Precipitating Platinum ammonium chloride from Aqua Regia Solution.

The source of the Platinum was 16.7 grams of 90/10 Pt/Ir thermocouples. The alloy took 7 hours to completely dissolve in hot diluted AR. I used zinc to precipitate the Pt and Ir together, then treated the resulting black powder with diluted AR again. After the two additional AR digestions, 1.2 grams of black powder remained. I filtered the solution then denoxxed the resulting solution and filmed the video.

The Pt salt still has a scarlet tint indicating it still has some Ir in the salt. I'll have to calcine the salt and redissolve the resulting sponge in diluted AR, then precipitate again with ammonium chloride to get the nice canary yellow salt I'm looking for.