By: Tomasz Bławut, Messer Polska, and Antonin Kroupa, Messer Group

CO₂ neutralizes zinc wastewater

Poland | ZGH Bolesław is a mining and metallurgy company that produces high grade electrolytic zinc and zinc alloys. To neutralize the wastewater from its zinc extraction operations, the company uses liquid carbon dioxide from Messer. The wastewater has a very high pH ranging from ten to eleven, which must be lowered to the neutral range before discharge.


ZGH Bolesław’s modern mining and smelting complex in Poland

In the past, this was done by adding sulfuric acid – with undesirable side effects: handling that acid requires extensive safety precautions; it is difficult to control the dosage; and the wastewater neutralized with it is salt-laden and corrosive. Messer conducted a successful series of CO₂ neutralization tests at ZGH Bolesław and subsequently received the order to install the equipment for this process. Today, a tube reactor neutralizes 20 to 30 cubic meters per hour of wastewater in an eco-friendly, cost-effective process.