John Reid

Topic: Removing calcium metaborate from bright nickel

We have a problem with calcium metaborate in bright nickel solution.  Does anyone know how to remove this?  According to our information it does not work in the same way as calcium sulfate (i.e. heat and filter).  Is there another way?


Re: Removing calcium metaborate from bright nickel

Have you tried to treat a small portion of the bath with potassium fluoride?  A great deal of the calcium will for calcium fluoride which will precipitate and can be filtered from the solution.  Caution:  Run a trial on a small sample (1 liter) before you add the material to your working solution


Re: Removing calcium metaborate from bright nickel

Calcium can be precipitated out of solution as CaF2. Use only as much fluoride as required as excess fluoride may attack titanium baskets and heating coils.  With bath in a clean treatment tank, heat and maintain above 170 deg F.  Use as much agitation as possible. Add either of the following per 100 ppm of Ca to be removed:
ammonium bifluoride = .06 grams/liter
sodium Bifluoride = .12 grams/liter
You may sprinkle a small amount of boric acid on the surface to promote nucleation.  Allow to mix for 60 minutes. Filter back to plating tank and adjust temperature.