Document xj0zK0kJEGn7ZD5okwpGa6Zb0

"f WRG 000175 Johns-Manville RESEARCH n ENGINEERING CENTER P.O. BOX 159 MANV11LE, NEW JERSEY TELEPHONE: 12011 RANDOLPH 2-9000 September 18, 1968 Mr. E. Lovick ZONOLITE DIVISION W. R. Grace & Co. P.O. Box 609 Libby, Montana 59923 Dear Mr. Lovick: An Industrial Hygiene Survey of the Libby, Montana Mine and Mill was conducted during the week of July 15, 1968. The survey was conducted by R. D. Hindraarch, Supervisor, Industrial Hygiene, Johns-Manville Products Corporation,with assistance from P. Kostic, Safety Administrator, Dewey and Almy Chemical Division. Prior to the survey.eleven samples of vermiculite were forwarded to the Johns- Manville Research Center for analysis. All of the eleven samples were collected on April 24, 1968, and are as follows: Sample Number Sample Description 1-A Vermiculite Concentrate Expanded Vermiculite Vermiculite Concentrate 2-B Expanded Vermiculite 3-A Vermiculite Concentrate 3-B Expanded Vermiculite 4-A Vermiculite Concentrate 4-B Expanded Vermiculite 5-A Vermiculite Concentrate 5-B Expanded Vermiculite Raw Ore Mill Feed Vermiculite X-ray powder diffractometer diagrams taken for qualitative analysis of these samples show them all to be mixed layer minerals of either biotite-vermiculite or hydro biotite-vermiculite composition. No crystalline silica was identified from these patterns and quantitative analysis show these samples to contain less than one per cent quartz and less than one per cent cristobalite. t Mr. E. Loviek 26174 -2- September 18, 1966 The second part of tha analysis eonaiatad of examining the samples by the Petrographic examination failed to ahov any qoarts, erlatoballte, or chrysotlla, bat did ehaw snail amounts of a material having fibrous^or apllntarycharacfsHstlaa., and ahoving optical properties within the range of values reported for tramollte. the amount of tremollte detected was of the order of about 1 to 2 percent In the cooeeatrat< aamplea, and about 1 percent In the expanded samples. Upon completion of this phase of the analysis, a meting was held between P. Koatie and R. D. Hlndmarch to discuss the lew percentage of tremollte found In the aamples. It was then decided that during the survey, hi-volune air samples should be taken to determine the amount of tremoliee In the ambient air. The description and results of the hi-volume sample follows: Sample Number Sample Description Tremollte In Percent 1 First Floor - center of room 23 2 Second Floor - center of room 17 3 Third Floor - center of room 16 4 Fourth Floor '- center of room 14 5 Fifth Floor - center of room 12 6 Sixth Floor - renter of room 22 Petrographic examination of the above six samples showed a micaceous mineral resembling blotlte, and substantial amounts of tremollte. Samples 1,2, and 6 appeared somewhat higher in tremollte than did Samples 3,4, and 5. The method failed to show any free silica minerals or chrysotlle asbestos. X-ray powder diffractometer diagrams taken for qualitative analysis of these samples show them all to be mixed layer minerals of either biotlte-vermiculite or hydroblotltevermlcullte and a minor amount of tremollte. Crystalline silica was not Identified In these samples but Interference of the tremollte pattern made It Impossible to be certain that no quartz was present. The threshold limit value for tremollte Is 5.0 MPPCF (million particles per cubic foot of air). Based on the above analysis it would Indicate that this threshold limit value would be applicable to your operation. Simultaneously, as hi-volume air samples were being taken, Implnger samples were obtained of the dust In the atmosphere. This survey was conducted according to the standard procedure for sampling and counting dust adopted by the Fifth Annual Meeting of the National Conference of r^vemmental Industrial Hygienists In 1942. The results of the survey are as follows: 26175 Hr. E. Loviek 3- Saptamber 18. 1968 Station Humber Station Location First Sample oor^^ _ fast of 606 Elevator" First Floor - Approximately 10' 1.4 East of 109B Hi-Grade Dryer Burner 2-1 Second Floor - Approximately 5* East of 607 & 608 Elevators 8.6 If 2-2 Second Floor - Approxlaately 12' East of 602 & 603 Elevators 1.0 I in front of Switchboard 2-3 Second Floor - Approximately 5' South of 234 & 235 Vibrating Screens 10.1 tl 3-1 Third Floor - Approximately 4' East of 606 6 607 Elevators 4.5 If 3-2 Third Floor - Between 304 Roll Crusher & 602 Elevator at Building Column 6.0 If 3-3 Halfway between 332 Elevator 6 329 Screw Conveyor 2.5 If 4-1 Fourth Floor - Halfway between 606 Elevator & 418 Vibrating Screen 3.4 I 4-2 Fourth Floor - Halfway between 410 Vibrating Screen-6 Switchboard 3.2 I 4-3 Fourth Floor - Approximately 10' East of 619 Elevator 2.8 II 5-1 Fifth Floor - Approximately 5' North of 501 & 502 Vibrating Screens 4.0 it 5-2 Fifth Floor - Approximately 5' 5-3 West of 597 Vibrating Screen Fifth Floor - Approximately 5' 3* -A it South of 512 Vibrating Screen 1.8 it 6-1 Sixth Floor - Halfway between 615 Elevator and 611 Drag 5.4 ii 6-2 Sixth Floor - Approximately 5' East of 608A Screw Conveyor 5.3 ii 6-3 Sixth Floor - Halfway between 618A Screw Conveyor end Switchboard 5.0 *i Sheet Metal Shop - center of room 1.2 ii Machine Shop - center of room 0.6 Warehouse - center of room 0.5 Expanding Plant - at bagging unit 0.9 i it Second 8aas>le 1.3 8.4 " 0.9 10.5 " 6. 4 " 6.1 1.4 " " 2.7 " -r. 3.1 7L~3.6 " 5.7 " 4.4 " 1.6 " 5.0 " 5.3 " 3. i " 1.2 '' 0.9 " 0.7 " 1.3 " C. Loviek )_ -4- Septeaber 18, 1968 Station Ifusber * Station Location 4mn MP Inaida Euclid Truck - from lUianum t-ffraa w Cab at Pit Inaida Truck Cab at Lower Bln whlla loading Inside Truek Cab at River Bln while unloading Inside Skip Operators Control Booth at Mill ftrwt Sample 3.0 " 4.6 " 5.4 " 3.9 " Saeond Safi During the survey the following conditions were noted: _ A. Numerous visible dust leaks fron aqulpaent on all floors of the Mill. B. Material, periodically falling off conveyors onto floor. C. Moderate' to heavy accumulation of dust on floors, uachlnery and building structure. D. The use of brooms and air hoses for cleaning purposes. Visible clouds of dust drifting through the open windows creating o uoderate to heavy atmosphere of dust throughout the Mill. Photographs were taken, where possible, to better define the sampling areas. They ere attached and numbered to correspond with the station locations which are listed on pages 3 and 4 of this report. ____ Also attached ere drawings of the separate floors af the Mill with the station location listed. Very truly yours. RDH/aa Attach.(2) cc: R. W. Sterrett ZONOLITE DIVISION W. R. Grace & Co. Merchandise Mart Plata Chicago, Illinois 60654 P. KostlcV ^ ZOBOLITE DIVISION W. R. Grace & Co. 62 Vhltteraore Avenue Cambridge, Mass. 02140 (With Attach.) Ralph D. Hindmareh, Supervisor Industrial Hygiene Photo 2-1 Photo 2-2 Photo 2-3 Photo 3-1 261^3 Photo 3-2 Photo 3-3 Photo 4-1 Photo 4-2 261 Photo 5-2 Photo 5-3 .vv' .. - Photo 6-1 Photo 6-2 Photo 6-3 Shoot Motal Shop *7T1 XS-r f. :9 - ---- Expandlng-PUnt l