Noxx
Well-known member
Hello,
I'm currently developping a simple process to make pure silver nitrate (or metal if you prefer) from Sterling silver. This should yield a product a least 99,9% pure. I'm not the inventor of the process in any ways, it's just ideas I gathered from ScienceMadness.org. Special thanks to Fleaker who helped me indirectly lol. If you think there are any flaws in my process, please let me know ! Any comments is also welcomed.
Cementation of silver with copper is a well know technique to produce silver metal of an acceptable purity, but you will always get some impurities from the Copper.
Method for producing 500 grams of photo grade AgNO3
-Start with incinerating you scrap silver to remove any dirt and oil residues. Do not melt the silver. More informations are available on this forum on how to do it properly.
-Let it cool then add your sterling (343,25 grams in this case) in a large beaker. 2000mL should suffice.
Following steps must be performed in a low light environnement.
-Add at least 1100mL of 30% nitric acid. When the reaction has stopped, add small amounts of HNO3 to dissolve the remaining pieces. Try not to add too much acid.
-Vacuum filter your solution to remove any insoluble particles. Use a fast to medium speed filter paper.
-Add NaCl (lab grade, food grade or equivalent) until no more precipitate forms. You now made Silver Chloride (AgCl) and Lead Chloride if there was any present.
-Decant your solution, you only want to keep the precipitate. Rinse the powder once in tap water.
-Then add enough HCl to cover it. Digest the powder in boiling HCl for one hour. This will dissolve any remaining metals. Use a magnetic stirrer if you have one. Keep your beaker covered with a watch glass. Decant the solution and rinse the powder two times with tap water. Not sure if this step is useful or not.
-Rinse you powder two times with boiling distilled water.
-Now dissolve your powder in Ammonium Hydroxide (lab grade, try not to use too much). Ammonia water will form a complex with silver but will not dissolve any lead chloride that may have still been present.
-Vacuum filter your solution using a medium to slow filter paper. Discart any precipitate.
-Add HCl to neutralize the ammonia and destroy the complex. This will form new AgCl. The amount of HCl used is not critical. Better too much than not enough. Add HCl until pH becomes acidic (under 7).
-Decant the solution and rinse your powder two times with tap water and two times with distilled water. This will remove the NH4Cl that formed during the neutralization.
-You can convert your Silver Chloride to Silver Oxide by the addition of an alkali solution like NaOH or KOH. Both are soluble in water in all proportions.
-Rinse your powder again with water a few times and heat to 300°C (590°F) to decompose your Oxide back to silver metal.
-At this time, your silver powder should be very pure, with only traces of other metals. You can either melt it to cast ingots or dissolve it back in Nitric acid (lab grade or higher) to make silver nitrate.
That's it !
Any comments ?
I'm currently developping a simple process to make pure silver nitrate (or metal if you prefer) from Sterling silver. This should yield a product a least 99,9% pure. I'm not the inventor of the process in any ways, it's just ideas I gathered from ScienceMadness.org. Special thanks to Fleaker who helped me indirectly lol. If you think there are any flaws in my process, please let me know ! Any comments is also welcomed.
Cementation of silver with copper is a well know technique to produce silver metal of an acceptable purity, but you will always get some impurities from the Copper.
Method for producing 500 grams of photo grade AgNO3
-Start with incinerating you scrap silver to remove any dirt and oil residues. Do not melt the silver. More informations are available on this forum on how to do it properly.
-Let it cool then add your sterling (343,25 grams in this case) in a large beaker. 2000mL should suffice.
Following steps must be performed in a low light environnement.
-Add at least 1100mL of 30% nitric acid. When the reaction has stopped, add small amounts of HNO3 to dissolve the remaining pieces. Try not to add too much acid.
-Vacuum filter your solution to remove any insoluble particles. Use a fast to medium speed filter paper.
-Add NaCl (lab grade, food grade or equivalent) until no more precipitate forms. You now made Silver Chloride (AgCl) and Lead Chloride if there was any present.
-Decant your solution, you only want to keep the precipitate. Rinse the powder once in tap water.
-Then add enough HCl to cover it. Digest the powder in boiling HCl for one hour. This will dissolve any remaining metals. Use a magnetic stirrer if you have one. Keep your beaker covered with a watch glass. Decant the solution and rinse the powder two times with tap water. Not sure if this step is useful or not.
-Rinse you powder two times with boiling distilled water.
-Now dissolve your powder in Ammonium Hydroxide (lab grade, try not to use too much). Ammonia water will form a complex with silver but will not dissolve any lead chloride that may have still been present.
-Vacuum filter your solution using a medium to slow filter paper. Discart any precipitate.
-Add HCl to neutralize the ammonia and destroy the complex. This will form new AgCl. The amount of HCl used is not critical. Better too much than not enough. Add HCl until pH becomes acidic (under 7).
-Decant the solution and rinse your powder two times with tap water and two times with distilled water. This will remove the NH4Cl that formed during the neutralization.
-You can convert your Silver Chloride to Silver Oxide by the addition of an alkali solution like NaOH or KOH. Both are soluble in water in all proportions.
-Rinse your powder again with water a few times and heat to 300°C (590°F) to decompose your Oxide back to silver metal.
-At this time, your silver powder should be very pure, with only traces of other metals. You can either melt it to cast ingots or dissolve it back in Nitric acid (lab grade or higher) to make silver nitrate.
That's it !
Any comments ?