Color-changing ph-indicating silica gel and preparation method thereof

A preparation method of a color-changing pH-indicating silica gel, comprising the following steps:

• S1, adding an acidic additive to silica gel particles for soaking, and keeping a PH of the silica gel particles at 3 to 7;
• S2, collecting wet silica gel particles produced after a treatment in the S1, dewatering and drying, and grading and screening dried silica gel particles according to a particle size of 0.5 mm to 2 mm to produce a silica gel raw material for dyeing;
• S3, adding a PH-indicating dye solution to the silica gel raw material, and thoroughly mixing, such that the PH-indicating dye solution evenly enters pores of the silica gel raw material and is adsorbed by the silica gel raw material to produce dyed silica gel particles with a moisture content kept at 15% to 50%, wherein the dyed silica gel particles are color-changing indicating silica gel particles;
• and
• S4, thoroughly mixing the color-changing indicating silica gel particles and an untreated raw material silica gel with a low moisture content.