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By William R. Rumbold

When I was in South Africa during the latter part of 1904, there were three known tin-fields, which may be called the Cape Town, the Bushveld, and the Swaziland fields. The Cape Town Tin-Field. This district is situated near Kuils river, 20 miles west of Cape Town, and 5 miles from Kuils River station on the Cape Town & Stellenbosch railway. The deposits are in granite, intrusive in the Malmesbury beds, which are supposed to be of Silurian or Cambrian age. The granite, resisting denudation better than the surrounding shales, has formed low-lying hills, the highest of which, the Bottlelary Berg, is 1,510 ft. above sea-level. The rock consists of quartz, orthoclase feldspar, and biotite mica; tourmaline is also present. The feldspar occurs in large crystals. The rock is generally decomposed on the surface, and the decomposition sometimes extends as deep as 100 ft. This formation—granite intrusive in Silurian shales— extends for many miles to the northeast, but so far as I know the Kuils River deposits are the only ones now known to occur in it, though probably further prospecting will reveal other deposits. This particular discovery was accidental; alluvial tin being found in the course of boring for oil. The Kuils River Deposit. This deposit comprises both lode and alluvial tin. The lode strikes N-S., and dips about 30' E. into the hill. It is 5 ft. wide, and composed of dense white quartz, in which pinkish-gray cassiterite is distributed in large crystals. The vein also contains considerable quantities of wolframite. Fig. 1 is a rough plan of the relative positions of the lode and the alluvial deposit, the latter, as shown, following the course of a stream, while the lode crops out on the hillside ,

Jan 1, 1909

By Thomas V. Falkie

4.3-1. Introduction. DEFINITION OF PRODUCTION SYSTEMS ENGINEERING. Surface mines, like most other mining and manufacturing operations, are usually organized along functional departmental lines. Frequently a mine manager will have his responsibilities divided among production, maintenance, administrative, and engineering functions. Often these are separate departments, but various combinations and variations of these functions can be found in mining companies throughout the world. The production function is responsible for physically removing the ore from the ground, processing it, and shipping the product to its market. The production manager supervises and is responsible for all man-machine systems necessary to extract and process the ore. The maintenance function, which is sometimes included within the framework of production, has the task of insuring the maximum availability and longevity of equipment needed to produce the ore. The administrative function is responsible for accounting, personnel, industrial relations, purchasing, public relations, property, and other related staff functions. For purposes of this chapter, engineering can be described as the function which plans, designs, and supervises construction of physical plant and equipment. In this context engineering includes mechanical, civil, chemical, electrical, and mining engineering. However, another phase of engineering is to prepare plans to insure that the various man-machine components function in an optimum way towards the single most important goal of any enterprise-the maximization of return on the investors' money. Along with the planning, another duty of engineering is to audit all phases of the operation for the purpose of recommending improvements toward this same general goal. These latter two ideas form the basis for a discussion of production engineering and systems engineering. Production engineering is a catchall, problem-oriented function whose duties can include: 1) solution of day-to-day production problems, 2) short-

Jan 1, 1968

By H. M. Howe, E. C. Groesbeck

That the quiescence of a liquid while it is solidifying should favor the formation of columnar crystals, normal of the cooling surface, is seen readily on considering the mechanism of solidification. First, each particle of any composite liquid, whether it be an aqueous solution or a molten metal, in solidifying splits up into two parts, different in composition and hence in fusibility. One part is infusible at the existing temperature, and hence solidifies, and in general attaches itself to the inclosing walls of metal which have already solidified; A, Fig. 1. The other part is fusible at the existing temperature and hence remains molten. In the case of carbon steel, the part of each drop which actually solidifies is poorer in carbon than the drop itself was before it began to solidify, and this impoverishment of the solidifying half-drop enriches the other half-drop in carbon, and thus makes it unfreezable at the existing tern- By this mechanism there arises during solidification a "littoral" or shore layer of liquid B, Fig. 1, bathing the already solidified walls, and more fusible than either those walls or the great remaining central mass of liquid or " deep sea " C, from which it separates them. It is essential that we grasp clearly this conception of a fusible littoral molten layer coating the already solidified walls and separating them from the deep sea. Meanwhile heat is flowing rapidly outward through these walls, its escape cooling them, so that if any given particle of the deep sea metal could get past this littoral layer and come into contact with the solid walls, it would in turn solidify, and like its predecessors would split up in solidifying into a less fusible half-drop which would attach itself to those . walls and a more fusible one which would remain molten. Thus we see

Jan 1, 1920

By N. S. Stoloff, K. R. Jordan

The temperatwe and grain size dependence of the mechanical avoperties of ordered and disordered Fe-49 pct Co-2 Pct V were investigated. The yield and flow stresses obeyed the Hall-Petch relationship u = ai + kd-&apos;I2. Ohdering reduced the intercept stress cjj and raised the Petch slope, k, at all temperatures. Ordering also increased the temperatwe dependence of k. The ductile to brittle transition temperature increased with order and grair~ size. Cleavage fracture was nucleation limited and the fracture stress did not zlary linearly with d-&apos;". A quantitative test of the Cottrell-Petch fracture theory (and recent modifications which consider the influence of slip mode), demonstvated that this theory is not applicable to FeCo-V. COTTRELL&apos; and etch&apos; independently suggested that a criterion for cleavage failure at the yield point, a,, based on dislocation pileups at a grain boundary or other obstacle to dislocat.ion motion, is: aYYkd&apos;I2 1 opy [ll or, equivalently, aikz,d112 +k:)bpy [2] where a, and ky are the Hall-Petch intercept and slope, respectively, 2d is the grain diameter, P is a geometric factor dependent on the macroscopic ratio between shear and tensile stress, p is the shear modulus, and y is the true elastic surface energy. When the product of quantities on the left side of the equation is equal to or exceeds that on the right, cracks should be able to nucleate and propagate at the yield stress, as shown schematically in Fig. 1. Therefore a high intercept stress, high Petch slope, or coarse grain size favors brittleness. petch3 associated the existence of a ductile to brittle transition in ferrous alloys with the temperature dependence of ai. One of the earliest modifications of the Cottrell-Petch theory was presented by ~rmstrong,~ who derived an expression for transition temperature in terms of several measurable flow and fracture parameters. The latter paper was able to rationalize situations in which the transition temperature increases with decl-easing grain size, as in the case of molybdenum,&apos; and also suggested that Ppy should be a function of grain size as well as temperature. More recently Johnston et a1.6 and Smith and worthington7 have suggested that the temperature or composition dependence ol&apos; ky must also be taken into account if there is any cha.nge in deformation mode, as from wavy to planar slip, or wavy slip to twinning, with change in temperature or solute content. Armstrong %as suggested that for hcp metals changes in o;k,dw> o;k,d1/2< / is / ^^^^ / / y_______________________________________ d-"2 Fig. l—Schematic representation of grain size dependence of yield stress, cry, and fracture stress, CTF. Intersection defined by Cottrell-Petch equation. slip mode should be incorporated in the theory through changes in the critical resolved shear stress for the slip system which controls ky. The purpose of the present investigation was to critically test the modified677 Cottrell-Petch theory of fracture in the superlattice alloy Fe-49 pct Co-2 pct V, by studying the grain size dependence of the yield and fracture stresses over a range of temperatures, in conjunction with an investigation of slip mode and fracture behavior. Previous work has shown that long range order results in a sharp decrease in flow stress, a small increase in work hardening rate and a drastic upward shift in the ductile-brittle transition temperature of F~CO-V.~&apos;~ The only comprehensive study of slip character in this alloy has been reported in a preliminary account of the present investigation.10 EXPERIMENTAL PROCEDURE The experimental work was carried out on material produced from a 10 lb vacuum melted ingot, of composition 49.32 wt pct Co, 2.09 wt pct V, balance Fe. 30-mil thick sheet samples with a 1; in. gage section were machined from cold rolled stock. The degree of cold work ranged from 85 pct for the finest grained samples to 5 pct for the coarsest grain size. Details of ingot fabrication are reported elsewhere." Equi-axed grain sizes in the range 12.7 to 75.4 p were obtained by annealing for varying times at 850°C. (Re-crystallization annealing time, rather than temperature , was varied to control grain size to insure that samples of all grain sizes contained equivalent quenched-in vacancy and interstitial concentrations.) Grain sizes were measured by the line intercept method on several specimens of each grain size. Following recrystallization, all samples were disordered by quenching into iced brine.

Jan 1, 1970

"In 1899 the American Refining and Smelting Company obtained control of the East Helena Smelter, and have added improvements from time to time.The plant is four miles east of Helena, on the Northern Pacific and Great Northern railroads, with hourly street car service from Helena.Electric power is obtained from Canyon Ferry dam, twelve miles east on the Missouri river, and about 800 h-p. is used in the blowing engines, crushing machinery, cranes and locomotives.Besides the Montana ores convenient to the above railroads, a large part of the ore supply comes from the Coeur d'Alene district, Idaho, and is mainly lead ore and concentrates.A modern automatic sampling mill, with Vezin samplers and a capacity of 50 tons per hour, was completed in 1912.Three blast furnaces, each 48 inches by 136 inches, are now in continuous operation, and the monthly production of silver-lead bullion is six thousand tons.A part of the ore roasting is done in Godfrey furnaces, in connection with the Huntington-Heberlein process, 12 pots being in use, with a capacity of 300 tons per day.Four Dwight-Lloyd sintering furnaces, each 42 inches by 264 inches, and a smaller experimental machine, with a combined capacity of 440 tons per day, are in steady operation, and are successfully roasting ore as well as sintering flue dust. These machines are in great favor and results are being carefully watched.Three bag houses are used in connection with the 1,800 brick flue chamber, and each bag house contains 1,260 cotton bags, each 18 inches in diameter by 30 feet long, suspended on vertical roads. The product saved by the bags contains about 50 per cent lead and is retreated in the blast furnace after sintering.About 450 men are employed."

Jan 1, 1913

By E. T. Turkdogan, Klaus Schwerdtfeger

OelSEN and Maetz1 detected some 20 years ago the existence of a miscibility gap in iron oxide-CaO-P2O5 slags melted in iron crucibles at about 1400°C. Because of the importance of this system for the dephos-phorization of steel in the basic Bessemer process, equilibria between liquid iron and selected iron oxide-CaO-P2Q slags have been measured since by numerous investigators.2-5 When in equilibrium with metallic iron, the iron oxide of the slag is present mainly as FeO. In connection with oxygen-blowing steelmaking processes, it is useful to know the phase relations in the slag system at higher oxygen pressure, when major parts of the iron oxide are present as Fe2O3. This problem was investigated by Turkdogan and Bills7 by equilibrating the oxide mixtures contained in platinum crucibles with CO2-CO mixtures at 1550°C. It was found that increasing the Fe2O3 content decreases the composition range of the miscibility gap strongly so that the miscibility gap has almost disappeared at pco2/pco = 75. This result was refuted by the careful work of Olette et a1.,&apos;&apos;&apos; who equilibrated their slags with controlled Ha-H2-Ar gas mixtures. Their equilibrium measurements, at 1600°C and at oxygen pressures of 5 x 10"* and 10"5 atm, showed that the oxidation state of the iron has almost no influence on the formation of the miscibility gap. The present experiments were undertaken to check the previous results of Turkdogan and Bills. The experiments were performed at 1625°C in the strongly oxidizing atmosphere of air (PO2 = 0.20 atm) for which no experimental data are available. About 10 g of slag were melted in platinum crucibles and held at constant temperature for 1 hr. After equilibration, the crucible was rapidly pulled out of the furnace and cooled in air. The platinum crucible was removed from the sample. The two slag layers were carefully separated with a small diamond disc, and the surface of the top layer, which may have changed its oxidation state during cooling, was removed. The slags were crushed and analyzed chemically for CaO, P2O5, Fe2+, and Fetotal. The starting mixtures were prepared by sintering the desired amounts of reagent-grade 2CaO . P2O5 - H2O, CaCO3, and Fe2O3. Sintering and subsequent crushing were done three times to ensure homogenization. Molybdenum wire resistance heating was used. The furnace was provided with a recrystallized alumina reaction tube which was left open to air at the top. The temperature was controlled electronically. The reported temperature was measured with a Pt/Pt-10 pct Rh thermocouple and is estimated to be accurate within +5°C. The composition of the equilibrated melts is given in Table I. For the graphical illustration of these quaternary slags the type of projection suggested by Trömel and Fritze10 was used. In this representation, Fig. 1, the composition point of a mixture within the tetrahedron Fe2O3-CaO-P2O5-FeO is projected into the Fe2O3-CaO-P2O5, triangle (triangle I) so that the direction of projection is parallel to the side FeO-Fe2O3, and into the triangle Fe2O3-P2O,-Fe0 (triangle 11) so that the direction of projection is parallel to the side CaO-P2O5, of the tetrahedron. The projected point has the coordinates wt pct CaO, wt pct P205, and wt pct (FeO + Fe2O3) in triangle I and wt pct FeO, wt pct Fe2O3, and wt pct (CaO + PzO5) in triangle 11. Both triangles are turned into the same plane around the Fe203-P20, side of the tetrahedron. An illustration of the projection of a quaternary point in the present system is shown in Fig. 1. The advantage of this type of projection is that all four components for an equilibrium curve can be read directly from the diagram. The present results are shown graphically in Fig. 2. The curves depicting the miscibility gap are dashed in parts where no experimental points were obtained. The composition range covered by the miscibility gap

Jan 1, 1968

By Charles Frey

TIE fundamental principle of resistance thermometry lies in the determination of temperatures by the measurement of an electrical conductor subjected to various temperatures and the translation of the resultant changes, in ohms, into temperature equivalents. Such resistance measurements can be made with maximum precision by the use of a standard Wheatstone bridge and a reflecting galvanometer of high sensitivity. Under such conditions, results are obtainable that may be accurate within 0.1 or even 0.01 per cent., and the "idiosyncrasies" of heated electrical conductors can be studied with advantage and profit, even if the latter is not of a financial nature. The chief requisites for producing a serviceable -commercial instrument may be enumerated as follows: First, there must be a resistor or "bulb" that can stand the maximum temperature without deterioration and which has a pronounced temperature coefficient. Second, there should be constructed an "even" bridge, having two fixed arms of equal values, in ohms. Third, a rheostat, the maximum resistance of which will be equal to the total change in the resistance of the bulb, between temperature extremes, is required. Fourth, there must be a sensitive galvanometer which is aperiodic, or nearly so. Finally, there should be a fairly steady source of direct current. The general scheme of this type of apparatus, in its simplest form, can be readily understood by reference to Fig. 1. Resistors A and B are constructed of manganin, therlo, or some other resistance wire having a negligible temperature coefficient. The sensitive D&apos;Arsonval galvanometer G has its zero in the center. R is a rheostat and X is a resistor or bulb made of insulated platinum wire, or else of nickel, copper, or some alloy, according to requirements. K is a battery, but a direct-current service line is often used instead, with sufficient ballast in series to properly reduce the current.

Jan 8, 1919

By Donald C. Moore

INTRODUCTION Published laboratory procedures used by the major crusher manufacturers for estimating crusher size are based upon techniques developed in the mid 1940&apos;s. Specifically, the two largest U.S. crusher manufacturers are using the Bond impact procedure. Although the procedure is still in use, there is little confidence in the results. Unless the laboratory results fall within a preconceived range, personal experience is used for selecting the number of crushers and connected horsepower (Coleman, 1978). There have been numerous theoretical studies of the communition of particles. However, no procedure has been widely acclaimed for predicting crusher power requirements. Experimental studies have included breakage by slow compression, slow speed impact and high speed impact. Theoretical results have increased our knowledge of the comminution process, but the procedures have not been capable of analyzing the complex mechanism of industrial crushing machines. The purpose of this chapter is to review the empirical crushing procedures that have been used, including advantages and disadvantages. A new procedure which has been in development at Allis-Chalmers Corp. from 1977 to 1982 is detailed. Actual results of the new procedure on a concentrator feasibility study are included. EXPERIMENTAL GOALS The goals of a laboratory crushability procedure are accurate predictions of: (1) Rock crushability, measured as energy per unit mass. (2) Crusher product size analysis. A procedure capable of predicting these parameters should be inexpensive and require a minimum amount of sample. CRUSHABILITY TESTS Bond Impact Procedure F. C. Bond (1946) detailed the development of the pendulum impact device that is still used by the leading crusher manufacturers (Bond; Rexnord, 1976). The device (Fig. 1) is comprised of two bicycle wheels with 13.6 kg steel hammers tangentially attached to the rims. The hammer faces are 50 mm apart at rest. On opposite ends of the hammers lifting

Jan 1, 1982

By T. H. Alden, H. W. Schadler

The strain rate dependence of the flow stress of the eutectoid Zn-Al alloy has been determined as a function of mechanical processing, microstructure, and temperature. The best superplastic properties result from the ultrafine, equiaxed structure produced by solution treatment and isothermal transformation at 0°C. Lamellar structures produced by isothermal transformation and coarse equiaxed structures produced by annealing also exhibit strain rate sensitivity in excess of 0.5, but at higher stresses and lower strain rates than the finest structure. Solution treatment and isothermal transformation eliminate the effect of prior processing history. Small composition variations in the binary alloy do not influence the mechanical properties. Below the eutectoid transformation temperature (.275C) increasing temperature lowers the flow stress at all strain rates. The data do not favor any of the present proposals for the mechanism of superplastic flow. ALLOYS of zinc and aluminum, near the eutectoid composition, have been investigated for: 1) the flow stress-strain rate and elongation behavior,1, 2) the transformation kinetics,3 and 3) structure,3"5 but the structure sensitivity of the mechanical properties is poorly understood. Using a near eutectoid alloy water-quenched from 380°C, Backofen et aL2 estab- high and increases with increasing strain rate. They found a correlation between strain rate sensitivity and tensile elongation as expected from the increased resistance to necking that a high strain rate sensitivity provides.296 The large elongation at high strain rates is attractive for metal forming. Since most other superplastic alloys7-l3 do not show high strain rate sensitivity at such a high strain rate (for the exception see Ref. 12) there is the possibility of a unique deformation mechanism for this alloy. The sensitivity of the mechanical properties of the eutectoid alloy to thermal history1 suggests a structure sensitivity that has not been demonstrated. Gar-wood and Hopkins3 identified a lamellar product for material transformed between 200" and 260°C. The size of the lamellae decreased with decreasing temperature. They also demonstrated that an unresolved transformation product formed below 200°C. A granular two-phase material was resolved for specimens quenched to below 150°C by Mitbauer and sauerwald4 who observed coarsening of the structure after annealing. The role of grain boundaries in superplastic deformation is suggested by the strong effect of grain refinement in encouraging this phenomenon at high strain rateS7-11, 13 and is emphasized in several proposals about rnechanism7, 8, 12 and in a theory14 of high-temperature deformation. Alden8 showed metallographic evidence that grain boundary sliding is occurring extensively at strain rates where m is large but less at high strain rates where normal plasticity is observed. Holt and Backofen10 have shown that sliding also oc-

Jan 1, 1969

By S. Isserow

RECENTLY, a description of the wartime work in this laboratory on the U-Si phase diagram was published. This diagram was available earlier in the open literature; as were Zachariasen&apos;s crystal structure identifications for the compounds in the system. The uranium end of the phase diagram is shown in Fig. 1. The most recent work on this system has emphasized the peritectoid E phase, of particular interest for a number of reasons. The early work provided evidence of this phase&apos;s resistance to corrosion in water and of its slight ductility. Further information on these properties has been obtained here. Work elsewhere4 has provided evidence of stability under irradiation. This body-centered-tetragonal phase is relatively isotropic compared to the more usually applied a or ? uranium phases. Unlike the other compounds in this system, it contains no Si-Si covalent bonds.3 In addition, consideration on the basis of Pauling&apos;s concepts leads to the conclusion that in the E phase, uranium has a higher valence than in any of the other phases. Definition of the composition of the ? phase has been of prime concern in the study of this alloy. Evidence is presented below that its silicon content is slightly higher than that of stoichiometric U8Si, the composition frequently assigned this phase on the basis of Zachariasen&apos;s identification. This work on the composition required careful attention to the method of dissolving the alloy for analysis, since apparently low silicon contents could be found under certain conditions, see Appendix. Preparation: Melting, Casting, and Heat Treatment—Almost all the samples were from castings with a diameter of 13/4 or 2 in. and about 1 ft long, weighing 10 to 15 lb. The U-Si charge was melted by heating to about 1650°C in an induction heated vacuum furnace. Beryllia crucibles were used at first, but were replaced by zirconia-washed graphite as the technique of keeping the carbon content low enough (about 500 ppm) was mastered. The alloy was bottom-poured at about 1650°C into graphite molds. A few small buttons, weighing no more than 50 g, were prepared in a small arc melting unit.&apos; Since cast material has a preponderance of uranium and U8Si2, heat treatment is necessary to ob-tain the ? phase by the solid-solid peritectoid reaetion. Once obtained, the ? phase is stable to room temperature, obviating the need for speeial attention to the method of cooling after epsilonization, see Fig. 1. It was found desirable to epsilonize at 800°C for a week. For some purposes, in which residual uranium and/or U8Si2 are tolerable, shorter periods may be adequate. The temperature of 800°C is not critical, since essentially the same results were obtained from 785° to 825°C. Further departure from this epsilonization range is inadvisable.

Jan 1, 1958

By D. C. McLean, S. A. McKay

The purpose of this paper is threefold: 1) to describe actual ground control installations made at the various mines of the International Nickel Co. (Canada) Ltd mines in Sudbury, Ont. during a planned test program. 2) to suggest new ground control techniques which are now possible by the use of fully grouted bolts 3) to indicate the possible economic advantages to be gained by the use of resins and resin grouted bolts to control difficult ground conditions. Were a theme selected for this paper it would be: "Preserve the original roof in best condition possible by the use of smooth blasting techniques and fully grouted roof bolts — since the original rock is the best and cheapest material available for ground support." TYPES OF BONDED BOLTS As has been shown previously, there are several ways in which a bolt may be bonded. These are illustrated in Fig. 1 and 2. There are three general types of grouted bolts: 1) pretensioned, 2) post-tensioned, and 3) untensioned. The type which will be of most benefit to the user will depend upon the particular ground support problem involved. Despite the many arguments propounded for the necessity for using a tensioned bolt, ample evidence exists from actual experience that untensioned bolts can be effective in many instances. The outstanding characteristic of a grouted bolt is that it provides the user with a variety of rock consolidation techniques heretofore unavailable with conventional rock bolts. Many of the unusual characteristics of grouted reinforcing bar have been evaluated by researchers in the concrete structure field.&apos; Underground application has largely been pioneered in the construction field, with especially good work being reported from the Snowy Mountains Hydroelectric Authority in Australia. Techniques developed there using cement grouted bolts are now being adapted in many large government construction projects in this country with excellent results. The ap- plications described in this paper are those in which Cyanamid&apos;s Roc Loc Mining Kits were used exclusively. SLUSHER DRIFTS AND FINGER RAISES (BOX HOLE BROWS, DASHES) A common mining problem especially where block caving methods are applied is that of maintaining the roof in slusher trenches particularly at the intersections of the trench with the feed raises (box holes) through which the large fragments of broken ore tumble. Typical sections are shown in Fig. 3 and 4. In Fig. 3, the drift is normally driven 7 ft wide by 8 ft high initially. The rock involved is a hard norite (diabase) which is usually competent but has "block cleavage". This roof has a tendency to fall out in large blocks when subjected to operating stresses. Depending upon the initial condition of the roof, the drift is either lined with 2 to 3 ft of concrete immedi-

Jan 1, 1964

By E. M. MacKevett

The only source of uranium ore in Alaska that has been mined commercially is the Ross-Adams deposit, a gently inclined, fusiform orebody in alkali granite in which uranothorite and uranoan thoria-nit? ale the chief ore minerals. In mode of occurrence, apparent genetic association with the granite, and to a lesser extent in mineralogy, this type of deposit is uncommon. The mine is in the southern part of Prince of Wales Island (Fig. 1) at an altitude of about 950 ft on the southeast flank of Bokan Mountain. A steep unpaved road 1 3/4 miles long leads to the dock on the West Arm of Kendrick Bay, which can be reached by boat or seaplane from Ketchikan, some 35 miles to the northeast. The southern section of Prince of Wales Island is covered by dense forests interspersed with swampy tracts of muskeg. Most of the higher peaks support only sparse vegetation, and in areas underlain by alkali granite bare rocky slopes prevail to as low as 800 ft. Numerous fiord-like embayments penetrate this part of the island, and their shorelines provide near-continuous rock exposures. Rainfall is heavy, about 150 in. annually. Throughout the year the climate is relatively mild. History and Production: In May 1955 two members of a Ketchikan prospecting group, Don Ross and his wife, found the deposit while working with an airborne geiger counter. Later they confirmed their discovery by ground investigations. During the summer Climax Molybdenum acquired controlling interest in the property and started exploratory diamond drilling, resuming the drilling on a larger scale in the summer and fall of 1956. Climax began mining in July 1957, shipping the ore by barge and train to the Dawn Mining Co. mill at Ford, Wash. The open pit workings, about 370 ft long, between 25 and 75 ft wide. and 25 ft deep (shown in Fig. 2) were shut down in October 1957. As of September 1958 the pit was still inactive, although a small tonnage of known reserves remains in the southern part. The operators believe the 15,000 tons of uranium ore already produced will average 0.80 pct. GEOLOGY The Ross-Adams mine is within a small stock or boss of alkali granite, about 1000 ft from the southeast margin of the granite (Fig. 3). The area around the boss is underlain chiefly by plutonic rocks of intermediate composition and by metamorphosed sedimentary and volcanic rocks. The oldest rocks in the area probably are the metamorphosed volcanic rocks that are well exposed adjacent to the South Arm of Moira Sound. They are considered by Buddington and Chapin1 to be of Devonian age. These light gray to dark gray rocks mainly represent a layered volcanic sequence. They are commonly porphyritic with plagioclase pheno-crysts in an altered, fine-grained groundmass. The

Jan 1, 1960

By H. N. Mills

The glass industry is a major user of many industrial minerals in the manufacture of its product. It is the intent of this chapter to: (1) acquaint the reader with the glass industry by including a few production statistics, and (2) cover the various aspects of the major raw materials used to make glass. The matter of glass compositions, properties, and batches is considered beyond the scope of this chapter which deals only with raw materials. For more details on the particular minerals and rocks used in glassmaking, the reader is referred to chapters in the commodity section of this book. Glass Industry Statistics Glass manufacture in the United States can be divided into three major product classifications as follows: 1) Glass containers 2) Pressed and blown glass 3) Flat glass Glass containers include bottles and jars for the packaging of food and beverages, as well as drugs, chemicals, and cosmetics. Pressed and blown glass includes table, kitchen, art and novelty ware, lighting and electronic glassware, and fiber glass. Flat glass covers sheet or window glass, plate, laminated, and safety glass. The US Department of Commerce statistics, as recorded in the 1977 Census of Manufacturers, compares the dollar value of glass shipments for each product category. These statistics are shown in Table 1 (Anon., 1980) and are self-explanatory. A comparison of the tonnage output in each product classification is difficult, as production data is reported in "gross" for glass containers, "pounds" for fiber glass, "pieces" for glassware, [ ] and "square feet" for flat glass. In the case of glass containers, an average "pounds per gross" factor can be applied to the total production figures reported in thousands of gross in Bureau of Census industrial reports. Table 2 presents the calculated annual production tonnage for glass containers for the years 1974-1979. Except for 1979, there was a yearly increase in production. The tonnage figures of Table 2 are further influenced by decreasing weight per gross which has occurred in the glass container industry since 1975. This reflects the gradual shift to lighter weight containers for beverages. Other segments of the glass industry have experienced growth, but the figures in tons are not published information. Fiber glass growth has been influenced by the heavy demand for insulation as part of energy conservation efforts on a national basis. The production of flat glass by the float process has continued to grow with several new plants entering production. All portions of the glass industry experienced the effects of the general economic decline of 1979-1980, but the outlook for the future is bright. Batch Materials For Glass Use Materials and Function Soda-lime-silica glass represents the largest proportion of glass manufactured for commercial use. It is produced by the fluxing and

Jan 1, 1983

Both drilling and production of oil decreased in Rumania during 1935. The drilling totaled 1,042,041 ft. and production 61,973,938 bhl., being a decrease of 8.5 and 1.6 per cent, respectively. Wells completed during the year totaled 198, of which 168 were oil wells, compared with 238 and 215, respectively, of 1934. No important discovery was made during the year. The only new field found was Valea Calugareasca, where the Credit Minier completed a small well on the westward plunge of the anticline. Drilling higher on the structure will probably prove the field to be of greater importance than the results of the discovery well indicate. The only other developments of importance were the extension of the Bucsani field, the opening up of a new area on the northeast of the salt at Moreni by Credit Minier and a minor extension of the West Gura Ocnitei field. At Calinesti, on the cast extension of the Moreni field, exploration work continued and a gas well was completed, but oil in commercial quantities is yet to be found.

Jan 1, 1936

Both drilling and production of oil decreased in Rumania during 1935. The drilling totaled 1,042,041 ft. and production 61,973,938 bhl., being a decrease of 8.5 and 1.6 per cent, respectively. Wells completed during the year totaled 198, of which 168 were oil wells, compared with 238 and 215, respectively, of 1934. No important discovery was made during the year. The only new field found was Valea Calugareasca, where the Credit Minier completed a small well on the westward plunge of the anticline. Drilling higher on the structure will probably prove the field to be of greater importance than the results of the discovery well indicate. The only other developments of importance were the extension of the Bucsani field, the opening up of a new area on the northeast of the salt at Moreni by Credit Minier and a minor extension of the West Gura Ocnitei field. At Calinesti, on the cast extension of the Moreni field, exploration work continued and a gas well was completed, but oil in commercial quantities is yet to be found.

Jan 1, 1936

By Harold M. Mooney

RESISTIVITY measurements for determining depth to bedrock, water table, and other geo- logic discontinuities have had only limited success. Many of the difficulties can be attributed to complex geology and to basic limitations of the method; current flow through a continuous medium is a diffusion phenomenon, emphasizing irregularities near the source and smoothing out those at a distance. Some of the failures, however, are due to careless field work and incompetent interpretation. A forthcoming publication1 may help to reduce difficulties of this sort. The writer here attempts to bring order into the multiplicity of interpretation methods and, to a limited extent, to evaluate them. For all methods, the field data to be interpreted consist of apparent resistivity values plotted against electrode separation, Fig. 1. The interpretation should give depths to one or more geologic horizons. Direct currents and the Werner four-electrode configuration will be assumed, since these are widely used, although the interpretation problems remain essentially the same for other electrode configurations. Alternating currents higher than, say, 20 cycles per second introduce complications beyond the scope of this paper.

Jan 9, 1954

Geological Survey of Alabama, University, Ala. A complete list of publications will be sent upon request Requests for publications should be addressed to Walter B. Jones, State Geologist, University, Alabama Publications of the Survey, of most interest to the general public, comprise (1) Special Reports, (2) Monographs, (3) Bulletins, (4) Circulars, (5) Maps The Special Reports mostly deal with a special coal field, mountain, valley, or series of formations, while the Monographs treat of some industry, resource, or group of organisms throughout the state or as far as it extends The Bulletins deal with a variety of subjects, but are usually smaller and less technical than the Monographs and Special Reports Maps now available comprise a map of the Cahaba coal field, one of the Coosa coal field and a small geological map of the state, in addition to a large geological map, 28 by 42 inches, 8 miles to the inch (1926) (also bound with Special Report 14) Price of the large geological map of Alabama, folded in manila envelope, is $1.03 postpaid

Jan 1, 1933

By E. E. ELLIS

THE zinc deposits under development by the Universal Exploration Co., a subsidiary of the United States Steel Corporation, are close to Jefferson City, Tenn., a small town about 30 miles northeast of Knoxville, Tenn., and are served by the Southern Railway. The first zinc mining in this district was in the old Mossy Creek mine at the north edge of the town, opened for oxidized ores in 1871 and later worked for sulfide ores. An oxidized zinc ore deposit (carbonates and silicates) was opened near New Market in 1900 and worked through the war period by the G1&apos;8sselli Chemical Co., producing around 25,000 tons of oxidized ore. In recent years a sulfide deposit has been found and developed but is not producing. About 1% miles south of this a small body of sulfide ore was developed by open cut, but the operation was unsuccessful. The Universal Exploration Co. entered the district in 1926 and, after extensive exploration, has been operating an oxidized ore-body since Janual:y, 1928, and has been developing a sulfide ore body since July, 1928.

Jan 1, 1929

Reports on process control computer projects at the Kamioka Plant are summarized from the Japanese technical literature (see references). Fluidized Bed Roaster and Sulfuric Acid plant1 A small process control computer (Yokogawa CCS-200 with an OKITAC 5090P 8K central processor) was installed in the Kamioka smelter in the summer of 1964. A year-and-one-half installation project followed, which successfully brought the roaster and acid converters under computer control. The process plant consisted of two 130 RPD fluosolids roasters and two Monsan to acid units. The roasters are charged with lead-zinc concentrates with SO2 from the roaster processed to sulfuric acid. The computer system provides the following functions: 1) log data from the plant--the input is taken from 50 analog signals, 130 high-low digital alarm points, and 50 analog high- low alarm points; 2) set-point control on 18 control loops; 3) direct digital control (DDC) on eight control loops for which conventional controllers were difficult to adapt due to abnormal loop characteristics or delay times; 4) execution of a safe shut-down procedure

Jan 1, 1969

By M. E. de Morton

Low frequency-internal friction measurements on annealed chromium have shown a marked increase in damping below - 40°C which is strongly strain amplitude dependent. An interpretation of these results is given in terms of the motion of antiferromagnetic domains assumed to exist below - 40°C. A time effect on internal friction was measured after slight overstraining. After heavy deformation a pemzanent, five-fold increase in internal friction was observed at -45°C and the character of the internal friction us temperature curve markedly changed. Full recovery of damping was not attained until after heating to 800°C. A qualitative interpretation of some of these effects is given. THE aim of this preliminary investigation was to study the internal-friction characteristics of chromium containing comparatively small quantities of interstitial solutes in the fully annealed and heavily worked condition. Marked anomalies in a number of physical properties of chromium at temperatures near 40°C have been observed1 and an investigation by neutron diffraction&apos; has shown that chromium at room teyperature is weakly antiferromagnetic with a Nee1 temperature at approximately 200oC. No irregularities in the degree of antiferromagnetic ordering have been observed at -40°C, the transition temperature, and a complete explanation of this transition in chromium is still awaited. Recently weiss3 has suggested that an ordering effect of nitrogen in the face-centered interstices of the bcc lattice of chromium could be responsible for the superlattice detected below 200 °C in the neutron diffraction experiments. EXPERIMENTAL MATERIAL AND METHOD Specimens 10 by 0.030 in. diam were prepared from ingots of arc-melted electro-deposited chro-

Jan 1, 1961