Project targets energy lost during aluminium recycling

London - HRS Heat Exchangers is to participate in ALUSALT – a consortium seeking to develop an advanced flue gas transfer system for an in situ salt cake recycling technology in aluminium recycling facilities. HRS is to focus on the flue gas transfer system hardware.

Processing of recycled aluminum generates by-products like salt cake and dross. The salt cake stream consists of aluminum, salt and oxide residue (non-metallic product).

ALUSALT aims to develop a flue gas transfer system that will take the heat and pressure of the flue gas from the rotary furnace. The heat would be reused to evaporate the water via a single-stage forced circulation evaporator.

The new process will reuse all available energy that is lost during the aluminium recycling process and will require no additional energy for the salt cake recycling, said HRS. The new concept is to inject the hot flue gas from the rotary furnace through specialised nozzles.

The temperature and pressure of the flue gas injection through the nozzles will be controlled by adding super-heated steam along with the flue gas. The flue gas will create convection current in the brine, which will increase the evaporation rate.

The heat and pressure of the flue gas will eliminate the need to use a multi-stage evaporator, which will reduce the size and the initial capital expenditure costs compared to the current state-of-the-art salt cake recycling system.

“Our expertise will facilitate us to help develop an advanced flue gas transfer system which will enable ALUSALT to create a recycling system that will be 10-15 times smaller than existing technologies,” said Arnold Kleijn, business development manager, environmental industry at HRS Heat Exchangers Ltd.

“This will make salt cake recycling more accessible, cost effective and safer on the environment,” added Kleijn