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By W. H. Caruthers

ECONOMIC utilization of all by-products has long been the goal of American industry. One of the first groups that was popularly supposed to have achieved its aim was the meat-packing industry, which reputedly found a use for everything except the squeal of the hog. To the metallurgist, slag has always been the principal wasted by-product, representing a loss not only of material, but of heat. Slag does not possess many qualities that appeal to man's imagination or suggest a romantic influence on the daily life and progress of a community or nation. It is a bulky product, and space for its disposal within reasonable hauling distance of a smelter is not always available; the iron-ore smelter especially has been wont to find space for slag disposal at a premium. Therefore, the success that has been attained in recent years in finding a use for iron blast-furnace slag is notable. It has become a vital economic factor in the construction industry in areas where it is available. Its use may suggest further possibilities of an economic outlet for the slags from nonferrous smelting as well.

Jan 1, 1940

By L. R., McLeod

NO important changes in metallurgical practice are exhibited in the smelter that has been erected for treating the Morenci concentrate: the material is charged to reverberatory furnaces without roasting, and the matte subsequently blown in Peirce-Smith converters to separate the iron and sulphur from the copper. In fact the process is essentially the same, except for preliminary roasting of the concentrate, that was adopted in the new smelter that was built for the Arizona Copper Co. at Clifton, a few miles away, to treat Morenci concentrate just before the start of the first World War, and which went into service in October, 1913.

Jan 1, 1942

By AIME AIME

The Institute Headquarters at Spokane was established at the Spokane Hotel, and included a Bureau of Information for the benefit and comfort of members and guests of the party during the time of the meeting. The first session, held Tuesday afternoon, Sept. 28, 1909, in the beautiful Convention Hall ,of Masonic Temple, was called to order by Mr. E. J. Roberts, Chairman of the Spokane Local Committee, who introduced Mr. J. C. Ralston, City Engineer, representing the Mayor of Spokane and the Spokane Chamber of Commerce. Mr. Ralston extended to the members and guests of the Institute a cordial welcome to the city of Spokane, substantially as follows:

Dec 1, 1909

By G. Y. Chin, M. T. Dolan, W. L. Mammel

We have obtained by computer methods the solutions of the Taylor analysis1 for axisymmetric flow in bcc metals. Four modes of slip have been treated in detail:2-4 (111), {112}(111), {123}( 111), and a mixture of all three. In addition to obtaining anisotropy of strength data for randomly oriented or textured polycrystalline material,4 we have also obtained the lattice rotation resulting from slip on the predicted systems. The patterns of lattice rotation are essential to an improved understanding of texture development during deformation. The present note shows the results of lattice rotation for 5 pct axisymmetric compression, for fifty-two axial orientations distributed at 5-deg intervals throughout the standard stereographic triangle. The data are presented in Figs. 1 to 4 for the four modes of slip. The lattice rotation is indicated by a vector, the ends of which correspond to the positions before and after the deformation. The different vectors emanated from a given orientation represent different combinations of five slip systems that satisfy Taylor&apos;s minimum shear criterion.&apos; Fig. 1 shows the results for {110}< 111> slip. They are similar to those obtained by Bishop5 for the case of (111 )(110) slip in axisymrnetric tension, since in axisymmetric flow the sense of lattice rotation for {111)( 110) in tension is the same as that for (110) (111) in compression. The pattern of lattice rotation may be divided into three regions: region A in which the rotation is toward [100]; region B, toward [lll]; and region C, toward either [ loo] or L lll]. Although some slip combinations in region C lead to [1101, the latter is not stable as continued activity of the same combinations will eventually move the axis toward [loo] or Llll]. It may also be noted that [loo] is itself not stable. However, close inspection of the vectors in region A shows that it is impossible for an axial orientation within A to rotate outside its boundary. Hence after heavy compression, all orientations from A and some from C are expected to form a diffuse band in the [100] vicinity. By far the largest region is B. Here all orientations rotate to [lll], which is a truly stable position. Thus the [111] texture component is expected to be rather sharp. For the case of (112 }( 111) slip, Fig. 2, region C is enlarged at the expense of A, with B about the same as for {110}( 111) slip. A significant difference, however, is that [loo], as well as [Ill], is now truly stable. Fig. 3 shows the results of slip on {123}( 111) systems. Region B is substantially enlarged at the expense of C, with A being intermediate in size between the {110}(111) and {112}(111) cases. Like the case of {110)( 111) slip, [100] is itself unstable. However, the lattice rotations here are confined to less than 5 deg; hence it may be considered "stable" for practical purposes. Finally, Fig. 4 shows the results of mixed slip. Here region B is the largest, and C the smallest, of all the cases considered. Both [loo] and [ill] are stable. The behavior of the three corner positions is, in fact, identical to the case of {112)( 111) slip, Fig. 2; it turns out that in these positions for the mixed slip case, all the active slip systems (based on Taylor&apos;s criterion) belong to pure {112}( 111) .4 In summing up the results for the four modes of

Jan 1, 1968

By AIME

WE got our chance to talk with Arthur J. Blair at the Annual Meeting at the Pennsylvania Hotel. By two o&apos;clock Wednesday afternoon things had quieted down enough so we had our interview in the foyer to the Ball Room. There were the usual questions. Where were you born? In La Salle County, Ill., on March 26, 1885. Where did you go to school? Northwestern University, B.S. degree in 1906. Where did you start work? For E. J. Longyear right after leaving school. One&apos;s ability as a geologist was measured by one&apos;s ability to wield a brush hook and ax. He stayed on the job as geologist for three years and then got to thinking about the advantages of a warmer climate. The advantages stacked up favorably, so off he went to Birmingham, Ala., just about the time U.S. Steel took over the Tennessee Coal, Iron and Railroad Co.

Jan 1, 1948

By M. S. Burton, B. W. Christ, G. V. Smith

Evidence of the effects which high-angle grain boundaries and veining subgrain boundaries have on the yield phenomenon of zone-refined iron is reported. Room-temperature tensile tests on 50-mil wive at several gram sizes produced upon recrystallization at diffevent temperatures below 910C (a-y phase-transfornzatzon temperature) show that upper and lower yield stress decrease with increasing grain size. The upper yield point effectively disappears at grain sizes of 81 and 102 u in samples of this diameter. However, samples of 129 p grain size. produced during recrys-tallization at 950°C, exhibit a pronounced upper yield point and an increased lower yield stress. Possible causes of the reversal in the grain-size dependence of yielding are discussed. Veining substructure, detected with picval-HC1 etchant, but not with 2 pct nital, is formed during the a-y transformation, and is believed to account for the observed effecls. The strengthening associated with high-angle boundaries in zone-refined tron is discussed in terms of: 1) the stress dependence of slzp multiplicity, and 2) the stress dependence of dislocation emission from grain boundaries. WIDE use of transmission electron microscopy and dislocation etch-pitting techniques has led to a growing awareness of the presence of dislocation substructures in annealed pure metals. Whereas much speculation&apos;-4 has developed about the influence which subgrain structures have on the mechanical behavior of metals, particularly the yield strength, only limited experimental evidence correlating subgrain structures with lower yield strength has been presented. 2,3,5-7 It is the purpose of this note to present experimental evidence of the effects which grain boundaries and subgrain boundaries have on both the upper and lower yield strength of zone-refined iron. Effects due to high-angle boundaries formed upon recrystallization below the a-y phase transformation are compared with effects due to veining subgrain boundaries formed upon "recrystallization" above the a-y phase-transformation temperature. These effects are further compared with the reported influence 2,3,5-7 which low-angle boundaries have on the lower yield strength of bcc transition metals. EXPERIMENTAL PROCEDURE The starting material for these experiments was a 1-in.-diam zone-refined ingot prepared at Battelle Memorial Institute. Initial purification of electrolytic iron by vacuum-induction melting was improved by a floating zone-melting treatment in ultrapure hydrogen.&apos; Chemical analysis of this zone-refined iron appears in Table I. Tensile samples of 50-mil wire were prepared by rolling and drawing portions of the ingot. An intermediate recrystallization anneal at 625°C after rolling to a reduction in area of 85 pct was carried out in an evacuated Vycor capsule (10-=5 mm Hg). Further reduction in area of 91 pct was followed by recrystallization in evacuated Vycor capsules at temperatures between 600" and 950°C, see Table 111. All samples

Jan 1, 1967

By John V. Beall

Never having done it before, it took us all day and until 11 at night to select and pack for a four-day back- pack trip up Lake Chelan last month. When we were through, we couldn&apos;t lift our own pack and Sylvia&apos;s, OUT spouse&apos;s, we barely managed to budge. Nevertheless, the next morning we were at the dock to board the Laldy of the Lake for the 3 ½ -hr boat trip to Lucerne. Our dress and accouterments creating the appearance of a veritable expedition into the wilderness made a sharp contrast with our fellow passengers, a senior citizens tour group from Spokane. We had come out to Seattle for the SME Fall Meeting and were taking advantage of the occasion for a vacation trip back to Lucerne and Holden where we had lived briefly 25-years ago, and a backpack trip up Railroad Creek from Holden to the Glacier Peak country, weather permitting. No matter what you say, weather is important, and this is one of the ingredients that went into making the SME Fall Meeting and Exhibit in Seattle, September 22-24, a thoroughly delightful experience for the 700 plus persons who attended. Seattle is a beautiful city, but with late September sunshine, which we experienced, it is the best. The second ingredient, is a swinging host committee. Under the leadership of Don Anderson and Tom Van Zandt, co-chairmen, and Mrs. Cecilia Reed, Ladies Program, superb hospitality and fine arrangements were blended. Earl Beistline, from Fairbanks, organized a two-day short course on arctic operations which preceded the meeting and drew an attendance of 44. Dick Robbins, in charge of arrangements, provided Masters-at- arms for technical sessions and a presentation of the colors by the U.S. Coast Guard at the Welcoming Luncheon. Eric Cheney&apos;s field trips ranged far and wide with events both before and after the meeting. David (Jeff) Kroft, capably managed audio-visual operations with a group of students from the University of Washington. Charles Hochmuth worked long, hard and effectively before and during the meet- ing on finances. Hank Reed, managed an authentic three-ring circus as Entertainment Chairman. His activities covered two cocktail receptions for all registrants and a dinner-dance. Dolph Campbell and Joe Hackbarth provided publicity by press and TV (see p. 37-40). SME&apos;s meetings have certain characteristics and possibly not all of these are known to everyone. The first of these is the deliberate involvement of the AIME Section in the area of the meeting. Most trade shows and conventions are run 100% by a professional staff and although SME staff could also do this, it has been our experience that a more friendly and better meeting results when the local members apply their talents. Actually SME only considers a site for a meeting after it has received an invitation from a Section. The knowledge of local conditions which Section committeemen bring to a meeting is of great value.

Jan 1, 1971

Erwin S. SperRy, Bridgeport, Conn.: The analysis of refined copper is a subject of great importance, and has not received the attention it deserves. Copper metallurgists, therefore, will welcome the paper of Mr. Heath with satisfaction. The state of the art of the chemical analysis of copper has been such that consumers, if they could not afford to run any risk, have been obliged to buy copper from the smelter having the best reputation, and a specification for copper to meet certain requirements could not be drawn up by the mere giving of the chemical constituents. Mr. Heath has brought the analysis of the copper to such a state that when a specification calls for copper " equal to Lake copper " one will know immediately what percentage of the pure metal to expect. It seems to be a pretty well established fact that the copper of Lake Superior is practically free from antimony and bitmuth ; and, with the exception of arsenic, the other elements are easily separated from copper by electro-deposition in an acid solution. The authorities differ in regard to the question whether antimony is deposited with the copper in an acid solution. Classen* recommends the employment of a solution containing 10 per cent. of free nitric acid, sp.gr.1.21, and the strength of the current from 0.3 to 0.4 ampere, in order to prevent the other metals from being deposited with the copper; and for this reason, I presume, the method has been generally used. I, myself, have been accustomed to use such a solution for the analysis of copper-alloys, but have found that for such alloys only a small quantity of nitric acid is necessary, if sulphuric acid is present in sufficient amount to give the solution the required conductivity.

Jan 1, 1898

By Dix, E. H.

THE percentage of manganese used in commercial aluminum alloys is small, and yet this element is an important addition to some very valuable alloys. When used alone with commercial aluminum containing iron and silicon as impurities, the usual percentage in wrought materials is from 1 to 1.5 per cent., whereas castings may contain as much as 2 per cent. An aluminum-manganese alloy containing nominally 1.25 per cent. manganese is much used in sheet form for the manufacture of cooking utensils and other articles requiring a little greater strength and hardness than could be obtained with commercially pure aluminum. It is also used for various purposes in the form of rods, tubes and pipes. The aluminum-manganese alloys, both wrought &apos;and cast, offer excellent resistance to many kinds of corrosion attack. The U. S. Naval Gun Factory uses an aluminum alloy containing from 1 to 2 per cent. each of copper and manganese, for both castings and forgings. Manganese is also used, up to about 1 per cent., as a minor alloying .element in several of the strong aluminum alloys of the duralumin type. It is felt that the role of this element when thus used has not been fully understood, but it is believed that the results obtained in this investigation will throw additional light on the subject. The earlier work on the system aluminum-manganese was general in nature, and no detailed investigations of the relations existent in the useful aluminum-rich alloys have been reported. Guilletl1in 1902 surveyed the system, and Hendrichs2 in 1908 published an equilibrium diagram which, although based on .few data, is often used in the literature. Fragmentary work has also been done by other investigators."

Jan 1, 1927

By David P. Shoemaker, Clara B. Shoemaker

It has been shown for an important class of complex transition intermetallic compounds (a, P, R, 6, and p phases) characterized by "normal" coordination [CN12 (icosahedral), CN14, CN15, CN16/ that interatomic distances nay be calculated to a good approximation as the sum of characteristic atomic radii. Two radii, one for major ligands and one for minor ligmds, are specified for each atom, except in the case of CN12 where only a miaaor-ligand radius is specified. The same appears to be true of transition-metal phases of simpler struc-ture: Laves phases (CN12, CN16), and p-tungsten phases (CN12, CN14). In the case of known examples of the more complex phases, a simple rule is given which specifies these radii. However, only a fraction of the known examples of the simpler phases obey this rule closely. To include the latter phases the rule may be modified by considering the radii as linear functions of the weighted average of the Pauling CN12 radii of the two kinds of atonzs, with the radii weighted according to the over-all chemical composition of the alloy. With very few exceptions interatomic distances for both tlze complex and the simpler transition phases can b$ predicted with this modified rule to within 0.06A. ManY intermetallic compounds are known of composition A,By, in which A is a transition element to the left of the manganese column in the periodic table and B is a transition element in or to the right of it. Frequently the coordination numbers (CN) found in these compounds are CN12 (icosahedral), CN14, CN15, and CN16 (called "normal" coordinations by Frank and Kasperl). Well-known examples are the cubic and hexagonal Laves phases which have CN12 and CN16, and the 0-tungsten (CrsO) phases which have CN12 and CN14. In the more complicated (often ternary) phases, such as the a phase,2 the Beck phases p3 and R~, the 6 phase,5 and the p p atoms occur with CN12, CN14, CN15, and (except for a) CN16; in many cases several crystallographically independent atoms of one particular CN occur in the asymmetric unit. A large number of independent interatomic distances are found in these complicated phases, varying from 20 in the a phase to 94 in the 6 phase. These distances show a large spread; they vary, for example, from 2.358 to 3.278A in the 6 phase. In our analysis of these distances we found that in each of these compounds every atomic position can be characterized by either one or two radii. The CN12 positions are characterized by a single radius, The higher coordinated positions are characterized by two radii, namely: the CN14 positions by 4 in the direction of the twelve "5-coordinated" ligands3 (called &apos;minor" by Frank and Kasperl) and by r:, in the direction of the two "6-coordi-nated" ligands (called "major" by Frank and Kasper); the CN15 positions by r15 for the twelve minor and r:, for the three major ligands; the CN16 positions by rlE for the twelve minor and r:, for the four major ligands. We have expressed the experimentally determined interatomic distances in observational equations as the sums of the appropriate pairs of these characteristic radii and the value of these radii have been determined by the method of least Squares. Despite their wide range, the interatomic distances could then be predicted by the sums of these atomic radii with an average deviation in any one compound of 0.06A or less. The results are summarized in Table I. Inspection of the radii thus obtained shows that in the structures in Table I the radii (in A) are given to a first approximation by the simple relationship: Where CN is the coordination number (12, 14, 15, or 16), and A = 1 for major ligands and = 0 for minor ligands. The interaLomic distances can be predicted within about 0.1A by sums of these atomic radii. Another phase belonging in this group with CN12, 14, 15, and 16 is the y phase & B7, in which A is molybdenum or tungsten and B is iron or cobalt. Recently the M%C phase has been refinedE and the observed distances also agree well with those calculated with Eq. [I]. (In the original determination of the structure of W6FeV7 the F$(II)-W(II1) distance was erroneously given as 2.84A, but we have recalculated it fro? the published parameters and found it to b? 2.57i4, in good agreement with the value of 2.6A predicted with Eq. [I.].) Many binary transition alloys are known to crystallize with the simpler structures having "nor-

Jan 1, 1964

Institute of Metals Division PAUL D MERICA, Chairman ZAY JEFFRIES, Vice-chairman W M CORSE. Secretary General Committee ROBERT J ANDERSON H C JENNISON L W SPRING WILLIAM K FRANK DAVID LEVINGER R L SUHL J R FREEMAN, JR. PAUL McKINNEY R F WOOD STANISLAUS SKOWRONSKI

Jan 1, 1923

Discussion of the paper of G. K. Burgess and J. J. Crowe, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 82, October, 1913, pp. 2537 to 2591. HENRY M. Howe, New York, N. Y. :-I think we can hardly rate the importance of the entry of the Bureau of Standards into our field. There is no body in the world that is better fitted to undertake this work than that Bureau, and it is work which really calls for the aid of some national organization. The skill and care with which this work has been done speaks for itself. It is very striking that within a very few months the distinguished English investigator, Professor Carpenter, of whom I spoke before, thought that he had disproved the existence of beta iron by proving that the A2 retardation which Professor Burgess has now demonstrated did not occur. Dr. Burgess&apos;s demonstration of the existence of. this retardation makes the existence of beta iron very probable, in my opinion. Osmond used to call beta iron " decipuum." You knew of its existence as you know of the existence of certain planets, only by the perturbation which it caused. Certain phenomena could not be explained, except by assuming the existence of a third allotropic form, beta iron. The evidence that you got was always evasive and susceptible of other explanations, except that which we have to-day, which it seems to me is not capable of other explanation. Professor Carpenter proceeded in the same way that Dr. Burgess has, by taking the heating and cooling curves of exceedingly pure iron, and thought that he had shown that there was no thermal change, no absorption or evolution of heat at the supposed A2 point, and hence that the A2 point did not exist. This he did by a piece of reasoning which I think seems to most of us rather surprising. That is to say, if of ten witnesses, three have seen a thing and seven have not, the evidence of the seven who have not is set aside, and that of the three who have seen stands. In Dr. Carpenter&apos;s own experiments under certain conditions he found the A2 change, the heat evolution., under certain others he did not. That is like the three witnesses who saw and the seven who did not see. You can arrange your test so that this change will not become visible or so that it is masked. But though an existent change can be masked a non-existent one cannot be shown. So that the reasoning seemed to me wholly fallacious.

Jan 12, 1913

By L. R. MacLead

Delivery of tailing to any part of the area by gravity from the ridge was found practicable. Experiments with asbestos-cement pipe proved it possible to use level pipe across the dams if it is fed through an inclined section in which pressure could be developed. Use of pipe to transfer the tailing to the dams was not favored because of the possibility that choking might occur. Metal flume was not believed to have sufficient wear resistance on this material and wooden flume would not withstand damage by the weather so well- Flume -action made- of 26-in diameter asbestos-cement pipe, split before curing and molded to a specified cross section, were finally approved. The flume is connected to the 24-in. diameter tail in distribution pipe by heavy concrete lateral launders. Cascades of horizontal and vertical pipe sections are used at the top of the pressure leg where scouring by high-velocity flow of tailing might occur.

Jan 1, 1942

By B. S. Tani, R. V. Schablaske, M. G. Chasanov

In the Ti-Cd system two intermediate phases, TiCd and Ti Cd, have been found and characterized by X-ray diffraction powder techniques. An earlier reference&apos; had reported the existence of the compound Tisd. No structural details, however, were given nor was there any indication of the possible existence of other binary compounds. Studies of the solubility of titanium in liquid cadmium2 led to the discovery of both TiCd and Tisd. The solid phase in equilibrium with saturated solutions of titanium in liquid cadmium at temperatures below 620°C is TiCd, whereas TizCd is the equilibrium solid phase above 620°C. Both thermal analysis and X-ray studies show that a peritectic reaction between the y phase (~isd) and cadmium to form the 6 phase (Ti Cd) occurs at 620°C. X-ray diffraction powder photographs of material isolated from the ingots used in the solubility measurements as well as material prepared by a direct heat of the appropriate stoichiometric amounts of titanium and cadmium can be indexed on the basis of a tetragonal unit cell with a = 2.904 ± 0.002A, co = 8.954 * 0.004A, c/a = 3.083. No variation of lattice parameters indicative of a range of composition is evident. With four atoms in the unit cell the calculated density of the intermetallic is 7.05 g per cm3; the observed value is 7.07 g per cm3. The TiCd lattice is primitive as indicated by the fact that there are no systematic absences among hkl reflections. The absence of all hko reflections for which h + k = 2n + 1 is also evident. This systematic absence indicates the following two space groups, C\h — P4/n and D&~4/nmm; both groups, however, have the same two- and four-fold positions. Stoichiometry, symmetry and space group indicate two likely structure types. They are the PbO-litharge3 (B10) type and the Ti CU (B11) type. Spatial considerations favor the B11 structure with atoms placed in the following positions: 2Ti (c) 0, 1/2, Z; l/2, 0, Z 2Cd(c) 0, 1/2, Z; 1/2, 0, Z The TiCd structure may be summarily described as a layered structure in which double cadmium layers alternate with double titanium layers along the c-axis. The best agreement between calculated and observed intensities is obtained for the values ZTi = 0.608 and ZCd = 0.130. Calculated and observed powder intensities as well as other pertinent powder data are recorded in Table I. Interatomic distances for the proposed structure are recorded in Table II and are to be compared with the distances of closest approach for titanium and cad-

Jan 1, 1962

By C. S. Matthews, H. C. Lefkovits

The performance of depletion-type reservoirs at the stage in which the gas is at such low pressure that gravity is essentially the sole driving force has been investigated both theoretically and by use of scaled models. A simple theory is developed which completely explains the scaled model experiments. It also agrees with some field data. When the range of production rates to be considered is less than 25, the theory predicts that the production rate decline curve for homogeneous reservoirs in which there is a free surface will be of the hyperbolic type with n = 2: The theory gives a physical significance to the parameter y. INTRODUCTION This investigation was undertaken to determine a method for prediction of performance of reservoirs where gravity is the sole driving agent. Depletion-type reservoirs fall into this category after the pressure has fallen to some low value. Some examples of this type are found at Healdton (&apos;Oklahoma), Oklahoma City (Oklahoma), Midway-Sunset (California), and East Coalinga (California). Generally the production rate per unit thickness is quite low in such reservoirs, with the conse- quence that this stage is sometimes called the stripper stage. However, per well production rates may be of the order of 50 B/D because of the considerable sand thickness open in some of the reservoirs. In the past, predictions of behavior of such reservoirs have been based on empirical extrapolation of the rate of production to the economic limit. Difficulties arise when new wells are drilled in the field or when production is artificially curtailed, since in such cases the decline rate of individual wells or leases changes and no clear trend can be detected. It was hoped that the present study would lead to improved methods for evaluation of such reservoirs. The study was initiated by building a scaled model for a particular field and by running a number of experiments on this model. Later a simple theory was developed which explained the laboratory results completely. The theory led, as shown below, to a hyperbolic-type decline equation which had been used previously&apos; in a completely empirical manner. THEORY The General Case The problem to be treated here is the following: We are given a homogeneous cylindrical porous reservoir with exterior radius r, wellbore radius r., and height h,, containing, from the bottom up to a height hit oil, some gas, and interstitial water (see Fig. 1 A). The portion of the reservoir between K, and h, is filled with gas at low pressure, with residual oil, and with interstitial water. If at a time t = 0, the level of the oil in the wellbore is lowered to a height h,, what is the production rate from the reservoir at a time to The configuration within the reservoir at some instant

Jan 1, 1957

By J. R. Cahoon, W. V. Youdelis

In a recent publication by Flemings and Nereo, equations for the calculation of the solute distribution in castings were developed, and the solute distributions for unidirectionally solidified A1-4.5 pct Cu ingots cast under various thermal conditions were calculated. The equations derived by Flemings and Nereo for the dendrite "expansion" and "steady-state" zones are essentially equivalent to those previously published by Kirkaldy and Youdelis, 16 for, although the flow velocity cooling rate, and temperature gradients appear in the fundamental differential equations, calculation of the solute distribution requires that the above be explicitly related to the assumed or measured solid-liquid mass distributions during solidification. In the treatment of Kirkaldy and Y-oudelis the mass distributions are simply assumed or measured without any prior and explicit association of the mass distributions to a velocity parameter. The treatment of Flemings and Nereo permits solidification conditions more complicated than the simple unidirectional case to be considered (although in principle the treatment of Kirkaldy and Youdelis could also be extended to include the more general solidification case); however, we note some limitations in the treatment of Flemings and Nereo, and the purpose of this discussion is to point these out and also to indicate those points of similarity in the mass distribution models used which make the two treatments equivalent. Both the Kirkaldy-Youdelis and Flemings-Nereo treatments consider a zone of dendrite "expansion" followed by a "steady-state" zone. However, Flemings and Nereo have failed to consider a zone of "collapse" which begins at the base of the first dendrites to reach the top of the ingot. The omission of this zone of "collapse" results in too high a value for the solute concentration in the latter portion of the ingot to solidify and the conservation of total solute is not possible. In the zone of "collapse" the solute concentration rapidly decreases, which may be accounted for as follows: consider a mushy zone of length X,, shown schematically in Fig. 11 (a), which develops at the chill face and then moves as a steady-state configuration along the length of a solidifying ingot. The solute distribution in this zone, when it first attains the steady state, is shown qualitatively in Fig. 11(b). The segregation is positive (above Co) in the region ab because this region contains primary dendritic solid, ranging from kco to kcE in composition (where k is the partition coefficient and CE is the composition of the eutectic liquid), and liquid metal near eutectic composition. The segregation is negative (below Co) in the region bc because it contains primary dendritic solid only slightly above kco in average composition and liquid metal only slightly above Co in composition. As the zone X, moves as a steady state

Jan 1, 1969

[Executive HERBERT G. MOULTON, Chairman WILLIAM WRAITH, Vice-Chairman ,PAUL D. MERICA W. M. PEIRCE H. Y. WALKER Finance H. T. HAMILTON, Chairman ERLE V. DAVELER HENRY KRUMB Admissions FELIX E. WORMSER, Chairman GEORGE D. BARRON, Vice-Chairman CHESTER A. FULTON PHILIP KRAFT EDWARD MEAGHER Alternates P. B. BUCKY LLOYD C. GIBSON F. T. SISCO]

Jan 1, 1940

By William B. Plank

NEVER before have so many men chosen the mineral technology field for their college training. In the college year 1936-&apos;37, 7190 such students were enrolled in the 53 schools of the United States. My last study of the mineral technology schools of the United States and Canada was made for the year -1934-&apos;35, and the current study, as the previous one was made for the A.I.M.E. under the auspices of the Division of Mineral Industry Education. Altogether, four studies of enrollment have been made. The first three were for successive college years beginning with 1932-&apos;33. This present one covers a two-year period, for the purpose of these studies may he served satisfactorily if they are made biannually. The data on the schools were collected in the same way as for former studies, &apos;namely, by questionnaire, dated in this case Nov. 18, 1936. The figures reported are therefore comparable with those of former cars.

Jan 1, 1937

By H. Shaw

In the author&apos;s previous paper an attempt was made to analyze in detail the gravitational effects arising from certain subterranean anomalies of simple form, and extending to infinity in three directions. As a result of this critical examination, certain features—which were considered to be characteristic of the anomalies under investigation—were disclosed, a close observance of which enables a complete interpretation to be reached. The most simple case was first considered; viz., that of a heavy horizontal plate, bounded above and below by horizontal planes, and extending to infinity on one side of a vertical plane containing the y axis, in the three directions + y, —y, and +x. After this, the investigation was extended to the case of a similar infinite horizontal block having an inclined face. In each case the form and behavior of the gradient curve and the curve of differential curvature were analyzed, and entirely distinct interpretations were put forward, based upon (1) the gradient, (2) the differential curvature and (3) a comparison of these two quantities. In continuation of the previous work, and as a preliminary to further analysis of more complex structures, certain factors will now be examined which characterize (1) the simple infinite vertical block and (2) an infinite block which is inclined to the vertical, formations which are of considerable practical interest, being typical of important. geological structures—intru-sive dikes, lodes, veins, etc.—and because, even though in nature these may be irregular, valuable guides to a more complete interpretation are obtained by assuming, as a first approximation, that they have the simple characteristics to be studied hereafter. In the previous paper certain preliminary assumptions were made in order to render the resulting deductions universally applicable and entirely independent of the particular scale employed. Consideration was limited to homogeneous deposits of unit positive effective density (and this condition is retained in the present investigation), so that in the case of

Jan 1, 1932

By W. C. PAGE

ALL mine ore here must be concentrated before shipment, which involves selective flotation. Three products are made: lead, zinc, and pyrite concentrates. The equipment and practice are so well outlined in the accompanying flow sheet that only a few amplifying remarks are necessary. After crushing at the mine to approximately 4 in., the ore is carried by aerial tram about 4 1/2, mi. to the mill. From 1800 to 2000 metric tons per day, excluding Sundays, is thus transported. At the mill, the buckets are hand-tipped into the bins. After crushing to pass a ¼ -in. square opening, the ore may be stored in reserve crushed-ore bins or ball-mill feed bins as desired. Total bin capacity at the mill is about 4000 metric tons. The concentrator is arranged in three independent grinding sections, each fed from its own storage bin. Grinding operations follow standard practice, with ball mills in single-stage closed circuit with classifiers, the overflow from which is delivered to the lead circuit rougher flotation machines,

Jan 1, 1936