Found error in Wiki
Code
//Graphene out of Silicon and Graphite with Oxygen
import mods.gregtech.BlastFurnace;
BlastFurnace.addRecipe([<gregtech:gt.metaitem.01:2819>], <liquid:oxygen> * 1000, [<gregtech:gt.metaitem.01:2865>, <gregtech:gt.metaitem.01:2020>],
500, 480, 2000);
Silicon ingots is
<gregtech:gt.metaitem.01:11020>
not
<gregtech:gt.metaitem.01:2020>
And actually there must be no oxygen for reaction Si + C -> SiC.
With oxygen it would be Si + C + 4O -> SiO2 + CO2.
Actually the way to produce Graphene should have two steps:
1) Si + C -> SiC in Blast Furnace.
2) SiC -> Graphene in Laser Engraver
But i have no way to add new item unfortunately.
Upd
And seems like something wrong with second input parameter in GTTweaker-1.7.10-1.0.6.
Code
BlastFurnace.addRecipe([<gregtech:gt.metaitem.01:2819>], [<gregtech:gt.metaitem.01:2865>, <gregtech:gt.metaitem.01:11020>], 500, 480, 2000);
Adds recipe with only one input (Graphite dust -> Grtaphene dust)