Decarboxylation
Pyrolysis
https://en.nncup.org/2607-ash-as-a-fertilizer-benefits-composition-use-in-the-g.html
https://en.m.wikipedia.org/wiki/Decarboxylation
https://en.m.wikipedia.org/wiki/Carbonylation
https://en.m.wikipedia.org/wiki/Pyrolysis
..
i suspect the pyrolysis process will lock zinc into the nitrogen & sulfur with ionic bonds, leaving the larger particles & heavy metals behind, along with charcoal.
https://en.m.wikipedia.org/wiki/Gasotransmitter
https://en.m.wikipedia.org/wiki/Disulfide
https://en.m.wikipedia.org/wiki/Oxidative_folding
https://en.m.wikipedia.org/wiki/Redox