Replacement of carbon steel pipes by Pexgol pipes for tailing lines.
Ambatovy for it nickel mine has 15 km of tailing lines. The tailing distribution lines are made of DN700 carbon steel and this pipelines suffered from repetitive and frequent failures.
This failures were because of the effect of erosion, mainly due to the high liquid velocities inside the pipeline, especially in those areas where there is slack flow in the line.
To a lesser extent, further thinning of the pipeline wall occurs, due the presence of the highly corrosive ammonium sulphate salt (NH4)2SO4 . The frequent failures prompted the decision to replace the the carbon steel tailing pipeline with Pexgol pipes.
After designing the lines in cooperation with Paterson & Cook, Ambatovy decided to install Pexgol 630 mm pipes on 2017.
The pipes were installed down hill from the pumping station where velocities are high. Testing the wall thickness periodically showed minimum effect of wear on the installed Pexgol pipes.
Another advantage that Ambatovy pointed out as a reason to use Pexgol systems is the simplicity of dismantling and reinstalling Pexgol pipes when raising the dam’s level, which saves time and money if comparing this to doing it with carbon steel pipes or carboon steel lined pipes.
Madagascar | 2017
Slurry concentration of 35% solids
Temperature 70°C to 80°C
Composition (NH4) 2SO4
Flow 3,200 m³/h (2.3 m/s)
Pexgol 630 mm, Class 15