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Gekko Systems
Operations & Maintenance Training
Future Trends in Processing
Gekko Systems Ballarat- March 2009
Outline
What do we see as the future of gravity?
The Future Gravity Circuit
Underground Processing
Air Pulsed Jigs
Gravity/Flotation/Intensive Leaching
High Rate Electrowinning Cells
Innovative Use of Existing Machines
What do you see as the future of gravity ?
Future Gravity Circuit Proposal
FREE GOLD – South Africa
Underground Processing (Python)
Magnetics Removal (MagScreen)
Higher Efficiency for Gravity
Increase Mill Throughput
Reduced Wear
Intensive Cyanidation for Float Concentrates
Air Pulsed Jigging
Provision For Controlled concentrate recovery
Coarse size recovery
Supporting Equipment
Thickeners
Regrind Mills
Underground Processing
Concept: To take Gekko processing technology as close to
working face as possible:
Reasoning: To reduce handling and pre-concentrate as early in
the extraction process as possible
Benefits:
Improvement in call factors (reduced losses between mine and mill)
Reduced surface capacity required (haulage, hoisting, processing,
tailings)
Underground Processing
Gravity/ Flotation/ Intensive Leaching
„GFL CIRCUIT‟
BGF, San Jose, Ho Gan
Gold / Sulphur Recovery with IPJ‟s
Primary, Secondary, Scavenge
Flotation Scavenge for Fines Recovery
Gangue Rejection in Grinding Circuit
Concentrate Leaching with ILR Circuit
Innovative uses of Existing Machines
IPJ
New Applications: i.e. Environmental/Waste Processing
such as copper from plastic – wire recycling, lead
remediation, coal processing
New Locations: i.e. Diamonds/Uranium underwater? Jigs
mounted aboard a seabed diamond crawler?
Underground?
What about floating pre-concentrators –
in rivers/barge mounted?
Air Pulsed Jigging
High Throughput.
Low Operating cost (due to no FeSi to create a dense media).
No Environmental impact (only water used in the system).
Faster Start up and shut down times than compared to DMS.
Low maintenance cost.
Ease of use.
An concentrate and middlings fraction can be extracted by a
single unit to ensure high grade as well as recovery.
Full Gravity separation done on product SG.
Higher cut-points can be achieved than compared to Dense Media.
Gekko 1m wide Air Pulse jig Model
How an air Pulsed jig works
A Roots type air blower is used to generate a low pressure
compressed air (around 65kpa) for pulsation.
This air is blowed into the jig pulse compartment and then
released back into atmosphere by a set of pulse valves.
Pulse Explained
INLET TIME. This is when air from the blower enters the pulse
compartment and it generates a upward motion of water threw the
screen deck. “Differential Acceleration” takes place where the lighter
gang particles gets accelerated past the heavier particles and is placed
higher on the screen bed than the heavier mineral.
HOLD TIME. At this stage, the pulse is stopped and separation takes
place while all the particles settles down to the screen deck. “Hindered
Settling” takes place where the heavier particles settles down to the
screen bed faster than the lighter gang material.
EXHAUST TIME. The exhaust time is there to remove all the air from
the pulse compartment for the next pulse. “Consolidated Trickling”
happens when the heavy fine particles is sucked down to the screen
deck passing the light large particles.
Pulse pattern
BE
GIN
DE
LA
Y T
IME
INL
ET
VA
LV
E O
PE
NIN
G T
IME
INL
ET
VA
LV
E O
PE
N T
IME
INL
ET
VA
LV
E C
LO
SIN
G T
IME
SE
TT
LIN
G H
OL
D T
IME
OU
TL
ET
VA
LV
E O
PE
NIN
G T
IME
OU
TL
ET
VA
LV
E O
PE
N T
IME
OU
TL
ET
VA
LV
E C
LO
SIN
G T
IME
EN
D D
EL
AY
TIM
E
PULSE LENGTH
Air / Water
Particle Bed
Hindered
SettlingConsolidated
TricklingFluidization
Rest
Timer Value 1 Timer Value 2 Timer Value 3 Timer Value 4
Typical Jig Feed
The Air Pulsed jig is fed by a wet screened feed material.
The feed is broken down into a few different size fractions. For
example typical sizes will be: -3mm, +1mm; -8mm, +3mm;
-25mm, +8mm.
Larger sizes of up to 50mm can also be treated in air pulse jigs.
There needs to be a significant SG difference between the
concentrate and gangue material for the jig to work at its best, and
a lot of close density material can contaminate the concentrate
grade.
Air Pulsed Jigs are mainly used in Metals from slag, Iron ore,
Manganese, Coal and Diamond industries, but can be used to
separate any material with a significant SG difference.
Water in the circuit
Process water that is used as a medium in the jig, does not need
to be clear.
Slimes is removed from the system by using a cluster cyclone and
or thickener arrangement. On a full operating plant, there will need
to be a slimes dam to ensure fresh water for the plant as
additional makeup water.
The only water losses will be the wet tailings, concentrate as well
as the water lost in the slimes dam circuit.
Bed Level Control.
The concentrate in the jig bed is determined by a float that is set
up to be “riding” just above the level of heavy concentrate.
The float level is measured by a ultrasonic level sensor and its
position is send to the PLC for processing.
The desired Bed level is set in the PLC by the operator.
The PLC will increase or decrease the speed at which the
concentrate is discharged by the concentrate feeder to obtain the
desired bed level.
This system ensures that a high variety in feed grade and feed
rate can be processed without any impact on grade or recovery.
Bed Level Control Schematic.
PLC
Jig Pulse Management System
a Jig pulse management systems will be included to give the
advantages as listed below.
Constant pulse wave motion.
Constant pulse height.
Constant pulse velocity.
Handles the feed grade and feed rate differences and adjust the jig
pulse to accommodate these inconsistencies.
Innovative Uses of Existing Machines
• ILR
Larger units – pre-concentration for low grade
continuous units particularly Flotation Concentrates
Un-clarified electro-winning
Alternative lixiviants
Other metal concentrates – copper, zinc,
manganese etc??
Micro ILR & Electro-winning: Briefcase sized unit
The Gekko Electro-Cell was
developed as a high efficiency
cell for the production of high
volume silver sludge and gold.
The cell was developed for
Hochschild‟s silver applications
with experience gained from site
and the laboratory.
The installed cost of the cells
was kept to a minimum on a per
kg production basis.
The Gekko Electro-Cell
The Electro-Cell
Silver
Launders
Sludge eduction
system
Cathodes and
Anodes
Design Criteria Easy high sludge mass recovery from bottom of cell (total 600 L sludge capacity/cell)
High electrical efficiency
High current density
Simple to use
Low cost simple design
Technical Information
PLS Flow m3/h 0-30 m3/h
External Cell Dimensions 2966mmL*1356mmW* 2260mm High
Cathode Dimensions 1000 mm * 1000 mm
Voltage 0-10 VDC
Maximum Current 3500 Amps
#Cathodes 19
#Anodes 20
Current Density 0-20 A/m2
Volume of cell (Total including sludge collectors) 3300 L (To bottom of overflow)
Volume of cell (box) 2700 L (To bottom of overflow)
Silver plating rate – 20% Efficiency 2,820 g/h
Silver plating rate – 40% Efficiency 5,640 g/h
The Box
Simple folded design with
high rigidity allows lighter
construction
Integrated cover incorporated
in main structure
Low working height with base
of cell protruding through
floor
Cathodes
Simple bolted design
High conductivity
Secure ss wire stocking
connection
All gang connected to main
bus rail for ease of removal
Custom lifting jig for safe
simple removal
Anodes
Simple bolted design
High conductivity
Secure woven wire
connection for higher surface
area
All gang connected to main
bus rail for ease of removal
Custom lifting jig for safe
simple removal
Bus Bars
Distributed input power along
copper bus for minimising
voltage drop and heat
generation
Solid construction for
continuous connection along
full length of cell
Simple taper wedge locking
system for fast removal and
critical power connection
High air flow directed over
bus to ensure cooling
High Mass Recovery Launders
Three pyramids per base for
sludge recovery, each
capable of containing 200
Litres of sludge
Baffle plates in each pyramid
to minimise short circuiting
Remote controlled valves on
discharge system for
continuous sludge recovery
Eductor system for sucking
sludge from base of launders
Sludge removal whilst cell is
in operation
Ventilation
Smart cover for fast removal
Air drawn across top of
cathodes and anodes to
ensure fumes extracted to
outside of the building
Ventilation flow drawn from
under the bus bars to cool
bus first.
Fast Cathode Cleaning
Flow bypassed
Rectifier off
Anodes removed
Cell drained
Eductors on
High pressure wash of
cathodes in-situ
Anodes replaced
Cell filled
Rectifier on
Flow on
Summary
The only cell specifically designed for silver recovery
High current density for silver sludge generation
High current efficiency
Custom designed base launder for ease of sludge recovery
Quick connect distributed bus system
All stainless steel construction reduces risk of fire
Individual anode and cathode packs for ease of removal
Low cost design
What do we see as the future of gravity?
Novel and Innovative uses for existing machines
New ancillary products for existing machines
New Ancillary Products for Existing Machines
MagScreen and ISP Combination
successfully trialled,
MagScreens installed and
operating at Kencana
New Ancillary Products for Existing Machines
AuRIX resin and contacting
column to extract gold and other
metals from solution at different
solution pH
Regrind Traction Mills Compliment Leaching circuit when grind sensitive
Two sized machines available
Compact, simple design, skid mounted units
Thickeners Compliment Leaching circuit for High Eefficiency Closed
Circuits
Low cost solid liquid separation devices
Three sized machines available
2m Diameter (Up to 2 tph)
3m Diameter (Up to 5 tph)
4m Diameter (Up to 10 tph)
Simple, Transportable Design
Low installation & commissioning time
High Density Discharges
Load Cell Control
What do we see as the future of gravity?
Novel and Innovative uses for existing machines
New ancillary products for existing machines
Gravity as an alternative to CIP
Can Gravity Replace CIP??
Gold Recovery Yield Curve
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0% 20% 40% 60% 80% 100%
Yield
Re
co
ve
ry
Gravity as an alternative to CIP
Advantages:
Low capital and operating cost
Easier to operate
Environmental aspects of cyanide disposal are reduced
Reduced power consumption through increased grind size
Sterilises preg-robbing components
Alternative Flowsheet
Crushing
Classification
Milling
Gravity
concentration
Intensive
Cyanidation
Non-cyanide
Tailings Disposal
Cyanide Tailings
Disposal
Gold
Smelt
Gravity
concentration
Further Alternative Flowsheet … GFL
Crushing
Classification
Milling
Flotation
Intensive
Cyanidation
Non-cyanide
Tailings Disposal
Cyanide Tailings
Disposal
Gold
Smelt
Gravity
concentration
What do we see as the future of gravity?
Modular plant
Novel and Innovative uses for existing machines
New ancillary products for existing machines
Gravity as an alternative to CIP
Modular Plant
Advantages:
Mobile
Low capital and operating cost
Easy to assemble
Fast delivery
Containerised, minimal site work
required
Expandable up to 150t/hr per module
Modular Plant
Typical Modules:
Feeder/Scrubber
Crusher
Mill
Screen
Pre-concentration & Separation
Concentrate treatment
Detox & scavenging
Refining
Laboratory
Meccano for Miners
Now what do you see as the future of gravity…
Lets Explore …
Gravity is relatively inexpensive and
environmentally friendly, it‟s further use and
development is virtually guaranteed!
Gekko will continue exploring novel and
innovative ways of using gravity in conjunction
with you, our customers.
If you have ideas or suggestions, let‟s explore
them together……….
