Document zoM7pMnBNZJ7589OMKGRDX5v0

fr8ZK30HN3a OS i iVi' Ji K 0 !' KICK *: 0 M M t1 / \ *; \ T I 0 N -s , . To: S,ee Distribution cc; SYSTEMS CaffjDEf'tm' From: AX Davidson Subject: Vermiculite Ore - Asbestos ijpnitoring s?i Date: June 23, 1980 . Samples of vermiculite ore rcm Grace Libby, Virginia, and American VermicuHte (African) prepared per the Grace concentration scheme were .|ufcmitted to McCrone Associates for asbestos analysis on May 7, 1980. purples were analyzed by x-ray diffraction and polarized light njicrosoopy/dispersion staining. Results are as follows: A. X-ray diffraction studies indicated the presence of amphiboles I in samples--African (-100M), Virginia Pole Bam(-IOOM) , Virginia " Marysville (-70+10QM), Virginia Marysville (-100M) , and Libby I Marysville(-10OM). I Optical Microscopy studies revealed the presence of 0.5-1% tremolite- i actinolite in samples | 1) Virginia Pole Bam(-IOOM) 0.013 to 0.026% g 2) Virginia Marysville(-10OM) 0.025 to 0.050% | 3) Libby Marysville(-100M) fll 0.006 to 0,0112% i Per McCrone "the tremolite-actinolite in these samples is of the l massive variety, however, much of it has cleaved to form fragments with aspect ratios of 3:1 or greater." The percentages shown above are oonverted to represent percent in total sample. | The indication, of tremolite-actinolite in the African (-1QQM) fraction | was not confirmed by optical microscopy. Also, the optical studies | revealed the presence of several percent hornblende in the Virginia| Polebam(-IOOM), Virginia-Marysville (-100M) , and Virginia-Marysville I (-70tl00M) samples. 'h | Cft. White-gray particles were removed from another portion of the Grace- i Libby vermiculite ore used above. The particles were examined by " optical microscopy by McCrone and found to "consist of approximately i 90% tremolite-actinolite (probably actinolite) and appears to be of i the asbestiform variety." i D. The optical microscopy studies did not detect the presence of g asbestos minerals or other amphiboles in any of the African ore * fractions or in any of the larger mesh Virginia and Libby fractions. Distribution *Pete Griffin !" John Kilsheimer John Kennedy John Cleveland ji Eon Wietelmann V` 3 Sarge Chamberlain Dick Gruenbaum Mike Kelty Gary Smith 1