Abstract: A method for producing porous amorphous biogenic silica from siliceous plant matter through a three-element control architecture. Removal of non-siliceous inorganic flux constituents is maintained as a safety constraint preventing flux-induced sintering, crystallization, and pore collapse. Calcination temperature serves as the primary control variable, determining temperature-history-dependent surface-area plateaus in the range of 200-500 m2/g based on the complete thermal profile including ramp rate, peak temperature, and hold time.

Abstract: Porous amorphous silica can be obtained from siliceous plant matter containing non-siliceous inorganic substances. The siliceous plant matter is soaked in an aqueous solution which includes a chelating agent. The chelating agent is present in an amount which helps to extract at least some of the non-siliceous inorganic matter. The aqueous solution is then separated from the siliceous plant matter. Beneficial properties are imparted to the siliceous plant matter by controlling the amount of at least one preselected non-siliceous inorganic substance in the siliceous plant matter. At the end of the process, the siliceous plant matter is heat treated in the presence of oxygen at a temperature to produce the resulting amorphous silica having the beneficial properties.