43050

Nickel electrolyte aluminum contamination [India] 

November 16, 2006

sir,
my electrolyte solution is probably get contaminated by aluminum parts. I have dummy it for long time but still it is turbid even after filtering. so is there any tool to decontaminate the solution by chemical treatment other then dummy. my aluminum may have converted to aluminum sulphate. ph os solution is 3.8 by adition of caustic can I precipitate out as aluminum hydroxide and then reacidify to 3.8?
thanks,

Tom Martin
researcher,Hobbyist - Ankleshwar, Gujarat, India

I am eager to get reply of question 43050

Tom Martin
reasearch - Ankleshwer, Gujarat, India

Tom, you need to raise the pH of your solution to 5.5(?--check that to make sure its correct) and this will precipitate out out the aluminum. Raise the pH with Nickel Carbonate or you could try using Lithium Hydroxide. First transfer the solution to another tank. Raise pH let it that way, heated, agitation on, then let it settle for a day or so, then filter and return the bath back to the plating tank. Bring pH back to acceptable range with sulfuric acid and titrate solution for Nimetal, etc...

A quick check for aluminum contamination is to run a Hull Cell: 2A/10min you will see a high current density haze if you are grossly contaminted.

J. Ott
Plating Shop - Middletown, PA