Silver recovery kit for spent fixer

Description

Precipitates dissolved silver out of spent fixer as a sludge you can collect and hand in. It solves two problems at once: the silver does not go down the drain and it does not go to waste.

Why spent fixer cannot be poured away

Used fixer accumulates silver compounds — a heavy metal toxic to aquatic life. Pouring it into household drains is prohibited in most countries, and not as a formality: silver does not break down and accumulates up the food chain.

What to do with the sludge

After precipitation the clear solution is decanted and the sludge dried. A litre of thoroughly used film fixer holds several grams of silver — with regular processing that adds up over a year.

Questions and answers

Can the sludge be melted down directly?

That is refining work. The sludge is collected and handed in — that is the form recyclers accept.