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By Soumitry J. Ray

Poor visibility of powered industrial vehicles, such as forklifts, used in industry is often the cause of accidents that include pedestrians. Current standards allow up to 20 % non-visible regions for forklifts where measurement of these regions is performed by using lamps. A collaboration of research organizations, including National Institute of Standards and Technology, Georgia Institute of Technology (NIST), and Direct Dimensions, has been evaluating advanced methods for measuring a forklift operator?s visibility. These methods can potentially improve visibility standards. They can also help forklift and sensor manufacturers to determine (1) how visibility-assist sensors and algorithms can be designed and (2) where sensors can be mounted on forklifts. This paper includes explanation of visibility measurement experiments performed and results, associated language suggested to standards organizations, and a prototype design for measuring the visibility of forklifts automatically.

Aug 1, 2013

By Z. Jun, L. Kerning

Jinlong copper smelter and refinery, originally designed for 100,000tpa primary copper and started up in 1997, has been expanding its capacity on the basis of operational optimization and by modifying its facilities. Currently it is producing 210,000tpa primary copper, and the new phase of expansion project with a target capacity of 350,000tpa primary copper is ongoing. This paper reviews problems and improvements made with operation and equipment in the past years. Recent plant operation is briefly described. The expansion projects completed are summarized and the ongoing expansion project is present.

Jan 1, 2007

By M. Noaparast, N. Nickoletopoulos, André R. Laplante

"This paper presents an application of the use of synthetic ores to study gold recovery by gravity. Three case studies are presented: the first focuses on the use of tungsten to study applications of Knelson Concentrators for upgrading gravity concentrates; the second on tungsten again, in this case to study the performance of a 86 Falcon Concentrator; and the third on lead to mimic gold's grinding behaviour.It is shown that the use of synthetic ores with metallic substitute for gold is not only expedient, but it can also lead to an increased understanding of separation and grinding mechanisms, because of the more accurate results and controlled particle shapes. The case studies highlight the problems associated with gold particle flakiness and gangue density. The grinding behaviour of malleable materials is shown to be complex, as particles can migrate to coarser size classes by flattening and cold welding, and to finer size classes by folding and actual breakage.IntroductionThe title of this contribution is not entirely misleading. Mineral processing has much to do with philosophy, rather Philosophy, as described by Georgius Agricola:""Furthermore, there are many arts and sciences of which the miner should not be ignorant. First there is Philosophy, that he may discern the origin, cause, and nature of subterranean things; for then he will be able to dig out the veins easily and advantageously, and to obtain more abundant results from his mining. ""1"

Jan 1, 1995

By Derrin A. Auerswald, Jacolien P. Wyethe, Nanne M. \/egter

Base and precious metal refineries often produce effluent solution and slurry streams containing between 50 mg/L and several grams per liter of base metals. Metals have historically been precipitated from these streams with lime to produce effluent streams at pH values between 8 and 9. This effluent treatment process generally does not remove alkali and alkali-earth metals or halides efficiently and with more stringent environmental legislation, more sophisticated effluent treatment plants must be considered which could for example incorporate sulphate removal with ultra-filtration, or the SavminTM process, followed by reverse osmosis for the removal of halides. The flowrates of effluents are often high and if base metals can be recovered before neutralization, the revenue generated from this stream can reduce the cost to produce clean water significantly, and in the case where high concentrations are disposed of, result in a profitable operation. As an add-on to an existing the plant the recovered metal is upgraded and recycled to the plant, but the production of a saleable metal can also be considered. Technology selection for metal recovery depends on the composition and flowrate of the effluent, but could incorporate resin-in¬pulp or other ion-exchange technology; precipitation as sulphides, hydroxides or carbonates; or solvent extraction. This paper describes, as a case study, the technology selection process and uses data from Zincor. Zincor is a division of Exxaro Base Metals (Pty) Limited, a subsidiary of Exxaro Resources Limited.

Jan 1, 2011

By R. Burns, A. I. A. Salama, M. W. Mikhail

"Large amounts of oil sand tailings are produced in the Fort McMurray area, including sand, clays, and misplaced bitumen. The objective of the present study (as part of the overall engineered tailings program) is to select and evaluate the role of hydrocyclones in removing most of the solids from the tailings slurry and producing an underflow product containing about 75% solids.Multistage cyclones were evaluated in pilot plant tests. Slurry feeds with different percents solids and increasing ratios of superfines (–44 µm) were used in testing multistage cyclone circuits. A two-stage Linatex separator circuit gave high recovery to the underflow of 98.8% to 99.6% by mass with the desired high solids content in the underflow of 73% to 75% by mass. Changes in feed solids content (20% to 50%) had little or no influence on cyclone underflow recovery and solids content. The keys to achieving such results were the apex control mechanism and operation at relatively low feed pressure (<60 kPa for 23 cm F cyclone) when the feed solids content was high. Increasing superfines above 7% by mass in the feed resulted in a significant reduction in the recovery to the underflow, probably due to the heavy medium generated by excessive amounts of clays in the cyclone. Pilot plant results were better than those predicted by available cyclone simulation models in terms of recovery and solids concentration in the underflow.Increasing cyclone diameter from 23 cm for the Linatex separator to 51 cm for the Krebs cyclone appears to have little or no effect on size cutpoint."

Jan 1, 1997

By Jamie N. Burdeski, Susan E. Hartfield-Wünsch

Aluminum sheet use has been steadily increasing in the automotive industry to achieve mass reduction and improve fuel economy. One significant manufacturing challenge for aluminum sheet implementation is the reduced formability compared to the steel alloys it replaces. This paper includes friction results from the draw bead simulator (DBS), twist compression (TCT) and strip draw (SDT) tests, for two oil based lubricants and four hot melt lubricants. Formability testing was done with the same lubricants and materials, testing in pure stretch with a hemispherical punch, and in draw with a breadpan shaped die.

Jan 1, 2015

By N. T. Avard

THE Joggins coal field, Cumberland county, Nova Scotia, is on the easterly side of Chignecto bay, at the head of the bay of Fundy. In area, so far as proven, the field extends easterly from the town of Joggins about fifteen miles to Chignecto. The distance across the outcrops of the several seams exposed is approximately one mile. HISTORY Early records of coal mining in this locality are somewhat obscure, but it is known that prior to 1750 the French settlers were mining coal for their own use from the seams which outcrop in the floor of the bay adjacent to the shore, where, at low tide, the reefs are bared for a mile or more. Coal was also mined from the seams outcropping in the cliffs. It is known, too, that at Joggins coal has been mined commercially for over one hundred years. At first, all shipments were made by water, but in 1882 a railway connecting with the Intercolonial railway at Maccan was built to serve this field. GEOLOGY Due to the abundance of fossils in the strata forming the Joggins cliffs, this area was for many years a mecca for geological students from all over this continent. A &apos;sunken fcrest&apos; in the shoreline was of particular interest but, due to constant erosion by the sea, this has apparently been all washed away. On the Joggins shore, the cliffs stand sixty to one hundred feet high, and six workable coal seams, with numerous smaller ones, are there exposed. Others outcrop in the reefs extending from the shore toward the bed of the bay. In working underground, fossilized trees are often found immediately overlying a coal seam, and standing at right angles to the pitch of the seam. This is said to be an unusual condition. In most cases, the bark of the tree is a fine-quality coal, with high carbon content, whereas the pulp has turned to &apos;stone&apos;. There is a definite tendency for the coal to run out, or turn to shale. One seam, workable two miles from the shore, has almost completely disappeared in the outcrop at the shoreline. ? It was thought that a large area could be mined under the bay from an opening near the shore, but the first submarine level had to be abandoned at a distance of 4,000 feet, where the coal became very dirty and shaly, and the mine able area to the westward became more restricted as the mine was developed to the deep. This tendency is common to all seams.

Jan 1, 1944

Several inorganic reagents and organic polymers were tested as depressants in the single mineral flotation of ultrafine iron oxide and hydroxylapatite with Dowfroth 250 as a frother. It was observed that the inorganic reagents and the low molecular weight polymers generally caused dispersion of the ultrafine particles, and consequently their recovery into froth products more or less equaled the recovery of water. On the other hand, the high molecular weight polymers caused different degrees of flocculation of the ultrafine particles, and their recoveries were much lower than the recovery of water. These observations pointed to a need to re-define flotation depressants in fine particle flotation. The traditional definition of a flotation depressant, i.e., to make particle surfaces hydrophilic by forming a hydrophilic film and/or by removing collector and activator coatings, is sufficient for relatively coarse particles. However, to prevent fine and ultrafine particles from floating, a successful depressant should not only make the particles hydrophilic, but also enlarge the particle sizes so that they do not enter the froth product by mechanical entrainment. Polymeric depressants are ideal for these purposes. The different schemes to use polymeric depressants in the selective flotation of fine and ultrafine particles were discussed These schemes involve the integration of the polymeric depressants into other size enlargement processes such as shear flocculation, oil agglomeration, etc., for hydrophobic particles.

Jan 1, 2004

By J. E. Shigley

The gemological properties that allow natural emeralds and blue sapphires to be distinguished from other gemstones are summarized in this paper. A variety of synthetic and laboratory-treated emeralds and blue sapphires are also encountered in the jewelry industry today. Gemologists distinguish these latter materials from their natural counterparts based primarily upon features seen with magnification, such as inclusions and/or growth zoning. In some cases, however, these observations and standard gem-testing methods are insufficient, and the use of non-destructive analytical methods, such as optical spectroscopy and chemical analysis, are required for positive identification. The commercial value of synthetic and treated gems are much less, and can be insignificant in comparison to that of an important untreated natural gemstone. Identification of synthetic and treated gem material is essential to maintaining integrity in the jewelry industry. Loss of consumer confidence in the gemstones sold at the jewelry counter could have a negative impact on the exploration and mining of natural emerald and blue sapphire.

Jan 1, 1998

By A. Desbiens, R. del Villar

"This two-part paper summarizes the design and implementation of a distributed PIbased control strategy installed at the B grinding circuit, at the Kidd Creek Division of Falconbridge Ltd. Part I details the design of the control strategy using a grinding circuit dynamic simulator (DYNAFRAG). The first step consisted of sampling campaigns and data processing to calibrate DYNAFRAG. Then, several control alternatives were designed and tested with the simulator. The main feature of these strategies is their ability to regulate or keep within an upper and lower limit five output variables (circulating load, rod mill density, cyclone feed and overflow densities and pump box level) with only three manipulated variables (rod mill water, pump box water and rod mill tonnage). By simulation on DYNAFRAG, it was possible to discriminate among several control structures. The preferred control strategy uses a saturation algorithm, which allows the adequate regulation of two measured variables with only one actuator. Controllers located in interacting loops are appropriately tuned, taking into account the existing process coupling. Part II will present the implementation of the selected control strategy.IntroductionSteady state simulators are used to predict the stationary state of a given process under specific operating conditions. Tradi - tionally, steady state simulation has been applied for process flowsheet design, for evaluating process modification benefits or for determining key operating parameters in process operation optimization. Dynamic simulators add a new dimension to process simulation since they allow the prediction of the process transient behaviour, resulting from the application of a different set of operating conditions and/or from natural disturbances or equipment failure. Dynamic simulators can also be used for the training of new operators or for the design of control strategies."

Jan 1, 1997

By C. McLachlan, J. R. Donald

"Positioned at the forefront of the seafloor minerals industry, DeepGreen Resources is on track to becoming a leading producer of base and strategic metals obtained from vast high-grade seafloor polymetallic nodule deposits. DeepGreen believes the seafloor minerals industry is an opportunity for developing a more environmentally and societally attractive way to produce cleaner base and strategic metals. Polymetallic nodules contain nickel, manganese, copper, cobalt and other base and strategic metals. Polymetallic nodules represent an exceptional multi-metal-bearing resource, and no current metallurgical operation or flowsheet exists that can recover the primary metallic values while managing the distinct mineralogy. DeepGreen Resources is developing a new process to maximize the business outcomes consistent with the highest environmental standards, including targeting a near zero waste facility. The present paper discusses the history, context and driving forces of polymetallic nodule project development. An overview of DeepGreen?s Nauru Ocean Resources Inc. (NORI) project is presented along with a literature review of polymetallic nodule processing and the on-shore project development scope and plan at DeepGreen Resources is outlined.INTRODUCTION AND CONTEXT Polymetallic Nodules in the Clarion-Clipperton Zone Containing nickel, cobalt, copper and manganese, polymetallic nodules occur in most oceans of the world. The nodules lie on the seafloor sediment. The largest deposit in terms of nodule abundance and metal concentration occurs in the Clarion-Clipperton Zone (CCZ) on vast abyssal plains at a depth of 4,000 to 6,000 metres. The CCZ is located almost entirely in international waters as presented in Figure 1. It has been estimated that the CCZ contains (International Seabed Authority, 2010): •,>21 billion tonnes of nodules; •,>270 million tonnes of nickel; •,>6 billion tonnes of manganese; •,>234 million tonnes of copper; •,>46 million tonnes of cobalt. There are several active hypotheses for the mechanism of formation of the nodules including precipitation, hydrothermal decomposition of basaltic debris, and involvement of microorganisms. Nodules require a nucleus to start forming, which could be a piece of pumice, a shark tooth, old nodule piece, basalt debris or even microfossils like radiolaria and foraminifera. Nodules form concentrically with layers of iron and manganese hydroxides around a core. Although composed mainly of Mn, Fe, silicates and hydroxides, it is the significant content of Ni, Cu, Co, Zn and Rare Earth Elements (REE) that is generating the economic interest in harvesting these deposits. Nodules vary in size from micro-nodules to about 20 cm, the common size being two to eight centimeters. A typical polymetallic nodule and polished cross-section is presented in Figure 2."

Jan 1, 2017

By R. A. Hemstock

"Simple classification systems are now being used which will describe adequately the surface vegetation, the topography and the peat for any muskeg condition. Good progress is being made in determining some of the mechanical properties of muskeg and it is apparent that the science of soil mechanics will apply largely to these studies. Correlation is also indicated between shear strength as determined by the shear vane tester and vehicle performance. Several tracked vehicles are now available which perform well in muskeg and advances in this field have come rapidly in the past few years. Testing is under way on the largest of all muskeg vehicles -the thirty-five ton Musk Ox. This vehicle will fill the last gap for the oil industry and will make possible the movement of large drilling rigs at any season of the year."

Jan 1, 1960

By R. D. Lawrence

"Suggestions have been made that the appraisal of mining assets using discounted cash flow techniques should be based solely on proven and probable reserves in reliance upon the widespread international recognition of uniform resource definitions. Following a review of general accepted valuation principles, a survey of the literature and, most importantly, a review of real transactions in the open market, it is clear that valuators should not be constrained by the growing acceptance of modern mineral resource codes. On the contrary, valuation practitioners should be encouraged to examine all classes of mineralization and, after making due allowance for risk, to utilize all mineral resources as a basis for determining fair market value.INTRODUCTIONGreat strides have been made recently in achieving an international consensus on mineral reserve and resource definitions and classifications. The Australasian JORC code, the CIM code in Canada, the SME proposal in the United States and even a proposed code from the United Nations have all brought the objective within reach.Unfortunately, this success has led to another problem for mineral valuators. Certain securities regulators, tax collectors and their ilk have begun to expound on the opinion that discounted cash flow projections carried out to calculate net present values that would form the basis for a valuation determination should be based solely on proven and probable reserves. The author disagrees with this position. This paper examines the subject from four points of view:"

Jan 1, 2003

By Harry V. Warren

THE Dolly Varden Mine is situated in the Kitsault River valley, eighteen miles from the head of Alice arm, in the Nass River mining division of British Columbia. During the years 1919-21 it was operated by the Taylor Engineering Company, Limited, and produced 1,300,000 oz. silver from about 36,000 tons of ore. The ore was transported by narrow-gauge railway to Alice arm, and shipped to the smelter at Anyox for treatment. During recent years, a small quantity of high-grade ore has been extracted by leasers and shipped to the smelter at Tacoma, Wash. Unfortunately, the bonanza ores which occurred near the surface did nor persist to depth, and two hundred feet below the exposures only rare and unimportant patches of ridi ore have been found. Two opinions exist as to the origin of this rich silver ore. One, advanced by V. Delmage (1, 2), is that the ores are hypogene, and the other, by G. Hanson(3, 4, S), is that the ores are the result of supergene enrichment. It is true that Dolmage first advanced his view that the ores are primary because they appeared to be analagous to Premier ore, which he had studied in detail and which he considered to be primary. The present authors have had access to excellent suites of material from both mines and consider the comparison well taken, the only essential mineralogical difference being the presence at the Premier mine, in addition to the silver minerals, of gold and electrum. Although the arguments put forward by Delmage have, in the opinion of the authors, never been refuted, nevertheless R. P. D. Graham(6), in a reference to the mine published in 1924, describes the ore as of supergene origin, and since then nobody appears to have challenged this statement. Indeed, in 1935, Hanson re-affirmed his earlier conclusion(5).

Jan 1, 1942

By R. O. Suzuki, S. Natsui, R. Nashimoto, T. Kumagai, T. Kikuchi, H. Takai

A newly developed computational fluid dynamics model based on a multi-phase particle simulation is presented for predicting the entrainment behavior of liquid metal into slag due to rising single bubble. By comparing results calculated using this model against experimental data, it was found that the transient behavior of bubbles and the two immiscible liquids can be accurately estimated by this method. The rupturing of the thin water film surrounding the bubble was less reliably predicted, but this 3-dimensional unsteady numerical model still nevertheless provides valuable new information for directly predicting the change in the liquid-liquid interface over time. This model predicted the Young-Laplace pressure, and the interface shape was simulated with volume conservation using this model as opposed to the conventional particle method. This simulation model can calculate both of dispersed phase and continuous phase seamlessly.

Jan 1, 2015

By Washington Luiz Mafra

Every year the conventional direct reduction processes ? Midrex and HYL III ? increased their market share in the world steel production, even though they are only economically feasible in countries where natural gas is available at competitive prices. In this context, the new Midrex projects are based on large reactors (Megamod - 1.5 to 1.8 Mt/y of DRI), reduction temperatures of the metallic burden up to 850oC, with bustle gas temperatures between 960oC e 1050oC. Thus, the requirements of metallic burden performance, as well as the evaluating methods, usually based on ISO standards, need to be reviewed. It is well known that the standards usually applied to quality evaluation do not reflect the performance of metallic burden inside the reactors. This paper describes the different methods of evaluating the disintegration under reduction of DR pellets based on ISO 11257 standard. This is the most important method used by pellet producers and customers for evaluating DR feedstocks. The different methodologies tested to evaluate the disintegration under reduction had varying results, evidencing the relevance of the method and the quality of the pellet. Nevertheless, validating the method in an industrial reactor is still fundamental.

May 1, 2007

By W. Lodge, G. Rasmussen

"The carbon-in-pulp (CIP) process has been the dominant gold recovery technology since the 1980s. During all this time carbon measurement, and control of the carbon transfer pumps has been largely manual in nature. Such manual operation inevitably limits process efficiency, potentially resulting in higher gold solution losses, and higher cost of circuit operation. Based on the authors’ experience, average plant solution loss is in the range of 0.02-0.03 ppm Au, as opposed to the general industry target of 0.01 ppm Au or less. Gekko Systems, in conjunction with Curtin University’s Gold Technology Group, has developed a carbon concentration meter, the ‘Carbon Scout’ meter. The meter automatically measures carbon concentration in all tanks, providing more frequent and more precise data. Combined with SIMCIL, a CIP circuit process model which is used to determine the optimum set points for the circuit, the meter should ensure lower gold solution losses, and more efficient operation of the carbon circuit. This paper will review they critical factors for good carbon management, the development of the meter and results from the first plant installation. Additional benefits of the Carbon Scout, including improved health and safety and the opportunity to measure other key variables in the leach/adsorption circuit from one central location will also be described.INTRODUCTION The carbon-in-pulp (CIP) process was first introduced to the gold industry in the early 1950s at the Carlton Mill in the USA (Fast, 1988), with the modern version of CIP becoming fully developed with large scale installations in South Africa in the late 1970s (Laxen, 1982). CIP quickly became the technology of choice for new operations, and for the retrofitting or upgrading of existing operations. In the 1980s the carbon-in-leach (CIL) circuit configuration became the process design of choice due mainly to its lower capital costs. With 40 years of operational experience, CIP/CIL for gold recovery is now mature a technology, whose operations and limitations are well understood. To extract further efficiencies from such technologies, by improving recoveries and/or reducing operating costs, is challenging and may require new approaches to circuit management. Gekko Systems, in association with the Gold Technology Group at Curtin University, has developed the Carbon Scout, an automated carbon measurement device. This device replaces manual measurement of carbon concentration in carbon adsorption tanks, providing more frequent and more accurate data for control of the CIP process. Data from the Carbon Scout can be used to automatically control the carbon forwarding pumps."

Jan 1, 2018

By A. McLean, X. Men

"With high quality sulphide ores diminishing, nickel production from low-grade oxide ores becomes increasingly important and a major concern is the high sulphur level in the resultant ferro-alloy. So, desulphurization of the ferronickel becomes an important consideration. Red mud is a waste product of alumina industry and causes adverse effects on environment. In the present study, experiments were conducted to determine feasibility of using red mud as a major ingredient of refining fluxes for ferronickel desulphurization. In view of their influence on slag-metal separation, contact angle measurements between ferronickel alloy and molten slag made from red mud were also determined. INTRODUCTIONNickel is a very important metal that finds a variety of applications including consumer products, building, automotive and electronics. There are two kinds of ores containing nickel, namely oxide and sulphide ores. Anthony and Flett [1] reported that about 55% of the world’s nickel production originates from sulphide ores while the balance of new nickel is derived from oxide ores. However, oxide ores count for about 70% of the worldwide reserves. Apparently, oxide ores will play a significant role in the production of nickel in the future. Most of nickel produced using oxide ores is from pyrometallurgical processes namely ferronickel smelting or matte smelting. So, we can draw such a conclusion that using nickel oxide ores to produce ferronickel will become more and more important .Before used to make stainless steel or other materials, the ferronickel need pretreatment to remove impurities especially sulphur and phosphorus that will cause negative influence on the properties of steel product. Red mud is a by-product during alumina production. Usually, about 1 to 1.5 tons of red mud will be produced when we get 1 ton of alumina. About 90 million tones of red mud are produced every year in the world [2].Red mud is deemed as a toxic industrial waste which needs treatment before discharge because of alkalinity and chemical and mineralogical properties. Until now, the main means to deal with red mud are to store it in impoundments or dump it in the sea depending on local environment. Nowadays, how to recycle red mud has become a pretty hot topic around the world. The last 40 years have witnessed a lot of patent applications concerning the ways of red mud utilization. However, a little amount of red mud is consumed until now due to the limitations of recycling red mud."

Jan 1, 2012

Keeping the sediment on the mine site and out of the water course is essential from the regulatory, environmental and sustainability perspectives. Regulation of this aspect of mining is embedded in environmental legislation and government receiving water quality standards, and government control has apparently been considered to be the most appropriate method to define mine site discharge standards and the environmental implications of sediment in downstream watercourses. A literature search for guidelines for the site specific design and operation of sediment ponds treating mine site runoff to remove total suspended solids, turbidity and flocculant-induced toxicity, revealed little information on the mining industry?s and government?s roles in defining the ?how to achieve? related to sediment pond design. Is there a need or reason for an industry-driven leadership to clearly define the ?how to? keep the sediment on the mine site and out of the water course? Currently, this issue is addressed in Canada by a federal mining regulation for metal mines which specifies discharge quality for sediment. This paper focuses on the method used in British Columbia, Canada, to regulate and provide a scientific methodology to control the discharge of sediment from mine sites. Management plans relative to this topic are discussed and are considered to have value from the exploration, construction, operation and the onset of closure phases. In addition, the balance and linkage between the erosion control management plan and the sediment pond management plan are discussed in terms of how they may be designed to complement each other to lower the risk of exceeding discharge and receiving water quality standards. If there were an industry-driven standard, or guidance document relative to addressing sediment release, it would benefit mining companies by eliminating the repetitive analysis of this topic for each new mine, mine expansion, and mine modification; also, government may often replace certain aspects of permitting with a regulation, if there is a government/industry established standard defining Best Achievable Technology (e.g. the Canadian Metal Mining Effluent Regulations).

Aug 1, 2013

By A. Boehm

"For recycling LD slag into the steel making process, the phosphorous containing calcium silcate phases have to be removed from iron oxide phases. One possible technical solution could be magnetic separation in a wide range of susceptibilities from ferromagnetic to paramagnetic. To check the feasibility of magnetic separation the distribution of the magnetic susceptibility in size classes as well as the liberation of the phosphorous containing phase were evaluated by a new method combining two dimensional physical property analysis with QEMSCAN analysis. The particle size classes of energy controlled comminution products were subdivided into fractions of defined magnetic susceptibility using a hand magnet of well known field properties (pick up method). On the one hand the susceptibility classes were wet assayed on the other hand analyzed by QEMSCAN followed by data evaluation using iDiscover 5.3.1(FEI), which was adapted to the data structure of two physical properties (size and magnetic mass susceptibility). The results allow the comparison of mass based (3D) cumulative distribution of grades from the wet assays with the area based (2D) distribution from QEMSCAN analysis, in order to control a systematic (size dependent) stereological error for this special type of material. As the physical separation property forms a crucial parameter the results from the liberation analysis by QEMSCAN can be interpreted more profound with respect to an expectable separation result. Once the various mineral compositions of the particles are assigned to the physical properties the Henry Reinhardt chart serves to predict the best possible separation result and thus the feasibility of a separation technique.INTRODUCTIONThe two Austrian steel plants operated by voestalpine AG produce about 650,000 t (voestalpine 2014) of LD slag in the course of steel production from pig iron according to the basic oxygen process blowing oxygen in the converter by an oxygen lance. The process is also known as the Linz Donawitz (LD) steelmaking process. By the addition of lime (CaO), carbon, phosphorus, silica, manganese and sulfur, which are present in the molten pig iron, shall be oxidized and bound in the slag either as oxide or silicate phases, or leave the slag in the gaseous phase (CO). The average chemical composition of the investigated LD slag is given in table 1."

Jan 1, 2016