Slightly off topic, A big load off my sholuders

[burleymike]

For over a week I was trying like a mad man to find some mineral wool to put around my fireplace firebox before installing the insert. I could not find anything within 75 miles. I finally decided to take some from my attic. As I was scooping some of it into a bag I kept seeing little shiny mica like flakes mixed in. Something about those shiny flakes seemed odd to me since all the photos of rockwool on the internet I had seen did not have any shiny material.

I did some research online and became quite worried that my attic might be full of asbestos contaminated vermiculite mixed with the rockwool. I contacted a lab and talked with the guy that handles asbestos testing. He said in the 4 years he has been with the company he only encountered asbestos in rockwool once. He has never seen rockwool with shiny flakes like that and he said that there is a good chance it could be vermiculite.

I sent in a sample of the rockwool Friday morning and I got the results today. It has no asbestos, those shiny flakes are indeed mica. Odd thing is 10% of the sample has cellulose mixed in with it as well. Now I can sleep a lot better knowing I have not been crawling around in a attic full of asbestos tracking the dust into the house.

 

[fishingpol]

Did you find out what the purpose of the mica is for? I know old baseburners stoves use mica for windows. Maybe it was a form of fire retardant?

 

[burleymike]

I had one batt of rockwool and the company name and address were printed on the craft paper. The batt at least came from Pueblo Co which had or maybe still has a steel mill. From the color of the rockwool it is probably from steel making slag. I am guessing some of the minerals they probably added were rich in mica which has a quite high melting tempature that would explain how it was left over like that.

 

[ROBERT F]

The batt at least came from Pueblo Co which had or maybe still has a steel mill.

They do still produce steel< and the nickname of pueblo colorado is "the steel city".

 

[burleymike]

I was not sure if they were still in business, my Grandpa worked for CF&I in the 1920's until the war ended. I have not been out there in nearly 20 years now.