Nonferrous waste as a source of zinc for electrogalvanizing

"One objective of Bureau of Mines recycling research is to devise technology that enables recovery of metals and minerals from wastes. From October 1982 through September 1985, researchers at the Bureau and at the University of Missouri--Rolla (contract h0222002) investigated the use of nonferrous flue dust with varying zn contents (11 to 66 pct) as a source of zn for electrogalvanizing steel wire. The waste dusts used were from a secondary cu smelter, a brass smelter, a pb smelter, and a water treatment plant. The dusts were leached in h2so4, and the leach solutions were treated to make electrolyte for electrogalvanizing steel wire using soluble zn anodes. Cyclic voltammetry was used in an innovative method to evaluate the quality of the electrolytes used for electrogalvanizing. After electrogalvanizing, the wire was drawn on a laboratory draw bench to simulate industrial practice. Corrosion resistance was measured by a number of electrochemical techniques and by the standard ASTM salt-spray tests. After successful bench- scale tests, the process was demonstrated in an industrial pilot plant. Results indicate that nonferrous flue dusts can be used as a source of zn for electrogalvanizing if certain impurities are either partially or completely removed from the starting electrolyte." - NIOSHTIC-2NIOSH no. 10005897198