Silica Dilution

Try an acid bath.

Hire a mound of termites?

Hydrofluoric acid will dissolve silica.....

It dissolves practically everything else too....

Ozzb has it all laid out for you, the other answers are totally wrong - one never uses acid as a primary step in pulping (presuming you want cellulose fibers and starch yield). Always attack the silica (ash) with caustic potash/caustic soda, as this results in better silica removal from the plant substrate. Then, depending on what it is you are actually attempting to do, you might wish to use an acid such as sulfuric acid for hydrolysis if that is required. Hydrofluoric acid is a completely bad idea in every single instance except for etching/cleaning glass in a fabrication setting, and extreme care must be exercised to prevent poisoning the operators in the local shop.

Sometimes in the past hydrofluoric acid was used for metal cleaning where silicates had deposited, but this too is extremely dangerous to attempt, and has resulted in health problems for workers exposed when the slightest leakage occurs through PPE (cartridge masks, supplied air masks, etc.). Also, HF will absorb through skin, and will kill those exposed to sufficient accumulative dosage.

http://books.google.com/books?id=p5EUAAAAYAAJ&pg=PA86&lpg=PA86&dq=hydrofluoric+acid+used+in+pulping+straw&source=bl&ots=v0IQeC5KRR&sig=kNhV7Ol5OE5hSBFYvizk4KSScbk&hl=en&sa=X&ei=zj2FUt15w-zbBauTgOAL&ved=0CD4Q6AEwBDgK#v=onepage&q=hydrofluoric%20acid%20used%20in%20pulping%20straw&f=false

To ozzb

Thank you for your direction. Your information will assist leverage in selected direction.

Thank you John Gorman