Our processes are:

1. Carbon black (D50 is ~100 micron or larger) was heated in 140 C dryer to remove the moisture.

2. the grinded carbon black was fed into high pressure pan mill to grind to 0.7 micron.

3. An ethylene/propylene gas stream picks up the fine carbon black and transports it to a reactor. This stream is about 600 psig. The reactor is controlled at 490 psig pressure and 72 degrees C.

4. The grinded carbon black was supposed to coat on the surface of the products. However, for any reason, our final products have some 100 micron carbon black particles some time (most time is ok).

I thought that the agglomeration could be happened in the reactor, the stream pipeline or anywhere. Maybe the pan mill is also an issue. But we do not know where the problem is.

If you can help us to find where the problem is, we will appreciate it a lot.

By the way, the whole process I introduced above is sealed, we can not take any samples except raw materials and end products. So I am wondering if it is possble to build a high pressure cyclone sampler (or similar equipment) on gas stream line to get carbon black sample and measure its size distribution?

Until now, we measure the size distribution for raw carbon black. The "bad" carbon black showed the wider size distribution if the end products have agglomerated carbon black. But it may not be an issue.

Thanks a lot. ■