Crush 50 g of silver iodide to a fine powder, then combine 30 mL of nitric acid with 90 mL of hydrochloric acid. Then slowly start to add the silver iodide to the aqua regia with stirring, leave to stir for an hour. Then add 70 mL of cold water, then filter and wash twice with 100 mL of cold water. Collect the silver chloride. Then add 250 mL of very cold water to the filtered solution and put the mixture into a freezer for 2h then filter and wash with 100 mL of cold water. Collect the filtered iodine. Then add 20 g of sodium hydroxide to the iodine solution and left to crystallize overnight in a fridge, filter and collect the iodine. Pour the silver chloride into 250 mL of 15% ammonia solution with stirring, stir for 10 minutes and filter, the insoluble matter is silver iodide. Then start adding sodium dithionite solution with stirring until no more silver precipitates. Filter and wash with 200 mL of water and 50 mL of ethanol, dry the silver metal.
Sodium iodide reacting with the aqua regia
Stirring for one hour
Filtering the mixture and washing the precipitated silver chloride
After addition of the cold water and cooling, the mixture was filtered and the iodine was collected
Sodium hydroxide was added and the mixture was in fridge for 2h then the mixture was filtered and iodine was collected
All of the collected iodine
The silver ammonia complex solution
Sodium dithionite was added and the mixture was stirred for 10 minutes then filtered and washed.
Pure silver metal powder