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By J. E. Dickinson, J. L. Sutherland, J. Zhou, M. J. Cole, K. P. Galvin

Interest in early gangue rejection has grown substantially in the minerals industry to reduce energy and water consumption arising from excessive comminution. Recent developments in coarse-particle flotation have proven successful by promoting a quiescent hydrodynamic environment to limit particlebubble detachment and by helping to convey more buoyant particles to the overflow. Current approaches also benefit from upstream classification to remove the finer particles ahead of the coarse-particle flotation. In this study, coarse-particle flotation was investigated experimentally using a novel hybrid gravity-flotation system called CoarseAIR™ that exploits the hydrodynamic advantages of the Reflux® Classifier. The system consists of a lower fluidised bed housing, with a system of inclined channels above. The inclined channels enhance the segregation and hence rejection of intermediate through to relatively coarse particles containing little or no surface liberation. This approach overcomes the need for pre-classification, while offering strong transport of coarse particles made buoyant through their attachment to air bubbles. The paper explores the strong relationship between the solids transport to the overflow and the input gas flux, showing firstly the potential for significant mass rejection at the relatively low gas fluxes, and robust performance in terms of recovery across the full range of gas fluxes. Keywords: Flotation, inclined channels, coarse particle flotation, Reflux Classifier

Jan 1, 2020

By Rainer Antretter

The city of Garmisch-Partenkirchen in southern Germany is located at a main transit road to Tyrol in Austria and suffers of a very heavy traffic load. Therefore, the Kramertunnel as a by-pass tunnel is built to release/mitigate the traffic through the city centre. The 3,600 m long single tube road tunnel is designed with a parallel but smaller emergency tunnel and with cross passages, fitted with single- and doublesided emergency bays, a vent shaft, and an intermediate ceiling to separate fresh air supply from the road traffic. The tunnel, concrete lined along its entire length provided the challenge to find smart formwork solutions for quick set-up, repositioning, setup and pouring. Three particularly specific sections are discussed in this paper.

Jun 13, 2023

By Parkhurst D. H

It is shown that a differential colorimetric technique can be used as a routine method for the estimation of titanium in beach sands, and their ore dressing products. The method will tolerate the presence of most of the other elements usually found in beach sands. The accuracy is shown to be within the limits of ±0ò31 per cent for concentrates containing more than 95 per cent titanium dioxide and ±1 per cent for tailings containing 0ò2 per cent titanium dioxide. The method is described for use with a Hilger "Spekker" absorptiometer.

Jan 1, 1957

By D. W. Boydell

The response of reclaimed gold tailings to acid leaching was investigated in the laboratory, followed by a pilot-plant program in which the operations of CCD, CIX and SX were tested with plant feed material. These results formed the basis for the design of the extension to the existing uranium plant at Blyvooruitzicht Gold Mine, commissioned in July 1977. This circuit consists of slimes-dam reclamation by bucket-wheel excavator at a rate of 100,000 t solids per month, acid leaching in pachucas, a five-stage CCD washing section, two parallel C1X absorption columns and two elution columns, SX and an ADU precipitation section. Barren solution is recycled to the CCD section as wash and to the repulper at the slimes dam. The performance of the plant during the first year of operation is compared with the predictions on which the plant design was based. Rated capacity was achieved within three weeks of start-up at a nominal dissolved uranium recovery in the ion-exchange section of around 98%. Owing to recycle, the over-all recovery in the ion-exchange and solvent extraction sections is somewhat higher than this figure.

Jan 1, 1979

By Bradford F. Townsend, Marc R. Kritzer, Michael F. Roach, Dennis Ofiara

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of the authors and are not necessarily those of SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2008

By M. Syamujulu

In 1994, Nkana smelter commissioned a multimillion US Dollar Chilean Teniente converter (CT) in its operations in order to improve its smelting technological base. The main objective was to reduce the overall smelting energy costs and increase the sulphur capture for sulphuric acid production to support the company?s leaching operations at Nchanga tailings leach plant. A decade of CT operations have since ensued following its installation and start-up. This paper provides a technical and operational audit of the performance of the CT in the first 10 years of its operations at Nkana smelter.

Jan 1, 2005

Unlike traditional mining on land or ?dry? mining, relatively little is known of ?wet? or offshore mining within the industry. However, dredge mining has several benefits over dry mining, including high unit capacity, as well as lower operating and transport costs. IHC Merwede, a company with expertise in wet mining, is keen to raise awareness and help the industry move forward from dry to wet mining. The idea of mining offshore is not a new one. With global head grades declining, certain operations still have extensive resources of lower grade mineralization in their concession area. These operations require a lower cost, high volume solution for which dredge mining can provide an economic alternative. Interest in dredge mining has recently returned, and there is an increasing tendency to use dredge mining for the removal of overburden or the rehandling of tailing ponds.

Jan 1, 2013

By I. Iwasaki

In recent years the rapid depletion of high-grade iron ores and the demand by blast furnace operators for increasingly low-silica ores have stimulated interest in flotation studies of low-grade iron ores, such as wash-ore tailings and oxidized taconites. Four processes have been reported for the flotation separation of these iron ores--anionic and cationic collection of the iron oxides, cationic collection of siliceous gangue, and anionic collection of activated siliceous gangue (5).5/ The effectiveness of any one method, however, depends largely on the mineralogical composition and on the physical structure of the sample; hence, a comprehensive study of the floatability of the individual minerals occurring in these materials is essential. A review of the literature shows that the floatability of hematite and magnetite has been frequently investigated, whereas very little corresponding information is available for goethite, or for its more earthy form, limonite, both of which are abundant in the Mesabi and Cuyuna ores (19). The purpose of this investigation was to formulate general information on the floatability of goethite. Vacuum flotation, contact angle measurement, and simplified flotation tests using a modified Hallimond tube were used. The experimental results were correlated with the electrokinetic properties of goethite as determined by streaming potential measurement. The results were used to interpret the batch flotation tests made on an artificial mixture of quartz and goethite.

Jan 1, 1960

By Charles E. Locke

IN gathering material for this review the aid of the individual members of the Milling Committee was invoked and the assistance received is hereby most grate- fully acknowledged. The replies were much alike; almost everyone stated that in 1932 his operations had been cur- tailed or stopped entirely, that the only activity and progress were in milling gold ores, and that the Hadsel mill' looked like a coming machine in the crushing and grinding field. However, further inquiry and search have shown that the year was not quite so barren of developments as the foregoing statement would indicate.

Jan 1, 1933

By J. Finch, F. Rosenblum, McGill University

The self-heating of sulphides can be a major hazard in mining operations and concentrate handling, particularly during transportation and associated storage. Self-heating results from the oxidation of sulphide minerals and can vary from being insignificant to potentially hazardous to life and infrastructure. It is essential that there be a reliable test methodology that can categorize a given sulphide material as to its self-heating potential. By their nature, sulphide ores and concentrates are complex and variable mineral combinations making it difficult to predict their self-heating behavior a-priori based on mineralogy or with a simple "snapshot" test. Furthermore, self-heating behavior will depend on the state of oxidation of the sulphides as well as time, temperature and humidity. A review of available testing apparatuses and protocols that can be used to assess self-heating potential is presented. Each of these methodologies was examined in relation to its ability to predict the latent self-heating hazard of a sulphide material. Several of the methods were compared to illustrate their strengths and weakness. The results indicated that a number of the test protocols may produce false negative indications of self-heating potential, constituting an obvious concern to the industry.

Jan 1, 2014

By J. Palarski

Hard coal, mined in Silesia Region as well as in the eastern part of Poland, is a key national resource. In Polish underground coal industry, modern mining technologies have been successfully tested and used in the last 50 years. More than 98% of the coal produced underground is extracted by longwall mining method. Current underground coal mining expands into increasing depths. The use of conventional coal extraction methods ? room and pillar and longwall with caving - is becoming increasingly difficult. The coal mining is modifying existing methods and is testing innovative technologies. Backfill is an important component of modern underground mining operations. In Polish underground mines, backfill is recognized as an integral component for extraction of coal from greater depths in a densely populated environment. The modifying and innovative methods require the use of backfill or grouting of caving to provide structural support in underground excavations and to ensure that the mining operations are safe. Depending on the geological structure, mining conditions and environmental requirements there are several variations of longwall methods used in underground coal mining in Poland, in particular: longwall with caving, longwall with backfill, longwall with grouting of caving area. This paper will discuss the different components of an effective longwall production and filling process of caving area. The paper will give a overview of the current application of backfill technology, focusing on Polish coal mining operations. This paper will also briefly describe how backfill contributes to an innovative method ? underground coal gasification. The paper discusses specific requirements for fill materials and the technology of backfilling for underground coal gasification (UCG) operations and problems of implementation and correlation of backfill parameters with other processes that occur during thermal processing of coal.

Aug 1, 2013

By M. Bergerman

Sossego was the first Vale SAG mill operation to process copper-gold ore. It is located in Para state, south east of Amazon region in Brazil. The comminution circuit was designed to treat 41 000 metric tons per day comprising primary crushing, one 11.6 m SAG mill operating in closed configuration with cone crushers, followed by two 6.7 ball mills. In the first three years of continuous operation Vale investigated alternatives for obtained improved performance of the circuit by investigating operating conditions, mainly focusing on SAG mill. A number of actions were then implemented, which resulted in significant increase in overall production. Vale then decided to further assess the performance of the comminution circuit as a function of ore characteristics. A comprehensive ore characterization program was then conducted, together with the calibration of mathematical models on the basis of surveys carried out at the industrial circuit. The simulator was then used to predict the production level associated to each ore type, as well as to establish the optimized circuit configuration and tailored operating conditions. The ongoing validation program is planned to consolidate the selected strategy, as well as showing the benefits in adopting such indices in mine planning, as opposed to rather simplistic approaches. This paper describes in detail the main aspects of optimizing the industrial circuit performance, as well as the successful method for predicting the production as a function of ore characteristics.

Jan 1, 2014

By N. Tatalias, P. Ilunga, M. Lampi, J. Edwards, K. Valkama, M. Nicolle, D. Samal

"Developing a greenfield mining project is a complex exercise: doing so in an increasingly volatile, uncertain, and ambiguous global economy adds significantly to this complexity. In the context of an elevated cobalt price, this paper outlines the metallurgical and process development of the Mutoshi copper–cobalt project for copper cathode and cobalt hydroxide production in the Democratic Republic of Congo. Chemaf has a long production history on the Copperbelt, a region widely perceived to be tough to operate in. This history stretches back to 2001, during which time the company has developed two copper–cobalt processing facilities. The experience gained in the development and operation of these two facilities has been used extensively in the Mutoshi copper–cobalt project. The metallurgical test work, process design, and project delivery approach are presented. Additionally, the decisions taken to minimize risk and maximize upside to the project are discussed. IntroductionChemaf (Chemicals of Africa), a mining company located in Katanga province of the Democratic Republic of Congo (DRC), has been operating since 2001 with two major copper– cobalt processing facilities: the Usoke and Etoile plants. In 2016, Chemaf acquired the Mutoshi mine, which belonged to Gecamines and had been explored by Anvil Mining since 2004 under a joint venture with Gecamines. Chemaf appointed African Mining Consultants Ltd (AMC) to undertake a preliminary economical assessment, then develop a JORCcompliant Mineral Resource estimate and finally a full life-of mine feasibility study. Both a Mineral Reserve and Mineral Resource were developed and the final life-of-mine feasibility study is to be published shortly. A metallurgical test work programme was initiated and carried out by Chemaf’s research and development laboratory with assistance from the Chemaf process team. After completion of the initial test work, Chemaf developed a process design criteria document for a 20 kt/a copper cathode and 8 kt/a cobalt in hydroxide production plant, followed by a flow sheet and supporting METSIM mass balance. As the drilling progressed, the plant design capacity was revised to 16 kt/a cobalt production. The life of the mine at this production rate is over 40 years."

Nov 1, 2018

By L. Semushkina

Next generation flotation agents of KSK series for the concentration of complex copper-lead ores and the new ferromagnetic nanosized depressor of galena are introduced in this work. The feature of the KSK flotation agents is that they exhibit both frother and collector properties. KSK-6 can successfully substitute the widely used in Kazakhstani industry reagent ?-80 at the reduced consumption of butyl xanthate by 30 %. The new ferromagnetic nanosized depressor of galena, besides a low consumption rate of 100 g/t, also makes possible to exclude sodium sulfite (3-4 kg/t) and ferrous sulfate (5-6 kg/t) from the separation process, and receive high metal grade concentrates. Keywords: complex copper-lead ore, flotation agent, concentration method, ferromagnetic nanosized depressor

Sep 1, 2012

By S. Komar Kawatra, J. J. Carlson

"It is widely known that steel made from iron ore pellets high in phosphorus is brittle. Removal of phosphorus from iron ores such as hematite has proven to be difficult. The majority of research on phosphorus removal from hematite ores has been focused on flotation. The purpose of this study was to assess phosphorus distribution under current operations at an existing hematite concentrator and determine how efficient the plant is at removing phosphorus. Objectives included: (1) Perform a phosphorus balance at an operating plant to assess phosphorus distribution under current operations; (2) Determine phosphorus removal efficiency of each separating unit and (3) Perform a quantitative liberation analysis to determine max phosphorus removal by physical means. Liberation was quantitatively determined using wet high intensity magnetic separation (WHIMS) to separate iron ore from liberated apatite (and other nonmagnetic compounds).It was observed that 61.2% of the total phosphorus entering Plant F was rejected during current operations. The desliming process was the most efficient step at removing phosphorus (45.1% P removed), whereas the flotation step was much less effective (16.1% P removed). Liberation analyses indicated that the deslime thickener may have been more efficient at removing phosphorus than the flotation circuit due to the greater abundance of liberated phosphorus in the deslime thickener feed. The scavenger returns stream was identified as having a high concentration of phosphorus and a possible point of phosphorus removal. However, liberation analyses indicated that only 32.4% of the total phosphorus in the stream was liberated. Grinding the scavenger returns to 80% passing 5.2 µm increased the amount of liberated phosphorus in the stream to 70.4%."

Jan 1, 2014

By V Kumar, A S. Venkatesh, R K. Upadhya

The enormous iron ore deposits of eastern India are part of the volcano-sedimentary basins containing iron and to some extent manganese deposits that belong to the Iron Ore Group (IOG) of Archaean Singhbhum Craton, occurring as western and eastern limbs of a broad synclinorium. The eastern iron basin contains typically huge amounts of blue dust and powdery ores. There is a remarkable difference between the western flank ores and the eastern flank ores and the present study is part of the eastern flank ores from Noamundi. Demand for sintered fines as blast furnace feed coupled with the higher export price for lumpy ores that produce enormous amounts of fines during processing has created a situation whereby both primary and secondary fines, such as classifier fines, are being increasingly used as sintered feed for blast furnace. Systematic mineralogical and geochemical characterisation indicates that in many cases the ROM and classifier fines have to be processed to increase their Fe content and at the same time reduce their Al, Si and P contents. The fines which are already at micron sizes are amenable for beneficiation using the Mozley mineral separator and sink float test. It was observed that beneficiation was better and significantly greater by the sink float method than the Mozley mineral separator. Mineralogical and chemical studies of the fines reveal that around 80 per cent of alumina bearing minerals (gibbsite, clay and silicates) are present in the liberated form. Microscopic studies confirmed that the iron minerals are well liberated by controlled grinding to -300 mesh sizes with the beneficiation of iron ore fines and low-grade ores carried out using the Mozley mineral separator and sink float test. Beneficiation using the Mozley mineral separator increased the grade of concentrate with increasing flow rate of water as well as increase in amplitude of oscillation of the tray, but not very significantly with the increase in slope of the tray. In this method, though, iron concentration improved from 47 to 63 per cent with a recovery of around 67 per cent. It is not suitable for industry scale operation as only a small quantity of ores can be handled at a time. Beneficiation using the sink float test produced a better result with the Fe content increasing from 47 - 49 per cent to 66 - 68 per cent with a recovery of approximately 58 per cent. Initial feed Al2O3, SiO2 and Fe contents of 9.85 per cent, 15.3 per cent and 49.8 per cent respectively were beneficiated to 2.13 per cent Al2O3, 1.5 per cent SiO2 and 67.5 per cent Fe in the concentrate, with a recovery of 54.1 per cent. In contrast, using the Mozley table resulted in beneficiable contents 66.3 per cent Fe, 3.01 per cent alumina and 2.05 per cent silica. The combined alumina and silica content for the Mozley Table was >5 per cent, which exceeds the industry requirement of

Jan 1, 2005

By Vanessa M. Torres

Cia. Vale do Rio Doce is currently developing Niquel do Vermelho Project. The laterite deposit is located at Carajas Mineral Province at less than 15 km from Sossego Copper Project, scheduled for start-up in 2004. The available infrastructure, includes paved roads, large capacity railroad and port complex owned by CVRD, power supply and good quality water. The project was evaluated in the past for ferronickel production. In the late 1990s, CVRD switched its attention to investigating the usage of pressure acid leaching. The combination of good metallurgical behaviour for pressure acid leach (PAL) process route with reasonable mineable grades, and existing infrastructure justified the start of engineering studies in 2002. The project approach at the engineering phase is based on the dual objective of minimizing risks while maximizing project profitability and value. CVRD is currently completing the Niquel do Vermelho prefeasibility study. This paper outlines the main outcomes of the study and future perspectives for the project.

Jan 1, 2004

By I. D. Reznik

Results of thermodynamic computations have been presented for reactions occurring in the process of segregation roasting of oxide nickel ores to describe more accurately the mechanism of the process. Under conditions of laboratory-scale roasting in combination with close-circuit flotation flow-sheets and magnetic separation, a recovery of 80-82% of nickel into 8 to 10% Ni concentrate and a recovery of up to 66% of cobalt was achieved. Process conditions have been selected for processing of both high-iron and high-magnesium ores. The feasibility of conversion of 94-98% of nickel and cobalt into solution by oxidizing pressure leaching with sulfuric acid has been demonstrated. It has been substantiated that it is reasonable to introduce double-stage segregation roasting.

Jan 1, 2003

By S. Ajima

The Naoshima Smelter and Refinery is the most important copper operation of Mitsubishi Materials Corporation. There are a Mitsubishi Continuous smelter and a conventional type of copper tankhouse. The continuous smelter with 240,000 mtpy of anode production was commissioned in May 19914 replacing two existing smelters, i.e an original Mitsubishi Process line and a conventional reverberatory furnace line. In July 1992, the copper tankhouae was expanded for the purpose to close the gap of production capacity between the smelter and the tankhouse. The cathode production capacity was increased from 13,800 to 15,800 mtpm. By these plant modifications, the distribution of minor elements was significantly changed and the impurities load is getting on increase reflecting recent shortage of clean copper concentrates supply. The paper discusses the distribution of minor elements and the impurity control strategy at the smelter end the refinery.

Jan 1, 1995

By A. Mezei

Samples of cobalt and bismuth concentrates produced from the NICO deposit in Northwest Territories were subjected to a comprehensive metallurgical testwork consisting of: pressure oxidation, ferric chloride leach and carbon in leach, to recover the cobalt, bismuth and gold, respectively. A specific testwork program was designed to allow for the optimization of process parameters under multiple restrictive criteria. The overall objective was to establish leaching sequences that could produce acceptable recoveries while generating environmentally disposable residues as well as solutions suitable for further processing. The recoveries for the leaching stage, under the optimum conditions, were 97% for cobalt and 95% for gold, in the case of the cobalt concentrate. The bismuth concentrate produced recoveries of 99% for bismuth, 99% for cobalt and 97% for gold, respectively

Jan 1, 1999