Preparation method of modified diatomite compounded magnetic flocculant

The invention discloses a preparation method of a modified diatomite compounded magnetic flocculant, which comprises the following steps: step 1, mixing and stirring diatomite screened by a screen and magnetic powder according to a ratio of (1-5): 1 to obtain an original silica mixture; step 2, mixing the original silica mixture obtained in the step 1 with concentrated hydrochloric acid according to a ratio of (4-8): 1, slowly adding hydrochloric acid while adding, continuously stirring the mixture while adding, and stirring and reacting for 15-30 minutes to obtain an acid modified diatomite mixture; step 3, fully mixing and stirring the acid-modified diatomite mixture obtained in the step 2, PAC and magnetic powder according to a ratio of 1: 1: 1 to obtain a semi-finished product of the modified diatomite compound magnetic flocculant; and step 4, grinding, drying and screening the semi-finished product to obtain the modified diatomite compound type electrodeless magnetic flocculant. 本发明公开了一种改性硅藻土复配型磁性絮凝剂的制备方