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By R. W. Diamond

THREE mills are now operated by the Consolidated Mining & Smelting Co. of Canada, Ltd:: (1) The Sullivan concentrator, Chapman, B. C. (near Kimberley, B. C.), (2) the St. Eugene concentrator, Moyie, B. C., and (3) the Tadanac (customs) concen-trator, Trail, B. C. Differential flotation is the only concentration method employed in all three plants. Tables are used for pilot work only. Flotation equip-ment and control are similar in the three mills, and the flow sheets at the St. Eugene and Tadanac mills, while much simpler, are modeled after that of the Sul-livan concentrator. Successful differential flotation of Sullivan ore com-menced in the spring of 1920, in the pilot concentrator at Trail. During 1920, 193,804 tons were treated by this process. This operation continued without interrup-tion and with steady growth. For the first 7 months of . 1923, which concluded the pilot plant operation, ap-proximately 1100 tons were treated daily. I believe the Sunnyside plant of the United States Smelting &. Refining Co. was the only successful and large scale operation practising differential flotation prior to 1920. in North America. The Sullivan ore, because of its high iron content, was quite a different problem from that at Sunnyside. The entire tonnage of Sullivan ore had to be separated into three sulfide concentrate products-lead concentrate, zinc concentrate and iron concentrate. The choice and arrangement of equipment, and the original flow sheet for the Sullivan concentrator were controlled by the results of the exhaustive pilot mill test. These covered a continuous period of 3 1/2 years and involved the treatment of 1,076,368 tons of Sullivan ore. Satisfactory recoveries are made from feed; 11.0 per cent lead and 7.5 per cent zinc in the form of lead concentrate containing 69 per cent lead, 4.5 per cent zinc, and zinc concentrate containing 3.0 per cent lead and 49 per cent zinc. (The pure zinc mineral in Sulli-van ore is marmatite, 'containing approximately 54.5 per cent zinc and 10 per cent iron. It is apparent, there-fore, that 49 percent concentrate is high grade for this particular ore.)

Jan 8, 1927

By R. J. Watson

In an earlier paper, Ehrenburg and Watson1 published the develop ment for a potential function by which it is possible to obtain the electric potential at points on the surface of the ground when a current I passes between two electrodes and the subsoil is composed of parallel, homogeneous layers. In view of the continued interest in the resistivity method of electrical prospecting, the author has considered it desirable to publish the results of a number of theoretical studies making use of this potential function, and also the results of a considerable number of tests with models designed to show the soundness of the mathematical theory. It is hoped that these results will prove how erroneous the various empirical rules for depth determination may be. It has always seemed puzzling to the author that one can find, in papers published comparatively recently, statements upholding empirical rules for depth determination, and attributing most of the irregularities of resistivity curves to vertical discontinuities in resistivity in the subsoil. It would indeed be fortunate for the geophysical investigator if such a simple rule held. However, numerous investigators have proved both theoretically and by the success of their field work that such a rule does not hold, even by a "rough approximation" in many cases. On the other hand, as is shown in the development to follow, if the underground conditions are favorable it is possible for such empirical rules to give a satisfactory depth determination. Authors should be more careful about making such sweeping statements about the accuracy of these empirical rules because the relative simplicity of the field work places the method in the hands of any interested experimenter, and he is likely to become completely disgusted with the method after he has made several obviously wrong interpretations by empirical rules. There are simple and rapid methods for finding out whether the ground beneath the electrodes is sufficiently similar to the conditions

Jan 1, 1934

By F. F. Aplan

For the past year, MBD has been engaged in a lively discussion on a name change for the Division. To complicate things, more than one name change has been proposed! There has been much discussion on the subject, as anyone who has attended the Annual MBD Business Meeting or read [jE] knows. The position of many of our members is well known. There is, however, one group that has not been heard from. These are the future members-the present students and those even younger who are yet to elect our profession. As one who has traversed the academic-industrial interface several times, I think I am qualified to speak for this group. Before going further I think it wise to state unequivocally that our Division should adequately represent our profession. The whole profession is just too small to chop into a plethora of pieces: "I'm not a mineral processing engineer, I'm an ore dresser-well, actually, I specialize in comminution, specifically in grinding, mostly in autogeneous grinding-primary autogeneous grinding that is-and my 'thing' is really iron ores, taconites, mind you!" Enough to confuse even those that keep the faith, and certainly we can't build a profession on such narrow pieces. Either an employer can hire a professional who knows the entire profession or he can't. As more and more companies search out opportunities in the mining and metallurgical fields and as environmental considerations bring into question even our technically well proven processes and procedures, there is a greater need than ever be- fore for a well-rounded mineral processing engineer well versed in all of the process possibilities. What is needed is one who can take an ore-or municipal trash for that matter-and produce there from a valuable product by the most appropriate means. It doesn't really matter if this is done physically, chemically or thermally.

Jan 1, 1971

By O. W. Walvoord

To those working in the mineral industry, the flowsheet is a familiar and valuable tool, seldom used, unfortunately, to its fullest advantage. As with so many other commonplace and simple items, there is little or no attempt to expand on the forms, and types of flowsheets. A flowsheet or flow diagram may be defined as an illustration showing circulation of the ore stream in a concentrating plant. It may be further described as an explanatory graphic design or picture. A flowsheet is obtained by interpreting the metallurgists' research and ore test data, usually with some adjustments to suit the economies of the project. It brings together, in compact form, information from a number of sources.

Oct 1, 1956

By Evan Evans

WITH the expiration on April 30, 1941, of the agreement between the anthracite operators and the United Mine Workers of America, a new agreement was entered into, providing for a general wage increase of 7 1/2 per cent effective May 1, to be brought to a total of 10 per cent on Oct. 1. Contract rates were increased from the rates established under the agreement of September 1923, and hourly rates were raised above the agreement of May 1936 as modified from the eight-to seven-hour day in May 1937. The new rates are to be in force for the duration of the agreement, ending April 30, 1943.

Jan 1, 1942

By M. R. Moharam

The well-known formulae of screening efficiency and circulating load calculations in closed crushing circuits were exploited to achieve graphical estimation of these parameters. Three basic charts were proposed and constructed. The first one is for the regular closed circuits where the new feed goes to the crusher. The second is for the reverse closed circuits in which the new feed reported to the screen is free of screen undersize particles. The third chart controls the reverse circuits when they are receiving new incoming feeds containing undersize material. Compound circuits were also reanalyzed and a concept of equivalent simple circuit was introduced to enable graphical manipulation of these complex circuits with the help of the aforementioned charts

Jan 1, 1982

By B. H. Bergstram, C. L. Sollenberger

When glass spheres are crushed by slow compression loading, the outer lune-shaped fragments resulting from the fracture consistently fly outward at high velocity. About 45 pct of the strain energy fed into the sphere-platen system reappears in the form of the kinetic energy possessed by these fragments. These measurements were obtained from high-speed photographs. This kinetic energy can be utilized for addtional comminution if the fragments are allowed to impact against a suitable structure. Comminution theory has advanced considerably in recent years by the study of this unit operation under laboratory conditions. Some of the parameters have been isolated, but the experimental measurements of the pertinent quantities, such as energy, particle size, etc., are still only made prior to and after the conclusion of a fracture sequence. The catastrophic fracture process itself has not been adequately studied from a comminution point of view. It has recently been suggested by Gilvarry that the fragments which result from the free crushing of a single glass sphere by slow compression contain a considerable amount of kinetic energy after fracture. This kinetic energy, if properly directed, possibly can be partially utilized to cause additional fracture. In this paper a hypothesis will be presented which suggests that this kinetic energy is necessarily present and that its dissipation is the process by which a large part of the thermal energy imparted to the crushed product is generated. Evidence supporting the existence of kinetic energy and its utilization for secondary fracture will also be presented. THEORETICAL A previous paper4 has shown that the load-deformation curve of a system composed of an elastic sphere gripped by a pair of parallel platens, can be predicted by a consideration of the theories of Hertz as summarized by Timoshenko.' The deformation A, of one half of the system is given by which states that the deformation is a function of the mutually applied load, P, the radius of the sphere, R; and the respective physical properties of Poisson's ratio, v, and Young's modulus of elasticity, Y. The shape of experimental load-deformation curves conform to this relationship. The energy input to the sphere-platen system, can be predicted from the integral of the load acting through the appropriate distance, dA. Since dA can be evaluated in terms of P from the derivative of Eq. 1, this integral can be integrated between limits of 0 and P. The test sphere, however, is loaded at not one but at two points of contact, i.e., at both ends of a diameter, and hence the total energy input, E, is twice the energy input at each end, or The energy input to the system calculated from this equation corresponds to the energy computed from the measured area under the load-deformation curve. Timoshenko, considering the impact of two perfectly elastic spheres, has shown that the inter-penetration distance A is given by - m f (D (^ * ^t w as modified for the special case where one sphere is of infinite radius, i.e., its surface is a plane; where M is the mass of the finite sphere of radius R, and V is the velocity of approach at the start of an impact and also equals the final velocity of separation for perfectly elastic bodies. Because A is also a function of the load and the elastic properties, as shown in Eq. 1, the velocity, V, can also be calculated in terms of the elastic properties and maximum load, P, or

Jan 1, 1961

US 4,192,851-Recovery of elemental sulfur and the metal values from a complex sulfide ore containing two or more of the metals zinc, lead, copper, silver, gold and/or other metals. A mixture of ore and sulfuric acid and/or spent electrolyte is flowed at optimum temperature and pressure in a quiescent zone to dissolve selected metals and sulfur and coalesce the sulfur. The coalesced sulfur and unreacted sulfides are separated by flowing the leach slurry with an upward velocity component The separated materials are discharged and further processed by conventional methods as war- ranted. H.E. Hirsch, J F. Higginson, EG. Parker, and G M Swinkels, assigned to Sherritt Gordon Mines Ltd. Mar. 11, 1980. 6 pp. (423-28) Filed. 3-14-78 (886,368). Priority. United Kingdom, 3-15-77 (10800/77).

Jan 1, 1982

Manganese nodules are essentially a surficial resource-there are four times as many nodules on the surface of the deep ocean floor as in the next 3 ft of underlying sediment. Target mine sites in the North Pacific occur in water 12,000 to 18,000 ft deep. The mining technique is comprised of four major factors: the mining device, lifting method, surface vessel, and ore transport. Certain deep-ocean mining proposals are revolutionary in character. Current research has tended to construct simple but flexible devices to work at the great depths and corrosive environments of the deep-ocean floor

Jan 4, 1975

By Frank Rieber

THE study of earthquakes long ago developed the fact that by studying the travel times of the various groups of waves from the same earthquake, as received on seismographs at varying distances, major discon-tinuities in the earth's crust could be reasonably well defined. Using this original discovery, and adapting the mathematical methods originally devised in seis-mology for determining the depth below the surface at which such discontinuities occur, other investigators were able to develop a new branch of seismology which promises to be extremely useful in extending the boun-daries of our information oil local conditions below the earth's surface. As an outstanding example of the applications of this work, we have the so-called "seismo-graph" exploration of the Gulf Coastal region, which has resulted in the discovery of a large number of salt domes, from many of which oil fields may be developed. The original seismological investigations, from which different major discontinuities in the earth's crust were deduced, as well as these later successful experiments in finding salt-dome structures, involve relatively simple problems. In each case we are dealing with surface materials in which elastic waves will be propagated with a fairly definite velocity. Under this material we have something very different, in which the elastic waves will be propagated with a much higher velocity. The transition from one medium to another is like-wise relatively abrupt. For example, in. the Gulf Coastal region the sedimentary formations have a velocity of 6000 or 7000 ft. per sec., while the velocity of elastic waves in the cap rock of a salt dome" may exceed 15,000 ft. per sec. Under such conditions, de-lineation of the formation is a relatively simple matter, and, furthermore, there is very little opportunity for ambiguous results.

Jan 9, 1928

By Lawrence K. Nordell

This paper reviews practices used In the selection and sizing of belt conveyors and stacker systems commonly used in crushing and grinding plant facilities. Historical and modern methods of sizing this equipment are presented. The new methods Include: 1) probability theory applications for establishing component reliability, 2) "Monte Carlo" simulation techniques used in evaluating alternative system designs and in establishing service factors and corresponding availability Indices of each system, 3) quantifying the system and component operating characteristics using computer assisted modeling tools simulating rigid body and elasto-mechanic behavior for starting and stopping large and/or complex belt conveyors.

Jan 1, 1982

By Bruno Nordberg

THE high cost of coal in Butte and the development of large amounts of cheap electric power from the Missouri river caused the Anaconda Copper Mining Co. in 1908 to make an investigation as to the possibility of adapting this cheap electric power for the operation of their many large hoisting plants. At this time electric power had already been adopted for practically all other power purposes around the mines, such as pumping, compressing air, etc. The map (Fig. 1) shows the location of the mines of the Butte mining district. These mines are located within a circle of approximately a 1-mile

Jan 9, 1913

By Charles F. Park

Mining in the Pacific Coastal Region has passed through three stages of development. First came the gold rush days, a period when gold and silver were the objects of intensive search. Second was the development of the high-grade base-metal deposits and of the smaller and more refractory precious metal deposits. And third was the modern period that covers the discovery and development of the rarer metals, of large low-grade deposits, and of the industrial and nonmetallic minerals. Brief discussions of the salient geologic features of the region and of a few of the better known mineral deposits are given. The regional geology is favorable for continued exploration and discovery of new deposits and districts.

Jan 1, 1968

By F. M. Jardine

I1944 the cry was for higher production more tons, more metal. New plants were built, capacity of old plants was increased and millmen all over the country were treating tonnages far above normal, sacrificing recoveries to vet that extra metal from extra tons. The list of "critical minerals," at first long, has been scratched until there remains, not a list, but only an item or two. Stocks of all metals and minerals, with possibly one or two exceptions, are now entirely adequate and numerous plants have curtailed or suspended operation.

Jan 1, 1945

By K. D. Jacob

MONTANA Phosphate Produucts Co., a subsidiary of The Consolidated Mining and Smelting Co. of Canada Ltd., operates three properties near Garrison, Mont., known as the Anderson, Graveley, and Luke mines. All three are underground operations, mining the same narrow bed at points several miles apart. The Anderson, the oldest and largest of the three, has produced about 700,000 long tons since 1929. The Graveley has produced slightly over 100,000 long tons since 1940, and the Luke, acquired in 1943, is still in an early stage of development. The great bulk of the output has been shipped to the Trail, B. C., plant of Consolidated Mining and Smelting Co. for use in the manufacture of fertilizers. The phosphate seam is the basal member of the Permian Phosphoria formation. In all three mines it has a uniform thickness of 3 to 4 ft. of oulitic phosphate, with a few shaly partings. The overlying part of the formation comprises about 50 ft. of chert and the immediate footwall consists of a few feet of shale and sandstone. underlain by the Quadrant quartzite.

Jan 1, 1944

By Yang Tsang Woo

The method of making coke that has been adopted at the Kaiping and other collieries in northern China resembles, to some extent, the familiar bee-hive oven process of the United States, except that a kiln with permanent sides is used instead of a closed oven, and the products of combustion are drawn off at the bottom. In building coke-kilns in China, two circular holes, 8 ft. 6 in. in diameter at the bottom and 13 ft. in diameter at the top, are excavated in the ground, and connected at the bottom by a flue, as shown in Figs. 1 and 2. The sides and bottom of the kiln are lined with fire-bricks, and covered with a lager of fireclay, and a rectangular opening, 6 in. by 8 in., connects the bottom of each kiln with the main flue. Around the edge of the hole, and overlapping the lining, is a wall of fire-brick extending 2 ft. 6 in. above the level of the ground. An open space 5 ft. wide is left in this wall, through which the coal is carried into the kiln and the resultant coke removed. This space, of course, is bricked up during the time that the coking-operation is being carried on. The wall is pierced with nine flue-openings uniformly placed around the circumference, each interverliilg space in the wall being strengthened with a brick buttress, as is shown in Figs. 2 and 4. The floor of the kiln, as well as the main flue, is lined with fire-brick. Before charging the coal, it is first placed in shallow bamboo sieves, 2 ft. in diameter, and immersed in a trough 10 ft. long, and 3 ft. wide, fed with pit-water, in which it is washed by hand. Fig. 3 shows the manner in which the washing is done. From 25 tons of good "dust" coal, 22.5 tons of washed coal are obtained. When ready to charge the coal into the kiln, a temporary cone-shaped flue of fire-wood and lump coal is first built to a

Jan 1, 1906

By G. W. Preckshot, J. W. Gorman

MOLTEN metals offer an excellent medium for the study of molecular diffusion and interphase transfer. In the absence of intermetallic compound formation, solutions of molten metals are solutions of elements. Therefore, complicating factors such as molecular structure, dissociation, association, polarization, and so on, are generally absent. Further, metals remain in the liquid state over a wide range of temperature. Thus, the effect of temperature on transport processes can be studied in more detail. Although some data are available for the diffusion of metals in the molten state at high temperatures,"""".'!' the most useful and accurate data are those for the diffusion of various elements in mercury at room temperature. The effective radius of diffusion for the various elements in mercury may be calculated from the Stokes-Einstein relation.'-These calculated radii are compared with the atomic and ionic radii calculated from X-ray data on crystals." The effective radii of diffusion of the alkali and alkali-earth metals correspond to those of the neutral atom; those of cadmium, silver, lead, zinc, thallium, bismuth, and tin correspond to ionic radii; and those of copper and gold indicate larger radii due to association with mercury or more likely, faulty diffusion data. Independent evidence"' supports the notion that alkali metals are uncharged in amalgams. The concept of metals moving free of their conductance electrons in the liquid state has been discussed by Eyring, et al,'" in connection with studies on the viscosity of pure molten metals. Considering the approximate nature of the tabulated atomic and ionic radii and the variance in the diffusion measurements, the application of the Stokes-Einstein equation to the diffusion of metals in mercury gives gratifying results. It is noted that a number of these metals have article radii eaual to or less than those of the solvent mercury.".'*,"' Soba1,'" sing the inaccurate Roberts-Austin20 data, indicated that the effective radius of diffusion might well be a function of temperature. Additionally in studies of mass transfer between phases, many conflicting opinions have been expressed concerning the assumption of equilibrium at the interface." ,","," The results of the present work on the diffusion of solid copper in molten lead throws light on the tempera- ture variation of the diffusion radius as well as the extent of the interfacial resistance. The theoretical background and experimental procedure are presented here in detail. Results on other systems will be presented in subsequent papers. Nomenclature The following nomenclature is used in the paper: A—cross-sectional area of diffusion column, sq cm C, C,—concentration of solution and saturated solution respectively, g per cc D,D'—-diffusivity, sq cm per sec e—Naperian base h—ratio, k/D k—mass-transfer coefficient, cm per sec L—diffusion column length, cm n—series index q—flux, g per sq cm-sec r—radius, cm or A R—-gas constant t—time, sec T—temperature, K V—volume, cc w—weight of copper-lead alloy on copper cylinder WT—-total copper transferred to lead diffusion, column, g Z—distance from top of diffusion column, cm 2'—distance from copper-lead interface, cm (2' = L-2) u,,—roots of diffusion equation Mathematical Apparatus The model shown in Fig. 1 applies to the diffusion of solid copper into molten lead. Here Fick's first law may be written where all terms are defined in the nomenclature. It is assumed that the volume of the lead column is constant. This is justified since experimental densities compared favorably with calculated densities based on perfect interstitial mixing. Thus there is no counter diffusion of lead. It is clear that 2 in Equation [I] should be measured relative to the interface which moves relative to the diffusion cell but not to the liquid phase. Hence, the frame of reference is the plane of the copper-lead interface. The diffusivity calculated at constant volume, D", is that defined by Hartly and Crank" and is designated herein as D. No Interfacial Resistance—The two situations of the presence and absence of interfacial resistance will be treated. The simplest is the latter which re-

Jan 1, 1959

E. E. THUM,* Salt Lake City, Utah (written discussion?).-While the present paper is confined exclusively to the microstructure of fusion welds, it may be of interest to draw attention to certain appearances existing in resistance welds such as spot or butt-welded joints produced by the Thomson process. For instance, a butt weld between two pieces of carbon tool steel (carbon about 0.90 per cent.) will show concentric ellipsoids of the various materials from pearlite to martensite. The surfaces of demarcation are quite well defined, the center of the ellipsoid being at the intersection of the axis of the piece and the plane of the weld. Often these unannealed welds show a troostitic center; evidently this core was not quenched as rapidly as the surrounding shell. Such specimens are beautiful samples for instruction purposes. An annealed butt weld of this kind will show a very well defined central ellipsoid of decarburized, materials. It is interesting to consider the reason why this change takes place. It must be understood that the heat is on the metal for a very short time, possibly 30 sec. It is therefore evident that the decarburization, or migration, of the carbon takes place with extreme rapidity. Since no blowholes are evident in a well-made butt weld, the deoxidizing air and the products of combustion must migrate with the highest speed; second, the carbon might migrate back into the stock; or, last, a large proportion of the pearlite may be extruded with the hot metal, which forms a fin at the plane of weld. Examining these possibilities in detail, it is not probable that such deep-seated decarburization, extending with maximum effect to the very center of a 2-in. round bar, is done by reaction with the oxygen of the air. This would postulate entrance of oxygen and egress of carbon oxides in large quantity without leaving behind traces in the form of oxides or

Jan 5, 1919

By J. G. Baragwanath

CUBA'S lateritic iron ores, occurring on the northern coast of that island, though known to the Spaniards. did not receive any general attention until the close of the Spanish-American War. Preliminary studies of these deposits at that time indicated that the limonite contained small percentages of nickel and chrome, and it ryas subsequently discovered that although the average nickel content was only approximately 0.6 per certain limited areas of ore were suffiniently high in nickel to be considered commercial provided a suitable process fur its recovery could be developed. Early in 1937, Pardners Mines Corp. began a series of investigations which led to the development of such a process. Coincidentally, this company acquired option' on certain properties in the Levisa Bay and Moa Bay regions and conducted a systematic campaign of exploration by test pits and hand-auger holes in the course of which an aggregate of 90.000.000 tons of ore was developed in eight deposits.

Jan 1, 1945

By A. H. Tousley

Current problems in the cement industry are discussed and suggestions for solving them by modernization are made. Cement facility modernization is discussed in considerable detail with examples illustrating before and after conditions. Itemized are the improvements realized in better working conditions, better efficiency, higher production, lower costs, and better community relations. These improvements are related to the overall profitability of the particular plant or facility.

Jan 1, 1972