foot to end of 1938. . . 243.6 Daily average: production in December 1938.......... 2,603.54 Daily average production per well in December 1938. . 34.90 Millions Cu. Ft. Total gas production (Aug. 1925 to end of 1938)... 4,356.7 Total gas production during 1937.................. 222.5 Total gas production during 1938....... . 167.6 Maximum gas daily average of 1938 (ill May 1..... 0.6 Wells Number of producing wells completed to end of 1938 . . 100 Number of producing wells completed during 1938..... 3 Number of wells abandoned during 1938.............. 2 Producing wells at end of 1938 (all pumping)......... 78 Abandoned wells at end of 1938...................... 22 Dry wells at end of 1938......................... 21 Feet Average depth of bottom of producing horizon........ 1,720 Average depth of top of producing horizonlt 1,598 Character of oil, approximate average ill 1938: specific gravity at 60" F'., 0.900; base, mixed. Character of gas, approximate average for 1938: gallons gasoline per 1000 cu. ft. of gas, 6.4. Main producing formation: Nubian sandstone, Cretaceous (PI; sand rock and sandstone.

Jan 1, 1939

By Oliver Bowles

THE inorganic non-metallic minerals, that is, the non-metallics exclusive of coal, oil, gas and related minerals, constitute the basic raw materials for a number of essential industries. It is estimated that the value of the raw materials in this group produced in 1919, together with certain of the primary products ordinarily manufactured at the mine, exceeded $800,000,000. They are employed chiefly in the building, agricultural, and chemical industries. It has been estimated, by the Bureau of Mines, that approximately 00,000,000 worth of non-metallic minerals and their products were used in the building trades during 1918; with the great increase in building since that date and the increased cost of materials, the value of non-metals used in such industries during 1920 probably exceeded $500,000,000. The chief of these materials are cement, building stone, crushed stone, sand and gravel, clay products, lime, gypsum, glass materials, slate, talc and soapstone. In many of the producing industries of this great group, the waste is so great that the expense of handling it is an important item in the production cost. The utilization of waste is receiving unusual attention in many of the non-metallic industries at present. The most obvious advantages of such utilization are: (1) Conservation of mineral resources, (2) the removal of waste heaps that in many places obstruct development, (3) manufacture of new and useful products, (4) reduced production costs through elimination of a large part of the item of waste-disposal expense. In many industries there is keen competition between producers of various products used for the same purpose, so that advantage will accrue to the manufacturer who is able to reduce his production costs.

Jan 1, 1921

By T. Sterry Hunt

THE essential principle of this new process, now in operation in Chili and in North Carolina, for the extraction of copper from its ores, is the dissolving of the oxides of copper by a hot solution of protochloride of iron and common salt. In the action which takes place, the protochloride of iron is converted into peroxide, while the oxides of copper are changed into protochloride and dichloride, the latter of which, though insoluble in water, is readily soluble in a hot strong brine. From the solution thus obtained, metallic iron throws down the copper in a metallic state, regenerating the protochloride of iron; which is then ready for the treatment of a fresh portion of oxidized copper ore. In the case of slimy ores, the contact of the bath with the ore is effected by agitation in tubs ; but when the ores are granular, lixiviation in large vats is equally efficient and simpler. The hot solutions, charged with chlorides of copper, are digested in tanks with scrap-iron, or better, are made to flow through covered channels containing the scrap-iron, and in their passage lose the whole of their copper; the reaction at the same time evolving so much heat as to keep up the temperature of the liquid. In order to prevent a certain loss of chlorine, which otherwise takes place from the production of some basic ferric chloride in the reaction between the ferrous chloride and the oxides of copper (both protoxide and dinoxide being generally present in calcined ores), a portion of sulphurous fumes from the roasting is made to pass through the regenerated bath before adding it to fresh ore. This has hitherto been effected by injection, with the aid of a jet of steam.

Jan 1, 1873

August 10 to 14, 1914, inclusive Headquarters will be at the Hotel Utah. The following program of the meeting has been arranged y the Local Committees: Monday, August 10.-Members and guests will register at the Secretary's desk in Room C-38, Hotel Utah, and receive the official badges, booklets and programs of the meeting. At 2:30 P. M., there will be an organ recital at the Mormon Tabernacle, after which members and guests will be taken for a trip around Salt Lake City in sight-seeing motor cars. At 8:30 P. M., the ladies will assemble in the lobby of the Hotel Utah, where they will be met by the members of the Ladies' Entertainment Committee, and will be taken for an automobile drive about the city. At 8:30 P. M., a technical session will be held in the ballroom of the Hotel Utah. The following papers will be presented: F. W. BACORN: An Amendment to Sales's Theory of Ore Deposition. C. W. GOODALE: Drumlummon Mine, Marysville, Mont. I. B. JORALEMON: The Ajo Copper-Mining District. STUART CROASDALE: Leaching Experiments on the Ajo Ore. FRANK R. VAN HORN: The Occurrence of Bournonite, Jamesonite, and Calamine at Park City. HOWLAND BANCROFT: Dip Chart. M. N. ALLING: Ancient Auriferous Gravel Channels of Sierra County, California. B. S. BUTLER AND H. D. MCCASKEY: Copper Ores of the New London Mine. GEORGE A. PACKARD: Rope Idlers in the Raven Shaft. ARTHUR CROWFOOT: Development of the Round Table at Great Falls. FREDERICK LAIST AND A. E. WIGGIN: The Slime-Concentrating Plant at Anaconda. W, L, AUSTIN: The Treatment of Copper Ore by Leaching Methods. W. L. AUSTIN: Leaching Copper Products at the Steptoe Works.

Jan 8, 1914

By Herbert A. Everest

Discussion of the paper of HERBERT A. EVEREST presented at the New York meeting, February, 1916, and printed in Bulletin No. 109, January, 1916, pp. 165 to 167. NEWELL G. ALFORD, Earlington, Ky. (communication to the Sec-retary*).-Mr. Everest's statement concerning the economies in a small coal mine has interested me very much. The majority of discussions on coal-mine economy omit the small operator and for this reason Mr. Everest's paper should lead to productive thought. I agree that close concentration of working places and constructive supervision of labor are two items of salvation to the small operator. It is also true that small mines often yield as much profit per capital invested as their larger neighbors. Mr. Everest also says that the small operator has so keen a regard for the inroad on his profits that even one extra day hand is an extravagance not tolerated, and this is rightly so. But, does not this earmark of the small operator in many cases offer a clue to his vital weakness? A credit balance is the acid test of success in any enterprise. With the small operator who owns practically all the capital stock this is particularly significant. He never takes his eyes off the market price and at the same time strains every nerve to cut down his payroll. In several cases I have noted that the resultant close supervision of labor was in fact too close. The "stitch in time" was not applied to the repair of this or that, with a decided increase to the cost of the work when it had to be done at the expense of cutting off the run when orders were on the books.

Jan 5, 1916

By G. B. Pryde

IN laying out a new mine, provision should be made for the ultimate recovery of as much coal in any given bed as is consistent with safety and economic mining. Though each mining district, if not each individual mine, has problems that make the adoption of any hard and fast rule impossible, certain basic principles are adapted to practically all conditions. One of the most vital is the provision for barrier pillars of ample dimensions to protect all haulage and permanent airways during the life of the property. Where conditions permit, room or butt entries should be driven on the strike or slightly to the raise and rooms turned at right angles to said entries. The width of rooms and room pillars is governed by conditions prevailing in the mines under consideration. A safe rule is: In advancing, extract not more than 25 to 35 per cent. of the entire seam; in exceptionally thick seams, considerably less than 25 per cent. should be taken. Rooms usually vary in length from 250 to 350 ft. (76 to 106 m.) with a barrier pillar of not less than 80 ft. between the last crosscut in rooms, and entry and room crosscuts should be driven on sights; room crosscuts should be driven at right angles to the direction of the rooms. In mines under excessively heavy cover or where roof conditions are bad, rooms should be driven narrow and a barrier pillar left at every fifth to tenth room. This barrier should be of such dimensions that one or more rooms, with pillars of usual dimensions, may be turned through it when the barrier is no longer required. Two of the advantages of such a barrier are the protection of the panel against peaking of roof load during pillar extraction and the easy closing of the entry in case of fire.

Jan 2, 1921

By L. G. E. Bignell, E. A. Hanson, J. O. Lewis

There was a general upward trend of all petroleum activities in Oklahoma during 1933, especially in the last quarter, though the average price for crude oil for the year was below 1932 and overproduction in East Texas demoralized conditions for several months. As the Federal Agencies established under the National Industry Recovery Act began to function conditions in Oklahoma were visibly affected and production of "hot oil" from Oklahoma City field practically ceased. More oil wells were completed, six new fields discovered, extensive geophysical prospecting carried on in many parts of the state, and an increased amount of clean-out and reconditioning work done in older pools during the past year. To increase quantity and rate of recovery of oil many wells producing from limestone formations were treated with hydrochloric acid. The Oklahoma City field had a reported production of 66,984,570 bbl. of oil during 1933, or almost exactly twice the amount reported for 1932. Potential tests and other indicators show that the wells are rapidly approaching the stage where mechanical lift must be applied to all of them, including the wells in the Wilcox sand zone. The major pipe-line companies serving the oil fields of Oklahoma have been anxious to make connections to all wells during 1933 and have indicated a willingness to accept all oil available. The amount offered has been restricted by proration orders, but the state did produce 178,356,-449 bbl. during the year, an increase of about 18.6 per cent over 1932. This increase was practically all due to the greater demand for Oklahoma City oil, as all other pools of any importance showed loss in production or very small gains last year. The U. S. Bureau of Mines' laboratory reports the lubricating distillate content of Oklahoma City crude from Arbuckle and Lower Simpson formations about 17 per cent by volume. East Texas oil is reported to contain about 5.6 per cent lubricating distillates. The desire of the transportation companies to keep their equipment operating at maximum capacity and the need of some refineries for more

Jan 1, 1934

F. E. BACHMAN, Port Henry, N. Y. (written discussion*).-Experi-ments with titaniferous ores found in Essex County, New York, made by the MacIntyre Iron Co. in 1914, showed' that titaniferous concentrates are reduced in the furnace with no greater, and probably with less, expenditure of heat, and consequently of fuel, than non-titaniferous mag-netites; and as a greater proportion of their oxygen is removed by carbon monoxide than is the case with non-titaniferous magnetites, a lower fuel consumption for the reduction of iron may be expected. After the furnace was blown out at the end of the experiment, the formation in the hearth was found to be abnormal. The brickwork was replaced, entirely around the furnace, by a layer which at -the tuyere circle was made up of cinder, fine carbon, and coke; the coke, however, gradually disappeared toward the bottom, being replaced by cinder and graphite. The usual salamander of graphite and iron was missing. The material left in the hearth seemed to be cinder that had not drained from the last cast; its composition, though, would indicate that it was in the furnace previous to the taking off of the titaniferous ore. At first, this material was thought to be blast-furnace cinder mixed with less iron and graphite than is normal; but an examination showed it to be made up of cinder with small masses of iron and graphite. There were also patches of a steel-gray material having a metallic luster; a microscope showed these patches to be made up of black metallic crystals interlacing white crystals.

Jan 11, 1919

By H. O. Hofman

Discussion of the paper of H. O. HOFMAN and JOHN BLATCHFORD, presented at the New York meeting, February, 1916, and printed in Bulletin No. 109, January, 1915, pp. 91 to 97. ROBERT H. RICHARDS, Boston, Mass.-I should like to ask Professor Hofman whether he is able to roast his stibnite without any comparatively large amount of loss of antimony? H. O. HOFMAN, Boston, Mass.-Yes. The last statement I made was that the loss of antimony, during those tests, increased with the temperature, and that up to 372° C. there was no loss whatever in antimony, also that it increased to 4:2I per cent. with 545° C., the highest temperature that we obtained in our small furnace. ROBERT H. RICHARDS.-I should like to ask a second question, and that is, is it not true that stibnite can be roasted more completely than any other sulphide?

Jan 5, 1916

By A. J. Phillips, C. H. Mathewson

BERYLLIUM, magnesium, zinc and cadmium, together with mercury, constitute a coherent sub-group of the periodic system and these metals, excepting mercury, have been studied in sufficient detail by the new X-ray diffraction methods to prove their common adherence to the hexagonal close-packed type of crystal structure with a progressive increase in axial ratio as we pass through the group from beryllium to cadmium. The first four columns of Table 1 summarize the data on crystal structure of these metals reported in the International Critical Tables.1 The last two columns are based on results obtained in the present investigation. [ ] Twinning has often been observed in zinc and cadmium. The general aspects of this twinning are abundantly illustrated by photomicrographs, diagrams, etc., in the papers by Romig, and Mathewson and Phillips reported to this Institute in 1927.2 A determination of the composition

Jan 1, 1928

Briefly, can you relate how you got into the minerals industry and some of your experiences as an executive, engineer, and administrator? Also would you tell ME about your affiliation with the Society of Mining Engineers of AIME? Roseburg, Ore., was where I was born and raised. It was, and still is a lumbering town; it couldn't have been any farther from mining. Upon graduation from high school, I turned 18 and, having already signed up with the Army Corps of Engineers, I was in the service eight days after my birthday. Four months later I was in New Guinea. As an amphibious engineer, I saw many of the Pacific and Philippine Islands, and ended up in Japan just a few days after the war was over. In later years, my work took me back to several of the places I had been during the war.

Jan 3, 1978

By Ralph M. Barnett, Albert K. Smith

During the last few years, a great deal of interest has been aroused in the use of more refined blasting techniques. It has been the effort of many mining companies to reduce powder cost, obtain better rock breakage, reduce drilling costs and provide safer working places. With the advent of new types of powder and such techniques as cushion blasting, line blasting, smoothwall or soundwall blasting, and presplitting or preshearing, these goals are approaching reality. Smoothwall blasting and presplitting have re- ceived much attention at the Climax Molybdenum Co., Climax, Colo., mine because of the large cost factor involved. An experimental program was begun in 1961, and during 1964 to the present has been used in many working areas. Some spectacular results have been achieved by the operating personnel in hard ground, but the most beneficial results have been in areas where the ground has been soft and highly fractured.

Jan 7, 1965

By Harrison Souder

THE object of this paper is to bring to. the notice of engineers a safety detonating fuse by the use of which misfires in blasting may be eliminated and safety in blasting operations promoted. This new detonator is a French invention and is known as Cordeau detonant or detonating fuse and is sold under the name of Cordeau-Bickford. It consists of a lead tube 5 to 6 mm. in diameter, filled with trinitro-toluene. While applicable to all classes of mining it will appeal especially to those who have to do with deep-hole blasting in open-cut clines or quarries, or any operations where a large number of holes are to be shot at one time. Since the introduction of the deep-hole blasting in the Cornwall iron mines, much trouble has been experienced from misfires and many experiments were made to determine the best and safest method of blasting. Before the introduction of the detonating fuse it was found that to insure the best results, two or more high-power electric exploders, not less than No. 6, with specially insulated conductors, should be placed in each hole; the holes wired in parallel, and for a large number of holes the current to be supplied by a live wire to the bus or lead wires at about the middle of the bench. The voltage in general use is 110 to 220, but as our material is a magnetic iron ore and the holes are generally damp, we found it advisable to reduce this to about 30 volts to prevent short circuits. A No. 7 or No. 8 special insulated detonator was adopted. But with the best of care and attention to the minutest detail, we were not able to eliminate occasional misfires and the consequent ever present danger of accidents.

Jan 10, 1914

By E. S. Fisher, L. C. R. Alfred

The elastic anisotropy factors, c4,/c6,, c3,/cll, and c12/cl,, for hcp metal crystals vary significantly among the dgferent unalloyed metals. Significant variations with temperature are also found. The effects of elastic anisotropy on the dislocation in an elastic continuum with hexagonal symmetry have been investigated by computing the elasticity factors for the self-energies of dislocations in fourteen different metals at various temperatures where the elastic moduli have been reported. For most of the metals the effects of the orientation of the Burgers vector, dislocation line, and glide plane are small and isotropic conditions can be assumed without significant error. Significant effects of anisotropy are, however, found in Cd, Zn, Co, Tl, Ti, and Zr. The elasticity factors have been applied in the calculations of dislocation line tensions, the repulsive forces between partial dislocations, and the Peierls-Nabarro dislocation widths. It is predicted that the increase in elastic anisotropy with temperature in titanium and zirconium makes edge dislocations with (a), (a + c), and (c) Burgers vectors unstable in basal, pyramidal, and prism planes, respectively. The probability of stacking faults forming by dissociation of Shockley partials in basal planes also decreases with increasing c4,/c6, ratio, when the stacking fault energy is greater than 50 ergs per sq cm. The widths of screw dislocations with b = (a) in titanium and zirconium increase very significantly in prism planes and decrease in basal planes as c4,/c6, increases. The effects of elastic anisotropy on various dislocation properties in cubic crystals have received considerable attention during the past few years. In the case of cubic symmetry the departure from isotropic elasticity depends entirely on the shear modulus ratio, A = 2c4,/(cl, —c12); i.e., the medium is elastically isotropic when A = 1. Foreman1 showed that an increase in the ratio A produces a systematic lowering of the dislocation self-energy for a given orientation and Poisson's ratio. ~eutonico~, has shown that large anisotropy can have a marked effect on the formation of stacking faults by the splitting of glissile dislocations in (111) planes of fcc and (112) planes of bcc crystals. ~iteK' made similar calculations for (110) planes of bcc metals. Both studies of bcc metals showed that the large A values encountered in the alkali metals tend to reduce the repulsive forces between Shockley partial dislocations. In fcc metals, however, A does not vary over the large range encountered in bcc metals; consequently, the effect of A on the forces between Shockley partials is masked somewhat by the differences in Poisson's ratio between metals. The effect of A on the line tension of a bowed out pinned dislocation has also been investigated for cubic crystals, first by dewit and Koehler5 and more recent- ly by Head.6 In both cases the line energy model is applied and the core energy is not taken into account, thus making the conclusions somewhat tenuous with regard to the physical interpretation. Nevertheless, the fact that a large A decreases the effective line tension is clearly evident and the tendency for large A to produce conditions that make a straight dislocation unstable (negative line tensions) also seem evident. Head, in fact, shows visual microscopic evidence that stable V-shaped dislocations occur in 0 brasse6 For hcp metals the definition of elastic anisotropy is more complex and, furthermore, significant deviations from an isotropic continuum are found among a number of real hcp metals, especially at higher temperatures. The present work was carried out to survey the effects of elastic anisotropy on the elasticity factors, K, that enter into the calculations of the stress fields around a dislocation core. Some isolated analytical calculations have previously been carried out for several hcp metals but they are restricted in the dislocation orientations and temperature.8'9 The present computations are based on single-crystal elastic moduli that have appeared in the literature and consider various orientations requiring numerical computations. The results are then applied to survey the effects of temperature on the dislocation line tension and dislocation splitting in hcp metals. PROCEDURE Anisotropy Factors. The degree of elastic anisotropy in hcp crystals cannot be described by a single parameter, such as the A ratio in cubic crystals. The following three ratios must be simultaneously equal to unity in order to have an elastically isotropic hexagonal crystal: The magnitudes of these ratios at several temperatures, as computed from the existing data for the elastic moduli of unalloyed hcp metals, are given in Table I. There are no cases of complete elastic isotropy, but the large anisotropy ratios encountered in the cubic alkali metals are also missing. There are, however, several significant differences among the hcp metals, the most notable being the relatively small A and B ratios in zinc and cadmium and the differences in the magnitudes and temperature dependences of A. It has been noted that the temperature dependence of A has a consistent relationship to the occurrence of the hcp — bcc tran~formation. For cadmium, zinc, magnesium, rhenium, and ruthenium, A is less than unity at 4'~ and, with exception for rhenium, decreases with increasing temperature. In the case of rhenium, A has essentially no temperature dependence between 923' and 1123"~, so that it is clear that A does not approach unity at higher temperatures. Cobalt is similar to the above-mentioned group of metals in that it also does

Jan 1, 1969

By N. A. Gokcen, J. Chipman

A revised treatment of the authors' published data eliminates the complex relation previously proposed between concentration of silicon and activity coefficient of oxygen in liquid iron. Revised values of the thermodynamic properties of the liquid solution are presented. IN a recent experimental study of the reaction SiO2 (s) = Si+ 2O; Kf, = [% Si] [% O]² [1] the authors' found a substantially constant equilibrium product in liquid iron at 1600°C of 2.8x10-5 They also reported extensive data on the reactions: SiO2 (s) + 2H2 (8) = Si- + 2H2O (g); K'2= [% Si] (H2O/H2 [2] and H, (g) + 0 = H2O (g); K'3 =( H2 O [31 (H2) [%O] From the results on reaction 3 and earlier data of Dastur² on this same reaction in the absence of silicon, they determined the activity coefficient of oxygen, f0, on the basis of the definition K3 = (H2O)/ (H2)f0 [% 0] where K, is the equilibrium constant and f0, is taken as unity in the pure Fe-0 system. Similarly values of fsi were deduced from results on reaction 2. In a more recent study" of analogous reactions in the system Fe-A1-0, it was found impossible to reconcile the results on reaction 3 with Dastur's data; accordingly the latter were ignored and the equilibrium results were extrapolated to find a value of K, at zero concentration of aluminum. This procedure failed to locate the cause of the discrepancy but it did yield reasonable values of activity coefficients. It also avoided introduction of the complex empirical relation between the oxygen activity coefficient and the concentration of the added element. The same type of discrepancy exists for system Fe-Si-0.' In the earlier paper an attempt was made to fit both sets of data by a single curved line (Fig. 6 of ref. l), the form of which is contrary to the theoretical requirement of a finite slope at infinite dilution. In the light of experience on the Fe-A1-0 system the discrepancy must be recognized as one which can be resolved only by more refined measurements. Accordingly Figs. 6 and 10 are retracted. It is pointed out also that until the discrepancy is resolved Figs. 7, 8, and 11 are subject to some uncertainty. Qualitatively the following conclusions still appear valid: 1—The activity coefficient of oxygen is reduced by addition of silicon. 2—In dilute solutions the activity coefficient of silicon increases with its concentration. 3—With respect to equilibrium in reaction 1, the above effects are approximately compensating. The discussion of K'1 in the previous paper requires no revision. It was pointed out that the constancy of the product [% Si] [% 0]² ndicated a compensating effect of the activity coefficients of silicon and oxygen. Therefore, as a very good approximation, K1 = K'1 and the following average values are suggested both for K, and K', at the temperatures 1550°, 1600°, and 1650", respectively, 1.0x10-", 2.8~10-" and 5.5 ~lo-'. Revision of the thermodynamic treatment is necessitated by the recent appearance of new data, based on a combination of combustion and solution calorimetry,' which yields for the heat of formation of low-cristobalite from the elements, the value —209,330 ±250 cal per mol at 25°C. This is about 4000 cal larger than the value previously accepted. The new value for cristobalite is used, together with Kelley's tables of high-temperature heat contents" and entropies and with Korber and Oelsen's' heat of fusion of silicon to obtain the following equation for the standard free energy of cristobalite in the temperature range 1700" to 2000°K: Si (1) + 02 (g) = Si02 (crist.); ?F° = -217,700 + 47.OT [4] The free energy of solution of 0, in liquid iron is:8 O2 (g) = 20 (in Fe); AF° = -55,860 - 1.14T [5] and these two equations are combined to give: Si (1) + 20 = SiO, (crist.); AF° = -161,840 + 48.14T [6] ?F°1873 = -71,700 cal. From the experimental value of K, = 2.8x10-5, Si + 20 = SiO2 (crist.); ?F°1873 = -39,000 cal. [7] The combination of Eqs. 6 and 7 yields the free energy change when liquid silicon dissolves in iron to form the dilute solution of unit activity (1 pct). Si (1) = Si; ?F°1873 = -32,700 cal. [8] The heat effect in this process according to Korber and Oelsen' is an evolution of 28,500 cal per gram

Jan 1, 1954

G. McMEANS*—This paper is a very good demonstration of the use of a new tool for the solution of industrial problems of a physical nature. To have solved this problem without the use of radioactive tracers would have required a far greater amount of investigation and work. The authors have described their work in such detail and in such a manner as to suggest the possibilities of the use of such tracer studies in the solution of many perplexing problems of industry. R. E. BREWER †—The authors are to be congratulated on this very excellent paper, which describes the results obtained by utilizing radioactive tracers in investigating the complicated reactions in the coking process. The paper has especial merit because the study was made under typical operating conditions in a commercial coke oven. Considering all the difficulties involved, the results obtained are excellent. My brief comments will relate primarily to the method used for determining the sulphur in the gas and to the value of the data obtained in stimulating further research. In discussing their results, the authors state (p. 17) that "Of the total sulphur charged to the oven in the coal 95 pct was accounted for in the coke and gas. Most of the sulphur unaccounted for is believed to have been lost in the gas, since the gas sampling system removed all the H2S but probably only part of the organic sulphur compounds present in the gas. Although sulphur in the acid-insoluble tar residue in the gas scrubbing bottles was determined and added to the total sulphur determination of each sample, it is doubtful whether an aliquot portion of tar for each sample was obtained." The reviewer believes that the authors might have obtained a better sulphur balance had they used an improved procedure for determining sulphur in the gas. The absorption train should have included a trap to remove the tar and am-moniacal liquor and a wash bottle containing 5 pct sulphuric acid to remove ammonia in the coke-oven gas before it entered the gas scrubbing bottles containing the ammoniacal cadmium chloride solution. Sulphur in the tar and

Jan 1, 1950

[Abstmct of remarks by R. II. Sweetser arid suhscqueut discussion at the New York Meeting, February, 1926. The Transactions mill ultimately contain a report of work resulting from these discussions. Need for a standard of ualuration.—There should be an accepted method for evaluating the different kinds of bituminous coals based on their carbon just as that for iron ores is based on iron. Variation in the classes of coals and their desirability fol the different industrial uses is analagous to the case of iron ores. The iron people have developed a standard. In the past coals have not been intelligently distributed because the public has not been informed as to its uses. Many operators have known nothing about the final disposal of the coal shipped from their mines. Sales agents and retailers have had no means of evaluating coals except to make the price as high as the market will stand. Producers and distributors need to know how much more valuable the coals would be if prepared so as to contain less objectionable material. Mr. Swectser cnlletl on the Goal and Coke Committee of the Institnte to organize a study through producers and users to develop a method scientifically and comnereially sound E. A holbrook said that the information exists but the public is unwilling to investigate. He praised Ashley's1 nomenclature of the different kind of coal which has been accepted by the Coal Mining Institute of America and recommended to the American Enginecring Standards Commitee. G. S. Rice pointed out the wider variety and distribution of consumption of coal compared to Iron ore. C'. M. Young approved Mr. Sweetser's remarks and hoped lor a research institution, probably endowed, to study utilization of coal after it comes from the ground. Mr. Sweetser cited incidents to prove his former statements. He said that a reduction of 1 per cent. ash in the coal would cut down the cost of pig iron at a blast furnace 30 c. a ton, that the coal men should tell what the iron men would have to pay to get better coal. H. J. Prryn endorsed the need of blast-furnace operators to know the kind of coal from which their- coke is made and the latler's ash content, as this affects coke consumption. A. C. Fieldncr explained that the difficulty of evaluating coal on the basis of chermical analyses for calorimetric tests is: (1) representativr

Jan 1, 1927

By E. C. Weichel

THERE have been many attempts at permanent roof support in anthracite mines, in some cases brick arches, in others concrete, and also combinations of brick or concrete walls with steel beams. These supposedly permanent roof supports have frequently failed when heavy pressure is brought to bear upon the structure, because they are so rigid that failure occurs because the structure is unable to adjust itself to the increased load. Roof pressure exerts a tremendous weight, and it is at times difficult to find any means of support which is strong enough to bear the entire pressure, unless this supporting structure has in itself the element of some flexibility which will enable the structure to hold the moving mass until it "arches" itself. If the supporting medium has flexibility enough so that it can adjust itself to the heavy initial loads, and so give the overlying material an opportunity to form a self-supporting arch, then such a roof support will be more useful than any rigid roof support. There has recently been introduced into the anthracite region a new form of gangway lining that is flexible enough to slightly adjust itself under heavy pressures, and so give the loosened material which is being supported a chance to form into an "arched" mass. This lining, manufactured under patents granted to Hans Schaefer of Essen, Germany, was introduced in the United States in the summer of 1928, at which time the Amercan licensee, Richard Howells of

Jan 1, 1930

By AIME AIME

CHARLES A. CHASE, manager of the Shenandoah-Dives Syndicate, operating the Shenandoah Mines in southwestern Colorado, reviewed the current work at that property at a recent meeting of the Colorado Section, in Denver. This operation is a new one, having been in effect only two years, but the properties that were consolidated by Mr. Chase had had certain production in earlier years, since when they had: been inactive. These properties are located. in the high mountains of the San Juan section in Colorado, and although they had had a substantial production of ores of good grade in the upper levels, the project as a whole involved the bold undertaking of driving through the mountain, starting on the Mayflower claim on the Arrastre Gulch side and passing through the Mayflower, Slide, Terrible, North Star, Dives and Shenandoah No. 3 claims. This is a distance of over 8,000 ft. which is known to be mineralized, and the main operating tunnel was started at an elevation of approximately 11,000 ft. The main exploration work has already extended in nearly 4,200 ft. and the present mining production of nearly 550 tons daily is being secured while the main exploration work is being continued. The main heading is now within the North Star claim and the plan of operations involves continuing ahead for a few hundred feet and then starting an upraise which will he 2,200 ft. high and which will connect with the old workings of the North Star mine. The plan of ruining then will he to drive levels along the vein in both, directions to daylight and retreat downward, taking out all the ore and abandoning, the workings after the ore is removed. In this way one level after another progressing downward will be abandoned. The raise will be of two compartments, one of which will carry the 8-ton skip and the other the counterweight and manway. So far the ore has been broken over an average width of more than 11 ft., with an output of 39 tons per machine shift.

Jan 1, 1932

By W. R. Hudspeth

AS an outgrowth of its spodumene recovery operation at Kings Mountain, N. C., Foote Mineral Co. has been recovering a heavy mineral by-product. Foote leased this idle plant in 1951, reactivated it, using a new spodumene recovery process, and purchased plant and properties in October 1951. While the operation at Kings Mountain is primarily concerned with the production of spodumene concentrate, pilot plant work determined that the pegmatites also contained heavy minerals including cassiterite. Plans were made to recover the heavy minerals as a by-product and the flowsheet incorporated these facilities when the mill was modified for the new spodumene recovery process. The orebodies consist of spodumene, feldspar, quartz and mica. Apatite, tourmaline, and beryl are present in small quantities. The wall rock is pre- dominantly hornblende shist. The heavy minerals, including cassiterite, columbite, pyrrhotite, monazite, pyrite, and rutile represent about 0.2 pct of the ore. The fine-grained heavy minerals are disseminated throughout the dikes, apparently unassociated with the spodumene. The pegmatites are quarried and secondary breakage is by mud-capping and block-holing. Power shovels load into trucks transporting the ore to a coarse ore bin. A Telesmith 10x36-in. apron feeder delivers the ore to an 18x36 in. Traylor Jaw crusher adjusted to discharge -3 in. product to a primary conveyor. The conveyor delivers to a 4x5-ft Tyrock single deck vibrating screen using 3/4 in. cloth. The screen undersize is elevated to the crushed ore bin. Screen oversize goes to an Allis-Chalmers Hydrocone Crusher fitted with 4 in. concave and set to deliver approximately 66 pct minus 3/4 in. The crusher discharge returns to the primary conveyor. The crushing and screening installation has a capacity of about 60 tons per hour. Spirals The crushed ore is delivered at a rate of 350 tons per day to two 6x8-ft Hardinge Pebble Mills, equipped with 20 mesh Ton-Cap trommel screens. The screen oversize is pumped to a 12-in. hydroclone for primary desliming. The hydroclone underfl spirals. There is no heavy mineral loss in the hydro-clone overflow. The spirals bank consists of eight 5-turn Model 24-A Humphreys Spirals. The top port and the last four ports of each spiral are blanked, the remaining nine port splitters are adjusted to remove about 5 pct feed weight. The heavy mineral rougher concentrates are upgraded on a Deister Overstrom table. The spiral concentrates contain approximately 4 pct heavy mineral, and the spiral reject, which goes to another section of the plant for spodumene recovery, contains about 0.03 pct heavy mineral. There is an interesting feature in the spirals installation. An adjustable splitter mounted on the discharge boxes splits out a mica fines product containing very little heavy mineral. The mica product is cleaned by spiralling and screening. Thus the spirals recover two products; mica, and a heavy mineral rougher concentrate. Table Treatment The rougher spiral concentrate goes to a Deister Plato table, modified to receive a Deister-Overstrom No. 6 rubber cover with sand riffles. The table is operated with a 5/8 in. stroke, 270 strokes per minute, and a slope of 1/2 in. per ft from feed to tailings side. There is no slope adjustment from motion to concentrate end. Wash water consumption is relatively high, since the large spodumene grains tend to report with the fine heavy minerals. A middling band about 4 in. wide is maintained in order to produce clean concentrate. The middling, representing about 10 pct of table feed, is recirculated by air-lift. A band of concentrate grade coarse spodumene occurs just below the middling. This is removed and delivered to concentrate storage. The table tailing, containing approximately 0.7 pct heavy minerals, is returned to the spodumene feed preparation circuit. The heavy mineral table concentrates are approximately 45 pct cassiterite, 33 pct columbite, 14 pct pyrrhotite and 8 pct monazite, together, with some rutile, pyrite, and copper from blasting wire. Concentrate is collected at 24 hour intervals. and dried. If the concentrate remains in wet storage appreciably longer surface oxidation takes place which seriously interferes with the subsequent magnetic separation process. About 150 lb of heavy mineral concentrate is produced per 24 hours and shipped to the company's plant at Exton, Pa. for final separation into tin and columbium concentrates.

Jan 1, 1952