It is always interesting to see the same questions being asked at regular intervals, one which still surprises me is the removal of base metals using acids.
It is as if the use of alkalis has never been considered.
Lead, tin and zinc are all soluble in caustic solution the usual caustic working level is around 20%, heat enhances the reaction.
If someone is wanting to use one of these as a collector metal, with caustic leaching you have the option of using whichever suits your purpose best rather than worrying over how to acid leach the metal away after use.
If you are just wanting to dissolve tin from scrap this presents a simple method, a rinse after leaching gets you material ready for precious metal leaching.
You can easily electrowin the base metals back from the caustic liquor if this is a viable method for you.
Deano