Can The Antimony Fining Of Speciality Glass Be Replaced?

Speciality glass is often fined with antimony. Because of environmental legislation the use of antimony and arsenic could be restricted. Therefore special glass manufacturers are looking for less toxic fining agents. Fining experiments including evolved gas analyses of batch, measurements of reboil temperature, oxygen fugacity and optical transmission were made with different fining agents to compare the fining efficiency of antimony, cerium oxide, and sodium sulphate. Preliminary results show that antimony can be replaced by a sulphur/carbon fining; but problems may arise due to higher reboil tendency.