Cold Nitric recipe problem

[DaleCarr103]

I've been using this recipe for about a month and end up with kind of the same results as above. I us distilled water and LL as the Sulphuric acid. What I end up with is a pale yellow fluid with about 1/2 to 3/4 inch layer of salt cake on the bottom. it yields about 120-140 ml of apparently very weak Acid. I've even used it almost full strength on Silver and it barely has much effect. Does anyone know what the results should look like? Clear? The recipe says it yields 50%. I don't think I'm getting even close to that..

Any suggestions appreciated.

Dale