Research on the wet physical purification process of diatomite

To face the challenge of the superior diatomite resources getting rare,we proposed a wet physical separation process,by which the resourceful clayey diatomite of a middle or low grade was purified to a high grade.The chemical constituent,mineral composition and particle-size distribution of the raw diatomite were analyzed.The co-relation of the surface potential of the diatomite and montmorillonite with pH value and dispersant dosage was investigated.The optimal condition to scrub and disperse the diatomite slurry was determined.The raw diatomite slurry was completely dispersed according to the size and surface potential difference between the diatomite and the clayey minerals.The efficient separation was thus obtained in the centrifugal force field to enhance the sedimentation velocity difference between the diatom and the clay mineral particles.The actual production results show that the diatomaceous concentrate has reached the first grade standard of diatomite through the separation process with the change of SiO₂ content from 81.78% to 86.86%,Al₂O₃ content from 5.49% to 3.45% and Fe₂O₃ content from 2.01% to 1.42%.