Search Documents

By Thomas J. Ferree

"IntroductionThe objective of this chapter is to provide important criteria relating to the operation and maintenance of spiral concentrators and Reichert cones, so that optimum performance can be achieved and maintained in a mill circuit. Little space will be devoted to the theory of the forces of separation or the technical details of the devices, as that in(ormation is available from other sources. The discussions in this chapter will be presented in a manner that should be interesting and useful to anyone who may be exposed to these methods of gravity separation. It is most important for the reader to understand that each application of the equipment should be considered on its own merit, as no two suites of minerals respond exactly alike in mineral processing circuits. The information herein should be useful as a guide toward increasing the metallurgical efficiency of the processes, irrespective of the type of minerals being concentrated.It is highly recommended that certain tools be made available to the personnel responsible for metallurgical performance of the spirals and cones; these include a set of standard type laboratory screens, a medium quality petrographic microscope, and a vanning plaque or gold pan. These devices, when used in conjunction with a basic understanding of the mill circuit, provide immediate knowledge on the characteristics of any sample in the mill circuit. The information gained by visual evaluation of sized fractions of products can solve many of the basic problems of mineral beneficiation, and at the same time increase the interest of the non-technical personnel associated with the plant operation. There are many problems associated with obtaining satisfactory performance from a mill operation. Many of the problems have to be solved using a technical approach. Some of the problems, however, can be solved with practical knowledge and common sense. It is hoped this chapter can provide a guide to both techniques."

Jan 1, 1989

By W. R. Hudspeth

AS an outgrowth of its spodumene recovery operation at Kings Mountain, N. C., Foote Mineral Co. has been recovering a heavy mineral by-product. Foote leased this idle plant in 1951, reactivated it, using a new spodumene recovery process, and purchased plant and properties in October 1951. While the operation at Kings Mountain is primarily concerned with the production of spodumene concentrate, pilot plant work determined that the pegmatites also contained heavy minerals including cassiterite. Plans were made to recover the heavy minerals as a by-product and the flowsheet incorporated these facilities when the mill was modified for the new spodumene recovery process. The orebodies consist of spodumene, feldspar, quartz and mica. Apatite, tourmaline, and beryl are present in small quantities. The wall rock is pre- dominantly hornblende shist. The heavy minerals, including cassiterite, columbite, pyrrhotite, monazite, pyrite, and rutile represent about 0.2 pct of the ore. The fine-grained heavy minerals are disseminated throughout the dikes, apparently unassociated with the spodumene. The pegmatites are quarried and secondary breakage is by mud-capping and block-holing. Power shovels load into trucks transporting the ore to a coarse ore bin. A Telesmith 10x36-in. apron feeder delivers the ore to an 18x36 in. Traylor Jaw crusher adjusted to discharge -3 in. product to a primary conveyor. The conveyor delivers to a 4x5-ft Tyrock single deck vibrating screen using 3/4 in. cloth. The screen undersize is elevated to the crushed ore bin. Screen oversize goes to an Allis-Chalmers Hydrocone Crusher fitted with 4 in. concave and set to deliver approximately 66 pct minus 3/4 in. The crusher discharge returns to the primary conveyor. The crushing and screening installation has a capacity of about 60 tons per hour. Spirals The crushed ore is delivered at a rate of 350 tons per day to two 6x8-ft Hardinge Pebble Mills, equipped with 20 mesh Ton-Cap trommel screens. The screen oversize is pumped to a 12-in. hydroclone for primary desliming. The hydroclone underfl spirals. There is no heavy mineral loss in the hydro-clone overflow. The spirals bank consists of eight 5-turn Model 24-A Humphreys Spirals. The top port and the last four ports of each spiral are blanked, the remaining nine port splitters are adjusted to remove about 5 pct feed weight. The heavy mineral rougher concentrates are upgraded on a Deister Overstrom table. The spiral concentrates contain approximately 4 pct heavy mineral, and the spiral reject, which goes to another section of the plant for spodumene recovery, contains about 0.03 pct heavy mineral. There is an interesting feature in the spirals installation. An adjustable splitter mounted on the discharge boxes splits out a mica fines product containing very little heavy mineral. The mica product is cleaned by spiralling and screening. Thus the spirals recover two products; mica, and a heavy mineral rougher concentrate. Table Treatment The rougher spiral concentrate goes to a Deister Plato table, modified to receive a Deister-Overstrom No. 6 rubber cover with sand riffles. The table is operated with a 5/8 in. stroke, 270 strokes per minute, and a slope of 1/2 in. per ft from feed to tailings side. There is no slope adjustment from motion to concentrate end. Wash water consumption is relatively high, since the large spodumene grains tend to report with the fine heavy minerals. A middling band about 4 in. wide is maintained in order to produce clean concentrate. The middling, representing about 10 pct of table feed, is recirculated by air-lift. A band of concentrate grade coarse spodumene occurs just below the middling. This is removed and delivered to concentrate storage. The table tailing, containing approximately 0.7 pct heavy minerals, is returned to the spodumene feed preparation circuit. The heavy mineral table concentrates are approximately 45 pct cassiterite, 33 pct columbite, 14 pct pyrrhotite and 8 pct monazite, together, with some rutile, pyrite, and copper from blasting wire. Concentrate is collected at 24 hour intervals. and dried. If the concentrate remains in wet storage appreciably longer surface oxidation takes place which seriously interferes with the subsequent magnetic separation process. About 150 lb of heavy mineral concentrate is produced per 24 hours and shipped to the company's plant at Exton, Pa. for final separation into tin and columbium concentrates.

Jan 1, 1952

By P. C. Kapur

For mineral processing spirals, mathematical force equilibrium models are sought to extend the spiral performance envelop. In Part 1 of this report, a complete geometric description of the helical spiral and its trough or channel contour is provided. The secondary circulatory fluid motion in the transverse direction that develops when water flows down a tightly turning curvilinear path and its implications for gravity separation are discussed. Different forces that act on the particle during its passage through the spiral are enumerated and quantified for a better appreciation of their relative contributions and roles in the separation process. Three force equilibrium models from the hydrology literature on sed iment transport are employed to simulate a typical spiral. While the results are promising in that the models mimic the broad performance characteristics of the spiral, what is needed is a more general spiral model taking explicit cognizance of the missing components essential to the spiral description. These are such components as centrifugal force and the steep tangential slope of the channel deck. Results of this latter exercise are deferred to Part 2.

Jan 1, 1996

By Odmund Ljone

FAR north of the Arctic Circle is a totally industrial community which until 1945 could not boast a single specimen of the rat family, and where today you will be awarded a bottle of fine cognac for every rat-dead or alive. Amazing but true, the spot is Longyear City, the Norwegian mining town on the arctic island of Spitzbergen. Perhaps you have also heard of the town built on soil that never thaws, where huge blocks of ice must be melted to fill the city's fresh water reservoirs, and where the Far North dictates a way of life all its own. Here, coal is king and men must work hard for their "black gold." Spitzbergen is a rough, tough piece of Norway, made up of a half dozen isolated islands between 74 and 81 degrees north latitude. Covering twice the area of Belgium, they are home to

Jan 1, 1948

By K. Mansfield

Spent Pot Lining (SPL) is an unavoidable waste product of the electrolytic process in the smelting of aluminium. SPL is considered to be a hazardous waste in various countries because it contains significant quantities of absorbed fluorides along with traces of cyanide. In 1995, Portland Aluminium undertook the investment of AUD$26,400,000 to construct a Research and Development processing facility at Portland, Victoria, Australia, to treat SPL. Extensive research, development and design were carried out over 5 years prior to the investment decision. This study led Portland Aluminium to install an Ausmelt pyrometallurgical furnace to combust and melt the SPL producing a hydrogen fluoride (HF) laden gas, which was cooled and then converted to aluminium fluoride (AlF3). Both the cooling and AIF3 manufacture were processes developed by Portland Aluminium. Many commissioning, equipment reliability and process problems have been encountered that had not been experienced in the trials at Ausmelt or in the developmental process for the treatment of the furnace offgases to form AlF3. Designs based on anticipated process expectations have had to be re-engineered by the SPL team to ensure plant and operational success. In June 2001, the installation of the final major component - a slag granulation process - was completed. This has produced a vitrified (glassy) slag that is expected to have leachability qualities acceptable to the Victorian Environment Protection Authority (EPA) to allow commercial end uses of the slag material to be developed. Today (September 2001), the smelter has successfully used the fluoride product, namely 65- 70% AIF3, in aluminium production and the SPL plant has significantly increased throughput with expectations to be at annual design rates of 12,000 tonne of SPL in early 2002. "The Alcoa Portland SPL Process" has been technically developed and is a proven process for the treatment and recovery of valuable components from SPL materials.

Jan 1, 2002

Splashing and wave formation has been studied experimentally by using one-seventh water model of CLU (Creusot-Loire Uddeholm) reactor with two different tuyere configurations by using paraffin and water as simulated slag and simulated metal respectively. Experimental results have been discussed in terms of total splash volume, relative slag volume in splash (dispersed-slag phase holdup in splash), wave frequency and wave amplitude with respect to gas injection rate and tuyere configuration at bath heights between 0.25m and 0.38m. Gas flow rates ranged from 0.00599m3/s to 0.01312 m3/s. The results of splash measurements showed that splash volume increased with increasing gas flow rate and decreasing bath heights for both tuyere arrangements. However, off-centre configuration resulted in relatively higher amounts of splash. The slag volume in splash (Dph in splash) was also found to increase with decreasing bath heights and increasing gas injection rates. The high speed photography revealed that the frequency and wave amplitude increased with gas injection rate. The experimental results also showed that the frequency and vertical displacement of the rotating wave increased when the tuyere orientation became off-centered. This might be used to explain why off-center configuration resulted in generating higher splash volumes than the center configuration.

Jan 1, 2004

By Courtney Young, Jerome Downey

"The various technologies developed for treating spent potlining (SPL) from primary aluminum smelters have been reviewed on several occasions. The technologies generally involve physical, chemical, and thermal processes, either individually or in combination, with the primary objective of total recycle, waste minimization, or complete disposal. In general, those technologies geared for recycling involve separations and are therefore subject to recovery inefficiencies that are attributed to several factors. However, the inefficiencies could be reduced or possibly eliminated if the pots were designed for recyclability. This concept is applied to SPLASH, a recently developed SPL management technology.IntroductionAluminum is produced by molten salt electrolysis via the Hall-Héroult process. The process is conducted in an electrolytic “pot,” which is comprised of a steel frame first lined with insulating refractory brick, and then conductive graphite blocks, which serves as the carbon cathode [1, 2]. These materials are collectively referred to as “potlining.” Anodes comprised of petroleum coke/pitch are suspended above the pot and extend down into the molten cryolite (Na3AlF6) electrolyte. The electrolyte temperature is maintained at approximately 980 °C by resistance heating as low voltage (4-5 volts) and high current (50,000-300,000 amps) are applied across the two electrodes.High purity alumina is added to the cryolite bath, where it dissolves and becomes amenable to aluminum reduction at the cathode:"

Jan 1, 2008

By T. Gerritsen, C. Martinez, F. Stober, T Ma, J. R. Frias, M. Sedighy, J. Janzen

Electrode control systems regulate power by physically positioning electrodes. Due to the weight and inertia of the electrodes and hoist equipment, this is a relatively slow process where power fluctuations of less than a few seconds are not fully corrected. Nickel laterite AC furnaces operating in high voltage, shielded arc mode typically incur frequent power variations of approximately +/- 20% or more around the power set point. To provide enhanced power control, Hatch has recently supplied, at commercial scale, a thyristor-switched reactance system called an SPLC. The SPLC incorporates predictive control software to operate furnaces at the maximum transformer rating by reducing the large power swings experienced without the SPLC. The resulting higher average power enables higher production, without increasing transformer or power plant capacity. A 60 MW production version of the SPLC has been commissioned on Falconbridge Dominicana's laterite nickel furnace, yielding excellent results with a 3 to 1 reduction in power fluctuations.

Jan 1, 2005

By Terry Gerritsen

Electrode control systems regulate power by physically positioning electrodes. Due to the size and weight of the electrodes, this is a slow process where power fluctuations of less than a few seconds are not fully corrected. Nickel laterite AC furnaces operating in high voltage, shielded arc mode typically incur frequent power variations of approximately +I- 20% around the power set point. To provide enhanced power control, Hatch has recently supplied, at commercial scale, a thyristor-switched reactance system called an SPLC. The SPLC incorporates predictive control software to operate furnaces at the maximum transformer rating by reducing the large power swings experienced without the SPLC. The resulting higher average power enables higher production, without increasing transformer or power plant capacity. A 60 MW production version of the SPLC has been commissioned on Falconbridge Dominicans's laterite nickel furnace, yielding excellent results with a 3 to I reduction in power fluctuations. Keywords: SPLC, AC Power Supply, Electric Furnace

Jan 1, 2004

By Shobhana Dey

A low volatile medium coking coal from Jharia coal field, India was used for this investigation. The proximate analysis of the sample shows that it contains about 25% ash, 21.4% volatile matter and 52.4% fixed carbon. The sizewise ash analysis of -0.5 mm coal indicates that -0.5+0.15 mm fraction contains lower ash (21.9%) than -0.15 mm fraction (29.7%). The flotation characteristics of the -0.5 mm coal were determined by release analysis. The study reveals that recovery of combustible at 15% ash is about 27% and 43% at 17% ash level. The low recovery is due to the presence of high ash in finer fraction. In order to improve the recovery, the -0.5 mm feed was classified into -0.5+0.15 mm and -0.15 mm fractions, and subjected to flotation separately. The recoverable combustible obtained from the release analysis of -0.5+0.15 mm at 15% ash level is 46%. The effect of collector dosage, frother dosage and aeration rate on flotation was studied. The responses of these variables in collectorless flotation of the -0.5+0.15 mm fraction containing low ash were also studied. A lower aeration and frother dosage favored the generation of clean coal with low ash. The ash content in the tailing stream from -0.5+0.15 mm flotation circuit is close to that of the original -0.15 mm fraction. The former is ground to -0.15 mm and the two fractions are processed together. As -0.15 mm fraction contains relatively higher ash, collector aided flotation using sodium silicate was performed to recover the clean coal with 17% ash. The products of the overall flotation circuit having different ash levels were recommended for use in different applications. The reject from -0.15 mm flotation circuit contained 56.4% ash which can be used for fluidized bed combustion (FBC). This eventually leads to complete utilization of coal.

Sep 1, 2012

In today?s high tech world, systems are getting bigger, faster, better. To remain at the leading edge, in any business, depends on accurate but flexible design thereby allowing operational managers to provide alternatives to improve their operations. The ultimate goal is to deliver to plan, with optimum economics. Mining is no different, with falling prices and escalating costs, improved margins become the focal objective. There are many ways to achieve this, ranging from operational efficiency improvements through production scenarios to planning initiatives. Of all, planning usually receives the least attention, yet it is the area of most influence on the NPV of the reserve. With computer technology, numerous concepts and iterations are possible thereby closing the gap between optimal and actual design. This paper discusses the application of the split shell design at the De Beers Venetia open pit in South Africa.

Jan 1, 2001

By John A. Herbst, Gerald H. Luttrell, Jaisen N. Kohmuench, Aaron Noble, Michael J. Mankosa

The HydroFloat TM is an innovative fluidized-bed separator that can substantially increase the upper particle size that can be successfully treated by flotation. Recent studies conducted using laboratory, bench-scale and pilot-scale equipment indicate that this technology can be used to float coarse sulfide middlings that cannot be recovered by conventional flotation machines. Recent data collected from pilotscale tests conducted at a base metal concentrator indicate that this technology can float middlings particles as large as 850 microns in diameter containing as little as 1% exposed hydrophobic mineral. As such, the crossover of this technology into the base metals industry has the potential to substantially reduce grinding costs and increase concentrator recovery/capacity through the use of split-feed circuitry. The split-feed concept, which is often used for upgrading industrial minerals, involves segregation of the feed into more than one size class followed by subsequent upgrading using mills/separators/reagents specifically optimized for each size class. In this article, a split-feed circuit is described that utilizes two stages of classifying cyclones in conjunction with the HydroFloat_ separator. The circuit is designed to recover, recycle and regrind coarse middlings containing small amounts of valuable mineral while simultaneously rejecting coarse well-liberated siliceous gangue so that mill throughput can be increased. Simulation data conducted using well-known process models suggest that this approach can increase existing primary mill capacity by up to 25% with only modest investments in new classifying and flotation equipment.

Jan 1, 2016

By J. Kemeny, B. Norton, T. W. BoBo

Digital image analysis systems to quantify particle size of crushed materials have successfully been applied in large-scale mining operations throughout the world. Particle size measurement at various crushing and sieving stages, especially in aggregate production, will facilitate the industry’s desire and need to achieve higher levels of process control and automation. This paper will 1) summarize applications of digital image analysis in the industrial minerals industries and introduce the Split-Online technology; 2) detail an actual recent test application of digital image analysis that ultimately lead to the installation of an automatic, non-invasive particle size distribution monitoring system; 3) document how this information is being applied: and 4) summarize the new Split-Online Aggregates Module now available.

Jan 1, 2004

By G Dean Barrett

Just one year ago at the 1986 Annual Meeting of the Society of Explosives Engineers, Dr. Calvin J. Konya presented a paper entitled "Presplitting Granite Using Pyrodex, A Propellant.'' Since that time more evidence has been developed to support the concept that "...gas energy can be the principal splitting force and that the stress wave or shock wave is not necessary to cause the presplitting action to occur." Work done in Vermont and Georgia is presented, and the ability to split granite without causing radial cracking of the bore holes is demonstrated.

Jan 1, 1987

By A. Brian Hawkins

"When pyrite oxidizes in dark grey/black, calcareous, mudrocks or in argillaceous limestones, ferrous sulfate is formed and sulfuric acid is released. The sulfuric acid combines with the calcite present in the rock and calcium sulfate (gypsum) develops. When this occurs on the outer edges of aggregate particles, the gypsum forms in the matrix hence there may be little expansion of the general material. However, when the chemical reactions occur within the rock fragments, particularly on microscopic, clayrich, laminae, the developing crystals exert a significant pressure on the host material. If the rock is medium strong to strong, the force of crystallization splits the rock along the weaker planes, facilitating the ingress of the oxidizing agents and the continuation of the chemical reactions. In addition to causing dilation/heave, some of the engineering properties of the material are changed, including the strength, Los Angeles value, water absorption etc. As a consequence material, which at the time of quarrying would be acceptable for use beneath floors or hardstandings, would no longer be considered suitable.INTRODUCTIONMudrocks accreting in aerobic environments are frequently disturbed by organisms and as a consequence there is often little sign of bedding. In contrast, sediments which have formed in anoxic environments commonly have distinct bedding planes which, because of the grain size of the accreting material, are often smooth and planar. These rocks are frequently referred to as shales, which O’Brien and Slatt (1990) define as “characterised by a finely laminated structure, which imparts a fissility approximately parallel to the bedding.” This should not be confused with rhythmic bedding where the variation in grain size results in lithological laminations or colour changes.Early geologists, in the stratigraphic naming of rocks, often used the term shale for material which is now more likely to be described as mudstone or mudrock (Hawkins and Pinches, 1992). In many contexts, the width of the bedding is an important factor, not only in determining the rock name but also in indicating the potential engineering characteristics. Until recently a shale was considered to have bedding separations of less than 20mm, i.e. the bedding was described as laminated. However, in an engineering context, EN 14689: 2003, Annex A, defines shale by specifying a bedding thickness of < 6mm; such a material would be described as thinly laminated in BS 5930:1999. Ideally the term shale should be abandoned and be replaced by fissile mudstone or fissile mudrock."

Jan 1, 2015

By H. E. T. Haultain

I HAVE considerable hesitation in preparing and presenting this paper. These machines have been such an intimate part of my own experiences and predilections for such a long time that J would find it difficult to tell the story in an impersonal way. They have had several attractions for me. They were needed for the study of the fundamental features of modern milling, size analysis and accurate batch concentration of the very fine particles. I had been a millman once, a real operating millman, and, when I became academic". I always had the craving to link the academic laboratory with the field, as Rittinger and Richards had done. My first milling experience was with a small concentrator at a tin mine in Bohemia, forty-seven years ago. There was no assay office and the testing of our tailings was by means of a "Vanning Shovel", introduced from Cornwall by Captain Josiah Thomas, the great Josiah of Dolcoath, some fifteen years previously. This was a most effective instrument and it has always been a puzzle to me that it has not been more universally used by millmen. Later, at Freiberg, on the other side of the Erz Gebirge from the tin mine, I was introduced to the "Sichertrog", made out of wood shaped something like a very shallow boat or an elongated saucer, a most effective piece of apparatus when. the difficult technique of handling it was once achieved. Later, in the Slocan in British Columbia, my partner, the late Maurice Bucke, used a short length of flat trough or launder suspended by four wires, with which he got very satisfactory results as a small batch concentrator. In the University laboratory we had frequent need for something of this kind, and many efforts were made to solve the problem. With W. E. Johnston, we were working on the problem of gold-bearing telluride ores, which called insistently for a separation of the very fine telluride particles which existed only in minute quantities in the Kirkland Lake ores. Under this spur there finally developed the Superpanner, which is a mechanized combination of the Vanning Shovel, the Sichertrog, and the Maurice Bucke suspended launder.

Jan 1, 1937

By R. F. Pilgrim

"This first chapter of the SPOC Manual 1s intended as a general introduction to all the other chapters in which the mineral process evaluation and optimization methodology is presented. This chapter also provides a brief description of available software for mainframe and m1crocomputers and provides information on its distribution by the Technology Information Division. CANMETRESUMECe premier chapitre du manuel SPOC est un guide général qui présente les autres chapitres ou l'on traite de la méthodologie d'évaluation et d'optimisation des procédés miméralurgiques. Le lecteur y trouvera aussi une description sommaire des programmes de calcul développés pour ordinateurs centraux et pour micro-ordinateurs ainsi que la façon de les obtenir de la Division de l'information technologique du CANMETComputer simulation of mineral processes has slowly emerged as an established branch of activity in A&D centres and in several teaching institutions after decades of slow progress. Substantial efforts to develop application software based on years of research on process modelling are being pursued in many countries ( 1 .2,3,4.5). The late BO's should see a flurry of success stones about significant leaps of productivity achieved in several plants through systematic process evaluation and computer simulation studies.In Canada. the SPOC project (Simulated Processrng of Ore and Coal) was initiated at CAN MET in 1980 with the obJective of developing and transferrrng to the mineral rndustry a computer-based methodology for process evaluation and optimization. The proiect deliverables include:- an engineering manual covering most aspects of off-line computer simulation:- a bank of FORTRAN software accessible through data communication lines for user familiarization and distributed at a nominal cost in source form by CANMETThe yearly progress reports of the project contain detailed information on the project elements since 1980 16). The context of SPOC can be summed up by quoting Gordon Agar""s 1975 statement during a workshop on research needs in the mineral industry: ""What is needed is a joint effort between the academic community and one or more enliglitened industrial concerns. The effort will have to be an iterative one with data collection followed by testing the model modification of the model (s), more testing prediction, modification. data collection and so on (7). A few parallel in1- t1atives had been reported in papers or research contract reports (8, 9) but there was an obvious need for CANMET to bridge the gap between the R&D and the production sectors by undertaking a project that would document past applications and induce a new generation of initiatives through the consol1dat1on and transfer of suitable manuals and software. The effort took shape as the CANMET SPOC pro1ect in which methodology transfer was to play a key role (10)."

Jan 1, 1986

By J. Flemming, R. O. Burt

"The Tanco pegmatite is located in the Bird River greenstone belt of southeastern Manitoba approximately 160 km northeast of Winnipeg (Figure 1). This pegmatite body was discovered in 1929 and subsequently attempts were made to exploit it for tin by Jack Nutt Mines Ltd. and later in the middle 1950's by Montgary Oil Ltd., who extensively developed but did not produce from, its lithium deposits. In 1966 systematic investigation of the pegmatite as a potential source of tantalum led to the founding of Tantalum Mining Corporation of Canada Ltd. (TANGO) in 1967 and production of tantalum concentrates from the Bernie Lake mine commenced in 1969. Tanco is currently jointly owned by Hudson Bay Mining and Smelting Co., Cabot Beryl co Inc. of Boston, and the Province of Manitoba. (Williams and others 1978, Burt 1979, Burt and others 1982), continued until the end of 1982, when, due to falling demand and prices, operations were suspended.During the 1970's Tanco had investigated the potential of the lithium orebody; carrying our research into both the concentration of the ore and into the production of lithium chemicals. However lithium chemicals were in an over-supply situation, due in part to the production from Chilean brine deposits (Buckley, 1983), and Tanco' s own plans were put into abeyance. The potential alternative market, the direct use of concentrates in the glass and ceramics industry, did not at the time justify the cost of constructing a new plant."

Jan 1, 1986

By Elliott A, Kingsnorth D. J

The development of a large high grade spodumene orebody, in excess of 30M tonnes containing at least 7M tonnes at 4.0% Li20, by Lithium Australia Ltd at Greenbushes, Western Australia is significantly increasing the world consumption of lithium minerals. The availability of two low cost sources of lithium, spodumene concentrates (7.5% Li20) and glass grade spodumene (4.8% Li20) has been welcomed by the ceramic and glass industries as it assists them to lower their raw material costs at a time when they are facing severe competition from alternative materials. While there is no shortage of lithium reserves in the world, there has been a shortage of high quality lithium minerals. The Lithium Australia development has filled this need. The favourable factors of high grade, low impurities, open cut mining and existing infrastructure make this an ideal low cost source for a long term downstream lithium industry. The Lithium Australia mine development has filled the need for a reliable long term supply of lithium minerals. The long term viability of this resource is ensured by the unique combination of the following key attributes of the development : High grade reserves of 7.OM tonnes of 4.0% Li20 within 130 metres of the surface, contained within a total proven reserve of 30M tonnes of 2.8 % Li20. Open pit mining with stripping ratio of less than 2.5:1 waste:ore. Low impurities levels, particularly in those elements, that have a detrimental effect on the colour of glass/ceramics i.e. iron, manganese, titanium and chromium. An existing mine infrastructure that includes an adequate water supply for all foreseeable processing requirements. A sophisticated spodumene concentrator utilizing statistical process control to produce a consistently high grade product with minimal impurities. A technically qualified stable workforce fully acquainted with spodumene processing techniques. Greenbushes high grade concentrates have found ready acceptance in the specialty ceramic and glass industries during the past four years. The consistency and high grade/low impurity level of the product has enabled its use in the production of television tubes, oven to table ware, glass fibres, specialty glasses and ceramic glazes.

Jan 1, 1989

By Emanuele Catelli, Paolo Vicentini, Manuel Petitat, Paolo Lanfranchi

"More than 800 million tons of material will be excavated during large underground projects such as tunnels, undergrounds and power plants by 2030 in Europe only. The raw material excavated is often classified as waste, which involves environmental impact and transport issues: landfill areas, CO2 emissions and noise. But how can such massive amounts of material be transported, processed and deposited? Using the example of the AlpTransit Ceneri Base Tunnel (15.4 km), we show that suitable excavated materials can be used sustainably as a primary resource for tunnel concrete. This requires careful planning of the installations and storage areas by the client, timely building of the processing plants and other handling facilities outside the tunnel and a continuous evaluation of the raw material quality. 1. INTRODUCTION Spoil management is a central element of large construction projects. The systematic reuse of suitable excavated material not only saves natural resources, reduces transport distances and landfill volume, but can also decrease overall construction costs. Ideally, all of the concrete needed for tunnel lining can be produced with this on-site material. Such a natural resource management concept was applied for the construction of the new Gotthard Base Tunnel (L = 57 km). Spoil management concepts are, how-ever, difficult to implement and call for innovative techniques, sophisticated logistics and organization. In the context of large projects, environmentally friendly transport, processing and storage of millions of tons of excavated loose material represent another logistics challenge (Simmen & Lieb, 2010). This paper shows key factors that led to the successful completion of spoil management at the Ceneri Base Tunnel, which constitutes a part of the AlpTransit Gotthard Project (Figure 1)."

Jan 1, 2016