8530 Shatterbox
Page 14 of 28
SPEX SamplePrep LLC January 2010
5.1.2
Choice of Grinding-Container Size
There are four sizes of Shatterbox grinding container: small, medium, large, and extra large. To
pick the correct size it is necessary to know the minimum amount of sample you have to grind,
its approximate density, and the fineness of grind desired, as each may affect your final choice.
The typical sample capacities of each container type are given below in grams, assuming a
sample of the density of quartz sand, rock, etc. (approx. 2 to 3-1/2) and the requirement to
pulverize the sample to around 325 mesh (44 microns). The sample capacity volume RANGE,
which is much broader, is given in ml. If you are unsure which Shatterbox grinding container to
select, consult our product specialists. You can also send your samples in for evaluation and
test grinding.
Small:
8507 Small Hardened Steel and 8508 Small Tungsten Carbide grinding
containers. Each has a puck-shaped grinding element. Typical sample capacity
8-12 grams, sample volume range 5 - 15 ml. Requires 8507R Rack to operate one
8507/8508 or three simultaneously.
Medium:
8505 Alumina Ceramic and 8506 Zirconia Ceramic grinding containers. Each has
a puck-shaped grinding element. Typical sample capacity 20-30 grams, sample
volume range 15 - 40 ml.
Large:
8501Hardened Steel and 8504 Tungsten Carbide grinding containers. Each has a
puck and ring. Typical sample capacity 40-60 grams, sample volume range 20 -
70 ml.
Extra Large:
8521 Large Hardened Steel grinding container, with puck and ring. Typical
sample capacity 60-100 grams, sample volume range 30 - 120 ml.
The sample volume ranges given above are estimates, not absolute limits. The upward limit on
the weight/volume of a given sample for a given grinding container is really determined by the
point where the mill stops grinding the sample satisfactorily. This limit can vary with the type
of the sample and its particle size. The lower limit on the size of the sample is usually reached
when the sample becomes highly contaminated and is hard to recover. (If very little sample is
ground there is a lot of direct contact between the grinding element or elements and the
container, and under these conditions the tungsten carbide and ceramic grinding containers are
more likely to become chipped.) Avoid grinding large chunks of sample, as these can either jam
the grinding container or damage it; even if they grind satisfactorily they will probably not grind
consistently. We recommend reducing the feed size to at least 1/4" for the tungsten carbide
and steel grinding containers, and to 1/8" for the alumina and zirconia ceramic grinding
containers.
When developing a procedure for your combination of Shatterbox and grinding container, try a
sample size near the middle of the given range(s). Grind for two minutes in steel or tungsten
carbide, or four minutes in alumina or zirconia. If grinding is not satisfactory but the sample is
not caking, try increasing the grinding time or decreasing the sample size, or both. If caking
occurs, consult the
Handbook of Sample Preparation and Handling
for information about
grinding aids.