niks neims
Well-known member
Is there ever silver in this type of keypads:
https://en.wikipedia.org/wiki/Silicone_rubber_keypad
wikipedia lists carbon and it looks like carbon, but the reason why I am asking is that I stumbled upon this post while lurking ScrapMetalForum:
https://www.scrapmetalforum.com/general-electronics-recycling/7921-old-lcd-displays.html
(i hope it is not against the rules to post it here)
Sadly those photos seem to no longer be displaying but I will attach some of my own, from Mitel superset 4### series that look very similar. problem is - i tried to test (dissolve) those spots in nitric with absolutely no effect... are they carbon?
https://en.wikipedia.org/wiki/Silicone_rubber_keypad
wikipedia lists carbon and it looks like carbon, but the reason why I am asking is that I stumbled upon this post while lurking ScrapMetalForum:
https://www.scrapmetalforum.com/general-electronics-recycling/7921-old-lcd-displays.html
(i hope it is not against the rules to post it here)
On the third photo, of the keyboard, those big grey/black spots are silver.
Scrape em off & dissolve em in nitric acid till it turns blue & then precipitate the silver out with some copper
Sadly those photos seem to no longer be displaying but I will attach some of my own, from Mitel superset 4### series that look very similar. problem is - i tried to test (dissolve) those spots in nitric with absolutely no effect... are they carbon?