Transcript Slide 1

HybridICE Freeze Crystallization
Cost of desalination technologies
Technology
Running
cost
3
3
R/m
CSIR ABC (Alkali-Barium-Calcium) Process
KeyPlan HiPRO Process
AR Technologies Sodium Carbonate Reverse Osmosis
Process (ARRO)
Mintek SAVMIN
EARH Ion Exchange
Paques Thiopaq Process/CSIRosure
Biosure
TUT/CSIR MBA (Magnesium-Barium-Alkali) Process
(laboratory stage)
Lime treatment for Industrial water
Differen
Income ce
3
R/m
R/m
4.04
9.12
3.56
3.35
-0.49
-5.78
12.79
11.3
12.95
8.73
8.73
4.29
3.84
10.7
5.7
6.12
-8.51
-7.46
-2.25
-3.03
-2.61
2.22
5.5
5.58
0.7
3.36
-4.8
Gypsum from fertilizer industry
Sulphur import
Price
Cost of sulphur for SA
SA Total imports
Precentage
1 000 000 t/a
2 000 R/t
2 000 000 000 R/a
70 800 000 000
2.8
Sulphur Recovery flow diagram
CaSO4/Mg(OH)2/Coal
D
Sulphur
Pipco
1100 deg C
A
H2O
H2S
CaS(s)
MgO(s)
Mg(HCO3)2
H2O
B
CO2 from kiln
CaCO3/Ash
C
MgCO3
PUMPING OR NOT
Pumping cost
Parameter
Flow (Ml/d)
Current water depth (m)
Head, h (m)
Electricity cost:
Pump efficiency (%)
Power cost (R/kWh)
Electricity cost (R/m3)
Electricity cost (R/a)
Capital cost:
Pump cost (R/kW)
Pump capital cost (R)
Equalization pond cost:
Western
20
150
0.5
0.50
0.41
2 983 875
Basin
Eastern
Central
108
60
700
500
400
200
0.5
0.50
Total
188
0.5
0.50
1.09
0.55
42 967 800 11 935 500
57 887 175
16 000
16 000
16 000
10 900 000 156 960 000 43 600 000 211 460 000
40 095 873 154 892 364 95 494 429 290 482 666
Ph = q ρ g h / (3.6 x 106) where
Ph = power (kW); q = flow capacity (m3/h); ρ = density of fluid (kg/m3); g = gravity (9.81 m/s2); h =
differential head (m)
Recommendation: Determine whether ECL levels can be moved to higher
levels
When to pump
• Allow future mining and the protection of tourist sites.
• Protect ground water to be contaminated with mine water.
• Provide flow-equalization storage areas in sub-surface voids.
(Alternatively, such storage facilities (e.g. ponds) need to be constructed
on surface.)
Benefits associated when water is allowed to decant
• Less pyrites oxidation as a result of ingress water running through broken
rock; and
• Less pyrites oxidation due to no reciprocating contact of pyrites-rich ore
with water and oxygen as the water level fluctuates from water being
pumped out at a constant rate while the incoming water flow-rate
fluctuates with seasonal rainfall,
• Limited dissolution of limestone/dolomite due to ingress of rain water
Problems/Solutions to rising levels of acid mine water
Problem
Solution
Ground water pollution
Rand water distribution system
Damage to foundations
Injection of clean water
Acknowledgements
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TUT
Rand Water
THRIP
Industrial partners (KSH, Marlow Aquatec)