We have a Spex 8000 Mixer Mill which we have had for about two years.
It experiences heavy (and sometimes abusive) use from geology students
and faculty and considering that it has held up quite well. We have
the steel and alumina vials. Regarding contamination, users are told
to clean the vials before and after use, and we recommend that they
grind a little bit of their sample (or clean quartz) in there first to
pre-contaminate the vials. Obviously the steel vials contaminate
particularly with iron. I believe one of our students has examined
the contamination issues for XRF pressed powder pellets, which if you
are interested in I can see if I can dig up. The alumina ones have
minimal contamination that we've noticed, but they are fragile, and we
did have a failure, most likely due to repeated volume overloading and
too large initial particle sizes of hard materials. Following the
recommended sample loading instructions for each vial type should be
emphasized to the users. They do have a propensity to make a mess
when one is not careful in the unloading process.
On the mill itself, the rubber pads in the vial clamps do wear out
over time and they will need to be replaced.
Karen J. Spaleta
Advanced Instrumentation Laboratory
University of Alaska Fairbanks
PO Box 755780
Fairbanks, AK 99775-5780
e: [log in to unmask]
On Fri, Jan 22, 2010 at 4:19 AM, Pappas, Richard Steve
(CDC/CCEHIP/NCEH) <[log in to unmask]> wrote:
> Does anyone have experience with Spex 5100 or 8000M Mixer Mills, or
> similar competitors' products?
> The Spex equipment is certainly more affordable than others I have seen,
> but that worries me.
> The Spex mill seems to have sample vials and grinding balls made from a
> wide variety of materials:
> Agate, polystyrene, polycarbonate, polyethylene, stainless steel,
> "hardened steel," tungsten carbide, zirconia, alumina ceramic vials
> Methacrylate, zirconia, tungsten carbide, stainless steel grinding
> Some seem attractive from a metals contamination standpoint, but I
> wonder about effectiveness, as well as if the machine does a good job
> without falling apart in two months or contaminating samples like crazy.
> R. Steven Pappas, Ph.D.
> Emergency Response & Air Toxicants Branch
> Centers for Disease Control & Prevention
> 4770 Buford Hwy. NE, M.S. F-44
> Atlanta, GA 30341-3717
> Phone 770-488-4661
> [log in to unmask]