1. Corporate Office: 4461 Cox Road Glen Allen, VA 23060 Bruce Bowen ChemTreat, Inc. Sales Manager Plainwell, MI

2. Chemical Precipitation of Metal Hydroxides

3. INDUSTRIES IMPACTED: Metal Finishing Foundry and Casting Mining Microchip/semiconductor Production Automotive Printing

4. HEAVY METALS IN QUESTION: -Zinc-Nickel -Chromium-Copper -Tin-Mercury -Iron -Cobalt -Silver-Aluminum -Cadmium -Arsenic

5. Precipitation of Heavy Metals as Hydroxides

6. Precipitating Agents Calcium Hydroxide - Ca(OH) 2 Magnesium Hydroxide - Mg(OH) 2 Sodium Hydroxide - Na(OH) Soda Ash – Na 2 CO 3

7. Zn 2+ (aq) + CO 3 2- (aq) = Zn(CO 3 ) (ppt) Zn 2+ (aq) + 2OH - (aq) = Zn(OH) 2 (ppt) Precipitation Reaction

8. Typical Concentrations Obtainable Through Conventional Chemical Precipitation Achievable Concentration Precipitating Heavy Metal (mg/liter) Agent Cadmium 0.3Soda Ash Trivalent Chromium 0.5Caustic, Lime Copper 0.5Caustic, Lime Iron 1.0Caustic, Lime Nickel 0.5Soda Ash Zinc 0.5Caustic, Lime

9. Typical Treatment Plant

10. Post Treatment Polishing Anti-Chelation Chemicals: Dithiocarbamate Sulfide (Na 2 S)

11. Post Treatment Polishing