Electroplating – ABS chromating for automotive parts

Description:

New project in Italy for the treatment in closed circuit of rinse water after trivalent chrome plating process.
The introduction of the trivalent chrome  is a new challenge for the plastic chromating producers.
The elimination of the hexavalent chromium brought as consequence the presence of different pollutants contained in the rinses after the chromating process. One of the most problematic is the presence of Boron.

In recent years, SAITA has developed water solutions for various industries where the problem of boron treatment has arisen.

In this new project for a market leader in the production of automotive chromated parts an expansion of the existing water treatment plant has been realized. In order to integrate the boron treatment in the existing plant the solution was to install new closed circuit treatment plants for the rinses after the trivalent chromating process. An heat pump vacuum evaporator mod. EV400HT has been installed for the first static rinses, while for the dynamic rinses a recycling demineralizator with special Boron selective resins has been foreseen in order to confine the effluents containing boron in this new closed circuit system. The only waste output produced, containing Boron, is the liquid concentrate produced by the vacuum evaporator  (<10%).

Liquid waste that is then further treated in a batch chemical-physical plant for the precipitation of Boron as dried sludge with a special chemical process developed by SAITA. So for this particular application a Zero Liquid Discharge solution was successfully applied.

Technical characteristics:
Evaporator’s capacity 9000 Lt/day
Electrical consumption 180 Wh
Distilled water recovered >95%
Conductivity < 10 us/cm
Automatic functioning H24
Disposal of dry sludge

Highlights:
Boron chemical precipitation
Zero Liquid Discharge
Distilled water recycle
Boron selective resins