Gerald H. Luttrell
ABSTRACT
KEYWORDS
RTICLE HNOLOGY
es
0-200 microns due ions, a novel fluidize ally for the purpose minerals. Over the several full-scale u sulphide-based test w ues at a grind size th, X-ray microtomog ace exposure necess indicate that both p flotation from a low ons was achieved p ides detailed 3D an t of surface area undamental issues operations.
puted tomography
Exposure, HydroFl
RECOVERY OF VALUES FROM A PORPHORY RY COPPER TAILINGS STREAM
Michael J. Mankosa, Jaisen N. Kohmuench, Lance Christodoulou Eriez Flotation Division, 2200 Asbury Road, Erie, PA 16506 USA Phone:( 814) 835-6000 Email: mmankosa mankosa @ ereiz. com
Jaisen Hilsen and Gerald H. Luttrell Mining & Minerals Engineering, 100 Holden Hall, Virginia Tech, Blacksburg, VA 24061 USA Phone:( 540) 230-7112 Email: Luttrell @ vt. edu
ABSTRACT
The efficiency of the froth flotation process has long been known to be strongly dependent on particle size. For sulfide minerals, good recoveries are typically achieved in industrial flotation circuits for particles in the 10 to 200 micron size range. Particles outside this critical size are typically lost in the tailings streams rejected by industrial operations due to inherent constraints associated with the physical interactions that occur in the pulp and froth phases of conventional flotation equipment. In response to these limitations, a series of experimental studies were conducted to determine whether particles previously lost as tailings could be economically recovered using a suite of novel flotation on technologies developed for the upgrading of ultracoarse and ultrafine particles in the industrial minerals industry. For the case of ultracoarse particles, a fluidized-bed flotation system called the HydroFloat separator ator was tested. The data obtained using this novel flotation device in both laboratory and pilot-scale trials showed that good recoveries of previously lost sulfide values up to 0.7 mm in diameter could be achieved ed. A sample photograph of coarse middling particles recovered by this technology is shown in Figure 1. Similarly, for ultrafine particles, a new intensity flotation system known as the StackCell was tested. This technology, which utilizes high-shear
high-energy contacting of slurry and gas, was capable of recovering valuable ultrafine sulfide slimes that
highwere previously lost as waste due to low capture efficiencies es. The objectives of this article are( i) to describe the unique operating principles of these two advanced flotation technologies and associated ancillary classification equipment,( ii) to present experimental test data showing the metallurgical benefits of this approach for upgrading coarse and fine sulfide minerals, and( iii) to provide a generic cost-benefit analysis of the proposed system for upgrading tailing streams historically rejected by sulfide mineral concentrators.
Figure 1 – Photograph of coarse middling particles recovered as froth concentrate from a previously discarded tailing stream using the HydroFloat technology.
KEYWORDS
Coarse Particle Flotation, Fine Particle Flotation, HydroFloat, StackCell
Circuit Feed
Split-Feed
Sulfide Flotation
Primary Classifiers
Primary Grinding
Secondary Classifiers
HydroFloat
Regrind Classifiers
Regrind Mill
Conventional Rougher
Column Cleaner
Final Concentrate
Conventional Scavenger
Tails
POWER FOR MINES
Turbines sold five CX501-KB7 generator sets to Genser Energy Ghana. Each incorporates a Siemens 501-KB7 gas turbine. The KB7s will run on vapourised propane with fuel supply and treatment also part of the Genser contract with Gold Fields.
Genser’ s expertise in running turbines on propane opens up a large potential market in Africa for Centrax where pipeline natural gas is not available and liquid fuel is not economically viable. Peter Ward, Centrax’ s Sales and Marketing Manager commented:“ this order further strengthens Centrax’ s position in West Africa and follows on from the sale of a CX501-KB7 to Cometstar, Nigeria.”
ACTOM Turbo Machines demonstrated its ability to provide complete electro-mechanical solutions with the installation of 150 MW turbo generator sets for First Quantum Minerals’ Cobre Panama new large open-pit copper mining operation in the Donoso District, Republic of Panama.
Securing what was the first international contract to have been won by ACTOM Turbo Machines can be attributed in part to the longstanding relationship between Marthinusen & Coutts, also an ACTOM division, and the customer, as well as its established track record of successes on previous projects for this mining company. It is also noteworthy that this contract was secured against tough international
competition. ACTOM was contracted for the mechanical installation of two Skoda Doosan( Czech Republic) 150 MW turbo generator sets, which each comprised of an integrated high pressure and intermediate-pressure turbine, a low pressure turbine, a Siemens generator, a radial condenser, and auxiliaries.
Richard Botton, Marthinusen & Coutts’ s CEO as well as ACTOM Turbo Machines’ Managing Director, Chris Bezuidenhout and eventual Site Manager John Squire, took several trips to Panama to review the scope of work, drawings and site conditions to compile the proposal, which resulted in Marthinusen & Coutts’ first international installation.
ACTOM was responsible for the installation of the centreline of the turbo generator sets, which started with the inspection of the civil works, followed by the systematic assembly of the turbo generator’ s in the form of transportable components and sub-assemblies. As the original equipment manufacturer( OEM) only supplied an Installation Quality Controller, ACTOM Turbo
The turbine generator set for Cobre Panama showing the Siemens 150 MW generator and the low pressure and high pressure Skoda Doosan turbine set
Machines installation crew’ s expertise was pivotal to the successful installation of the turbo generator sets.
The tropical region’ s high rainfall and open building also placed extreme strain on the schedule. The turbo generators’ house was largely open, and only equipped with a 40 t overhead crane, whereas the larger assemblies and components, such as the HP-IP double turbine and the LP turbine components weighed 125 and 161 t, respectively.
Weather permitting, ACTOM made use of crawler cranes to install these larger
Recovers virtually all particles which exhibit greater than 1 % hydrophobic surface expression
Rejects only those particles that have no hydrophobic surface expression
Particles approximately 850 microns
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Overflow Coarse Mineral
Air
Underflow Coarse Tails
THE SIGNIFICANCE OF EXPOSED GRAIN SURFACE AREA IN COARSE PARTICLE FLOTATION OF LOW-GRADE COPPER ORE WITH THE HYDROFLOAT TECHNOLOGY
Jan D. Miller, C. L. Lin and Yan Wang Department of Metallurgical Engineering, College of Mines and Earth Sciences University of Utah, Salt Lake City, UT 84112 USA Phone: 801-581-5160 Email: Jan. Miller @ utah. edu
Michael J. Mankosa and Jaisen N. Kohmuench Eriez Flotation Division, 2200 Asbury Road, Erie, PA 16506 USA Phone:( 814) 835-6000 Email: mmankosa @ ereiz. com
Mining & Minerals Engineering, 100 Holden Hall Virginia Tech, Blacksburg, VA 24061 USA Phone:( 540) 230-7112 Email: Luttrell @ vt. edu
Conventional flotation machines are typically limited to a particle topsize of 150-200 microns due to inherent constraints created by the pulp and froth phases. To overcome these limitations, a novel fluidizedbed flotation system called the HydroFloat Separator has been developed specifically for the purpose of floating coarse particles containing only minute amounts of exposed hydrophobic minerals. Over the last decade, this technology has been successfully applied to industrial minerals with several full-scale units installed to recover particles up to and exceeding 3 mm diameter. More recently, sulphide-based test work has shown that this novel device is also capable of recovering metalliferous values at a grind size that is much coarser than currently used in industrial concentrators. In the current study, X-ray microtomography( Figure 1) was used to experimentally quantify the degree of hydrophobic surface exposure necessary to recover particles of different sizes using the HydroFloat technology. The data indicate that both particle mass and surface area of exposed grains are critical factors in coarse particle flotation from a low grade copper ore. Excellent recovery for multiphase particles as large as 850 microns was achieved provided there was sufficient surface exposure of locked sulfide grains. This article provides detailed 3D analysis of flotation products using X-ray microtomography, which defines the extent of surface area exposure necessary for recovery of each size class fed to the HydroFloat Separator. Fundamental issues of bubble attachment are also discussed as well as process strategies for improved plant operations.
Figure 1 – Analysis of locked particles by X-ray computed tomography.
Coarse Particle Flotation, X-Ray Computed Tomography, Liberation / Exposure, HydroFloat Separator
This Changes Everything!
EFD’ s HydroFloat ™ Separator radically improves the traditional sulfide processing circuit through Coarse Particle Flotation. Unlike conventional flotation, the HydroFloat Separator recovers particles as large as 800 microns with as little as 1 % mineral surface expression. By rejecting the balance as“ coarse” tailings, much of the recirculating load is eliminated, thus greatly increasing mill capacity … with NO loss in mineral recovery!
Coarse Particle Flotation using EFD’ s HydroFloat Separator can:
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SPLIT-FEED CIRCUIT DESIGN FOR PRIMARY SULFIDE RECOVERY
Michael J. Mankosa and Jaisen N. Kohmuench Eriez Flotation Division, 2200 Asbury Road, Erie, PA 16506 USA Phone:( 814) 835-6000 Email: mmankosa @ ereiz. com
Gerald H. Luttrell Mining & Minerals Engineering, 100 Holden Hall, Virginia Tech, Blacksburg, VA 24061 USA Phone:( 540) 230-7112 Email: Luttrell @ vt. edu
John A. Herbst Mining Engineering, 365A Mineral Resources Building West Virginia University, Morgantown, WV 26506 Phone:( 304) 293-7680 Email: jaherbst @ mail. wvu. edu
ABSTRACT
A new generation of advanced flotation technologies has recently been developed and commercially deployed during in the industrial minerals industry. One such technology is the HydroFloat separator. This unique fluidized-bed flotation system has dramatically increased the upper particle size limit that can be successfully treated by froth flotation. Recent studies conducted using laboratory, bench-scale and pilotscale equipment indicate that this technology can also be used to float coarse sulfide middlings that cannot be recovered by conventional flotation machines. Data collected from pilot-scale tests conducted at a base metal concentrator indicate that this technology can float composite middlings as large as 700 microns containing as little as 5 % hydrophobic mineral. As such, the crossover of this technology into the base metals industry has the potential to offer many advantages for recovery, selectivity and capacity through the use of split-feed circuitry. The split-feed concept, which is often used for upgrading industrial minerals, involves segregation of the feed into more than one size class followed by separate upgrading of each class using separators / reagents specifically optimized for that particular size class. An example of a split-feed flowsheet for sulfide flotation that includes coarse and fine processing circuits is provided in Figure 1. In this case, a coarser grind size and correspondingly higher mill throughput can be accommodated via the use of the coarse particle flotation equipment. The objectives of this article are( i) to introduce the key features of the split-feed circuitry incorporating the HydroFloat technology,( ii) to present experimental test data showing the metallurgical benefits of this processing scheme, and( iii) to provide simulations of the split-feed circuitry illustrating the increased milling capacity that may be attained by this approach.
Figure 1 – Flowsheet for a split-feed sulfide flotation circuit. KEYWORDS
Circuit Design, Circuit Simulation, Split-Feed Flotation, Coarse Particle Flotation
For more details download these White Papers at www. EriezFlotation. com
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