SPEX SamplePrep 8000 Series - 1 Introduction

8000M Mixer/Mill
Page 4 of 27 SPEX SamplePrep LLC January 2010
1.0 INTRODUCTION
The SPEX SamplePrep 8000-series Mixer/Mills are efficient, compact laboratory mills capable of
pulverizing samples in the 10-gram range. Functionally described as shaker mills or high-energy
ball mills, these Mixer/Mills shake containers back and forth approximately 1080 cycles per
minute (60 Hz model). These multi-purpose mills are capable of reducing hard, brittle samples
to analytical fineness, blending powders, making emulsions, and performing mechanical
alloying.
The vial, which contains a sample and one or more balls, is shaken in a complex motion that
combines back-and-forth swings with short lateral movements, each end of the vial describing a
figure-8. The length of that swing is the same as the internal length of a standard 8000 series
vial, about two inches. With each swing the balls impact against one end of the vial,
simultaneously milling the sample to a powder and blending it. Because of the amplitude and
velocity of the clamp’s swing, each ball develops fairly high G-forces, enough to pulverize the
toughest rocks, slags and ceramics.
The single-clamp 8000M Mixer/Mill, known simply as “the Spex Mill” to thousands of users, has
served spectroscopists and analytical chemists for over forty years. The clamp mechanism has
changed little since the earliest versions, simply because it has proven extremely durable. Many
of the earliest 8000 Mixer/Mills are still in service. An electronic 100-minute timer has replaced
the original wind-up timer and the mill’s safety features have been improved: the lid is now
locked down until the clamp stops moving.
8000-series Mixer/Mills have been used for pulverizing rocks, minerals, sand, cement, slag,
ceramics, catalyst supports, and hundreds of other brittle, often hard samples. Early in its
market introduction, the 8000 was used to grind samples, then blend them with graphite for
arc/spark spectroscopy; now similar samples are ground, then blended with binder before
being pressed into sample discs for XRF. The vigorous motion of the clamp is also excellent for
making emulsions, such as paints, inks and pharmaceuticals. 8000M Mixer/Mills have also
achieved notoriety for their ability to mechanically alloy small quantities of materials in fields
such as superconductor research.
For assistance in choosing the SPEX SamplePrep grinding or blending containers which would be
best for your application, please call SPEX SamplePrep at 1-800-522-7739 or 732-623-0465.