Consider the following reaction: 3Si3N4 + 27H2O + 4H3PO4 --> 4(NH4)3PO4 + 9H2SiO3 --> ^4NH3(g) + 4H3PO4 + 9H2SiO3 --> 4H3PO4 + ?? The phosphoric acid solution is 85%wt. In your fella's opinion, what happens to the Meta Silicic Acid (H2SiO3)? Is the solution to acidic to form a polysilicic acid? Will this occur: H2SiO3 --> H2O + SiO2 and form a gelatinous poly silica? Something else? I do know that at relatively low concentrations of this silicate based product (~100PPM @ 155C) the product will come out of solution. Appreciate your thoughts, thanks guys.