50 results about "Hydrochloric acid regeneration" patented technology

The invention discloses a preparation method of ludox for an acrylonitrile catalyst. The method comprises: adding sulfuric acid aqueous solution into industrial sodium silicate aqueous solution with a silicon dioxide content of 3-5 wt percent until pH is 9.0-9.5, heating up to 90-95 DEG C, and then keeping warm for 1-2 hours to form ludox base solution; adding water into industrial sodium silicate with a modulus of 3.0-3.3, preparing aqueous solution with a silicon dioxide content of 3-5 wt percent, suspending cation exchange resin by using deionized water, then adding sodium silicate and controlling outlet pH to be 2-3 after ion exchange to obtain silicic acid, adding the silicic acid into the prepared ludox base solution at a speed of 100-200ml / min, keeping pH to be 9-9.5, keeping warm for 1-2 hours under the temperature of 90-95 DEG C, and then cooling to normal temperature; performing ion exchange on a product by using strong-acidity cation exchange resin regenerated by hydrochloric acid, meanwhile keeping pH to be 1-2, and after exchange, adding ammonium hydroxide and adjusting pH to be 9-9.5; finally adding a dispersing agent into the prepared ludox, and performing ultrafiltration and concentration to obtain the ludox. The prepared ludox has the mean grain size of 20-25nm, the sodium ion content less than 0.05 percent, the concentration of 40-50 percent and the viscosity less than 20cps.