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By H. S. McKnight

One phase of Canada's rapid development in mining and metallurgy during the past few years has been the creation of Canadian Copper Refiners Ltd., and the establishment of its modern electrolytic copper refinery at Montreal East, Quebec. Canadian Copper Refiners Ltd. is made up of three well-known metal firms whose combined activities cover the entire industry from the mine to the market. They are Noranda Mines Ltd., Toronto, Nichols Copper Co., New York, and British Metal Corporation, Ltd., London. Noranda Mines is the principal owner and provides the greater part of the raw material received by the refinery for treatment. Nichols Copper Co. designed and built the plant and is operating it under contract. British Metal Corporation acts as sales agent and markets the refinery's products. Montreal East was chosen as the site of the new refinery only after a careful survey had been made of the entire eastern part of Canada. The location chosen offers many advantages, chief of which arc the relatively low costs of power, labor, fuel and bupplies, and the fact that it is situated on Montreal harbor, the nearest seaport to the points of origin of the ram materials. All incoming material is received by rail. A majority of the plant's product is exported through the port of Montreal to European markets, being handled to the docks in railroad cars. A large proportion of the product is delivered by means of an industrial railway to the adjacent rolling mill of the Canada Wire & Cable Co., Limited. The refinery was designed to treat primarily the copper produced by Noranda Mines, Ltd. and Hudson Bay Mining &. Smelting Co., Ltd., and its rated capacity is 75,000 short tons per year. A general layout of the plant is shown in Fig. 1. Its capacity can be readily doubled, as shown by the dotted lines. Figs. 2 and 3 are sections taken through the furnace department and the tank house respectively. Except for the main office and laboratory and an auxiliary building containing the stores, warehouse, change rooms, compressor room and machine shop, the entire plant is under one roof. The type of building construction consists of reinforced concrete foundations supported on concrete piles, a steel structure covered with Robertson Protected Metal siding and a 3-in.

Jan 1, 1934

By P. Somasundaran, I. J. Lin

There are several methods described in the literature for the determination of the order and the rate constant for the flotation of minerals. These often involve some type of computational or graphical procedures. A relatively simpler method developed on the basis of a technique used by Chang" in chemical kinetics is described in this paper. Chang's technique, like most others in chemical kinetics," is based on the law of mass action which states that the rate of a chemical reaction is proportional to the active masses of the reacting substances at any given time. Application of this law to the flotation of minerals would involve the adaptation of the terms "flotation" for "chemical reaction" and "floatable amount of the minerals" for "the active masses of the chemical reactants." There are indeed a large number of physical processes controlling the actual flotation rate. The most inefficient one of these could be considered equivalent to the slowest reaction in a series of chemical reactions. If variables such as aeration rate and agitation are kept at constant levels, the rate of flotation under free flotation conditions (i.e., conditions under which the suspension is dilute) will be given by the following equation: where C is the concentration of the floatable minerals in the pulp at any given time t, K is the rate constant, and n is the order of the reaction. If we represent the floated fraction of the floatable mineral at time t as m (0 m - 1) and C at t = 0 as Ca, integration of Eq. 1 yields

Jan 1, 1974

By Vernon Read, John K. Hayes

Generally speaking, drilling equipment and techniques presently in use are not capable of meeting the complex technical-and economic-requirements of deep core drilling. Drilling to great depths involves increasing risk, time, and money. And it is especially true that costs increase with depth when conventional core drilling methods are used. Introduction of wire-line drilling techniques has been a great boon to deep core drilling, and is rapidly gaining general acceptance. But, in spite of recent progress, there remains a great need to improve productive drilling time and penetration rates, and still maintain high core recoveries.

Jan 1, 1959

By Edmund Newton

The steel industry of the United States has depended in the past almost wholly upon imports for its supplies of manganese. Many of the important domestic sources yield ores leaner in their natural condition than the foreign ores the steel industry. has been accustomed to use. To make them available, therefore, either the ores must be concentrated or the practice of the steel industry modified. Roughly 25,000 T. annually of high-grade manganese ores are used for dry batteries for chemical purpose, and in other ways; while approximately 750,000 T. are required for making steel. , By present practice, every ton of steel takes an average of about 14 lb. (1.8 kg.) of metallic manganese. This is generally added to the steel in the form of an alloy, the standard alloys being the 80-per cent. ferro-manganese and the 20-per cent. spiegeleisen, During the year 1917, 286,000 T. of ferromanganese and 193,291 T. of spiegeleisen were made in this country, the former largely from imported ores; and 45,381 T. of ferromanganese. was imported. The metallic manganese represented by these alloys was 304,000 T., the product of roughly 800,000 T. of high-grade ore and 345,000 T. of low-grade ore. Manganese Deposits in the United States Before the war manganese ore was mined in relatively small quantities in the Appalachian region, including Virginia, Tennessee and Georgia, and in Arkansas, but owing to the increase in prices during the past three years manganese mining has been undertaken also in Montana, California, Arizona, New Mexico, Nevada, Utah, and Minnesota. From data now available it appears that in this country deposits of high-grade manganese ores are usually small, while materials lower in manganese and higher in iron occur in appreciable quantities. Our total quantity of manganese-bearing material is relatively large, but on

Jan 1, 1920

By J. L. Gillson

In a brief summary of the many occurrences of fluorspar in our western states, it is not possible to go into detail in regard to the geology, mining and milling methods, and reserves about individual deposits. Rather a broad review is made of the occurrences and an analysis of how the western deposits may fit into our future domestic economy is presented. General Statement on Fluorspar Situation Fluorspar has been used for years as a flux in the manufacture of basic open-hearth steel, in foundry cupolas for melting pig iron, in the manufacture of opalescent glass and in the preparation of hydrofluoric acid. In 1880 the annual production of fluorspar in the United States was around 4000 tons per year. By 1900 it was up to 21,656 tons and between 1902 and 1908 it averaged about 40,000 tons annually. Prices were then so low, by present standards, that it seems impossible to believe now that mining could have been performed profitably at the price levels then prevailing. In 1890 fluorspar sold at the mines for $6.70 per ton, in 1901 for $5.81, in 1916 for 85.92. When the United States entered World War I, flyorspar production and price skyrocketed; the production reached 263,817 tons in 1918, with prices above $20.00 per ton, and prices were even higher in 1919 and 1920. After 1920, the domestic production fell from the 1918 level to about 125,000 tons annually and the average price dropped back to about $18.00 per ton. By 1935 the average price had fallen to $15.00, but in 1940 with a rising demand the average price of all grades had gone back up to $20.31. Today it is 75 per cent higher than in 1940 and presumably the price of acid grade at .least would be even higher if it were not for price ceilings. The first subsequent year that the domestic production exceeded that of 1918 was 1941, and the 1944 production is expected to exceed 400,000 tons, or over one and a half times that of 1918. In five-year periods, average production and imports were as are shown in Table I. Many people concerned with the consumption of fluorspar believe that the postwar period ahead will show a repetition of price trends of the last such period. They believe that imports will be again an important factor in the available supply and the price will fall back gradually toward the prewar level. The following basic factors are pertinent in analyzing this conclusion:

Jan 1, 1948

By J. L. Gillson

In a brief summary of the many occurrences of fluorspar in our western states, it is not possible to go into detail in regard to the geology, mining and milling methods, and reserves about individual deposits. Rather a broad review is made of the occurrences and an analysis of how the western deposits may fit into our future domestic economy is presented. General Statement on Fluorspar Situation Fluorspar has been used for years as a flux in the manufacture of basic open-hearth steel, in foundry cupolas for melting pig iron, in the manufacture of opalescent glass and in the preparation of hydrofluoric acid. In 1880 the annual production of fluorspar in the United States was around 4000 tons per year. By 1900 it was up to 21,656 tons and between 1902 and 1908 it averaged about 40,000 tons annually. Prices were then so low, by present standards, that it seems impossible to believe now that mining could have been performed profitably at the price levels then prevailing. In 1890 fluorspar sold at the mines for $6.70 per ton, in 1901 for $5.81, in 1916 for 85.92. When the United States entered World War I, flyorspar production and price skyrocketed; the production reached 263,817 tons in 1918, with prices above $20.00 per ton, and prices were even higher in 1919 and 1920. After 1920, the domestic production fell from the 1918 level to about 125,000 tons annually and the average price dropped back to about $18.00 per ton. By 1935 the average price had fallen to $15.00, but in 1940 with a rising demand the average price of all grades had gone back up to $20.31. Today it is 75 per cent higher than in 1940 and presumably the price of acid grade at .least would be even higher if it were not for price ceilings. The first subsequent year that the domestic production exceeded that of 1918 was 1941, and the 1944 production is expected to exceed 400,000 tons, or over one and a half times that of 1918. In five-year periods, average production and imports were as are shown in Table I. Many people concerned with the consumption of fluorspar believe that the postwar period ahead will show a repetition of price trends of the last such period. They believe that imports will be again an important factor in the available supply and the price will fall back gradually toward the prewar level. The following basic factors are pertinent in analyzing this conclusion:

Jan 1, 1948

By Oswald J. Heinrich

The serious objections to the Leblanc soda process may be enumerated as follows: 1st. The total loss of sulphur employed, equal to about one-third of soda produced. Various processes have been proposed to regain this sulphur, but none have come into practical operation on a large scale. 2d. The great balk of waste products, equal to nearly twice the amount of soda, which forms a serious annoyance about the works. 3d. The complicated series of operations necessary. 4th. The large amount of labor and fuel required. 5th. The prodoction of noxious gases which necessitate extensive condensing arrangements. 6th. The large capital necessary for the . erection and maintenance of the plant, These objections have long been recognized, and many attempts have been made during the last thirty or forty years, to discover and introduce a cheaper and more direct method for the manufacture of this important staple. The reaction between bicarbonate of ammonia and common salt, whereby bicarbonate of soda, insoluble in a solution of chloride of ammonium, is precipitated, has been closely studied for the last twentyfour years, on account of its simplicity and the purity of the product it affords. This ammonia-soda process is now so far developed, that while it is not in position to entirely replace the Leblanc process, yet it can successfully compete with it where the conditions and localities are favorable. The advantages of the ammonia-soda process may be summed up as follows : 1st. It is independent of the essential agent in the Leblanc process, via., sulphuric acid, and hence can be established in those localities where salt is abundant, and yet where sulphuric acid could not be made, or where it could not be transported profitably. 2d. The ammonia-soda process being a " wet" process, the evaporation of salt brines to obtain the solid salt required in the Leblanc process, is rendered unnecessary. 3d. The direct conversion of chloride of sodium into bicarbonate of soda, which can readily be converted into the maketable monocar-

Jan 1, 1879

By Paul Billingsley, Augustus Locke

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

By Paul Billingsley, Augustus Locke

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

By Augustus Locke, Paul Billingsley

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

By H. R. Stahl

The disseminated lead district of Southeast Missouri lies 70 miles south of St. Louis. The only metal of economic importance in the ore is lead, but minor amounts occur of iron, zinc, copper, cobalt, nickel, silver and cadmium. These minor metals, as might be expected, tend to concentrate in both the flotation and table middlings. In the past, some zinc has been recovered by differential flotation. The silver and cadmium tend to associate with the zinc, and some recovery is made of these two metals at the smelter. The lead occurs as galena, or lead sulphide. The minor metals are also present as sulphides. The presence of oxidized lead is suspected, but has not been definitely proved. The gangue is chiefly dolomitic limestone, with small amounts of sandstone and shaly glauconitic and chloritic minerals. The ore contains about 3.25 per cent lead, occurring as galena disseminated through the gangue. Some of the galena is very finely disseminated, and the mineral in the gravity tailings, or chat; is seldom or never in the free state. The method of treatment of the ore has been evolved over a period of 75 years; hence probably is not far from correct. The milling processes have tended toward simplification during the past 15 years, but recoveries have never been sacrificed for the sake of simplicity. In many cases, simplification of flowsheets has led to better recoveries and operating economies. A simplified flowsheet is shown in Fig. I. The St. Joseph Lead Co. operates four mills in the Flat River district, with a normal total capacity of about 21,000 tons per day, divided as follows: Federal mill, 11,000 tons; Leadwood mill, 4500 tons; Desloge mill, 3400 tons and Bonne Terre mill 2400 tons. The methods of concentration used at these plants are similar in principle; they differ mainly in details and in the type and size of the equipment used. The process of concentration may be divided into five main steps; i.e., dry crushing, wet grinding, classification with its attendant desliming, tabling and flotation. A brief description of these processes will be given, noting important differences in the various plants, and also noting the more important changes or developments of the past few years. Dry Crushing The run-of-mine ore is hoisted in skips, the capacity of these skips ranging from 23/4 tons to 81/4 tons. At the Desloge plant, the ore is hoisted in 2-ton mine cars on self-dumping cages. All ore is hoisted at shafts adjacent to the various crushing plants, no ore being transported on the surface. Primary breaking at all the mills is accomplished with 9E Telsmith breakers. Preliminary screening is provided ahead of most of these crushers, either by station-

Jan 1, 1943

By H. R. Stahl

The disseminated lead district of Southeast Missouri lies 70 miles south of St. Louis. The only metal of economic importance in the ore is lead, but minor amounts occur of iron, zinc, copper, cobalt, nickel, silver and cadmium. These minor metals, as might be expected, tend to concentrate in both the flotation and table middlings. In the past, some zinc has been recovered by differential flotation. The silver and cadmium tend to associate with the zinc, and some recovery is made of these two metals at the smelter. The lead occurs as galena, or lead sulphide. The minor metals are also present as sulphides. The presence of oxidized lead is suspected, but has not been definitely proved. The gangue is chiefly dolomitic limestone, with small amounts of sandstone and shaly glauconitic and chloritic minerals. The ore contains about 3.25 per cent lead, occurring as galena disseminated through the gangue. Some of the galena is very finely disseminated, and the mineral in the gravity tailings, or chat; is seldom or never in the free state. The method of treatment of the ore has been evolved over a period of 75 years; hence probably is not far from correct. The milling processes have tended toward simplification during the past 15 years, but recoveries have never been sacrificed for the sake of simplicity. In many cases, simplification of flowsheets has led to better recoveries and operating economies. A simplified flowsheet is shown in Fig. I. The St. Joseph Lead Co. operates four mills in the Flat River district, with a normal total capacity of about 21,000 tons per day, divided as follows: Federal mill, 11,000 tons; Leadwood mill, 4500 tons; Desloge mill, 3400 tons and Bonne Terre mill 2400 tons. The methods of concentration used at these plants are similar in principle; they differ mainly in details and in the type and size of the equipment used. The process of concentration may be divided into five main steps; i.e., dry crushing, wet grinding, classification with its attendant desliming, tabling and flotation. A brief description of these processes will be given, noting important differences in the various plants, and also noting the more important changes or developments of the past few years. Dry Crushing The run-of-mine ore is hoisted in skips, the capacity of these skips ranging from 23/4 tons to 81/4 tons. At the Desloge plant, the ore is hoisted in 2-ton mine cars on self-dumping cages. All ore is hoisted at shafts adjacent to the various crushing plants, no ore being transported on the surface. Primary breaking at all the mills is accomplished with 9E Telsmith breakers. Preliminary screening is provided ahead of most of these crushers, either by station-

Jan 1, 1943

By John A. Wolfe

The brightest spot in the mineral economy of the Philippines is the rapid development of reserves and production of copper. If economic conditions remain favorable and the political climate is encouraging, production of this metal should increase at a rate of 25% per year for several years, long enough to rank this country as one of the major copper producers of the world. In 1965 the copper content of the Philippine concentrates was approximately 60,000 tons. It should total about 80,000 tons in 1966. A major part of the increase will come from the rich Lepanto mine located in Mountain Province, North Central Luzon. Daily production of ore increased from 1200 to 2000 tons at the end of 1965. The ore, consisting of enargite and luzonite, averages nearly 3% copper and 0.12 oz. of gold per ton. It is an under- ground operation with a cutoff grade of 2%. The ore is associated with extensive silicification under a volcanic cap rock. Further expansion to increase ore production to 2600 tpd is under way.

Jan 4, 1967

By R. J. Evans

The Combined Metals Reduction Co.'s plant is at Bauer, Utah. It was built primarily to treat ore from the Combined Metals mine at Pioche, Nevada. Shortly after its completion, the company acquired the old Honerine mine, and ores from this mine, as well as custom ores from widely scattered districts, are now being treated at the Bauer plant. Pioche Ore The Pioche ore, which comprises about 50 per cent. of the mill feed, occurs as a replacement of an impure thin-bedded limestone. The lime beddings are separated by thin layers of micaceous shale containing appreciable quantities of sericitc and graphite. The ore is an exeeptionally fine-grained, dense mixture of minerals and gangue, assaying approximately 0.03 oz. gold, 7.2 oz. silver, 7 per cent. lead, 15 per cent. zinc, 16 per cent. iron, 29 per cent. insoluble and 1.5 per cent,. lime. Of the total lead 7 per cent. is in the form of sulfate and carbonate. Approximately 10 per cent,. of the ore consists of chert nodules impregnated with barren pyrite; the nodules average 0.8 mm. in size, and ire extrcmely hard, compared with the other constituents of the ore. Microscopic examination of Pioche ore ground to 80 per cent . minus 150 nicsh shows pyrite, sphalerite and galena still attached. Early Attempts at Ore Dressing Metallurgists, both professional and those working for private companies, have been more or less familiar with the Pioche ore sinee. 1913; in fact, a total of 35 commercial and plant laboratories expenmented with the ore between 1913 and 1921. The work during this period was decidedly negative, it being seemingly impossible to effeet a satisfactory separation of the valuable minerals into marketable products. In 1913, it was recognized that fine grinding-—that is, about minus. : 200 mesh—-was required to liberate the minerals from one another, and from the gangue, but such fine grinding was not considertd practicable at this time.

Jan 1, 1928

By Nicholas J. Grant, A. W. Mullendore

Measurements of grain boundary sliding were made on polycrystal and bicrystal tensile creep specimens of Al-2 pct Mg at 500oand 700oF. Grain and pain boundary orientation factors were studied with respect to their effect on the magnitude and direction of grain boundary sliding. It was concluded that a large part of the observed sliding may be caused by the operation of slip crossing the grain boundaries. Supporting evidence for this model from other investigations is also given. GRAIN boundary sliding in metals during elevated temperature deformation has frequently been thought of as an independent mechanism with its own characteristic stress, temperature, and structure dependence. Further, it is common to regard the grain boundary as the weak link during creep deformation since: 1) the strength of apolycrystallinemetal, as meas-sured by creep rate or rupture life, decreases at\a more rapid rate when sliding comes into action, and 2) grain boundary sliding, as revealed by "boundary darkening" and fold formation is often the first visible deformation. On the other hand, more quantitative observations, in both polycrystals and bicrystals, have shown boundary deformation to be closely related to the over-all deformation of the specimen. The curve of grain boundary contribution to elongation vs time takes a shape similar to that of the total creep curve,',' and the apparent activation energy for sliding appears in most cases to have the same value as that for total creep.3 In order to reconcile these observations, one is left with these possibilities: 1) The grain boundary and grain deformation rates are both controlled by the same rate limiting processes. 2) The rate of sliding is limited by accommodation deformation in the grains. 3) Sliding is the consequence of grain deformation. 4) Grain deformation is dependent on prior grain boundary deformation. Alternatives 2) and 3) would view grain boundary sliding as occurring in series with another deformation process which could be rate controlling. McLean prefers item 3) as the sliding basis,4 where subgrain rotation results from dislocation accumulation in the substructure at the grain boundary. Crussard and Friedel's5 treatment of grain boundary migration considers that dislocations are forced into the grain boundary and are dissociated into dislocations with Burgers' vectors nearly parallel to the grain boundary. The movement of these partial grain boundary dislocations then produces the sliding. The results of this investigation have indicated alternative 3) to be the most appropriate and it is this aspect of grain boundary sliding which will be analyzed. EXPERIMENTAL PROCEDURE Three types of tensile creep tests were employed in this study: (I) A constant load test of one very coarsegrained polycrystalline specimen at 500° F, 3600 psi, 1 pct per/hr strain rate to examine the grain and grain boundary orientation factors in grain boundary sliding. (II) Constant strain rate tests of polycrystalline specimens at 510o and 715o F, 2 pct per/hr strain rate to determine the grain boundary contribution to elongation at very low total strains. (m) Constant strain rate tests of bicrystals of various grain and grain boundary orientations at 500°F, 2 pct per/hr strain rate to obtain further information on the orientation effects in grain boundary sliding. The material used in the tests was a high-purity Al-1'.92 mg alloy, kindly furnished by Alcoa. Its composition is given in Table I. The alloy is a solid solution at the test temperatures. The coarse grained polycrystalline specimen for test (I) was prepared by recrystallizingthe machined specimen, straining it about 1pct intension at room temperature and annealing at 900°F for 8hr. The constant strain rate specimens (11), with an 178 in. sq. by 1/2 in. long gage section, were cut from 1/8 in. thick sheet of cold rolled and annealed (8 hr at 1000oF) material. The latter specimens were supported in a special jig during the milling operations to avoid any bending, and the gage section was subsequently heavily electropolished to remove the cold-worked surface layer. The bicrystals (ID) were machined in the same

Jan 1, 1963

By Albert Zima

ACCORDING to recently published statistics, it is predicted that as much oil must be produced during the next 16 years as has been produced during the past 75, in order to satisfy the high rate of consumption of petroleum products. During 1934, over 17,000 oil wells were completed in the United States, and it is expected that over 20,000 additional wells will be drilled during the current year. Were it not for the remarkable progress made during recent years in the improvement of drilling technique and in the development of equipment used in the production phase of the oil industry, it is doubtful whether sufficient oil could be produced to meet present requirements. A few years ago, wells seldom were deeper than 3500 to 4000 ft., owing to the limitations of the drilling methods and equipment employed. Today, however, through the application of scientific drilling methods and the adaptation of modern equipment and improved materials, many wells range from 6000 to 8000 ft, in depth, and a few recent completions exceed 10,000 feet.

Jan 1, 1935

By H. Margolin, E. Ence

In order to understand the effect of zirconium on properties of Ti-Cu-A1 alloys, Ti-Zr alloys were examined for the presence of ordering or compounds at the following compositions in weight percent: 24.1 pct Zr (lZr:GTi), 32.2 pct Zr (lZr:4Ti), 38.8 pct Zr (lZr:3Ti), 49.0 pct Zr(1Zr:ZTi). Alloys were prepared as 15-g buttons by non- consumable arc melting under argon atmosphere from Bureau of Mines titanium (Bhn 63) and Reactor Grade zirconium (Bhn 150). Weight losses during melting did not exceed 1 pct of the initial button weight. Prior to heat treatment, buttons were hot-rolled at 600" to 700°C to rods of about 6 mm diam. Contamination after hot-rolling was found to extend to a depth of less than 0.5 mm. Specimens for heat treatment were wrapped in molybdenum sheet, annealed in argon-filled quartz capsules, and quenched by breaking the capsules under iced brine. Annealing times were as follows: 700°C — 7 days; 600°C— 14 days; 575°C-1 and 2 months; 525°C-2 months; 500°C-2 months. Prior to heat treatment, all Ti-Zr alloys were vacuum annealed at 900°C to remove hydrogen. The reanneal of 575°C specimens for an additional month produced no observable microstructure changes. The results obtained by microstructure and X-ray diffraction are shown in Fig. 1, together with data of Hayes et al.' No other phases than a or P were found. Small amounts of retained P were detected by X-ray in the 49 pct Zr alloy. The data of the present investigation suggests that ß and a transus boundaries are at considerably lower temperatures than those of Hayes et al. The work of Hayes et al. is based on sponge titanium and Bureau of Mines zirconium, both of which contained 0.15 pct 0. Since melting was performed in

Jan 1, 1962

By Z. M. Zavodni

The stability of waste dumps depends to a great extent on the physical properties of the underlying foundation. These physical properties are evaluated through surface geotechnical surveys, subsurface exploration, and field and laboratory testing. Sufficient information must be obtained to define and assess the strength, consolidation, distribution, topographic and hydrogeologic properties for these materials. Important foundation data collected in the field include: surface infiltration rates, downhole hydraulic conductivities, ground water levels, bedrock structural parameters, soil types and soil thickness. Laboratory testing should identify the classification, strength, moisture content, hydraulic conductivity, attenuation and consolidation characteristics. Summarized in this paper are procedures and typical results of porphyry copper leach dump foundation investigations. Laboratory properties and design recommendations for potenia1 foundation liner materials are described. Back analysis and laboratory foundation strengths are compared. The topographic effect of the foundation on dump behavior is discussed and a foundation pore pressure monitoring experiment at the toe of an active waste dump is described.

Jan 1, 1985

By C. W. Nicolson

THE Tri-State zinc and lead-mining district is in the northeast corner of Oklahoma, the southeast corner of Kansas and the southwest corner of Missouri. The area throughout which active mining has been conducted is about 45 miles long and about 5 miles wide, extending northeasterly from Commerce, Okla., to Alba, Missouri. Although the lead ores were mined on a very small scale in the vicinity of Joplin, Mo., as early as 1848, nothing of any importance was done in the district until 1870, since when both mining and smelting have been prosecuted with considerable vigor. In the beginning the lead ores only were exploited, but within a few years extensive deposits of zinc ores were found and since that time the production of zinc ore has far exceeded that of lead. Both the surface and mineral rights in Missouri and Kansas were under individual ownership by the time ore was discovered. Although some of these rights were purchased by mining companies, most of the mining has been done under leases covering small areas, usually 40 acres, although in the past many leases were given on much smaller tracts. In Oklahoma most of the mineral land had been alloted by the Government to various Indian tribes and although the title to some of these lands had been acquired by various white men before the discovery of the rich Picher field, the title to most of the land has remained with the Indian tribes and the leasing of the mineral rights has been done by the Federal Government for the benefit of the Indians. The Indian allotments were of 200 acres each and some of the mining leases covered entire allotments, although many leases were granted for only 40 acres or even less. Practically all of the leases granted in the past required the erection of a concentrating plant on each lease, a condition that has had a pronounced effect upon the mining and milling methods of the district, since the apparent ore reserves on each tract were too small to justify large

Jan 1, 1938