As far as I can tell, sand isn't added by that GT_RecyclerBlacklistLoader class, but I tracked down why it's blacklisted - in the Materials enum, it's given a subtag of "NO_RECYCLING", and so are snow, ice, water, stone and glass. Thus regardless of the config options in disablerecipes, anything GT recognizes as being made of those materials will be blacklisted for the recycler. I think items that are less than 1 ingot worth of material (such as nuggets and small and tiny dusts) are also blacklisted, which would make it a bit overwhelming to look through the entire blacklist.
Well, as I mentioned it before, that does not make much sense to me. Shouldn't the recyclers be a reasonable way to get rid of materials and resources I don't need?
Then it makes no sense to blacklist most of the less useful but plenty available items/blocks that anyone has way too much of in his inventories just because of playing Minecraft normally.
If I don't want to have a misuse of machines as easy filler for the recyclers, well, then I should not create them in a way that they can be misused easily. Lava to make obsidian and cobblestone are more then enough around there to be mined easily.
Instead of creating a machine producing them infinitely a machine that only converts them vice versa or that at least consumes the source materials would have been way more reasonable.
A converter machine for example should require a source block/liquid (either stone, cobblestone, lava or obsidian), energy and water to do the conversion.
That way I reach both goals - an easy way to get obsidian (cobblestone just needs to be mined) and no misuse of my machine.
