Cement Industry
Process Water Treatment Plant – 2.6MLD
Problem Statement
This leading cement manufacturer in South Africa is making use of 2 water sources in its processes, Borehole and River. The challenge faced is high hardness levels in the source waters which causes scaling in heat exchange units such as condensers, coolers, cooling towers and boilers. Scaling reduces the work rate of equipment and systems. Hardness differs in all sources: River up to 350mg/l, Borehole up to 1000mg/l.
Solution
The solution was to build a water treatment plant that would reduce the hardness in the water via a chemical softening process providing soft water for the processes which in turn would increase the working capacity of all heat exchange units. This also increased the output of the waste heat recovery system increasing power output.
Typical Plant Feed
- Hardness level between 250 to 1000mg/l
Performance Target
- Up to 110 m3/hr plant production
- Hardness <50mg/l
- Conductivity <250microsiemens/cm
- RO recovery rate of 70-75%
Process
- Chemical addition
- Reaction tanks
- Settling
- Sand filtration
- Reverse Osmosis
- Sludge handling
Sustainability
The Cement production site has its own Waste Heat Recovery unit that generates power for the plant. Since the running of the new water treatment plant, the customer’s power generation has increased from 3MW to 5.5MW and 6MW.
