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By G. K. Engelhart

EFFECTIVE use of rotary kiln waste gases to preheat dry pulverized materials has been demonstrated in full-scale operation at the Allentown Portland Cement Co. plant, Evansville, Pa. Pulverized raw materials are preheated in suspension in the gas stream in a multi-stage counterflow process which draws the gases through a series of cyclone collectors. Upon entering the first cyclone stage the material, continuously delivered and suspended in the gas stream, is successively collected and resuspended until it discharges through the kiln feed pipe. Gas and material contact time is thus prolonged, providing a high degree of heat recuperation with a very low temperature differential between gas and material at the final stage. The suspension preheater, developed by Klockner-Humboldt-Deutz AG of Cologne, Germany, was first installed at the Norddeutsche Huette plant, Oslebshausen, Germany. Similar preheaters are now in operation at three other German cement plants. The first American installation, at the Allentown Portland Cement Co. plant, was designed and manufactured by Fuller Co. of Catasauqua, Pa., Humboldt's licensee for the United States, Canada, and Mexico.

Jan 4, 1954

By E. Nelson Fell

As this plant is the first ever erected in British Columbia for the treatment of tailings by the cyanide process, and as the ores of this, mine are of a character not unusual among gold-ores of this Province, it is probable that a description of the principal features of the plant, and of the methods employcd in its operation, may be interesting. These works were designed after a careful study of the process, in a small experimental plant, for a period of six months. During this period ten percolation-tests on charges of tailings of 1100 lbs. each, eight percolation-tests on similar charges of concentrates, and twenty-six tests 011 concentrates in a revolving barrel, were made, besides laboratory-experiments. The ore consists of a quartz gangue, containing a little lime and variable quantities of the sulphidcs of iron, lead and zinc. The following figures, giving the analyses of the ore before milling, and of the tailings after milling, which constituted the material to be cyanided, are based on the daily samples taken during February and March, 1901.

Jan 1, 1902

By H. L. Riley, B. W. Gandrud

As far as the present writers know, this system of flotation has not been used elsewhere in this country, but in the last couple of years it has been introduced, with minor variations, at one plant in England and one in Wales. The system has been described and discussed in a number of publications. The following is quoted from an abstract of the latest of these," a paper presented at an International Conference on Industrial Combustion in 1952. On the basis of experience to date with the commercial plants, it is believed that the kerosene-flotation process incorporates all the necessary elements to make it greatly superior to anything else now available for treating of fines in wet processes of coal preparation. Additional study and investigation are still needed, however, to determine if certain phases of the process can be improved to such an extent as to make it generally satisfactory and acceptable to the industry. Further improvements will be needed with respect to the capacities of the flotation cells and the reagent consumption.

Nov 1, 1955

By R. R. Nash, W. F. Sheely

Experiments were conducted on magnesium monocrystals in order to collect quantitative information on the mechanisms which limit the rate of basal slip. Using critical shear stress and creep data, activation energies for creep at low aid at high temperatures were derived. The activation energy at low temperatures is the same as that for jog formation and the activation energy at high temperatures agrees with that for climb. COTTRELL has suggested that at low temperatures, the expansion of dislocation loops under stresses near the yield strength is limited by the rate at____ which the expanding loops can cut the "forest" of dislocations passing through the glide planes.' On the basis of this mechanism, seeger2 has derived expressions for low-temperature creep and for the relation of flow stress of single crystals to temperature. In the work reported here, the authors have performed experiments designed to obtain quantitative data on the physical properties of the dislocation intersection mechanisms operating during basal slip in pure magnesium monocrystals. Above a critical temperature, dislocations thread-

Jan 1, 1961

By Vincent Carlsson

A comprehensive investigation has been undertaken to clarify how pellets are affected by alkali circulating in the blast furnace. The investigation has been performed with acid and basic pellets in a special furnace. Experiments were carried out to ascertain the influence of potassium on swelling and reducibility when added at different stages of reduction. After that, the significance of the quantity of potassium added in the hematite stage was studied. A parallel experiment with sodium as the alkali component was also con- ducted. Besides these vaporization experiments the effect of alkali on softening and reduction characteristics at high temperatures was investigated. The results showed that alkali always increases swelling, especially when added in the hematite stage. The addition of alkali increases reducibility of acid pellets during reduction from wustite to 70 % reduction. The softening temperature is significantly lowered by the addition of alkali and is, in any case, lower for acid pellets than for basic pellets. The microscopic studies showed that alkali ferrites can be formed irrespective of the influence of alkali on the slag phase.

Jan 1, 1977

By Joseph L. Gillson

YOUR speaker has long sought an opportunity to review the many differences between the subject matter called economic geology and the duties of a practicing economic geologist. As the subject was taught in my student days, professors teaching courses in economic geology paid little attention to what we now call industrial minerals. Certainly they were not concerned with problems involving production and marketing, but only with the origin of such mineral deposits as the Stassfurt potash deposits; with other evaporites, such as salt, gypsum, and Chilean nitrate; with the possible modes of formation of sulfur in salt domes; and the causes of asbestiform mineralization. Of course, much time and thought was given to the mineral identification and sequence of deposition of the minerals in pegmatites. The fact that such deposits actually produced commercial feldspar, mica, beryl, and lithium minerals for sale in industry was of minor importance. These observations lead us to pause to inquire, perhaps facetiously, what is and what is not to be included in the science of economic geology?

Jan 5, 1957

By W. H. W. Husband

Rock salt has been solution mined for many years in many countries. Attempts have been made in the past in Canada and various other countries to produce potash by the same method. However, only Kalium Chemicals Ltd. has been successful, possibly because the conditions in Saskatchewan are the most favorable to be found so far for the development of a solution-mining method for potash. In view of the fact that few studies of solution mining of potash have been attempted, only one company has succeeded in using the method, and no information has been released by this company, the application of solution mining of potash ore bodies has to be presented on the basis of available theory, past small-scale studies, and recent patents. A simple mining method is outlined and possible methods of recovering the potash from the brine are discussed. Dissolution data pertaining to solution mining of potash, flowsheets, and material balances are presented. The available information is brought together in a cost analysis to show capital and product costs in terms of 1966 dollars.

Jan 1, 1972

By H. W. Gudenau, R. S. Chatty, W. Wenzel, M. Ponthenkandath

During several experimental programs conducted at the Institute of Ferrous Metallurgy, Technical University, Aachen, whisker formation was observed when iron ores were reduced at low as well as at high temperatures. Thus, in an attempt to find the reason for the volume change taking place during reduction, iron whisker growth was observed. Whisker growth appears to be one of the important reasons for the swelling of pellets. One set of experimental observations determined that when iron forms as needles rather than as a crust on the surface of oxide, the pellets became very porous. In related experiments, the beneficiation of finely disseminated iron ores, in which the metallic iron is separated from the gangue in granular or nodular form, was achieved by a reduction-concentration method. In this process, which is conducted at sufficiently high temperatures, oxide whisker growth, resulting from the formation of volatile suboxides and a gas transport mechanism, plays a vital role in the joint deposition of SiO, and iron from the vapor stage.

Jan 1, 1973

By H. L. Luo, W. Klement

By rapidly quenching Ag-Pt alloys from the melt, a continuous series of solid solutions has been obtained. At equilibrium''2 these fcc elements form a peritectic system, Fig. 1. Weighed amounts of silver and platinum powder (325 mesh, purity greater than 99.9 pct) were mixed for 24 to 120 hr, pressed into compacts, sintered at 1000°C in a hydrogen atmosphere for at least 16 hr, and then furnace-cooled. Because of the difficulty in achieving homogeneity in alloys containing more than about 40 at. pct Pt, the sintered compacts were induction-melted under hydrogen in alumina crucibles and then cold-rolled into wires. Small amounts ("30 mg) of alloys cut from various sections of the sintered compacts or rolled wires were heated to at least 50' ~ above the liquidus in an alumina insert held within an induction-heated graphite crucible; then the molten alloy was ejected by a blast of helium onto a lightly polished copper strip held on the inner periphery of a rotating wheel. The flakes thus obtained were typically 1 sq mm in area or often slightly larger for the silver-rich alloys. X-ray diffraction patterns were obtained with nickel-filtered copper K radiation in a 114.6-mm-diam Debye-Scherrer camera with rotated specimens. Lattice parameters and associated uncertainties were estimated from extrapolations against the Nelson-Riley function. High-angle lines were always resolved and spacings were computed relative to r(CuKa!,) = 1.540508 The details of these techniques have been discussed previously.s'6 Lattice parameters of the solid solutions are plotted in Fig. 2, together with the data of Schneider and Esch,' Johansson and Linde,' and Novikova and pudnitskii. Each of the present lattice spacings represents two or more independent determinations. The alloys were homogeneous within 2 at. pct of nominal composition as estimated from the uncertainties in the lattice spacings. Many of the mechanisms involved in the achievement of metastable solid solutions by rapidly quenching from the melt have been previously discussed. There is some evidence" that such solid solubility cannot be obtained when the liquid alloys are cooled

Jan 1, 1963

By D. R. Hay, E. Scala

STUDIES of structure-sensitive properties, especially mechanical behavior, have shown that grain and subgrain structure play an important role. The mechanical properties of tungsten, in particular, are sensitive to the nature of the intergranular structure. Substructure and dislocation networks in single-crystal and polycrystalline tungsten have been studied by Nakayama et al.' Various orders of substructure were observed ranging from a microscopic first order (grain diameter: 2 to 8 mm) to a microscopic second order (grain diameter: 50 to 300 p), and, within the latter, dislocation networks forming an even smaller order of substructure. In their single crystals, grown by arc fusion, the degree of misorientation in each order was small: 16'3OU, -11, and -10" for the first-, second-, and third-order substructure, respectively. To study the properties of polycrystalline tungsten, powder metallurgy tungsten is generally used. However, in a mechanical property investigation, the zone-melted or arc-fusion crystals are more desirable than the powder metallurgy product due to their higher purity and absence of porosity and other defects inherent in consolidation by powder metallurgy. Grain boundaries can also be produced in melted stock by working and recrystallizing. However, material with subgrain mis orientations of the order of several degrees (high-angle substructure) has not been reported previously and is the subject of this communication. Crystals were grown by electron-beam, floating-zone melting. The starting material, Sylvania Pure-tung welding rod, was given one zone pass at a traversal rate of -2 mm per min. Through control of the zone temperature, it was possible to influence the degree of crystal perfection. By maintaining the zone at a high degree of superheat, high-perfection crystals could be grown. However, at temperatures only slightly above the melting point, the zone-melted crystals contained a high-angle substructure. A sensitive control of the zone temperature was not possible due to the difficulty of estimating the temperature of the zone and of providing a constant supply of power to the sample. Therefore, an empirical method, using the shape of the molten zone as a criterion, was adopted as an indication of temperature. At high degrees of superheat, the surface tension of the molten zone decreases and a neck forms at the top of the zone, whereas at low zone temperatures the diameter of the zone remains reasonably uniform. Although it was not possible to obtain a continuous variation of misfit angle, the conditions could be directed toward the growth of either high- or low-angle substructure by maintaining only a slight neck in the zone (sufficient to establish that it was molten) or a well-necked zone, respectively. Mass spectrographic analyses of both types of material revealed no significant differences in the concentrations of their impurities. The degree of misorientation at high angles was obtained by measuring the angular spread of spots corresponding to a single reflection on a Laue back-reflection photograph. Fig. 1 shows a typical Laue back-reflection photograph of a crystal with a 3-deg spread. By measuring the angular deviation of the spots corresponding to a single reflection from the mean center of the spots around which constant angular deviation contours were drawn, an average angular spread of misfit could be calculated. The angular average was weighted by the number of spots observed in each angular interval. At angles greater than 5 to 6 deg the spots from different reflections begin to overlap, and cannot be associated with a particular reflection. Laue back-reflection photographs taken at different locations on samples .with approximately 3-deg spreads showed only a small difference in angular misorientation, less than 8' of arc, within individual specimens. The microstructure was examined using Berg-Barrett X-ray extinction contrast microscopy. Berg-Barrett photographs taken directly on the as-grown surface, Fig. 2, show an essentially equiaxed subgrain structure of -0.1 mm in average grain diameter in both high- and low-angle crystals. Fig. 2(a) is a photograph of a sample with a low misfit angle and Fig.

Jan 1, 1968

By E. T. Hayes, A. H. Roberson, M. H. Davies

ZIRCONIUM has been produced on a pilot-plant scale for only a few years, but the potential uses have led a large number of research establishments to engage in a thorough study of the metal and its alloys. The work described in this paper is part of a cooperative project between the Bureau of Mines and the Air Materiel Command. The Zr-Cr system was one of the first investigated because of the possibilities of improving the properties at elevated temperatures, the chemical corrosion resistance, and the mechanical properties of zirconium in a manner similar to the enhancement of the properties of titanium by additions of chromium. There is no published work on the Zr-Cr system but from the similarity of the metals involved it was expected that it would be similar to the Zr-Fe' and Ti-Cr' systems. The materials used in this investigation were prepared in the Bureau of Mines laboratory at Albany, Ore. Zirconium was produced by magnesium reduction of zirconium tetrachloride, and a typical analysis is as follows: Fe, 0.06 pct; Ox, 0.08; N?, 0.01; C, 0.02; and other impurities such as Al, Pb, Ni, Ti, and Si less than 0.01 pct each. High purity chromium was prepared by treating crushed electrolytic chromium in a stream of dried and purified hydrogen." The resulting powder contained about 0.01 pct 0 and about 0.1 pct total metallic impurities. All alloys were prepared by arc-melting 50 g briquetted compacts of the desired composition in a Kroll-type" arc furnace using an inert atmosphere. The furnace was evacuated twice and backfilled with helium, which was gettered by melting a center zirconium button immediately before the alloys were melted. Alloys were remelted at least once to insure greater uniformity of composition and subsequently were annealed in vacuum at 1250°C for 48 hr. Fairly homogeneous alloys were obtained by this means; a slight loss of chromium from the surface by evaporation during the high temperature homogenization was noted. All alloys were analyzed for chromium and gave results in good agreement with the nominal composition. Spot checks on tungsten and nitrogen showed pick-up of these elements to be negligible. Over 70 alloys were prepared for use in this investigation; only the critical ones are shown in Table I. Alloys containing up to 10 pct Cr were amenable to hot working at 850°C and a number of these were sheath rolled to 1/16 in. thickness. Specimens were cut from the sheet for use as metallographic samples. For the thermal analysis a differential couple was used in conjunction with an X-Y recorder, the temperature of the specimen and the difference in ternperature between it and the standard nickel body were recorded simultaneously. Heating and cooling rates of 5°C per min were used. The sensitivity of the instrument was such that a difference in temperature between the specimen and standard equivalent to 0.1 mv produced a deflection of 1 in. on the recording chart. The chromel-alumel thermocouples were checked against a Bureau of Standards calibrated thermocouple. Melting-point determinations were made in a high vacuum induction furnace using an optical pyrometer. The pyrometer, calibrated against nickel, copper, and zirconium (iodide process) under near black body conditions, was focused on the base of a hole drilled in cylindrical samples. A North American Philips Geiger counter X-ray spectrometer was used for all diffraction studies. This instrument, in addition to supplying precise intensity measurements of planar reflections, has an added advantage in that metallographic specimens mounted in bakelite can be used directly, and this

Jan 1, 1953

Discussion * of the paper of H. M. Chance, presented at the butte meeting, august, 1913, and printed in bulletin No. 79, July, 1913, pp. 1315 to 1341. George H. Ashley,+ Washington, d. C.:-Mr. Chance's long practical experience in reporting on coal lands admirably fits him for a discussion of the value of such lands. On behalf of the government geologists, I wish to express my appreciation of Mr. Chance's friendly, constructive criticism of the government method of valuing coal land in the first part of his paper and, at the same time, to reply to some queries he makes. All admit that coal has no " intrinsic "-monetary value, in the sense that a pound of coal of certain chemical and physical characters is worth " intrinsically " so many cents or fractions of a cent. The term has, however, been found very useful as including those natural factors of coal value, among which are its position and location in the earth, that affect its sale price in contrast with the other cost elements involved in the labor and capital necessary in mining, preparing, transporting, and selling the coal (extrinsic factors). Mr. Chance, while recognizing the " dual origin of value," does not offer any better terms. The survey agrees with Mr. Chance in his definition of coal conservation, that it means the fuller utilization of the heat contents of the coal, and the more complete recovery of the coal from the ground. Coal land withdrawals have not been made to keep such lands off the market, but to prevent their acquisition as non-coal lands before they could be classified so as to be disposed of under the proper law. Nor has the pricing of the more valuable coal lands above the minimum been to raise money for the reclamation fund, to which the money goes, but primarily to discourage the alienation, for holding or speculation, of coal lands not intended or needed for development, and, secondarily, to secure to the people the ?unearned increment," which they are certain in any case to be charged.

Jan 11, 1913

By George S. Rice

THE A.I.M.E. Ground Movement and Subsidence Committee, pro- posed in 1920, held its first technical meeting in February 1923, under the able chairmanship of Mr. H. G. Moulton. The following list of papers and discussions, indicating the scope of the problems and relation to various conditions and method of mining, were given at that meeting by the distinguished mining engineers: J. Parke Channing, on Subsidence at Miami, Arizona; Howard N. Eavenson, on Mining an Upper Bituminous Seam after a Lower Seam Has Been Extracted; J. J. Rutledge, on Subsidence in Two Oklahoma Coal Mines; Benjamin F. Tillson, on Caving Cracks at the Franklin Mine, New Jersey; Dr. F. W. McNair, on the Dome Theory; William Kelly, on disadvantageous effects in Mining and Back-filling Working Upward a Steep-Pitching Iron-ore Bed; Eli T. Conner, on the good results of Back-Filling by Hydraulic Means in Preventing Destructive Subsidence in the Anthracite District; Thomas H. Claggett, on the merit of Systematic Pillar Drawing in Preventing Cracks in an Upper Seam; Henry H. Otto, successful results in the anthracite district in Mining Lower Seams before Upper Seams; Douglas Bunting, on Leading Factors Incident to Successful Mining of an Overlying Seam; Edwin Ludlow, on there being "less damage to buildings when there was complete removal of coal with complete packing than when room and pillar is used without extracting the pillars"; Edward O'Toole on "bumps" in eastern Kentucky mines, which he thought were the result of geologic stresses: H. A. Buehler, on Upheaval of Surface in an Illinois Case in Advance of the Face; and R. Dawson Hall, on The Mechanics of Subsidence from Mining. The author of this paper discussed various kinds of problems of ground movement and subsidence in both metal mining and coal mining; the production of great landslides by workings near an outcrop, as at Turtle Mountain, Alberta, Canada; and general

Jan 1, 1939

By Thomas T. Read

The purpose of the following research, as originally planned, was to investigate the influence of temperature upon the plate-amalgamation process. In order to consider the amalgamation process intelligently, it was first necessary to learn the nature of an amalgam. In the performance of this task it was found necessary to consult a large volume of literature and to perform experimental investigations. The conceptions of the nature of amalgams thus obtained have so important a bearing on the amalgamation-process as a whole, as well as upon the possible influences of temperature, that it was advisable to include them in the treatment of the subject. The broader title is therefore used, even though some features of the amalgamation process have been treated very briefly and others entirely omitted, there being nothing new to present regarding them and their development not required for a clear presentation of the matter in hand. I. Historical Introduction. Gold was one of the earliest metals known to man. Occurring in the metallic state, it could be picked up in nuggets or mashed, as gold dust, from the sand and gravel of streams. Interestiag descriptions of the processes employed in early times for the recovery of gold may be found in Pliny's Natural History and in the treatise by Agricola on ores and minerals. But little progress in the treatment of the ores of gold mas possible until efficient crushing machines were devised. This want was supplied by the introduction, about the beginning of the sixteenth century, of the stamp-mill to treat the ores of Saxony. Blanket-strakes, or similar devices, were used to catch the

Jan 1, 1907

By Jed H. Mosgrove

One of the most interesting of all the subjects required of persons studying the different facets of coal mining is coal mine gases. Some mine gases have been a real problem since the very beginning of underground mining, and in the early days there was insufficient knowledge to cope with them. The history of mining shows that until about the last 50 years, much work was done primarily by the hand methods which are primitive by today's standards. Miners had to contend with gases without the aid of enclosed lighting, permissible mine machinery, sophisticated testing devices, and high-pressure ventilating fans. In early days the miners were not educated about the different mine gases nor did they have the technical equipment to determine the actual composition of the deadly atmospheres they encountered. They simply applied a descriptive term to each gas or mixture of gases depending on its, effect on a person or the surrounding atmosphere. The gases or mixtures of gases were then referred to as "damps," a term which was probably derived from the German word "damps," meaning vapors or gases. The more common damps encountered were : Blackdamp A condition of the atmosphere in which a miner's light would be extinguished and in which breathing would be difficult, sometimes even resulting in suffocation. An atmosphere deficient in oxygen which could contain a combination of any of the mine gases. Firedamp A flammable mixture of methane and air which would either burn or explode when ignited. White Damp A mixture of gases containing carbon monoxide, most often found in mines during fires or after explosions.

Jan 1, 1981

By R. P. Abendroth

The hydrogen-water vapor ratio at which Fe-Cr alloy, chromium oxide, andiron chromite coexist in equilibrium was determined between 900" and 1200°C. A thermogravimetric method was used to determine equilibrium conditions. The results fit a straight-line relationship in the temperature region studied, and are given by Reduction experiments were also performed to confirm the results of the equilibrium investigation. ThE oxygen pressures at which Fe-Cr alloy, chromium oxide, and iron chromite coexist in equilibrium have been previously determined by Boericke and angert,' Morozov and Novokharski,' and Katsura and uan. Only one determination (at 1300°C) was made by Katsura and Muan, but it agrees with the results of orozov and Novokharski. The results of Boericke and Bangert, however, differ appreciably from the results of these investigators. Previous studies have assumed that the equilibrium metallic phase is pure iron, but Dahl and Van vlack have shown that the iron contains from about 1 wt pct Cr at 1000°C to over 2 wt pct above 1300°C. The chromium oxide also contains a small amount of iron in solid solution. In the present study, hydrogen-water vapor mixtures were equilibrated with the condensed phases, using a therrnogravimetric method to determine equilibrium conditions. The reaction can be written EXPERIMENTAL General Procedure. The starting material was a sintered pellet of Fe2O3-Cr2O3 solid solution with a hole in the center, and was placed on a fused silica hook. This assembly was raised into the preheated hot zone of the furnace in a helium atmosphere, hooked onto a fused silica hangdown suspended from one arm of an Ainsworth Model RV-AU-1 recording balance, and the starting weight determined. A flowing hydrogen-water vapor atmosphere was then exchanged for the helium by evacuation, and the sample reduced until the weight loss indicated the sample composition to be in the alloy-Cr2O3-chromite field. The tem- perature was adjusted incrementally until constant sample weight was achieved for several hours, to within 0.02 mg. A hydrogen-water vapor atmosphere of different composition was then admitted, and the same procedure carried out. At the end of a series of determinations, the sample was examined by X-ray diffraction to verify the presence of the desired phases. Microscopic examination of the silica hook showed no interaction with the sample, nor did it lose any weight. Several criteria were used to insure equilibrium besides constancy of weight. For a given hydrogen-water vapor composition, equilibrium was approached from both oxidizing and reducing sides by varying the furnace temperature slightly. The resulting slow weight loss or gain was observed for several hours. Constant weight could be re-established by returning to the original furnace temperature. The last criterion used was varying the relative amounts of the phases by further reduction or oxidation, and observing any changes in temperature required for constant weight for a given hydrogen-water vapor atmosphere. None were observed. This procedure was essentially the same as approaching the equilibrium from oxidizing and reducing sides, but larger weight excursions were carried out. Sample Preparation. Reagent-grade Fe2O3 and Cr83 powders were mixed in the desired proportions and heated in air at 1250°C for 2 hr. The mixture was re-ground and heated in air overnight at 1250°C. X-ray diffraction showed complete solid-solution formation as a result of this procedure. The solid solution was then pressed into l/2-in.-diam pellets using Carbowax 4000 as a binder. The hole was drilled in the center, and the pellets were sintered 24 hr at 1250°C in air on a bed of Fe2O3-Cr2O3 of the same composition, contained in an alundum boat. After cooling, the pellet surfaces were abraded with 310 paper to remove any surface compositional differences, such as loss of Cr2O3. Chemical analysis of the sintered pellets was 67.16 wt pct CrP3 and 33.02 wt pct Fe203. Atmosphere Generation and Control. The hydrogen-water vapor atmospheres were generated by passing Matheson ultrahigh-purity hydrogen, with no further purification, through two water bubblers contained in a constant-temperature water bath. Since the water-vapor dew points required in this study were below room temperature, the bath was insulated, and was cooled by thermoelectric-immersion devices. The bath temperature was controlled to 0.0l0C. Since rather high flow rates of about 900 ml per min were used through the furnace tube, an independent check of the dew point was made to insure saturation of the hydrogen by the water vapor. Although the dew point could only be determined to within 1/2"C, the determined dew points agreed with the water-bath temper-

Jan 1, 1967

By Edwin Ludlow

THERE has been so much misinformation sent out through the newspapers, and I find so few people who are really acquainted with the true facts in regard to the coal strike, that I feel it would be advan-tageous to present the facts as I have been able to gather them. One of the great points that the miners are now mak-ing is the fact that the operators of the central competi-tive field, consisting of the states of Illinois, Indiana, Ohio and Pennsylvania, have refused to meet them in a joint conference such as has been customary in previous years. There are two reasons why the operators de-clined to hold such a meeting. In the first place, the last time they held a meeting of this kind they were all indicted under the Sherman Act for making an agree-ment in restraint of trade. In the second place, the miners at their convention did not authorize their dele-gates to negotiate a new contract, but instructed them that nothing less than a scale based on the present wage, with the addition that there should be a six-hour day, a five-clay week, time j and a half for over time, and double time for Sundays, would be accepted. These additions would very much increase the cost of coal over the present wage scale. The operators could not consider renewing a contract on the present scale, as it would mean ruin for them, and as the miners were not authorized to negotiate a new scale on a fair basis that would enable the operators to mine coal in competi¬tion, with the open-shop mines the operators did not feel that there was any use in meeting the delegates. Thirty per cent. of the output of bituminous coal comes from the open-shop mines of West Virginia, Alabama and Pennsylvania. During the strike, in 1919, this 30 per cent. was increased to 50 per cent. and it has affected the operations of the union mines to such an extent this year that they have been able to run only 15 to 30 per cent. of their time, while the open shop mines have run from 60 to 80 per cent. as the wages in these mines had been reduced to the 1917 scale.

Jan 5, 1922

By J. L. Bray, S. T. Ross

The paper provides electrometallurgical data on the problem of germanium removal from zinc sulphate solutions. Germanium traces have caused much concern to the zinc refiner. Confirmatory evidence of interaction between germanium and cadmium is presented. Statistical analysis of data expands its significance and enhances its value. Further research is outlined. THE literature contains many references to the effects of trace amounts of germanium in the production of electrolytic zinc. One of the authors had experience with this troublesome element as early as 1917 at Trail, B. C. In 1929, Tainton and Clayton' reported that concentrations of as little as one part per million of germanium were sufficient to cause serious losses in current efficiency. Liddell2 reported that trace amounts of germanium cause marked lowering of the hydrogen overvoltage of electrolytic zinc cells, so that commercial production was impaired. Bray3 recorded the history of germanium in relation to electrolytic zinc production, noting that concentrations below 10 ppm have been found to yield low current efficiencies and copious hydrogen evolution. Koehler' stated that germanium "when present to the extent of a small fraction of one part per million per liter, causes serious evolution of hydrogen with a corresponding reduction in current efficiency." Recently, however, S. W. Ross" reported, from Risdon, Tasmania, that "in the course of leaching . .. dissolved traces of germanium... if not removed almost completely ... increase the reversion of cadmium during the filtration of the copper-cadmium precipitate and reduce the current efficiency during subsequent analysis." The copper-cadmium precipitate referred to is the residue from the zinc-dusting purification of zinc sulphate leach solutions. In the face of such conflicting testimony and with the increasing industrial importance of pure germanium and zinc it was decided to investigate the relationship between cadmium and germanium. Furthermore, other work by the authors showed certain discrepancies to exist in the theories of Tainton, et al. In the laboratory, without marked efficiency decreases, the authors have deposited zinc successfully from solutions containing as high as 1 g per liter of germanium. This could be done only when there was no cadmium present. Preliminary investigations of the suspected rela- tionships were carried out by means of emission spectrographic analysis using a beryllium internal standard. Several solutions containing 100 g per liter of zinc, as zinc sulphate, and 1 g per liter of cadmium, as cadmium chloride, were prepared. These concentrations were on the order of those obtained during a commercial low-acid leaching process. Varying concentrations of germanium were added to these solutions so that the range of 0.0000 to 0.5000 g per liter of germanium was covered. A 250 ml sample of each solution was agitated with 2.5 g of zinc dust for 30 min, filtered, and the filtrates were examined spectroscopically. Qualitative evidences of cadmium traces were found in those filtrates which originally contained above 10 ppm of germanium. Reliability of the analytical method did not permit quantitative investigations since cad-Table I. Current Efficiencies Obtained at 0.0000 and 1.5000 G per Liter Cadmium Concentrations Ge Concentrastion,* Cd Concentration,* EtBclenoy, G per Liter G per Llter Pot 0.0000 0.0000 84.270 0.0010 0.0000 94.849 0.0050 0.0000 92.649 0.0075 0.0000 94.039 0.0100 0.0000 96.084 0.0000 1.5000 93.460 0.0010 1.5000 95.158 0.0050 1.5000 92.148 0.0075 1.5000 91.260 0.0100 1.5000 84.546 • Cd and Ge concentrations shown are those existing before zinc-dust purification. mium determination in the concentrations present in zinc-dusted solutions lacks sufficient sensitivity for reproducible results. As a consequence of the inability of the investigators to obtain acceptable results through direct quantitative analysis, an indirect approach was devised. This indirect method involved a study of the current efficiency, in a model zinc cell, as a function of the concentrations of cadmium and germanium. Variables such as cell temperature, voltage, current density, anode spacing, relative electrode area, degree of agitation, cathode preparation technique, time, acid concentration, and solution volume were held constant. Fig. 1 shows the cell used. The current was fur-

Jan 1, 1952

By Rossiter W. Raymond

(Read at the Amenia Meeting, October, 1877.) IN the case of The Eureka Consolidated Mining Company v. The Richmond Mining Company of Nevada, recently tried at San Francisco, California, the real defendant was the Richmond Consolidated Mining Company, of London; but this being a foreign corporation, holds its mining property in Nevada through the Nevada corporation of similar name, in which the London Company owns all the stock, except the few shares necessary to "qualify" the American directors. The trial would naturally have taken place in the Circuit Court at Carson City, Nevada, and before a jury. But by stipulation of the parties, the case was tried in San Francisco, before Hon. Stephen J. Field, Justice of the Supreme Court of the United States, Hon. Lorenzo Sawyer, United States Circuit Judge of the Ninth Circuit, and Hon. E. W. Hillyer, United States District Judge, for the District of Nevada. The hearing began July 23d, 1877. The witnesses occupied two weeks, and the argument of. counsel three days. Very eminent lawyers were. engaged on both sides ; for the plaintiff, Messrs. Solomon Heydenfeldt, R. S. Mesick, John Garber, and H. J. Thornton ; for the defendant, Messrs. S. M. Wilson, Thomas Wren, and J. J. Williams. The court held the case under advisement until August 22d, when Mr. Justice Field delivered its unanimous opinion in favor of the plaintiff. The action was a complaint in ejectment, and an appeal was taken to the United States Supreme Court. The questions at issue between the Eureka and the Richmond Company in this suit, comprised several points in the construction of the mining law of the United States, and its relation to the customs and regulations of the mining districts, which possess an importance and an applicability far beyond the limits of the case in which they arose. It is my purpose to state these points, the arguments

Jan 1, 1878

By E. L. Ickes

DURing the summer and winter of 1918 eleven standard rigs were erected in the United Kingdom to test the petroleum prospects of- ten structures, eight of which were in England and two in Scotland. By the fall of 1921 ten of the wells were completed; the remaining one, the D'Arcy in Scotland, was stopped some months later. The tests were deep ones, five of the wells being 4000 ft. or more, the rest varying in depth between 1810 and 3918 ft. The total footage drilled was 40,047 ft. The holes were put down with standard or cable tools purchased in the United States (except the boilers). The larger sizes of casing, 10-in. and above, were also from America, while the smaller sizes were secured in Scotland. The Hardstoft well in England found a small production of high-grade oil and the D'Arcy well also encountered what is reported as a favorable showing at a depth of 1810 ft. The Werrington and West Calder wells had to be abandoned on account of drilling difficulties. The Apedale well encountered great thicknesses of ash in the Carboniferous and had to be abandoned on account of depth. The results might be summarized by saying that of the ten structures drilled upon, two yielded encouraging showings; three cannot be considered as having been adequately tested; and five produced dry holes, although in some of these small oil showings and gas were met. The total cost of the work amounted to about half a million pounds sterling, which sum includes the cost of all equipment, subsequently sold by the government. The work, under the superintendence of V. L. Conaghan, took place for the most part in the period immediately following the war—a period of high prices, labor and transportation difficulties, and unsettled conditions generally; factors tending to retard the work and affect the costs. The writer, as a member of the staff of S. Pearson & Son, Ltd., had charge of the administration of the work during its later stages and

Jan 1, 1924