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By Steve Colbum

LTl’s MapStar LPS (laser positioning system) utilize both tripod mounted and hand held reflectorless distance meters. These are eye safe, easy-to-use, and specifically designed to endure the harsh environment characteristic to the mining, quarry and explosives industries. Survey data collected by the systems is digitally stored in a ruggedized data collector and then processed with a specialized, interactive software program, which can be run on any standard PC. Win Prof, the Windows-based analytical software package is used to reduce the data for generating bench face profiles, surfaces, volumes, estimating true burdens and mining ratio calculations. In addition, the software has many other built-in routines to calculate powder factors, toe shear, to map structural contacts and to predict the flyrock potential based on the Burden to Energy ratios. An extensive, built-in library of explosive’s data facilitates these calculations. It will also conform automatically to user-specified minimum and/or maximum burden in relation to the explosive energy, hole diameter and bench geometry - for both vertical and inclined holes. Numerical data can be represented in 2D or 3D to emphasize the hole-burden-face relationships.In this workshop, the MapStar LPS instruments and Win Prof analytical software will be thoroughly demonstrated. Demonstrations include equipment configuration, typical field setups and several effective survey procedures, including processing of some sample data.

Jan 1, 2000

A comparatively new and very promIsmg field for applying cemented tungsten-carbides is in the mining and quarrying industries. The economic advantages of this unique engineering material over the conventional hollow drill steel, or steel detachable bits, have proven so great that the use of "hard metals" promises, in some instances, to revolutionise the drilling of all manner of minerals. Early in the war years the Germans realised the tremendous advantages cemented carbides offered for holing hard rocks, and they proceeded to develop detachable percussion bits to do this work, at the same time evolving fast, comparatively light-hitting driliing machines, especially designed to suit the mechanical properties of the carbide.Here in Australia also, it has appeared that the detachable percussion bit offers the greatest economic benefits to consumers, although the author is well aware that carbide-tipped drill rods have, and may continue to work out satisfactorily in certain mines and quarries.Most drilling equipment at present installed in Australia may be described as being of the heavy hard-hitting variety, so that the designer of an efficient percussion bit has to take special precautions to overcome the problem of fatigue, and to ensure that the inserts are securely mounted in the body with the minimum of internal stress in the carbide.

Jan 1, 1950

By F. A. Rutledge, J. J. Mulligan, W. H. Kems, R. L. Thome

"As a part of the United States Department of the Interior program for the development and use of Alaska raw materials, the Bureau of Mines is conducting an investigation of deposits f nonmetallic minerals accessible to the Alaska Railroad for use in building materials in the Alaska Railroad-belt area. The results of the investigations, to date, indicate that raw materials for the production of brick products are in plentiful supply as clay in the Anchorage area, as fire clay at Sheep Mountain, and as shale in the Healy Creek coal formations near Healy, Alaska.Shale for the production of lightweight aggregate or Haydite occurs near mile 67 on the Glenn Highway, and preliminary tests give excellent results. Physical tests are new in progress on commercial-size concrete building units made with this aggregate. Another shale deposit in the same formation was located at mile 16 on the Matanuska Branch of the Alaska Railroad, and preliminary tests give comparable results.Natural lightweight aggregate in tree form of pumice and pumicite occurs in Katmai National Monument and has been used with excellent results in lightweight-building units in Anchorage and Fairbanks. These deposits will be investigated in more detail by the Bureau of Mines during 1952.One small perlite deposit near Healy, Alaska, showed excellent expanding properties, and the product compares favorably with commercial perlites being used in the States for plaster and concrete aggregates. Additional investigation by the Bureau of Mines to delimit the known occurrence and, if possible, discover others were planned for the 1951 field season.The pumice from Katmai National Monument also was considered for use as a pozzolan in pozzolan-portland concrete. Tests by the Bureau of Reclamation indicate that the pumice sample submitted by the Bureau of Mines would be satisfactory in strength development but is not outstanding. Natural activity is good and is greatly improved by calcination at 1,4000 F. Water requirements and shrinkage also are satisfactory. However, the material is ineffective in reducing expansion owing to alkali-aggregate reaction; and, if reactive aggregate is used to make concrete, it would not insure against excessive expansion. An attempt will, be made during the 1952 field season to delimit pumicite deposits along the Alaska Peninsula more amenable for use in pozzolan-portIand concrete.Because the Railroad belt has such a rigorous climate, insulation for new construction is of prime importance. Luring the Bureau of Mines, investigation of building materials all samples were submitted for chemical analyses as possible sources of raw materials for the production of rock wool, one of the best insulation mediums. Four areas having deposits of the required constitu¬ents were located as follows: Anchorage area, with Potter limestone and argillite; Cantwell-Windy area, with limestone and shale; West Fork of the Chulitna River area, with limestone and agrillite; and Homer-Seldoyla area, with Seldovia limestone and Homer clay. It was planned to take bulk samples of these formations and submit them for testing during the 1951 field season."

Mar 1, 1953

By Michael B. Gilbert

The Woodbury L-73 Tunnel involved the design and construction of a 96-inch tunnel driven through 8,080 lf of very difficult ground conditions. Anticipated ground and groundwater conditions consisted of potentially flowing silty sand with cobbles and boulders, mixed face of sand and sandstone and full face of the St. Peter Sandstone. Actual conditions were similar, although the quantities did change from bid quantities. This paper presents the approach used for development of the GBR regarding risk management. The means of arriving at a fair compensation for variances from the baseline values to address the actual encountered tunneling behavior of the soil, boulder count and its effect on production rates are presented.

Jan 1, 2008

By B. Dubé, R. Friedman, J. Oliver, R. Aubertin, M. Burson, G. Panneton, M. Hamilton, J. Ayer

"The Detour Lake gold deposit is located within the northwestern limit of the Archean Abitibi Subprovince of the Superior Province. Mineralized zones are hosted by a sequence of pillowed and massive flows, hyaloclastite units, and altered ultramafic rocks, and are commonly oriented parallel to a series of high-strain zones that are co-planar to the regional-scale Sunday Lake Deformation Zone. Early in its kinematic history, the Sunday Lake Deformation Zone placed older (2.72 Ga) volcanic rocks of the Detour Lake Formation over younger (2.70 Ga) sedimentary rocks of the Caopatina assemblage. Gold mineralization is also parallel to the position of a laterally persistent siliceous rock unit, the 2.725 Ga ‘Chert Marker Horizon.’ The Chert Marker Horizon coincides with the boundary between the mafic-dominated upper Detour Lake Formation and the ultramafic-dominated lower Detour Lake Formation. Stratigraphic and geochronological data suggest that the Chert Marker Horizon is a deformed felsic volcaniclastic unit. At a cut-off of 0.6 g/t Au, the Detour Lake deposit contains 17.26 million ounces of Au within 445.9 million tonnes of rock grading 1.20 g/t Au. Gold occurs in shear-hosted and extensional vein arrays within rocks of the upper and lower Detour Lake Formation and within the Chert Marker Horizon. The Detour Lake deposit has many of the characteristics of a greenstone-hosted, quartz-carbonate vein deposit; its very large size may be attributed to large-scale rheological controls resulting in the formation of dilatant sites in permissive rock units."

Jan 1, 2012

By K H. Esbensen, K Engström

The conclusion from the debate over the last decade in the mining sector is that, for grade control, reverse circulation (RC) drill sampling gives more reliable results due to less sampling problems than blasthole samples. However, by conducting the latter with well-controlled procedures there still exist fair possibilities to counteract the major blasthole sampling problems and achieve fit-for-purpose representativeness, especially if based on minimal loss of fines. In the present PhD study, extensive replicate experiments and variographic characterisations are conducted to evaluate the performance of manual blasthole (BH) sampling and sectorial segment sampling. The experiments were performed in Luossavaara-Kiirunavaara AB (LKAB)’s Leveäniemi open pit mine in the north of Sweden. The experimental area is an apatite-magnetite iron ore deposit of the Kiruna type, with the demand to exhibit a maximum of local heterogeneity to allow the experiment the largest possible conclusion powers. Gathering and splitting the complete BH drill cutting cones (fines cone, coarse cone) served as an authoritative reference on which to assess the representativity of the two BH sampling methods.Results show that manual BH drill sampling is able to produce samples with an acceptable accuracy and precision if performed properly and with insight. Based on variographic comparison, segment sampling shows similar precision for chemical grades as the manual sampling, while the particle size distributions were more deviating for segment sampling than for manual sampling at the high and low size ranges. Possible reasons for these partly surprising results are discussed.For further investigation of the performance of BH versus RC drill sampling, a second experiment has been planned on a parallel profile. This will result in an unprecedented opportunity for a full variographic comparison between RC and BH sampling, aimed at designing specific, fit-for-purpose sampling procedures as a function of ore quality, cut-off grades and important contaminant levels.CITATION:Engström, K and Esbensen, K H, 2017. Blasthole sampling (replicate and variographic experiments) in LKAB open pit iron ore mines – fit-for-purpose representativity?, Australia, in Proceedings Eighth World Conference on Sampling and Blending , pp 85–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Z. T. Bieniawski, José Miguel Galera, Benjamín Celada

TBM case histories from over 400 tunnel sections are analyzed presenting a comprehensive application of the Rock Mass Excavability (RME) index (Bieniawski et al.2006). The paper introduces two new adjustment factors, called the Factor of Tunnel Length and the Factor of Crew Effectiveness, which were established to represent more realistically the interaction of the rock mass characteristics, the TBM parameters and the performance of the crew operating the machine. A new correlation is provided for predicting the average rate of advance of double-shield TBMs working specifically in the double-shield mode.

Jan 1, 2007

By Urie R. W

Fluidized bed roasting of copper concentrates from Mt. Morgan, Mt. Lyell, Mt. Isa, and Peko was performed in a 3 ft 6 in diameter, slurry fed, pilot plant roaster operated under autogenous conditions to produce calcines with desirable leaching properties. A 12 in. diameter, externally heated roaster, provided with a dry feed system, was also used.An account is given of important factors which influence roaster behaviour and performance, and the effects of operating variables on calcine composition and leaching properties are described. Due to copper ferrite formation, a maximum of approximately 50 per cent of the copper in the calcines may be in the form of CuO before the copper leach efficiency falls significantly below lOO' per cent. Recovery of gold by cyanidation of leach residues was consistently high and independent of roasting conditions.INTRODUCTIONIn traditional practice copper is produced by pyrometallurgical techniques when the ,copper minerals in the ore or concentrate are predominantly sulphides, and by hydrometallurgy when the minerals are oxidized. Copper smelting is most suited to large scale operations, and for many years small to medium size mines with sulphide orebodies have been interested ill; alternative processes.Since hydrometallurgical plants (ie. leaching and electrowinning plants) are essentially unitized, they may be scaled down in output without much loss in efficiency or increase in processing cost, and many proposals have been made for the application of this type of process following roasting of the sulphides to render the copper soluble. However, until the advent of fluidized roasting, it was not possible to control the roasting operations sufficiently precisely to produce calcines consistently of the required leaching characteristics.

Jan 1, 1961

By P. R. Dugan

Sulfur removal from high sulfur coal has several objectives including: a) reduction of the atmospheric load that contributes to the problem of acid precipitation; b) reduction of ash, which contributes to decreased energy transfer in boilers, as well as ash disposal; and c) alleviation of the social and economic dislocations reluted to uneven geographical distribution of sulfur in coal reserves. Cost in relation to the value of refined coal will govern the development of an emerging coal refining industry. Estimation of the premium paid by power companies for coal with a low sulfur content is a good estimate of the value that will be added as the result of refining. Estimates of premiums paid in 1984 are $28.65/t ($26 per st) for reduction of total sulfur from 3’% to 1% S and greater than $28.65/t ($26 per st) for removal below 1% sulfur.

Jan 8, 1987

By Felix E. Mutschler

Alkaline rock-related precious metal deposits include: • orthomagmatic platinum group elements (PGE) ± gold (Au); • porphyry copper-silver-gold (Cu-Ag-Au, ±PGE); • epithermal Au-only, and Au-Ag-base metals; • submarine exhalative Kuroko-, Cyprus-, seamount- and Yellowjacket-type deposits; and • enigmatic deposits akin to Olympic Dam. Coeval epithermal deposits related to porphyry deposits suggest the two types represent separate immiscible fluids evolved in oxidized, CO2-rich alkaline magma chambers. Alkaline rock provinces develop above mantle hot-spots, but crustal structures control the final distribution of magmas and ore fluids. Prospecting guides for alkaline rock-related precious metal deposits include the presence of evolved alkaline rocks, pervasive K-metasomatic, redox and carbonatic alteration and low level Au (±Te, etc.) anomalies. Although alkaline igneous rocks crop out in less than 1 % of the area of the North American Cordillera and craton, alkaline rock-related ore deposits have produced nearly 13% of the total United States and Canadian lode gold production. Large (31-t or 1 million-oz) deposits are common (Fig. 1), and additional deposits and reserves are being discovered. New genetic models are evolving, making alkaline rock-related precious metal prospects attractive exploration targets.

Jan 1, 1991

By F. M. McEvoy, E. J. Steadman, R. Murfin

In England, the provision of aggregate is determined by the historical relationship between construction and aggregate consumption. This approach does not necessarily lead to sustainable decision-making and can be seen as being driven by political expediency, rather than reasonable environmental consideration. The introduction of the statutory requirement for Strategic Environmental Assessment (SEA) in the UK has provided the opportunity to examine this issue on a more rational basis. This paper provides a practical application of a SEA based approach, to the provision of aggregates at a regional level. The process, underpinned by relevant information on resources and environmental assets, suggests that alternative supply scenarios for aggregate provision are tested in a transparent, consistent manner with increased genuine stakeholder consultation. It supports a move away from "predict and provide" approaches to one where aggregates are sourced with the best balance of environmental costs and benefits.

Jan 1, 2005

By G. Sauer

"More Skill is needed to avoid rather than to handle heavy ground loads." This finding, from a tunneling engineer of the nineteenth century, is still relevant today with all advanced sequential excavation and support methods available whether they are applied in the vertical or horizontal direction. Balanced contractual agreements and documents are important since they provide the spirit and climate at the site. This article aims to describe the means and measures for 'hand mined' shaft and tunnel support as they are available today. Some special construction elements and methods with a perspective in recent developments in order to avoid getting stuck in conservatism are presented as well. If we don't allow new methods, means and measures we may end up with the famous quote "Only women who have already proven they are able to give birth to a healthy baby are allowed to become pregnant!"

Jan 1, 2003

By Moskovits E. E

Spodumene was recovered from pegmatite by flotation in laboratory and pilot-plant tests using an anionic collector emulsion. A similar process applied to beryl pegmatite gave encouraging results.INTRODUCTIONOver the past two decades lithium and beryllium have aroused increasing interest in the metallurgical world. Both these light metals have potential uses in nuclear shielding and cooling and in lightweight alloys, and there is a growing demand for lithium chemicals for ceramics, air conditioning and lubricants. The use, technology and history of lithium has been surveyed by Schreck (1961).For many years, the only commercial production of lithium and beryllium was from pegmatite deposits amenable to hand cobbing. The most important minerals of these ores are spodumene and beryl, which are respectively lithium aluminium silicate and beryllium aluminium silicate. Norman and Gieseke (1940) investigated the treatment of lithium ores by froth flotation. The process of flotation of the pegmatite constituents away from the spodumene was applied commercially in 1951, and the operation has been described by Goter, Rainey and Hudspeth (1953). Subsequently, the flotation of the spodumene from the pegmatite was studied by Munson and Clark (1955) and Browning and McVay (1961), and this method has superceded the reverse flotation process commercially. Muskett, Tasker and Hobson (1962), in applying the method of Browning and McVay in pilot-scale tests, reported difficulty because of activation of quartz and felspar by iron salts introduced during milling of the ore.The flotation of beryl, reported by Ashton and Weir...

Jan 1, 1963

By A. Drouin, D. Lemieux, C. Chouinard

"A gold bearing pyrite concentrate was treated at the demonstration scale (15 t/d) for the extraction of gold using a cyanide-free process. The pyrite was depressed in the flotation circuit in order to promote the flotation of copper and to achieve a sufficient copper grade to meet the copper smelter criteria. However, the recoveries of copper were 80% and only about 50% for the gold was found in the copper concentrate. The balance of the gold (50%) and copper (20%) contained in the pyrite concentrate as a reject from an overall flotation circuit. The gold grade in the pyrite concentrate is 5.40 g Au/t and copper about 0.77%. About 170 tons of pyrite concentrate were processed in the DST demonstration plant. The concentrate was first oxidized using a fluid bed to produce a calcine. Copper was then extracted as copper sulphate using diluted sulphuric acid. The residual solid was submitted to the DST chlorination process for gold extraction. Thereafter, the gold was recovered from the pregnant brine by precipitation over silica using DST proprietary process. The maximum gold recovery by chlorination was 90%. The average gold recovery by cyanidation of these calcines was 71%.IntroductionDundee Sustainable Technologies (“DST”) has developed a chlorination process as an alternative to the conventional cyanidation process for the extraction of precious metals from ores or concentrates. The technology offers viable and efficient gold recoveries and the ability to handle refractory ores and contaminated material (As, Hg, etc..). The process was successfully demonstrated on hundreds of samples provided by various mines, exploration and development projects and has evolved from laboratory experiment to demonstration at an industrial scale.DST’s chlorination process operates in a closed loop circuit, which implies that no liquid effluents are generated. The chemistry and process design allows precious metal deposits containing base metals to be treated viably. The tailings from the process are inert and non-toxic, sulphide depleted and thus non-acid generating. The efficiency of the process has demonstrated excellent gold recoveries within a fraction of the time needed for cyanidation to obtain similar results. The company completed in 2015 the construction of the first industrial demonstration plant operating with the DST technology. The plant has a capacity of 15 tons per day of mineral concentrate, and the ability to extract gold and silver utilizing DST chlorination technology.DST has tested its chlorination technology at demonstration scale on the refractory pyrite concentrate containing 5.40 g Au/t and 0.8 %copper. This auriferous pyrite concentrate, was by-product of copper concentrate respecting the copper smelter norms, is produced in a country where cyanide is prohibited and refractory to cyanidation. The pyrite concentrate was initially processed successfully (gold recoveries: > 90%) by the DST technology at laboratory (2011: 20 kg) and pilot (2014: 5 tons) scales to extract gold. About 170 tons of this pyrite concentrate were processed in the DST demonstration plant located in Thetford Mines."

Jan 1, 2017

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

By Hargraves A. J

The paper outlines events at the Collinsville State Coal Mine, Queensland, leading to the practice of full face multiple shotfiring in bord and pillar development places. The 1954 disaster is referred to, and factors involved in simultaneous shotfiring in coal are discussed. Promising preliminary multiple shotfiring tests at the Colliery are described, as well as the resulting routine measures adopted, and the changes involved. The subsequent inducing of two outbursts under safe conditions by remote multiple shotfiring is given as justification for the changes made.INTRODUCTIONFollowing a disastrous instantaneous outburst (1.0.) of coal and gas at the Collinsville State Coal Mine in 1954, the necessity for inducer shotfiring for the control of possible further outbursts was established. However this mine, immediately classified as gassy after the 1954 outburst, is subject to the general restrictions pertaining to gassy mines which at present preclude the use of inducer shotfiring due particularly to the non-existence of a permitted exploder for more than six shots, and further, because permitted multipleexploders are not designed for remote firing through long lengths of cable. This situation was met by arresting or reducing progress in the production places, thereby reducing the danger of outbursts while means were being considered to achieve overall maximum safety.In August 1957 two full faces were successfully blasted in experimental simultaneous rounds. In June 1958 four full faces were blasted, and in October 1958 full face grunching without prior cutting, Le. inducer shotfiring, was introduced in No. 1 Tunnel as a production feature. In March 1960 it...

Jan 1, 1960

By X. Yuan

"The processing behaviours of ores such as their liberation characteristics in comminution and their response in separation processes are affected by their mineralogical characteristics. Key ore characteristics which are relevant to processing, such as mineral proportions, mineral grain size, grain shape and mineral associations are routinely measured at the micro-scale in polished section using optical microscopes and SEM-based automated mineralogy systems. The application of X-ray micro-tomography to mineral processing provides the means to quantify these important micro-textural characteristics in three dimensions, removing the stereological issues encountered when measuring volumetric information in two-dimensional polished sections. In this paper we present several examples of ore textures to illustrate where X-ray micro-tomography can be applied successfully to obtain quantitative measures of ore characteristics which are useful in a variety of process modelling applications.INTRODUCTION X-ray tomography has been used as a tool in medicine for some years and is being applied in a wider range of fields including geology, palaeontology and mineralogy. In this paper we present some applications of X-ray tomography in mineral processing applications being developed at JKMRC. The availability of SEM-based automated mineralogy systems such as MLA and QEMSCAN has seen the increased use of quantitative mineralogical data measured in two dimensions in the design, operation and simulation of mineral processing plants. When the ore is amenable to measurement by X-ray tomography this technique can provide quantitative data for characteristics such as mineral grain size, shape, mineral associations and liberation in three-dimensions. The advantage of measuring these characteristics in three-dimensions is that the stereological issues which bias measurements made on polished sections are removed. X-ray tomography also quantifies the location of mineral grains relative to one another in space - a useful descriptor of ore texture. Like many measurement techniques X-ray tomography has advantages and disadvantages when compared to other techniques. One limitation is that the ability of the X-ray tomography system to discriminate between minerals is a function of the X-ray attenuation of those minerals. While the X-ray attenuation of many common minerals is sufficiently different for X-ray tomography to distinguish between them, there are some where the overlap in X-ray attenuation makes discrimination on the basis of this characteristic alone impossible. An example of this would be chalcopyrite and magnetite. However where the ore mineralogy is suitable to apply X-ray tomography, the technique provides some exciting opportunities to explore the relationship between texture and ore processability."

Jan 1, 2012

Atlas Copco Wagner launched its ST1010 Scooptram load haul dumper. The ST1010 replaces the company’s Wagner ST-1000 Scooptram. The improvements to the Wagner ST1010 include increased reliability, ease of maintenance and driver comfort or ergonomics. The ST1010 has been redesigned and has added several new features and options not offered in the earlier model. These include anew boom design with side stops. Heavy reinforcements to the bogie offer better protection against the harsh working conditions in underground mining and tunneling. An auto lube system has also been added as has paint-on grip tread to reduce slips and falls during maintenance checks or repair work. Other features include a heavy-duty, auxiliary-fan motor, an isolated transverter, remote diagnostic pressure taps, a bolt-on battery box, raised air-intake, improved fuel-filter access for easier maintenance, larger wear-bars around the engine tub, and smaller, higher output batteries

Jan 1, 2000

By O Haavisto, N Khajehzadeh, L Koresaar

Online analysis of metal content can be used to optimise the grade and recovery of a flotation circuit. Compared to conventional laboratory analyses, the benefit of an online analyser is the speed of the measurement, therefore disturbances (eg changes in feed grade and decrease in recovery) can be reacted to in real time by an operator or automatic process control system. In some cases traditional X-ray fluorescence analysers can be applied to silica analysis in iron ore when the SiO2 grades are high enough and have a negative correlation with iron; however, generally a laser-induced breakdown spectroscopy (LIBS) analyser is more suitable for low Z elements.The Outotec Courier 8® analyser is a LIBS based analyser able to measure elements starting from lithium (Z = 3), thus being able to measure impurities; eg silica and aluminium directly in iron ore slurries. Besides online elemental analysis, the analyser can be combined with optical measurements for rapid continuous measurement of each sample line. Laboratory testing has also shown potential for mineralogical analysis using the combination of LIBS and reflectance spectroscopy.CITATION:Koresaar, L, Khajehzadeh, N, Haavisto, O and Timperi, J, 2017. Online elemental and mineral measurement of slurries in iron ore beneficiation, in Proceedings Iron Ore 2017, pp 561–566 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By H. E. Criner, M. G. Driessen

THE cyclone thickener has two important applications in wet washing plants: (1) water clarification, and (2) fine coal recovery. The thickener consists of a conical chamber into which the fluid is injected through a tangential nozzle at the periphery of the large end. The solids of the slurry are concentrated and removed from the apex of the cone while the "thinner" portion is discharged from a central tube in a flat head at the large end, fig. 1. The advantages of the cyclone thickener are that large volumes of slurry may be treated with small space requirements and that the underflow concentration may be controlled easily and readily to meet varying feed conditions. Control of Washery Water Solids Concentration: The first requirement, in the process of controlling solids concentration, is that the solids be removed from the body of circulating water at the rate at which they are introduced. If this condition is satisfied the concentration will remain at a fixed value and will not increase to uncontrollable levels. The second requirement is that the solids concentration

Jan 1, 1951