Particles in a conveyor

[d4rk3lf]

I have to return to this topic.

I still cannot find a way to split the particle stream.  There are two kind of particles on the conveyor: those which dissolve and those which do not. How can I separate particles that don't dissolve. Those particles should eventually travel to junk trap while the rest are not visible after fracture operators.

All test operators are just for that. 
For testing particle conditions and send them out to do whatever you want. 
Test operators are the ones with orange colors. 
So you can split them with any test of your liking (and needs). 
You already split them once with "surface test"... and.. if you can do it also in this case, why don't ? 
There is also a simple split operator that can split particles to any percent (and some more variations of that). 
Time test is also test operator... 
And many more... 

Also, test operator always have output for you to connect them to new event, because whenever you split particles, they need to go somewhere... and that somewhere, in tyflow case is always new event. 
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I might be wrong, but looking at your last screenshot of your flow, it looks like you overcomplicated things too much, and it doesn't look too optimized. 
For example, I think you are using particle physics in cases where you don't really need it (where particles are basically dust and it doesn't matter if one particle dust collide to another. 
But I might be (very) wrong, and besides, part of learning is making overcomplex flows... I did it million times.