Flux Fusion

With a start size of sample up to ~ 50 mm, a direct feeding of sample into a Disk Mill PULVERISETTE 13 is not recommended. Next to manual pre crushing, it is also possible using a Jaw Crusher PULVERISETTE 1 (Model I or Model II). Just for demonstration, we used a Jaw Crusher with steel equipment.

With smallest gap position (0,3 mm for premium line jaw crushers), it took about 55 seconds until the batch of 500 grams was comminuted and grinding sound vanished.

Typically, the gap will open up to ~ 2 mm while operating. Therefore, depending on brittleness and sample properties, up to ~ 10 mm long fragments can be found. Such a pre-ground sample could be comminuted fine with e.g. PULVERISETTE 13 (see result 2).

Cleaning was performed rapidly by vacuuming with a soft brush.

After pre crushing, the sample can be fed into a Disk Mill PULVERISETTE 13. Samples only need to comply the adjusted gap in one dimension; therefore, much longer and wider fragments can be found inside the collecting vessel.

To achieve a d95 < 0,5 mm, we recommend using a gap setting of 0,1 mm or finer. The complete pre crushed sample of result one was used and fed slowly. It took 8 minutes until the grinding sound vanished completely.

We sieved a small quantity of the grinded material and found 99,9 % of sample already < 500 µm as desired. It is possible to improve the grinding result with smaller gap setting (premium line, down to 0,05 mm gap); or it is possible to improve throughput by adjusting wider gap settings. The optimum setting needs to be figured out with several trials.

For rapid cleaning after usage, we recommend vacuuming with a soft brush. Next to this setup, also different other types of mills can come into question for metal free comminution. We would recommend using a Planetary Mill PULVERISETTE 5 classic line (with two bowls of zirconium oxide), or a batch wise comminution with Planetary Mono Mill PULVERISETTE 6 classic line (see result 3).

For our last trial, we used a Planetary Mono Mill PULVERISETTE 6 classic line and the largest bowl of 500 ml total volume, made of zirconium oxide. For the flux sample fragments with a thickness about 3 mm, we recommend using grinding balls of 30 mm diameter (factor 10-20 is recommended). Eventually also 20 mm Ø grinding balls can be used when a sample is very brittle.

We started our trial with a limited speed of 550 rpm only. Higher speed setting might be possible to improve the grinding speed. We estimate that also this setup will show a fast comminution of sample. With 162 grams of fed sample, the bowl is filled by ~ 2/3. Most likely up to ~ 200 grams of sample can be fed; eventually a pre crushing will be required to reduce bulk volume of original sample.

After 30 seconds only, the sample appears to be ground fine, we used a small quantity of sample to determine particle size by sieving (with Vibratory Sieve Shaker ANALYSETTE 3 Pro) and found 82 % < 0,5 mm at this point.

We ground the sample for a further minute (90 seconds total grinding time) and checked level of fineness again. More than 99,9 % < 0,5 mm was present at this point. Also the sample slightly started sticking to the grinding set. We don’t recommend significant longer dry grinding times. Sample was packed at this point and we cleaned the grinding equipment, using a small portion of sand and water to grind for ~ 2 minutes.