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URANIUM is commonly recovered by either column ion exchange (IX) or basket ion exchange (RIP) from solutions resulting from sulfuric acid leaching of uranium-bearing ores. In both operations a solid state ion exchanging resin is used, the major difference being that practically clear uranium pregnant solutions are required for passage through resin columns whereas in RIP, leach slurries from which only the sands have been removed are caused to flow through ion exchanging resins contained in baskets. The solvent extraction process as used for recovering uranium from acid leach solutions is also an ion exchanging process, but one in which the ion exchanging medium is a liquid rather than a solid state resin. For this reason, SX is often referred to as liquid ion exchange, although liquid- liquid extraction is probably more accurate. Uranium in its sulfuric acid leach solutions exists in an equilibrium that may be visualized as follows: [ ] Because of an equilibrium of this nature, uranium may be recovered on either cation exchanging or anion exchanging resins and then concentrated during the resin eluting operation. Similarly, solvent extraction processes may utilize either anion ex- changing or cation exchanging liquid organic phases, which capture the uranium and permit its subsequent concentration when the organic phase is stripped.

Jan 9, 1957

PITTSBURG MEETING The One Hundred and Ninth Meeting of the Institute, for the presentation and discussion of technical papers, will be held at Pittsburg, Pa., Oct. 8, 9 and 10, 1914. This meeting is to be under the auspices of the Iron and Steel Committee, the Committee on Petroleum and Gas, the Committee on Coal and Coke, and the Committee on Non-metallic Minerals. Thirty papers have been secured by these Committees and will be presented at the meeting. These papers will be published in the September and October Bulletins. The Local Committee of Arrangements for this meeting is as follows: SAMUEL A. TAYLOR, Chairman. FRANCIS C. PHILLIPS. GEORGE S. RICE. C. F. V. Rys. KENNETH SEAVER. JOHN S. UNGER.

Jan 9, 1914

By A. W. Ashbrook

There are many methods of analysis available for compounds similar to those used in solvent extraction processes. However, the majority of these methods are not directly applicable to the determination of solvent extraction reagents, especially in raffinates. The number which are applicable is further reduced if limited to the more simple methods suitable for process control purposes. Commercial extractants are complex mixtures. The complexity is increased by the addition of diluents and modifiers in two-phase systems containing metals. Raffinates from solvent extraction processes contain the more polar components of the extractants and the products of decomposition. Only a limited amount of information is provided by total organic carbon or spectrophotometric analysis. The complexities of the systems require a combination of methods.

Jan 1, 1978

By John L. Walte

Consolidation Coal Co.'s Renton mine, a 680 000-t/y (750,000-stpy) underground operation located in western Pennsylvania, has reduced the time required for overcast construction in its advancing operations by adopting a prebolting technique followed by multiple blasting. In the past, the mine's overcasts had been excavated by the continuous mining machines used to advance the section. More recently, the overcasts were blasted down and then rebolted with a stoper drill. The new system, using a two-part combination bolt, has proven very successful in speeding up overall construction time and providing more positive horizontal control in blasting. The prebolting approach allows the roof to be blasted down and loaded out without the need for rebolting the shot-out area.

Jan 6, 1978

By Charles W. Merrill

WHETHER the valuable components in a mineral deposit can be mined and separated from the worthless matrix, processed, and marketed depends not only upon the natural factors and the physical and chemical techniques, but also upon many extrinsic factors relevant to the economics of the business of exploring, developing, and producing minerals. To meet a need for proper coverage of this specialized field of economics, the Mineral Economics Div. of the AIME has developed a plan for assembling a volume setting forth important factors affecting mineral enterprises other than those that lend themselves to solution through science or technology. The program has been considered by the Institute's Directors and they have approved it, subject to a decision of the Mineral Economics Div. to carry it out.*

Jan 8, 1954

By W. R. Phibbs

THE blast furnace of the Columbia Steel Corpn., at Ironton; Utah, was put in blast April 30, 1924, and its operation has presented some interesting problems. The coke for the furnace is furnished by 33 Koppers Becker type ovens of 15 tons capacity each. The coal is shipped from the company's mine at Columbia, Utah, which is approximately 123 miles from Ironton, and is probably the highest volatile coal that is being coked for blast furnace use in this country. The analysis of the coal is: PER CENT. Moisture 3.90 Volatile 39.00 Fixed carbon 51.10 Ash.... 6.00 Sulfur : 1.07 The analysis of the coke is: PER CENT. Volatile 0.55 Fixed carbon :...:.::: :..:.:: 89.70 Ash 9.75 Sulfur 1.05

Jan 1, 1928

By Edward Sampson

Despite the many industrial uses, the world market for silver as a commodity is far from free, being dominated by the U.S. Government both through acts of Congress and by policy of the Treasury Department. This discussion will consider aspects of supply, demand, and price with a view to the future. Changes in Sources of Supply: The world's peak production of silver, 278 million oz, was in 1937. In the 1850's world production was about 30 million oz, having risen from a yearly average of 11 million oz for the first half of the century. From 1860 to 1940 there was a steady rise, broken only by World War I and the depression of the early 1930's.

Jan 7, 1960

By John Birkinbine

IN all metallurgical processes and mining operations, water is an element which receives attention from the management ; and provision is required either for a means of supply, or for the disposal of accumulation. In many works the quantity of water to be furnished is sufficiently large to place the item of water supply of equal importance to the reception of material or disposition of product ; and the means to be employed receive, or should receive, the most careful investigation. There are exceptional cases where mines or quarries possess a natural drainage, but a large majority of the useful ores and the fuels delved from the earth are obtained from workings in which water accumulates and must be removed. Often the quantity to be

Jan 1, 1877

By John Birkinbine

In all metallurgical processes and mining operations, water is an element which receives attention from the management; and provision is required either for a means of supply, or for the disposal of accumulation. In many works the quantity of water to be furnished is sufficiently large to place the item of water supply of equal importance to the reception of material or disposition of product; and the means to be employed receive, or should receive, the most careful investigation. There are exceptional cases where mines or quarries possess a natural drainage, but a large majority of the useful ores and the fuels delved from the earth are obtained from workings in which water accumulates and .must be removed. Often the quantity to be

By AIME

HAPPILY, a large group of the non-ferrous fraternity have long valued a personal association with the new Chairman of the Institute of Metals Division. Many others who will meet him, either officially or unofficially this year, will find themselves sharing the enthusiasm with which he has been welcomed to his new office. Albert A. Smith, Jr., was born at Butler, N. J., on Dec. 28, 1904, and moved to New Haven in time to initiate his preparation for Yale University on the home grounds. After receiving a B.S. degree cum laude in 1926, he stayed on for graduate work at the Hammond Laboratory under C. H. Mathewson, and was awarded an M.S. degree in 1928.

Jan 1, 1948

By C. N. Garman

Homestake-New Mexico Partners operate a 750-tpd carbonate leach uranium concentrate mill near Grants, N.M. The highly mineralized water available as process water leaves much to be desired. The 628 ppm as CaCO 3 makes the use of raw water very troublesome in pipes and on filter cloths. However, the residual sodium carbonate in the final filter cake going to tails makes an ideal softening agent. To take advantage of this fact, all makeup water used in the mill is first used as tailing slurry dilution water and comes to the mill from the tailings pond. The 5-acre tailings pond serves as a thickener and 100 to 150 gpm of nearly clear solution is decanted to a pump to be returned to the mill. Since this tailings water has small quantities of uranium in the solution an ion exchange scavenger unit was installed to remove as much uranium as possible. The ion exchange raffinate is then used as final filter wash ahead of the tailings slurrying step. In spite of the large settling area this return water is not clean enough for ion exchange feed. The solids present are very fine and composed of approximately 15 pct (by weight) burnable carbonaceous material common to the sandstone uranium ores in the area, 40 pct SiOz plus 45 pct CaC03. Laboratory work showed that this material responds very well to flotation. Before deciding to use flotation, various clarifying systems such as pressure leaf filters, sand filters, and continuous vacuum pre-coat filters, were considered. Each of these could have solved the problem but with much more operating labor, more reagents and greater installation costs than the flotation step. About 100 to 150 gpm of fouled water is fed to two 66-in. Fagergren cells, in series. Reagents used at the beginning were Arquad 2HT75 and Arquad C50, at the rate of about 1% lb per 8-hr shift, or about 0.0053 lb each per ton of ore. This did not completely remove the solids but does an acceptable job. Approximately 75 pct of the slimes are a size that can be caught on a 41-Whatman Paper are removed. Removal of these slimes also allows much better settling of the coarse nonfloatable material. Advantage is also taken of this fact in a small settling tank ahead of precipitation. Removal of this amount of the slimes makes the ion t:xchange feasible. PREGNANT SOLUTION CIRCUIT The carbonate? leach-caustic precipitation method of uranium concertration does not provide for any process purification step ahead of precipitation. Therefore, any fine solids getting into the pregnant solution through the filter cloth show up in the final concentrate. This, of course, lowers the grade, and, at times, the slimy nature of these very fine solids rendered final filtration of the concentrate difficult if not impossible At Homestake-New Mexico Partners a 75-ft thickener was available for gravity clarification of 100 to 120 gpm of this pregnant solution. However this did not sufficiently remove the slimes. Laboratory investigation of the whole range of flocculants that were suggested by literature, salesmen, and friends failed to turn up anything of consequence. A continuous vacuum pre-coat filter would do the job and was investigated. The capital cost and the operating labor and materials made this a last chance choice. Following work done in the metallurgical laboratory on the tailings return water, it was found that some changes in the reagent strengths and combinations made a very definite decrease in the solids in the pregnant solution. Concentrate grade improved about 5 pct anti the final product after drying had an appreciably greater bulk density. Compared to a cost of about 2.2e per ton for pre-coat filter opelation for cleaning just one circuit, flotation costs less than 1.0 per ton of ore for cleaning two circuits. While a pre-coat filter would do a more thorough job, the flotation does all that is required for either circuit. Gravity causes the froth produced to run back into the leach circuit. This does not appear to result in a build-up of objectionable slime. No extra manpower is required; the operators in the separate areas can observe the operation of the cells and mix the small quantities of reagents as needed. Normally the 66-in. Fagergren cell requires 15 hp per cell, but this very dilute slurry needs only 10 hp for both cells. Originally, a combination of the two Arquads mentioned previously served as frothers and promoters. As further testing

Jan 1, 1962

Coal was produced in this state, by white men, at an earlier date than in any state west of the Mississippi River, and for many years its production was larger than that of any state in that area. The coal immediately adjacent to St. Louis was mined commercially earlier than elsewhere because of a ready market which could be reached by teams. Generally the coal seams are more or less "spotty" in character, and in many places openings made in thick coal could only be mined for a few years. All of the data available from state survey reports, county histories and a few other sources are shown in Table 66.

Jan 1, 1942

By H. L. Washburn, G. L. Judy

DURING recent years thermal drying of fine coal has increased at a tremendous rate, but very little discussion of the several excellent units has found its way into print. This is particularly true for operating and maintenance costs, and the operator who is faced with his first fine coal drying installation must depend chiefly on hearsay when trying to determine what his drying costs will be. This article presents the maintenance and operating costs for the seven drying units now installed in preparation plants of Pittsburgh Consolidation Coal Co. and lists other cost information that should be obtained before any particular drying unit is selected.

Jan 10, 1957

By O. N. Carlson, E. D. Gibson, D. W. Bare

SEVERAL investigators have recently contributed to a clarification of the controversy concerning the allotropy of chromium. Ross and Hume-Rothery1 and Vasyutinskii et a1.2 have reported high-temperature X-ray data on unalloyed chromium from which they have concluded that no allotropic transformation occurs in this metal. Bechtoldt and vacher3 in their investigation of the Cr-Ni alloy system found no evidence for a transformation in chromium and Smart and Haynes4 in critically analyzing the data presented to date concerning this system could find no evidence for a eutectoid reaction in this system. Wyder and Hoch5 in research concurrent with our

Jan 1, 1964

By P. T. Carter, A. B. Murad, H. B. Bell

N. A. Gokcen (Michigan College of Mining and Technology, Houghton, Mich.)—The activities of silica, represented in Fig. 5 for the systems MnO-SiO2 and CaO-SiO2, are in disagreement with the established binary phase diagrams. At Ns102 = 0.50 in MnO-SiO2, and at Ns102, = 0.65 in CaO-SiO2, each binary system is saturated with respect to silica at 1550°C, and therefore as102, is unity in each case. The curves for as102 (FeO-SiO2) and as102, (MnO-SiO,) should nearly co-

Jan 1, 1953

By Robert J. Morris, John N. Butler

A series of organic collectors has been developed which successfully float synthetic secondary uranium minerals, such as autunite, carnotite, and torbernite. Recoveries up to 97 pct have been obtained. With cleaning of rougher concentrates, ratios of concentration as high as 15:l are possible on head assays of 0.10 to 0.50 pct U308. Additions of certain base metal salts aid in recovery and materially in- crease the rate of flotation and selectivity of the collectors for the synthetic minerals. Flotation tests on natural uranium minerals have not yet equaled results obtained on the synthetics, although these collectors do give better results than conventional collectors for nonsulfide minerals.

Oct 1, 1956

By Susan B. Leiter

That oxygen in copper has been a source of trouble is well known and that that trouble has been real in the commercial world has been shown by Fuller.' Moore and Beckinsale's paper2 at the annual meeting of the Institute of Metals in London, 1921, called forth considerable discussion. Prof. T. Turner expressed the opinion that it was not necessary to have cuprous oxide present in sufficiently large quantities to form either globules or seams in order to produce a bad effect if the copper were gassed. This brought up the question of the solubility of oxygen in copper and the authors desired to know whether there were any evidence of such solubility, because their experience was that whenever there was any oxygen in copper it was present in the form of free cuprous oxide, which was practically always in the form of globules. Later Hanson, Marryat, and Ford3 stated that 'for all practical purposes cuprous oxide may be regarded as insoluble in copper. However, they found particles of the eutectic to coalesce to form much larger particles. They suggested that cuprous oxide was actually slightly soluble in copper, for it was difficult otherwise to understand the mechanism by which such coalescence could take place. W. E. Ruder, in discussing that paper, said that his experiments had led him to conclude that a slight solubility must exist to allow for the ready coalescence of oxide particles, but conductivity tests convinced him that that solubility was very small. Nevertheless, there appeared to be a state of admixture of oxide with copper that closely resembled a colloidal mixture which at first was mistaken for a true solution and which usually existed at the grain boundaries. The purpose of this paper is to give the results of some investigations, begun in September, 1921, which would seem to show that although cuprous oxide may be only slightly soluble: (1) this solubility is sufficient

Jan 1, 1926

By A. Long, A. Silverman, J. L. Kulp

Garth Crosby has written an excellent geologic description of the deposits surrounding the Gem stocks in the Coeur d'Alene district. The ore deposits in the area of the Gem stocks may hold the key to the age and mineralization history of the entire Coeur d'Alene district. A recent isotopic study10 of the Coeur d'Alene district in this laboratory illustrates that a classical geologic interpretation of these deposits, with its implications for the whole district, may lead to erroneous conclusions. For this reason it seems pertinent to submit a summary of these results and an interpretation of the mineralizing history of the Coeur d'Alene districts. Pitchblende from the Sunshine mine has been dated as 1100-1200 million years (m.y.) by Kerr and Kulp,11 and Eckelmann and Kulp.12 This pitchblende is known to predate the major sulphide introduction in the Sunshine mine, but it clearly follows the metamorphism and folding of the Belt Series. Recently, Goldich (personal communication) dated sericite from the Belt rocks as 1200 m.y. by the potassium-argon method. This date establishes a minimum Belt age if the sericite is of metamorphic origin and a maximum age if detrital. The Belt Series, therefore, is not latest Precambrian. Lead isotope ratios of galenas have been measured and model ages calculated by Bate, et all3 for the Sunshine mine, Farquhar and Cummingl4 or the Bunker Hill and Sullivan mine, and Cannonl6,18 for a few other deposits in the district. Galenas from similar deposits in Southern British Columbia have been measured by Bate, et al,23 Farquhar and Gumming,11 and Wanless and Leech." The new work in this laboratory includes leads from ten widely scattered mines north and south of the Osburn fault, and through a vertical distance of over 5000 ft (Star mine). Included in this group are the Hercules, Sunset, and Mountain Goat mines, which are adjacent to the Gem stocks. In addition, galenas from stringers which cut the Gem stocks in the Success and Sunrise mines and the Hercules hanging wall dike in the lower western portion of the Hercules mine, were included in the study. All of the above leads, except one, give model ages of 1300-1400 m.y. for the time of segregation from the parent material. The concordance of the common lead and U-Pb ages, the great horizontal and vertical uniformity of the lead ratios, the sulphur ratios of two Sunshine mine galenas and three galenas from the Edith, Page, and Hercules mines indicating average crustal sulphur, and the U23/Pb204 ratio inferred for the original lead environment, indicate that the entire mineralization of the Coeur d'Alene-British Columbia base metal belt was derived from a deep source and emplaced in the Precambrian. One sample of galena from sulphide stringers cutting the North Gem stock at the Sunrise Prospect mine gave a modern (i.e., Tertiary) lead ratio. This mine is located at the northern tip of the stock. The presence of modern lead suggests mobilization of some rock lead during the intrusion of the Gem stocks and their outliers. Larsen et al.l8 have dated the Gem stocks as Tertiary by the lead alpha method. If Coeur d'Alene mineralization was genetically related to Tertiary magma formation and intrusion

Jan 1, 1961

By W. A. Backofen, B. B. Hundy

THE pole figure interpretation in a recent paper' on the torsion texture of copper was questioned in discussion,2 nd a simpler alternative interpretation was proposed. In the hope of reaching a positive decision in favor of one or the other, further studies were undertaken with 70-30 brass and Armco iron. This additional work has not answered all the questions about torsion textures, but the new pole figures do offer support for the original interpretation and show that the texture is more complicated than the alternative suggests. From the previous paper,' the appropriate method of describing the texture in a twisted bar is known to be a pole figure plotted on a plane tangent to the surface of the bar. The axes of the pole figure are chosen to coincide with directions in the tangent plane which are parallel and at right angles to the bar axis (the longitudinal direction, L.D., and the transverse direction, T.D.), for these directions define symmetry axes of the texture. Therefore any ideal orientation that might be selected to represent the texture gives the crystallographic plane parallel to the tangent plane and the crystallographic direction parallel to the axis of the torsion specimen. A unique texture was assumed in the original interpretation, and the four ideal orientations, (112) [111], (111) [112], (110) [001], and (112) [131], were used in its description. Of the four orientations, the first three provide possible slip directions along the direction labeled T.D. in the pole figure, which is one of maximum shear stress in a specimen being twisted. The alternative, however, simply considered the texture to be made up of two components, one a [Ill] alignment along the specimen axis with a random orientation about the axis as in the wire texture, and the other a superimposed orientation (110) [0011. Experimental evidence for this simpler interpretation was derived from two observations: 1—twisting did not alter the orientation of a single-crystal torsion specimen of a brass in which an octahedral plane was perpendicular (and a [Ill] direction parallel) to the axis, and 2—deformation bands with approximately the (110) [001] orientation were seen to develop in the crystal during the test. The new pole figures were obtained with a brass and an iron torsion specimen of 3/4 and 1 in. gage length diameter, respectively. After annealing, polishing, and twisting, seven rods, about 0.030 in. in diameter and with different orientations, were prepared from material near the surface of each specimen; these were required for the method of constructing pole figures by using a Geiger counter as developed by Norton.5 Since the shear strain gradient in plastic torsion is linear, it was readily computed that the material supplying the brass rods had been subjected to a shear strain of about 3.2, and that supplying the iron rods had received a shear strain of about 2. All details concerning specimen design, testing procedure, rod preparation, and use of the Norton technique can be found in ref. 1. Only this procedure was followed in working out the (111) and (100) pole figures for brass, Figs. 1 and 2. However, X-ray photograms were also involved in the construction of the (110) pole figure for Armco iron, Fig. 3. The photograms were made according to the conventional transmission diffraction technique using a small sheet taken parallel to the specimen surface and etched to a thickness of about 0.0025 in. They were especially important in locating the boundaries

Jan 1, 1954

Increased world consumption of crude and products coupled with the trend toward supplying this demand from the nearest and most economical source of supply had the economic effect of broadening the demand for Venezuelan crude. As a result of this, Venezucla produced more in 1934 than in 1929, the previous peak year. During 1934 Venezuelan output is estimated at a total of 139,382,000 bbl., a daily average of 381,868 bbl., against 120,442,000 bbl. in 1933, a daily average of 329,978 bbl. This is an increase of 51,890 bbl. per day. It is interesting to note from the comparison of production for the past 10 years (Table 1) that in spite of the fact that Venezuela produced more in 1934 than in 1929 its share of world production is slightly less than in 1929 and 1930. During the latter part of 1934 Vcnezuela produced its first billionth barrel of crude. Only three other crude-producing countries of the world have attained this distinction; namely, United States, Russia and Mexico. Venezuela still ranks third in the producing countries of the world, being surpassed by the United States and Russia. Exports of crude and products from Venezuela for 1934 are estimated at 133,400,000 bbl. This is an increase of 16,107,000 bbl., or 13.73 per cent as compared with 1933.

Jan 1, 1935