concentrators.
RECOVERY OF VALUES FROM A PORPHORY 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 @ ereiz. com
Phone:( 540) 230-7112 Email: Luttrell @ vt. edu ABSTRACT
KEYWORDS
Primary Grinding
Circuit Feed
Split-Feed Sulfide Flotation
Primary Classifiers
Secondary Classifiers
Classifiers
HydroFloat
Regrind
Regrind Mill
Conventional Rougher
Conventional Scavenger
Final Column
Concentrate Cleaner
Tails
Coarse Particle Recovery
Changes Everything!
Particles approximately 850 microns
HydroFloat Separator
Recovers virtually all particles which exhibit greater than 1 % hydrophobic surface expression
Overflow Coarse Mineral
Air
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 Recovery using EFD’ s HydroFloat Separator can:
• Increase mill throughput by as much as 15-20 %
• Reduce energy & media consumption
• Produce a coarse tailing stream
Underflow Coarse Tails
Rejects only those particles that have no hydrophobic surface expression
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
Gerald H. Luttrell Mining & Minerals Engineering, 100 Holden Hall Virginia Tech, Blacksburg, VA 24061 USA Phone:( 540) 230-7112 Email: Luttrell @ vt. edu
ABSTRACT
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. KEYWORDS Coarse Particle Flotation, X-Ray Computed Tomography, Liberation / Exposure, HydroFloat Separator
Jaisen Hilsen and Gerald H. Luttrell Mining & Minerals Engineering, 100 Holden Hall, Virginia Tech, Blacksburg, VA 24061 USA
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 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 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. A sample photograph of coarse middling particles recovered by this technology is shown in Figure 1. Similarly, for ultrafine particles, a new highintensity 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 were previously lost as waste due to low capture efficiencies. 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
Figure 1 – Photograph of coarse middling particles recovered as froth concentrate from a previously discarded tailing stream using the HydroFloat technology.
Coarse Particle Flotation, Fine Particle Flotation, HydroFloat, StackCell
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
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