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By A. W. Hesse

Twelve years ago, some coal-mine operators, mining engineers, oil and gas operators, Bureau of Mines engineers, geologists and state mine inspectors met in Pittsburgh, Pa. to discuss and solve if possible, the problems in connection with the drilling of oil and gas wells through or near coal mines and through the future coal reserves. Regulations were drafted and presented by O. P. Hood and A. G. Heggem of the Bureau of Mines.' . There was considerable discussion of the various articles, practically all of which appear in Bulletin 65, but the interest aroused at that meeting was short lived. Practically none of the important coal-producing states gave the matter the consideration it should have received. Notwithstanding the marked progress in safety work, coal mines still have an unenviable reputation for mine explosions. Our mining laws have become stricter and the enforcement, especially in Pennsylvania, more rigid, but what good will come from a rigid enforcement of the mining laws if some source of danger exists all around the mines, over which the operators have no control ? It is hardly necessary to recite all the cases of natural-gas explosions published in Bulletin 65, but with some of them I am especially familiar. In 1912, while visiting the Miners' Hospital, at Fairmont, W. Va., my attention was called to a patient swathed in in bandages so that no part of his face and hands were visible. He had not been told that his two sons, mere boys, had died of the burns they had received in the same accident—explosion due to natural gas leaking into a country mine at Peora, Harrison Co., W. Va.

Jan 1, 1925

By Joseph Newton

MUCH the same story can be told about the copper industry for the year 1944 as for the three preceding years. Operators report few or no technical changes at their plants and the main endeavor has been to maintain high production with existing equipment. No large new installations have been made to increase plant capacities and apparently over-all copper production has passed its maximum. The present decline in copper production results partly from the severe labor shortage. As is true of most industries; the outstanding fact about the copper industry during the past few years has been its tremendous and sustained production which has been maintained in spite of serious shortages in material. labor, and technical personnel. The figures in Table I give a concrete example of how production has been increased at one large smelter in the United States-the Garfield plant of the American Smelting and Refining Co. at Garfield. Utah. These figures, reported by W. G. Rouillard. superintendent. give the production of the Garfield plant for the five years 1940-44 inclusive. The total blister production

Jan 1, 1945

By J. W. Downey, M. V. Nevitt

The phase boundaries for the 950" isothermal sections in the ternary systems Zr-Co-0 and `Zr-Ni-0 have been determined for the composition range from 50 to 100 at. pct Zr. The two systems show very similar phase relations, having no extensive solid solution phase fields. Each contains a ternary phase. These phases are apparently isostructural, but their structure has not been determined. Some aspects of the phase relations are discussed in terms of the alloying behavior of transition metals. THE work described in this paper is the outgrowth of a recent study of the occurrence of phases having the Ti2Ni-type structure (structure-type E9,) in certain ternary systems involving Ti, Zr, or Hf with another transition metal and O.", In the Zr-CO-0 and Zr-Ni-0 systems no Ti2Ni-type phases were found to occur. However, there are several interesting aspects of the phase relations in the two systems which have significance from the point of view of the alloying behavior of transition metals. The results of this investigation may also have some importance in studies of the oxidation of Zr-Co and Zr-Ni alloys. In both the Zr-Co-0 and Zr-Ni-0 systems only the 950" isothermal sections were investigated and, as a further restriction, the study was limited to the composition range from 50 to 100 at. pct Zr. A tentative Zr-Co binary diagram has been published by Larsen, Williams, and Pehin. In the composition range pertinent to the present work they report a eutectic at 980°C and 75.9 at. pct Zr, the products of which are the terminal solid solution based on /3 Zr and the compound Zr2Co, and a eutectic at 1080" and 64.8 at. pct Zr whose products are Zr,Co and ZrCo. The solid solution based on /3 Zr is shown to decompose eutectoidally at 826°C into a Zr and Zr2Co. The limits of solubility of Co in a and /3 Zr have not been established. The structure of Zr2Co is not identified in the publication just cited. Dwight has reported that ZrCo has the CsC1-type strcture. The Zr-rich portion of the Zr-Ni diagram has been determined by Hayes, Roberson, and Paasche." The phase relations are very similar to those of the ZrCo system. A eutectic reaction whose products are /3 Zr containing 2.9 at. pct Ni and Zr,Ni occurs at 961°c, and a eutectic between Zr,Ni and ZrNi is found at 985". The solid solution based on /3 Zr decomposes eutectoidally at 808°C. The solubility of Ni in a Zr is not known accurately but is believed to be very small. Smith, Kirkpatrick, Bailey, and Williams7 have found that Zr2Ni has a tetragonal structure of the A1,Cu-type and that ZrNi is orthorhombic. Domagala and McPherson8 have published a constitution diagram for the system Zr-ZrO,. At 950" their diagram indicates that the solid solution of 0 in 0 Zr is stable from 0 to 0.5 at. pct while the phase field of 0 in a Zr extends from 6 to 29 at. pct. These solubility limits were adopted in the present study and no binary Zr-0 alloys were made. No previous data on the phase diagrams of the ternary systems are known to exist. EXPERIMENTAL PROCEDURE The experimental details involved in the preparation of alloys in this laboratory by arc melting have been described in several previous papers"3 and they will not be repeated here. Information concerning the purity of the metals used is given in Table I. Oxygen was added in the form of reagent grade ZrO,. All of the cast specimens in both alloy systems were annealed in air-atmosphere tube furnaces at 950 3' for 72 hr and water quenched. The specimens were protected from oxidation by wrapping them in Mo foil and sealing them in quartz tubes that had been evacuated at room temperature to a pressure of 1 x 10B mm of Hg. The phase boundaries were determined by metallography, and identification of the phases was accomplished primarily by X-ray diffraction methods which employed a powder camera having a diameter of 114.6 mm. The diffraction techniques which are in use in this laboratory have been previously described.' An etchant that proved satisfactory for most of the alloys consisted of 5 pct by vol of AgNO

Jan 1, 1962

By R. J. Hopkins, L. B. Haney

On the basis of limited experimental work conducted at the Port Pirie smelter, it would appear that, by increasing the specific surface of sinter, and possibly that of coke as well, a marked increase in the rate and degree of sinter reduction in the furnace shaft can be achieved. Fusion-point tests have shown that this increased reduction means a much higher sinter fusion point and narrower plastic zone, while the more efficient utilization of coke in the furnace is inherent in the intensification of reduction by the provision of a more reactive sinter surface. Investigations aimed at increasing the ability to operate the blast furnace with a higher lead tenor of sinter reducing fuel cost proportionately, and at eliminating the loss in reduction potential in coke entering the furnace, as shown by the presence of appreciable proportions of CO in the top gases, are reported. Several lines for future investigations that could result in improved smelting methods are proposed. A SOMEWHAT informal presentation of ideas on lead blast-furnace smelting will be given in this paper. These ideas have been developed during observations of furnace behavior at Port Pirie and earlier at Mt. Isa, and have been guided by the results of laboratory experiments at Port Pirie. The authors do not intend to propound any particularly new theories, but present their ideas as a basis for discussion which may help toward a better understanding and improved control of blast-furnace operation. Performance variations of considerable magnitude occur from time to time at most lead blast-furnace plants. While Port Pirie is fortunate in having a very regular supply of high grade concentrates, it is no exception in this respect. Such irregularities are of considerable economic importance and they constitute a challenge to present-day metallurgists in their efforts to obtain an ever greater degree of control over furnace operation. In operating as Port Pirie does with a relatively high lead charge, it has been recognized for a long time that shaft conditions are ,of the greatest importance. A practical, or engineering, attack on the problem of accretions consisted of changes in furnace design, e.g., by widening the shaft to 10 ft above the bottom row of tuyeres, and by the provision of curved ends and vertical walls.' That this attack has had a great measure of success is shown by the fact that barring down of these wide furnaces is rarely necessary, shaft conditions have greatly improved, and sensitivity to charge variations has been markedly reduced. These modifications, followed by some metallurgical changes (chiefly the incorporation of pig iron into the furnace charge in 1948), have brought furnace operation to a point where some variables which were previously masked can now be studied. Accordingly, over different periods of time during the last five years, such variables as could be given numerical values have been recorded and subjected to statistical examination. The objectives of this work were: 1—to reveal the true importance of the different variables and 2—to show the proportion of total furnace variation which is unexplained and therefore referable to causes not measured at present? e.g., shaft accretions, sinter structure, coke structure, and others. Statistical Study of Variables In this work factors relating to furnace speed and lead reduction have been examined: 1—slag com-

Jan 1, 1955

The Fifth Annual National Exposition of Chemical Industries will be held in Chicago at the Coliseum and First Regiment Armory during the week of Sept. 22. It was decided to hold the exposition in Chicago, this year, for two reasons: The U. S. Army commandeered the Grand Central Palace Exposition Building in New York, immediately on the close of the last exposition and converted it into a receiving hospital, the use for which is now, happily, nearly ceased; and it was thought that the Exposition would succeed in bringing about a greater development of chemical industries in the Chicago district and the adjoining states. The Advisory Committee of the Exposition consists of: Charles H. Herty, Chairman, Editor Journal of Industrial and Engineering Chemistry; Raymond F. Bacon, Director, Mellon Institute; L. H. Baekeland, Member Naval Consulting Board; W. D. Bancroft, President, American Electrochemical Society; Henry B. Faber, Industrial Filtration Corpn.; Ellwood Hendrick, President, The Chemists' Club; Bernard C. Hesse, Chemist, General Chemical Co.; A. D. Little, President, Arthur D. Little Inc.; Wm. H. Nichols, President, American Chemical Society; R. P. Perry, Vice-president, The Barrett Co.; H. C. Parmelee, Editor Chemical &; Metallurgical Engineering, G. W. Thompson, President, American Institute of Chemical Engineers; T. B. Wagner, Vice-president, U. S. Food Products Corpn.; M. C. Whitaker, President, U. S. Industrial Chemical Co.; and Charles F. Roth and Fred W. Payne. There is also added a special Chicago committee consisting of L. V. Redman, W. D. Richardson, A. V. H. Mory, Carl S. Minor, F. W. Willard, and Wm. Hoskins; the managers, as in the past, are Charles F. Roth and Fred W. Payne.

Jan 6, 1919

By Robert Glass Cleland

Anson G. Phelps 1834-1853 Anson G. Phelps, Jr. 1839-1858 Charles C. Dodge 1864-1878 Daniel James 1834-1878 [ ]

Jan 1, 1952

By W. B. Price

AT the New York meeting of the American Institute of Mining and Metallurgical Engineers held in February, 1926, W. H. Bassett and J. C. Bradley presented a paper entitled "Exudations on Copper Castings."' The purpose of the present paper, as the title suggests, is to call attention to somewhat similar phenomena which the authors have encountered in brass and bronze. From a study of the examples given, a more-or-less speculative theory of "inverse segregation" is advanced. Protuberances on Admiralty Brass In the rolling mill of the Scovill Manufacturing Co., there have been found quite commonly bars of certain alloys which had a sort of shaggy roughness on the surface due to slight metallic protuberances. No special attention was paid to these until some bars were found on which these protuberances were heavy enough at the bottom of the bars to produce a blistered appearance. A sample of the protuberances was milled off the surface of the bar illustrated (Fig. la) and upon analysis was found to contain 66.66 per cent. copper, 4.02 per cent. tin and 0.03 per cent. lead, whereas the average composition of the bar was 70.21 per cent. copper, 1.21 per cent. tin, and 0.01 per cent. lead. A sample of the shaggy-rough protuberances at the very top of a bar was also analyzed and was found to contain 2.45 per cent. tin, indicating that it was probably of the same origin as the blistered areas. These results were not entirely unexpected for previous analyses of this alloy had revealed that the surface was richer in tin than the rest of the bar. This, of course, is contrary to what we would expect from a consideration of the equilibrium diagram and has been called "inverse segregation." Fig. 16 is a cross-section of a bar through the protuberances on the surface. It reveals that there is a decidedly different structure through the raised areas and seems to indicate that the bar originally solidified

Jan 1, 1927

By T. C. Campbell

Copper is extracted from the Chuquicamata oxide ore by a hydro-metallurgical process. The ore is crushed to 3/8-in. sizing, and leached with a sulfuric acid electrolyte. Chlorine is precipitated. and the ferric iron reduced in the enriched electrolyte, after which the copper is recovered by electrolysis with insoluble Chilex and lead-antimony anodes, the spent electrolyte being returned to leaching. Cathodes are melted and refined in market furnaces and cast into commercial wire-bar and cake shapes. Sulfuric acid for the process is supplied by the brochantite in the ore. Water for washing the ore is advanced through the solution system and finally after cutting by electrolysis to from 6 to 16.0 grams per liter is completely stripped by the cuprous chloride method and run to waste. The cuprous chloride so obtained plus that resulting from precipitation of chlorine from strong solution is dissolved in ferrous chloride brine and the copper cemented on scrap iron. The cement so obtained is in part used to reduce ferric iron in electrolyte, and as it is of exceptional purity is also furnace refined and cast into an exceptional quality of fire-refined copper. Fig. 1 is flow sheet of the operation. The reduction plant is composed of seven divisions as follows: (1) crushing, (2) leaching, (3) tailings disposal, (4) dechloridizing, (5) sulfur dioxide treatment, (6) electrolytic tank house, (7) smelting and melting. A brief description of each of these divisions will be given. Crushing Ore that is frequently blocky and up to 5 ft. in section is crushed in four stages to 3/8-in. mesh. The first stage of crushing is called primary and the next three stages are known as secondary crushing. The first stage is accomplished with two 60-in. Superior McCully gyratory breakers by which the ore is broken to 9 in. The second coarse gyratory breakers crush the ore to 3-in. sizing. There are seven No. 10 McCully gyratories in this service, for one of which recently has been substituted a No. 7 cone crusher. The third and fourth stages of crushing are accomplished by fifty 48-in. disk crushers. In the third stage 14 disk crushers break the ore to 1 in., and in the last stage 36 disk crushers turn out the final product of 0.371-in. sizing. Reference to the flow sheets of Figs. 2 and 3

Jan 1, 1934

By F. R. Brotzen, J. Taranto

SEVERAL investigators have computed stacking-fault concentrations from X-ray diffraction data.'-' The method generally employed relates the line shift to the stacking-fault probability. In this investigation platinum filings of 99.99 pct purity screened to -325 mesh were studied after having been subjected to various annealing treatments. The lines were measured on a General Electric XRD-5 spectrogoniometer using CuK, radiation. The centroid of the broad reflections was determined by the method proposed by pike.' The stacking-fault probability was calculated by the formula given by Warren and warekois,3 with the assumption that all stacking faults were on the (111). Various high-angle reflections were used, but most data collected refer to the shift in the (400) reflections. When the filed platinum powder was annealed at 1200°C for 20 min the stacking fault concentration was too small to be detected. The stacking-fault probability in freshly filed specimens, as determined by the line shift relative to the annealed specimen, was about 0.016, Fig. 1. If the faults would be created only by extended dislocations, the dislocation density in the filed specimen would be about 3X1012 cm-2. The average stacking-fault width of about 21 which was used in this computation, is that given by Thornton and Hirsch.7 The mechanism by which stacking faults are annihilated during annealing is not yet fully understood. The isothermal results obtained do not seem to support the simple hypothesis of a first-order decay. On the other hand, the analysis by Kuhlmann, Masing, and Raffelsieper8 for the loss of dislocations during recovery agrees much better with the experimental data of this investigation. This analysis yields an activation energy of 29 ± 8 kcal per mol for the disappearance of stacking faults in cold-worked platinum during annealing. Even if one takes into account the lack of accuracy inherent in this X-ray method, the activation energy found is substantially less than that of self-diffusion in platinum, i.e., 61.6 kcal per mol.9 The results therefore suggest that processes other than dislocation climb, which involves the activation energy of self-diffusion, are responsible for the loss of stacking faults in platinum during annealing. The broad reflection lines became sharper early in the recovery process, Fig. 1. The sharpening occurred well before the stage during which stacking faults disappear. This lends support to Nowick's10

Jan 1, 1962

By R. S. Busk

Niels Engel (University of Alabama, University, Ala.)— In this paper it was pointed out that the electron-gas and energy-band theory accounts for the fact that the lattice parameters exhibit a sudden change when the electron concentration (number of bonding electrons per atom) exceeds a certain number around two. This statement is said to support and prove the electron-gas theory. But this theory is not able to account for a series of experimental data. Also several expectations, deduced from this theory, are not found to exist. In Figs. 6 and 7 the energy bands of the second and third periods are given as they must be assumed in order to account for the electrical properties of the elements in these periods. In Figs. 6 and 7 the electron-gas and energy-band theory is compared with the electron-oscillator hypothesis in accounting for the properties of the elements in the second and third periods. Fig. 6 shows the second period, The energy-bands are overlapping and separated to be in agreement with the electrical conductivity of the elements. The oscillator hypothesis explains conductivity due to electron vacancies. In graphite there is a closed s-shell in every other atom and two vacancies in the others. Conductivity is therefore only maintained by migration of s-electrons in graphite. In boron there are no s-electrons. The diatomic molecules of nitrogen and oxygen and the paramagnetism of oxygen can be accounted for by a similar behavior as the s-electrons of the bonding electrons. But this explanation will deviate too much for the purpose of this discussion. Fig. 7 shows the third period. In the energy-band picture about two s-electrons are assumed in magnesium and aluminum, but only one s-electron is assumed in silicon. The diamond lattice is assumed to be controlled by a sp3 hybrid. However the electron distribution develops ideally according to the oscillator hypothesis. Only sodium, magnesium, and aluminum exhibit electron vacancies and conductivity. To account for the insulator properties in Si, P, and S in the third period it must be assumed that the four last added p-electrons must be taken up in bands containing only one electron per band.' (Compare the electron band picture in Hume-Rothery.' Hume-Rothery does not consider the insulator properties of the nonmetals.) In the second period already the first p-electron must have entered a single electron band. Based on the energy-band picture in Figs. 6 and 7, the following questions must be asked: 1—Is it consistent with the energy-band idea that electrons of the same kind (p-electrons) can be divided into separated bands? 2—Is it consistent with the energy band idea that single electron bands can exist? 3—Why are the first two p-electrons (in boron and diamond) separated into two single electron bands in the second period, but overlapping in the third period (aluminum)? 4—Why are s-electrons and d-electrons taken up in continuous overlapping bands, while p-electrons are divided into single electron bands? 5—Why do the peaks and valleys (y and w and further x and z) of the energy band below four electrons per atom not show up in the electrical conductivity of alloys? For example consider the Li-Mg system or the alloys between Mg and three electron metals where the mentioned discontinuity in the lattice parameter is found. 6—Why does the beginning of the p-electron band (x) not show up in the lattice constants similar to the filling up of the s-electron band (z) ? In magnesium alloys the electron-gas theory postulates the first Brillouin zone to be filled at about two electrons per atom. This is claimed to explain the sudden change in lattice spacing and c/a values of several magnesium alloys when the electron concentration exceeds a few percentage points over two electrans per atom. This was emphasized in the paper by Busk. If the electron-gas energy-band theory is correct a sudden change in electrical conductivity and possibly other properties .should be expected when the same electron-concentration or temperature is exceeded. A sudden change in lattice spacing or other properties should also be expected when the filling degree is such that p-electrons are introduced into the p-band, for example at x in Figs. 6 and 7. Such phenomena are at found by experiment. and If the number of electrons should vary with the energy level depending on the average number of bonding electrons per atom, the electrical conductivity should be expected to vary in accordance with the energy band layout (Figs. 6 and 7) caused by different numbers of conducting electrons at different filling up degrees. Nothing indicating such a behavior is observed. In addition to these discrepancies between the electron-gas and energy-band theory and measured data, the theory violates the principles developed along with the Bohr theory of atomic structure. According to these principles a filled shell is saturated and therefore unable to form bonds. Therefore two S-electrons per atom should form a closed or saturated shell, which has been pointed out as accounting for the inability of helium to form bonds. Beryllium, magnesium, or calcium atoms with two s-electrons should be expected to form inert atoms with properties almost like the helium atoms. Several other inconsistencies and disagreements with measured data of the energy-band theory can be mentioned. Some of these are discussed with reference to other papers. 8 Because the electron-gas and energy-band theory seems to fail on several points, I have developed another theory which can account for all the phenomena the electron-gas theory is able to account for. This new theory is further able to account for things which are impossible to explain by the electron-gas theory at the present state.

Jan 1, 1953

By D. W. Fuerstenau, D. A. Sullevan

In the experimental work for this comparison of wet and dry grinding, it was found that the size distributions for wet grinding operations are characterized by a constant value of the distribution modulus, (a; whereas, for dry grinding the distribution modulus decreases slightly with increased size reduction. Wet grindability seems independent of the weight of material in the mill while dry grindability depends on weight. Experimental data and eqmtions for each process are presented for noncleavable isotropic material, for cleavable or material in which there is some form of internal stress, and for energy consumption. The equation ED/EW=BK-? (where ED and Ew are, respectively, energy for wet and dry grinding, k is the size modulus, and B and ? are constants) was found to give the ratio of energy. Dry grinding is generally considered to require more energy than wet grinding. Taggart' states that power consumption in wet grinding ranges from 60 to 90 pct of that required for dry grinding. Bond' states that dry grinding requires one third more power than wet grinding. It is interesting that Rose and Sullivan' note this same difference in power required for wet and dry grinding, but they state that on purely mechanical grounds it is difficult to see any great difference in fundamental principles between wet and dry milling, since dry milling may be regarded as wet milling with a fluid of low viscosity (i.e., air vs water). Yet it must be the viscosity of the fluid that is responsible for the differences between wet and dry grinding. Probably the most comprehensive investigation comparing wet and dry grinding has been that made by Coghill and Devaney. They compared the grind-ability of both chert and dolomite in a 19x36-in. batch ball mill under both wet and dry conditions. In these tests the weight of ore in the mill was varied from 35 to 200 lb and each grinding test was carried out for such period of time that the amount of -200-mesh material in the product was essentially the same for each test with a given material. Cog-hill and DeVaney's data for the grindability of dolomite, which are reproduced in Fig. 1, show that a comparison between wet and dry grinding is com- plex. The comminution of a material by a wet grinding method is characterized by a constant grindability over a wide range of mill loadings. Since grindability is the weight of material comminuted per unit of energy expended, it is equivalent to (w)/ (p)(t), where W is the weight of material being ground, P is the power, and t is the grinding time. In the case of wet grinding, the grindability of dolomite in the Coghill and DeVaney experiments was 0.546 * 0.009 ton per hp-hr when the load of dolomite in the mill ranged from 50 to 200 lb. On the other hand, for dry grinding no such simple relationship was found to exist between power, time, and weight of material in the mill. Dry grinding efficiency appears to depend greatly upon the amount of material within the mill. When the mill contained

Jan 1, 1961

By A. E. J. Engel

INDUSTRIAL talcs and ground soapstones both include earth materials of different chemical and mineral compositions. In general, the industrial talcs are composed of silicates that contain appreciable amounts of magnesia. Generally talc, the mineral, is a predominant or at least common constituent. Talc, the mineral, is a hydrous magnesium silicate, with a suggested theoretical formula H2Mg3 (SiO3)4 or H2O.3MgO.4SiO2, which postulates 63.5 pct SiO2, 31.7 pct MgO, and 4.8 pct H20.11 Actually different single grains or leaves of pure talc have variations in water content ranging from 3.5 pct to more than 7 pct, as well as slight differences in the proportions of MgO and Si02.16 Only a very small percentage of the ground industrial talcs produced in the United States approaches the composition given above (see Table 1). The purer talcs invariably occur as alteration products of magnesium carbonate rocks. Some of these relatively pure talcs include compact, massive types largely mined in California, which are designated as steatite.38,58 In general, steatites cannot contain in excess of 1.5 pct CaO, 1.5 pct combined FeO and Fe203, and 4 pct A1203. The less pure varieties of massive talc and mixtures of magnesian silicates are commonly called soapstones, or merely talc. Many industrial earth products classified as talc or as soapstone contain a variety of minerals, especially serpentine (H4Mg,Si2O9), chlorites (hydrous magnesium, iron, aluminum silicates), tremolite (Ca2Mg5H2[SiO3]8), anthophyllite ([MgCa]SiO3), diopside (CaMg[SiO3]2), and quartz (SiO2). The carbonates calcite (CaC03), dolomite (CaMg[CO3]2), and magnesite (MgCO3) are also present in some industrial talcs and soapstones. Some of these minerals, as well as sulphides, sulphates, and iron and manganese oxides, if present at all or in excess of minute amounts, may alter the composition of the industrial talc sufficiently to restrict materially its use or to lower or destroy its value. These factors are discussed in a subsequent section of this chapter.

Jan 1, 1949

By Wilbur H. Somerton

W. H. Somerton is to be commended for his application of the methods of dimensional analysis in combination with the results of laboratory drilling tests to obtain a significant formula for the rate of penetration for the process of rotary drilling. This formula is shown to be a consequence of a more general formulation developed by the discussor as a result of his investigations of the basic action of most methods of rock drilling by mechanical means—the momentary loading of a chisel-shaped tool on the surface of the rock at the bottom of the hole. Some of the author's conclusions are re-examined in the light of this general formulation. DRILLING RATE FORMULA The author selects a minimum number of the most significant variables associated with the rotary drilling process to set up his two dimensionless parameters. Only one variable is associated with the geometry of the bit —the bit diameter, D; only one variable is associated with the properties of the rock pertinent to drilling— the drilling strength, S; and only two independent variables are associated with the conditions of operation the weight on the bit. F, and the rate of rotation, N. The dependent variahle of interest is, of course, the rate of penetration, R. The results of the author's drilling tests show that the variable R that appears in the dimensionless parameter, RIND is approximately proportioned to the square of the variable, F, that appears in the other dimension-less parameter, F/D2S. This establishes the functional relationship between these two simple parameters that leads to the formulation of a third dimensionless parameter, RD1T2/NF1. This last parameter is a significant one for the rotary drilling process, in general, although the author properly limits the validity of his equations to his present test conditions. The author realizes that the numerical value of this parameter, C, is not a constant but may be a function of one or more additional dimensionless groupings of the many other variables associated with the rotary drilling process, e.g. some dimensionless measure of bit wear. The author's parameter is shown to be a special case of a more general dimensionless parameter, developed by the discussor. that is applicable to practically all methods of rock drilling by mechanical means, namely. RD2S/P. P is the rate at which mechanical work is done on the rock, and S is the drilling strength, a term originated by the discussor. S is defined as the ratio of energy input to the rock to the volume of rock broken

By Enid C. Plante

INTRODUCTION To extend our knowledge of the flotation behavior of sulphide minerals, the response of the following minerals to ethyl xanthate as collector was studied by captive bubble and cylinder flotation tests: antimonite (Sb2S3), arsenopyrite (FeAsS), covellite (CuS), marcasite (FeS2), orpiment (As2S3), pyrrhotite (FeS) and tetrahedrite (4CU2S, Sb2S3). Lollingite (FeAs2) was also examined to determine if its behavior could be correlated with that of pyrite or marcasite (FeS2). EXPERIMENTAL METHOD Mineral for Flotation and Contact Tests Mineral was prepared in the manner already described' and its behavior both freshly ground and "oxidized" was studied. Tests in which the mineral was allowed to oxidize for various periods showed that a uniform response to xanthate was reached in two days or less. Oxidation Products The soluble oxidation products from most of the above minerals were measured and their effect on the flotation of the mineral studied. The mineral samples were wet ground to minus-52 mesh and deslimed, and 20 g of this material placed in 200 ml of distilled water of a measured pH value, and C02 free air bubbled through each suspension at a constant rate (about 1 bubble/sec) for 5 days. It has been shown1 that the size of the mineral is unimportant in the rate of formation of oxidation products and that probably the supply of oxygen to the mineral is the rate-determining step. At the end of 5 days the pH value of the supernatant liquid was measured again, the mineral filtered off and the soluble products determined. Methods for estimation of sulphur acids, ferrous and ferric iron and copper have already been described.1 No satisfactory method was found for antimony. Arsenic was estimated as the arsenate.2 FLOTATION OF "UNOXIDIZED" MINERALS WITH ETHYL XANTHATE AS COLLECTOR Fig I to 3, 4, 6, show the effect of alkali and cyanide as depressants for the minerals with 25 mg potassium ethyl xanthate per liter as collector at 35°C. Wark and Cox3 have shown that with ethyl xanthate as collector, galena, pyrite and chalcopyrite show a greater tolerance to cyanide and hydroxyl ions at room temperature than at 35°C. Covellite (Fig I), marcasite (Fig 2) and pyrrhotite (Fig 3) behave similarly. The independence of the curves for pyrrhotite at 35°C with respect to cyanide

Jan 1, 1947

By R. V. Norris

IRving Ariel Stearns died at his home, 60 South River St., Wilkes-Barre, Pa., on Tuesday morning, Oct. 5, 1920, of pneumonia, after an illness of about a month. In his death, the Wyoming Valley loses one oflits most eminent and best loved citizens, and the loss of so strong a participant in the activities of the Valley will leave a gap most difficult to fill. Despite his more than three score and fifteen years, Mr. Stearns, at the time of his death, was president of the Wilkes-Barre City Hospital, Wyoming National Bank, and the Wyoming Historical and Geological Society, chairman of the Board of the Vulcan Iron Works, and a director of the Spring Brook Water Supply Co., and of the Wilkes-Barre Lace Manufacturing Co. Mr. Stearns came of New England stock, a descendant in the eighth generation of Charles Stearns who was admitted freeman in Watertown in 1646. Irving Ariel Stearns was born Sept. 12, 1845, in Rushville, N. Y., a son of George W. and Miranda (Tufts) Stearns. He was graduated from the Rensselaer Polytechnic Institute of Troy, N. Y., in the celebrated Class of 1868. After graduation, he was assistant professor of chemistry in charge of the analytical laboratory for a year, then went to Wilkes-Barre in 1869, as engineer in the office of R. P. Rothwell, at that time the leading mining engineer of the region. From 1871 to 1872, he was superintendent of the McNeal Coal & Iron Co. of Schuylkill County, Pa. and in 1872 succeeded to Mr. Rothwell's business when the latter became editor of the Engineering & Mining Journal of New York. From 1872 to 1885, Mr. stearns was in private practice as a mining engineer, handling a great amount of business in the anthracite region, including the building of the bridges at Shickshinny and Pittston, and the surveying and mapping of many of the individually operated mines. His practice extended throughout the country, with numerous examinations and reports upon mining properties in Pennsylvania, Virginia, West Virginia, Arkansas, Colorado, California, Wyoming, Idaho and Utah; he was responsible for the design and execution of the Lehigh Valley Railroad Co.'s great Tifft Farm improvements at Buffalo, N. Y. including canals, docks, coal stocking plant, etc. He was commissioned Quartermaster of the Ninth Regiment, N. G. P., March 29, 1880, was promoted to Major on May 15, 1884, and resigned Apr. 1, 1885. He always retained his interest in the National Guard and was trustee and president of the Ninth Regiment Armory Association.

Jan 1, 1922

By R. V. Norris

IRving Ariel Stearns died at his home, 60 South River St., Wilkes-Barre, Pa., on Tuesday morning, Oct. 5, 1920, of pneumonia, after an illness of about a month. In his death, the Wyoming Valley loses one oflits most eminent and best loved citizens, and the loss of so strong a participant in the activities of the Valley will leave a gap most difficult to fill. Despite his more than three score and fifteen years, Mr. Stearns, at the time of his death, was president of the Wilkes-Barre City Hospital, Wyoming National Bank, and the Wyoming Historical and Geological Society, chairman of the Board of the Vulcan Iron Works, and a director of the Spring Brook Water Supply Co., and of the Wilkes-Barre Lace Manufacturing Co. Mr. Stearns came of New England stock, a descendant in the eighth generation of Charles Stearns who was admitted freeman in Watertown in 1646. Irving Ariel Stearns was born Sept. 12, 1845, in Rushville, N. Y., a son of George W. and Miranda (Tufts) Stearns. He was graduated from the Rensselaer Polytechnic Institute of Troy, N. Y., in the celebrated Class of 1868. After graduation, he was assistant professor of chemistry in charge of the analytical laboratory for a year, then went to Wilkes-Barre in 1869, as engineer in the office of R. P. Rothwell, at that time the leading mining engineer of the region. From 1871 to 1872, he was superintendent of the McNeal Coal & Iron Co. of Schuylkill County, Pa. and in 1872 succeeded to Mr. Rothwell's business when the latter became editor of the Engineering & Mining Journal of New York. From 1872 to 1885, Mr. stearns was in private practice as a mining engineer, handling a great amount of business in the anthracite region, including the building of the bridges at Shickshinny and Pittston, and the surveying and mapping of many of the individually operated mines. His practice extended throughout the country, with numerous examinations and reports upon mining properties in Pennsylvania, Virginia, West Virginia, Arkansas, Colorado, California, Wyoming, Idaho and Utah; he was responsible for the design and execution of the Lehigh Valley Railroad Co.'s great Tifft Farm improvements at Buffalo, N. Y. including canals, docks, coal stocking plant, etc. He was commissioned Quartermaster of the Ninth Regiment, N. G. P., March 29, 1880, was promoted to Major on May 15, 1884, and resigned Apr. 1, 1885. He always retained his interest in the National Guard and was trustee and president of the Ninth Regiment Armory Association.

Jan 1, 1922

By CHARLES F. DEISS

The total pipe-line runs of petroleum in Indiana during 1945 were 4,114,000 bbl., a decline of nearly 17 per cent below the estimated 4,950,000 bbl. produced in 1944. Drilling activity during the year was centered in Posey and Gibson Counties, where seven new pools were discovered in the state. Four of the pools are in Posey County-Crunk, Farmersville, Jeffries and St. Wendells East-and the other three are in Gibson County-Johnson West, Lysle and Mt. Carmel East.

Jan 1, 1946

By R. A. Oriani

The partial molal volume of hydrogen is one of the parameters that describe the elastic interaction between the solute and the stress fields about inclusions, dislocations, and cracks. As such the partial molal volume is probably of importance in the elucidation of phenomena such as hydrogen embrittlement and hydrogen yield point. A knowledge of this quantity would also be helpful in thinking about the state of dissolved hydrogen in iron. However, because of the very low lattice solubility of hydrogen in iron the usual ways of determining the lattice expansion are not practicable. It is therefore of interest to apply the thermodynamics of stressed bodies to two sets of measurements of the effect of elastic stress upon the permeability of hydrogen in order to deduce a value of the partial molal volume, VH, of hydrogen dissolved in a iron. Beck ..' and previously de Kazinczy, observed that a uniaxial tensile stress increases the permeability of hydrogen in iron and in various steels. Beck et 01. employed Armco iron and A.I.S.I. 4340 steel, whereas de Kazinczy used a steel the composition of which was 0.13 C, 0.23 Si, 0.46 Mn, 0.006 P, and 0.038 S. Upon releasing the stress the permeability increment disappeared if the stress was below the elastic limit. Both investigators employed cathodic charging to introduce the hydrogen. de Kazinczy measured the permeation through a thin-walled tube by collecting the gas, whereas Beck et al. measured the permeation through sheets of various thicknesses by a very sensitive electrochemical technique. Both investigators measured the steady-state permeation at constant rate of hydrogen ion discharge, and Beck measured in addition the hydrogen diffusivity by a time-lag technique which is independent of the boundary conditions. Beck et al. and de Kazinczy found a linear relationship between log (J,/Jo) and the stress, where Ju/Jo is the ratio of the flux of hydrogen when the metal is under uniaxial tensile stress, a, to the flux under zero stress, for the same temperature and charging current. Beck et al. found in addition that the diffusivity of hydrogen is not changed by stress. Both investigators concluded that the observed change in permeability is due to an increase in hydrogen concentration, and furthermore that the increase in concentration is due directly to the thermodynamic effect of stress upon concentration. Accepting this assessment of the situation for reasons given below, one may use the equation3j4 in order to evaluate I/H, the partial molal volume of hydrogen. This equation is valid for the domain of a/E «¦ 1 (where E is the Young's modulus) and under the assumption that hydrogen expands the lattice isotrop-ically. From the data of Beck el al, one calculates V7H - 2.0 cu cm per g-atom, and from those of de Kazinczy one obtains 1.8 cu cm per g-atom. That the increase of concentration with stress is indeed of thermodynamic origin is attested to by the facts that the experimental results conform to the thermodynamic relation, Eq. [I], and that the results are the same whether a pure iron1 or each of two different steels172 is used. Neither of these facts wou1.d necessarily be expected if the effect of stress were, rather, to increase the ratio kn/k, of the kinetic factors of the following competing reactions: H(ads) — H (dissolved) Such a change of kinetics at the surface could be an alternative explanation of the effect of stress on the permeability. Although this writer does not deem this explanation to be the correct one for the reasons given above, it must be admitted that unambiguous proof that the phenomenon has a thermodynamic origin does not yet exist. Two kinds of experiments may be suggested. One is to plate a variety of metals on the input surface of the steel and repeat the stress experiment at a variety of hydrogen charging currents. The other is to employ somewhat thicker specimens in order to be able to apply uniaxial compressive stress. Eq. [I] shows that ln(c,/c,) depends on the sign of the stress, but it is difficult to see a physical basis for which k2/kl would depend on the sign of a. The present value of V^ in a iron agrees with phragmen's5 estimate, which he based on comparisons with the lattice expansion by hydrogen of titanium, zir-

Jan 1, 1967

By David W. Brunton

FROM the old-fashioned " grab-sample " to the modern timing- . device, which takes a machine-sample with mathematical precision, there is a wide gap which was only crossed' by many years of toil and unremitting endeavor. Even to-day, notwithstanding the advancement in the art, "grab-sampling" is still practiced-sometimes to afford the unscrupulous mine-promoter a basis for fairy-tales with which to entrap the too-gullible investor, and often by milling and smelting companies to determine the amount of moisture in custom-ores. The latter practice is almost as reprehensible as the former, and it causes more trouble and ill-feeling between seller and buyer than all other factors put together. No reputable concern to-day would think of attempting to determine by grab-sampling the amount of gold, silver, lead, or copper contained in an ore, and yet many buyers expect the miner to accept the results of grab-sampling in the determination of the amount of water contained in the ore, forgetting that accurate results are just as necessary here as in the determination of the metals, because the result determines the percentage of weight of the ore which shall be excluded and considered to have no value whatever. Samples for the determination of moisture should be taken with as great care as samples for the determination of. metallic content, and in order to avoid the extra expense of a separate operation moisture-samples should be taken from the sample-safe. As the sample reaches the sample-bin in a smaller stream and by a more circuitous route than the "reject" travels in its path to the outgoing car, it loses more moisture en route, and a constant should be added to compensate for this difference. Carefully-conducted experiments have shown that the difference in loss of moisture between the two routes does not exceed 10 per cent. in summer and 7 per cent.. in winter. For instance,

Aug 1, 1909

By James P. Savely, Victor L. Kastner

Inspiration Consolidated Copper Company is currently mining in four pit areas; Live Oak, Red Hill, Thornton and Joe Bush Extension, near Globe, Arizona. Small satellite orebodies lying outside the main pits have been mined out in a series of small open pits. Major slope instability has affected production in every pit. Some consequences of the instability have been; (1) Serious interruption of mining plans, which resulted in deferred ore production, lost ore, reduced mining rates and increased stripping requirements. (2) Forced replacement of crushing facilities. (3) Serious effects on other production facilities. The introduction of a slope stability monitoring and control function as an integral part of mine planning has been successful in reducing the impact of these failures and will eventually result in economic pit design based on probabilistic slope analysis. This case history presents a brief review of the problems associated with slope instability at Inspiration's mines followed by a more detailed report on one specific failure area in the Thornton pit where the use of horizontal drain holes for slope stabilization appears to be successful. Relationships between slope movement rate, rainfall, and mining activity are shown.

Jan 1, 1983