This invention involves the novel use of a traditional screw pump as a circulating pump for GaInGn liquid metal. The screw pump moves liquid metal while minimizing the entrainment of oxygen. No contact is made between the pump housing and impeller, thus the production of hot spots is avoided. Hot spots and strong mixing aid oxidation. Conventional gear and centrifugal pumps entrain oxygen and ruin the eutectic. Electromechanical pumps are expensive and have a contact corrosion problem.