Filter for electroplating plants

Abwasser aus Feuerverzinkerei/Waste water from galvanizing plantAbwasser aus Feuerverzinkerei/Waste water from galvanizing plant
With modern filter technology, electroplating plants can bring their waste water values below the required standards. Therefore the choice of a good water treatment plant is crucial for the recovery of process water. The automatic self-cleaning system offered by GEFA Processtechnik represents an ecologically and economically favourable solution. It cleans the water contaminated with chrome, nickel, copper, lead and other washing residues as well as oils so effectively that it can be returned to the process.
In the hot-dip galvanizing process, steel coils are unwound in a continuous process and, among other things, dressed / straightened and re-rolled. This is intended to prevent the running mill effect and give the steel sheet the desired surface fineness. During this process fully demineralized water is used at two points:
Before skin pass dressing, water is sprayed onto the sheet surface to create a thin sliding film.
Before the re-rolling process, high-pressure nozzles spray over the full width of the steel sheet to remove deposits and impurities. These would otherwise leave a "permanent impression" and reduce the quality of the coil to the point of unusability.
This waste water poses problems for hot-dip galvanizing plants with conventional cleaning:
  • Bag filters are not effective enough and do not achieve the desired discharge values, especially with high dirt loads.
  • In high-pressure applications, more fresh water is turned into wastewater than necessary or even allowed.
  • Losses from carry-over, evaporation and rinsing water through the plate material must be replenished with deionized water.

Most of the bag filters used are made of needle felt with a filter fineness of 10μm. However, these quickly become blocked in the event of high dirt loads or oil in the water. The machine operator has to change them and stop the process. In addition, bag filters cause a lot of effort due to handling, recurring purchases, storage or disposal.

The solution to these problems is a new filter concept consisting of the following components:
  • An oil separator removes the entrained leakage oil from the wastewater. The oil-water mixture is then pumped to a special plate separator, which has an effectiveness of 95%. The water flows back into the waste water tank and has an oil load of only 10mg/l.
  • The dirty water from the tank is pumped to an automatically self-cleaning filter GEFA Filtomat with 50μm filter fineness. This is a pre-filter for the deep bed filter.
  • To reduce the concentration of oil in the water to a maximum of 5mg/l, an activated carbon filter is used. This has an assumed regeneration interval of 3 months.
  • In the last step, all colloids remaining in the water so far are removed from the water with a MT-IBA microfiber filter with a filter fineness of 3μm.


  • Removal of rust and iron particles
  • Filtration of black particles
  • Re-use of rinse water
  • Recovery of process water
  • Reduction of waste water quantities


You can find more product information here!

FW-Rückspülfilter MT-IBA4-Microfiltration
Type FW Type MT-IBA-Microfiltration


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