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Chromic acid recovery by cation exchanger ReKat

Description of system

With the standard systems ReKat I and ReKat II, two inexpensive cation exchangers of different sizes are available for the removal of foreign metal ions from chromatic solutions.

The higher the extent of recovery of entrained chromic acid – whether it is through a simple recirculation of energy-saving rinses or a 100% recovery with our well-known recovery processes through the evaporation of rinse water and scrubbing of exhaust air – the faster the content of dissolved foreign metals and trivalent chromium will increase, so that purification is required.

Chromic acid solutions with concentrations of up to 80 – 100 g/l CrO3 can be freed from disturbing metal ions with the strongly acidic cation exchanger. The etching baths that are being enriched with iron are also included in the purification cycle.

Several liters per hour are continuously withdrawn from the chrome and etching baths, diluted with rinsing water and then purified via the strongly acidic cation exchanger. The purified chromic acid solution is then available for filling up losses due to evaporation. In case of high entrainments involving multiple replacements of the chrome bath per year it is also sufficient to only purify the rinsing water. It is important for the cation exchanger to remove the amount of foreign metals that reaches the chroming process, so that the electrolyte is kept below the tolerable concentration of contaminations. The strongly acidic macroporous cation exchanger resin has a high porosity with a high capacity and high reaction speed. It is characterized by its excellent mechanical stability and oxidation resistance. Cation exchanger resin permits chrome concentrations of 80 to 100 g/l (as CrO3) with nearly no attack on the resin matrix and a sufficiently reduced counterion effect, so that a usable volume capacity of ca. 1 val/l is achieved.


  • No draining, decontamination and new preparation of chromic acid solutions contaminated with metals
  • Recovery of chromic acid by foreign metal removal with strongly acidic cation exchanger
  • Reduction of excessive Cr³+ concentration
  • Concentration of purified chromic acid solution is possible with our chrome recovery (without supply of external energy) or evaporator
  • Can be easily installed onto existing systems, little required space
  • Also suited for the regeneration of chromatizations
  • Equipped with very modern control technology with valve manifold and PLC control and control display
  • Fully automatic complete plant with regeneration container, resin filling, mounted on a stainless steel frame

More information:

Phone +49 711 518550-130 or -141