Using chemicals as stripping agents
A proportion of your components will not have the desired surface finish and you will need to strip them before they are reprocessed. You might also periodically strip your jigs. Stripping is usually achieved using alkaline agents, eg hydrogen peroxide, followed by acid stripping agents, eg nitric acid.
What you must do
You need to carefully manage chemicals used for stripping as they are corrosive and contain significant quantities of metals. Rinse waters used in the rework area will contain ever-increasing quantities of metals when they are reused.
Ensure that you do not make any discharge to public sewers, surface waters or groundwater without consulting the appropriate regulator.To make a discharge without the appropriate permission may be an offence and could lead to enforcement action.
You must comply with your duty of care responsibilities when dealing with waste.
Due to their hazardous properties, you must handle spent stripping agents and sludges from stripping tanks as hazardous/special waste.
- If you use dip-stripping tanks, carefully monitor the temperature of the tanks to prevent excessive evaporation. Cover the tanks when they are not in use.
- When stripping solutions eventually need to be discarded, they will contain a significant amount of metal residue. Where possible you should recover this metal as it could benefit you financially, particularly in the case of precious metals.
- Use the minimum possible amount of stripping chemical.
- Carefully store stripping chemicals in a bunded area. This will prevent chemicals entering drains or watercourses.