The invention discloses a preparation method of high-oil-absorption high-reinforcement
silicon dioxide for rubber products. The preparation method comprises the steps: firstly, accurately preparing water glass in a preparing tank; then, transferring
processing hot water into a reactor from a
warm water tank, transferring water glass into the reactor from a refining tank, heating the temperature to 60 DEG C; adding
sulfuric acid and dilute water into the reactor while carrying out stirring, controlling pH to 6.5 to 7.0, then, stopping stirring, and carrying out aging for 30 minutes; starting to carry out stirring, meanwhile, heating the temperature to 85 DEG C, and starting to carry out flow merging; firstly, adding flow-merged water glass until the pH value is 9 to 10, then, adding
sulfuric acid, and controlling the pH value to 9.5 to 10.5; carrying out stirring uninterruptedly after flow merging ends, adding the
sulfuric acid and the dilute water for post-acidification, and controlling the pH value to 4.8 to 5.3 at an end; carrying out aging and stirring for 20 minutes, and ending the reaction. The
silicon dioxide prepared by the preparation method has the characteristics of high specific surface area and high
oil absorption and is low in
loss on ignition and high in pH value, so that the
vulcanization time of the rubber products is shortened by 50% or more, and the
processing efficiency is greatly increased.