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By T. T. Chen, P. Pint

Based on the mineralogy, phase characteristics and compositions of the smelter feed, the smelter products and the smelter wastes, the sources and distributions of mercury and arsenic in the Afton copper smelter, Kamloops, British Columbia have been determined. Of the total mercury In the feed, approximately 33% is in solid solution in tennantite, 51% is in native copper and 16% occurs as mercurian silver. Arsenic in the feed occurs mainly as tennantite. Under current smelting conditions, 99.6% of the total mercury In the feeds enters the off-gas cleaning system. From this off-gas, about 1% of the total mercury, occurring as dust, is recirculated to the flotation concentrate; 4.6% of the total mercury is contained in SO2 scrubber sludge which is discharged to tailings. Approximately 78% of the total arsenic in the smelter reports in the copper products; 20% is incorporated in the dust and slag which are subsequently recirculated to the mill. Only 1.8% is rejected as scrubber sludge, and less than 0.2% 1s released to the mercury scrubber.

Jan 1, 1984

SEC. 1. The membership of the Institute shall comprise seven classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members; 7. Junior Foreign Affiliates. All shall be equally entitled to the privileges of membership, excepting that no member of any class whose residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the. class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members. SEC. 3. Honorary Members: Each candidate for Honorary Membership must be recommended by at least ten Members and must be elected by ballot at a meeting of the Board of Directors by the unanimous vote of the Directors present; provided, however, that the number of Honorary Members shall at no time exceed twenty. Such election shall automatically act as a transfer of such member from any other class of membership to which he may belong. SEC. 4. Senior Members: The Directors may, at the special request of any Member or Associate who has reached the age of seventy years and who has paid dues for thirty years, transfer such Member or Associate to the class of Senior Member; and in special cases may waive either the requirement as to age or as to the number of years for which dues have been paid. SEC. 5. Junior Members: A person to be eligible for election to the class of Junior Member must be qualified -through education or experience to hold a subordinate position in engineering, mining, metallurgical, geological or chemical work. He shall be not more than 33 years of age at the time of election. .SEC. 8. Associates: A person eligible for election or transfer into the class of Associate shall be one, who, in the opinion of the Committee on Admissions and the Board of Directors, is suitable for such election or transfer by reason of his interest in or connection with mining, geology, metallurgy, or chemistry. SEC. 7. Rocky Mountain Members: Membership in a special class of life memberships without annual or other dues and without right to receive the printed literature distributed to other members or the right and privilege of wearing the official badge of technical members, is given to all members of the Rocky Mountain Club at the time of consolidation. These special Rocky Mountain memberships shall be claimable by any member of the Rocky Mountain Club, not already a member of the Institute, availing himself of the privilege within ninety days after mailing of notice to him, by the Secretary of the Institute. SEC. 8. Junior Foreign Affiliate: Upon appropriate action by the Board of Directors and with its approval, members in good standing of any technical society having its headquarters outside of the United States of America, Canada, or Mexico,

Jan 1, 1940

By C. D. Gilpin, Franklin Moeller

The application of electric power for driving mine hoists handling heavy loads at high speeds has recently been extended by the installation of what is probably the largest electrically driven hoist in this country at the Granite Mountain shaft of the North Butte Mining Co., Butte, Mont. While the weight of rock which is hoisted by this machine is not the largest now being handled by electric mine hoists, the speed of hoisting is so, and the combination of the high speed with the heavy load has resulted in a machine of considerable interest to all those actively engaged in mining. Aside from mere considcration of size, this installation deserves attention because of the careful attention given, not only to the question of economy of operation, but to the details of construction and installation of the entire equipment. The conditions to be met in this installation were as follows: Weight of rock to be raised per trip, 7 gross tons........... 15,680 1b. Weight of skip.......................................... 8,000 1b. Weight of cage.......................................... 1,800 1b. Maximum depth of hoisting.............................. 4,000 ft. Diameter of rope.......................................... 15/8 Total weight suspended on one rope from drum............. 42,000 1b. Normal hoisting speed.................................... 2,700 ft. per minute. Maximum hoisting speed.................................. 3,000 ft. per minute. Desired capacity-200 tons per hour from 4,000 ft. depth. The ore is mined in several levels and hoisting is carried on from the 800-ft. level down to the 2,700-ft., which is at present the maximum depth from which the ore is raised regularly. Development is proceeding and a depth of 2,900 ft. has already been reached. The rock is handled underground in cars holding % ton, and about 10 cars are the usual load for a skip. All of the ore is dumped into underground bins, which are of diffcrent capacities varying up to 250 tons. From the bins the ore is fed into the skips without passing into measuring pockets. At the surface the

Jan 1, 1916

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made. his gift ?for the erection of a suitable home? for the engineering societies,

Jan 1, 1942

By E. M. Wise

The practice of adding moderate quantities of nickel to a variety of bronzes has been employed by foundrymen for many years with several objects in view. In some instances it was desired to harden the alloy; in others it was to increase the fluidity or to improve the solidity of the castings, or to refine their grain. These important matters have been considered in detail by Pilling and Kihlgrenl and by numerous other workers cited by them, and with the exception of the first will not be considered in the present communication. The possibility of reducing the cost of bronze by replacing a portion of the tin with nickel received attention some years ago by Burgess and Woodward12 and, as will be shown later, offers attractive savings in cost under present conditions. The age-hardening characteristics of the nickel bronzes of appropriate compositions have been known for some time and were mentioned by Price, Grant and Phillips3 and discussed by Wise4 in connection with their paper. These matters are further considered in recent patents15 and are becoming of commercial importance in the production of high-strength castings. The equilibrium relations existing in the high-copper region of the copper-nickel-tin system have been carefully studied by Eash and Upthegrove,6 and in somewhat less detail by Veszelka.7 The observa-

Jan 1, 1934

By Nathaniel Herz

(San Francisco Meeting, September, 1915) THE use of zinc dust for precipitating the precious metals from cyanide solutions is well established now in many places, and has many advantages over the shavings method of precipitation. Although much work has been clone on methods of testing zinc dust, as yet no absolutely positive test has been devised to determine the value of the material. Certain facts are known, but often it happens that results on a working scale are not as expected from the laboratory tests. The purpose of this paper is to record some observations made while testing. a large variety of zinc-dust samples in the laboratory. W. J. Sharwood1 has described standard analytical methods, which have been followed, with the changes noted. The regular determinations include zinc oxide, by solution in ammonia and ammonium chloride, lead, and precipitating efficiency. In some cases cadmium was determined by a method similar to that described by J. E. Clennell.2 I will discuss the precipitating-efficiency test in detail. The procedure is as follows: "A solution of potassium silver cyanide is prepared by dissolving 10 grams of silver cyanide (AgCN) and 5 grams of `99 0' potassium cyanide in a little water and diluting up to 1000 cc. It is then adjusted by addition of a little more KCN or AgCN until the solution indicates from 0.12% to 0.15% free KCN by titration with standard silver nitrate. The titration is best made by using a 10-cc. or 20-cc. sample, adding 1 cc. of 2 % potassium iodide, and a slight excess of ammonia, as the end point is then sharper. Or 15 grains of pure crystallized KAg(CN)2 may he dissolved in a liter of water and 1.5 grams KCN added. "Weigh out 0.5 grain zinc dust into a 300-cc. beaker. Add a few cubic centimeters of water and stir until, zinc is well mixed, then pour in 250 cc. of the prepared solution, stirring vigorously. See that all lumps are broken up, and continue stirring for fully five minutes. Stir occasionally (at least every 10 minutes) until the end of two hours from the addition of the solution. Then filter upon an 11-cm. filter, wash precipitate thoroughly, sprinkle with test lead, wrap it carefully in the paper, plaice in a scorifier with about 20 grams test lead, burn paper cautiously in muffle, scorify five minutes, cupel at low temperature and weigh silver. Milligrams silver obtained from 0.5 gram zinc X 0.0606 = percentage precipitating efficiency."'

Jan 8, 1915

By A. H. Larson, R. J. McClincy

ALTHOUGH arsenic has a very high vapor pressure and vacuum distillation appears to be a likely method for its removal from lead, the published literature contains virtually no information concerning the vacuum removal of arsenic from lead. Caldwell, Spendlove, and St. Claire1 mention arsenic in their investigation of the removal of volatile metals from lead by vacuum distillation. They do not, however, give any data for arsenic removal or refer to any actual experimental work involving arsenic dissolved in lead. Moriyama, Kozuka, and Miura2 have determined the activity of arsenic in dilute As-Pb alloys in the temperature range from 450" to 600°C using a closed galvanic cell. They found that the activities of both arsenic and lead showed a positive deviation from ideality at 600°C. In view of the lack of experimental data regarding the vaporization of arsenic from As-Pb alloys, a limited vapor pressure study was made on liquid alloys containing from 0.5 to 3.3 wt pct As in lead at 703°C. The pressure of As4(v) above the alloys studied was determined from weight-loss data collected by means of the inert-gas saturation method. The experimental apparatus and procedure used were similar to that discussed by Alcock and Hooper9 with modifications as described by the authors., The technique involved was one of passing a known volume of inert gas over the alloy to be studied in a known amount of time and determining the loss in weight of the sample. Because of the low vapor pressure of lead at 703"C, the observed weight loss could be attributed solely to the vaporization of arsenic as the tetratomic molecule AS43 Measurements of the apparent vapor pressure were repeated at different inert-gas flow rates until from three to five values were obtained which were independent of inert-gas flow rate. This value of the apparent vapor pressure was taken to be the equilibrium vapor pressure of the alloy under consideration. The vapor pressures measured in this investigation have been converted to the activities of arsenic in As-Pb alloys, Table I, by use of the data compiled by Elliott and Gleiser5 for the vapor pressure of pure arsenic. The standard state for arsenic was chosen as the pure, hypothetical, supercooled liquid. The activity of arsenic was calculated from the fourth root of the ratio PAs,/PAS,. The low magnitude of the vapor pressures given in Table I explains the difficulty en- countered by earlier workers in successfully vacuum distilling arsenic from very dilute As-Pb alloys. The data shown in Fig. 1 indicate that the As-Pb system behaves ideally. The apparent outlier represented by the alloy containing 1.43 mol pct As is a result of the fact that the pressure of As, above the alloy was barely detectable by the experimental procedure used in this investigation. Because of this, the apparent vapor pressure determined for this alloy could be in considerable error. Moriyama, Kozuka, and ~iura' have reported that arsenic shows a positive deviation from ideality in dilute solution in lead. However, details of their results have not been made available. This research was made possible by a grant from the National Science Foundation (GK-196) for which the authors are very appreciative.

Jan 1, 1970

By Chikaosa Tanimoto

INTRODUCTION The committee on Rock Mechanics, Japanese Society for Civil Engineers, has been discussing 'soft rock engineering in Japan' and presented several papers concerning dam, tunnel, bridge and slope constructions to International Symposium on Weak Rock, Tokyo 1981. This is the summarized paper based on References of Okamoto et a1 (1981), Iida et a1 (1981), Working Group on Tunneling-JSCE (1981), Working Group on Bridge Foundations-JSCE (1951) and Kikuchi et a1 (1981), which can convey general view on engineering experiences with weak rocks in Japan. From the point of view to the origin and/or distinctive physical properties, weak rocks in Japan may be classified into (1) sedimentary, (2) weathered, (3) low welded-pyroclastic and (4) fractured ones. Their typical characteristics are summarized in the following section. Concerning dam foundations on soft rock, several hundreds have already been constructed and, at present, nearly one hundred are under construction or at planning stage. These dams, almost without exception, have some problems such as site selection, material selection for fill-type and concrete dams, design of dam and its foundation, and construction procedures, requiring special ingeneous and cautious measures to cope with the local geotechnical difficult situations. In tunneling, for the decade of 1970s, the number of tunnels in soft rock either completed or under construction was at least 160, including Seikan Tunnel of 53.9 km long, Nakayama Tunnel of 14.8 km long and so on. Most of these tunnels are distributed in the northern half of Mainland, consisting of a basement of Paleozoic strata and Plutonic rocks, overlayed by Neogene Tertiary formations which include large

Jan 1, 1982

By R. McNeill, D. E. Weiss, E. A. Swinton

In a continuous countercurrent exchange process, an alteration in any one of the operating conditions has a complex effect on the others, which can only be predicted by employing the transfer unit or the theoretical stage theory on a basis of trial and error. A simple method is described for illustrating diagrammatically the behavior of a counter-current system, the equations being simplified by means of a concept the maximum hypothetical exchange performance. An example based on a typical metallurgical system is given, in which a divalent metal is recovered from a dilute solution, the resin being regenerated continuously by a monovalent ion. Useful conclusions are drawn from a study of the theory. Practical methods for performing continuous ion exchange are discussed, and the development of equipment based on modified ore dressing jigs is described. A swinging sieve jig contactor is evaluated experimentally. DURING the last decade, the new synthetic ion exchange resins have been applied extensively in industries outside the field of water treatment, but there is no record of a continuous counter-current process operating on an industrial scale. Attempts have been made to devise a satisfactory process but many problems remain to be solved. The basic principles of continuous processes will be outlined, as well as the major problems in their operation and the progress made in the CSIRO laboratories toward the development of satisfactory industrial techniques. In the metallurgical field ion exchange resins can be used for various applications such as the recovery and concentration of valuable metals from mine waters,' the regeneration of pickling and plating liquors," the prevention of pollution by waste effluents and the recovery of the constituents from them," and the purification of valuable metals such as the rare earths by chromatographic fractionation on columns of ion exchange resins.7,8 . Turther applications undoubtedly will be found in the field of hydrometallurgy where the use of ion exchange resins would enable direct extraction of the desired metal ion from the filtered leach liquor or the leach pulp. For example, an ion exchange process has been described recently for the extraction of gold from a cyanide leach pulp." A continuous process would have advantages in many applications over the usual process employing a fixed bed and intermittent cycle. In a recovery process, it would yield a product stream of steady purity and concentration, it would waste less water in rinsing, and if the contacting apparatus were efficient less resin would be used, since each portion of the resin would be cycled as soon as it was loaded instead of lying idle until the whole bed was ready for regeneration. A very major advantage is that it would be simpler to control automatically. It is probable that continuous operation will be the key for really large scale applications of ion exchange. The flow sheet of a continuous ion exchange recovery-concentration process is illustrated diagrammatically in Fig. 1. Dilute liquor containing the valuable ion flows through the stripping section countercurrently to a moving bed of resin and leaves after a final contact with freshly regenerated resin. The resin leaves the unit almost in equilibrium with the incoming liquor and then flows to the regenerating unit where it is treated by a slow countercurrent flow of concentrated regenerant solution. The adsorbed ion is displaced from the resin and appears in the concentrated product stream. The resin then must pass through a rinse unit or section where regenerant entrained by the resin is washed back into the regeneration section by water. The regenerated and washed resin is then recycled back to the stripping section. I. Theoretical Operating Behavior of Continuous Ion Exchange Stripping System The simple theory of continuous ion exchange is analogous to that of solvent extraction and other diffusional transfer operations and is governed by the equilibrium relationship, the mass balance, the rates of mass transfer, and the contacting efficiency of the unit. Equilibrium Relationship—The relative affinity of two ions A and B, for a particular resin immersed in their solution, can be expressed by plotting compositions of the solution against compositions which exist in resin in equilibrium with those solutions, i.e. C/Co vs q/a where C, is the total normality of the solution, C is the normality of ion A in the solution, a is the total exchange capacity of the resin in gram equivalents

Jan 1, 1956

Discussion of a paper of S. S. Rummy and W. F. SCHWEDES, presented at the Pittsburgh meeting, October, 1914, and printed in Bulletin No. 94, October, 1914, pp. 2613 to 2635. K. A. PAULY, Schenectady, N. Y.-I have seen this installation and I wish all those interested in the question of electricity as a mine pumping agent could see it. It is not only a model for mine installation, but might well serve as a model for any electrically driven pumping plant. I think I am correct in saying that the pumps are the largest electrically operated centrifugal pumps in mine service in America. I talked with Mr. Rumsey in Duluth just before coming here, and he told me that the actual tests of the equipment as installed checked very closely with the shop tests; that the water delivered by the pumps was slightly in excess of the guarantee, something like 3 or 4 per cent., and that no troubles except of a very minor nature had been experienced with the installation from the start. One point which has been brought out by Mr. Rumsey, and by others who have looked into this question, is the marked saving which' can be made by the application of electricity to pumps, especially to the main sump pumps. The pumps are always located a long distance from the boiler plant and the losses in the steam mains are large. While many of the steam pumps are of a very high grade, yet the tests seemed to indicate that the steam consumption is extremely large. The reduction in operating cost of one small installation which I. have in mind pumping against a head of approximately 2,000 ft.-which by the way was a reciprocating pump-reduced the pumping cost to the neighborhood of one-fifth of the previous steam cost. . The high steam cost was probably due to leakage in the engine and the loss in transmission in the mine, the pumps being located almost half a, mile from the boiler plant.

Jan 4, 1915

By Fred Hale

OWING to the large area included in the Yellow Pine mining district, and the-varied nature of its mineral deposits, a detailed geological description of the district could be covered only in an extensive monograph. This paper is intended as a description of the most prominent geologic features only with special reference to those of economic importance. The first mention of the district was in 1903 by J. E. Spurr,1 who briefly describes the structural geology of the Spring Mountain range. In 1906, H. F. Bain2 briefly described the Potosi mine. James J. Hill,3 of the United States Geological Survey, visited the district for a brief period in 1912, the result of which is an excellent reconnaissance report, covering the district in some detail but necessarily with brevity. Since that time, articles covering special features of the district have appeared in the technical press, including some by the writer, and a notable description of the Boss mine, by Adolph Knopf,4 appeared in 1915. Development of the district during the past few years has progressed so rapidly and with so many notable discoveries, particularly with reference to the rare metals, that a further description at this time may prove of interest. The writer's acquaintance with the district is based on 7 years' continuous residence in the vicinity, beginning with the spring of 1910.

Jan 2, 1918

By Frank C. Smith

THE following article covers the history of a metallurgical campaign, commenced in March, 1905, at the mines of the Socorro Gold Co., in the so-called desert region of Yuma county, Arizona. The results obtained were simply a function of necessity, as will be seen from the description of the local economic conditions and the character of the ores treated. The mines and mill of the Socorro Gold Co. are located near the small village of Harrisburg, about 60 miles from Congress Junction, Arizona, which, at the time this work was undertaken, was the nearest railroad station, and from which all supplies were brought by wagon through the desert, at a cost varying from $10 to $15 per ton in addition to the railroad freights. Wood, the only available fuel, cost $7 per cord. Water for all purposes was pumped to the plant from a well in the valley about 4 miles away. Under the Arizona law, a working-shift is 8 hr. Wages were $6 per day for foremen and mill-men, $4 per day for blacksmiths and engineers, $3.50 per day for miners, and $3 per day for shovelers and trammers. The ore consisted of quartz, in which, above the 250-ft. level, the iron-minerals were largely oxidized and some free gold was visible; below that level few traces of oxidation occurred, and pyrite constituted the principal mineralizer in the quartz, together with occasional pockets of galena and a few eccentric specks of covellite. The 20-stamp mill was equipped with plates for amalgamation, and three Standard tables for concentration. The tails from the tables were elevated by a centrifugal pump to a launder, by which they were conveyed to a 60-ton cyanide-mill for further treatment. The cyanide-mill was erected at so great a distance from the stamp-mill that a separate crew of workers and a separate power-plant were necessary. No arrangement had been made for the treatment of the concen-

Jan 1, 1907

CENTRAL EMERGENCY COMMITTEE Chairman, MRS. H. N. SPICER As no further requisition will be Made for knitted garments, for the boys of the 27th Engineers, all completed garments and wool have been collected and returned to Mr. W. R. Ingalls, and the activities of the

Jan 12, 1918

JOHN H. NELSON, Worcester, Mass.-At our plant we have done considerable work on notch-bar testing and are farther at sea now than when we started. So far, we have been unable to get the notch-bar test to be consistent with any other known test. Lately, I have been investi-gating the effect of the position of the notch-bar specimen in a, bar. To do this I took a 3, ½ in. square bar and quartered it, then heat treated the four quarters. Each of these pieces was again quartered and a specimen machined and notched. "In this way we would have notch-bar tests from the exterior to the interior of the bar. These were made of such lengths that it was possible to make four impact tests on each speci-men. Extreme care was taken in marking the position of these test speci-mens in the original bar. The notches were then cut with relation to position of the specimen in the original bar. The second notch was cut 90° from the first, and so on around the specimen. In this way, we have found that, with a 3 ½ in. bar of 0.4 or 0.5. per cent. carbon steel when properly heat treated, we could get impact values ranging from 15 to 100 ft.-lb. Just why this is the case we are unable to state; but it does appear to be a fact that along the outside of the original bar the notch-bar test seems to be low and increases toward the center, but it is not always consistent. For instance, we may have, on a single specimen; one notch-bar test giving us 15 ft.-lb. and another 100 ft.-lb. We have not found such inconsistencies in alloy steels. Alloy steel is consistently good or consistently bad. If it. is good, you cannot readily destroy the impact value, no matter what you do; if it is bad-that is, if it is a poor notch-bar steel-and you have sufficient latitude in your draw, you may correct it. In other words, if the hardness you are working to will allow you to draw to about 1050° F.(561° C.) or over and then quench this steel from the draw heat, you. can raise the im-pact value of the steel from about 4 or 10 ft.-lb. up to-40-or 50 ft.-lb: Just what occurs I do not know. There is evidently a critical-point in steels that have poor impact value, in the neighborhood of 1000 F. to 1050° F. (536° to 561° C.).

Jan 12, 1919

By R. B. Ladoo, C. A. Stokes, R. N. Secord, A. L. Hall

INDUSTRIAL mineral history shows that the entrance of new, nonmetallic minerals into commercial production can be expected to occur from time to time. Latest entrant into the field is wollastonite. Except for one short-lived period in Kern County, Calif., starting in 1933, wollastonite has never before been produced on a commercial scale. But the signs are up for its entrance as an economic factor in the mineral market. Small scale experimental production from a deposit near Willsboro, N. Y., started about 1943. A pilot plant was built in 1949-50 and irregular, small scale, production has continued. In early 1951 Godfrey L. Cabot, Inc. of Boston, world's largest producer of carbon black, took an operational lease on the property to study the deposits and make market surveys. This became Cabot's first venture in the mineral field, when they took over operations and began design of a new mill, expected in production in 1953. Properties The properties and major uses of wollastonite are comparable to New York fibrous talc. It has about the same specific gravity and index of refraction as talc, but is somewhat whiter and softer. The two most important fields of use, paint and ceramics, are the same as for talc. Ground wollastonite has a fiber length as much as 13 to 15 times the diameter. This particular property makes it applicable in the paint field and others. In addition, the length-diameter ratio may be controlled to rather narrow limits by choice of grinding method. Another important commercial property is brightness or whiteness. Wollastonite reads from 92 to 96 pct of MgO on the G.E. brightness meter for a 99 pct -325 mesh grind. Purity and uniformity of product are important. Chemically, the wollastonite now being mined analyzes SiO2 51.76, CaO 47.56, FeO 0.46, MnO 0.04, and H2O 0.09 pct. Theoretically pure wollastonite analyzes SiO2 51.75 and CaO 48.25 pct. This analysis indicates over 98 pct calcium silicate, with only small amounts of contaminating ingredients. That these ingredients are not detrimental to color or brightness is shown by the high brightness value of the fine ground material. [ ] By-product calcium silicate from electric furnace production of phosphoric acid has little physical re-semblance. to this wollastonite, being an off color white, and lacking in fibrous crystalline character. Minerology Wollastonite is a calcium metasilicate, CaSiO3, a white, medium hard, fibrous mineral. In this deposit wollastonite occurs as well crystallized aggregates of bladed crystals intergrown with garnet, and with a few percent of green diopside. The beneficiated product is about 75 pct wollastonite, 15 pct garnet, and 10 pct waste, largely middling. Wollastonite-garnet ore occurs in at least two beds. The main bed, varying in true thickness from 30 to 70 ft, dips into the hill at an average 30° and is enclosed in gneisses. Diamond drilling has proven the orebody to an average depth of 200 ft along 2000 ft of outcrop with adequate tonnage for many years of quarry operation. The wollastonite-garnet ratio varies locally, but average composition is uniform over long distances. A friable ore, it is easy to drill, shoot, and crush. Beneficiation Unlike talc this ore has to be beneficiated. Successful treatment depends upon the fact that it contains virtually nothing but wollastonite, garnet and a minor percentage of diopside. A very pure wollastonite product can be made by high intensity magnetic and/or gravity separation methods.

Jan 1, 1952

By Leonard B. Lipson

Boyer, Morgan and Muskat,' with improvements by Morgan, McDowell, and Doty,l and Laird and Putnam,' have described a scheme for the determination of fluid saturatic in porous media by measuring the x-ray linear absorbing power of particular fluids in the media. This method is one of several which depend on the linear absorbing power of the fluids in the porous medium. Other examples of linear absorption methods involve measurement of dielectric constant, gamma ray absorption, and ultrasonic attenuation. It is the purpose of this note to demonstrate by theortical considerations that the absorption versus saturation curve for a linear absorption method is not necessarily a single valued function of the saturation. Such non-unique behavior must be considered and evaluated before suitable saturation determinations can be made by a linear absorption method. To illustrate the discussion, examples will be given only for the simplest cases of combinations of two different dielectrics. The dielectric constant method was chosen for illustration because it was thought to demonstrate most graphically the point in question. According to Argue and Maass,4 the resultant dielectric constant of a combination of two different dielectrics depends on the orientation of the dielectrics in the electric field of the test condenser used to measure the dielectric constant. One ease involves alternate slabs of dielectrics E1 and E2 perpendicular to the electric field of the test condenser, as shown in Fig. 1A. For this case: l/'E, = A/E, + B/E,.......(1) where E,,, is the dielectric constant of the combination, A is the ratio of the path length through dielectric E, to the distance between the plates of the condenser (assuming the dielectrics have the same cross sectional area as the condenser), and B is the ratio of the path length through dielectric E2 to the distance between the plates of the condenser. It will be noted that the constants A and B are numerically equal to the fractional "saturation" of the region between the test plates of the condenser by the two dielectrics E1 and E2, respectively. Another case involves alternate columns of the two dielectrics parallel to the electric field and forming a continuous path between the condenser plates, as shown in Fig. 1B. For this case: E., = AE1 + BE2.........(2) where E., is the dielectric constant of the combination, A is the ratio of the cross sectional area of dielectric E, to the cross sectional area of the condenser plates (assuming the lengths of the dielectrics equal the distance between the condenser plates) and B is the ratio of the cross sectional area of dielectric E2 to the cross sectional area of the condenser plates. As before the constants A and B are the effective "saturation" of the condenser by the two dielectrics. Still another case is described by Lichtenecker5 where dielectric E2 is shown in the form of small particles distributed at random in dielectric E1. This is shown in Fig. 1C. For this case: log Em = A log E1 + B log E2.....(3) where Em is the dielectric constant of the combination. A is the ratio of the volume of dielectric E1 to the volume of the condenser, i.e., the effective "saturation" of the condenser by dielectric E,. B is the ratio of the volume of dielectric E2 to the volume of the condenser, i.e., "saturation" of dielectric El. Equations (l), (2) and (3) are plotted in Fig. 2 for E1 = 2.5 (oil) and E2 = 80 (water). Equations (1) and (2) may he thought of as representing the limiting cases of the configuration of two fluids which might be expected to exist in a porous medium. Equation (3),

Jan 1, 1951

By Leonard B. Lipson

Boyer, Morgan and Muskat,' with improvements by Morgan, McDowell, and Doty,l and Laird and Putnam,' have described a scheme for the determination of fluid saturatic in porous media by measuring the x-ray linear absorbing power of particular fluids in the media. This method is one of several which depend on the linear absorbing power of the fluids in the porous medium. Other examples of linear absorption methods involve measurement of dielectric constant, gamma ray absorption, and ultrasonic attenuation. It is the purpose of this note to demonstrate by theortical considerations that the absorption versus saturation curve for a linear absorption method is not necessarily a single valued function of the saturation. Such non-unique behavior must be considered and evaluated before suitable saturation determinations can be made by a linear absorption method. To illustrate the discussion, examples will be given only for the simplest cases of combinations of two different dielectrics. The dielectric constant method was chosen for illustration because it was thought to demonstrate most graphically the point in question. According to Argue and Maass,4 the resultant dielectric constant of a combination of two different dielectrics depends on the orientation of the dielectrics in the electric field of the test condenser used to measure the dielectric constant. One ease involves alternate slabs of dielectrics E1 and E2 perpendicular to the electric field of the test condenser, as shown in Fig. 1A. For this case: l/'E, = A/E, + B/E,.......(1) where E,,, is the dielectric constant of the combination, A is the ratio of the path length through dielectric E, to the distance between the plates of the condenser (assuming the dielectrics have the same cross sectional area as the condenser), and B is the ratio of the path length through dielectric E2 to the distance between the plates of the condenser. It will be noted that the constants A and B are numerically equal to the fractional "saturation" of the region between the test plates of the condenser by the two dielectrics E1 and E2, respectively. Another case involves alternate columns of the two dielectrics parallel to the electric field and forming a continuous path between the condenser plates, as shown in Fig. 1B. For this case: E., = AE1 + BE2.........(2) where E., is the dielectric constant of the combination, A is the ratio of the cross sectional area of dielectric E, to the cross sectional area of the condenser plates (assuming the lengths of the dielectrics equal the distance between the condenser plates) and B is the ratio of the cross sectional area of dielectric E2 to the cross sectional area of the condenser plates. As before the constants A and B are the effective "saturation" of the condenser by the two dielectrics. Still another case is described by Lichtenecker5 where dielectric E2 is shown in the form of small particles distributed at random in dielectric E1. This is shown in Fig. 1C. For this case: log Em = A log E1 + B log E2.....(3) where Em is the dielectric constant of the combination. A is the ratio of the volume of dielectric E1 to the volume of the condenser, i.e., the effective "saturation" of the condenser by dielectric E,. B is the ratio of the volume of dielectric E2 to the volume of the condenser, i.e., "saturation" of dielectric El. Equations (l), (2) and (3) are plotted in Fig. 2 for E1 = 2.5 (oil) and E2 = 80 (water). Equations (1) and (2) may he thought of as representing the limiting cases of the configuration of two fluids which might be expected to exist in a porous medium. Equation (3),

Jan 1, 1951

By W. E. Field

In the Coast Mountains approximately 110 miles north of Vancouver, the gold mine of Bralorne- Pioneer Mines Ltd. lies at an elevation of 3500 ft. The deepest or 41 level in the mine is at an elevation of 1400 ft below sea level, and the rock temperature on this level is 122.5°F. The thermal gradient is 1 "F increase in temperature for each 67.5 ft increase in depth. The mine produces between 500 and 600 tons per clay, utilizing an adit two internal shafts, and one service shaft from surface. The Queen shaft, extending from the 26 to the 41 level, IS the deepest, and most production now comes from this area. Stoping in by cut and fill using mill tailing hydraulic backfill.

Jan 12, 1963

By AIME AIME

CONVENTION plans for the A.I.M.E. Regional Meeting to be held on the Minnesota Iron Range Aug. 12 to 1.5 are being completed to give the visiting member?s from all parts of the country a wide variety of technical and recreational features. High spots of the social events are the official dinner, dance, luncheon and golf: and of course, special provision is being, made for the entertainment of visiting ladies. The technical sessions will fit in with scheduled trips to view all phases of mining, beneficiation and transportation of iron ore. Men from the West and Southwest will find much of interest in the detail of the mining operations. A trip to the steel plant of the

Jan 1, 1941

By Joseph Daniels

The Fritz Engineering Laboratory was built under the direction of John Fritz, and presented by him to the University. A view of the building, looking east, is shown in Fig. 1. The building was started in 1909, and completed in 1910, although all of the equipment was not placed until later. Mr. Fritz gave his personal attention to the details of construction and equipment, and it was his custom to drive over every day to the University from his home in Bethlehem and spend some hours watching the work, offering suggestions, making changes, and planning new work. The result is a building and an equipment which embody his practical ideas. The laboratory structure is of the steel mill-building type, of light-colored brick, 91 by 114 ft., of which a section is shown in Fig. 2 and the floor-plan in Fig. 3. The steel frame carries the roof and traveling crane-way. Ample light has been provided by numerous windows in the side and end walls, in the clerestory, and by a skylight 84 ft. long and 9 ft. wide in the north roof. The main aisle of the building is 49 ft. 2 in. between centers of crane-columns, and has a clear height of 40 ft. The remainder of the width is taken up by two side aisles, 18 ft. high. The laboratory consists of four sections: (1) A general testing-section containing the testing-machinery, a small machine shop, and an office; (2) a cement-testing room; (3) a room for making and storing concrete test-specimens; (4) a hydraulic section.

Jan 1, 1912