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By Bret N. Lingwall, Byron Foster

The problem of reliable extreme event modeling of large diameter piles under enormous structural or kinematic loads has gained more attention in recent years. In particular, the soil response around the foundation and impacts to buried adjacent infrastructure has gained interest. One of the principal shortcomings with analysis of large diameter pile foundations under extreme event lateral loading is the reliance on conventional beam on elastic foundation methods, which do not model the soil field response around the pile. These methods are limited for large displacement problems, and for large diameter piles. However, the fundamental interactions between steel and concrete, and structure to soil are difficult to constrain, especially in large strain problems where the structural elements become inelastic. The non-linear interaction of the structural materials and soil is desirable so that assessment of stress changes in the field and effects on adjacent facilities can be modeled. A numerical modeling methodology that addresses these shortcomings has been developed. This method utilizes the interaction of brittle concrete with discrete steel reinforcing and casing in a robust manner capturing inelastic non-linearity in both soil and structure. This paper presents a comparison study of the method, wherein three different validation studies were made to data from full scale laterally loaded pile testing. INTRODUCTION Extreme event lateral loading of deep foundations comes in many forms including earthquakes, landsliding, tsunamis, hurricanes, surface fault rupture, liquefaction induced lateral spreads and many more. These extreme events induce loads on foundations far greater than service or strength loads. Perhaps the most dangerous extreme event loads are those of large soil displacements such as landslides, lateral spreads, and surface fault rupture, wherein the soil surrounding the foundations can move laterally 100 mm to 3 m! In these extreme event loading scenarios, small diameter foundations are pushed past their limits and many engineers prefer large diameter deep foundations for these situations. These deep foundations of diameter 900 mm or greater may be auger cast in place piles, cast in drilled hole piles, cast in steel shell piles, cased or uncased drilled shafts, bored precast piles, etc. For convenience in this paper, large diameter deep foundations will be referred to as Large Diameter Shafts (LDS). In LDS, steel may or may not used as a shell around the perimeter of the concrete and/or as internal tensile reinforcement. The interaction between brittle concrete and ductile steel within and/or along the perimeter of the LDS is critical to understanding the non-linear inelastic behavior of LDS for problems of large lateral displacements from extreme events.

Jan 1, 2018

CONTENTS: Broken Hill The mixing stations.Operating and mixing apparatus.Pulp distribution.Stope preparation.Filling procedure.Consolidation of old fill.Drainage:Pulp density tests. Life of sand pipe lines.Results.Advantages and disadvantages.Conclusion and acknowledgments.General remarks on South Limited.Mining methods.History of stope filling in Broken Hill.Need for a new and better filling method and transport system.Initial experiments with hydraulic stowing.Source of the sand.Water Supply.Signalling system.GENERAL REMARKS ON BROKEN HILL SOUTH LIMITEDThe South Mine, property of Broken Hill South Limited, is situated at Broken Hill, N.S.W., Australia, towards the southern end of the main lode.The leases (M.L's 7 and 8)' cover a length of 2,400 feet along the lode outcrop and the workings extend, at this date, to a depth of 1,940 feet below the collar of the original main shaft and to 825 feet below sea level.Mining operations have been continuous for about 58 years and during this period nearly 12.5 million tons of ore have been mined. The monthly tonnage extracted approximates 30,000 tons in normal times.The ore is a mixed sulphide containing galena and marmatite; the gangue minerals are principally calcite, rhodonite, quartz and garnet.A typical assay for a monthly period is 14·40/0 Pb., 5·6 ozs. Ag., and 11· 60/0 Zn. The whole of the ore is concentrated on the property by combined gravity and flotation methods. The lead and 'zinc concentrates produced are railed to other centres for the extraction of the contained metals.MINING METHODSMining practice throughout the field varies only in minor details. The ore-bodies forming the Broken Hill Lode lie within complex folds arranged along a shear and vary in size and mineralogical associations, but all the mines have similar types. Some of the ore-bodies have weak walls, but the chief difficulty in mining is caused by "heads" and "flaws" in the ore.Besides these local weak areas there are ground movements-referred to later-of varying magnitude extending throughout the central portion of the lode where the large ore-bodies, several hundred feet wide, approached the surface.

Jan 1, 1944

By M. Faraji

Inclusions formed in a high-carbon, manganese-silicon killed plain steel (Fe-0.77C wt%) were studied. Various techniques were used to characterise the inclusions, and the latter were classified according to their chemical composition, size and morphology. The main constituent elements entering the inclusions were Mn, S, Al, and oxygen. Alongside MnS and some Al2O3 inclusions many non-metallic inclusions appeared in complex forms, consisting of silicates, sulphides and oxides. Duplex oxy-sulphides, mainly MnS combined with Al2O3, or SiO2 were the most common complex multiphase inclusions in this steel. The nanoindentation technique was used to assess and rate different types of inclusions and data of the hardness and elastic modulus of individual inclusions at room temperature are presented.

Jan 1, 2010

Core samples, which were collected by the author from the Busang prospect, East Kalimantan, reflect a progressive evolution of a large magmatic-related hydrothermal system that is comparable to that encountered in many similar systems elsewhere in the Pacific region. The initial, localized deposition of sheeted porphyry quartz-molybdenite veins took place at high temperatures and fluid salinities, and at relatively deep levels. This was followed by an extensive phase of phyllic (sericite-quartz-pyrite ¦ tourmaline-apatite) wallrock replacement and vein formation. Propylitic (epidote-chlorite-carbonate-quartz) alteration was formed marginal to the phyllic assemblages. These porphyry-related events were centred in the Southeast Zone, and are probably associated with the emplacement of a felsic intrusion at depth. This event contributed only trace gold to the system. The early stages of hydrothermal activity were followed by an episode of quartz (¦ adularia) û carbonate û base metal sulfide veining, which was accompanied by argillic (illitic-kaolin clay) wallrock alteration. This event was sulfide-rich in the Central Zone and carbonate-dominated in the Southeast Zone. Gold mineralisation was observed in Central Zone drillcore to be associated with both sulfide, as well as carbonate, deposition. A final stage of epithermal-style quartz ¦ stibnite û realgar veins are, in the Central Zone, locally gold-bearing. The latter two events are interpreted to be associated with the late-stage exsolution of metal-bearing brines from the felsic intrusion that formed the earlier porphyry quartz-molybdenite veins and widespread phyllic-propylitic alteration.

Jan 1, 2002

By George K. Clement

Manual estimating method through use of equations, factors and curves for preparation of feasibility type estimates for capital and operating cost of mining and primary beneficiation in the United States and Canada of various types of minerals occurrences, except fossil fuels, using state-of-the-art technology. User should have basic estimating experience in the mining industry and/or related fields. Primary usage of this handbook will be for the preparation of preliminary estimate within a reasonable degree of accuracy with relative small amounts of hard input data. Output may be used to determine if a more finite type of estimate should be produced.

Jan 1, 1978

Sluice box operating practices in Papua New Guinea (PNG), and published work on sluice boxes are briefly reviewed. Some recent work on sediment entrainment mechanisms occurring in sluice boxes have also been described. In the light of this information, some drawbacks in the commonly adopted sluice box operating practices in PNG, and ways of overcoming them, are also highlighted.

Jan 1, 1991

By L. D. Gent

This report reviews the current state of the art of remote control techniques for underground continuous miners. A delineation of aspects requiring additional data is presented. Also a summary and delineation are presented in overview form for the related section functions: roof control, haulage, ventilation, power supply and rock dusting. The automated remotely controlled continuous miner project is a long-range research effort. However, the program has been divided into intermediate steps resulting in incremental production increases throughout the program. Data are developed relating the impact of our proposed research and development accomplishments to potential productivity impact.

Jan 1, 1975

By C. S. Samis, D. P. Seraphim

In the presence of oxygen, galena is oxidized in an aqueous medium containing ammonium acetate in accordance with the following reaction: PbS + 1/2 0, + 2 NH~Ac -» PbAc, + So + 2 NH: + H2O. This reaction was studied in an autoclave under oxygen pressure by polarographic measurement of the concentration of lead ion in solution. Oxidation rate is parabolic. The reaction products are lead acetote and elemental sulfur, the latter forming a film on the galena crystal. Reaction kinetics appear to be determined by the diffusion of lead from the galena phase to the solution interface through the film of sulfur. RECENT applications of pressure leaching on a commercial scale have emphasized the metallurgical importance of the oxidation of sulfide minerals in aqueous media by oxygen under pressure. Research experience has shown that sulfates, thio-nates, and metal oxides are the products of humid oxidation of sulfide minerals in basic solutions. The metal oxides may be solubilized in the presence of a complexing ion.' Certain oxide minerals are also amenable to treatment by this type of oxidation.' Several kinetic studies have been made of reactions of this type. Stenhouse' found that pyrite (FeS?) oxidized in a sodium hydroxide solution to produce a soluble sulfate and an insoluble layer of iron oxide and that the kinetics of the reaction were controlled by oxygen diffusion through the oxide layer. Andersen' studied the oxidation of galena (PbS) in a sodium hydroxide solution under oxygen pressure. He found the lead and sulfur to be simultaneously oxidized to produce plum bite ions and sulfate ions, and that the reaction rate was proportional to the surface area of the galena. The kinetics appeared to be determined by the reaction of oxygen and water with the galena surface. In each of the above reactions the metal and sulfur components of the mineral were oxidized simultaneously and at equal rates. In the present study the alkaline medium has been replaced by an approximately neutral solution of ammonium acetate in which lead sulfate is soluble. Under the conditions no sulfate was produced and no sulfur could be detected in the solution. The metal component of the mineral was solubilized and the liberated sulfur remained as a film of elemental sulfur on the surface of the galena crystal. A kinetic study of this reaction was undertaken to establish the kinetic mechanism and to determine the rate controlling step. Specific reaction rates were determined by oxidizing crystals of galena of measured surface areas in an autoclave maintained at the desired temperature and oxygen pressure. The rate of reaction was followed by measuring the concentration of lead in the ammonium acetate solution with a cathode ray polarograph, employing stationary platinum electrodes incorporated in the autoclave. Experimental Materials and Equipment Crystals of galena obtained from Violamac Mines, Retallack, B. C., were selected for oxidation because

Jan 1, 1957

By John D. Sullivan, Alfred P. Towne

"In copper percolation-leaching plants the ore is usually crushed to a maximum size of about three-eighths inch. Ordinarily an ore is crushed as finely as feasible since the rate of extraction of copper is increased with decreasing size of particles owing to the greater surface exposed and. the shorter path required for solutions to come into contact with the minerals to be dissolved. However, greater degree of crushing also increases the amount of fines. When ores are charged into leaching vats the coarse and fine material tend to segregate, resulting in channeling of solutions and leaving the areas where fines predominate only partly leached. An improvement in the method of charging the ore into vats that would minimize the deleterious effects of the segregations of fines would increase the percentage extraction of copper.The Inspiration Consolidated Copper Co.4 recently installed classifiers to remove the primary slimes from the ore, before charging it into the leaching vats. This necessitates a separate agitation treatment for the slimes.Recent publications5 of the bureau have shown the advantages of agglomeration followed by trickle leaching to extract copper from concentrator tailings. It was shown that when equal parts of ore crushed to about 1/4-inch size and concentrator tailings were agglomerated with approximately 10 per cent of moisture, either in the form of water or leaching solution, and the mass was charred into a leaching vat the ore could be treated successfully by open-drainage trickle leaching. Even with 30 or 35 per cent of minus 200-mesh material present the ore could be leached, if it was not flooded with solution.The results obtained in agglomerating ores and slimes suggested the possible advantages to be gained by wetting the crushed ore for standard percolation-leaching plants before charging it into the vats. Wetting the ore whould make the fine material and slime cohere to the larger pieces of ore thus tend to prevent segregation when the ore is charged into the vats. The bureau, at its southwest Experiment Station and in cooperation with the Department of Mining and University of Arizona, Tucson Ariz., therefore made a study to work: out A way in which slimes could be handled in percolation leaching. The study showed that the method of charging ore into the leaching vats governed the distribution the fines and consequently the rate extraction of copper. The results of the study reported in this paper."

Feb 1, 1931

By M. R. Pickus, I. W. Pickus

ORDINARILY age-hardening is thought of as being associated with a limited solubility of one metal in another. Much less has been written about the type of age-hardening that attends the formation of superstructures. Solid solutions generally have a disordered or random arrangement of atoms; that is to say, in a unit cell, such as that of the face-centered cubic lattice, there is no distinction between atomic sites. Atoms of a given metal may occupy cube corners or face centers. Under certain conditions, however, some alloys develop what is known as an ordered structure. In this case, cube corners would be occupied by only one type of atom and face centers by another type, Associated with this ordering process are many interesting changes in physical and electrical properties. Moreover, in many instances the alloys become susceptible to age-hardening. From the evidence now to be described, it appears that age-hardening in 14-carat gold alloys is due to the formation of both a super-structure and a precipitate. Alloys of the metals gold, silver and copper were known in antiquity. The available knowledge regarding their constitution has been ably summarized and extended by Sterner-Rainer,1 Janecke,2 Carter,3 Wise,4 and Coleman.5 Despite the long familiarity with these alloys and the numerous investigations of their properties that have been made, there is still much that remains unexplained. It has been known for a long time that the hardness of these alloys is closely related to the rate of cooling, Similar changes have been observed in the binary gold-copper system,6 one alloy of which corresponding to the formula Cu3Au, has been the subject of a careful and competent report by the English investigators, Sykes and Evans.7 They have established the fact that the shift of atoms from the ordered to the disordered condition takes place in some critical temperature range. At temperatures above the critical range the structure is random, and at temperatures below it the structure is ordered. No difference between these two structures is revealed by the microscope. Both have a face-centered cubic lattice and complete solubility, so that there is no evidence to suggest that the changes in properties are associated with a phase change, The more slowly the alloy is cooled, the higher is the degree to which the ordering process proceeds and the more marked is the increase in hardness. As experimental data were accumulated on 14-carat gold alloys, several contradictions arose. Certain observations tended to confirm the existence of a superstructure, while other observations seemed to be inconsistent with such a transformation. PRESENT INVESTIGATION As a focal point about which to develop this subject, it is expedient to consider first

Jan 1, 1943

The lead concentration of flotation feed ore slurries is determined using two ?-ray absorption gauges mounted directly on a 6 in. diameter flotation feed pipeline. One gauge is a conventional "density" gauge using CS137. The other is a "lead-sensitive" gauge, which depends on the preferential absorption. by lead of 225 key y-rays resulting from Compton backscatter of CS137 y-rays.Gauge outputs are combined using an analogue computer the output signal of which is directly proportional to the lead concentration of the pulp. The accuracy of measurement of the pulp lead concentration is ± 3·6 per cent for ore slurries with lead concentrations in the range 0'07-0·16 g/c.c. and pulp densities 1.43-1.60 g/c.c.This paper sets out the development of the technique and details are given of the two experiments (1964, 1966) conducted in the plant at North Broken Hill Limited. The installation of the two-gauge system inthe plant during May 1968 is described. Details are given of the calibration technique used and the results obtained.

Jan 1, 1969

By George S. Rice

[This paper gives the details of tests to determine the design of stoppings capable of withstanding a pressure, applied to either side, of 50 pounds per square inch,6 as required by section 104 (a) of the Operating Regulations to Govern Coal-Mining Methods on Leased Lands on the Public Domain, issued in 1921 and quoted oil page 3. The regulations stipulated that the design for such stoppings must lie approved by the United States Bureau of Standards. The engineers of that organization felt that knowledge of the strength of such structures with respect to the effect of explosion pressure in comparison with static pressure and the strength of the walls which furnish the abutments was insufficient to justify drafting specifications; therefore, tests were needed to give information upon which a rational system of design could be based. A study was then begun; and several series of tests, made by the United States Bureau of Mines and the United States Bureau of Standards in cooperation, grave information upon which are based the detailed specifications offered in a later section. Slabs representing concrete stoppings, with and without reinforcement, were tested at the Bureau of Standards in Washington D. C.; afterwards, full-scale stoppings were tested at the Bureau of Mines Experimental mine near Pittsburgh. It was assumed that in most coal mines the strength of the floor and roof could not be relied on, but dependence must be placed upon the strength of the coal ribs. The tests developed that the maximum strength of an unreinforced concrete stopping was obtained when it acted as a flat arch buttressed against the coil ribs; but its ultimate strength depended upon the resistance to movement offered by the coal strata against which its ends were restrained or buttressed.]

Jan 1, 1931

By S. H. Miller

Biodegradable hydraulic fluids can save tens or hundreds of thousands of dollars in fines and clean up costs in the event of a hydraulic fluid leak or spill. When properly selected, applied, maintained and monitored, a biodegradable fluid will have a long useful life and will protect equipment as well as or better than conventional petroleum based hydraulic fluids.

Jan 1, 2000

The Mount Lyell Mining Field is Australia's chief productive source of copper. It is situated near Queenstown, on the western flanks of the West Coast Ranges, about 20 miles from the west coast of Tasmania (Fig. 1).The following observations on the mineral composition of the copper ores of the Mount Lyell Field are based on a...

Jan 1, 1939

By Paul Zinner

Efforts to win an enriched manganiferous product from the Missouri Valley deposits of South Dakota have included an application of most known ore-dressing devices and have been largely unsuccessful. At least two methods showed some promise of success and were the subjects of detailed Investigation by the Bureau of Mines during the period from July 1945 to August 1947. A series of mining and beneficiation tests were undertaken to determine conditions under which the most feasible concentration methods could be employed and to define the limits of such applications in terms of the character of the final beneficiated product. In the absence of a significant current market for any conceivable product of beneficiation, the extent to which applied methods might be considered successful was measured in terms of ratios of recoveries to grade, regardless of the adaptability of such beneficiated products to further metallurgical or direct usage. The results of all investigations show that production of a shale-free, concretionary, manganese-bearing product by any known method requires great sacrifices in manganese recovery. Products of beneficiation, with specifications permitting some inclusion of shale, can probably be most effectively produced by methods employing specialized jigging equipment as the principal functional unit of a process.

Jan 1, 1949

By I. L. Nichols

The inplace cyanidation leaching of gold from placer deposits is a potential method for treating gravels too deeply buried and too low in gold content to be processed economically by conventional dredging methods. Laboratory experiments were made to evaluate those placer cyanidation factors adaptable to small-scale studies. The variables investigated included gold particle size and location in sand beds, cyanide solution flow rate, and cyanide solution strength as factors affecting gold solubility rates. The solution flow rate, in turn, was influenced by variables such as bed slope, solution head pressure, and sand size, and the effects of these factors were studied. Free gold, minus 150-mesh and finer in size, is rapidly dissolved by dilute cyanide solutions from mixtures of gold and silica sand prepared to simulate placer deposits. About 94 percent of minus 325-mesh free gold was extracted in 5 hours from silica sand mixtures, and 94 percent extraction of minus 150-mesh gold was obtained in 21 hours with 0.1 percent NaCN solutions. Moving solutions were almost twice as effective in leaching free gold from silica sand mixtures than stagnant solutions.

Jan 1, 1971

By M Dickie

During the 1980s and early 1990s low cost gold treatment plants were at the forefront of the Australian engineering and mineral processing business. This opportunity was the result of a high gold price and innovative design by emerging engineering companies in an expanding market. The low cost approach to gold plant design and project execution resulted in smaller and shorter life projects becoming viable and the multiplicity and fast track approach of the projects resulted in sharp learning curves. From the mid 1990s to the early 2000s the relatively low commodity prices and resultant reduction in minerals opportunities also resulted in innovative design in both small and large plants, albeit on a reduced scale. The innovation was associated with alleviating capital cost pressures for large capacity low-grade (eg NewcrestÆs Cadia) or small-scale (eg JubileeÆs Cosmos) projects to either improve NPV or to enable the project to be won and profitable in the competitive lump sum environment. Between 2004 and 2008 the engineering market became less competitive from an engineerÆs perspective due to the high demand for engineering services in a high price commodity market. The need for innovation remained but was driven overtly by shortages in water, power and personnel and long equipment lead times. This paper discusses some of the factors that contribute to the capital cost of a project and the scope for improving the likelihood of financing and increasing the project net present value (NPV). Case studies with recent large copper concentrator projects will be used to demonstrate how a value driven approach to project and plant layout can result in significant improvement in NPV.

Jan 1, 2009

By G. Richards

Research shows that having more women in the top mining jobs can bring bottom-line benefits. Mining companies are starting to embrace the need for greater gender diversity at board and senior management levels, figures and examples are given.

Jul 1, 2015

By David R. Mitchell, Ernest M. Spokes

There is evidence that study of minerals now considered to have susceptibilities too low for magnetic separation should be continued. Present concepts may be false. INFORMATION on magnetic properties of minerals other than magnetite is scanty and sometimes erroneous. Often there is no information at all. W. R. Crane's table of tractive forces published in 1901 is still the best guide in the field, but Crane's data can be used as a guide only, since he ignored such important factors as impurities in the minerals, size, and packing effect. During the 1930's work by the U. S. Bureau of Mines added greatly to knowledge of the behavior of certain minerals in a magnetic field. The USBM bulletin gave for the first time complete magnetic characteristics for magnetite and fragmentary data for a few other minerals. The work reported here covers a study of the magnetic-susceptibility relationships of the wolframite series of minerals and sphalerites as related to their chemical compositions. Theories are proposed to explain divergences found from commonly accepted beliefs. Gouy Method for Determining Magnetic Susceptibility: The Gouy principle has been adequately described in the literature1-3 and applied in various ways.'- It may be summarized by stating that a body of material (gas, liquid, solid, or powder mixed with gas or liquid) of cylindrical shape changes in apparent weight if suspended with one end in a zone of higher magnetic field strength than is found in that portion of the field surrounding the other end of the cylinder. This may be expressed as K2 - K1 A (H2 - H2) - mg. [1] In determining the susceptibility of mineral specimens by the Gouy method, the mineral is reduced to a fine powder and packed in a glass weighing tube. Precise measurement of the bore and depth of the tube is made unnecessary by a calibration procedure. Using the basic expression of Eq. 1, Hoare"

Jan 1, 1959

By David Preece

The Thirlmere aqueduct was constructed over 110 years ago to provide water from the Lake District (in the north-west of England) to the city of Manchester some 60 miles (100 km) away. The aqueduct remains, to this day, a key piece of infrastructure in the distribution of raw water in the north-west of England. A short section of the aqueduct was identified as being in poor condition during routine inspections by the owner. Subsequent investigations attributed the conduit damage to the movement of unstable ground over the conduit. Bachy Soletanche Ltd was subsequently appointed to carry out the design and construction of the slope stabilisation works and to undertake repairs inside the damaged conduit. The works were undertaken on an existing slope which, in places stands at a gradient of up to 40º to the horizontal. Strict limitations on plant and equipment were imposed by the client (United Utilities) to ensure that slope and conduit loading and associated vibrations were kept to an absolute minimum during construction. An intensive instrumentation system was installed to monitor surface movements, ground movements at depth, conduit movement and strains across existing planes of weaknesses within the conduit. The solution comprised the installation of spaced piles up-slope and down-slope of the conduit. Restrictions were imposed on the minimum stand-off distance between the outside face of the conduit and the piling works so targeted permeation grouting was undertaken to improve the ?connection? between the conduit and the down-slope piles. The presence of existing sub conduit groundwater flows was suspected and the permeation grouting was focused in areas to minimize disruption to the groundwater regime. The paper presents the basis of the design and highlights the combined construction and instrumentation methods adopted to minimise damage to this valuable asset.

Jan 1, 2011