| Silicate clay minerals are important parts of mineral materials. Because of their unique physical and chemical properties, they have been widely used in aspects of industrial productions and daily life. Jiangxi Illite mineral resource is abundant, but it has the complex petrogenesis and its color is relatively dark which make it more difficult to put into application directly. In this paper, according to the particular physical properties of the illite, a series of processing technologies were designed to improve its industrial application value.In this paper, the mineralogy properties of Illite were scientifically characterized by laser particle size analyzer, XRD, FTIR, SEM and other methods. Based on the analysis results, the experimental approaches of desliming and bleaching, intercalation and delamination, surface modification were settled on. Finally, the ultrafine modified illite was prepared successfully and had been used as mineral powder filler to reinforce PE and PP. The experiment conclusions as follows:(1)、Except for Illite, Jiangxi Illite also contains kaolinite, montmorillonite and quartz. Ferric iron impurities which formed through rock weathering made that the Illite had the relatively low blu-ray whiteness and it was only 38.04%. The particle diameter sizes of illite ran from small to large, but mainly concentrated in 8.02 to 28.94 microns.(2)、The sodium silicate was used as desliming agent to remove the slime, when the addition amount of sodium silicate was 0.3%, the blu-ray whiteness of Illite increased 3.03%. The orthogonal experiment method was selected to bleach the Illite which had been removed slime. When slurry concentration was 25%, the concentration of HCl was 25%, reaction time was 120 min and temperature was 90℃, the best bleaching effect was achieved and the blu-ray whiteness of sample increased 9.28%.(3)、This paper chose N2H4·H2O as final intercalating agent to intercalate the interlayers of Illite. When the addition amount of N2H4·H2O was 30%, reaction time was 4h and temperature was 40℃, intercalated composites were obtained, and delaminated the composites to prepare relatively smaller particles. Compared with original Illite, D25, D50 and D90 of those smaller particles decreased 2.06μm, 3.57μm and 3.86μm, respectively and specific surface area of them increased 0.06m2/g. D50 was defined as the final evaluation criteria, the diameters of those smaller particles were less than 10 microns, so the ultrafine Illite was prepared successfully. XRD spectrum analysis showed that the N2H4·H2O molecules had entered the interlayers of Illite, which its d-spacing of the(002) and(006) crystal planes increased 0.13? and 0.01?, respectively. As the proton donors, N2H4·H2O molecules destroyed the hydrogen bonds between interlayers, and formed new hydrogen bonds with oxygen atoms in the silicon oxygen tetrahedrons, then accomplished the process of intercalation.(4)、KH-560 was chose as coupling agent to modify the surface of Illite. When the addition amount of KH-560 was 0.5%, reaction time was 120 min and temperature was 140℃, the oil absorption rate of modified Illite decreased 7.6% and its contact angle increased 23°. FTIR spectra analysis showed that modified illite samples had new absorption peaks at 2941cm-1 and 2884cm-1 which were ascribed to the stretching vibrations of-CH2. It suggested that KH-560 formed bonds with –OH from Illite surface and coated on surface of Illite, which improved its hydrophobicity.(5)、The ultrafine modified illite was used as filling agent to reinforce PE and PP. Compared with pure PE, when the addition amount of filler was 2%, mixing time was 15 min and temperature was 220 ℃,the tensile strength and elongation of the composites increased 53.00% and 37.28%, respectively; Compared with pure PP, when the addition amount of filler was 3%, mixing time was 10 min and temperature was 220℃,the tensile strength and elongation of the composites increased 20.48% and 48.09%, respectively. |
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