There are at least 2 Silicon items, that i'm aware of: one from Nuclearcraft and one from Refined Storage. The Nuclearcraft one has a decent recipe involving the Arc Furnace, but the Refined Storage one can be obtained just by smelting Nether quartz and can be used for anything so there is no reason to ever use the arc furnace recipe for Si.
There are at least 2 Silicon items, that i'm aware of: one from Nuclearcraft and one from Refined Storage. The Nuclearcraft one has a decent recipe involving the Arc Furnace, but the Refined Storage one can be obtained just by smelting Nether quartz and can be used for anything so there is no reason to ever use the arc furnace recipe for Si.