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Save Money and Reduce Waste: Pollution Prevention for Metal Finishing

High disposal fees and raw material costs can be a financial drain on your metal finishing operation. To remain competitive and go beyond compliance, pollution prevention (P2) can be the easiest and best management choice for reducing these costs and waste issues.

Instead of concentrating on treatment, P2 focuses on optimizing processes, reducing raw materials and preventing losses. As a metal finisher, you can use the following principles when developing a P2 strategy:

  • Use the least toxic and easiest to manage chemicals.
  • Extract the most life (use) out of process chemistries.
  • Keep process chemistry solutions where they belong (in the process tanks).
  • Return as much escaping solution (dragout) as possible to your tanks.
  • Use the least amount of rinse water required for good rinsing.

Understanding P2 principles related to metal finishing helps identify areas where waste minimization opportunities exist within your operations. P2 techniques for metal finishing include the following:

  • Slow down — Reduce the speed of parts removal and allow drain time above process tanks to reduce dragout.
  • Counter-current rinsing — Feed fresh water into the rinse tank farthest from the plating tank and have it overflow backward through the flowing rinse tanks until it reaches the rinse tank immediately after the plating tank.
  • Static rinse — Make the first rinse after a process bath a static rinse that builds up a concentration of dragin and is used instead of fresh water to replenish the process bath.
  • Rack to reduce dragout — Position the part so that fluid will flow together and off the part by the quickest route.
  • Bath chemistry — Regularly monitor bath chemistry with pH and conductivity controls.
  • Restrict water flow — Use simple in-line flow restrictors to limit the water flow rate.
  • Drain boards — Place a drain board over the lips of two adjacent tanks to catch dragout.
  • Fogging/Spray/Air Knives — After a part is removed from a bath, use these devices, located above process tanks, to force excess solution off the work piece and into the process bath.

For more information and assistance about P2 and waste reductions in a metal finishing process, contact Ohio EPA’s Office of Compliance Assistance and Pollution Prevention (OCAPP). OCAPP is a free and confidential program that helps identify and implement P2 measures that can avoid regulation, save money, increase your performance and benefit the environment. For more information about OCAPP and its services, please visit epa.ohio.gov/ocapp or call us at (800) 329-7518.