Vertrel XF, a DuPont product, is finding increased acceptance as a grinding aid. A fluorocarbon fluid, it prevents sample caking during grinding, and quickly evaporates from an open grinding container without leaving any residue. (Users 首ld of course consult the DuPont Material Safety Data Sheet to determine incompatibility with other materials.) Our experience is that the grindability of almost any sample is enhanced by the use of Vertrel XF, contamination is lowered, and the grinding container is easier to clean. Typical XRF samples such as cement, rock, clinker, and similar material can be routinely ground below 10 microns. The technique that follows was pioneered by John Anzelmo and colleagues at Bruker AXS,* and is here adapted for SPEX CertiPrep, Inc. equipment: in an 8501 Hardened Steel Grinding Container load together 10 grams of sample, 2.5 grams of 3644 Ultrabind binder, and 7 ml of Vertrel XF. Grind in an 8515 Shatterbox for 2.0 minutes, then open the grinding container in a hood until the Vertrel XF has evaporated. Prepare a 3614 40mm Pellet Die with a flared 3617 Spec-Cap, and transfer the ground sample/binder powder to the die. Press at 20 tons for 0.3 minutes in a 3630 X-Press. *Anzelmo, John; Seyfarth, Alexander; and Arias, Larry (2001). SPEX 3636全自動(dòng)壓片機(jī)