CORROSION OF CONCRETE
Obtaining of electrolytic copper requires the use of sulfuric acid during the treatment and electrowinning. In keeping with the above, a wet area is defined as the set and sequence of processes necessary to obtain electrolytic copper.
Broadly speaking, the wet area consists of a Solvent Extraction Plant (SX Plant); an Electrowinning Plant (EW); and a Tank Farm.
The metallic structures, floors and concrete walls are exposed to acid spills and highly aggressive environment.
The SX Plant of an important mining company had the concrete floors completely destroyed due to severe corrosion.
Strong corrosion in concrete due to contamination and acid spills.
After performing the diagnostic inspection, as well as the detailed study of the situation, the repair engineering was defined without stopping the process. The engineering consisted of: identifying and controlling leaks and interferences; structural recovery of floors and walls; redesigning floor slopes; designing the piping system; studying and designing a liquid residue evacuation and reception system; antacid coating design and application methodology. The work was done by a contractor with excellent results. The repair procedure considered cleaning with pressurized water, dragging and removing the sludge, breaking and rough grinding the damaged concrete until reaching the uncontaminated concrete, recovery of the grinded concrete with highly strength reinforced concrete. Once the new concrete was set, the surface was treated with pressure washer together with mechanical washing to remove slurries, salts and any surface impurity. Finally, the concrete was treated by abrasive blasting to get a finish with roughness equivalent to 60 grit sanding disc. When the surface was treated, the antacid protection system designed for the working condition and the projected repair system was applied. Special emphasis was put on the treatment of details such as junctions, returns, expansion joints, cracks and any other specific situation identified in the repair engineering. The antacid products include low viscosity primers, mortars, grouts, putties, paints and glass fabric reinforcement.