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By G. Donald Emigh

WESTERN phosphate resources which lie in Ida- ho, Montana, Utah, and Wyoming, have seen great expansion of activity in recent years. Growth has been two-pronged: expansion in fertilizer use, and since 1949, into the elemental phosphorous industry. Elemental phosphorous, produced in the electric furnace, goes largely into chemical making. Phosphate ore was first recognized in the West about 1889. Production started in 1906, and for many years consisted of underground operations by small companies operating sporadically. In 1920 Anaconda Copper Mining Co. opened the underground Conda mine near Soda Springs in southeastern Idaho, and has maintained and increased its operations since then. About 1930 Montana Phosphate Products Co. began underground mining in Montana and has remained a steady producer. In 1945 San Francisco Chemical Co., one of the oldest companies in the western field, initiated strip mining at the Waterloo mine near Montpelier, Idaho, and later at Leefe mine near Sage Junction, Wyo. In1946 J. R. Simplot Co. began open pit mining at Gay mine near Fort Hall, Idaho. In 1950 Victor Chemical Works began underground development work in the area of Maiden Rock, south of Butte, Mont.: and has since mined there. Monsanto Chemical Co. began open pit mining near Soda Springs, Idaho, in 1951.

Jan 11, 1954

By W. A. Backofen, D. H. Avery, W. F. Hosford

Sheets of the magnesium alloys AZ31B, HK31A, and ZE10A in several different tempers were tested in tension and determinations were made of the ratio of width-to-thickness strain. A marked increase in the ratio with tensile straining and a dependence upon alloy and test direction are rationalized in terms of a balance between the amounts of basal and prism-plane slip. All such variations are related, in turn, to the prevailing crystallographic texture. Fracture appearance is explained on the basis of anisotropy in plastic flow, and implications for developing texture -hardening effects in these alloys are discussed. ThE crystallographic texture or preferred orientation of a given material is determined by details of processing history. Such texture is known to influence many aspects of material behavior, in particular both the yielding and strain-hardening characteristics which are of special interest in the present work. Traditionally, the resulting plastic anisotropy has not been regarded as especially desirable. Earing in drawn sheet is perhaps the most common example of an unwanted effect of texture. However, it has also been recognized that suitable textures may be usefully employed to improve drawability,1,2 as a specific example, and generally to control yielding resistance under combined-stress loading.374 Texture would seem to be a detail of structure not yet exploited to nearly the fullest extent. A convenient basis for characterizing anisotropy in plastic behavior is the ratio of width-to-thickness strains obtained in a tension test;5&apos;6 the parameter is frequently labeled "R" and its value is revealing with respect to the nature of the prevailing texture. R gives a useful measure of a material&apos;s "thinning resistance". For an isotropic material, R = 1. With R > 1 the increased through-thickness strength in a sheet means greater resistance to yielding under biaxial tension, or "texture hardening";3&apos;4 if R < 1 the result may be a "texture softening" under the same loading conditions.4 Most R data relate to steel sheets for deep-drawing applications. Values for steel and other materials of cubic structures are not often much greater than 1 and nearly constant with strain in testing.1,2,7,8 To explore the implications of plastic anisotropy further, it was felt that experiments with much more strongly textured materials would be useful, and this led to the choice of magnesium alloys. The "ideal" sheet texture for magnesium contains the (0001) plane in the rolling plane, which ought to lead to R values approaching infinity. However, departures from the ideal texture, the possibility of slip in non-close-packed directions, and deformation by twinning would all be expected to introduce some range of R. Accordingly, studies on these materials were undertaken. EXPERIMENTAL Alloys in sheet form, Table I, were selected to obtain a variation in crystallographic texture, in the expectation that this would be reflected in differences in plastic anisotropy. Pole figures constructed by the Schulz surface-reflection technique9 were provided with the experimental materials by the Dow Metal Products Co. Profiles of pole density along great circles through the rolling (0 deg) and transverse (90 deg) directions were prepared from the pole figures and are collected in Figs. 1 and 2; considerable departure from the "ideal" (0001) alignment in the rolling plane is evident, with the largest angular spread in both directions being found in the ZEl0 alloy. Results of tensile tests on full-thickness specimens of 6-in. gage length by 1/2-in. width are given in Fig. 3 as engineering stress-strain curves* in rolling and transverse directions. All tests but one were made at a constant drive rate of 0.02 in. per min, and the final values of percent elongation at fracture, over the initial 6-in. gage length, are noted at the ends of the curves; one test on ZE10A-

Jan 1, 1965

By R. W. Raymond

There is apparently no end to the doubts, inconsistencies and absurdities in which the courts of our mining States and Territories are involved in their attempts to apply to conditions of ever-increasing complexity the provisions of our anomalous mining law. In previous papers, I have called this statute " the law of the apex," because it based upon that vague, novel and mysterious condition the most important grant of title. But the apex is scarcely a more essential feature than the end-lines and the side-lines; for the rights which it may confer may be limited in various ways by these; so that we have, in many a case, the most ridiculous result that the United States, in return for the money of a citizen, conveys to him with much solemnity, under its broad seal, nobody knows what, bounded nobody can tell how. A decision recently made at Butte by Judge De Wolfe, of the United States District Court of Montana, in the case of King et al. vs. The Amy and Silversmith Mining Company, furnishes a fresh illustration of this criticism. The diagram on the following page, constructed without precise regard to courses and distances, simply to assist in the statement of the essential features of the case, will, 1 hope, make clear the principles . involved : The plaintiff occupies a location (the Nonconsolidated) adjoining on the north the defendant&apos;s location, a b c d (the Amy), and the disputed mining-ground lies, let us say, in depth under the point W, that is, on the dip of the vein, VD, but not under the surfacelocation, a b c d. The defendant has the prior title, and claims this ground under its extra-lateral right. It is admitted that the apex does not cross the end-line, a d, and does cross the side-line, a b. Whether it crosses, at the other end of the location, the end-line, b c

Jan 1, 1889

By MARSHALL D. DRAPER

CHINA is one of the large producers of the world&apos;s tin. About 95 per cent of the total Chinese production comes from the Kotchiu district in the southern part of the province of Yunnan. Yunnan occupies the southwestern part of China, bordering on Burma,. Siam and. French Indo-China. From the British port of Hong Kong,&apos; small steamers sail southwest at about four-day intervals, reaching Haiphong in French Indo-China in two or three days. This, one of the principal ports in Indo-China, is a modern French city of some 50,000 population which, with its tropical surroundings, has much natural beauty. It is a few miles from the sea on the Red River, which has its source in China. Both at Haiphong and Hanoi, the capital of Indo-China, sixty-three miles north of Haiphong and also on&apos; the Red River, there are foundries, shipyards, machine shops, cement and brick plants and various similar industries.

Jan 1, 1931

By Henry D. Hibbard

I. INTRODUCTION. THESE impurities are perhaps the most important things in steel-especially steel made by the oxidation processes-the effect of which has not been at least approximately determined. By oxidation processes I mean the Bessemer and Siemens-Martin, during which the metalloids in the charge are removed by oxidation. It has been truly said that it is a clear advantage to have a new name for a new thing. To secure this and to economize space, let us adopt the name sonim (plural sonims) to designate the solid non-metallic impurities existing in steel or other metal. I would define a sonim as a solid non-metallic portion of matter existing as an impurity in metal. A piece of sand, brick, clay, or such material, imbedded in metal, would be considered as a foreign body, not as an impurity, and therefore not a sonim. The studies of sonims of which the results have been published hitherto, have been made chiefly or wholly on finished or at least on cold steel, without much, if any, regard to the specific methods by which the steel was made. While many of the results so obtained are valuable, they give little help in determining the cause, effect, or cure of the disease. It is not enough, in such a study, to know merely the commercial name of the process; for within the field of each process lies a great number of possible variations, each of which will yield a result differing in some respect from all others; and the control of sonims is particularly dependent. on the metallurgical treatment of the metal, because of the inability of analytical chemistry to throw much light on their presence, condition, and effect, as they usually occur in commercial steels. The microscope aids more, perhaps, than chemistry in their study.

Apr 1, 1911

By Eugene A. Stephenson

The writer apologizes for presenting this very elementary analysis of one aspect of proration, but a search of the literature failed to disclose any concrete illustrations of the effect of various proration formulas upon the allowable oil produced by tracts of different sizes. Many engineers have doubtless made somewhat similar calculations and are fully acquainted with the results. The various allocation formulas that are in use are based on one or more of the following factors: (1) wide-open well potential, (2) potential through an orifice, (3) uniform well allowable, (4) acreage, (5) sand thickness, (6) bottom-hole pressure, (7) productivity index, and (8) volumetric displacement. Of these, the unrestricted potential formula, or open-flow test, and the uniform well allowable are commonly regarded by engineers as those least likely to give each producer his proportionate share of the oil or gas, as represented either by acreage or by sand thickness, or both, except when the wells are located on tracts of large size. Unless the mechanical equipment that may be used during the potential test and the method of taking the test are both specified, the net result of the potential formula is to practically force the operators to use special equipment and adopt special procedures prior to and during the potential test, so as to secure the largest possible allowables. Much ingenuity and skill have been devoted to this,problem, but the general effect is to permit excessive allowables for very small tracts, and stimulate unnecessary drilling. It is interesting to compare some of the high yields from the Wilcox horizon at Oklahoma City with each other, as an illustration of the effect of an allocation factor based solely on potential (Table 5). One of the glaring instances is a well on a ½-acre lease, which had produced, as of September 1936, at the rate of almost 3,000,000 bbl. per acre. This is at least twice as many barrels as could have been present under the property if the reservoir had consisted of a tank of oil 200 ft, deep and 56 acre in area. Numerous combinations of acreage, potential, bottom-hole pressure, sand thickness, etc., have been proposed and are in use in various fields.

Jan 1, 1937

By L. G. Truby

This paper presents the results obtained after calculating matches of the observed pressure performance of five fields completed in a common aquifer. A general dejcription of the Central Basin Platform area in West Texas in which the five fields, Andector, Embear, Martin, TXL, and wheeler, are lo. cated is contained in the paper. The method of utilizing the electric analyzer to calculate simultaneously matches of the observed pressure performance of the five fields is outlined. The determination of boundaries of pressure communication is discussed and the extent of pressure interference between fields consistent with the configuration of the area aquifer is shown graphically. INTRODUCTION Anomalies in the pressure performance of the Andeector Ellenhurger Field resulted in an investigation of pressure interference between several Ellenburger fields located on the Central Basin Platform in West Texas. Four fields, Embar, Martin, TXL, and Wheeler, were found to contribute significantly to the pressure drawdown at Andector. An initial investigation of the pressure performance of the Andector Ellenburger Field revealed that the reservoir pressure could not be matched by the calculation technique usually applied to water drive reservoirs. In the past, many have advanced the opinion that fracturing in the Ellenburger was a local condition restricted to the immediate uplifted area around the field, in which case each field would in all probability be surrounded by its own relatively small aquifer. Following several unsuccessful attempts to account for the pressure performance at Andector, a system assuming a common aquifer involving several fields in the immediate vicinity of Andector was placed on the electric analyzer and the effect of lo. interference was noted. A refinement of the initial analyzer calculations involved the determination of the approximate boundaries of the aquifer, the calculation of detailed matches of the pressure performance of the interfering fields, and an evaluation of the degree of communication between fields. DISCUSSION Geology and Development The fields considered in this work are located in the Central Basin Platform, a north-south trending structural feature in West Texas lying between the Delaware Basin to the west and the Midland Basin to the east. The locations of various individual Ellenburger fields in this general are shown in Fig. 1 with the five major fields which appear to be definitely intercommunicating colored in black and located in the circled portion of the figure. Production from the five fields was first obtained from the Embar Field discovered in July 1942, followed by the Wheeler Field in 1943, the TXL Field in 1945, and the Martin and Andector Fields in 1946. The total reservoir fluid production from these fields is indicated in Fig. 2. As illllstrated in this figure, very little production was taken from these fields prior

Jan 1, 1952

By F. H. Labee

Questionnaires and special letters soliciting information were sent to a great many geologists, petroleum engineers, independent operators, and representatives of large companies in Arkansas, Louisiana, Texas and New Mexico. Replies to more than 50 per cent. of these letters were received. A survey of the facts and opinions presented in this correspondence will be made a little later, but first some of the general aspects of the problem will be reviewed. By "unit operation,"1 we mean the development and operation of a single entire pool, or reservoir, of petroleum by one management, on a systematic and scientific plan which is best calculated ultimately to extract from the pay sand and bring to the surface of the ground the largest possible amount of oil with the greatest possible total profit. No one, as far as the author has been able to ascertain, denies the advantages, both scientific and practical, of unit operation. All are agreed that it is sound in theory. It permits the proper distribution of wells, which should always be spaced on the ground according to a regular geometric plan with the intention of maintaining the same spacing all the way down and into the pay sand, or pay sands. This spacing will be different for different fields, depending on such variable factors as the lithologic character of the pay formation, the nature of the controlling structure, the depth of drilling, the viscosity of the oil, and so on. From the viewpoint of engineering practice, as applied to economical extraction of oil, there is no more important consideration than well spacing—well spacing in the pay formation, and not merely on the surface of the ground —for the method of well spacing has a direct bearing upon all such engineering practices as pressure control, repressuring by gas, the water drive, and SO on. H. C. Miller2 summarized the advantages of an ideal cooperative development plan as follows: "Among the more important advantages of

Jan 1, 1930

By Edward C. Stephens, Robert R. Coats

High-grade copper ore was discovered in 1932 in the long-dormant Mountain City (Cope) mining district, Elko County, Nevada. From 1932 to 1947, the one producing mine in the district, the Mountain City Copper Mine, produced 1,109,878 short dry tons of ore averaging 9.745 per cent copper, 0.274 ounces of silver, and 0.0057 ounces of gold per ton. The Mountain City Copper Mine is developed in eugeosynclinal rocks of Ordovician age, the Valmy Formation, which is part of the upper plate of the Roberts Mountains thrust. On the Valmy were deposited unconformably first, a elastic formation of Devonian or Mississippian age, the Grossman Formation, succeeded unconformably by a ·sequence of three conformable formations, the Banner, the Nelson, and the Mountain City. The Banner Formation probably is early Late Mississippian in age; the ages of the Nelson and Mountain City are not known precisely but are believed to be of Late Mississippian and Carboniferous(?) age, respectively. A thick formation of elastic rocks, limestone, and volcanics, the Reservation Hill Formation, has been thrust over the Mountain City. The age of the Reservation Hill is unknown but is presumed to be Pennsylvanian(?) and Permian(?). Several plutons of Cretaceous quartz monzonite intrude the Paleozoic formations; they and the intruded formations have been laid bare by erosion, and several sequences of volcanic rocks of Miocene and Pliocene age, and perhaps in part older, have been successively deposited on irregular erosion surfaces. The primary mineralization of the Mountain City Copper Mine is believed to postdate the deposition of the Nelson Formation and to predate the intrusion of the quartz monzonite. The primary ore bodies are lenticular in shape and are composed largely of quartz, pyrite, and chalcopyrite. The ore lenses, in general, strike northwestward and dip northward. They occur in the Valmy Formation within a definite stratigraphic sequence composed largely of shales with associated minor quartzite lenses. The ore is epigenetic. The principal ore body, the "200," was completely leached to the 200 level. Abruptly beneath the barren gossan was supergene copper sulfide ore, much of which assayed 50 per cent copper. The secondary copper minerals are sooty and massive chalcocite, bornite, and covellite. The supergene enrichment of the ore may have required a large part of Tertiary time.

Jan 1, 1968

By Heath B. Fowler

The surface mining operations of the Simplot Fertilizer Co. are on the Fort Hall Indian Reservation approximately 16 miles east of Fort Hall, Idaho (Fig 1). The Phosphoria formation outcrops in sec. 2, 3, 11, 14, 15, 22 and 27, T 4 S, R 37 E, Boise Meridian. The ownership of these phosphate-bearing lands is divided between individual Indians and the Bannock-Shoshone Tribe, and the royalties are paid to the respective owners on a tonnage basis, as the rock is mined. The geology and mineral resources of the Fort Hall Reservation were studied by the U. S. Geological Survey in 1913 and reported on in 1920. † However, it was not until the winter of 1945 that exploratory work was undertaken by private enterprise. Diamond drilling was begun by the Simplot Fertilizer Co. in April 1946, and stripping operations were started in June. A camp was established near

Jan 1, 1950

By Northcutt Ely

This chapter deals with the systems of laws by which governments regulate the exploration for and production of the minerals within their jurisdictions. It is a summary, restricted by necessary space limitations, of material assembled by the author for a publication of the United States Bureau of Mines, "Summary of Mining and Petroleum Laws of the World," (Information Circular 80 1 7, 196 1. ) The present study is organized in three parts, dealing with (1) the historical background of these legal systems, (2) laws of the United States, and (3) laws of other countries of the world. The reader&apos;s attention is invited to the acknowledgments at the end of the chapter, which inadequately express the appreciation due those who have assisted in the collection of this material. Part I. Historical Development of Major Western Systems of Land Tenancy with Respect to the Ownership and Control of Minerals The use of metals in primitive societies was largely confined to the manufacture of weapons for self-preservation. The ruler&apos;s control over copper, then bronze, then iron, was essential to maintenance of his own ascendancy at home and his group&apos;s position against neighbors who had access to similar metals. Ancient societies were thus characterized by the ruling group&apos;s ownership of minerals and metals. The Egyptian civilization, which emerged in the fourth millenium B.C. upon the agricultural subjugation of the lower valley of the Nile, was responsible for extensive development of the upper valley as a source of mineral wealth. The production of gold during the height of that civilization has been estimated at $30,000,000 per year, thus equaling the early placers of California and Australia. The mines of Egypt were the property of the Pharaohs and were controlled at their direction. Greek mining developed a different scheme of land tenancy which more closely resembled modem concepts. Development of mineral resources was

Jan 1, 1964

By John L. Boardman

The Anaconda company has never indulged in any employee activities at Butte which might be termed paternalistic, but it has exerted a vast amount of effort in care of its employees during working hours. The reason for this policy is not lack of interest or that the company does not feel the effect of employees&apos; activities while they are "off the job"; it is that the company and the city of Butte have grown up together and each has been adequate in its own sphere, the company in providing employment at the highest possible wage and the city in providing housing, sanitation, commercial services, medical services, schools, churches, amusements and entertainments. The one exception to this independence between the company and the community is the Butte Water Co., which is a wholly owned subsidiary of the Anaconda Copper Mining Co. Mention of this relationship is made here because the water supply of such a city as Butte is one of the principal factors in determining the health of the people. Very early in the development of the Anaconda company an adequate and dependable water supply for the operations became necessary, therefore the company took over this important community function. So well has this activity worked out that during the whole period of time covered, in which the company has expanded to become practically the sole mine operator and the community has grown from a small mining camp to the status of a modern city, there has been no shortage of water or any outbreak of water-borne, epidemic disease. Conditions Leading to Organized Safety Effort A brief sketch of conditions in Butte prior to 1912 is necessary to an understanding of the reasons for placing accident prevention on an organized basis. As early as the year 1884 there were a large number of small independent mining operations depending principally upon the production of silver, although even then copper was becoming prominent in the value of total production for the district. The Butte camp was then just emerging from the log cabin stage to that of a modern city.

Jan 1, 1940

By John L. Boardman

The Anaconda company has never indulged in any employee activities at Butte which might be termed paternalistic, but it has exerted a vast amount of effort in care of its employees during working hours. The reason for this policy is not lack of interest or that the company does not feel the effect of employees&apos; activities while they are "off the job"; it is that the company and the city of Butte have grown up together and each has been adequate in its own sphere, the company in providing employment at the highest possible wage and the city in providing housing, sanitation, commercial services, medical services, schools, churches, amusements and entertainments. The one exception to this independence between the company and the community is the Butte Water Co., which is a wholly owned subsidiary of the Anaconda Copper Mining Co. Mention of this relationship is made here because the water supply of such a city as Butte is one of the principal factors in determining the health of the people. Very early in the development of the Anaconda company an adequate and dependable water supply for the operations became necessary, therefore the company took over this important community function. So well has this activity worked out that during the whole period of time covered, in which the company has expanded to become practically the sole mine operator and the community has grown from a small mining camp to the status of a modern city, there has been no shortage of water or any outbreak of water-borne, epidemic disease. Conditions Leading to Organized Safety Effort A brief sketch of conditions in Butte prior to 1912 is necessary to an understanding of the reasons for placing accident prevention on an organized basis. As early as the year 1884 there were a large number of small independent mining operations depending principally upon the production of silver, although even then copper was becoming prominent in the value of total production for the district. The Butte camp was then just emerging from the log cabin stage to that of a modern city.

Jan 1, 1940

By A. Ross Rornmel

ABILITY to speak effectively is one of man&apos;s most longed for and coveted abilities. It is the ability to stand on one&apos;s feet, transfer knowledge and thoughts to others, to reach an objective professionally or otherwise by leading groups through a channel of planned thought. Each day group speaking plays an important part in making or marring success, and the engineering profession often provides this opportunity and requirement. An ability to speak effectively develops courage, poise, confidence, and prestige for the speaker. The technical man cannot be reluctant to face an audience. He is often called upon to do this in presence of employees, supervisors, and other groups. His ability to speak effectively is as much a requirement as the fundamentals of his profession. The three fundamentals of effective speaking are: (1) Enthusiasm and Confidence. These are joined because of their close relation. (2) Preparation. This includes knowledge of the subject. (3) Presentation. By this is meant the features of delivery.

Jan 1, 1946

By Gordon B. Brox, Joseph F. Mcaleer, Charles C. Goddard, Edward P. Shea, Robert G. Ingersoll, Lester G. Zeihen, George J. Burns, John M. Guilbert, Richard N. Miller, Charles Meyer

The Boulder batholith is a composite intrusive in which the Butte quartz monzonite is the dominant rock type. Quartz porphyry dikes intruded the quartz monzonite in directions which were subsequently followed by the eastwest- striking Anaconda system of veins, the earliest major veins in the district. Anaconda veins are faulted by northwest-striking veins of the Blue system, which are most prominent in the central third of the district. Anaconda veins are the major producers in the western third of the district and also in the eastern third, where the "horsetail" zones break off from them. Individual oreshoots are thousands of feet long as well as deep on both systems of veins, but they are generally more persistent and thicker on the Anaconda veins. Viewed broadly, the mineralization in the big veins is arranged in crudely concentric zones of zinc and manganese around a central zone of copper. Only slightly offset from these zones, but earlier structurally, is a zone in which quartz-molybdenite veinlets are prominent. This zone tops at about the 2800 level and widens downward. The pattern of distribution of Cu-Fe-S series minerals in the large veins of the copper zone is not symmetrical with respect to the metal zones. There is a fringe of chalcopyrite-bornite all around the copper front. However, within the copper zone, pyrite-chalcocite-enargitecovellite- digenite assemblages are prevalent near its eastern edge from the 3800 level to the surface, whereas deep on the large Anaconda veins in the western part of the copper zone, chalcopyrite is dominant. Here the chalcopyrite grades upward into bornite-chalcocite ores and eastward into the high-sulfur assemblages of the Leonard mine. Sericite-biotite-K-feldspar alteration envelopes, containing up to about 2 per cent copper as chalcopyrite, are present on some of the quartz-molybdenite veinlets at deep mine levels in the molybdenite zone. These envelopes contrast sharply mineralogically and chemically with the later sericitic and argillic alteration envelopes around Main Stage veins. K'0-Ar'0 ratios indicate that they may be older by about 4 m.y. Secondarily enriched copper ores are mined in the Berkeley pit in the southeastern part of the district. At the present time they account for about half of Butte's production of copper.

Jan 1, 1968

By L. G. Sprague

THE fact that this latest and most modern of the Universal Atlas Cement Company&apos;s plants at Northampton, Pa., is the fifth to be built on these same properties, and their development has been coincidental with the development of the portland cement industry in the United States, makes it appropriate to sketch briefly the history of the successive steps. In 1889 the original Atlas Portland Cement Co. started its first plant at Coplay, Pa., which is just across the Lehigh River from the present operation. Here the first successful rotary kiln was operated. These kilns were 6 ft. in diameter and 60 ft. long; they used oil for fuel until 1895, when the company developed the first burner for pulverized coal. Shortly thereafter the Atlas company acquired property on the Northampton side of the river and built its plants Nos. 2, 3 and 4 within the following 10 years. During the same period the production of portland cement in the country was increasing rapidly; owing largely to the development of the rotary kiln and improved grinding machinery, which lowered the cost and improved the quality of cement. The general tendency has been to increase the length of the kiln and grind both raw material and finished product finer. In 1930 the Atlas Portland Cement Co. and the Universal Portland Cement Co. united to form the Universal Atlas Cement Co., and the same policy of improving the product has been continued. Because of the large amount of research carried on by manufacturers and consumers, including government agencies, there is a demand for cement of different chemical and physical characteristics for different kinds of structures. Hence many engineers in recent years have been asking for cements of certain definite chemical analyses, which they think are best for their particular jobs. This has compelled the manufacturer to make several different types of cement by variations of chemical composition. These are generally made by adding silica, iron and lime to the standard mixture, which necessarily increases the cost of the product. Therefore the Universal Atlas Cement Co., in planning the modernization of its Northampton plant, gave this particular phase of the problem considerable study. Research and experimentation have developed the practicability of making a wide variety of differently proportioned raw materials for cement by a process of subtraction rather than by addition. With such process, it is possible to discard the undesirable aluminates and silicates from the ample supply of impure limestone available from the company&apos;s property rather than by adding high-grade limestone obtained from distant sources. This procedure requires mineral separation by centrifugal sedimentation and froth flotation. Since the chemical and mineral constituents of Lehigh Valley "cement rock," together with the methods of separating them, have been thoroughly described in published

Jan 1, 1943

As described in the section on the Palabora twin crushers, the Palabora ore consists of two types: a carbonatite containing a low titanium magnetite, and a foskorite containing high titanium magnetite. As the Palabora pit was widened and deepened, more and more of the foskorite had to be mined. The 25,000 mt expansion of the Palabora plant which went into operation in early 1977 therefore takes its feed from the foskorite section of the orebody. For the expansion, a third 54 in. by 74 in. gyratory crusher was installed to crush feed for two 32 ft by 15 ft (9.75 by 4.6 m), 9000 hp (6710 kw) autogenous single -stage grinding mills. These units are located near the two existing primary crushers, and the ground ore is pumped 5277 ft (1640 m) to the expanded flotation plant by five stages of centrifugal pumps. The new gyratory is installed in a unique Figure-8 shaped enclosure with the crusher in the smaller 27 ft 11 in. (8. 5 m) diameter cylinder and the maintenance area in the 36 ft 1 in. (11 m) diameter cylinder. Cylinder walls are only 23.6 in. (600 mm) thick because their circular design permits all the concrete to be in compression. A rectangular dump pocket which sits on the smaller cylinder contains two manganese steel faced splitters to protect the crusher spider and countersunk water spray headers under the dumping positions for dust suppression. The dump pocket holds 330 st or 300 mt and is also lined with manganese steel. The crusher is mounted on a reinforced concrete diaphragm over the 363 st (400 mt) crushed ore pocket. In the back of the pocket is plastic pipe. Radioactive level control sources are lowered into this pipe from the crusher support floor. The pipe is protected by concrete covered with steel castings. Level control detectors are mounted on the front wall of the pocket. Liner plates on the crushed ore pocket walls are removed and in- stalled by the use of a circular monorail and trolley mounted on the pocket ceiling. The door in the front of the crushed ore pocket is hinged at the top rather than at the sides and is raised by an electric winch. For removal of the eccentric, rails are installed in the pocket and a unique hydraulically operated cart is moved under the eccentric. A platform is raised to receive the eccentric and lowered so that it may be removed. Crushed ore is removed from the pocket by a hydraulically powered, 8 ft

Jan 1, 1978

By Robert Goodwin, Frank R. Milliken

IN September 1939, the Ohio Copper Co. inaugurated the treatment of its copper-bearing mill tailings at Lark, Utah. These tailings had been accumulated during the regular operation of the Ohio Copper mine and mill over the period 1907 to 1919. Gravity concentration had been employed except for a comparatively short period in 1919, when flotation was used. The ore milled during that period assayed about 1 per cent Cu. The chief copper mineral, chalcocite, was disseminated in a shattered quartzite, mainly along fracture or cleavage planes. The quartzite gangue was extremely hard and grinding to liberation resulted in excessive sliming of the "sooty" chalcocite, with consequent high tailings losses. Recovery on the seven million tons treated was probably less than 6o per cent of the total copper content. As early as 1918, attempts had been made to sample the dump. In 1928, a complete sampling program was undertaken. The sampling consisted of seventy-four 5-in. post auger holes drilled to the full depth of the dump at regular intervals of 250 ft. Each 10-ft. portion thereof comprised a sample for analysis. Each sample was screened, rolled, divided into three parts, dried and assayed. The reject was retained for testing purposes. From the depth of the auger holes a contour map of the dump was plotted, Fig.1, which gives percentages of tonnage and copper content. The tonnage within the limit of the drill holes was estimated at about five million tons with an average content of 0.42 per cent Cu, 31 per cent of which (0.13 per cent) was acid-soluble. A screen analysis of the composite dump sample is shown in Table I. Flotation tests by several companies and individuals were then made, the results of [ ] which ranged from 62 to 74 per cent recovery. On the basis of these, a Zoo-ton pilot plant employing straight flotation was built and operated for a few months. Operation of this plant was unsuccessful, as no provision had been made to handle the copper-bearing solutions resulting from the water-soluble copper, a point that was overlooked in the laboratory test work. Attempts to decant the copper-bearing solution for precipitation in the usual manner ahead of flotation were not satisfactory because of low water recovery (owing to poor settling characteristics of the pulp) and contamination of the copper precipitate with unsettled slime. Low copper prices in 1931 necessitated the termination of testing. With the stimulus of higher copper prices in 1937, a review was made of metallurgical

Jan 1, 1940

By W. M. Peirce, R. K. Waring

Zinc of high purity offers definite advantages in certain fields. A process by which zinc of 99.99 + per cent purity is produced by pyro-metallurgical methods is described in this paper. The process consists of a fractional distillation following the primary reduction; this fractional distillation employs the principles of rectification for the separation of lead and other high-boiling impurities and cadmium and other low-boiling impurities. Theoretical Considerations Involved in Production of High-purity Zinc by Distillation Fractional distillation, fractional condensation, and rectification are recognized methods of separating mixtures of liquids. In the field of organic liquids these methods are widely used but not commonly to effect as complete a separation of liquids as is done in the problem under consideration. Zinc boils at 905" C., cadmium at 778" C. and lead at about 1620" C. Zinc may contain from several hundredths of one per cent to over one per cent each of cadmium and lead, and the problem is to reduce these impurities to a few thousandths of one per cent. For lead and zinc, the spread in boiling points is substantial, 715° C., while for zinc and cadmium it is only 127" C. The basic limitation of any separation by distillation may be found from the relation between the equilibrium composition of the vapor and the liquid for all mixtures of the two substances involved. If a mixture of constant boiling point is found, or if a stable compound that vaporizes without dissociation occurs, there is a definite theoretical limit to the degree of separation that is possible when operating at atmospheric pressure with respect to that mixture. Otherwise, any degree of separation is theoretically possible. The equilibrium composition of vapor in contact with liquid mixtures of zinc and cadmiurn at the boiling point has been determined experi-

Jan 1, 1937

By H. Foster Bain

(San Francisco Meeting, October, 1911.) [SECRETARY&apos;S NOTE.-This paper, presented in oral abstract, at the San Francisco meeting, was not at first supposed by Mr. Bain to be required for publication in the Transactions; and the excursion to Japan, in which he took part, immediately after the San Francisco meeting, delayed his presentation of the manuscript. After his return to San Francisco, Mr. Bain, in view of the importance of his paper and its discussion, kindly furnished it in full. The delay in its publication (since it was received in April last) has been due, partly to the circumstance that other contributions had meanwhile acquired the "right of way," and partly to the consideration that, the situation contemplated in Mr. Bain&apos;s paper having remained practically unchanged, the paper and its discussion would not lose force or timeliness by this lapse of time.-J. S.] No acute observer of public affairs can have failed to observe a growing disposition on the part of the public to change emphasis in government from political equality to social justice. When our own government was founded it was felt to be sufficient to secure to each individual the fullest possible freedom of opportunity, and such a scheme was excellently adapted to the rapid development of a large territory having a small population. As the number of people in a given area increases, there are more points of contact and conflict; each must move in a smaller orbit, and there must be more regulation. Germany is making faster progress in industry than is any other country. The principal reason is the insistence there on team-play. In Germany there are fewer multimillionaires and more socialists (spelled with either a big or little " S ") than in any other of the leading countries; but Germany wins trade and is steadily improving the conditions of life for her citizens. To some, the change from the freest individualism is welcome; to others it is intensely unacceptable. To this fundamental difference in view-point may be imputed much of the vigor with which the controversy regarding coal-lands has been waged. That present conditions in Alaskan coal-fields are extremely unsatisfactory is generally recognized, but there are wide dif-

Aug 1, 1912