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By K. N. Panigrahi

India bestowed with 6000km of the coastal belt, contains some of the richest and largest placer deposits with a mixture of heavy minerals like ilmenite, rutile, leucoxene, zircon, monazite, sillimanite and garnet. Each of the minerals is having economic value due to its inherent characteristics for industrial use in fields of paints, metallurgy, refractory, abrasive and so on. The reserves of titanium bearing minerals (ilmenite, leucoxene, and rutile) in the country is around 378 million tonnes. More than 90% of the titanium based minerals produced worldwide are utilised for making value added products in the pigment industries. Approximately 8 million tonnes of monazite reserves are available in the country from which several rare earth elements like cerium, neodymium, lanthanum, yttrium etc. can be extracted for use in several industries. The country contains a deposit of about 20 million tonnes of zircon, which is used in foundries, refractories, ceramics and chemicals. India has a reserve of 107 million tonnes of garnet and 131 million tonnes of sillimanite required for the abrasive and refractory industries respectively. Keeping in view the multifarious uses, the beach sand minerals are being exploited to have the economic growth of the nation. Although the process adopted for the separations are simple, the equipment involved are specially designed because of the nature of the material of construction. Starting from the spirals to magnetic separators, all equipments are manufactured outside India, which is not only costly, but the availability also takes much time for fulfilling the import formalities. Unlike open cast mining, beach sand mining is a environment friendly mining because dredging is implemented to cut and pump the loose sand through a slurry pump causing less damage to the surface topography as both mining and backfilling takes place simultaneously. Therefore all out efforts are made to explore the beach sand placer deposits in an economic manner to emerge as a leader in the global mineral industries.

Jan 1, 2005

By G. S. Camm

Gwynfynydd is a small, high-grade black shale-hosted vein-gold deposit. The Chidlaw Link Zone is the only area being mined and contains 24 000 t ore grading 15.2 g/t gold. Within the Link Zone a complex vein structure occurs consisting of a mother vein up to 5 m thick and narrow (less than 0.5 m) leader veins. The former shows minor variations in dip, strike and thickness, whereas the latter show marked changes in all three. The leader veins are hosted within the footwall zone of the mother vein and both are composed of quartz with galena, sphalerite, chalcopyrite, pyrite and minor arsenopyrite. The vein system is transected by a series of cross-vein and intra-vein dip-slip faults. Pockets of gold occur at vein intersections or branches and within the complex footwall zone and are often related to variations in vein attitude and/or geometry. The Chidlaw Link Zone displays a complex, erratic distribution of gold mineralisation and a multi-stage history of structural activity, fluid flow and mineral deposition

Jun 18, 1905

By A. R. Gaba

Phase I of the Canary Wharf development in London's docklands involves the construction of six fifteen storey buildings located predominantly over water of the West India Docks. The buildings are supported on some 1000 No., 25m long, open ended steel tubular piles driven through 10m of dock water to found in dense sand at a depth of about 15m below dock bed level. The piles are of composite section with reinforced concrete within the upper 17m of the steel tube. Three trial piles were installed in the dock to investigate the driveability and performance of the driven steel tubular piles. The piles were subjected to dynamic and static load testing. Loads were applied in both vertical and horizontal directions. Vibrating wire strain gauges were installed on the inside of the steel piles, on the reinforcement and in the concrete to determine the relative proportions of the applied load carried by the steel tube and concrete infill and to establish how these proportions varied along the length of the piles. Inclinometers were also installed to monitor the lateral deflection of the piles. This paper describes the driving, construction and testing of the three trial piles. The results of the vertical and horizontal loading tests are discussed and comparisons are made between dynamic and static tests carried out on the piles.

Jan 1, 1989

By D. L. Ogonowski, J. O. Marsden

The Candelaria copper-gold mine is located approximately 25 km south and east of Copiapo in Region III, Chile. The original concentrator was designed to treat 28,000 t/d (30,800 stpd) of chalcopyrite-bearing ore through a circuit consisting of a single 11.0 m(36 ft) diameter SAG mill, two ball mills, conventional rougher and scavenger flotation, column cell cleaner flotation, and ceramic disc filtration. The plant was commissioned in August 1994 and quickly reached design capacity and expected levels of metallurgical performance. In May 1996, a decision was made to double the capacity of the concentrator by the addition of a second line of equipment. The expanded facilities were commissioned in October 1997, less than 18 months after the decision to proceed, and well within the budget. The original concentrator facilities were replicated or duplicated as much as possible, however, a number of important equipment changes were made to take advantage of industry developments since the original concentrator was designed. These included the use of Eimco 120 m3 (4,200 ft3) cells for rougher and scavenger flotation and the installation of a Svedala VTM-800Vertimill for regrinding. This paper describes the rationale behind these changes and explores the reasons for the success of the project.

Jan 1, 1999

By D. Imeson, T. Grammatikopoulos, G. Pearse, M. Aghamirian, C. Mohns

"Spodumene mineral is a source of lithium for lithium ion batteries. Thus, the production of a spodumene concentrate with an approximate grade of 6% Li2O is targeted. Traditionally, spodumene is concentrated by froth flotation using fatty acid as the collector. Amine collector can also be used to float mica ahead of spodumene as required or feldspar from the spodumene tailings. Slimes have a negative effect on spodumene flotation and they are commonly separated by scrubbing and de-sliming prior to spodumene flotation. The main losses in spodumene flotation typically occur in cyclone overflow, scrubbing slimes, spodumene flotation tailings and mica concentrate. In recent years, dense media separation (DMS) is the main concentrating process in Australian spodumene operations. In these operations, DMS is efficient at generating coarse grain concentrates and rejecting large portions of silicate gangue, thereby directly reducing the milling cost. The ore should be crushed to 3/8” or coarser while further crushing is possibly necessary on the middling particles to scalp further spodumene. The DMS feed should be classified to remove fines (typically -0.5 mm particles). The final middlings and undersize fractions could then be processed by flotation. The main requirement in DMS operations is to have good spodumene liberation at relatively large grain size. This paper reviews the most significant DMS and flotation parameters in spodumene beneficiation. The treatments of different minerals in the spodumene ore are also addressed.INTRODUCTION A number of laboratory/pilot plant programs have been recently conducted at the SGS Lakefield site, sponsored by different clients. The main objective has been to develop a process flowsheet to generate a spodumene concentrate containing 6.0% or higher Li2O (~75% spodumene) suitable for producing lithium carbonate by a hydrometallurgical process. Depending on spodumene liberation size, dense media separation (DMS) can be an attractive option to produce a final high grade concentrate and to reduce the mass to be treated in the flotation circuit. In such a case, crushing would typically be performed in stages, with DMS separation to recover a spodumene concentrate and reject gangue minerals following each stage. DMS middlings and -0.5 mm fines can be processed by flotation to further recover spodumene. In the flotation process, coarse stage grinding minimizes the grinding cost and formation of slimes. In the majority of cases, a grind size (K80) of approximately 200 microns is sufficient for flotation. After primary grinding, mica, if present in an appreciable amount, should be floated to minimize interference with spodumene flotation. Desliming after scrubbing and high density conditioning are the key process operations prior to spodumene flotation. Spodumene can then be floated from silicate gangue minerals with a fatty acid or a mixture of fatty acid and petroleum sulfonate at slightly alkaline pH. Subsequently, feldspars can then be floated from the spodumene tailings."

Jan 1, 2012

By D. Chetty

The characterization of platinum group minerals (PGMs) from concentrator flotation circuits provides valuable information towards understanding PGM recovery under given milling and flotation conditions. Additional mineralogical characterization also provides information on ore variability, which may affect recovery. Considering the low grades involved, automated scanning electron microscopy (SEM) characterization of PGMs has enabled relatively quick analyses, compared with older, time consuming and less accurate optical microscopy methods. Over the years, parameters, such as species, size distribution, liberation, gangue and base metal sulfide (BMS) associations, have been used to characterize the PGMs in a process mineralogical context, to aid metallurgical interpretation. This paper considers whether flotation indices determined for PGMs can be empirically validated, using initial results from analysis of PGMs in a concentrate bank from a South African concentrator treating UG2 ore from the western limb of the Bushveld Complex. The aim is to determine whether floatability is adequately described by these parameters, or whether other mineralogical factors must be considered when assessing PGM floatability, and hence accounting for recovery vs. losses to tails. The data obtained to date, show that flotation parameters (including liberation index, BMS/gangue relationships and size distribution) have merits where large changes in PGM concentration occur, as observed in the first four cells of the concentrate bank. Larger data sets, however, are required to assess floatability, particularly where concentrate cell grades are similar, as observed in the last six cells of the concentrate bank. Furthermore, the floatability indices could be enhanced by the incorporation of selected associated gangue mineral information, chief amongst these being the content and mode of occurrence of naturally floatable talc and associated orthopyroxene.

Jan 1, 2009

By John G. Henning

The Porcupine Joint Venture operates the Dome Mine in South Porcupine, Ontario. Dome underground began production in 1910. It is the longest continuous operating gold mine in Canada, producing in excess of 15 M ounces. More than 900 underground stopes have been mined and hundreds of miles of drifts, sublevels and raises developed. Underground mining methods included shrinkage, cut and fill and longhole. Not all stopes were backfilled upon completion, particularly the longhole stopes. The Dome open pit was designed above the underground mine workings such that, as the pit is excavated, it intersects underground drifts and stopes. Potential operational problems associated with the interactions between the stopes and the pit walls may occur, necessitating pit wall redesign, ground support installation and operational rescheduling. Each intersection of the pit with the underground mine workings is closely evaluated to maintain a safe working environment and wall stability. This paper discussed how risks to pit wall stability are assessed, mitigated and monitored.

May 1, 2004

In considering the preparation of any paper concerning bearing metals, one feels a certain amount of diffidence in venturing into a field which has been capably explored at great length and in great detail during recent years. Many excellent articles have appeared in technical literature, dealing with the general theory of bearings and of bearing metals, the properties of white metals of the tin-base and lead-base types, and of the recently developed lead-bronzes.The justification for this further excursion into the field lies in the fact that it treats a branch of the bearing metal family which has so far received very little attention, and that of a somewhat sketchy nature, in published papers.The author's object is to give some outline of the history, development, present status and possibilities of the cadmium-base bearing metal alloys, particularly those in which copper is the main alloying element.GENERAL CONSIDERATIONS.It is desirable that attention should first of all be given to the general theory, constitution, and necessary attributes of bearing metals, in order that some of the problems met with during the development work may be better appreciated.Despite some evidence to the contrary, it is fairly generally maintained that an alloy for bearing metal use should be of a heterogeneous nature. It should consist of particles of a hard constituent uniformly distributed through a softer matrix.The basic idea is that the hard constituent should actually bear the load and resist wear, while the matrix imparts the necessary ductility and allows the bearing to align itself on the shaft in service.

Jan 1, 1934

By M. Matema

Paper written on project work carried out in partial fulfilment of BSc (Eng.) Metallurgy and Materials Engineering Small and large welded aluminium specimens were tested in fatigue and the results compared with design curves for aluminium in specification BS8118. Metallurgical tests were also performed on the specimens in order to correlate microscopic and macroscopic phenomena. The small-scale fatigue test results were in reasonable agreement with results in BS8118, whereas the large-scale fatigue tests showed that BS8118 is conservative.

Jan 1, 2005

By G. L. Oldright, J. D. Sullivan, W. E. Keck

"An apparatus and procedure developed in the laboratory of the South-west Experiment Station of the Bureau of Mines are capable not only of determining the rate and volume of penetration of solutions into porous materials but also of determining the total volume of voids within particles of porous material, and the density. The method is applicable to ores, bricks, concretes, tiles, filter bottoms, or other porous materials of this nature. As will be made clear in the descriptive matter to follow, the method measures (a) the volume of voids within the porous materials and is not concerned with the interstitial space between the particles.Porous materials usually contain some large voids and also pores that are capillary in nature. To measure the total volume of voids in a sample it is necessary to replace the gas or gases within the voids with some liquid of known density. The large cavities can be filled quite readily, but under ordinary conditions a long time may be required to fill capillary pores. As many porous materials are of a decomposable nature it is necessary to evacuate the porous materials and then submerge them in a liquid of known density to bring about saturation in a short time. Then by the use of a hydrostatic balance the volume of porous material (solid itself) can be determined. To determine the volume of porous material plus voids it is necessary to coat the sample with some material, such s paraffin, which will prevent solution from entering the voids; then, by means of a hydrostatic balance, the volume of porous material plus voids is determined and by subtracting that of the porous material from this the volume of voids is ascertained. The rate of penetration of solutions can be determined either (a) by measuring the change in weight as the sample becomes saturated when immersed ni a liquid of know density, or (b) by measuring the volume of liquid penetrating with a dilatometer. In either instance, due to the fact that some penetration takes place as soon as the sample comes in contact with solution and before a reading can be taken, the sample must be paraffined to determine the total volume of penetration. Since many porous materials partly decompose and disintegrate in liquids the rate and volume of penetration can better be measured by dilatometer than by the change in weight, as saturation takes place when immersed in a liquid. The details of procedure for determining (a) total volume of voids, and (b) rate and volume of penetration are given in this paper."

Oct 1, 1930

By Higgins RJ

Environmental investigations have been undertaken by Ok Tedi Mining Limited (OTML) since 1981 when the Ok Tedi Environmental Study was commenced. Environmental monit- oring and management programmes were implemented in 1983. The programmes included water quality monitoring, river flow and sediment monitoring, surveillance of aquatic biological communities and a health and nutrition survey of the local people. These original programmes have continued, and additional programmes of work have been developed and revised to reflect changing operations and the need to focus investigations on specific areas and issues of concern. In April 1990, following the establishment by the Government of Papua New Guinea (PNG) of environmental management criteria for the Fly River system, compliance monitoring programs were introduced. Details of the compliance and additional monitoring programmes undertaken by OTML throughout the Ok Tedi and Fly catchments, including programmes of investigation in the Fly River estuary, Gulf of Papua and Torres Strait, are presented.

Jan 1, 1991

By Leonardo Massone

The p-y method is one of the most popular methods in pile design and has been calibrated for various boundary conditions using numerical and experimental studies during recent years. Most studies on reinforced concrete (RC) piles have included the impact of flexural nonlinearity, (e.g. nonlinear moment?curvature relations) but not considered associated pile shear deformations when deriving p-y curves from field data. Common p-y curves may be better applicable for piles with flexure dominated failures (e.g. piles with free- head boundary conditions). For piles with fixed head boundaries (i.e. rotation restrained piles) shear deformations could be of significant influence. To study this problem, a coupled shear flexure interaction model for axial-bending-shear behavior coded in OpenSees was applied to a 0.61 m (2 ft) diameter flagpole and a 0.61m (2 ft) diameter fixed head pile specimen to investigate the possible influence of shear deformations to the overall pile responses. The surrounding soil was represented by p-y curves derived from prior large scale testing on piles with similar boundary conditions. Analysis results show that for flagpole piles, shear forces and shear deformations were insignificant. Considerable contributions of pile shear displacements and forces were observed for the fixed head pile, with shear displacements contributing up to 40% of the total pile displacement. Results suggest that nonlinear shear deformations for reinforced concrete piles should be considered for fixed-head or similar conditions, and that currently used p-y curves may underestimate the actual lateral pile displacement and possibly lead to unsafe design for the particular boundary condition.

Jan 1, 2012

By Richard S. Dennis

Acid recovery employs ion exchange (I-X) resin as separation media for inorganic acids from dissolved metallic salts by physical adsorption and without the use of chemicals. This technology has been used for years on spent etching and plating liquors to recover acid for reuse in the bath and to reduce waste acid neutralization costs. It is also used for electrolyte treatment to facilitate valuable metal recovery via acidity reduction. TETRA's ccrxr'" I-X contactor has been used successfully for acid separation from its metallic salt counterpart in a simple, continuous operating mode using strong base anion resins. Efficient separation is enhanced by acid reconcentration to nearly its original strength or as high as 14-20%. Continuous treatment also recovers heat to the tankhouse or bath and improves metal quality due to consistent acid quality. Conventional fixed bed ion exchange (I-X) systems are impractical for acid recovery because of complex control design and large resin inventories needed to process very low liquid-to-resin treatment ratios associated with strong acid concentrations.

Jan 1, 1996

By H. R. Shell

Fluorphlogopite mica was synthesized from inexpensive and abundant olivine, clay, feldspar, and sand (plus K2SiF6). The raw materials were melted in crucibles and in an internal resistance electric furnace. The melts yielded >95 percent mica. The major difficulty encountered was incomplete settling of the highly dispersed ferroalloy. This problem was not completely solved. Reducing agents tried in melts of 300 to 400 pounds were carbon, silicon, and silicon carbide. Carbon slowly reduced the iron of the raw materials, with much fuming. Silicon apparently was oxidized ahead of the melting and was ineffective under the conditions obtained. By far the best reducing agent was silicon carbide. With silicon carbide, fuming did not occur and ionic iron content of the mica flake approached 0 percent. However, even with SiC, the highly dispersed globular iron did not completely separate from the mica portion. The fluorphlogopite made during this investigation should be suitable for metallurgical use. A byproduct ferroalloy containing about 5 percent nickel, 3 to 5 percent chromium, and some cobalt was obtained. Because of the highly dispersed metallic ferroalloy, the mica was not deemed suitable for electrical or electronic uses.

Jan 1, 1962

Recent improvements are described in several techniques for ground control in underground mining. Promising methods for analysis and mitigation of rockbursts are discussed. Methods of assessing damage to underground excavations from repetitive seismic loading are reviewed. Analysis of mining-induced surface subsidence is discussed.

Jan 1, 1989

The Anshan Iron and Steel Co. (AISC) broke its steelmaking design capacity in 1978, bringing its total production of steel products to 6.86 Mt. Located south of the industrial city of Shenyang, Liaoning Province, in northeastern China, it is by far China’s most important iron and steel complex, ranking twentieth among world centers. The complex represents a unique blend of old ecluipment and new ideas for increased production and improved products. Under a state plan, the Chinese hope to raise capacity to almost 15 Mt/a in the future. Originally started by the Japanese in the early 1920s, Anshan has had a rather turbulent 60-year history. It was disassembled by the Soviets after World War II, only to be reassembled by them in the 1950s. Production was also suppressed during the Cultural Revolution. Since the present-day organization, AISC, emerged, the center has experienced progressively improving conditions as well as increased production. Today, the center includes 10 blast furnaces, 24 open hearths, and two basic oxygen units, designed for 7 Mt/a ironmaking and 6.5 Mt/a steelmaking. In addition, it has six batteries of cokemaking facilities with combined 4.4-Mt/a capacity. Solid Iron Resources Anshan’s iron resources consist of a proven reserve base of over 7 Gt of 30~0 Fe, according to Kao Yang, president of the Anshan Iron Mining Co., a subsidiary of AI SC, Most of that, he continued, is amenable to surface mining. Five major mines located to the north and northeast of the city of Anshan are the principal iron ore producers. These mines trend in a somewhat circular manner and combined, represent an estimated 28.6 Ylt/a of ore capacity. In addition, some 2.2 Gt of magnesite, a necessary ingredient in steelmaking, are also part of the reserve base, according to Kao. Annual production is around .2 Mt/a of 47% magnesite, well over the steelmaking center’s annual requirements, Excess production is shipped to other steel-making centers. The largest of Anshau’s open-pit mines is the Chitashan operation with a design capacity of 8 Mt/a. Ore reserves here are well over a billion tons of 30% Fe. Earlier plans to expand production at this mine to 15 Mt/a, with the help of US Steel, have been temporarily shelved. The other mines in the district and their rated design capacity are: Kungchangling, 7 Mt/a; Donganshan, 6.4 Mt/a; Dakushan, 4.2 Mt/ti; and Yenchienshan, 3.0 Mt/a. The Kungchangling mine is the richest in terms of ore grade at 6076 Fe. Reserves are somewhat smaller at 100 Mt. The unit also operates a small shrinkage stoping operation. Ore grade at the other mines is usually 30-327. Fe. Llost mines operated at reduced capacity during 1979 owing to a natural gas shortage at the mills. The general

Jan 3, 1980

By William Babcock

Augered, Cast-In-Place (ACIP) piles can be an economical, reliable, versatile foundation system. They have also been a part of projects that were behind schedule and the subject of lawsuits. The ACIP pile is a specialty system that is more workmanship dependent than most deep foundation systems and is especially vulnerable to the problems and abuse of poor specifications and contract language. Many of the original specifications were based on grouting methods, and numerous misconceptions have followed the method. The Deep Foundations Institute (DFI) has been the leader in debunking the mystique that has hovered over the method and attempted to standardize the industry through publication of the manuals describing the method and how it should be inspected. DFI should be applauded for taking the lead and producing a reference document that can be used to educate the specification writers, designers, inspectors, and owners. It must be must appreciated that there have been other organizations that would not acknowledge ACIP piles as a legitimate member of the deep foundation family. Some consultants and designers have gone to the extreme of making it policy to not recommend the method for use. This presentation is one practitioner's view of the causes of problems as they can be traced back to the contractual conditions. It is intended to provide a broader and different perspective than those provided by the technical specialists. It does not necessarily reflect the position of the DFI or any of the organizations associated with the ACIP pile industry. It is intended to further the spirit of partnering on every ACIP pile project, to further the acceptance and promote the use of this unique system, for the benefit of all the parties. It should be recognized, however, that all of the participants can and do play a role in getting a project into trouble. My view is that projects that get into trouble usually have an early flaw that leads the project to the edge, and the project participants blindly follow the original mistake right over the cliff like lemmings. This instinctive reaction may be a survival tactic by going along with the group, because any one party that departs from the program or shows a position of weakness is a candidate for sacrifice.

Jan 1, 1997

Notwithstanding full concurrence with the dictum of a famous scientist that "definitions are the most accursed of all things on the face of the earth," in view of the considerable confusion which exists in jigging nomenclature, it is considered advisable to commence this paper with the following explanations of the terms which will be used throughout the text.Jig Bed. The whole layer of material lying on top of the jig screen.Ragging. The layer of denser material lying immediately above the jig screen, which is too coarse to pass through this screen and is confined horizontally by the cells of the top grid.Ore Column. The layer of ore pulp between the ragging and the top-water.Top Water. The water, carrying fine material in suspension, which flOiWS over the surface of the jig bed.Hutch Water. The water added to the jig below the screen. (Except for the water discharged with the hutch concentrate, the "hutch-water" eventually becomes "top-water.")Feed Water. The water in the ore pulp fed to the jig.(This water becomes part of the "top-water.")Pulsion. The period of the jigging cycle during which the water is moving upwards relative to the particles in the jig bed.

Jan 1, 1937

By B. R. Stewart, L. W. Zelazny

The exclusion of coal fly ash from regulation as a hazardous waste has led to increased interest in returning ash to the coalfields for co-disposal. A multi-year column study used coal refuse with high potential acidity (4% total-S), and two alkaline ashes in various bulk-blends. The unamended refuse acidified rapidly, producing acidic (pH 1.7) leachates, high in dissolved metals. Treatments blended with sufficiently high amounts (20 to 33%) of alkaline ash produced alkaline (pH >8.4) leachates with low metal levels, while lower ash blending rates acidified over time to produce metalliferous leachates. Examination of solid materials indicated that pyrite oxidation was occurring to some extent in all treatments. A regression equation (r2 = 0.95) was developed to estimate time to net acid release for mixtures of these materials. Ash alkalinity and refuse potential acidity must be balanced to insure water quality for co-disposal environments, or the ash materials should be isolated away from acidic drainage waters.

Feb 24, 1997

By W. Greg Maybee

Separations, which form along stratigraphic boundaries in the roofs of potash mines, pose a serious safety concern. If these separations go undetected they can lead to falls of ground. The current method of identifying the location and extent of these separations is through manual scaling (sounding) using an aluminium rod. The potash mining companies would like to have a tool, which could quickly and reliably detect these separations and distinguish between them and clay seams. This paper presents the results of field trials undertaken at various potash mines in Saskatchewan belonging to the member companies of the Saskatchewan Potash Producers Association. A ground penetrating radar instrument from RST called SUSI (stepped frequency, ultra-wideband, synthetic aperture radar instrument) was used. SUSI has the ability of working over various frequency bandwidths. Four mines were chosen for these field trials, covering the different geological characteristics encountered in the Saskatchewan potash mines: Potash Corporation of Saskatchewan?s (PCS) Allan and Lanigan Divisions, Agrium?s Vanscoy Potash Operations and IMC Potash?s K2 Mine. These field trials indicated that stepped frequency ground penetrating radar technology could be ?tuned? to identify both separations and clay stratigraphy in the softrock, potash mine environment, based on the different spectral responses of the features.

May 1, 2004