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NEW MEMBERS The following list comprises the names of those-persons who became members during the month of January, 1914. Members ADIASSEWICH, ALEXANDER, Dept. of Commerce & Industry, 11, Nadejdinskaia, St. Petersburg, Russia. BEARD, JOHN W., Mine Supt., Lane-Rincon Mines, Inca, Temascaltepec, Mex., Mexico; BORCHERDT, WALTER 0., Supt The Bertha Mineral Co., Austinville, Va BREWSTER, BURT B., Sales Engr., Sullivan Machinery Co., 1127 Central National Bank Bldg., St. Louis, Mo: CHASE, ROGER E., JR., Assayer 3906 No. Baltimore St., Tacoma, Wash. CULBERT, J. VICTOR 7S4 Wellington St., London, Ont., Canada; DICKINSON, ALBERT W., Supt. Of Mines Bevier, MO. DODSON, T. M Mores, Colliery, Schuylkill Co., Pa FORREST, CHARLES N., Chem. Engr Maurer, N. J.

Jan 2, 1914

Discussion of the paper of WALTER 0. SNELLING, presented at the New York meeting, February, 1915, and printed in Bulletin No. 100, April, 1915, pp. 695 to 704. A. F. LUCAS, Washington, D. C.-Are the results of the experiments in practical operation? WALTER 0. SNELLING.-There have been no large-scale operations up to the present. The necessary conditions of temperature are easily arranged for, but the required condition of pressure, 800 lb., is not so simple a matter. The company has been working on this problem, and at the refinery in Oklahoma work of this kind is now being carried on. The way in which an ordinary still will leak at 50 lb., and more at 100 lb., leaves some doubt in the mind of many as to what can be clone at a continuous working pressure of 800 lb. On the other hand, the fact that they are making ammonia abroad by a method which employs higher pressures and temperatures than anything involved in this method, leads me to believe that the difficulties, which will undoubtedly arise when this is attempted on a commercial scale, can be overcome. WILLIAM N. BEST, New York, N. Y.-Is there any change in the calorific value of these oils?

Jan 5, 1915

NEW MEMBERS The following list comprises the names of those persons who became members during the period Nov. 10 to Dec. 10, 1914: Members ABBOTT, Louis BENJAMIN, Chief Engr., Consolidation Coal Co., Elkhorn Div., Jenkins, Ky. ANDERSON, THORVALD J 542 S. Seventh Ave., Mt. Vernon, N. Y. BALFOUR, A. M P. 0. Box 301, Republic, Wash. BOUDWIN, WALKER J., Mech. Engr 159 Pierpont Ave., Salt Lake City, Utah. BRADLEY, LINN, Engr Research Corpn., 63 Wall St., New York, N. Y. BROKAW, ALBERT DUDLEY, Asst. Prof., Min. and Econ. Geol., Univ. of Chicago, Chicago, Ill. BUTLER, PERCIVAL PACE, Asst. Supt., Copper Queen Reduction Wks., Douglas, Ariz. CAJANDER, SVEN G., Mech. Engr Braden Copper .Co., Rancagua, Chile.

Jan 1, 1915

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman: PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS, Secretary, 55. Wall St., New York, N. Y. C. A. BOHN, Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane; Wash. STANLY A. EASTON, S. SHEDD.

Jan 1, 1917

NEW MEMBERS The following list comprises the names of those persons who became members during the period July 10 to Aug. 10, 1915: Members ALBERTSON, MAURICE MERTON, Mine Surveyor, Mining Corporation of Canada, Cobalt, Ont., Canada. ARMSTRONG, GEORGE CHANDLER Mgr., Indian Refining Co., Lawrenceville, Ill. BARBER, MAX HAYDEN, Min. Engr Supt., Crosby Mine, Nashwauk, Minn. BARNESON, JOHN Merchant, 310 Sansome St., San Francisco, Cal. BENSEL, JOHN A., Cons. Engr 111 Broadway, New York, N. Y . BORGESON, ANSHELM CYRUS, fin. Engr Shenango Mule, Chisholm, Minn. BROOKS, CHARLES PETER, Min. Engr 228 Dooly Bldg., Salt, Lake City, Utah. BROWN, FRANK HAROLD, U'011',. Min. Engr., Federal Co., Inc., 50 Broad St., New York, N. Y. CLARK, DOUGLAS Kellogg, Idaho.

Jan 9, 1915

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, Jr., Chairman EDGAR RICKARD; Vice-Chairman D. M LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BORN, Treasurer JOHN V. N. DORR - LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, -Mass. Inst. of Technology. Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND. Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. 0. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 1, 1918

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNS, Chairman. PERCY E. BARBOUR, Vice-Chairman A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman: E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON, S. SHEDD.

Jan 2, 1917

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. MI. LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BOHN, Treasurer JOHN V. N. DORR LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology. Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 8, 1917

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. M LIDDELL, Secretary, 7 Wall St., New. York, N. Y C. A. BOHN, Treasurer JOHN V. N. DORR _ LEWIS W FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman - JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. S. S. FOWLER, Chairman J. C. HAAS, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer. P. O. Drawer 2154, Spokane, Wash. W. H. LINNEY

Jan 2, 1918

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON, S. SHEDD.

Jan 3, 1917

By A. A. Bauer, F. A. Rough, G. H. Beatty

AS a result of recent studies, the constitution of the zirconium-uranium system has been fairly well defined. A diagram for the system is shown in Fig. 1. However, both oxygen and nitrogen are known1-3 to have a pronounced effect on the limits of both ß- and e -phase regions. It has been shown that small amounts of oxygen severely constrict the compositional limits of these phase regions in the ternary zirconium-uranium-oxygen system. A previously published tentative diagram shown in Fig. 2 illustrates the ß-phase constriction resulting from oxygen additions. Generally, iodide zirconium has been used in constitutional studies of zirconium-uranium alloys. While this is the highest purity material available, cast iodide zirconium-uranium alloys will generally average from 200 to 300 ppm 0 and from 50 to 60 ppm N. Thus, while the constitution of the zirconium-uranium system is fairly well defined, it must be realized that this definition applies to alloys containing in the vicinity of 250 ppm 0 and 50 ppm N. The present investigation was undertaken to accurately determine the boundary between the ß-plus-P and ß phases at a single temperature in the binary zirconium-uranium system by quantitatively

Jan 1, 1959

By G. M. Willis, F. L. Hennessy

The oxygen pressure in equilibrium with silver and Ag2O-B2O3 melts has been measured between 800' and 900°C, to obtain the thermodynamic properties of the liquid. The compound Ag20. 4B20:1 appears to exist in the liquid, which shows marked heat content and entropy effects. A KNOWLEDGE of the thermodynamic properties of binary liquid silicates, borates, and phosphates would be of considerable assistance in the interpretation of the behavior of multi-component metallurgical slags. However, the literature contains comparatively few studies of the thermodynamics of binary slags. The system Ag20-B,O, attracted our attention as it was known to give a single liquid phase,',' in which high contents of silver could be obtained (up to 61 pct Ag according to Foex2). Further, it would be expected that the partial pressure of oxygen over melts in equilibrium with metallic silver could be used to determine the activity of Ag2O in the Ag,O-B,O, system. In many respects, it may be expected that the reaction of a basic oxide with boric oxide would be analogous to its reaction with silica. Liquid immiscibility frequently occurs in both borate and silicate systems. With B2O3 and SiO reaction with a basic oxide presumably involves a breakdown of the three-dimensional network of the acid oxide by reaction with oxygen atoms common to more than one silicon or boron atom. Ag2O-B2O3 was therefore investigated as a model of a slag system in the hope that its thermodynamic properties would assist in understanding those of other systems. Several methods for determining the activity of a component in a slag have been described in the literature. Chang and Derge" used high temperature electromotive force measurements to obtain the activity of SiO2 in CaO-SiO2 and Ca0-Al203-Si02 slags, but the cell reaction in their work is not clear. low has used rate of volatilization and vapor pressure measurements combined with phase diagrams to obtain activities in the systems KO-SiO,, Na,O-SiO, and Li,O-SiO," and PbO-SiO26 Taylor and Chipman7 extrapolated their results for the distribution of FeO between liquid iron and CaO (+Mg0)-FeO-SiOl slags to obtain the activity of FeO in the binary FeO-SiO2 system. In principle, one of the most direct methods for obtaining the activity of a metallic oxide in a phase is by comparison of the equilibrium oxygen pressure for the system metal-pure oxide with that of metal oxide-containing phase. Schenck and othersa have studied the stabilization of Ag2O on combination with other oxides (MO,) in the solid state by measurements of the oxygen pressure in systems of the type Ag-Ag,O-xM0,-MOy-0, (gas). Schuhmann and Ensio" have determined the activity of FeO in iron silicate slags in equilibrium with solid iron, using CO/CO2 mixtures to establish known partial pressure of oxygen. Although the method gives the activity of FeO without ambiguity, the slag is not a binary system, and interpretation of the results in terms of the hypothetical binary system FeO-SiO, is not possible. If a metal is solid at temperatures at which the properties of the slag containing its oxide are to be studied, this method has the considerable experimental advantage that the metal can be used as the container for the slag, and contamination by contact with refractories is avoided. In this work, crucibles for Ag2-B,O, melts were made from silver, and the liquid brought to equilibrium with definite pressures of oxygen gas. The oxygen pressure PO, thus fixes the activity of Ag20 in the liquid silver borate. For the reaction at a given temperature. is substantially constant, is directly proportional to the square root of the equilibrium oxygen pressure. Varying the oxygen pressure changed the silver oxide content of the liquid and it was possible to obtain the activity of Ag2O over a range of composition. Experimental Procedure In principle, the method consisted of bringing melts in silver crucibles or boats to equilibrium at a fixed temperature under a definite pressure of oxygen and analyzing the glass after solidification. Materials: B2O3 glass was prepared from A.R. quality boric acid by fusion in platinum. The silver

Jan 1, 1954

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. M. LIDDELL, Secretary, 7 Wall St., New York, N. Y. JOHN V. N. DORR C. A. BOHN, Treasurer LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 9, 1917

AARONS, J. BOYD, Major. AGNEW, FRANK VANS. ALLEN, HERMAN H., Private, D Co., 8th Reserve -Engineers. AMBLER, HARRY A., Second Training Camp, Ft. Sheridan, Ill. BAINS, THOMAS M., JR., Major, Engineer Officers' Reserve Corps. BANKS, H. R., Lieutenant, Canadian Engineers, B. E. F. BARBOUR, PERCY E., Deputy Supt. (Captain), New York State Troopers; Captain, 22c1 Regiment, N. Y. N. G. BARLING, H. B., 1st Lieutenant, Engineer Officers' Reserve Corps. BARRETT, LESLIE P., Lieutenant, A. E. F., France. (Unattached.) BENSEL, J. A., Major, Engineers' Reserve Corps. BIGELOW, BRAXTON, Royal Engineers, B. E. F. BLOOMFIELD, E. C., Lieutenant. BORROW, F. K. BOWLES, MARTIN F., 2d Lieutenant of Infantry, Camp Funston, Kans.

Jan 10, 1917

(The following-list contains the names of those members of the Institute of whose connection with military service we have only recently. become acquainted.) ADAIR, ARTHUR C., Corporal, 4th Co., 1st Tr. Bn., 154th D. B., Camp Meade, Md. BATCHELOR, STILLMAN, 1st Lieut., Co. 6, E. 0. T. S., Camp Humphreys, Va. BATES, BENNETT R., 1st Lieut., Engineers, Co. 3, E. 0. T. S., Camp Humphreys, Va. BJORGE, GUY N., Co. 3, E. 0. T. S., Camp Humphreys, Va. BOAS, Ross, H., U. S. A. BRADLEY, . H., JR., Capt., 408th Engineers, Camp Cody, N. M. BRINTON, OWEN F., Capt., Engineers, U. S. A. BROWN, HAROLD C., 2d Lieut., A. S. A.P.

Jan 1, 1919

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and visitors who registered at Institute headquarters during November: George W. Otterson, Mauson, B. C. Roy H. Allen, Chihuahua, Mexico. E. L. C. Ayres, Bound, Brook, N. J. George A. Packard, Boston, Mass. M. Russell, Bound Brook, N. J. Richard C. Patterson, Jr., Kansas City,,Mo. Carlo Spruyt, Antwerp, Belgium. Francis C. Phillip, Pittsburg, Pa. Charles A. Pringle, San Francisco, Cal. M. H. Kuryla, Mexico City, Mexico. E. S. Bardwell, Great Falls, Mont. Arthur Chippendale, Mexico City, Mexico. Sir Robert Hadfield, London,, England. F. Danvers Power, Sydney, Australia. James A. Barr, San Francisco, Cal..

Jan 12, 1913

By Donald W. Gentry, John F. Abel

This paper presents some of the results of a rock mechanics instrumentation program designed for, and implemented at. longwall panel 4N at the York Canyon Mine near Raton, New Mexico. The objective of this particular instrumentation program was to determine the response of the rock mass to longwall mining of a thick coal seam utilizing shield-type supports. Measurements were made in the rock along the ground surface, above the coal seam, in the coal seam, and immediately below the coal seam. Longwall test panel 4N had a total developed length of 762 m (2500 ft) and a face width of 168 m (550 ft), [Fig. 1]. The seam mining height in the panel area was approximately 3 m (10 ft). The average depth of overburden above the panel is 107 m (350 ft) although it ranges from 73-134 m (240-440 ft). Roof support at the face was provided by 116 Hemscheidt 320 HSL shields. These shield-type supports weigh 11.4 metric tons each.

Jan 1, 1979

“The mining industry can do more to alleviate world poverty, hunger and human misery, more to close the widening gap between advanced and developing nations and more to achieve international peace and understanding than any other single force in the world," Charles W. Court, Minister for Industrial Development, Western Australia, told the American Mining Congress audience at the opening session of the 1969 Mining Convention, October 19-22, San Francisco. Australia, he pointed out, is a shining example. In 1971, 60% of U.S. mining investment overseas will go to Australia and other parts of Oceania, an increase of 42% over a year ago. Australia has capitalized on world needs, its own rich resources and good investment climate. Developing nations can and should do the same, but they mix emotion with nationalism, often frightening away foreign investment which could breathe life into dormant and backward areas, said Court.

Jan 12, 1969

[A session of the Institute of Metals held during the February, 1926, meeting of the Institute, was devoted to a symposium on ''gas" in copper. S. Skowronski, Perth Amboy, N. J., was chairman. On the program were papers by T. S. Fuller; W. H. Bassett and J. C. Bradley; Susan B. Leiter, and W. H. Bassett and H. A. Redworth. These papers follow the chairman's introductory discussion.] S. Skowronski, Perth Amboy, N. J.—There are today two groups of metallurgists, one group who believe in oxygen-free copper and another group who believe that oxygen is absolutely essential in copper; not that the two groups disagree, but that a certain grade of work calls for oxygen-free copper, while another grade of work does not. I can sum up the problem by reading the abstract of an article by Frederick Johnson of Great Britain in The Metal Industry of Sept. 4, 1925. Few, who have watched the trend of things during the last two decades, can have failed to notice the steady growth of opposition to the prevalent use of copper in the "tough-pitch" condition, which for many ages enjoyed an unchallenged supremacy. Broadly speaking, there are two schools of thought in the metallurgical world, one holding the view that copper containing a small proportion of oxygen is an eminently suitable material for users, the other expressing its preference, in no hesitating or uncertain manner, for copper from which oxygen has been removed by means of a deoxidizer. In the old days, before the advent of the converter and the electrolytic refining process, the copper of commerce was so impure that the presence of oxygen was imperative in order to neutralize the influence of impurities which militated against the hot-working properties of the metal. For electrical purposes, oxygen must be present, because sound bars and billets cannot be produced without it, except at the expense of electrical conductivity. For most engineering purposes, however, electro-deposited copper may be used either by itself or with the addition of alloying elements, e. g., arsenic and nickel, which experience has proved to be beneficial, such copper being freed from oxygen by the aid of a deoxidizer, e. g., phosphorus. Such material has positive advantages over "tough-pitch" copper as at present produced from refinery furnaces. It has greater toughness and malleability, and is immune from the action of reducing gases at high temperatures, the destructive action of which, in the case of "tough-pitch" copper, is well known. The reasons why there has been no wholesale replacement of "tough-pitch" copper by deoxidized copper are commercial in nature; copper can be more economically melted in large-capacity furnaces which lend themselves to the poling process and are not so suitable for control of uniformity of action of deoxidizers as the smaller electric or crucible furnaces, whilst they are also more convenient for the production of very large castings. Moreover, the equipment of most large copper manufacturing plants is designed for casting "tough-pitch " copper in open moulds, e. g., wire bars and cakes, and these could not be used for deoxidized copper, which must be cast in vertical moulds as in brass-shop practice. Further, there are still certain impure brands and

Jan 1, 1926

By R. F. Yap, N. Arbiter, C. C. Harris

A fully-instrumented driving mechanism has been constructed to study the power, aerating and solid suspension characteristics of several laboratory flotation machines. Machines operating over normal flotation speed ranges give substantially constant power numbers in liquid systems indicating that they operate close to fully baffled turbulent flow conditions. Owing to lack of geometrical scaling, power numbers for different sizes of cells of the same make are different. Even larger differences occur between cells of different manufacturers. For a given impeller, varying the tank size did not significantly affect the power consumption. Tank geometry and baffling has a slight effect on power consumption with shrouded impellers. For a given impeller speed, suspension height decreases while power increases with increasing mass of solids in suspension. While power consumption is hardly affected by particle size and clearance between the impeller and tank bottom, the suspension height significantly increases as clearance increases and as particle size decreases. Aeration was found to affect not only power but also the suspension characteristics of the machine. For closely sized particles, drastic sedimentation occurred when a critical value of the air flow number was exceeded. The critical air flow number decreased with increasing particle size. This effect was less marked with a wide particle size range. The self-aerating capacity of flotation machines increases with cell size at a given speed for the same impeller-shroud system, but decreases in the presence of frother and solids. Equations have been established for correlating all of the studied variables. Data taken from the literature were also correlated with these equations. The modern mechanical flotation machine has, over a period of 60 years, displaced other designs to become the dominant type. Once the correct chemical environmental conditions have been established, the major requirement, selective mineral-air adherence, is essentially a function of two operating variables — impeller speed and air rate. The special nature of this dependence is such that in the same apparatus, but under different operating conditions, adherence can be either prevented or destroyed. Another aspect of this observation is that flotation machines though differing in detail to a considerable extent can produce similar metallurgical results. It must be concluded that having determined the correct reagent levels, establishing the correct operating conditions are at least as important as machine design. Since about 1960, after 30 years of fairly stable circumstances, manufacturers have been developing new types of machines whose major feature is emphasis on pulp flow characteristics by virtue of new im-peller-stator designs. As far as can be ascertained, these new designs necessitate radical departures from accepted impeller speed-air rate values. Performance data are still awaited. Flotation machine development has been empirical, as is selection of operating conditions. The purpose of the work at Columbia University has been to elucidate the fundamentals of the subject so that the purely mechanical aspects of the flotation process can be understood in hydrodynamic terms.1-6 Hopefully, this might lead to intelligent selection of a particular machine and its operating conditions for a specific ore based on a minimum of testing, or even to new types of flotation machines. The present investigation is the most comprehensive to date.7,8 Earlier work, which was largely exploratory, has been repeated and extended and employes the most accurate measuring techniques available. Additionally, sufficient hydrodynamic data were obtained under flotation conditions to delineate the relevant operating ranges. Attention has been given to scaling in that several geometrically scaled tanks and impellers have been constructed and tested; it has been pointed out elsewhere that undistorted geometrical scaling rarely pertains in flotation machine design.5 This paper is divided into sections dealing with relevant combinations of the three phases: liquid, air and solid. Summaries of the literature have been given in previous publications2-4 and will not be repeated here. Recently, several reviews of mixing have appeared, which can be usefully referenced.9-11 It is of interest to note that flotation is not included

Jan 1, 1970