Acid-treated filter aid blend
A filter aid composition may include a first acid-treated silica-based filter aid having a first particle size distribution and a second acid-treated silica-based filter aid having a second particle size distribution. A method of making a filter aid composition may include providing a first silica-based filter aid having a first particle size distribution, providing a second silica-based filter aid having a second particle size distribution, and blending the first silica-based filter aid with the second silica-based filter aid to form the filter aid composition. A method of filtering a fluid may include providing a filter aid composition including a first acid-treated silica-based filter aid and a second acid-treated silica-based filter aid and filtering the fluid through the filter aid composition. The filter aid composition may have a multimodal particle size distribution such that the first particle size distribution has a d50 greater than the second particle size distribution.
1. A method of making a filter aid composition, the method comprising:
providing a first silica-based filter aid having a first particle size distribution;
providing a second silica-based filter aid having a second particle size distribution; and
blending the first silica-based filter aid with the second silica-based filter aid to form the filter aid composition,
wherein the filter aid composition has a multimodal particle size distribution such that the first particle size distribution has a d 50 greater than the second particle size distribution;
wherein the first silica-based filter aid has a d 50 in a range from about 10 μm to about 50 μm; and
wherein the second silica-based filter aid has a d 50 in a range from about 0.5 μm to about 15 μm.
2. The method of claim 1 , further comprising acid-treating the first silica-based filter aid composition prior blending with the second silica-based filter aid composition.
3. The method of claim 2 , wherein the acid is selected from the group consisting of oxalic acid and glacial acetic acid.
4. The method of claim 1 , further comprising acid-treating the second silica-based filter aid composition prior blending with the first silica-based filter aid composition.
5. The method of claim 1 , further comprising acid-treating the filter aid composition after blending the first silica-based filter aid with the second silica-based filter aid.
6. The method of claim 2 , wherein the acid-treated first silica-based filter aid has a soluble iron content less than or equal to about 20 ppm.
7. The method of claim 4 , wherein the acid-treated second silica-based filter aid has a soluble iron content less than or equal to about 20 ppm.
8. The method of claim 1 , wherein the filter aid composition has a permeability in a range from about 0.05 Darcies to about 0.2 Darcies.
9. The method of claim 1 , wherein the filter aid composition comprises from about 5 wt % to about 95 wt % of the first silica-based filter aid.