Italian lead battery recycler STC is in the final commissioning stage of a five tonnes/h plant in Nigeria.
STC designed, built and supplied the complete lead-acid battery recycling plant for the Nigerian company Green Recycling Industries based in Agbara, Ogun State.
The final start-up of the whole plant is expected by the end of August.
The plant includes a breaking and separation area, lead paste desulfurisation, double effect evaporator to concentrate ammonium sulfate solution, and a final lead smelting and refining area inclusive of a lead ingot casting machine and an air pollution control system.
STC has used its patented U4Lead® process, which is based on a desulfurisation reaction carried out by means of a specific amino compound which leads to a residual sulfur content below 0,3%. The ammonium sulfate solution can be used as fertiliser in liquid form.
An STC spokesman told BEST: “The project is a unique design specifically made for GRI. The main innovations are the desulfurisation process U4lead and the paste pelletisation that are the only example, for what I know, in the world.”
The project also includes a tilting rotary furnace for smelting the clean coarse metallic fraction, with the molten lead transferred through a channel to the refining kettles for final lead ingot production.
STC has also completed the design and construction of a new rotary furnace for lead paste smelting operations. The furnace is supplied with an automatic feeding system and bullion and slag recovery unit with an automated trolley for crucibles.
The furnace design and construction was implemented using CAD/CAM systems, automatic submerged arc welding and a CNC vertical turning lathe.
An STC statement said: “The furnace will work with almost completely desulfurised material (negligible sulfur content – in lead paste <0.3% and in metal and grids < di 0.1%) with a consequent reduction of sulfur emissions such as SO2 – below 50mg/m3 – in the fumes released from the chimney.”