Bruce Bowen

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Corporate Office 4461 Cox Road Glen Allen, VA
23060

• Bruce Bowen
• ChemTreat, Inc.
• Sales Manager
• Plainwell, MI

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• Chemical Precipitation
• of Metal Hydroxides

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• INDUSTRIES IMPACTED
• Metal Finishing
• Foundry and Casting
• Mining
• Microchip/semiconductor Production
• Automotive
• Printing

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

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Precipitation of Heavy Metals as Hydroxides
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Precipitating Agents

• Calcium Hydroxide - Ca(OH)2
• Magnesium Hydroxide - Mg(OH)2
• Sodium Hydroxide - Na(OH)
• Soda Ash Na2CO3

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Precipitation Reaction

• Zn2 (aq) CO32- (aq) Zn(CO3) (ppt)
• Zn2 (aq) 2OH- (aq) Zn(OH)2 (ppt)

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

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Typical Treatment Plant
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Post Treatment Polishing

• Anti-Chelation Chemicals
• Dithiocarbamate
• Sulfide (Na2S)

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Post Treatment Polishing