Zinc coating using galvanising baths
Your fabricated metal product business may use galvanising baths to coat your metal products with a layer of zinc.
Zinc reacts with the metal, usually steel, in the galvanising bath to form a series of iron-zinc alloy layers. This produces a thick coating that makes your metal resistant to corrosion, impact and abrasion.
What you must do
Comply with conditions in your permit
If you have a permit, licence or registered exemption you must comply with its conditions. Your permit may contain conditions which control the quantity and concentration of your air emissions.
You may need to reduce your emissions to meet the limits in your permit. You can be fined or even sent to prison if you do not comply with conditions.
Comply with your waste responsibilities
Your galvanising operations could produce a number of different waste materials, including:
- 'galvanisers' ash
- dross from the base of the galvanising bath
- dust from the bag filtration plant.
You must comply with your duty of care responsibilities when you deal with your waste.
Check if you need any discharge consents
Do not discharge anything to public sewers, surface waters or ground waters without consulting your regulator. You may need a discharge consent or other authorisation. For further information, see our guidance on discharges to water and sewer.
Good practice
Prevent dust and fumes
- Minimise handling of dusty materials and cover your containers.
- Dip materials in protective enclosures and turn on your extraction fans.
- Service your abatement equipment regularly and clean your chimneys to prevent deposits building up.
- Introduce reworked ashes to the bath in a way that will minimise your fumes, for example underneath the molten zinc surface via a screw feed.
- Keep galvanisers' ashes and drosses dry at all times to avoid the production of arsine gas.
Minimise your waste
- Set up work procedures to recover as much zinc as possible from reworking of galvanisers' ash.
- Reprocess your drosses and zinc ashes that are not suitable for reintroduction to the galvanising bath. You could reprocess them back into refined metal or other products such as fertilisers and tyres.
- Monitor the ash and dross you produce to evaluate the level of contamination that reaches your zinc bath.
Be a good neighbour
- Speak to your neighbours regularly about any issues with dust or fumes at your site.
- If you receive any complaints about air emissions deal with them quickly.
- Record the results of investigations into complaints and anything you do to correct the problem.