AMAX Base Metals Research & Development, Inc., Carteret, NJ
Pyrophoric Zinc Powder


AMAX wanted to dry a highly pyrophoric, water-wet, metallic zinc powder from 20% to less than 0.5%moisture as well as maintain 99.99% purity. Zinc, recovered electrolytically, requires drying before being cast into ingots for subsequent shipment or distribution. Conventional air drying techniques produce a white zinc oxide coating on the gray, sand-like particles, and in some instances, actual conflagration occurred when the dry state was approached. A closed-circuit TURBO-DRYER® using recirculated nitrogen was installed. The unit provides intimate drying gas contact with the zinc powder, facilitating close temperature control and high heat and mass transfer rates. In addition, the gentle materials handling and low exit gas velocities eliminate the need for dust collection equipment. The system produces 150 Ib/hr of 99.99% zinc with no white oxide impurities and without the danger of fire.


« Go Back