peru 3d character xmt 2012

7/27/2019 Peru 3D Character XMT 2012

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3D Characterization, Analysis and

Simulation of Multiphase Particulate

Systems in Mineral Processing Using X-ray Computed Tomography

J.D. Miller

Chair and Ivor Thomas Distinguished Professor

Department of Metallurgical EngineeringCollege of Mines and Earth Sciences

University of Utah

Lima, Peru, October 2012


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Development of X-ray Tomography

Instrumentation Development Year Resolution

Milli Scanner Translate/Rotate, 1st - 6th

generation, Medical field

1971- ~ 1 mm

Micro Scanner Algorithm,

Microfocus X-ray source

Cone Beam Geometry

1984

1995- ~10 mm

HR Micro

Scanner

Improved detector,

Advanced X-ray optics

2000s ~1 mm

Nano Scanner Monochromatic source,

Higher photon flux

2010s ~50 nm


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X-Ray Tube

Imaging

Detector

X-Ray Beam

Specimen

Positioning

Stage

Cone Beam MicroCT - Installed 2000


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Early Applications of X-ray

Tomography in Mineral Processing

1987 Sedimentation and Flocculation Somasundaran et al.

Powder Technology

1990 Applications in Mineral Processing Miller, Lin, Cortes

Miner. Process. &Extrac. Metal. Review

1991 Coal Washability Lin et al.

Coal Preparation

1996 Swirl Flow in ASH Flotation Das and Miller,IJMP

1996 Cone Beam Microtomography for

3D Mineral Liberation Analysis

Lin and Miller,

IJMP


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Research Group at the University of Utah,~2008


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Multiphase Particulate Systems

X-ray Computed Tomography (CT)

The analysis of individual particles

with spatial resolution in 3D has been

difficult. Only recently have we beenable to spatially resolve particle size,

shape, and composition in 3D using x-

ray tomography.


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Projection

3D View

Slice

Views

Conventional


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Phase Differentiation by X-Ray CT

Mineral

Name

Formula Mass Density

(g/cm3)m (cm

-1)

Quartz

Calcite

MagnetiteRutile

SiO2CaCO3

Fe3O4TiO2

2.65

2.71

5.204.25

0.448

0.530

1.6200.955

2.3

8.3

.E

bZam

i

ii ZfZ8.38.3


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Particle Properties

Geometric Features - Size,Shape, Surface Area

Density, Porosity, DamageCompositionExposure,

Texture, Liberation

Pore Network Structures


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High Resolution XMT-Installed 2009

Source Detector

Sample Stage


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High Resolution X-ray Micro CT

Analysis of packed particle beds containing

as many as 60,000 particles can be

accomplished in less than 3 hours withspecial software to establish the 3D

characteristics of each particle in the

sample population. Such data corresponds

to 1 Gbyte of tomographic information.


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Particle Separation (Watershed)Rougher Feed (45x25 mm)

HRXMT Watershed Segmentation


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Critical Factors in the Development of High

Resolution X-ray Tomography Systems

X-ray Source / Optics

Detector Sensitivity

Computer Capacity


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Mineral Processing Applications

Comminution

Exposure/Liberation

Heap Leaching


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Comminution

Damage of Particles in Specified Size ClassFraction of particles with cracks

Crack density

Specific crack surface area Grain Boundary Fracture

Increased liberation

Loss of interfacial area


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Damage-Isolation of Crack Surfaces

(Copper Ore , 2.00x0.85 mm)

Green

surface Pink

cracks + pores


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Percent of Damaged Particles (4.75x2.00 mm) for

Different Crushing Methods (voxel resolution = 40 mm)Crushing

Method

Extent of Damage

(% of Particles Cracked)

Oxide Copper

Ore

Sulfide Copper

Ore

Feed 14 20

Jaw 14 23

Low HPGR 37 51

Medium HPGR 44 69

High HPGR 79 84


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Nano CT Image-Copper Sulfide Ore(0.15x0.038 mm, voxel resolution = 130 nm)

Crack width = 0.29 mm


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Grain Boundary Fracture

Conservation of interfacial area after crushing is

indicative of trans-granular random breakage. On

the other hand, if interfacial area is diminished

after breakage some degree of preferential grain

boundary fracture has occurred. For completeliberation of all grains after crushing the

interfacial area goes to zero. Thus the interfacial

area criterion is an important metric to assess the

significance of preferential grain boundaryfracture for different breakage conditions.


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Volume : 8.24 mm3

Interfacial Area :

0.2522 mm2/mm3

Grain Boundary Fracture

Compression

+500 mm 500x350 mm 350x250 mm 250x180 mm 180x125 mm


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Specific Interfacial Area Ratio vs Energy

Dissipation Rate

0.5

0.6

0.7

0.8

0.9

1.0

0.0E+00 2.0E-05 4.0E-05 6.0E-05 8.0E-05

Power (W)

S

pecificinterfacia

larearatio

(mm

2/mm

3)

Energy Dissipation Rate (W)

Garcia, Lin, Miller, Minerals Engineering 22 (2009) 236

243


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Comminution

Exposure/Liberation

Heap Leaching


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Liberation Limited Grade/Recovery Curves

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Recovery (%)

Grade(%)

Complete Liberation

NoLiberation

Increased

Liberation

(Each Particle of Uniform Composition, Grade =20%)


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Liberation Limited Grade/Recovery Curves


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Texture Analysis and Flotation Kinetics


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Comminution

Exposure/Liberation

Heap Leaching


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Heap Leaching

Zaldvar, Chile

LeachSoution

HostRock

Copper

Mineral

Optimization of the Heap

Leaching recoveries requires abetter understanding of the

variables involved (exposure,

permeability, kinetics, etc.)


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Heap Leaching Research

Mineral

Exposure

Rate of

Chemical

Reactions

Fluid Flow in

Packed

Particle Beds

PSD


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Mineral Exposure Analysis


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Exposure vs Particle Size

Miller et al. Int. J. Miner. Process. 72 (2003) 331340


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Predicted Copper Recovery from Exposure Analysis

vs. Results from 1.5 m Column Experiments

Miller et al. Int. J. Miner. Process. 72 (2003) 331

340

Ch i Hi h D i Mi l G i


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Changes in High Density Mineral Grains

Lin, Garcia, J.D. Miller Symposium, 2005


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Leaching - Column Tests

Input

Output


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CT Analysis of Packed Column

Si l ti f Fl Th h P k d C l


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Simulation of Flow Through Packed Column

Using Lattice Boltzmann Model

Before Column Leaching (full column)

Sim lation of Flo Thro gh Packed Col mn


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Simulation of Flow Through Packed Column

Using Lattice Boltzmann Model

After Column Leaching (full column)


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Summary

Advanced instrumentation and accompanying

software for x-ray tomography analysis haveallowed for a more complete description of

multiphase particulate systems so important to

achieve significant improvements in mineral

processing technology.

As a consequence, appropriate education and

training of young scientists and engineers in this

area is necessary in order to prepare current studentswith advanced skills for future development and

applications in our profession.

peru 3d character xmt 2012

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