Crystallizer ReKrist

Description of plant

Alkaline plating solutions, with and without cyanide, have the tendency to form and accumulate sodium carbonate. Exceeding a concentration of 50-60 g/l Na₂CO₃ will cause plating problems with regard to efficiency and quality. Modern zinc-iron- or zinc-nickel-alloy plating solutions require a tight control of the sodium carbonate level. The new compact ReKrist crystallizer has shown excellent results for the control of this plating solutions. The system includes a double jacketed stainless steel tank with heat insulation and a cooling machine with a cold water recirculation. An air-operated diaphragm pump controls the supply of the plating solution, the recirculation during the crystallization process, the return of the purified electrolyte, and the discharge of the sodium carbonate. The crystallizer vessel has a slow rotating scraper to avoid carbonate buildup on the walls. The system is controlled by PLC to adjust the system to the working requirements. Besides sodium carbonate the system removes other contaminants of this plating solutions like sulfates and oxalates.

• Ready to connect unit, mounted on stainless steel frame, mobile chiller
• Integrated rotating scraper system
• Siemens PLC S-7 and display OP-17, includes automatic shut-off-program
• Standard crystallizer material stainless steel 1.4301, other stainless steels on request

Other Applications and systems: Regeneration of sulfuric acid/hydrogen peroxide containing etching- and pickling solutions for copper and copper alloys, for printed circuit boards, for metal production like plate metal, tubes etc. Crystallization of copper sulfate CuSO₄x 5 H₂O. Regeneration of sulfuric acid pickling solutions for steel by crystallization of iron sulfate FeSO₄x 7 H₂O.

Applications