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Chrome salt consumption for 1 sq ft by 1 micron thick
March 5, 2014
Q. Dear sir,
Please let me know chrome salt consumption for 01 sq ft for 01 micron.
A. Hi Nitin. A square foot is 144 square inches, and a micron is 39.4 millionths of an inch ... so you're talking about .00567 cubic inches of chrome. Chrome weighs about 0.26 pounds per cubic inch, so you have .00147 pounds of chrome.
The molecular weight of H2CrO3 is 102 and the atomic weight of chromium is 52, so you'll consume about 102/52 x .00147 = .00288 pounds of chromic acid.
But the thing is, the amount lost to mist evolution and the dragout of the viscous chromic acid are liable to make the amount consumed by plating nearly into roundoff error. If you will explain your situation and tell us what you are involved with, we may be able to give you some helful info. Good luck!
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April 4, 2014
A. Usually we do not calculate the consumption in this way -- one reason is because of the uneven thickness distribution.
A better approximation you will get from experience with the bath.
Plating complicated shaped parts will result in higher drag-out but also higher thickness differences.
Other aspect that you have to keep in mind is the evaporation.
- Oradea, Romania