sounds like you are removing gold with the concentrated sulfuric acid and electrolisis, and your asking how much sulfuric acid to use , as I havent used this method can I can only guess amount would not matter but would only strip what portion of your (GOLD)anode was in solution. not sure why you are adding SMB sodium metabisulfite is used to drop gold from chloride solutions, the concentrated sulfuric shouldn't disolve gold . the washed brown mud can be turned back to yellow gold, usually after re refining. not sure if I am any help, I suggest you study a process you plan to try untill you are confident you can get your gold and you understand it, the education will be much more valuble than a lil yellow metal,and can lead to getting more of that yellow metal, and nott loosing your gold. good luck Rodshanz