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By R. W. Ludt, C. C. DeWitt

The use of froth flotation for the separation of minerals has become one of the most important of ore dressing processes. Its particular adaptability to the enrichment of low grade ores has made the process an important factor in the national economy. The methods have been extended to the recovery of a great number of minerals. Among the few minerals which have resisted efforts toward industrial flotation is chrysocolla, a hydrated partly colloidal copper silicate. Chrysocolla, being a product of natural oxidation, has been found to occur in small quantities with many ores which are recovered by flotation methods. In present practice, these small quantities of copper silicate pass off with the tailings and are lost. The advantages to be gained by a satisfactory process for the recovery of chrysocolla is apparent. Any application of principles which points a way toward the satisfactory industrial flotation process for copper silicate would be of advantage. This paper presents an attack on this problem. Two methods for the recovery of chrysocolla have been developed by the United States Bureau of Mines.1,2 They have been successful on a laboratory scale but have been seriously restricted in industrial application by critical requirements in the procedure. In one of the Bureau of Mines methods,' the ore is activated with sodium or hydrogen sulphide in an aqueous solution at a pH of 4. Amy1 xanthate is then used as a collector with pine oil as a frother in the flotation process. An excess of sulphide acts as a depressant and the state of optimum conditions is difficult to control industrially. In the second Bureau of Mines method,2 soap is used as the collector at a pH of between 8 and 9. The diffi- culties with this process are that soap is not a specific collector, that heavy metal or alkaline earth ions cause the formation of insoluble soaps, and that a more acid solution causes the formation of a free acid which does not act as a collector for chrysocolla. The problem of recovering chrysocolla by flotation involves the selection of a suitable collector. The collector molecule must be composed of an active polar group that has an attraction for chrysocolla, and of a hydrocarbon chain. Certain dyes have been shown to have an attraction for certain minerals. Suida3 found that hydrated silicates are colored by basic dyes. Dittler4 showed that chrysocolla, among other colloidal minerals of acid reaction, preferentially takes up such basic dyes as fuchsin B, methylene blue, and methyl green. Endell5 gave information to show that the colloidal material in clay may be determined by its selective adsorption of fuchsin. A simple experiment, likewise, illustrates the difference in the adsorptive power of chrysocolla and of silica for the basic triphenyl methane dyes. When a mixture of chrysocolla and silica is immersed in a very dilute dye solution, less than 5 ppm, the chryso-colla is rapidly dyed and the silica is dyed more slowly. The difference is substantial but one of degree. Dean2 showed that the dyes, crystal violet and toluidine blue, are taken up by quartz in an adsorption type process. The difference in the adsorptive power, however, offers the means by which a new collector may act. To form such a collector, a hydrocarbon chain must be attached to the dye molecule. This involves a process of organic synthesis. Butyl, hexyl, and octyl hydrocarbon chains were selected for substitution in the malachite green molecule. For the purpose of identification, the alkyl-substituted dyes formed are called: butyl-malachite green; hexyl- malachite green; and octyl-malachite green. An outline of the procedure for their synthesis is given in the appendix. It is generally recognized in the preparation of this type of dye that the chemical structure of some of the dye molecules varies. However, a uniform formula is attributed to the dye. Such a procedure has been followed in specifying the structure of these alkyl-substi-tuted malachite green dyes. The structure is given on the basis of their properties as an homologous series of dyes, on their method of preparation, and on the purity of intermediates used. Structure of substituted alkyl malachite green is: C6H4 N(CH3)2 p-R C6H4 CH C6H4 N(CH)2 Procedure The flotation cell is a Bureau of Mines 100-g, batch unit provided with an air inlet at the bottom above which is a variable speed agitator. The agi-

Jan 1, 1950

By Shiou-Chuan Sun, R. E. Zimmerman

An evaluation of the mechanism surrounding the froth flotation of coarse coal and mineral particles as a result of experiments conducted at The Pennsylvania State College. Maximum size ranges for both bituminous and anthracite coals were established as well as the factors affecting the floating of coarse particles. CONSIDERABLE interest is developing in the froth flotation of coal and the maximum particle sizes which can be treated by such method. The economic necessity of recovering extreme coal fines and slurries plus the restrictions being placed upon stream pollution have brought about many new and prospective installations of flotation plants. Most coal slurries or silts have a wide size range, some sizes of which may be unsuitable for effective froth flotation. This fact also enters into the froth flotation of other minerals and the principles that SHIOU-CHUAN SUN and R. E. ZIMMERMAN, Members AIME, are Assistant Professor and Division Chief, respectively, Division of Mineral Preparation, The Pennsylvania State College, State College, Pa. Joint AIME-ASME Fuels Conference, French Lick, October 1949. TP 2843 F. Disccussion (2 copies) may be sent to Transactions AIME before June 30, 1950. Manuscript received Sept. 12, 1949. apply to coal would also apply to minerals in general. A series of experiments were made by the authors for the purpose of investigating factors influencing the froth flotation of coarse mineral particles and an attempt has been made to evaluate those factors. This paper presents the results of a study of the froth flotation of coal particles in the size range greater than 35 mesh. During the study a "multi-bubble" hypothesis has been developed to explain the various phenomena observed in the behavior of coarse particles in froth flotation of coal. The terms coarse, intermediate, and fine particles as used in this paper are arbitrary and differ for various minerals. For coal alone the term intermediate particles means that the particle size is within the range of 35 and 200 mesh of Tyler sieve sizes. Sizes of coal particles coarser and finer than this size range are termed respectively as coarse and fine particles. Methods of Conducting Flotation Experiments: All of the flotation tests, except those shown in table 1, were carried out in a laboratory Fagergren flotation machine, using 300-a samples of solids for each test. All mineral samples we; prepared from selected lumps of high purity by crushing, grinding, and screening to the desired sizes. Except coals, all the other samples were cleaned through magnetic

Jan 1, 1951

By R. E. Zimmerman, Shiou-Chuan Sun

An evaluation of the mechanism surrounding the froth flotation of coarse coal and mineral particles as a result of experiments conducted at The Pennsylvania State College. Maximum size ranges for both bituminous and anthracite coals were established as well as the factors affecting the floating of coarse particles. CONSIDERABLE interest is developing in the froth flotation of coal and the maximum particle sizes which can be treated by such method. The economic necessity of recovering extreme coal fines and slurries plus the restrictions being placed upon stream pollution have brought about many new and prospective installations of flotation plants. Most coal slurries or silts have a wide size range, some sizes of which may be unsuitable for effective froth flotation. This fact also enters into the froth flotation of other minerals and the principles that SHIOU-CHUAN SUN and R. E. ZIMMERMAN, Members AIME, are Assistant Professor and Division Chief, respectively, Division of Mineral Preparation, The Pennsylvania State College, State College, Pa. Joint AIME-ASME Fuels Conference, French Lick, October 1949. TP 2843 F. Disccussion (2 copies) may be sent to Transactions AIME before June 30, 1950. Manuscript received Sept. 12, 1949. apply to coal would also apply to minerals in general. A series of experiments were made by the authors for the purpose of investigating factors influencing the froth flotation of coarse mineral particles and an attempt has been made to evaluate those factors. This paper presents the results of a study of the froth flotation of coal particles in the size range greater than 35 mesh. During the study a "multi-bubble" hypothesis has been developed to explain the various phenomena observed in the behavior of coarse particles in froth flotation of coal. The terms coarse, intermediate, and fine particles as used in this paper are arbitrary and differ for various minerals. For coal alone the term intermediate particles means that the particle size is within the range of 35 and 200 mesh of Tyler sieve sizes. Sizes of coal particles coarser and finer than this size range are termed respectively as coarse and fine particles. Methods of Conducting Flotation Experiments: All of the flotation tests, except those shown in table 1, were carried out in a laboratory Fagergren flotation machine, using 300-a samples of solids for each test. All mineral samples we; prepared from selected lumps of high purity by crushing, grinding, and screening to the desired sizes. Except coals, all the other samples were cleaned through magnetic

Jan 1, 1951

By W. G. Wender

The North Central Texas district, as known to the oil fraternity, is the area producing from sands and limes of Pennsylvanian age, roughly embracing the territory lying between Fort Worth and Abilene in an east-west line, and between the Red River and the Llano Mountains in a north-south line. The history of oil development in North Central Texas during the year 1927 is briefly reviewed in the following paragraphs. Brown County New discoveries and development in Brown County centered mainly around the Fry pool, located in the west central portion of the county. Important discoveries for the year were: Shoupe No. 1 John Byler, discovery well of the Byler pool, located 2 miles south of the Fry pool which camc in early in February, 1927, at 1262 ft. for 90 bbl. in the Fry sand of upper Strawn (Pennsylvanian) age. Rosenfield No. 1 P. Davis, discovery well of the Smith-Ellis pool located 1 1/2 miles northeast of the Fry pool, came in March 7, in the Fry sand from 1277 to 1279 ft. for 30 bbl. initial. Pandem Oil Corpn. No. 1 Mrs. T. Hutton, located 1 mile east of the Smith-Ellis pool, came in in December in the Fry sand from 1119 to 1130 ft. for 45 barrels. The Fry pool passed its daily production peak of 25,000 bbl. during the first part of June, and declined to a daily production of 5100 hhl. by the close of the year. The oil recovery from the Fry pool up to Jan. 1, 1928, slightly exceeded 4,000,000 bbl., averaging 4700 bbl. to the acre. over the entire pool. The Smith-Ellis pool passed its daily production peak of 5300 bbl. in Octohcr, 1927, and dropped to 3600 bbl. by the close of the year. The possibilities of the Byler pool will be unknown until the area is fully drilled up. In the Blake pool, production passed 2,500,-000 bbl. for the year. The per acre recovery in this pool up to lkc. 31, averaged slightly over 5000 barrels.

Jan 1, 1928

By O. N. Carlson, H. A. Wilhelm, J. M. Dickinson

On the basis of microscopic studies, melting-point observations, and X-ray analyses, a phase diagram is proposed for the Cb-V system. A complete series of solid solutions is formed with a minimum in the solidus at 1810°C near 35 wt pct Cb. No compounds or intermediate phases were found in the system above 650°C. THERE is an ever increasing need for better structural metals and alloys for use in nuclear reactors. In addition to the normal properties of engineering structural materials, such as high temperature strength, resistance to corrosion, and fabric-abil~ty, the nuclear properties of the material must be considered. In a nuclear reactor it is important to conserve neutrons, so a material which removes these neutrons from the reaction excessively is considered to have unfavorable nuclear properties. In nuclear-reactor design the engineer must have nuclear as well as other data available on alloys in order to make a wise selection of materials. Due to the fact that many of the common structural materials have undesirable nuclear properties, it is vital that new alloys of metals having more favorable nuclear properties be investigated. Columbium and vanadium are both high melting metals, both exhibit resistance to chemical attack, and no great difficulty is encountered in fabricating them into desired shapes. With proper treatment both metals can be cold rolled extensively without failure. In addition they have desirable nuclear properties for certain types of reactors. Therefore, the alloys of columbium and vanadium should be of interest in the atomic energy program. Since an alloy-development program is enhanced by a knowledge of the phase equilibria of the components, this investigation was undertaken to establish the phase diagram for the Cb-V system. According to the Hume-Rothery rules for alloying,' the chemical similarity, crystal structure, and atomic-size factor are favorable for a complete series of solid solutions for this system. Both elements are in the same family of group V of the periodic table and thus are quite similar chemically. The crystal structures of columbium and vanadium are compatible for extensive solid solubility, since both have body-centered-cubic structures. The atomic diameters of columbium and vanadium are 2.85 and 2.62Å, respectively. This difference of slightly more than 8 pct is well within the 15 pct maximum difference allowed for extensive solid solubility. Experimental Procedures Source of Materials: Columbium powder and sheet trimmings were obtained from the Fansteel Metallurgical Corp. According to the manufacturer the metal contains less than 1 pct impurity. An analysis of the metal showed approximately 1800 ppm C in the powder while the sheet trimmings contained less than 500 ppm C. Spectrographic analysis showed minor amounts of Ca, Cr, Fe, Mn, Si, Ti, V, and Zr in both forms of the columbium. No commercial source of vanadium having the ductility and purity desired was available to the authors at the beginning of this investigation. As a result, all of the vanadium used in this study was prepared by the bomb reduction of vanadium pen-toxide with calcium employing the method reported by Long.' Yields of massive vanadium normally were about 80 pct. Chemical analysis of the vanadium prepared in this manner showed the presence of 200 to 500 ppm N and 800 to 1000 ppm C. Minor amounts of Ca, Fe, Mn, Si, Zr, Cr, and Cb were detected by spectrographic analysis. This vanadium metal was ductile and was cold rolled into 5 mil sheet. Annealing was not necessary during this rolling and the metal retained its cold-rolling characteristic after are-melting. Preparation of Alloys: The Cb-V alloys were prepared by melting pieces of vanadium sheet togethel-with columbium in the form of sheet or pellets of powder. The melting was carried out under argon in conventional arc-melting equipment employing a tungsten electrode and a water-cooled copper crucible. Each alloy was remelted three or four times, inverting the alloy after each melting in order to assure complete mixing. Alloys normally were obtained as round flat disks, weighed approximately 70 grams, and had roughly the shape of a disk 1 1/2 in. in diameter and 1/4 in. thick. Half of each alloy

Jan 1, 1955

By A. H. Geisler, J. H. Keeler

Preferred orientations in unalloyed zirconium were determined by the Geiger-counter spectrometer X-ray diffraction technique. With increasing P-annealing temperature the following textures were obtained: l—a retained a-annealing texture, 2—additional orientations predictable from the a-p (Burgers) relationship, and 3—a texture derived from a cube texture in the p phase. Earlier work on cold-worked and a-annealed zirconium was reappraised to show a quantitative dependence of rotations on temperature and to identify spurious areas of some of the pole figures. IN a previous paper,' the preferred orientations of high purity zirconium sheet were described for cold-rolled and annealed samples. Annealing temperatures up to 900°C, which is slightly above the allotropic transformation temperature, were explored. Of interest was the observation that the orientation of the hexagonal-close-packed material after annealing in the temperature range of the stable body-centered-cubic phase was similar to that of the material which had been annealed in the a temperature region, although a change in texture would be expected because of the many new orientations based on an orientation relationship between the two forms of zirconium. The reversion to an original orientation after an allotropic transformation cycle is not unusual. It has been found for titanium,"* for thallium," and for cobaltB among the hexagonal metals. Burgers found in his original work7 that, when zirconium was cooled through the allotropic transformation and then reheated, the body-centered-cubic phase reverted to the original orientation. Additional experimental work has been carried out to further explore the textures of zirconium after annealing in the temperature range above the allotropic transformation. In addition, a reappraisal was made of the earlier results for zirconium' in light of recent work on titanium4 which has shown that the texture type depends quantitatively on the temperature of annealing and that spurious areas may be encountered in the pole figures of hexagonal metals determined by the X-ray spectrogoniometer technique of analysis. Experimental Procedure Crystal-bar zirconium prepared by the iodide process was the material used in this investigation. The major impurity was hafnium which was less than 0.3 pct. The composition obtained by spectro-graphic analysis is given in Table I. Cold-rolled specimens were prepared from crystal bar by a series of reductions of approximately 0.010 in. until the sheet reached a thickness of 0.010 in., after which it was cold rolled to 0.001 in. thickness between sheets of alloy steel. The total cold reduction amounted to about 99.8 pct. Specimens were annealed for % hr at 1000" to 1100" to 1200°C or 1 hr at 1400°C in an evacuated Vycor or quartz tube. The transmission pole figures were obtained by

Jan 1, 1956

The work of the Committee on Industrial Preparedness* is well summed up in the following letter written by Thomas A. Edison, Chair-man of the Naval Consulting Board, after President Wilson and signed the army appropriation and army reorganization bills: "The Committee on Industrial Preparedness of the Naval Consulting Board, of which committee Howard E. Coffin is chairman, after a five months' campaign in many ways unique in vigor and vision has played a very definite part in the measures for the national defense which have just become law. It is responsible for having laid the foundation for a true industrial preparedness in this nation. "Five months ago the committee, wholly non-partisan in make-up, acting with the civil, mechanical, mining and electrical engineers and the chemists of the country, members of five great scientific bodies, began its work in' every nook and cranny of the land. The purpose was to prepare American industry efficiently to support the armed forces of America in the event of war. "The public, the business men and the legislators at Washington knew little regarding the demands on industry in connection with modern war. No department at Washington was charged with the duty of coordinating the needs of the army and navy with transportation, industry, and kindred functions. The purchasing, quartermaster's and ordnance departments of the army and navy were unable to buy military supplies except by competitive offering in the open market. No one had considered the need, and no legislative machinery was in existence, for preventing the presence of skilled workers on the fighting front when they would in time of war be needed in the factories, mills and mines of the country. Neither at Washington or elsewhere was there even a list of the industrial resources of the nation in such shape as could be used for practical purposes in case war should come. "The three things, then, that the committee headed by Mr. Coffin set out to do and that now have been brought about were as follows: First, to mobilize concretely the business men of America and their output against a day of need. This meant chiefly to discover in fullest detail just what equipment our manufacturers possessed that might be swung over to supply the army and navy swiftly and bountifully from the hour the colors were raised. In a few weeks this initial task, which has been a truly colossal one, will be at an end. A complete report of the equipment of practically every concern of substantial size in the country is now in the hands of the - committee. Directly in charge of the great inventory has been W. S. Gifford, Supervising Director of the Committee. The second step was to procure legislation making possible the placing by the war and navy departments of annual orders for munitions in small quantities to American manufacturers now not producing such things, so that quietly, efficiently and thoroughly they could learn in time of peace how to supply the government in time of war. The new laws make all this possible. It should be said here that this practice will bring about a geographical diffusion of munition plants all over our country, instead of affording us only a few such concerns for the most part near the exposed seaboards, as at present. It is obvious that this system will also throttle all talk of a munitions trust.

Jan 10, 1916

By P. E. Busby, C. Wells

FURTHER study of data used in determinations of 1—rates of diffusion of boron in austenite and 2—solubilities of boron in the a and phases of iron and steel' has provided an equation for the diffusion of boron in a iron. In brief, the previously published data were accumulated from the results of deboron-izing (and decarburizing) experiments carried out in the range of 700° to 1300°C. Diffusion coefficients (D?) for boron in austenite were calculated using the Grube solution of Fick's law. However, only solubility values were estimated from the discontinuous concentration-penetration curves, Fig. 1, which are characteristic of diffusion in two phases. Dr. Carl Wagner' has recently provided a solution for calculating D values from penetration curves of this type as follows: Cl1.1 —C8/C8- C11.1 = vp ? e ? erf (?) and D = ?/4?2 t where C11,12, C8, C11, and E have the values shown in Fig. 1. D is the diffusion coefficient, sq cm per sec; t is time of deboronizing anneal, see; and ? is a di-mensionless parameter. For a given diffusion experiment, the value of ? can be readily obtained by graphical solution from a plot of y vs the right-hand part of Eq. 1. D may then be evaluated from Eq. 2. The avplication of this solution to previously re-ported results, of which excerpts are given in Table I, permits the calculation of diffusion coefficients for boron in a iron. On the basis of these meager data, it is tentatively concluded that the diffusion of boron in a may be represented by the equation Da = 1011 e-92,900/RT where R is the gas constant, cal X 0C-1 X mol-1; and T is the absolute temperature, OK. Although the frequency factor, 106 sq cm per sec, is admittedly several orders of magnitude higher than expected, the value of Q, 62,000 cal per mol, appears reasonable and is, in fact, very similar to that for the self-diffusion of iron. It is pertinent to mention at this point that the value of Q obtained for the diffusion of boron in austenite by means of the Wagner solution is 19,000 cal per mol and is in excellent agreement with the value previously reported1 in the equation DT = 2xl0-3 e-21,000/RT [4] which was determined by the application of the Grube solution to other data. The fact that determined constants A and Q in the equation D? = A e-Q/RT were practically the same, independent of whether the Wagner or Grube solutions were used in determinations of D values, strengthened the authors' belief that the computed values of D (Table I) using the Wagner solution are reliable. The relative values in Eqs. 3 and 4 for the diffusion of boron in the a and ? phases, respectively, suggest that boron forms a substitutional solid solution in a iron and an interstitial solid solution in ? iron. The same tentative conclusion has been reached by McBride et al.3 on the basis of relative solubilities, atom diameter, and the size of the interstitial hole in a and ? iron. In connection with the data for test 14 listed in Table I, it is of interest to calculate the solubility of boron in a iron using the D value given by Eq. 3. As might be anticipated from the small movement of the interface in test 14, proper substitutions in Eqs. 2 and 1 give a low value, approximately 0.0004 pct B, at 850°C. Apparently at 835°C (test 13) it is possible to obtain 0.0018 pct B, and at 850°C only 0.0004 pct B into solution in the a phase before a second phase appears. These observations are consistent with the Fe-B constitution diagram proposed by McBride, Spretnak, and Speiser.3 References P. E. Busby, M. E. Warga, and C. Wells: Diffusion and Solubility of Boron in Iron and Steel. Trans. AIME (1953) 197, p. 1463; Journal of Metals (November 1953). 'W. Jost: Diffusion in Solids, Liquids, Gases. (1952) pp. 69-71. New York. Academic Press Inc. "C. C. McBride, J. W. Spretnak, and R. Speiser: A Study of the Fe-Fe2B System. Trans. ASM (1954) 46, p. 499.

Jan 1, 1955

By William P. Jones

THE consumption of sulphuric acid, one of the most important commodities in our modern industrial world, is often used as a barometer for industrial activity. The economics of acid manufacture are largely dependent upon the location of the place of consumption and the availability of raw materials in that locality. Sulphuric acid is made from SO,, oxygen from the air and water. Therefore the sulphur dioxide is the only raw material to be considered in an economic study. SO, can be obtained from almost any material containing inorganic sulphur, such as elemental sulphur, pyrites, coal, sour gas and oil, metallurgical gases, waste gases, or gypsum and anhydrite. Many tons of acid can also be reclaimed by the recovery and concentration of spent acids. The aim of this paper is to present a guide to the economic aspects to be considered when the installation of an acid plant is contemplated. It must be remembered that 1 ton of elemental sulphur produces 3 tons of sulphuric acid and that the shipping of sulphuric acid by tank car is very costly. The size of the plant must also be given careful consideration. For instance, operation of a plant producing 5 tons of acid per day might be warranted in Brazil or Pakistan, whereas economics usually favor buying quantities up to 50 tons per day for use within the United States. Elemental sulphur, when available at the low price of 1M4 per lb delivered at an acid plant, has always been the raw material most frequently used for sulphuric acid. All conditions favor its use at this price. The so-called sulphur shortage has been the subject of so many technical papers, magazine articles, and newspaper items during the past y6ar that it hardly seems necessary to mention it again, but a very brief review of the matter will serve as a foundation for the discussion that follows. There is no shortage of sulphur. Only a shortage of low-cost Frasch-mined brimstone exists today. Other more expensive sulphur-bearing materials are plentiful, both in the United States and abroad. The low cost of Frasch-mined brimstone has discouraged the development of higher cost sources. However, the approaching depletion of Gulf Coast dome deposits and the greatly increased demand for sulphur here and abroad have made it necessary for industry to prepare for conversion to utilize sulphur in other forms. For future planning this situation must be considered permanent and not temporary. This conclusion is based on the fact that although sulphur demand will continue to rise, the production of Frasch-mined sulphur probably will not increase greatly beyond its present level of about 5,000,000 long tons per year. The International Materials Conference in Washington estimates 1952 requirements of the free world at nearly 7 million long tons; and the Defense Production Administration has recently set a new goal for 8,400,000 long tons annual domestic production by 1955. The total sulphur equivalent produced in this country in 1950 was 6 million tons. What, then, are the alternatives for the manufacture of the vital chemical, sulphuric acid? Today about 85 pct of this country's sulphur, and nearly 50 pct of the world supply, comes from our Gulf Coast salt domes and is extracted from the earth by Frasch's hot water process. The Gulf Coast salt dome deposits have been the most important known natural deposits in the world, producing 90 million tons of sulphur during the past 50 years. However, at the present rate of extraction these deposits cannot be expected to last indefinitely. Pyrites Pyrites are, and have been for many years, the source of more than 50 pct of the world's sulphur requirements. The principal use, of course, is in the manufacture of sulphuric acid. The use of pyrites in the United States has diminished greatly because of the availability of low cost native sulphur, but pyrites have continued a major source of sulphur in many other countries. The most available pyrites for use in this country are in the form of lump pyritic ore and in mill tailings from flotation of other minerals such as lead, zinc, copper, gold, and silver. An important factor, when the use of pyrites for acid manufacture is being considered, is the disposal of calcine. A ton of sulphuric acid requires approximately ton of high-grade pyrite and results in 1/2 ton of calcine. If the calcine is a fairly pure oxide, free of harmful impurities, it can be used, after sintering, in an iron blast furnace burden. Its value might be as high as 15d per unit of Fe at the blast furnace; or possibly $10.00 per ton of sinter, if it assays 65 pct Fe. This might result in a credit of $4.00 per ton of acid if the sintering plant and blast furnace are both located adjacent to the acid plant. On the other hand, several factors must be considered before this credit can be realized, i.e., freight to blast furnace, availability of sintering facilities, methods of eliminating impurities, and the removal of valuable metal values. In some locations it would be most economical to dump the calcines.

Jan 1, 1953

By William P. Jones

THE consumption of sulphuric acid, one of the most important commodities in our modern industrial world, is often used as a barometer for industrial activity. The economics of acid manufacture are largely dependent upon the location of the place of consumption and the availability of raw materials in that locality. Sulphuric acid is made from SO,, oxygen from the air and water. Therefore the sulphur dioxide is the only raw material to be considered in an economic study. SO, can be obtained from almost any material containing inorganic sulphur, such as elemental sulphur, pyrites, coal, sour gas and oil, metallurgical gases, waste gases, or gypsum and anhydrite. Many tons of acid can also be reclaimed by the recovery and concentration of spent acids. The aim of this paper is to present a guide to the economic aspects to be considered when the installation of an acid plant is contemplated. It must be remembered that 1 ton of elemental sulphur produces 3 tons of sulphuric acid and that the shipping of sulphuric acid by tank car is very costly. The size of the plant must also be given careful consideration. For instance, operation of a plant producing 5 tons of acid per day might be warranted in Brazil or Pakistan, whereas economics usually favor buying quantities up to 50 tons per day for use within the United States. Elemental sulphur, when available at the low price of 1M4 per lb delivered at an acid plant, has always been the raw material most frequently used for sulphuric acid. All conditions favor its use at this price. The so-called sulphur shortage has been the subject of so many technical papers, magazine articles, and newspaper items during the past y6ar that it hardly seems necessary to mention it again, but a very brief review of the matter will serve as a foundation for the discussion that follows. There is no shortage of sulphur. Only a shortage of low-cost Frasch-mined brimstone exists today. Other more expensive sulphur-bearing materials are plentiful, both in the United States and abroad. The low cost of Frasch-mined brimstone has discouraged the development of higher cost sources. However, the approaching depletion of Gulf Coast dome deposits and the greatly increased demand for sulphur here and abroad have made it necessary for industry to prepare for conversion to utilize sulphur in other forms. For future planning this situation must be considered permanent and not temporary. This conclusion is based on the fact that although sulphur demand will continue to rise, the production of Frasch-mined sulphur probably will not increase greatly beyond its present level of about 5,000,000 long tons per year. The International Materials Conference in Washington estimates 1952 requirements of the free world at nearly 7 million long tons; and the Defense Production Administration has recently set a new goal for 8,400,000 long tons annual domestic production by 1955. The total sulphur equivalent produced in this country in 1950 was 6 million tons. What, then, are the alternatives for the manufacture of the vital chemical, sulphuric acid? Today about 85 pct of this country's sulphur, and nearly 50 pct of the world supply, comes from our Gulf Coast salt domes and is extracted from the earth by Frasch's hot water process. The Gulf Coast salt dome deposits have been the most important known natural deposits in the world, producing 90 million tons of sulphur during the past 50 years. However, at the present rate of extraction these deposits cannot be expected to last indefinitely. Pyrites Pyrites are, and have been for many years, the source of more than 50 pct of the world's sulphur requirements. The principal use, of course, is in the manufacture of sulphuric acid. The use of pyrites in the United States has diminished greatly because of the availability of low cost native sulphur, but pyrites have continued a major source of sulphur in many other countries. The most available pyrites for use in this country are in the form of lump pyritic ore and in mill tailings from flotation of other minerals such as lead, zinc, copper, gold, and silver. An important factor, when the use of pyrites for acid manufacture is being considered, is the disposal of calcine. A ton of sulphuric acid requires approximately ton of high-grade pyrite and results in 1/2 ton of calcine. If the calcine is a fairly pure oxide, free of harmful impurities, it can be used, after sintering, in an iron blast furnace burden. Its value might be as high as 15d per unit of Fe at the blast furnace; or possibly $10.00 per ton of sinter, if it assays 65 pct Fe. This might result in a credit of $4.00 per ton of acid if the sintering plant and blast furnace are both located adjacent to the acid plant. On the other hand, several factors must be considered before this credit can be realized, i.e., freight to blast furnace, availability of sintering facilities, methods of eliminating impurities, and the removal of valuable metal values. In some locations it would be most economical to dump the calcines.

Jan 1, 1953

By James Douglas

American metallurgical inventions have not always been absolute metallurgical improvements, if accurate work be the standard of comparison; but when we review the new methods and machinery which have been generally accepted, we find that some have become essential to the metallurgist the world over, while all are so admirably adapted to the peculiar requirements of our local conditions that they have entirely supplanted foreign processes and appliances. The necessity of diminishing to the utmost the employment of labor (owing to its great cost), and the inexorable requirements of our modern joint-stock corporate system, which demands that large quantities be worked up in order to secure large returns, regardless betimes of waste, have been the impelling motives to invention, and indicate the special directions in which originality has been exercised. As might be anticipated, the West has been the most fertile field of inventions by miners and metallurgists, by reason of its great and varied mineral wealth, locked up in ores sometimes lean and often of intricate composition, which must be profitably handled, at a great distance from fuel and from building-materials, by workmen who are paid wages very much higher than those received by their fellow-workmen of like craft in Europe, and in some localities twice as high as those paid for like services even in the eastern States. Moreover, paradoxical as it may seem, the technical inexperience of many of those engaged in mining and metallurgy has helped rather than hindered the progress of invention; fop while there may have been ignorance, there has been radical freedom from

Jan 1, 1894

By W. B. Weeks, H. K. Shearer

The year 1937 brought to south Arkansas increased drilling activity and production. Oil production amounted to 12,159,440 bbl., an increase of 1,504,500 bbl., or 14.1 per cent over 1936. This was the largest production since 1931, and the first annual increase since 1925, when the deeper sands at Smackover were developed. There were 177 wells completed during the year, with 103 oil wells, 6 gas wells, and 68 dry holes, an increase of more than 100 per cent over 1936. Of the 56 wildcat wells drilled, 52 were dry and 4 produced oil. Two new fields, one important extension and three minor extensions were discovered. The trend toward deeper drilling is shown by the fact that 97 wells were more than 5000 ft. deep, including 80 over 6000 ft. and 13 over 7000 ft., although the depth record of 7973 ft., made in 1935, was not exceeded. Geological Section Deeper and more extensive drilling during the past few years, not only in south Arkansas but also in adjacent parts of north Louisiana and east Texas, has furnished much important geological information and has brought out some very unexpected facts in regard to structural and depositional conditions in the series of formations laid down in the interval between the end of the Pennsylvanian and early Cretaceous time. It is now evident that an important basin of salt deposition existed in the Arkansas-Louisiana-Texas area, but it is still an open question whether this salt basin was contemporaneous and continuous with the even larger Gulf Coast salt basin extending from Mississippi to Mexico. The accompanying columnar section (Fig. 1) shows the producing zones and names that have been applied to the several subsurface formations, most of which have no outcrop equivalents. This is for the convenience of readers unfamiliar with recent developments, but the correlations and nomenclature cannot yet be considered final. These formations will be discussed in more detail in various papers to be published in the near future.

Jan 1, 1938

By Elmer W. Pehrson

The term "survival" in the title means the preservation of a society in which men are free from the political and economic restraints that characterize totalitarian systems, be they communist, socialist or facist. It means the ability to withstand the enemy's offensives in the fields of propaganda, commercial competition and, if necessary, war. The temptation to substitute "victory" for "survival" is great but a realistic appraisal of the creeping socialism and demagoguery that pervade our time indicates that we may have to be content with survival in status quo. "Mineral strength" means assurance that adequate supplies will be available to meet all the contingencies of cold and hot wars. The overall mineral position of the U. S. viewed in the light of these premises is far from secure. It is true that we are the leading producing and consuming nation of the world, but the Soviet Union is gaining and the Sino-Soviet Bloc confronts us with a sobering potential. The emergence of the Common Market in Europe as an economic and political unit places a third independent entity into the competition. Our total mineral output continues on an up- ward trend but the reverse is true in certain strategic commodities. Moreover, consumption is moving ahead faster than production so that there is increasing dependence on imports which has significant adverse geopolitical connotations. There is widespread belief that our resources can at least maintain present levels of self-sufficiency during this critical period in world history, but social dreamers, the labor monopoly, and trade and taxation policies have discouraged aggressive activity in exploration and development, and access to essential foreign sources is threatened by a variety of circumstances. Our stockpiles, belatedly built up to achieve minimum protection against shortages in time of war, are under. political attack and threatened with partial destruction on the basis of what are at best uncertain assumptions regarding the new: look of global warfare.

Jan 11, 1962

E. L. BLOSSOM, New. York, N. Y.-That this paper deals with a real problem is illustrated by a statement made to the speaker a few months ago by the manager of a silver-lead property: "Our ore contains 60 per cent. silica on which the smelters are penalizing us heavily, and they are not able to take all our stuff even then. We have simply got to find some method other than smelting for getting the silver and lead out of our ores. We have had experts down here and have investigated flotation, leaching and volatilization, of which processes the latter is by far the most promising. We are continuing investigation." I was somewhat concerned in certain chloride volatilization experiments which we carried on in Denver in 1903, working on a carload of ore from Butte. Now being connected with the Cottrell process, by which method the fumes will undoubtedly he recovered if they solve the volatilization problem, I have looked into the matter again, and believe it can be developed into a commercial process. On a laboratory scale, working With silver-lead ores, experimenters have obtained a volatilization of over 90 per cent. of the total values in 30 to 60 min, on quantities of 1 to 5 lb., using a roasting dish and a muffle. That looks very good, and would be entirely commercial. On attempting to duplicate these results in a reverberatory furnace, they found that it is more likely to take 8 hr. firing to yield 75 per cent. extraction, which is not commercial at all, as it requires too much time, labor, and fuel, and the whole process is too slow. Of course it can be done, because we have done it in the laboratory.

Jan 1, 1918

By Francis Donaldson

THE direct injection of cement grout into water-bearing fissures as a means of checking or stopping the flow of water into shafts and tunnels has been experimented with for a decade or longer and seems to have been first attempted in Europe. The earliest application of which the writer has found a record was at a shaft sunk by the Mining Society of Lens; this is described by C. Dinoire in the Transactions of the Institution of Mining Engineers.1. It is only lately, however, that the process has been entirely successful. This success has been accomplished on the Catskill Aqueduct, now under construction by the city of New York. This aqueduct includes a number of deep pressure tunnels, reached by shafts for both waterway and construction purposes. In portions of these shafts and tunnels considerable underground water was met. The contract for the first of these deep pressure tunnels was let to the T. A. Gillespie Co.; this section is known as the Rondout Siphon. It leads under the Rondout valley at a depth of from 400 to 800 ft. and is about 5 miles long. The engineers expected that considerable water would be encountered, but fortunately this was not the case except at one shaft, known as No. 4, which penetrated the rock at a junction between limestone and conglomerate. Water-bearing fissures were encountered almost immediately. At a depth of about 200 ft. a flow of 1,500 gal. per minute was struck. The shaft then contained as many pumps as could be used, and it seemed impossible to sink it further. After vain efforts had been made to proceed, John P. Hogan, a division engineer of the Board of Water Supply, suggested that cementation of the fissures be tried. The process was attempted for the first time in this country. Since the shaft was partly full of water it was necessary to drill grout holes with a diamond drill. Platforms were placed on the timbers at the water level, the diamond drill was installed and six 90-ft. holes were drilled in the bottom of the shaft. Several car loads of cement were pumped through these holes into the fissures, the drill casings being used for grout pipes. This largely cut off the flow of water from the bottom and sinking could then

Jan 1, 1914

By B. W. Frazier

IN the numbers of the Engineering and Mining Journal of June 27th and July 11th, 1874, there appeared some very complete statistics of the working of some anthracite blast-furnaces belonging to a large establishment in this country, followed by calculations of the heat requirements of the furnaces, similar to those which have been made for European furnaces by Mr. I. Lowthian Bell, Prof. Gruner, Prof. Akerman and others. To the author of these valuable papers, Mr. John A. Church, of New York, the thanks of American iron metallurgists are due for this attempt (the first, to my knowledge at least), to attack systematically and scientifically the problem of economy of fuel in our anthracite blast-furnaces, by applying the formulas obtained from European practice and from the experiments of European metallurgists, to the determination of the amounts and the modes of distribution of the heat production and absorption in our furnaces. In order to facilitate a comparison of the results thus obtained for the anthracite furnaces in question with those obtained for the best types of European coke furnaces, I have reduced to the same standard of heat units (the product of the ton and the degree Centigrade), and placed side by side, the calculations of the heat requirements of one of the furnaces of the Clarence works, as given by Mr. Bell, of a furnace at Pouzin, on the banks of the Rhone, given by Prof. Gruner, and of the anthracite furnaces for 1869-73, as given -by Mr. Church. Table I shows the different conditions of working of the three furnaces, of which Table II gives the respective heat requirements. I have made this latter table in such a manner as to give for each furnace its heat requirements, both according to the views of Mr. Bell and those of Prof. Gruner. Mr. Bell assumes that all the carbonic acid produced by the decomposition of the carbonate of lime of the charge, is reduced to carbonic oxide by contact with solid carbon ; also, that the carbon of the pig iron is a portion of that deposited in the ore in the upper part of the furnace, by the dissociation of carbonic oxide. Prof. Gruner, on the other hand, assumes that all the carbonic acid of the carbonates of the charge escapes unreduced, and that the carbon deposited in the upper part of the furnace, by the dissocia¬tion of carbonic oxide, is again converted into carbonic oxide or

Jan 1, 1875

By B. W. Frazer

In the numbers of the Engineering and Mining Journal of June 27th and July llth, 1874, there appeared some very complete statistics of the working of some anthracite blast-furnaces belonging to a large establishment in this country, followed by calculations of the heat requirements of the furnaces, similar to those which have been made for European furnaces by Mr. I. Lowthian Bell, Prof. Gruner, Prof. Akerman and others. To the author of these valuable papers, Mr. John A. Church, of New York, the thanks of American iron metallurgists are due for this attempt (the first, to my knowledge at least), to attack systematically and scientifically the problem of economy of fuel in our anthracite blast-furnaces, by applying the formulas obtained from European practice and from the experiments of European metallurgists, to the determination of the amounts and the modes of distribution of the heat production and absorption in our furnaces. In order to facilitate a comparison of the results thus obtained for the anthracite furnaces in question with those obtained for the best types of European coke furnaces, I have reduced 60 the same standad of heat units (the product of the ton and the degree Centigrade), and placed side by side, the calculations of the heat requirements of one of the furnaces of the Clarence works, as given by Mr. Bell, of a furnace at Pouzin, on the banks of the Rhone, given by Prof. Gruner, and of the anthracite furnaces for 1869-73, as given by Mr. Church. Table I shows the different conditions of working of the three furnaces, of which Table II gives the respective heat requirements. I have made this latter table in such a manner as to give for each furnace its heat requirements, both according to the views of Mr. Bell and those of Prof. Gruner. Mr. Bell assumes that all the carbonic acid produced by the decomposition of the carbonate of lime of the charge, is reduced to carbonic oxide by contact with solid carbon ; also, that the carbon of t,he pig iron is a portion of that deposited in the ore in the upper part of the furnace, by the dissociation of carbonic oxide. Prof. Gruner, on the other hand, assumes that all the carbonic acid of the carbonates of the charge escapes unreduced, and that the carbon deposited in the upper part. of the furnace, by the dissociation of carbonic oxide, is again converted into carbonic oxide or

By C. H. Bushell, M. Malnarich

REAGENT control in flotation is more an art than a science. Operators vary the amount of reagents used according to the metallurgy obtained. The amount of collector may be increased, for example, if tailings losses are high and decreased if concentrate grades are low. Often control decisions are based on only one assay, such as the tailings analysis by microscopic or quick assaying techniques. This method of control has given reasonably satisfactory results but is clearly far from perfect. No adjustment in reagent addition can be made until information is received that metallurgy has deteriorated, that is, until the optimum time for adjustment has already passed. The first adjustment probably will be an overcorrection or an undercor-rection, and time will be required to establish the best new addition rates. The seriousness of the problem depends on variability of the ore. In ore of continually shifting composition and complexity, mill results will shift back and forth from excessively high concentrate grades and high tailings losses to excessively low concentrate grades and low tailings losses. Economic incentive for improved control also increases with increasing size of mill. Even a small improvement in percentage recovery in a large mill pays for expensive control equipment. The Sullivan concentrator of The Consolidated Mining & Smelting Co. of Canada Ltd. at Kimberley, B. C., treats 11,000 tpd of complex lead-zinc ore, a scale of operations which justifies an extensive research program on automatic control. Work has followed two separate lines: 1) development of faster analytical methods for pulps, and 2) study of metallurgical control by measurement and control of reagent concentrations in flotation solutions. Although work is incomplete in both phases, a progress report can be given on the development of reagent control. The primary requirement in flotation is selective attachment of particles of one mineral to air bubbles while the other minerals remain detached. Hydrophobicity of mineral surfaces is established by the collector, which coats the minerals by adsorption. The requirement of selective affinity for air bubbles is therefore equivalent to requiring selective adsorption of a collector. Adsorption theory, supported by abundant experimental evidence, shows that the amount of a reagent adsorbed at a surface must be a function of its residual concentration in solution. As the concentration in solution rises, the amount adsorbed increases, usually following some type of logarithmic curve. Selective adsorption must depend on a natural difference in the minerals, but ordinarily the differences in affinity are not great enough to obtain complete coverage of one mineral while the others are completely uncoated. An optimum concentration will exist, below which coverage will not be great enough to float enough of the valuable mineral, and above which too much unwanted mineral will float. All other reagents, except some frothers, affect the amount of collector adsorbing at constant residual collector concentration in solution, either by adsorbing competitively with the collector, or by a

Jan 1, 1957

By Neil O. Johnson

In the cyanidation of gold, silver and mixed ores, the solids, suspended in the pulp after fine grinding, primary settling and scries agitation arc subjected to a washing step known, generally, as countercurrent decanta-tion, abbreviated C.C.D The conventional C.C.D. plant consists of a series of separate thickeners—three to five in number—arranged in series on slightly different elevations. Solids settled in the first thickener are pumped at maximum density into the second thickener, where they arc diluted with weak solution overflowing the third. After settling in the second thickener they are pumped to the third, where the process of repulping with still weaker solution is repeated, and so on throughout the system, until they reach the last thickener and are repulped with barren solution or water. Recently there has been developed a new type of thickener, known as the Dorr Washing Tray Thickener, consisting of up to five individual thickeners, which performs in a single unit all the functions of a conven-tional C.C.D plant. Fig. 1 illustrates the essential features. It is a multicompartment tray thickener, in which the trays operate in scries instead of in parallel for countercurrent washing. Feed enters the top compartment via a central, semisubmerged feed well. Strong solution overflows into a peripheral launder. Solids settle to the bottom, are raked to the center and flow into the top of the second compartment, directly below, via an inverted cup and scal. Solids pass downward, compartment by compartment, against a counter flow of wash solution and finally of fresh water. Thus, in accord-:trice with the basic C.C.D. principle, the solids transfer the dissolved metal content to the wash solution and finally are removed by a diaphragm pump from the bottom compartment virtually free of valuable material. Similarly, the wash water, as it flows through the system, becomes increasingly enriched in dissolved metal until it overflows from compartment two and returns to the process.

Jan 1, 1939

By Neil O. Johnson

In the cyanidation of gold, silver and mixed ores, the solids, suspended in the pulp after fine grinding, primary settling and scries agitation arc subjected to a washing step known, generally, as countercurrent decanta-tion, abbreviated C.C.D The conventional C.C.D. plant consists of a series of separate thickeners—three to five in number—arranged in series on slightly different elevations. Solids settled in the first thickener are pumped at maximum density into the second thickener, where they arc diluted with weak solution overflowing the third. After settling in the second thickener they are pumped to the third, where the process of repulping with still weaker solution is repeated, and so on throughout the system, until they reach the last thickener and are repulped with barren solution or water. Recently there has been developed a new type of thickener, known as the Dorr Washing Tray Thickener, consisting of up to five individual thickeners, which performs in a single unit all the functions of a conven-tional C.C.D plant. Fig. 1 illustrates the essential features. It is a multicompartment tray thickener, in which the trays operate in scries instead of in parallel for countercurrent washing. Feed enters the top compartment via a central, semisubmerged feed well. Strong solution overflows into a peripheral launder. Solids settle to the bottom, are raked to the center and flow into the top of the second compartment, directly below, via an inverted cup and scal. Solids pass downward, compartment by compartment, against a counter flow of wash solution and finally of fresh water. Thus, in accord-:trice with the basic C.C.D. principle, the solids transfer the dissolved metal content to the wash solution and finally are removed by a diaphragm pump from the bottom compartment virtually free of valuable material. Similarly, the wash water, as it flows through the system, becomes increasingly enriched in dissolved metal until it overflows from compartment two and returns to the process.

Jan 1, 1939