can you explain?
precipitating silver from what solution?
as far as I know caustic (sodium hydroxide) will precipitate most metals from acid but if too much many will dissolve in it. I see better methods for silver.
unless you are using caustic and aluminum to convert silver chloride,
you can use a chloride like table salt, or HCl to precipitate silver from silver nitrate solution, a pure copper bar works good also.