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By Paul W. Mayne

The axial load-displacement-capacity and load-transfer response of deep foundations can be conveniently assessed by geophysical piezocone tests that provide four independent readings with depth, including tip stress (qt), sleeve friction (fs), porewater pressures (ub), and shear wave velocity (Vs). The penetration data (qt, fs, and ub) of the CPT are utilized to obtain the pile side friction (fp) and end bearing capacity (qb) while the shear wave measurements provide the initial stiffness. Within an elastic continuum framework, the axial pile deflections are calculated and an approximate nonlinear response is obtained by modulus degradation from small-strain response (G0) to intermediate- and large-strains (G). The continuum solution permits separation of load transfer along the sides and proportion to the base. Applications are shown for case studies involving an end-bearing drilled shaft, two friction-type drilled shafts in Alabama and Georgia, and a "Class A" prediction involving driven pipe piles in residuum of the Atlantic Piedmont geology. Load-transfer data were available for the drilled shaft foundations.

Jan 1, 2002

By Harry R. Cedergren

Properly designed drainage systems can be of great benefit to many kinds of Civil Engineering works, including embankments, and often are the most economical way to protect such works from the damaging effects of water. To function properly, drains must be able to remove water without also removing soil or becoming clogged with soil or erodible rocks. The first criterion to be used in designing drainage systems, called the filter criterion, can prevent all such problems (erosion and clogging) when properly fulfilled in design and construction. The second requirement of drains is that they must be capable of removing all of the incoming water without the build-up of large amounts of head that can damage the protected works. To insure this kind of perfomance, the discharge capabilities of drains should always be verified by appropriate hydraulic and seepage calculations. This paper describes these two basic drain design criteria and also gives examples of application of seepage principles to the evaluation of the potential benefits of drains and to the design of drains for mine waste embankments.

Jan 1, 1985

By William G. Pariseau

A plasticity theory for anisotropic geologic media has been applied to the problem of quasi-static wedge penetration of rock under confining pressure. Numerical evaluation of the governing system of stress equations in the transversely isotropic and orthotropic cases using representative material properties shows that the consequences of initial anisotropy for the penetration process are by no means trivial. In the transversely isotropic case, a threefold increase in the vertical force required for penetration to a unit depth occurs as the inclination of the axes of anisotropy are rotated through 90° with respect to the penetration path. The horizontal force required varies from zero to a maximum at approximately 60° then back to zero as the axes of anisotropy are rotated. The maximum is of the order of magnitude of the force required in the isotropic case. Similar results are observed in the orthotropic case. Practical aspects of the post-elastic phenomena associated with anisotropic rock indentation within the context of drilling problems include: bit yaw, hole deviation and bending stresses in the drill rod, all of which vary with strata dip but which can be quantitatively evaluated given the bit geometry, interface friction and rock properties. In a broader context, the analysis reveals the necessity for well conceived experimental work and sound theoretical research concerning post-elastic behavior of geologic media as a function of confining pressure, the effects of induced anisotropy, and the variation of strength parameters with loading path changes in the post-elastic range.

Jan 1, 1971

By E. C. Harder

SINCE early in 1916, when it became apparent that the steel industry of the United States could not depend, for the duration of the war, on several important foreign sources of manganese and might have to depend entirely on domestic ores, the U. S. Geological Survey, with the assistance f several cooperating organizations, has made a comprehensive investigation of domestic manganese resources. The work has included field studies in a number of states as well as annual, quarterly, and monthly canvasses among operators concerning current and future production. In order that the interested public might have access to the important results of the studies, preliminary reports concerning the field work as well as periodic summaries of production were issued as promptly as possible. Although large deposits of rich manganese oxides appear to be lacking in the United States, small deposits of high-grade material are numerous and widely distributed and large low-grade deposits are found in several places. The principal districts in which high-grade manganese ore is mined, in the order of their importance as recent sources of production, are: Philipsburg district, Mont.; Butte district, Mont.; Southern Nevada region; Central California region; Bisbee district, Ariz.; Appalachian region of Virginia; Batesville district, Ark.; Tintic district, Utah; and Cartersville district, Ga. Scattered deposits of some importance are found in western Arizona, southern California, eastern Tennessee, southern Oregon, and central Utah. The formation of many manganese oxide deposits appears to be related to the physiographic histories of the regions in which they occur.

Jan 5, 1919

By H. R. Green, D. M. Lamb, A. D. Taylor

The design of slurry launders has usually been based on strictly empirical concepts. An examination of the most common procedures reveals that they do not account for many of the variables that are recognized as significant for slurry transport. These may include flow rate, volume concentration of solids, solids specific gravity, solids size distribution, particle shape, launder geometry, and roughness of the wetted surface. It was decided to develop a design procedure, which would accomplish two things: First: Take into consideration most of the known significant variables and systematize the procedure to assure consistent results. Second: Provide a rational basis for examining and utilizing operating data to refine and improve the system. To accomplish this, it was necessary to develop a basic design concept. This concept has been developed through a complex development history, and yet still appears workable and technically sound. That concept may be outlined as follows: First: The solids transport velocity is the fundamental basis for slurry launder design. Second: The stream configuration, hence the launder size, is integrated with the solids transport velocity so that the actual stream velocity exceeds the solids transport velocity. Third: The launder slope is that which will achieve the

Jan 1, 1979

By Gerald T. Homce, Michael R. Yenchek, H. Kenneth Sacks, James C. Cawley

Abstract—Overhead electric power lines present a serious electrocution hazard to personnel in a variety of industries. Overhead lines, typically uninsulated conductors supported on towers or poles, are the most common means of electric power transmission and distribution, and are exposed to contact by mobile equipment such as cranes and trucks. Equipment contacting energized overhead lines becomes elevated to a high voltage, and simultaneous contact by personnel of the “hot” frame and ground can cause serious electrical shock and burns. Industries where risk of these accidents is greatest include construction, mining, agriculture, and communications/public utilities. An estimated 2300 accidental overhead line contacts occur each year in the U.S. This paper describes a practical low-cost concept to detect actual contact of mobile equipment with a high-voltage line and provide a warning. Accident statistics indicate that more than half of the fatalities could be prevented by such a device. Index Terms—Crane, electrical shock prevention, engineering control, mining, mobile equipment, power line.

By P. D. Rao, D. E. Walsh

A pilot-scale study was performed to evaluate the potential for gravity concentration of gold from -13 mm (-1/2 in.) crushed ore from Ester Dome, AK. 9.04 t (9.94 st) of crushed ore were sampled and processed through a Pan-American jig-Wilfley table pilot plant. Plant products were sampled for assay and material balance calculations. Gold recovery through one stage of jigging and two stages of tabling was 17.4% at a concentration ratio of 615:1. Concentrate grade was 766.3 g/t (22.4 oz/st). The feed grade to the plant was calculated at 1.71 g/t (0.05 oz/st). Jig tailings, primary table tailings and secondary table tailings grades were 1.44 g/t (0.042 oz/st), 1.30 g/t (0.038 oz/st), and 5.47 g/t (0.16 oz/st, respectively. Significant coarse, free-milling gold values were shown to remain in the, jig tailings. Concentrate mineralogy is discussed.

Jan 1, 1992

George E. Collins, Nacoochee, Ga. (communication to the Secretary): The results tabulated below were obtained at the Reynolds mill, White county, Ga. They were noted, not with a view to investigating the point discussed by Mr. Clark, but in course of a test on a working scale to determine the com parative saving from a given free-milling ore on copper and silvered plates respectively. In every case the bullion assayed was the result of a separate clean-up on a considerable quantity of ore. The ore varied widely in grade and in other respects, but the runs bracketed in the table were made at the same time, in adjoining batteries, and on similar types of ore. In a * Result modified by the addition to the bullion-shipment of a little impure bullion left over from previous clean-ups.. On these occasions, the strips of copper were removed from the tables, and: their lower surfaces were cleaned. Hence the higher yield reported.

Jan 1, 1900

By Thomas Buenger

The Hamburg smelter of Norddeutsche Affinerie AG is situated near the city of Hamburg’s downtown and is therefore particularly subjected to fulfill environmental requirements according to the German legal regulations. Thus, investments related to increasing concentrate throughput are always linked to packages to enhance the emission status of the smelter. This connection between environmental protection and productivity enhancement should be explained by the example of the Peirce-Smith converter plant of the Hamburg smelter. Such outstanding investments can be demonstrated by the transition from scrap charging via boat from the front side to a fully automatic and completely sucked scrap charging system.

Jan 1, 2009

By John W. Pack

At present the manufacture of metallic zinc, or spelter, in Missouri, is carried on only at the establishments located at Carondelet, or South St. Louis. Although the development of the industry has not yet reached that fulness which it has attained elsewhere in the United States, still the commanding advantages of position of these establishments are so evident that the prospective importance and magnitude of spelter manufacture in this State, and especially at this locality, can hardly be doubted. A study of the chemical and technical aspects of the business of these points cannot be without interest to the metallurgist as well as to the capitalist. I have endeavored to investigate, as far as was practicable, within the limits of a paper of this character, some of the problems connected with this industry, at the same time making a few comparisons of the results attained at some of the Carondelet works with those of other establishments with regard to which information could be obtained. In the prosecution of these studies I have been kindly aided by the managers of Carondelet establishments, and by Prof. Charles P. Williams, Director of Rolla School of Mines. To the latter I am especially indebted for assistance in regard to methods of analysis. To all these gentlemen I return my thanks for their valuable aid. Other sources of information will be duly credited in their proper places.

By John W. Pack

AT present the manufacture of metallic zinc, or spelter, in Missouri, is carried on only at the establishments located at Carondelet, or South St. Louis. Although the development of the industry has not yet reached that fulness which it has attained elsewhere in the United States, still the commanding advantages of position of these establishments are so evident that the prospective importance and magnitude of spelter manufacture in this State, and especially at this locality, can hardly be doubted. A study of the chemical and technical aspects of the business of these points cannot be without interest to the metallurgist as well as to the capitalist. I have endeavored to investigate, as far as was practicable, within the limits of a paper of this character, some of the problems connected with this industry, at the same time making a few comparisons of the results attained at some of the Carondelet works with those of other establishments with regard to which information could be obtained. In the prosecution of these studies I have been kindly aided by the managers of Carondelet establishments, and by Prof. Charles P. Williams, Director of Rolla School of Mines. To the latter I am especially indebted for assistance in regard to methods of analysis. To all these gentlemen I return my thanks for their valuable aid. Other sources of information will be duly credited in their proper places.

Jan 1, 1875

By A. R. Denison

This field in 1933 continued as in 1932, although to a much less extent, to dominate the drilling and production situation throughout the oil business. The 2466 producers completed in this field during the year are 28 per cent of such wells completed in the United States. The 2556 completions reported in the five counties within which the East Texas field lies are 21 per cent of all such wells reported in the United States. It follows that with such a command of the development situation, every other factor with regard to this field has an important bearing on the entire oil business. As a consequence, the important developments in the East Texas field are the important developments of the year. Very little new productive territory was added to the already known limits of this enormous field. On the other hand, drilling has shown that with a few very minor exceptions this field is a continuous productive area, with a regular outline and no "dry spots" other than that of a single well surrounded by producing wells. Drilling was confined to the already proven limits of the field. This consisted essentially of more adequate coverage of leases by wells, the meeting of required offsets and the drilling of a large number of small tracts which developed from subdivision of larger leases due to court action and other causes. The allowable throughout the year was, with minor variable factors, on a per-well basis. With the steady decline in per-well allowable after May, every operator was faced with declining

Jan 1, 1934

By Kudret Tutuk, Serkan Saydam, Sungsoon Mo

"This paper presents an overview of the floor heave management at the Glencore Bulga Underground Operations and investigates the contributing factors to the behaviour of the floor. The mine experienced a number of major floor heave events in gateroads on development. As the longwall face approached the roadways, the magnitude of floor heave frequently increased, while new floor heave also developed. Furthermore, severe floor heave events took place along the longwall face. The most observed failure mode was buckling. While regular floor measurements were conducted to better understand the nature of the phenomenon, and various measures were considered to control the deformation of floor, the mining height was increased for the predicted floor heave domains, which facilitated effective management of the floor issues. The experience in the mine indicates that mainly high horizontal stresses with greater depths of cover and certain types of floor lithology configuration are likely to contribute to the failures of floor strata.INTRODUCTIONThe Glencore Bulga Underground is located in the Southwest of Singleton in the Hunter Valley of New South Wales, Australia. Blakefield South, part of Bulga Underground, commenced longwall mining in 2010, extracting coal from the Blakefield seam, while the overlying longwall panels were previously mined from the Whybrow seam. The coal seam ranges from 4.5 m to 8.0 m thick with the mining heights varying from 2.9 m to 3.5 m. The longwall panels are 320 m and 400 m wide and up to 3.5 km long.The mine experienced a wide range of floor issues around longwall panels LW7 and LW8, both 400 m wide. For instance, the concrete floor in the travel road failed and lifted as the longwall retreated in close proximity as can be seen in Figure 1. Figure 2 shows the beam stage loader (BSL) buried into the lifted floor, and Figure 3 shows a timber prop distorted due to the movement of the floor. In addition, severe deformation of the floor along the longwall face impeded the longwall operation, as shown in Figure 4."

Jan 1, 2018

By E. G. Kelly

This paper describes the performance of a modern compound trough profile spiral that is optimized for fine coal cleaning. Reduced performance (Tromp) curves are presented to compare these new spirals with older designs, as well as with other commonly used coal cleaning equipment. As an aid to equipment selection and circuit design, data are also presented to show how variables, such as flow rate, pulp density, and particle size affect efficiency and the separation specific gravity.

Jan 1, 1984

By Changping Hu, Keqin Tan

In 1937, the Metallurgical Department of the National Resources Committee established a copper refinery plant (predecessor of the Chongqing Smelter) in Changsha, Hunan Province, China. The blister copper produced by a local copper smelter was casted as anode for electrorefining. The plant, with a capacity of one ton of electrolytic copper per day, was designed and tested in 1937. At the trial production stage, a total of 9 tons of cathode copper was produced. The plant was formally put into operation in July 1938. In the same month, more than 20 tons of electrolytic copper with purity over 99.9%Cu was produced. This was the first batch of electrolytic copper produced in China. In 1939, China’s largest non-ferrous metal smelting plant, Fengtian Gold Mine Refining (predecessor of the Shenyang smelter) was completed and put into operation in Shenyang, mainly producing nonferrous metals such as gold and silver, as well as copper and lead. In 1939, the Kunming copper smelter (predecessor of Yunnan Smelter) was completed and put into operation. The plant equipment, imported from the United Kingdom, was designed to produce 1,200 tons of electrolytic copper annually. In 1943, Jiatong smelter (predecessor of the Shanghai Smelter) became the 4th domestic cathode copper producer. Since 1949, China has gradually established a large copper industry. These developments are discussed in this paper. Today, China operates nine out of the twenty largest copper refineries in the world. With a total capacity approaching 9 million tons of copper per year, China has the world’s largest copper refining capacity. INTRODUCTION China is a country with a long history of copper mining. The earliest smelter in China in recent times was the Shanghai Smelter, which was built in 1912. From then until 1949, China successively built Chongqing Smelter, Kunming Smelter and Shenyang Smelter. The world's first copper electrorefinery was the Pembrey refinery built in the UK in 1869 (Lu, 1999). However, it was not until 69 years later that the technology was spread to Changsha, China.

Jan 1, 2019

By S. Potgieter-Vermaak

The main mineral components of the so-called heavy sands (or black sand) are the titanium, zirconium and iron-bearing minerals, rutile, zircon and illmenite, accompanied by various minor and trace amounts of silicates or phosphates, often present together with the rare earth elements. The investigated samples originated from Richards Bay Minerals (RBM) in South Africa, which is jointly owned by BHP Billiton and Rio Tinto, the largest titanium slag producer in the world. The present study focused on the characteristics of samples originating from various points in the separation plant. The heavy-mineral fractions and concentrates of a representative suite of samples were investigated using various analytical techniques to establish the differences in morphological and elemental compositions at the different points in the plant. These techniques included: reflected light microscopy, micro-raman spectrometry (MRS), scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDX) and structural and chemical analyser (SCA). All samples comprised a heterogeneous population of zircon and rutile grains with diverse physico-chemical properties, expressed by large differences in colour and trace element chemistry of single grains. The elemental composition proved the presence of the rare earth elements that appeared to coexist with both Ti and Zr minerals. The percentage of grains hosting inclusions, such as anatase, monazite, quartz, spessartine, augite, epidote and actinolite, varied for each sample and could be uniquely characterized by Raman investigations. Keywords: heavy mineral sands, micro-ram an spectrometry, elemental analysis

By R. S. Shoemaker, F. W. McQuiston

EMPEROR GOLD MINES Vatukoula, Fiji 1974 Operating Data to July 1 ORE DESCRIPTION: Ore bodies occur in basalt and associated ash beds overlain by andesite tuffs and sediments. The basalt in much of the ore mined is weathered with alteration of olivine to serpentine and iron oxides, and augite to chorite. The most important host minerals for gold are the tellurides sylvanite and hessite. Next in importance the sulphide s, pyrite, marcasite and arseno-pyrite. A small amount of free gold also occurs. Chalcopyrite, sphalerite, tetrahedrite, bornite, galena and native tellurium are present in small quantities. TYPE OF MINE: Underground and open pit ORE HAULAGE TO MILL: 3.5 ton bottom dump skips from underground. 7 ton trucks from open pit. CAPACITY IN TONS/24 HRS: 1345 short tons ASSAY HEADS (1973): 0.232 oz Au per ton, 0.357 oz Te per ton PRODUCTS: Gold Bullion (400 oz bars) Metallic Tellurium (1 2 lb bars ) RECOVERIES: AU 86.2% Te 88.0% ORE GRINDABILITY: 9.25 Kwh/T TOTAL POWER: 25.7 Kwh/T WATER: Pumped 112 mile to a 318, 000 gallon head tank. Consumption: 2 140 gal per ton, no reclaimed water used. TAILINGS: Pumped 2 /3 mile through 8" pipe. Uphill sections are steel. Downhill sections are fibro asbestos.

Jan 1, 1975

Hoisting ropes are constructed of wires and strands positioned helically around the axis. This helical positioning causes that, in the rope loaded at the end with the weight Q, the longitudinal displacement u, axial force P, torsional displacement v and constant torsional moment M are generated. More over, the proper weight of the rope q gives the force acting along the axis of the rope. This force changes its value from 0 at the bottom to qL at the top. This force gives, along its length, a variable torsional moment making the rope rotate. During the movement of the conveyance downwards the falling part of the rope rotates, which makes it untwist on the section up to the half-depth of the shaft and twist on the other half-depth. As the result, the twisting lay of the rope changes increasing in the upward direction and decreasing downwards. The angle of twist of the strands changes in an apposite way. When moving upwards, the uplifted rope does not twist and retains its state of deformation up to the moment when it passes over the pulley. Next, the cycle of untwisting and twisting repeats during the movement of the other conveyance downwards. This phenomenon is known from mining practice. It was also analysed, in the works of Glushko (1966) and Popowicz (1963).

Jan 1, 1995

By H. V. Makar

A study was conducted by the Bureau of Mines to determine problems associated with the use of ferrous fractions from urban refuse as melting stock for steelmaking and to evaluate the resulting steel products. The study involved 50-pound ingots from laboratory melts and 50-pound ingots from 1-ton electric-arc-furnace melts. The 50 pound ingots from the laboratory melts and the arc-furnace melts were hot rolled to provide material for mechanical and corrosion testing. Results obtained in the study include the following: Most steels rolled successfully and exhibited acceptable surface and edge condition. Tensile strengths of the plain carbon steels were not significantly affected by copper up to concentrations of 0.65 pct and were not affected by tin content up to 0.16 pct. Yield strength increased with increasing copper and tin contents, and impact strength decreased with increasing tin content. Hardness increased slightly with increasing copper content. In general, properties of the steel produced were not measurably affected by charge composition (that is, melting stock), melting practice, or method of scrap preparation.

Jan 1, 1975

By Manish Kumar

One of the recent advances in the field of testing of concrete piles is the Non-Destructive testing (NDT) of piles. This paper deals with a specific project where this technique was employed along with an extensive program of conventional testing methods to cross check the results. Conventional testing of the Bored, cast-in-situ piles involved taking full length concrete cores from piles to check physical properties such as core recovery, RQD, crushing strength and density of concrete. Additionally, a number of questionable piles were exposed and inspected and actual load tests were performed on selected piles. Concrete pour cards were used to compare actual Vs theoretical consumption of concrete. A direct comparison of the conclusions drawn from both these testing methods provided an excellent opportunity to better understand the intricacies of NDT technique. The study undertaken clearly indicated a need for developing clear guidelines and specifications for the use of this method of non-destructive testing of piles before the .method can be accepted as a useful quality control tool at the construction sites.

Jan 1, 1996