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Crystal formation in sodium and potassium hydroxide solution

I have a solution composed of 12% W/V SODIUM HYDROXIDE AND 12%W/V POTASSIUM HYDROXIDE PLUS 2.3% AVAILABLE CHLORINE (FROM SODIUM HYPOCHLORITE)
MY PROBLEM IS THAT SOMETIMES AFTER TIME I GET CLEAR ELONGATED CRYSTALS PRECIPITATING IN THE SOLUTION.HOWEVER THIS DOES NOT OCCUR WITH EVERY BATCH.THE CRYSTALS ARE WATER SOLUBLE.

DONAL O DUBHGAIN
DETERGENT PRODUCT FORMULATION - IRELAND
2005

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Open top solutions of NaOH or KOH will take CO2 out of the air and form sodium or potassium CARBONATE which is a white crystal that floats on top. Otherwise I don't know.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2005

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First of two simultaneous responses --

You may try diluting your solution a bit and if possible raising the temperature a bit.

Guillermo Marrufo
Monterrey, NL, Mexico
2005

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Second of two simultaneous responses --

You may want to check the following;

1.Temperature of the solution. - Cold solutions may form crystals.
2.Check the water being used to make the solution. - If you are using tap water, the sodium and potassium ions may be replacing the calcium in the hard water causing crystals to form. In this case an inline water softener can be used on your feed water.

Good Luck!

Jim Sivertsen
Refining & Alloys - Alden, N.Y., USA
2005

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Take out some of the crystals and drop into weak acid. If they fizz vigorously then it is carbonate. Take to a lab and ask to find out if Na,K, if you want. If they are highly sol then prob not Ca, Mg

Geoffrey Whitelaw
- Port Melbourne, Australia
2005