| abstract |
A diatomaceous earth product and methods of using the diatomaceous earth product are disclosed. The diatomaceous earth product may comprise sodium flux calcined diatomaceous earth, wherein the diatomaceous earth product has a crystalline silica content of less than about 1 wt%, and the diatomaceous earth product has a permeability of 0.8 darcy to about 30 darcy. In some embodiments, the diatomaceous earth product may be in granular or powder form. The invention also relates to a fluxed calcined silica product containing low or undetectable levels of crystalline silica. Some of these products can be further characterized by high permeability, measurable levels of opal-C, and hydrated forms of silica. |