Study On The Mechanism And Characteristics Of Resistivity Of Muscovite And Their Surface Modified Products

Muscovite have a special crystal structure, its lattice is very stable, Minerals with the characteristic of high volume and surface resistivity, lower dielectric loss, arc resistant, corona resistance, high dielectric strength, thermal Expansion small, good in thermal shock resistance. Therefore, the prospects of insulating pouring sealant which use it as filler is very good. In order to further enhance the insulation properties of new type of muscovite insulation insulating pouring sealant, as well as, providing the scientific basis for development of Muscovite minerals. We system sudty on the Resistivity characteristics of microcrystal muscovite, muscovite, broken mica, muscovite mica and other minerals important producer of China, the resistivity characteristics, and mineral particle size and surface modification on its resistivity, and through silica, corundum Comparison of conventional mineral powder filler, and mineralogical characteristics of the test analysis, more in-depth study of the mechanism using PC68 digital impedance meter, self made small measuring electrode, WE-100 hydraulic universal testing machine, Riguka Dmax-ⅢC X-ray powder diffraction, Spetrum One type of Fourier transform infrared spectroscopy, STA409PC thermal analyzers and other equipment. The mechanism were also discussed test analysis of mineralogical characteristics.The Research results and progress achieved are as follows:(1) XRD analysis using modern analytical techniques and other minerals important producer of mica minerals in China's mineralogical characteristics, the results show that the experiment selected microcrystalline muscovite, muscovite, crushed mica, sericite and other important origin of Chinese white Parent minerals were formed by the 2M1 muscovite type, there is almost no other impurities in the mineral; Danba crystallization of muscovite and sericite Huangzhuang the highest, followed by Sichuan microcrystalline muscovite, mica crystallinity broken Lingshou minimum; in muscovite Crystal layer between the part of the K⁺ was Ca²⁺, Na⁺ substitution and octahedral there Fe³⁺, Fe²⁺, Mn²⁺, Mg²⁺, Ti4+ instead of Al³⁺, which went Sichuan microcrystalline muscovite and Hebei lingshou crushed mica octahedral Al by Fe and Mg exchange The most common (Ft (Ft = Fe + Mg) contents were 6.55% and 6.23%).(2) There has been no an effective method to measure resistivity of mineral powder and other powder materials until now. A formula to calculate resistivity of mineral powder by the testing data of its powder compacts was derived according to the compacts characteristics and the generalized effective medium equation (GEM). Taking micro-crystal muscovite for example, the experimental results proved that the measurement method is effective and feasible because the resistivity data of mineral powders are the same as that of their dense blocky samples. Further experimental results show that the volume resistivity and surface resistivity of mineral powder are not influenced by mineral particle size. And the upper and lower faces of powder compacts do not affect the volume resistivity of mineral powder, but affect the surface resistivity obviously. So, it is necessary to characterize the surface resistivity of mineral powder by the testing data of the upper face (punch face) of powder compacts. Moreover, the resistivity of mineral powder is greatly influenced by both the drying time and standing time in air. Therefore, in order to obtain correct result, the samples should be dried to constant weight before testing, isolated from air during cooling and measured immediately when exposed to air, as well as the testing time should be as short as possible.(3) system test and compare the important origin of Chinese minerals muscovite powder volume resistivity and surface resistivity, and mineral resources, according to mineralogical characteristics of these results show that: muscovite mineral content of impurities in crystals of muscovite Resistivity of minerals to a certain extent, the more crystal defects inside the carrier involved in conducting the more appropriate rate, the lower the resistance, but isomorphic minerals of muscovite did not affect the resistivity (About 1 order of magnitude or so), so the higher the crystal structure of Fe in the West with microcrystalline muscovite mica is broken and Hebei lingshou excellent performance of insulation materials. Contrast muscovite minerals and other traditional insulation pouring sealant packing a-alumina and silica found: muscovite minerals generally higher than the resistivity of a-alumina and silica high.(4) Taking 800 mesh muscovite ceramic powder for example, system testing and comparison of 1#, 2#, 3#, 4#, 5#coupling agent modified mineral powder resistivity results show that : After surface modification of ceramics after muscovite mineral powder over the unmodified microcrystalline muscovite powder 800 mesh (800 mesh is not modified microcrystalline muscovite powder volume resistivity and surface resistivity were 2.19×1012Ω? cm and 6.49×1010Ω), volume resistivity and surface resistance rates were increased by about 1 order of magnitude, further research results show that: in the placement of air time on the modified mineral powder resistivity than its Unmodified microcrystalline muscovite powder resistivity is not very obvious.