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By F. C. Frischknecht

Most early development and application of electromagnetic prospecting methods took place in Scandinavia, where geological conditions favor their use. In other parts of the world these methods have aroused cycles of interest, but in Scandinavia they have been used continuously and successfully since the 1920's. Electromagnetic methods may be classified into two general groups. One group includes methods in which the source of the electromagnetic field remains stationary while the receivers are moved about to explore the area. The other includes procedures in which the energizing and receiving systems are moved together. Other classifications could be based on the size of the energizing source, the particular components of the electromagnetic field which are measured, or the mode of transporting the equipment. The difference between fixed-source and moving-source methods, however, is of such great fundamental importance that it will be emphasized in this discussion. FIXED-SOURCE METHODS Essentially, a fixed-source method consists of the measurement of electromagnetic fields about the source. The mutual coupling between the source and the earth is constant, but the mutual coupling between the receiver and the earth (unless the earth is homogeneous) and also between the source and the receiver changes at each station. The results are usually normalized by relating the field data to the calculated free space or primary field. Turam and Radio Reference Signal Methods: The turam or two-frame* (see Fig. 1A) is probably * Turam means two-coil. the most common fixed-source method. The energizing source is an insulated cable grounded at both ends or formed into a large rectangular loop. Measurements are taken along a traverse at 5 to 50-meter intervals using two small receiving coils, the lagging coil being placed at the position previously occupied by the leading coil. The complex ratio (i.e., inphase and out-of-phase ratios) of the voltages induced in the two coils is measured. Operating frequency range is about 100 to 800 cps. In a typical turam survey a straight, grounded cable several kilometers long is laid out parallel to the probable strike of the ore deposits or conducting strata being sought. An area extending 1 or 2 km on each side of the cable, and within 1 or 2 km of the ends of the cable, is surveyed. Measurements are made at stations 5 to 25 m apart along traverses perpendicular to the cable. Measurements may be made along lines parallel to the cable to serve as base lines for the traverses or for other special purposes. Commonly the receiving coils are oriented with their planes horizontal so that only the vertical component of the field is measured. If additional information is required, one of the hori- zontal components may also be measured by orienting the coils with their planes vertical. In a modified turam technique developed recently for both ground and airborne measurements (Fig. 1B) the amplitude of the complex voltage induced in a single receiving coil is measured and its phase compared with that of a reference signal transmitted from the energizing system by a radio frequency carrier. Thus the un-normalized field is obtained directly, whereas with the turam method it is obtained by calculation from the ratios. The turam method and its modifications have a greater working depth than the other electromagnetic procedures used in ore prospecting. Under favorable conditions conductors have been located at depths of 200 to 300 m. A modified turam method with one of the electrodes grounded in the upper end of a plunging orebody was used to follow the extension of this body to a depth of 200 m beneath a layer of conducting schists. Straight grounded cables are usually preferred to insulated loops because they are easier to lay out and because they often make the method more sensitive. The greater sensitivity of a grounded cable is a result of ground return currents which may flow in the orebodies in addition to the eddy currents caused by induction from the current in the cable. Anomalies in the vertical field due to eddy currents are characterized by a correspondence between high values for the inphase component and positive out-of-phase components and/or low values for the inphase component and negative out-of-phase components. Also the inphase component may approach zero, but it does not become negative. In very long continuous conductors that are parallel to a grounded cable the effect of ground return currents may far exceed the effect of eddy currents. These ground return currents cause a lack of correspondence between the inphase and out-of-phase components and may cause negative inphase or anti-phase components. It becomes difficult to carry out the measurements and often difficult to interpret the results. Such results immediately suggest the presence of graphitic strata, however, since ore deposits are rarely extensive enough to accumulate sufficient ground return current to cause these results. A cable laid out perpendicular to the strike or an insulated loop is sometimes used in areas where graphitic schists and slates are present. Anomalies are then completely or almost entirely due to eddy currents and are easier to interpret. The measured voltage ratios are normalized by either subtracting or dividing by normal field ratios calculated from free space considerations. The normalized ratios are then plotted as individual profiles. When significant anomalies occur in the ratio measurements, the actual normalized fields are calculated by beginning with a measured or an assumed value for the field at a point near the cable and successively multiplying this value by the normalized ratios. There is a similarity between this process and a numerical integration of the ratio curve. Conversely, in many respects the ratio curve is similar to the first derivative of the field curve.

Jan 1, 1960

By William P. Blake

In another paper I have described in general the close association of zinc-blende and iron pyrites in the ore-deposits of southwest Wis consin. These two minerals generally occur together at the same horizon, a sheet of one being overlain by a sheet of the other; and also the pyrites is disseminated through the blende to such a degree that the latter is rendered comparatively worthless for the produc tion of spelter. Ordinarily the pyrites, which is mostly the trimetric marcasite variety, occurs in about equal quantity with the blende and is separated by hand-culliug and chipping; but there are large de posits where the ores are so closely mixed that they can neither be separated by culling nor by any mechanical method. The specific gravity of the two minerals is so nearly the same that attempts often made to effect even a partial separation by jigging have proved un. successful. The smelters of zinc-ores in the Mississippi valley will not take ores which carry more than 7 per cent. of iron; and it is therefore necessary to cull the massive ('jack" with great care and at consid erable expense, in order to bring it up to the market-standard of purity. The results of trials to effect a separation of blende and pyrites in other regions have been equally unsatisfactory. The literature of this branch of metallurgy abounds in examples. In Wisconsin efforts have been made in the past to " burn " the mixed ores in heaps, in order to soften or destroy the pyrites, and facilitate its separation from the massive blende. The same method has also been resorted to when galenite is mixed through the substance of the blende, for the purpose of disintegrating the ore, so that it could be separated by jigging. The custom was to pile the ore and the fuel together. As might have been expected, the results were far from satisfactory. As is usual in heap-roast ing, some portions of the ore were overheated and decomposed; zinc was lost by volatilization; the galenite in some portions was

Jan 1, 1894

By Dever Ashmead

ANTHRACITE was first mined in the Wyoming Valley and sold as an article of commerce in 1808. As some preparation has always been necessary to make it ready to burn, the preparation of anthracite must date back over a hundred years. Two vital factors have determined to a large extent the degree and method of anthracite preparation. These are, first, the character of the beds worked and the methods by which they were mined and, second, the equipment used and practices followed in the burning of the coal. It is not the intention here to go deeply into these phases of preparation as a paper of no mean length could be prepared on the history of either. Rather, the intention here is to point out the main considerations and to show the influence they have exerted on the preparation of anthracite. MINING METHODS AND THEIR RELATION TO PREPARATION In the beginning f the nineteenth century, the coal beds were virgin with the possible exception of some outcroppings that had been worked, to a slight extent, by the Indians. It is known that the American aborigines had a knowledge of the use of this fuel, because when the Wyoming Valley was purchased from them, in 1754, they mentioned the fact that, by selling the land, they would lose their coal.

Jan 9, 1921

By W. F. Boericke

INTRODUCTION THE Wisconsin zinc district, or the Upper Mississippi lead. and zinc district as it is also termed, lies in the southwestern corner of Wisconsin, and embraces adjacent portions of Illinois and Iowa. It includes Iowa, Grant, and Lafayette counties in Wisconsin, and Jo Davies county in Illinois. In Iowa, Dubuque formerly produced considerable lead, but there has been little mining there in recent years. The map, Fig. 1, shows the entire district, with roads, railways, streams, and the various towns, or "camps," around Which the mines. are clustered. The hatchwork indicates the areas iii which lead and zinc have been mined. The district is about 60 mi. (96 km.) north and south and about 40 mi. (64 km.) east and west. Not all of the territory is mineral bearing, and there are considerable areas that are believed to be barren. The grouping of the mines is patchy and irregular, though certain broad zones of mineralization extend almost the full width of the district, as from Mineral Point west through Mifflin and Livingston, and from Shullsburg west through New Diggings and Hazel Green. It is worth noting that the best mines of the district have, to date, been found within 10 mi. east or west of the fourth principal meridian line, thus lying within a long, narrow, north-and-south belt extending the length of the district. In a field as large as the Wisconsin, which has only within com-paratively recent time been worked intensively for zinc, the. chances are good for, opening new and important orebodies in parts of the district not yet, or insufficiently, prospected. However, the prospecting has been most successful around, or adjacent to, the old lead diggings of nearly a century ago, and the camps that were well known then are still centers of activity. In their order of importance they are: New Diggings, Benton, Mifflin-Livingston, Galena, Linden, Hazel Green, Shullsburg, and Highland.

Jan 8, 1919

By John A. Putnam, Morrough P. O’Brien

DATA on the physical and thermodynamic properties of hydrocarbons have been made available in recent years but the formal method of applying these data to flow in porous media appears not to have been fully developed. By making usual thermodynamic assumptions and employing existing data on permeability to two-phase flow, Darcy's law may be applied to obtain the flow characteristics for representative combinations of flowing medium and geometry. The numerical examples presented herein are based on hydrocarbons for which complete physical and thermodynamic data are available under equilibrium conditions. INTRODUCTION Thermodynamic data are obtained in the laboratory under equilibrium conditions and their application requires the assumption that equilibrium also exists during flow. This assumption is at least usual in engineering analyses, though not easily justified in many instances, and will be followed here. In regard to hydrocarbons, laboratory experience in determining the pressure-volume-temperature relationships indicates that gas-liquid mixtures must often be stirred vigorously for periods of 15 to 20 min. before reaching equilibrium. On the other hand, boiling and condensation are known to occur on solid surfaces and the large surface exposed to the flowing substance by a porous medium may bring about rapid approach to equilibrium. For the purpose of providing at least a guide to experimentation and a standard for later comparison with experimental results, it will be assumed that the phases present in cross sections perpendicular to the direction of flow are in thermodynamic equilibrium. Another assumption usually made in the solution of problems of flow in porous media is that the fluid remains at a constant temperature; i.e., isothermal flow. This assumption is arrived at by considering the porous medium and surroundings to be an infinite heat source and the rate of heat flow to be infinite at a boiling front. Its validity depends in large measure upon the character of flow, the number of components, and the physical and thermodynamic properties of the fluid. However, the assumption of isothermal flow represents a limiting case. The other limit can be represented by the assumption that the fluid is thermally isolated; i.e., irreversible adiabatic. The thermodynamic process characterizing the actual flow of a given fluid system probably lies somewhere between these two limiting cases and might be thought of as a flow system in which the confining walls are maintained at a constant temperature. For isothermal flow the solid material of the porous media is considered as the infinite heat source capable, without loss in temperature, of giving up heat to the fluid as the latter tends to cool by expansion. For the thermally isolated system, the solid material is considered to give up no heat to the fluid. In the intermediate case the impervious walls confining the porous media are at constant temperature from which heat is transferred along various paths, solid and fluid, throughout the porous media. It would appear that an actual petroleum-

Jan 1, 1941

By AMY F. JENNINGS

TO give a concise history of the Woman's Auxiliary of the A. I. M. E. is a difficult task and much interesting information must needs be omitted. The organization has grown and evolved so much from its early simple beginning that it seems best to adopt the technique of some of our modern novelists and begin with the latest development. As the headquarters of the A. I. M. E. is in New York, it follows that the Woman's Auxiliary to the A. I. M. E. necessarily has also its central office and government there. The affairs of the organization are administered by a duly-elected president and five vice- presidents, a treasurer, recording secretary, and corresponding secretary and a board of directors, the personnel of which includes each chairman of a section or an elected or nominated representative who is able to attend the monthly meetings of the board and correspond with the section for which she acts, and the chairmen of the five standing national committees, i. e. Educational Fund, Library, Emergency, Membership and Hospitality. The chairmen of these committees are all responsible to the president and board of directors and their activities must be indorsed with their approval.

Jan 1, 1929

In the Philippines, where distances are spoken of in terms off fight time, the Sipalay copper mines are two flight hours southeast of Manila on the island of Negros. After landing at the airport in Bacolod, it is then 170 km (106 milers) by surface transportation to Marinduque Mining and Industrial Corp.'s expanding copper operation. While copper deposits were discovered in the area in 1936-and one mine, the Binulig, began operations soon after-it wasn't until 1956 that stripping at Sipalay and construction of a 4000-t/d (4400-stpd) mill began. The mill went into operation in May 1957, and the first shipment of copper concentrate was made three months later.

Jan 8, 1978

By A. U. Seybolt, V. A. Phillips

Binary iron alloys containing 1 pct of Al, Cr, Mn, Mo, Si, Ti, or V, and 0.4 pct C, 1 pct Cr steels with and without 1.2 pct A1 or 2.0 pct Ti additions, were ion-nilrided at 550° to 600° in N-H mixtures. Nitriding increased the inicrohardne ss of all the binary alloys except those containing manganese or molybdenutn, and also hardened the heat-treated steels if aluminum or titanium urns present. Transmission electron microscopy revealed particle formation in all casts where hardening occurred. Electron diffraction gare positive identifications for ALN, CrN, and a, Si3N4 in the binary alloys, and AlN and CrN in the aluminum- cold chromium-bearing steels, respectil&apos;uly. Cubic VN with a, = 4.13A was tentatively identified. Particles, apparently of CrN, also formed in the base steel but did not increase the hardness very much. Chromium and vanadium formed nitride platelets on {001}° matrix planes, while titanium gave clusters <15A diam. Aluminum nitride precipitated at grain and subgrain boundaries, and within the grains. Silicon gave profuse precipitates of several Morphologies at grain boundaries and cubical particles within the grains. No effect of the alloy carbides on nitride precipitation was observed in the heat-treated steels. THE nitriding of steel has been a well-established commercial process for about 40 years, but in spite of this comparatively long period of use there have been few studies aimed at understanding the process. Most studies, like the early but very competent work of Jones and organ&apos; and nones.&apos; were concerned with establishing the pertinent engineering variables of steel composition, gas composition, temperature, and time. As far as the present authors are aware, there have been no studies of the composition, size, shape, or distribution of the nitrides formed in the nitriding of steel. Noren and Kindbom3 did, however, examine a few nitrided steels by surface replica electron microscopy, and were able to show the presence of car-bonitrides and AlN and TiN nitrides. pitsch4,5 and Hrivnak6 examined nitrided pure iron by transmission electron microscopy. Baird7 found manganese nitrides in Fe-1.6 pct Mn when nitrided at 650°C, using the same technique. In the present work, emphasis was placed on transmission electron microscopy because of its inherently better resolution, using principally binary alloys of iron containing 1 pct of alloying element. In addition, a few simple 0.4 pct C steel compositions were examined to investigate possible carbonitride formation. It was not anticipated that all of the added elements would form nitrides under the conditions used, but it was considered desirable to obtain direct experimental evidence on this point. It would be considerably easier to ascertain the presence of alloy nitrides by examining appropriate binary alloys in preference to relatively complex steels. The work reported here could have been done using orthodox ammonia-nitriding procedures, but an operating ion-nitriding equipment was available, and was therefore used for specimen preparation. EXPERIMENTAL DETAILS 1) Materials. Binary alloys were made up from vacuum-melted electrolytic iron with 1 wt pct additions of Cr, Ti, V, Al, Mn, Mo, and Si of about 99.9 pct purity. In addition, three steels were similarly made up—a basis steel with 1 wt pct Cr and 0.4 wt pct C and two steels with further additions of 1.2 wt pct A1 or 2.0 wt pct Ti, respectively. The materials were vacuum-melted and cast as 11-lb heats into tapered square molds of about 2 by 2 in. average cross section. The castings were forged and hot-rolled to 11/4 in. rounds. Discs of 4 in. thickness by about 1 in. diam were machined from the rods. Some of these discs were hot-forged and hot-rolled to about 0.020 in. thick, sand-blasted, and then cold-rolled to about 0.003 in. thick. At this point, the surface was cleaned by light etching with HC1, then washed, dried, and vapor-degreased prior to nitriding. 2) Ion-Nitriding Procedure. The type of ion-nitriding equipment used here is similar to that described by Jones and Martin.8 Briefly, a mixture of nitrogen and hydrogen at 5 mm total pressure is placed in a vacuum chamber with a dc potential of 450 to 500 v applied between the work (cathode) and the grounded metal vacuum enclosure (anode). Nitrogen ions are accelerated to the work where a thin layer of Fe4N forms on the surface and thus sets up a nitrogen concentration gradient. This causes nitrogen atoms to diffuse into the surface layers of the alloy forming a finely divided dispersion of alloy nitrides, causing hardening of the surface. In the work to be reported here. the nitriding was carried out at 550° to 600°C to be consistent with commercial nitriding practice. The temperatures cited are those measured by a thermocouple located under a platform on which the work was sitting. Except where otherwise stated, the mixture used in nitriding the binary alloys contained -2.0 pct N, balance hydrogen. The nitrogen concentration in the nitriding gas mixture used for the binary alloys was purposely kept lower than normally used in nitriding steels. 10 to 20 pct, in order to minimize Fe4N formation. In this way only the alloy nitrides would be present as a second phase. However, in the case of steels which would contain a- carbide phase along with as

Jan 1, 1969

By G. Barbery

Since the original paper, two methods have been introduced to compute the parameters of the three parameter size distribution equation: [ ] Both of them are based on graphical means, which are time-consuming and of little statistical significance. A program has been developed, using the Gauss-Newton method to compute by nonlinear regression analysis the parameters of the equation. Although the method is quite general in curve-fitting applications, it does not appear to be used in the field of size analysis, and a brief description is given. As applied here, the Gauss-Newton method involves the minimization of the least squares: [ ] where n is the number of sieves used. The second member of Eq. 2 can be approximated by a multiple Taylor&apos;s series expansion of first order about a starting value [ ] The minimization of Q (r,s,Xo) means: [ ] Putting Eq. 3 into Eq. 2 and differentiating, we obtain a system of equations which can be represented in matrix symbolism (box) The system can be solved for: [ ] and the operations repeated with new values: [ ] The starting values for r and s are taken as 1, for Xo, a value higher than the maximum sieve opening value. Applied to the data given by Herbst 5,6 for batch grinding of 7 X 9 mesh dolomite, the parameters given in Table 1 were obtained. The discussion of the significance of the residual sum of squares is a difficult subject in multiple nonlinear

Jan 1, 1972

By Max Y. Seaton

THE scope of this paper will be limited to finished materials that contain a large preponderance (around 80 per cent or more) of magnesium oxide. The large and commercially important production of refractory dolomite and modified dolomites is not discussed here, and the production of magnesium basic carbonate for use as a heat insulator is barely mentioned. The discussion is confined mainly to magnesias produced in comparatively great quantity by direct processing of naturally occurring raw materials and hence excludes secondary or highly purified products such as pharmaceutical products or U.S.P. light and heavy calcined magnesias of commerce. NOMENCLATURE The nomenclature of the magnesia products that will be discussed is somewhat confusing, in that it is customary in the trade to designate as "calcined magnesite" the materials that result from the calcining of magnesite to temperatures that remove the contained carbon dioxide. The finished product, therefore, is not magnesite at all but simply a more or less pure magnesium oxide or magnesia. Furthermore, partly for statistical and partly for commercial reasons, it has been customary, during recent years, to classify as "calcined magnesite" products that result from the heat-treatment of magnesium hydroxide precipitated from magnesium-containing brines; products that, obviously, have no relationship whatever to magnesite. In the listing of magnesia-containing materials, tonnages of which are regularly reported by the Bureau of Mines, reports ordinarily are made under two headings: "caustic calcined" magnesite, in which all of the varieties of products treated at relatively low temperatures are lumped; and "dead-burned" magnesite, in which are included both high-purity and low-purity, and particularly both high-iron and low-iron, materials that have been so heat-treated that the magnesium oxide occurs predominantly as crystalline periclase-materials used almost entirely for refractory purposes. In 1940 the apparent domestic consumption of "caustic calcined" magnesite was approximately 17,000 tons, about 95 per cent of which was produced in this country. The apparent consumption of "dead-burned" magnesite was approximately 172,000 tons, some 82 per cent of which was domestically produced. In both total quantity and percentage of material produced within the United States, these figures are record highs for many years past. UTILIZATION As indicated by these figures, the major tonnage outlet for magnesia is the refractories industry, in which magnesia is employed principally in three ways: (I) as dead-burned grain magnesite for the construction and maintenance of the hearths or bottoms of basic open-hearth furnaces; (2) in the form of refractory magnesite bricks and shapes; and (3) as a chemical

Jan 1, 1942

By M. Kaufman, A. E. Palty

The phase structure and aging characteristics of two nickel-base alloys, Inconel 718 and 702, were investigated. Wrought and cast Inconel 718 showed ArisCb as the major hardening phase, as well as ture was positively identified. Inconel 702 had Ni3Al as the major hardening phase, as well as Cr7C3-of the phase amounts with temperature was determined. 1 HE value of phase structure and aging rate information in the utilization of alloys has been well established. As part of a continuing program, the results obtained on two nickel-base alloys, hconel 718 and Inconel 702, are presented here. Inconel 718 is a relatively new alloy considered for application in both sheet and cast form. Its novelty lies in the use of high columbium tantalum levels in a Ni-Cr-Fe base. No previous work on this type of alloy has been reported in the literature. Inconel 702 is being used now as an oxidation-resistant sheet alloy. Occasional fabrication problems spurred work on its basic structural behavior. The composition of 702 is essentially nichrome plus aluminum and titanium for strengthening and added oxidation resistance. This puts it in the basic class of other nickel-base alloys which have already been studied. The two alloys will be treated separately. INCONEL 718 Phase Study Methods. The phases present after the various conditions investigated were determined by X-ray diffraction analysis of two different elec-trolytically extracted residues and microscopic examination. The extraction methods, using 10 pct HC1 in alcohol and 10 pct H3PO, in water and the X-ray technique have been described previously.&apos; The effect of temperature on the phase behavior was studied on sheet material using the following heat treatments: 2250°F, 2 hr, ice brine quench 1300 100 hr, water quench 2250°F, 2 hr, ice brine quench 1400°, 100 hr, water quench 2250°F, 2 hr, ice brine quench 1500°F, 100 hr, water quench 2250o 2 hr, ice brine quench 1700°F, 48 hr, water quench 2250°F, 2 hr, ice brine quench 1850°, 24 hr, water quench 2250°, 2 hr, ice brine quench 2000°F, 6 hr, water quench The high solution temperature was an attempt to dissolve as many phases as possible without causing melting. Aging exposures were made longer than normal heat treating times in order to approach equilibrium conditions more closely. Cast material was examined only in the as-cast condition and with the normal heat treatment (1700°F, 1 hr, air cool 1325oF, 16 hr,air cool). Materials. The full phase study was performed on sheet specimens approximately 1/2 in. by 2 in. by 1/16 in. The cast pieces were cut from the gating system of a vacuum-cast test piece. An all weld-metal specimen was made by running many weld beads on the sheet using filler made from the sheared edges of the sheet. All external contamination was removed by belt-sanding followed by an electro-polishing treatment. The typical composition of wrought Inco 718 is as follows: The alloy is air-melted. Cast hco 718 may have higher molybdenum. Due to the expectation of finding a Ni-Cb phase (Ni, Cb) for which no X-ray diffraction pattern was available in the ASTM Index, a special 5 Ib heat to the stoichiometric composition of this intermetallic

Jan 1, 1962

By GUY C. RIDDELL

ZINC, manganese, and aluminum received attention at the two nonferrous metallurgy sessions at the Annual Meeting. L.P. Davidson, general superintendent of the rebuilt Monsanto zinc plant, described its operation, which reflects Polish practice and is really a combination of electrolytic, Waelz, and retort procedure. Briefly, it embraces leaching of roasted concentrate with sulphuric acid, electrolysis of sulphate solution using Tainton lead-silver anodes with ?goulac? added to the electrolyte, treatment of tailing in Waelz kilns, and retorting of the recovered zinc oxide, casting furnace dross and residues. Recovery is good, equipment and maintenance costs low. Ferrate zinc that might be lost in the electrolytic process appears to be recovered as oxide in the Waelz treatment.

Jan 1, 1942

With the signing of the armistice on Nov. 11, the direction of the main concentration of effort of the United States was changed. In order to win the war, all industrial efforts had to be organized and centralized. With the war won and peace in sight, this centralization of effort stopped and the full play of individual initiative was allowed to resume its sway in the community. During this period of reversal of direction of effort, there was a natural loss of momentum and the United States, as well as the rest of the world, is in for a period of readjustment. The immense progress that was made in one direction under the stress of the necessities of war, which focused the energies of a nation in one direction, is an outstanding example of what can be accomplished if a community with many varying interests can be united on one objective which it desires to attain. The realization that the fusing of many interests into one stream of effort is difficult should not prevent us from taking the long view ahead that is necessary in order to be able to measure the progress made. If we don&apos;t have a mountain peak to guide us, we are very likely to run in circles in the plain without reaching the goal to which we strive. The most efficient development of natural resources is an ideal that, from a material point of view, appeals to the engineer. This ideal includes giving of opportunities to everyone to take a share in the development of these resources.. It also contemplates rewarding foresight

Jan 4, 1919

By B. H. Cody

The Morenci concentrator of the Phelps Dodge Corporation is a part of the project that was completed after five years had been spent in development of the open-pit mine, equipment and process testing in the former No. 6 concentrator, and construction of the reduction works. The reduction works, of which the concentrator is a part, is about a mile and a quarter southeast of Morenci, on the highway that leads up Morenci Canyon. The concentrator has a nominal capacity for the treatment of 45,000 tons of ore daily. The original plant, which has a rated capacity of 25,000 tons of ore daily and is now in its fifth year of operation, began production on Jan. 30, 1942. The addition, to increase the capacity 80 pct, began operation on Dec. I, 1943. The equipment of the original plant has been described in Mining and Metallurgy (May 1942). NO changes in equipment were recommended for installation in the concentrator extension and only one major change, forced by a shortage of maintenance labor, has since been made. Metallurgical treatment has been altered in some ways as experiments progressed and as labor and economic conditions dictated. No complete description of the operation of the concentrator has been published, so this paper will record such operating and equipment changes as have been necessary, the operating methods that have been developed and the metallurgical results that have been obtained. Descriptions are given in the order of the processes with a flowsheet and an equipment list of each process for convenient reference. The questions asked by engineer visitors have guided the detail in which operation and maintenance are described. During the period Jan. 30, 1942 to Sept. I, 1946, ore milled has totaled 43,595,253 dry tons, from which 1,643,885 tons of concentrate have been made, containing an indicated production of 783,164,-809 lb of copper. The principal results obtained in operation of the concentrator during the years 1942 to 1945, inclusive, and to Sept. I, 1946 are shown in Table I. A graphic general flowsheet of the plant is given in Fig I. Ore The Morenci ore that is now being treated is a medium-hard monzonite porphyry in which the principal sulphide minerals are chalcocite and pyrite. A minor amount of covellite is present. Chalcopyrite and bornite have been observed under the microscope. The chalcocite occurs mainly as a coating on pyrite. Some of the coatings are so thick that the pyrite presents the appearance of being an inclusion in chalcocite. Some are less than one micron thick and are barely visible at 500 diameters magnification of a polished cross section. Some chalcocite is present as a in in the gangue. Various oxidized copper minerals are present as a result of oxidation in place but they represent a minor proportion of the copper minerals of the ore body. Oxidation

Jan 1, 1949

By B. R. Hollebone

The chemical action of molten anhydrous pyridinium chloride (pyridine hydrochloride) on oxy salts and ores of some Group IV and V metals are discussed-in particular zirconium, hafnium, niobium (columbium) , and tantalum. Laboratory-scale experiments are described whose results suggest that this reaction might provide a practicable means of converting ores of these metals to the anhydrous metal chlorides. Experimental results are given which provide some insight into the nature of the reactions and some of the compounds which could be present at intermediate stages. The treatment of ores of the more refractory metals is difficult and expensive and often demands the use of gaseous chlorine, hydrogen fluoride, or other reagents which are, if nothing else, expensive and dangerous to use. This situation is, of course, due to the strong metal-oxygen affinity resulting from the high charge and the small size of the metal ion which combine to produce such high lattice energy in the metal oxide as to defeat standard reduction methods. Thus, the characteristic of these metals which leads to one of their most important properties—corrosion resistance—is the main hurdle in obtaining the metal. Many common methods&apos; for treating ores of zirconium and niobium (columbium), for example, proceed as directly as possible to the preparation of anhydrous halides. These halides are purified by now standard processes of solvent extraction, fractional distillation, and so on. This paper reports on preliminary stages in the development of a method of treating these ores—particularly of niobium—so as to prepare the anhydrous, volatile halides by the use of chemical reagents which are much more easily handled than those used at present. CHEMICAL PRINCIPLES The solvent action of aminium halides has been referred to periodically in the literature over several decades. The chemistry of pyridinium chloride has been discussed particularly by Audreith2 and Starke.3 However, since this is not familiar chemistry in its nonaqueous setting, it is perhaps well to point out some general metallurgical principles and applications. One can use, as point of departure, the fact that HC1 dissolved in pyridine is an acid very much the same as aqueous HC1. It thus gives essentially all the reactions of the HC1 with which we are familiar. However, when the ratio of HC1:pyridine reaches 1:l (a ratio far higher than is possible with H2O) the solution becomes solid C5F5NHC1, pyridinium chloride.* Inter- estingly, the acidic properties of HC1 persist in this medium, although they are manifest only in the molten state of the compound. Some typical reactions of divalent metal compounds which we have carried out in our laboratories are the following: 2PyHCl + Zn — (ZnCl2) + H2 + 2Py 2PyHCl + MnO — (MnCl2) + H2O + 2Py 2PyHCl + CuS — (CuCl2) + H2S + 2Py 2PyHCl + CaCO3 — (CaCl2) + H2O + CO2 + 2Py In these equations, the parentheses indicate a solvated compound which in water would be predominantly a hydra ted cation but which in molten PyHCl will more likely be a complex chloro-anion of the type MC14-. Some important physical properties of pyridinium chloride (PyHCl) are given in Table I. One sees from the data in Table I that at the temperature of molten pyridinium chloride both water and pyridine will boil away. Thus the system will be kept anhydrous. For this reason the reaction 2NbCl5 + 5H2O— Nb2O5 + 10HC1 has no counterpart in molten PyHCl. Instead, the chloride is made even more stable by the formation of a hexachloro complex: Nb2O5 + 12PyHC1 — 2PyHNbC16 + 5H2O + 10Py One interesting property of these complexes is their thermal instability which for the case of niobium can be illustrated as PyHNbCl6 — PyHCl + NbCl5 With a view to possible use of this chemistry in ore treatment, we have attempted to dissolve Pyrochlore (essentially FeO - Nb2O5) and recover the NbC15 from it.

Jan 1, 1968

By Donald L. Katz

THE Oklahoma City Wilcox sand, discovered on March 26, 1930, has produced 394 million barrels of crude oil and 819 billion cubic feet of natural gas as of July 1, 1941. The 100,000-bbl. wells, pressures of 2600 lb. per sq. in., and flows of "Wilcox" sand caused exciting moments in the early life of the field. Today the reservoir is substantially at atmospheric pressure and produces 75,000 bbl. of crude oil daily through 466 pumping wells. Early estimates of the initial crude-oil content of the "Wilcox" sand&apos; indicated that about 600 million barrels of crude oil would remain after the pumping wells ceased to produce economically. The Oklahoma City Wilcox Secondary Recovery Association was organized in March 1939, to study the possibilities of recovering a portion of this oil. Only a very brief summary of the information available can be presented in a paper of this nature. Some simplification and generalizations are necessary to give the over-all picture in so short a space and statements made may not apply to a specific well or small area. Since the area under consideration by the Association is that north of the south line of section 22-11-3, some information will be presented for areas A, B, C, r, 2, 3 and part of 4 of Fig. 2, and some will be for the entire Wilcox zone west of the fault. This paper is essentially an abstract of an engineering report made by A. D. Small, B. T. Murphree, M. C. Sons and the author for the Oklahoma City. Wilcox Secondary Recovery Association on Sept. 5;.1940. Some information is taken from a report to the Association by C. V. Sidwell on March 1, 1940, and some data are from a recent report by A. D. Small. It gives a brief history of the Wilcox zone, estimates of the initial oil contents of the reservoir, present conditions in the reservoir, and probable results from several programs of "secondary recovery." HISTORY OF WILCOX ZONE The Wilcox sand lies on the flank of the general structure, as shown by cross section of Fig. 12.1 .4 and areal map of Fig. 2. The sand is of Ordivician age and is composed of well assorted, rounded&apos; sand grains with no apparent cementing material. The loose texture of the sand is shown by the enormous quantities of sand production from the wells and from the soft cores. The productive sand varies from zero thickness on the east to 220 ft. maximum and to zero thickness on the west because of water. The development of the pool4 was dependent upon drilling restrictions within the city limits, which accounts for the spacing of drilling operations listed in Table I by years. In 1931, areas I through 7 of Fig. 2 were open for drilling with the exception of some west-edge properties, and all wells drilled before Feb. I, 1935, were in this portion of the field. Nearly all wells drilled from 1933 to 1937 were in areas A, B and C. Since 1939, the newly drilled wells have gradually enlarged the producing area toward the west in the northern portion.

Jan 1, 1941

By L. G. Jones

An approximate method of calculation is developed in this paper which allows duplication of radial unsteady-state gas flow computer results where Darcy&apos;s law applies, such as those reported by Aronofsky and Jenkins and Bruce, Peaceman, Rachford, and Rice. Moreover, the new calculation method can be used to obtain results for radial unsteady-state gas flow obeying the quadratic flow law proposed by Duwez and Green. Means are discussed for predicting well behavior at single or superimposed flow rates in finite or infinite reservoirs, determining reservoir rock properties from well-test data, reproducing and interpreting back-pressure test data, and determining the radial extent and reserves of gas reservoirs from well-test data. Example calculations are presented for gas flow following both Darcy&apos;s law and the quadratic flow law. INTRODUCTION Since the publishing of U. S. Bureau of Mines Monograph 7,1 most gas-well testing methods have been based on the equation q = y (pl2 - pw2)a, where q = production rate, pl and pw, are formation pressure and sandface pressure, respectively, and y and a are constants to be obtained from test data. These methods, used for predicting both deliverability and "open-flow" capacity of gas wells, have been useful and accurate in many cases but unsatisfactory in others. Even at best, however, they do not supply information about the formation or lead to an understanding of nonsteady-state gas flow in porous media. Many theoretically based studies2-4 of gas flow obeying Darcy&apos;s law have been made.&apos; Since the partial differential equations which result from combining Darcy&apos;s flow law with the continuity equation are nonlinear, most of the published research consists of either numerical solutions or analytical solutions for linear approximating equations. Such solutions have been of limited value in field work due to their unhandy form and their failure to correlate most field data. There is evidence5,6 which indicates that Darcy&apos;s law is inadequate to describe gas flow at some flow rates of practical interest. A quadratic flow law: which reduces to Darcy&apos;s law at low rates, is more successful in accounting for experimentally observed behavior. This flow law has been applied successfully to a few hypothetical reservoir cases in work which has recently been published.10 However, these numerical solutions of the equations involved have been successful only on a special analog computer. Routine applications to field cases would be awkward and have not been attempted. The present paper describes an approximate method for computing nonsteady-state gas flow solutions which has been completely successful in predicting the results for both Darcy flow and quadratic flow obtained by elaborate numerical methods. The new calculation method allows determination of the observable variables in gas-well testing at constant rates. It is similar to the scheme of using a succession of steady states suggested by Muskat7 in that it makes use of steady-state and material-balance equations. It also is similar to the work of Aronofsky and Jenkins2 in that the new method includes Aronofsky and Jenkins&apos; stabilized flow equation as a special case. It improves upon both of these calculation schemes in that it accurately describes all portions of reservoir history and suggests means of determining reservoir rock properties from well-test data. This paper deals only with production from a reservoir, in which case the rate is defined as being negative. The reservoir studied here is a homogeneous, disk-shaped porous body of uniform thickness, with all boundaries sealed except the inner radial boundary of the well.

By J. Marshall Rounsevell

It is probably not too far from the truth to say that the sulfur content of the steel bath at the first turndown of the basic oxygen furnace is influenced by every factor which varies in the operation of a BOF shop. However, the determination from normal shop operating data of the effect of a given factor on turndown sulfur content requires a means for collecting a large quantity of such data and a significant variation of the factor in question in that data. In this paper, operating data from 4000 heats collected on the computer at Inland&apos;s No. 4 BOF Shop is utilized to analyze the effect of four operating parameters -- hot metal sulfur content, hot metal manganese content, percent burnt dolomitic lime (dolomite) in the flux charge, and the presence or absence of transfer ladle slag skimming -- on first turndown sulfur content.

Jan 1, 1972

By T. A. Wright

THE-Institute of Metals Division opened on Tuesday afternoon with Wheeler P. Davey as chairman and G. E. Edmunds as vice-chairman. Four papers were on the program, two being of a fundamental character. A paper on "Internal Surface in Minerals and Metals," by R. S. Dean and J. Roster, was presented by the latter; C. H. Gottschalk discussed coercive forces in powders. In answer to a question by the chairman. The author stated that he had not investigated [he temperature coefficient of resistance. A paper on "Recrystallization and Grain Growth in Cold Worked Polycrystalline Metals," by L. W. Eastwood, Arthur E. Bousu, &apos;and C. T. Eddy, was presented by Mr. Eastwood. A. great many quantitative data were given, with little reference to the theory. Theoretical considerations were discussed by Dr. Gottschalk, and C. A. Edwards of the University College of Wales, contributed very interesting comment on the relationship of size and critical strain. Dr. Edwards discussed the necessity of considering strain with time and temperature.

Jan 1, 1935

By JAS. F. McCARTHY

THE present Hecla Co. is a Washington corporation; the Hecla Co. of Idaho was the old company. The older corporation owned two claims, the Hecla and the Katie May, and was incorporated for 500,000 shares of one dollar par value. The principal shareholders and officials of the older company were among the early mining men of the camp. Among the active officials were John A. Finch and A. B. Campbell. Among the directors and share- holders were Patrick Clark, J. R. Smith, Frank Upman, F. J, Kipp, Chas. Kipp, B. A. Kipp and Carl Landsee. F. J. Kipp and Carl Landsee are now directors of the Company. All of the others mentioned have died, but the surviving members of their families retain their ownership in the Company&apos;s shareholders. B. A. ,Kipp, who recently died, was the largest shareholder at the time of incorporation and Patrick Clark was the second largest shareholder. B. A. Kipp is a brother &apos;of F. J. Kipp, director of the Company.

Jan 1, 1924