Strontium Nitrate

With our first trial, we wanted to check the grindability of the sample with a coarser bottom sieve. We used the 0,5 mm trapezoidal perforated bottom sieve and started to feed the sample continuously into the feeding funnel while the mill was running at maximum speed (4000 rpm).

The grinding sound was typical. Only a tiny amount of fine sample dust escaped the filter house above the collecting vessel. For a desired amount of 25 kg, we would recommend using the optional 30 liter collecting vessel.

Because the feeding funnel contains a special metal sheet to avoid particles flying out of the grinding chamber, the max. size of sample is limited to ~ 20 mm length and 10 mm diameter. Once, we mobilized interlocked sample inside the feeding funnel with a stick.

After exactly one minute, we interrupted the grinding process and checked output and grinding chamber. From 2050 grams we fed, already 1975 grams of sample was found inside the collecting vessel. A lot of fine sample dust stuck to the filter house above. Inside the collecting vessel, a few grams stayed attached to the grinding set. The bottom sieve was not significantly clogged with sample. Surely even higher amounts of sample can be ground this way, too.

It is hard to estimate the possible amount of sample before a cleaning step will be required. Eventually the desired 25 kg can be ground in one batch only. It is also possible using the kit to attach a sample exhauster (16.6810.00) and / or combine with our optional high-performance cyclone separator with a large collecting 60 liter collecting vessel.

After result one, we exchanged the bottom sieve against a bottom sieve with 0,25 mm trapezoidal perforations. We fed sample slowly into the feeding funnel. After a few seconds, fine sample dust escaped the feeding funnel. We interrupted the grinding process after 30 seconds and inspected the grinding chamber. A lot of sample stuck to the grinding set and also closed > 75 % of the bottom sieve perforations.

A comminution of this sample to < 250 µm is not possible.

For intensive cleaning, the grinding chamber and rotor were taken out and washed with hot water. Afterwards, the equipment was dried to prevent corrosion (especially when a hardened steel quality was picked).