Manganese Alloy

Both pieces of sample are small enough to be fed to a Model I (1) jaw crusher. If samples up to 8-9,5 cm are desired to be fed, we recommend using model II (2). The jaw crusher was equipped with crushing jaws made of hard metal tungsten carbide. For this kind of sample, also jaws made of steel can be considered (rapid crushing with a smoother grinding sound).

We fed the smaller piece of alloy with a gap of setting of 8 (mm). The sample was ground into pieces rapidly. After only 2-3 seconds, no further grinding sound was recognized. Fragments up to a length of ~ 2 cm can be found inside the collecting vessel. With such a start size, sample can be fed to a Disk Mill PULVERISETTE 13 as desired (see result 2). Even smaller grinding results can be achieved (see result 4 with gap setting of 0,3 mm).

We used about 200 grams of output of result 1 for our comminution trial with our Disk Mill PULVERISETTE 13 premium line. Also by this trial, the hard metal tungsten carbide disks are not necessary for comminution, but we recommend using the hard metal tungsten carbide, because they have a much longer durability (compared to steel grinding disks).

Sample was fed and ground within 15 seconds. Typically, ground sample only needs to comply to the gap setting of 0,05 mm in one dimension to pass the grinding chamber. Therefore, even longer and wider particles can be found inside the collecting vessel. After 15 seconds, a typical residue remains inside the grinding chamber (8 ± 3 grams). Removing of electrostatically charged particles can be performed rapidly by vacuuming with a soft brush. There was no sticking of particles inside, so even higher amounts of sample can be ground this way.

For testing purposes, a small amount of sample was sieved by our Vibratory Sieve Shaker ANALYSETTE 3 Pro and test sieve with 160 µm mesh. We found 57,6 % of particles < 160 µm; 42,4 % remained > 160 µm. This is a typical result. This is a brittle kind of alloy; concerning ductile alloys much longer particles can be formed.

If most particles should be ground to < 150 µm, most likely a Vibrating Cup Mill PULVERISETTE 9 should be used. With such a type of mill, brittle samples can be comminuted very fast to a level of fineness < 100 µm.

By dry grinding of 70 grams of pre-crushed sample (from result 2) within 2 minutes, already 92,8 % of sample was ground to < 160 µm. The sample was sticking only slightly at this time,so even longer grinding times can be set to improve the resulting fineness.

If more of sample is fed, the required grinding time will get longer for sure.

We like to mention that finely ground metal dust gets more reactive to oxygen. Depending on type of alloy, fineness and introduced heat, in some cases, metal samples started burning.