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By L. H. de Wald, J. Walter Scott

It is usual practice in the copper industry to use open horizontal molds for casting tough-pitch copper wire bars.' A wire bar cast in this manner is partly characterized by heavy wrinkles and a comparatively deep skin of oxide on the top of the bar, corresponding to the open side of the mold. On the theory that the rough, high-oxide surface might have an adverse effect on the rolling and drawing properties of a wire bar and might account for some of the irregularities of mill behavior, several bars which had been planed to remove the wrinkled surface were processed into wire. These bars responded to mill treatment more satisfactorily than did the regular wire bars. Realizing that machining the surface of one face of each bar would not be commercially feasible, it was decided that casting the metal into a vertical mold and cropping off the pouring end would accomplish approximately the same result. Several wire bars of commercial size (250 Ib.) were so cast and processed into wire for comparative test with bars cast in the usual horizontal molds. It is the purpose of this paper to present the results obtained from this investigation, in which commercial bar sizes and processing technique were used throughout. The results show that in general copper wire bars cast vertically are superior to those cast horizontally. Experimental Procedure A horizontally cast bar and a vertically cast bar were obtained from each of several regular reverberatory furnace heats of copper which had been refined and poled to tough-pitch metal in accordance with usual methods.' Both bars were cast from the same part of the melt and within five minutes of each other, in order to produce as nearly as possible, in each case, wire bars of identical composition.

Jan 1, 1930

By G. F. Livingston, F. K. Shelton, J. C. Stahl, R. E. Churchward

"INTRODUCTION An investigation of the metallurgy of cobalt from domestic ores has been in progress since February 1940 and has resulted in the formation of a hydrometallurgleal process for the production of electrolytic cobalt metal. Previous reports of these investigations have been given by F. K. Shelton; 7/ and Ruth E. Churchwrd, F. K. Shelton, and G. Knickerbocker. 8/ Briefly, the process, as applied to ores containing cobalt oxide, consists of leaching with H2SO3 or, preferably, with H2SO3 and H2SO4, to dissolve the cobalt. The cobalt solution passes through one or more purification stages to remove iron and elements of the copper group, and cobalt carbonate is precipitated under carefully controlled pH conditions. The cobalt carbonate is dissolved in on acid electrolyte containing sulfuric acid, boric acid, and sodium fluoride. The electrolyte then proceeds to electrolytic cells where cobalt is plated as a metal and sulfuric acid is regenerated.The present paper contains the results of several investigations signed to give a more complete chemical and engineering understanding of different unit processes involved in the electrowinning of colbat. Some work has been done to broaden the process to include arseniferrous cobalt ores as well as the oxide ores upon which the investigation was initiated. Most of the data presented herein have been obtained since the release of the previous reports; any changes suggested heroin that conflict with recommendations in earlier reports are based on more complete data and usually are preferable."

Nov 1, 1945

By H. A. Gardner

THE principal use of barium sulphate is as an inert paint pigment.. For this purpose, the ground material is used both in its natural and in its artificial forms. Probably the largest amount is used in the production of a chemically precipitated pigment called lithopone which consists of 70 parts of barium sulphate and 30 parts of zinc sulphide. An enormous tonnage-of this pigment is at the present time being used in the manufacture of interior flat wall paints of the oil type, such paints having almost entirely supplanted the use of corroded white lead which was at one time used for interior painting. The more dense nature, lower price and sanitary value of lithopone was responsible for this change. Lithopone is, moreover, used to a large extent in the manufacture of oil cloth, shade cloth and linoleum. Its whiteness makes it of particular value for this purpose. Barium sulphate is also used of itself in admixture with other pigments in the manufacture of prepared paints. The chemically precipitated form of barium sulphate, which is generally called blanc fixe, is also used for this purpose. Much controversy has raged in the paint world over the question of inert pigments such as barytes, silica, asbestine and china clay. These pigments are probably called inert because they have no chemical action upon the linseed oil in which they are ground to produce paints, and on account of the fact that they become transparent in oil. It is well known that in the manufacture of paints, opaque white pigments, such as basic carbonate white lead, basic sulphate white lead, zinc oxide etc., are generally used as the grinding base. These base pigments, when ground in oil, react therewith to some slight extent, and they produce white paints which have excellent biding or obscuring value. The inert pigments so-called, when ground in oil and spread out into a thin film, form transparent coatings which have no hiding power. It has been contended, therefore, that the use of barytes or similar inert pigments in paints is resorted to simply for the purpose of cheapening the cost of the product.

Jan 9, 1914

AT THE beginning of October, the outstanding feature in the world's affairs was the Turkish question. The Turks, victorious over the Greeks, repudiated the treaty of Sévres with the Allies and demanded their reestablishment at Con-stantinople and in Thrace. The British resisted, but deserted by the French and Italians, at a military conference at Mudania the Turks obtained about everything that they wanted. Great Britain suffered a loss of prestige that may bear evil fruit in the future. The possession of the Dardanelles by the Turks pro-duced the ruin of Russia and Rumania in the great war, prolonged it two years and made it necessary for America to go in. Disruption of the entente puts the Turks back where they were. In America a strong and spontaneous reaction developed against this, not for any diplomatic reasons, but purely out of the sentiment that the atrocious Turks should be confined to Anatolia. Some strong leadership would have aligned the United States with Great Britain in this matter. As it is, the French have had their way but have alienated much of their American friendship. The temporary composition of Turkish affairs at the Mudania conference had momentous consequences. The Greeks, having expelled King Constantine, in their distress and despair reverted to the guidance of Venizelos. Evacuation of the Grecian military forces and the entire Grecian population from Eastern Thrace began, the people not venturing to remain there. From all accounts their withdrawal, attended by great hardships, was reminiscent of folk movements in the Middle Ages. The vanguard of the Angora Govern-ment set foot in Constantinople, marking the return of the Turks to Europe, while the Allied forces remain-ing there temporarily stood in chagrin. In Great Britain an important element of the Con-servatives withdrew their support from the Coalition Government, thus leading to the resignation of Lloyd George, the installation of Andrew Bonar Law as premier and a general election with a tri-party contest among the Conservatives, Liberals and Labor, called for Nov. 15. Civil war continued in Ireland, but attention was diverted from it by the more important events in the Near East.

Jan 11, 1922

By C. H. North, L. E. Lynd, W. W. Anderson, H. Sicurdson

Since the composition and structure of the beach sand concentrates correspond so closely to what would be expected of ilmenites that have been altered by oxidation and leaching, there is no reason to postulate the existence of the hypothetical compound, arizonite, to account for the composition of titaniferous beach sand concentrates. The four concentrates studied are examples of the different products that can result from various degrees of alteration of primary ilmenite. CONSIDERABLE uncertainty is revealed in the literature regarding the nature of the titanium minerals which make up the bulk of the heavy, opaque fractions of numerous beach sand deposits of the world. An investigation was made, therefore, of beach sand concentrates of North Carolina, Florida, Brazil, and India. Magnetic concentration, X-ray, and microscope data were obtained which show that these concentrates consist essentially of ilmenite and its alteration products. The alteration, brought about by oxidation and leaching of iron values, has resulted in upgrading the ores to a range of 56 to 64 pct TiO², as compared with 52.7 pct in ilmenite of theoretical composition. Conclusions drawn regarding the nature of the dominant titanium-bearing mineral in beach sand deposits have been based mainly on chemical composition, specific gravity, and petrography. This material has usually been referred to as ilmenite or weathered ilrnenite.: It has also been referred to as arizonite because in chemical composition it resembles an Occurrence in in which was described by Palmer' in 1909. The chemical composition of Palmer's arizonite corresponded closely to the formula Fe²O³ . 3TiOs. From approximate measurements of crystal angles on a large imperfect crystal with rounded faces, the

Jan 1, 1955

By T. Egleston

THE materials containing copper which are refined in the United States, are, for the most part, the native, coppers of Lake Superior. Until quite recently but little pig copper was made for sale, and that came principally from the pure sulphurous ores of New England and the South, and was generally sold to refineries not far from the ore furnaces. A small amount found its way into the market which was produced either as the by-product of the treatment of gold and silver ores, or as the result of the treatment of impure copper ores; but both these grades, on account of the impurities they contained, were looked on with suspicion, and were not sought for. All the grapes of pig copper are sold by the unit of copper contents, a great reduction being made in the price when impurities are present. There are at the present time only three works which treat native copper, the two of the Detroit and Lake Superior Copper Company, and the works of C. G. Hussey & Co., in Pittsburgh. There are a few works which smelt sulphurous ores and refine their pig; besides these there are a few small works where pig copper is refined only. Some of these purchase black copper, refine scrap, or simply refine such grades of ingot copper as are found in the market, but mostly that from Lake; Superior, for the purpose of getting it into such shapes that can be handled commercially to advantage, such as in making large plates or high grades of wire for electrical purposes. A number of such works are situated in the Naugatuek Valley and elsewhere in New England. The recent discovery, of valuable ores in Arizona makes it probable that within a few years the refining of copper in the United States will make great developments. Up to the time of the discovery of the mines on Lake Superior, only a very small quantity of native copper had ever been found, not sufficient to justify the erection of works for its special treatment. It had, besides, never been found in very Large masses, so that the discovery of great-blocks of it presented serious difficulties, not only in mining it,† but in bringing it into a merchantable condition. It seemed a very simple process to melt these large masses, * Road at the Lake Superior Meeting, August, 1880. †Transactions American Institute Mining Engineers, vol. vi, page 2S2.

Jan 1, 1881

By Katarina Theander, Robert J. Pugh

The generation of froth with a critical degree of stability and height is an important aspect of the froth flotation. In this paper we have studied the synergism and anti-synergism in frothing behaviour in a mixed flotation collector/frother mixture (a model fatty acid; sodium oleate and a model frother; nonionic (polyethyleneoxide alkyl C14E6). Values of the collector / frother molecular interaction parameters (the ß-parameters) were determined from the surface tension data using regular solution theory. The frothing characteristics of the system were evaluated using a glass column equipped with a series of conductivity electrodes, which enabled the water content of the froth to be determined. From these measurements, the dynamic frothability and static froth stability were determined. It was concluded that the synergism/anti-synergism in frothability was depended on the molecular composition of the surfactant system, the diffusion of monomer to the thin film interface and on the breakdown of the mixed nonionic/anionic micelles.

Jan 1, 2003

The following is a report of the papers submitted to the Papers 'and Publications Committee during 1928: The Committee held nine regular meetings during the year 1928. During that period there were presented to the Institute 214 papers which were acted upon as follows: Accepted as Technical Pub1ications............................ 85 Declined for publication...................................... 16 Action pending, Dec. 31...................................... 25 Manuscripts held for annual volumes, Dec. 31................... 7 Withdrawn temporarily...................................... 1 Accepted as Preprints........................................ 20 Printed for first time in volumes.............................. 35 Published in Mining and Metallurgy........................ 12 Papers in Technical Publication No. 156 (Coal Classification) and not accounted for elsewhere in this table..................... 10 Mimeographed only*................................... 3 Total.................................................. 214 * A considerable number of papers were mimeographed for the annual meeting. Of the 85 papers accepted as Technical Publications 8 were reprinted in the Transactions, 7 in Proceedings of the Institute of Metals Division (1928), 7 in Iron and Steel Technology in 1928, 13 in Geophysical Prospecting, and 50 were in Technical Publication form on Dec. 31. Of the 20 papers accepted as Preprints 1 was reprinted in the Transactions, 13 in Petroleum Development and Technology in 1927, 2 in Geophysical Prospecting, and 4 were in Preprint form on Dec. 31. Of the 35 papers printed for the first time in the various volumes 8 were included in the Transactions, 2 in Proceedings of the Institute of Metals Division (1928), 1 in Iron and Steel Technology in 1928, and 24 in Petroleum Development and Technology in 1927. Of the 12 papers accepted for Mining and Metallurgy 1 was, accepted for Geophysical Prospecting and 1 for the Transactions. There were published in 1928 113 Technical Publications containing a total of 1928 pages, as against 88 in 1927, totaling 1528 pages. The Technical Publications published in 1928 were classified as follows: Group A, Metal Mining, 17 papers (361 pages); B, Milling and Concentration, 4 papers (39 pages); C, Iron and Steel, 15 papers (256 pages); D, Non-ferrous Metallurgy, 13 papers (191 pages); E, Institute of Metals, 36 papers (588 pages); F, Coal and Coke, 15 papers (392 pages); G, Petroleum and Gas, 10 papers (246 pages); H, Non-metallic Minerals, 3 papers (33 pages); I, Mining Geology, 18 papers (356 pages); K, Mining Administration, etc., 3 papers (47 pages); L, Geophysical Prospecting, 21 papers (430 pages).

Jan 1, 1929

By Valentin Garfias

ALTHOUGH Mexico still ranks second in importance as produce for petroleum, the output in 1924 was 7 ½ per cent. less than in 1923 and 30 per cent. less than the peak production of 1921. The decrease may be partly accounted for by labor troubles and revolutionary activities early in the year, although undoubtedly the main factor was the continuous rise of the salt-water level in the South Fields, causing a decline of 24,000,000 bbl. in the production of light oil. Since the middle of 1923, the production of heavy crude has been greater than that of the lighter grade and, in 1924, the output of heavy crude was 2 ½ times that-of the light oil. DEVELOPMENT Drilling operations in the Mexican fields were probably more active in 1924 than in any other year, the greatest activity taking place in the Cacalilao and neighboring fields; toward the end of the year there was an added number of wells drilling in wildcat areas. The number of wells drilled in proved territory was almost twice that of the previous year, the increase taking place in the heavy-oil fields north of Panuco, as only 78 of the 710 wells completed were drilled in the Southern Fields. The percentage of successful completions decreased from 45 per cent., during 1923, to about 38 per cent., during 1924; there was also a noticeable decrease in the average flush production of the new wells. It is interesting to note that notwithstanding the increased drilling activity, the total production declined over 10,000,000 barrels. In the heavy-oil district, 632 wells were completed but only 231, or 36 ½ per cent., were commercially productive. The develop-ment in the Cacalilao area reached its peak in April and May, or about the time the first serious salt-water encroachments took place. Development in the old Panuco and Topila fields was more active than during the previous year, although the salt-water level continued to rise, the high price of crude making such development advisable especially for companies having to protect large-investments.

Jan 3, 1925

By Newell Alford

THE data in this paper were collected to show both the volume and speed with which bituminous mines have indefinitely suspended operation while economic advantage in the industry has so gravely declined. The study was limited to the bituminous coal-mining states east of the Mississippi River, wherein conditions affecting production and demand are more common respectively to all of the mining districts included and represent about 95 per cent of the nation's coal mining. Data for the compilation of these statistics and for the construction of these graphs have been obtained in all cases from state mine depart-ment reports, except from those of Ohio and Virginia. In Virginia essential individual mine data were secured from an authentic source, but no individual Ohio mine information is obtainable, because all Ohio fact-gathering agencies are prohibited by law from revealing such data. In other states the facts were tabulated and later checked with the cooperation of Chief Mine Inspectors. In all, excluding Ohio, over 17,000 individual annual mine returns were examined. Special infor-mation was secured from each state mine department about suspensions in 1932. Accurate information was not available from all states about mine abandonment due to exhaustion of coal reserves, and while these were completed for several states, it has not been shown because it was not perfected for all states. However, the total observed sample was comprehensive enough to show that exhaustion accounts for a very limited part of the suspended production. Wherever mention is made of "suspended production" the largest annual output of the mine in the five years prior to suspension has been taken as the measure of its probable production had it continued to operate. A mine is not regarded in this category, as having suspended, when it merely ceases to produce. The word "suspension" is used only where there is a complete abandonment of activity for an indefinite period, as evidenced by the fact that both ventilation and pumping are discontinued.

Jan 1, 1933

By Newell G. Alford

The data in this paper were collected to show both the volume and speed with which bituminous mines have indefinitely suspended operation while economic advantage in the industry has so gravely declined. The study was limited to the bituminous coal-mining states east of the Mississippi River, wherein conditions affecting production and demand are more common respectively to all of the mining districts included and represent about 95 per cent of the nation's coal mining. Data for the compilation of these statistics and for the construction of these graphs have been obtained in all cases from state mine department reports, except from those of Ohio and Virginia. In Virginia essential individual mine data were secured from an authentic source, but no individual Ohio mine information is obtainable, because all Ohio fact-gathering agencies are prohibited by law from revealing such data. In other states the facts were tabulated and later checked with the cooperation of Chief Mine Inspectors. In all, excluding Ohio, over 17,000 individual annual mine returns were examined. Special information was secured from each state mine department about suspensions in 1932. Accurate information was not available from all states about nine abandonment due to exhaustion of coal reserves, and while these were completed for several states, it has not been shown because it was not perfected for all states. However, the total observed sample mas comprehensive enough to show that exhaustion accounts for a very limited part of the suspended production. Wherever mention is made of '(suspended productionJ' the largest annual output of the mine in the five years prior to suspension has been taken as the measure of its probable production had it continued to operate. A mine is not regarded in this category, as having suspended, when it merely ceases to produce. The word "suspension" is used only where there is a complete abandonment of activity for an indefinite period, as evidenced by the fact that both ventilation and pumping are discontinued.

Jan 1, 1934

By H. C. Kenny

The annealing or softening temperature of cold-worked copper is appreciably increased by almost unbelievably small amounts of silver. As indicated by some data in this paper, the softening temperature of high-conductivity, tough-pitch copper may be increased from 200" to 350" C. by the addition of only 15 oz. per ton (0.052 per cent) of that element. Because it has this higher annealing temperature as compared with the silver-free metal, silver-bearing copper finds considerable use in industry. For example, when hard-rolled copper is used in operations that involve soldering or tinning, silver-bearing copper insures against loss of strength, whereas silver-free copper becomes "dead soft." Yet—though several investigators, beginning with Caesar and Gernerl in 1916, have shown that small amounts of silver do definitely raise the softening temperature of copper—data are lacking on the problem: What is the specific influence of different amounts of silver on this temperature? It was to help in filling this gap in the knowledge of what might be termed "alloy coppers" that the data given herein were obtained. The softening of cold-worked copper depends, of course, on a number of factors, of which the composition of the material is only one. Other highly important factors are the degree to which the material is cold-worked and the time it is held at the annealing temperature. The method of cold working and the grain size of the metal produced are also significant. All these variables were taken into account in the investigation reported here, and the influence of silver on the electrical conductivity and on the working was also considered. The coppers used in the softening tests were Lake coppers melted and cast by the Calumet and Hecla Consolidated Copper Co. The ires were fabricated by the Roebling Wire Co. and the sheets were rolled at the Battelle Memorial Institute. Partial analyses of some of the coppers are listed in Table 1, with their electrical conductivities.

Jan 1, 1934

By A. J. Basu

Air quality in underground mining operations can fluctuate significantly during the working day, but until recently the only way to ensure a mine had sufficient air quality was to over-ventilate and, with significant delay in adjusting the volume or direction of the airflow, working conditions were tolerable but rarely ideal. Underground ventilation management systems have been considered to achieve improved energy efficiency since at least 1995 in Canada. However, Mine Ventilation Optimization, (MVO) and integrating it with Ventilation on Demand (VOD) is only becoming more of a reality in the last seven (7) years. A systems approach to MVO takes into account all the elements from the point the power is distributed into the ventilation fans through to the actual quality and quantity of fresh air to the working face. Opportunities exist throughout the system for energy savings but not all of them are cost-effective. Depending on the application, these opportunities can be easily realized by properly sizing, streamlining, maintaining and operating the ventilation system using premium mine proven energy efficient components throughout. Implementation of VOD is a key step in achieving the MVO objective. However, VOD is a concept, and it requires various tools, procedures, and strategies for cost-effective and operationally viable implementations. This paper provides a historical background in the development of VOD and provides a framework for proper and cost effective implementation. In addition, an optimized ventilation system will also allow increased airflow by reducing resistances and shock losses. This turn in would allow production target improvement, which could be an attractive objective compared to energy savings. Mine ventilation is the life support system of an underground mine, and contributes to sustainable development and corporate social responsibility goals assuring health and safety aspects of strategic planning. The proposed framework addresses implementing mine ventilation optimization integrating ventilation on demand as a vehicle for energy, health and safety improvement and overall productivity gains in the mining cycle efficiency while significantly reducing carbon footprint of a mine.

Aug 1, 2013

IN describing the mining and treatment of ore at the Broken Hill Proprietary mine E. J. Horwood, superintendent of mines, gave the following account of the development of flotation there. It was in 1902 that the recovery of zinc from the ore by flotation was hit upon. The former general man-ager, Mr. Delprat, directed our then research officer, Mr. Carmichael, to try boiling the tailing with salt cake of which there was a considerable tonnage left over from the leaching process. The idea was the possibility of dissolving the zinc. Carmichael made the. Experi-ment, but, rather discouraged, took the glass beaker down to the general manager's office, remarking that he could not get the stuff to settle. On showing the beaker to Mr. Delprat, the latter recognized the marked distinction between the black scum on the surface and the rest of the tailings, and exclaimed: "Why, this is the very thing we are after; the zinc is floating!" Patents were applied for at once, but later on it was found that another investigator, Potter, had already hit upon the idea of flotation. His patents, however, were so involved with other operations that his process was impracticable. Litigation followed, but in the end the B. H. P. paid the Potter Company a substantial sum as settlement. In the case of Carmichael's beaker, the acid in the salt cake acted on the small amount of carbonate present in the ore, producing CO. bubbles. Owing to the aversion of sulfide crystals to being wetted, the gas as generated attached itself to the zinc in in-creasing quantities until there was sufficient to buoy the zinc particle to the surface. This action went The next problem was to apply the principle on a commercial scale, and this involved much experiment and developmental work. Various kinds of sloping copper pans with gas jets below to maintain the tem-perature were first tried, but were found too slow and too costly in operation.

Jan 6, 1928

By J. M. Vetter, W. F. Bowman

The Gulf Coast area of Texas and Louisiana produced a total of 47,070,650 bbl. of oil during 1928, a decrease of 7,401,173 bbl. from the previous year. Of this amount Texas produced 39,353,950 bbl., or a decrease of 9,689,296 bbl. from the 1927 output. The Louisiana Gulf Coast produced 7,716,700 bbl., which is an increase of 2,288,123 bbl. over 1927. The decrease in the Texas Coastal area is due principally to the decline at Spindletop. Production at the beginning of the year in this field averaged 53,400 bbl. daily. At the end it had declined to 35,850 bbl. The increase in Louisiana was due to development in new fields at Kelso Bayou (East Hackberry), Sulphur, Sweet Lake, Bayou Boullion and Sorrento. This production was maintained by the drilling of 984 wells. Of this number 736 were located in Texas and 248 in Louisiana. Of the 984 wells drilled, 571 were reported as producers. Distribution of the various completions is listed in the accompanying tables compiled by Oil Weekly. New Developments New developments of particular importance in Texas were the finding of a 5000-bbl. well in formations of Cook Mountain age in the Clay Creek field located in northern Washington County by the Sun Oil Co. ; the discovery of oil at Dewalt in Fort Bend County by the Humble Oil & Refining Co.; the development of commercial production at Raccoon Bend in Austin County by the same company; and the finding of oil in formations of Oligocene age in the Refugio gas field of Refugio County. The most important development in Louisiana was the finding of oil at Sorrento, east of the Mississippi River, by the Gulf Production Co. The importance connected with these finds is not so great in that they opened up new fields, but in the new territories which they open as possibly productive of oil. Eastern Louisiana has been looked upon with considerable doubt on account of the theory which has prevailed among most geologists that the nature of the formations was not such as to produce oil. The actual finding of oil in that area upsets this theory and

Jan 1, 1929

By K. N. Bolatbaev, S. S. Naboichenko

The initial rates of dissolution of pyrite, chalcosine, sphalerite and galena in acidic sulphate solutions under oxygen pressure were measured in the range of Poe = 0.2-1 MPa, 130-180 °C, [H2SO4]0 = 0.2-0.7 M, and in the presence of surface-active agents and agitation producing Re = 4-16 x 103. Reaction orders, activation energies, and values of reaction constants for these oxidation reactions were established. The reactions also were shown to be diffusion-controlled; and the rates demonstrate a linear dependence on the surface area of the sulphides. A surface reaction model, in which oxygen is transported through a solid layer of surface products, has been advanced. The initial stage of high-temperature interaction at pH <7 is suggested to involve a chemical activation of the sulphide surface and is described by the following general reaction: MenSm + H3O+ Men-1 Sm-1 (HS-)s + H2O The subsequent oxidation of surface complex HS- to S0 or SO2-4 occurs with the assistance of Fe(III), Cu(II) ions depending on temperature and the redox potential of the medium, which are defined by oxygen pressure and composition of the reaction mixture, especially concentrations of H2SO4 and metals with variable valence. General process kinetics are complicated due to the formation of by-products on the basis of Fe3+ Pb2+, Cup ions, which displace the kinetics into the diffusion region.

Jan 1, 2004

By R. K. K. Mbaya

The concept of adsorption or separation of platinum anions from base metal cations in chloride media using native or chemically modified activated carbons has been discussed in various journals within the context of batchwise systems. In our research work, a fixed-bed column, loaded with native and amine-immobilized activated carbon pellets (Norit RO 0.8), was used to study selective adsorption of platinum ions from chloride media at different flow rates, bed depth and initial metal concentrations. The kinetics, mass transfer characteristics, breakthrough data and separation factors (ß(Pt/Fe) and ß(Pt/Cr)) were quantitatively analysed and modeled. The bed-depth service time (BDST) model was used to model the breakthrough curves successfully in fixed-bed columns and also the dispersive diffusion in the radial and axial directions of the bed were evaluated. The inner diameter of the column was 3 cm and the bed depth was between 1.0 cm and 2.5 cm. Concentrated 4 M HCl acid solution was used to elute the fixed-bed column. It was demonstrated that amine-treated activated carbons provides superior separation factors between platinum and base metals (Fe, Cr). Results showed also, that 95% saturation was reached within 10~26 hours depending on the nature of ACs at a flow rate of 11 mL/min and initial concentration of 5 ppm.

Jan 1, 2014

By Carl Rampacek, W. A. McKinney

The feasibility of leaching calcareous and siliceous oxidized copper ores by downward percolation with dilute acid was investigated in the laboratory and in a small continuous plant operated by the Federal Bureau of Mines . The crushed ore was leached in deep columns with solutions containing 1 or 5 percent sulfuric acid to dissolve the oxidized copper . Bench - scale laboratory tests on two calcareous ores from the same deposit indicated that a maximum copper extraction , about 72 percent , could be expected from heap leaching a feed as coarse as 1 inch . Laboratory tests on a siliceous ore showed that almost 70 percent of the copper could be extracted by leaching a 1 / 4 - inch feed . The bench - scale tests were supplemented by larger continuous runs wherein the copper was recovered from the leach liquors by precipitation on detinned scrap iron . Leaching the calcareous ore for approximately 10 days recovered 62 percent of the total copper . The sulfuric acid consumption was 9.6 pounds per pound of copper recovered . Treatment of the siliceous ore recovered 62.5 percent of the total copper in a 2.5 - day leach and the acid consumption was 3.7 pounds per pound of copper recovered . Cement copper products that assayed over 71 percent copper were obtained from the leach solutions by precipitation on scrap iron . The bench - scale and continuous tests demonstrated that downward percolation leaching of the calcareous ores was technically feasible but not economically practicable because of high acid consumption by the gangue . Leaching of the siliceous ore was rapid and the acid and water requirements were nominal . The downward percolation leach procedure is simple and requires a minimum of plant equipment .

Jul 1, 1960

By N. M. Langdon

ON account of its greater economy and cleanliness, and the extent to which iuferior fuels can be utilized for its generation, there has been of late a rapidly increasing tendency to substitute gaseous for solid fuel for metallurgical and other industrial purposes, which has led to various improvements both in the process and apparatus for its manufacture, notably among which may IN mentioned the Tessie Gas Producer* described by Mr. A. L. Holley. A considerable experience by the author with producers of various kinds using anthracite fuel, in connection with the Taylor ore-roast ing furnace at Chester, N. J., with more or less unsatisfactory resnlts, finally led to the erection of the experimental producer described below, which combines in its construction, simplicity, dorability, and accessibility for cleaning and removing the ash and manipulating the fuel. It is adapted to the use of various kinds of fuel, and is capa ble of generating a steady and uniform supply of gas at a minimum cost. It has been in constant use day and night for about five months, and has given very satisfactory results. The producer, as shown in the accompanying sketch, consists of a cylindrieal furnace, preferably inclosed in an iron jacket or casing, having a bosh or inverted cone-shaped base as in a blast furnace. It is provided with a bell and hopper, the bell being hung to a forked lever, and having guide flanges to prevent it from swing ing, and an opening at its apex through which to insert a bar for manipulating the fuel, which when not in use is closed with a plug or stopper. Cleaning is effected through two small doors placed opposite each other at the hearth level, which in order to facilitate the operation is elevated above the floor. The doors are removable, and when closed are by their own weight and by means of bevelled lugs held tightly against their frames, forming a practically tight joint. A blast of commingled steam and air is injected into the fuel through a series of tuyeres underneath the bosh communicating with steam jet injectors. A small flue also connects the door

Jan 1, 1884

By K. L. Komarek

Based on theoretical and experimental evidence a discussion follows of the behavior of phosphorus -bearing iron ores in the R-N Direct Reduction Process and suggestions are made of methods of reducing the amount of phosphorus in the metallic end product. In ferrous metallurgy a direct reduction process is one in which iron ores are reduced to metallic iron with gaseous or solid reductants without the appearance of a liquid phase. A number of attractive features have induced several companies and government agencies to invest in the development of direct reduction processes. A summary of all direct reduction processes up to 1954 has been given by Barrett,&apos; and Wiberg,2 and Willems3 have reviewed the most recent developments in this rapidly expanding field. Many difficulties have been encountered in direct reduction processes and the nature of these difficulties has varied from process to process. One problem common to almost all of them is the removal of phosphorus which is one of the reasons for the rather pessimistic outlook given by some government publications4&apos;5 to direct reduction processes. In this paper an attempt is made to give a theoretical explanation of the variations in phosphorus removal observed in the R-NY Direct Reduction Process. However, many conclusions are general enough to be applicable to other processes. Most iron ores treated by the R-N process yield products lower in phosphorus than the original ore. A qualitative account of the factors has been given by Stewart, Reed, and Herasymenkoe but the erratic removal of phosphorus from some ores and the general importance of this problem make a more careful analysis of the theoretical aspects desirable. In the R-N process mixed ore or balled fines, ex-

Jan 1, 1963