IKA A 11 basic Mode D'emploi page 20

seeds, salts, slag.
Tough grinding material must be cooled, for example by adding
pulverized dry ice to the grinding container.
The grinding material must be initially broken down into pieces
with a diameter of 1cm (feed granularity 10 mm, the size of a grain
of corn is ideal).
Cutting milling:
The A 11 basic with the A 11.2 cutting blade reduces bulky, ela-
stic fibrous and soft materials with high cellulose content. Mixed
goods such as trash must be free of iron and non-iron metals. the
feed material must not be too moist or fatty. Otherwise the mate-
rial may adhere to the sides of the grinding container.
Following is a list of some materials that can be reduced:
Leaves, fibers, spices, grain, hops, cardboard, paper, hay, plastics,
tobacco, peat, feed goods, dough and roots.
The feed granularity should be no greater than 10 mm.
For moist and sticky feed material (for example fish, meat), reduc-
tion is also possible by adding water. This prevents the grinding
material from adhering to the walls of the grinding container, and
the blades continue to engage the grinding material.
Note: If water is added, the grinding container should not be filled
to more than 50% capacity. The mill must only be used in an
upright position in this case (must not be agitated or turned on its
head).
Please note: Materials that are not listed above should only be
reduced in the A 11 basic after confirmation from IKA, especially
if there is uncertainty about the danger of explosion (dust explosi-
on as a result of electrostatic charge).
Working with coolants
Please follow the safety instructions.
Crushing causes the mill feed to heat up. This may not always be
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desirable as the mill feed can change when heated (e.g. increased
oxidation, loss of moisture, evaporation of volatile components,
etc.).
It may only be possible to crush mill feed which is viscous or has
a high fat content by embrittling using coolants.
The A 11 basic offers two cooling processes:
Dry ice cooling (CO ): approx. –78 °C
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First put the feed product into the grinding beaker and then add
crushed dry ice. Thoroughly mix the dry ice with the mill feed.
Only attach the drive once the dry ice is completely vaporized,
otherwise high pressure can build up in the grinding chamber.
Please note that the mill feed heats up again extremely quickly
during crushing (it may reach room temperature again after
approx. 10 seconds of grinding). You may have to repeat the pro-
cess several times if the product is not adequately crushed after
one cooling process.
Liquid nitrogen cooling (N ): approx. –196 °C
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Please follow the safety instructions for liquid nitrogen cooling in
particular and always wear your personal protective equipment
(safety goggles, protective gloves, etc.).
Use a beater (A 11.1 or A 11.3) to crush mill feed embrittled with
liquid nitrogen. The cutter (A 11.2) is not recommended for this
purpose (becomes blunt quickly).
Grinding beaker A 11.5 (included in delivery) is made of fluoro-
plastic (ETFE) with a stainless steel insert.
First pour the feed product into the grinding beaker Pour liquid
nitrogen into the grinding beaker using a suitable Dewar vessel,
ensuring that the sample is completely covered or swimming in
liquid nitrogen.Only attach the drive once the nitrogen is comple-
tely vaporized, otherwise high pressure can build up in the grin-
ding chamber.
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