Aluminium anodic oxidation

Anodic oxidation is an electro-chemical process commonly used with aluminium to form an oxidised surface layer for greater resistance to corrosion.

The layer may be anything from a few microns up to 20-25 microns thick.

The thicker the oxidised layer, the greater the resistance to atmospheric agents of treated parts.

The anodic oxidation process generally consists of several phases, including de-greasing, pickling, chemical satination, anodic oxidisation, organic and inorganic colouring, fixing.

In some cases the process also includes the chemical or electrochemical polishing of aluminium, using strong acids such as sulphuric + phosphoric + nitric or chromic acid in very high concentrations and at high temperatures.

These process phases generate waste water containing acidic and alkaline pollutants, heavy metals, colourants and various other components.

ITALPLANT has consolidated its presence in this sector with the construction of numerous plants, generally Chemical Physical ones, integrated with Ion Exchange Resin plants for the recycling of water used for final rinsing.

For anodic oxidation baths we build Retarded Ionic plants dedicated to the recovery of sulphuric acid, thus preventing the need for the periodic processing of baths, to maintain constant acid concentration levels and limit the increase of dissolved aluminium.

For the polishing process we build Closed-Circuit systems for rinsing water, with the installation of vacuum Evaporation machinery.

Such machinery is created using special technologies and steels resistant to conditions of extreme corrosion caused by acids contained in baths.

The Anodic Oxidation process also generates a considerable amount of sludge which must be thickened and compacted, for which we provide a vast range of Filter Presses, also for automatic continuous operation.

Numerous applications in the sector are our best reference.