USGS Open-File Report 02-371, Geochemical Sediment Analysis Procedures, Ball Mill Grinding Procedure

BALL MILL GRINDING PROCEDURE
Materials Required: Agate Grinding Vessel Ball Mill Grinder Plastic Spoon Weighing Paper Compressed air Small Brush Sediment Sample Sharpie
Remove grinding vessel from the drying oven. *Do not leave the plastic spoon in the oven for extended periods of time because it will warp.
Assemble the grinding vessel in this order: Bottom cap, o-ring, 2 agate balls, center cylinder.
Empty the 10 dram poly vial sample into the agate grinding vessel (approx. 3-5 g). Add the second o-ring and top cap.
Place grinding vessel in the ball mill grinder and screw tightly to hold the vessel in place.
Start the machine by closing the door of the ball mill grinder.
While the sample is being ground, use compressed air to remove excess sediment left in the original sample container. After 5 minutes, remove vessel from grinder by opening lid and unscrewing the holding mechanism.
Empty the sediment onto a piece of weighing paper.
Use the plastic spoon to scrape off the sediment adhering to the vessel or use the small brush.
Pour the ground sediment back into the vial and set the grinding vessel aside for acid washing.
Label the vial with a "G" to denote that it is ground and return sample to box.

Geochemical Sediment Analysis Procedures, Open-File Report 02-371