john visser, mineral engineering technical services pty ltd: a comparison of jigging and dense media...

> M i n e r a l P r o c e s s i n g > E n g i n e e r i n g D e s i g n > T r a i n i n g > S p e c i a l i s t S e r v i c e s > RESOURCE PROJECTS > TECHNOLOGY > INTEGRATED SERVICES > Mineral Processing > Engineering Design > Training > Specialist Services

Ph: +61 8 9421 9000

Fax: +61 8 9325 8311

Email: [email protected]

Web: www.metsengineering.com

PO Box 3211, ST GEORGES TCE, WA 6832

AUSTRALIA

4th Annual FeTech Conference 2013

Criteria for Selecting a Jig or DMS

Presented by John Visser

Mineral Engineering Technical Services

> RESOURCE PROJECTS > TECHNOLOGY > INTEGRATED SERVICES > Mineral Processing > Engineering Design > Training > Specialist Services

> DISCLAIMER With respect to all the information contained herein, neither Mineral Engineering Technical Services Pty Ltd, nor any officer, servant, employee, agent or consultant thereof make any representations or give any warranties, expressed or implied, as to the accuracy, reliability or completeness of the information contained herein, including but not limited to opinions, information or advice which may be provided to users of the document. No responsibility is

accepted to users of this document for any consequence of relying on the contents hereof.

> COPYRIGHT © Passing of this document to a third party, duplication or re-use of this document, in whole or part, electronically or otherwise, is not permitted without the expressed written consent of Mineral Engineering Technical Services Pty Ltd.

> ACKNOWLEDGEMENTS This document is a dynamic record of the knowledge and experience of personnel at Mineral Engineering Technical Services. As such it has been built upon over the years and is a collaborative effort by all those involved. We are thankful for the material supplied by and referenced from various equipment manufacturers, vendors, industry research and project

partners.


Key Attributes

> Working globally since 1988

> Dynamic and innovative niche consultancy

> Dedicated team providing customised service

> Specialist in Mineral Processing & Engineering Projects

> Unique solution finder

Pragmatic, efficient, complete engineering through quality, personalised & exceptional service delivery


Overview

> Introduction

> Criteria for selection

> Jig Setup

> DMS Setup

> Case studies

> Capex and Opex


Introduction


Criteria For Selection


Criteria for selection

Criteria Jigs DMS

Particle size Narrower sizing Broader sizing

Density cut No restriction Max limit of 3.8

Density difference

between float and sinks

> 1.0 0.5 to 0.8

Efficiency Less sharp Sharper

Efficiency Dependant on small size

Near density material Less of a problem

More of a problem

Yield and recovery Less optimisation Better optimisation

Tailings grades Higher Lower

Seperation Density Density

Capex Higher Lower

Opex Lower Higher


Separation of Iron Ores

Iron Oxides

(Hematite)

Magnetite

Coarse (-32+8mm) DMS

Jigging

Cobbing

LIMS Medium (-8+1mm)

Fine (-1mm+212/75µm) Spirals

WHIMS

Flotation

LIMS

Flotation Slimes (-212µm)


Efficiency comparison

0.00

20.00

40.00

60.00

80.00

100.00

120.00

F 2.7 2.7 - 2.85 2.85 - 3 3 - 3.15 3.15 - 3.3 3.3 - 3.45 3.45 - 3.6 3.6 - 3.75 3.75 - 3.9 3.9 - 4.05 4.05 - 4.2 S 4.2

DMS vs. Jig partition curve

DMS

Jig (Interpolated)


JIG SETUP


Gravity Separation Performance

> Concentration Criterion = SG of heavy mineral − SG of fluidSG of light mineral − SG of fluid

Concentration Criterion (CC) Gravity Separation

CC>2.5 Easy down to 75 µm

1.75<CC<2.5 Possible down to 150 µm

1.5<CC<1.75 Possible down to 1.7 mm

1.25<CC<1.5 Possible down to 6.35 mm

CC<1.25 Impossible at any size


Jigging

> Size classes for iron ore

― – 32 +8mm

― – 8 +3mm

― – 3 +1mm

> Size classes for coal

― – 100 + 35mm

― 35 + 10mm

― – 10 + 3mm

> Capacity Batak Style Jig

― 65 t/h per meter width of jig to max of 4 m wide jig


Jigging Operation

> The oscillating motion causes pulsations that will dilate the bed of

material

> This makes the particles settle as the larger and denser particles forming

the lower layers with the finer and lighter particles on the top

> During the suction stroke, differential initial acceleration occurs followed

by hindered settling and finally consolidation trickling

Start Dilation

Differential

Initial

acceleration Hindered

settling

Consolidated

trickling


Jigging Action


Jig Variations


Under bed (Batac®) pulsed machines

> Examples

> Alljig from Allmineral

> Batac® from Humboldt Wedag

> Apic jigs from Bateman


AllJig

> Side pulsed or under bed pulsed machines


Slimes Dam

Lumpy Product

Fines Product

2 x Double deck

-80 mm

554 tph

-8 +. 5

188 tph

3718 m3ph

1400 m3ph

849 m3ph

1592 m3ph 1296 m3ph

-8 + . 5

129 tph

-32 + 8

80 tph

10 tph

1382 m3ph

2 x Single deck

-32 +8

264 tph

-8 +.5

51 tph

-32 +8

182 tph

+ 32 mm

231 tph

Crusher

Discard

407 tph

-80 mm

785 tph

Lumpy

Fines

From W &S 2960 m3ph

Jig Plant

Preparation

Plant

Water Reclamation Plant

Jig Process Flowsheet


DMS SETUP


DMS described

> Dense Media Separation (DMS) is a physical separation technology

which relies on the difference in material densities to separate

different materials

> The mixed solids are placed in a liquid denser than one and less

dense than others

> The denser material sinks while the less dense material floats

> DMS is the most straight forward technique for separating particles

based on their densities

> Also known as Heavy Media Separation (HMS)


DMS Medium

> Heavy Liquids

> Response of a given feed to a DMS process and be accurately

established in a laboratory by testing with various heavy liquids

Name Specific Gravity, 25oC

Methylene iodide 3.33

Tetrabromoethane 2.96

Bromoform 2.86

Tribromoethane 2.61

Methylene bromide 2.48

Ethylene dibromide 2.17

Methylene chlorobromide 1.92

Pentachlorethane 1.67

Carbon tetrachloride 1.59

Trichloroethylene 1.46

Ethylene dichloride 1.26

Liquids Used to Test Feeds


DMS Medium

> Heavy Liquids

> Aim is to separate the ore samples into a series of fractions

according to density

> May be used to assess the efficiency of an existing dense

medium circuit

> Heavy liquids give off toxic fumes and must be used with proper

ventilation

> The use of pure liquids has not been found to be practicable on

a commercial scale

> Industrial processes employ finely ground solids suspended in

water


DMS Medium

> Finely ground or atomised Ferro Silicon (FeSi) and water are

commonly used as the heavy media

> Specific gravity is adjusted by addition or removal of FeSi

> Would not work where solids have similar densities, nor those that

are soluble in the fluid media

> Magnetic materials must be removed before this step

> Separated materials may have to be dried for further processing


DMS Medium

> FeSi SG: 6.7-6.9

> Milled FeSi produced in different size ranges

– 30-95% –45µm

– Coarser, low viscosity grades achieve medium densities of up

to 3.3

> Atomised FeSi

– More spherical particles

– Medium is of lower viscosity

– Used to achieve densities as high as 4


DMS Medium Ferrosilicon


Gravity DMS – Drum Separator

> Drum Separator

> Side view



> Drum Separator

> End view



WEMCO® Heavy Media Drum Separator


Centrifugal DMS – DSM Cyclone

> Dutch State Mines (DSM) Cyclone Separator

> Used for finer feeds, 0.04 to 0.0005 m

> Separation is made by the action of centrifugal and centripetal forces.

> The heavier portion of the feed leaves the cyclone at the apex opening (5), and the lighter portion leaves at the overflow top orifice


Centrifugal DMS – DSM Cyclone


Dense Media Separation on Iron Ore

> Cut SG of 3.6-3.8

> Not considered at SG 4 due to impact of high FeSi viscosity

> Ferrosilicon is used in water atomised, gas atomised or finely

milled forms


Typical DMS Flowsheet


DMS PFD


Case Studies


DMS results: Operation A

> The operation’s product grades are – > 65% Fe

– Density cut point for achieving grade is considered to be 4.2

– So, no chance

Description Weight (g) Weight (%) Fe (%)

+3.8sg 7.3 3.8 61.54

-3.8+3.6sg 28.6 15.0 57.11

-3.6+3.3sg 146.0 76.9 55.95

-3.3sg 4.0 2.1 52.19

Total (+1.18mm) 185.9 97.8 56.27

-1.18mm 4.1 2.2 46.47

Calculated Head 190.0 100.0 56.05

Head Assay 55.67


Jig results: Operation A

> Notice grade is achieved

> Notice also the mass yield

Lump product Pilot plant – results for 11 test runs

Product – (32-62mm)

Weight (%) % Fe Grade Fe Recovery (%)

Feed Run 1 100 60.1 101.2

Conc. Run 1 85 65.4 92.5

Reject Run 1 15 34.6 8.6

Feed Run 4 100 62.1 99.3

Conc Run 4 86.8 66.5 93

Reject Run 4 13.2 29.7 6.3

Feed Run 7 100 59.7 99.9

Conc. Run 7 85.4 65.3 93.4

Reject Run 14.6 26.4 6.5

Jigging Test Runs


Jig results: Operation B

Fe Grade % Pilot plant – overall results

Laboratory tests - average

Product (32-6mm)

Conc 63.4 63.1

Rejects 53.2 53.5

Feed 58.8 60.2

Products (6-1mm)

Conc 63.2 63.1

Rejects 52.8 53.2

Feed 59.6 59.9

Design % Actual %

Product (32-6mm)

Weight Fe Grade %

Fe Recovery %

Weight Fe Grade %

Fe Recovery %

Conc. 67 63.5 70.1 72.2 63.5 74.8

Mids. 1320 57.3 18.9 19.4 58.8 18.6

Rejects 10013 47 10.1 8.4 47.7 6.5

Feed 100 60.7 100 61.3

Product (6-1mm)

Weight Fe Grade %

Fe Recovery %

Weight Fe Grade %

Fe Recovery %

Conc. 63.4 63.5 66.3 64.1 63.4 66.3

Mids. 25.6 61.6 26 28.1 58.6 26.9

Feed 11 47 8.5 7.8 44.7 5.7


Costing

Capex and Opex


Process Design Criteria

> Haematite

> Plant throughput: 900 tph

> Minus 2 mm rejected

> Lump/fines split 60/40 = 540/260 t/h

> Jig unit: lump and fines: under bed pulsed: Batac®

> DMS unit: Lump & Fines: Cyclones

> Lump size: +8 -32 mm/Fines +2 -8 mm

Parameter Jig DMS

Number: lump 2 1

Number: fines 2 2

Medium None FeSi


Capex and Opex

> Capex

> Opex

Direct Costs Equipment Installed

Bulk Earthworks & Civils

Platework, Structural & Piping

Electrical & Instrumentation

Buildings Design Contingency

Freight Total Costs

DMS $16,01M $3,13M $3,65M $2,55M $0.58M $2,59M $1.00M $29.51M

Jigs $16,71M $3,27M $3,81M $2,66M $0.61M $2,71M $1,04M $30.81M

Area Fixed Variable Misc. Total % Total

Labour Power Reagents &

Consumables

Maintenance $/tonne Costs

DMS plant $0.56 $0.73 $4.41 $0.34 $0.04 $6.08 35.5%

Jig plant

$0.56 $1.04 $0.75 $0.35 $0.00 $2.70 12.5%


THANK YOU www.metsengineering.com

john visser, mineral engineering technical services pty ltd: a comparison of jigging and dense media...

Business