Tata Steel in Shotton produces pre-finished steel, primarily for the domestic appliance and construction industry, and generates some 45,000m3 per annum of metals laden effluent, primarily dissolved Zinc.
However with the effluent plant built in 1976 and having been designed to cater for a time when the site was an integrated steel plant, the Tata team recognised that change was necessary. They needed equipment to pilot a new treatment process with the aim of ultimately phasing out the old treatment plant.
The Overall Objective
The aim of the pilot plant was to test a new treatment process, which would reduce treatment costs and meet the site’s longer term needs. The site’s own projects team worked with their colleagues from Tata’s Swinden Technology Centre to establish a chosen method of treating the metals laden effluent.
They then engaged SPS to discuss and review this information, and to design install and commission a pilot system that could treat 20m³/hr of effluent.
The treatment system consisted of mixed reaction tanks, a lamella clarifier, pumps and dosing systems and associated control. The new treatment has proven to be much more efficient than the one it replaced. It occupies a very small footprint by comparison, uses far less process chemicals and generates a fraction of the original plant’s filter cake volume.