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How much cadmium in a cadmium bolt?

We have a load of hazardous dust that is 2.2 ppm of cadmium. The box weighs 13 tons. I figure that it contains about .06 lbs of cadmium in it. My question is, how many bolts would I have to melt to give me the 2.2 ppm of cadmium. How much cadmium is in a cadmium coated bolt?

matt cox
- waterloo, Iowa, USA
2003

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First of two simultaneous responses --

Not enough information to calculate, but here's how to estimate: First, select a typical bolt size and thread type. Use a Machinery's Handbook and figure out the total surface area of the bolt. The bolt was perhaps plated per Federal specification, AMSQQP416, Class 2, Type 2 (0.0003" Cd + yellow chromate). The density of Cd is 0.313 lbs/cu. inch. Hence, 0.06 lbs is enough for 639 sq. inches of plating. Divide by the bolt area and voilà tout, the number of bolts.

Your dust also has some Cr, but likely at a lower concentration than Cd.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2003

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Second of two simultaneous responses --

Matt, figure on the cadmium plating averaging 0.0003 to 0.0005 inch thick. You know the size of bolt you're talking about, so your rough calculations should be reasonably accurate.

Good luck!

Lee Gearhart
metallurgist - E. Aurora, New York
2003