When Mekanism isn't actively included in a modpack, dirty dusts, clumps, etc. (which have other non-Mekanism recipes) become completely unusable. As soon as Mekanism is added, suddenly both ATO and Mekanism add dirty dusts.

ATC only takes care of recipe compatibility and has no influence on existing items or not.

it can also happen that if you do not combine the right mods, you can produce items such as clumps or shards, but then you cannot process them further because your installed mods do not provide suitable machines.

but there are some mods such as OriTech that offer alternative processing methods such as Mekanism

(Comment: Moved from AllTheMods/AllTheOres#89.)

The issue here is something different: I have Create in my pack. I want to crush, say, Iron Clump into Dirty Iron Dust in the crusher, but the actual Dirty Iron Dust item does not exist in All the Ores.

However, after adding Mekanism, the All the Ores mod ALSO adds Dirty Iron Dust...
And then I can just produce Dirty Iron Dust WITHOUT USING MEKANISM.

As I said, this is not within the scope of my mod, I only add recipes here and do not change anything in the registry, that would have to be done by the ATM team if so

Got it. Thanks!

I will release a version today that fixes the problem and also registers the mekanism compatibilty items even if mekanism is not loaded. :D