Treatment of Silica top coat

A. Questions like this are best directed to the suppliers. But failing that, I'm happy to provide a little expertise. Silicated topcoats (sometimes called 'sealers' but IMHO topically applied inhibitors that function synergistically with chromates and chromate-generating passivates) will not be detrimental to your waste treatment system. Similar compounds and formulations have been used to chemically 'fix' or stabilize metal hydroxide wastes. They are quite effective in this regard, as nearly all silicates are less soluble than their hydroxide counterparts. Of course, this would be an expensive way to precipitate metals.