The anodic oxidation process consists of creating a protective oxide layer on the surface of the aluminium, which gives the aluminium a high resistance to corrosion as well as an aesthetic effect.
The anodic oxidation of aluminium is divided into cold hard oxidation and classic oxidation, the difference between the two processes is the chemical resistance factor and the micron thickness of aluminium oxide that is formed.
The chemical phases to realize a correct anodic oxidation process on aluminium are :
Degreasing and preliminary cleaning of the piece, acid pickling to dissolve the external layer, chemical satin finishing to make the surface uniform and opaque, neutralization to set the pieces to the following processes and after the anodic oxidation process, chemical surface fixing.
Given the strong aggressiveness of the baths that constitute the anodic oxidation process of aluminium, the outgoing effluent produced by this processing presents a strong pollution, with a strong presence of aluminium in solution and sulfates that require specific water purification plants.
Pentacque offers its best purification plants of the chemical-physical type with dedicated sections for sulphates abatement, and integrated with automatic sludge dewatering, the plants are completed with resin backflushing demineralization systems for the high purification of final washings after fixing and resin plants for the purification of baths containing sulphuric acid for an optimal maintenance of aluminium concentrations in solution.
Thanks to these types of water treatment and purification plants we ensure the best result, guaranteeing the respect of the tabular limits and an economy of production due to the recycling of water and the high quality of the washings.
The water treatment plants normally proposed in the galvanic sector are:
- Continuous chemical-physical purification plants
- Sulphate abatement sections
- Sludge dewatering plants with filter press specific for anodic oxidation
- Ion exchange resin purification plants with total recycling backflushing ion exchange resins
- Plants for concentration or vacuum evaporation of eluates and concentrates
- Recovery and purification plants for acid baths with resins