During smelting, an additional is added which combines with impurites to form a fusible mass. The additional substance is called

During smelting, an additional substance is added which combines with impurities to form a fusible product. The substance added is known as :

During smelting, an additional substance is added which combines with impurities to form a fusible product. The substance added is known as :

During smelting, the additional substance added, which combines with impurities to form a fusible, mass, is called

During smelting an additional substance is added which combines with impurities to form a fusible product which is known as :

During smelting, an additional substance is added which combines with impurities to form a fusible produuct. It is known as :