1.18...

I need nickel and aluminum to make a blast furnace... and a blast furnace to get nickel and aluminum.... dafuk?

Not a bug. Put Raw Iron/Copper/Gold into the Industrial Grinder to obtain Nickel Nuggets. EDIT: I meant Industrial Centrifuge

More in-game documentation coming soonish.

Install REI/JEI to see where you get these from.
Can also get them from Raw Iron/Gold/Copper in an Industrial Centrifuge.

Industrial Grinder requires steels to craft, so Industrial Centrifuge is the only route to obtain nickel before steel age?

I figure it out... there was a recipe hidden in JEI* i didnt see.
You can make industrial centrifuge without aluminum (When i opened the issue, i saw only the recipe with aluminum)
I can get niquel bits from iron raw iron.