Method for manufacturing zinc oxide nonlinear resistance slice used for lightning arrester

Abstract

The invention discloses a method for preparing a praseodymium series zinc oxide curve resistance, comprising the following procedures: additives are added according to the mol percentage: Co2O3is from 0.9 to 1.1 percent; Cr2O3 is from 0.4 to 0.6 percent; Pr6O11 is from 0.5 to 1.0mol percent; K2CO3 is from 0.5 to 1.0mol percent; Al(NO3)3.9H2O is from 0.025 to 0.032 percent; the remainder is the main ingredient of zinc oxide which is matched with ingredients and calculated and weighted, the additives are mixed to be calcined and then mixed with the zinc oxide to be comminuted by the wet method; the whole is kept at the temperature of 1200 to 1250 degrees for three to four hours to calcine a ceramic water after spray pelleting and moulding as well as binder removal, the ceramic water is cleaned and dried after polished dressing; finally, the two end surfaces of the ceramic water are sprayed with aluminium electrodes, the circle surface of the ceramic water is applied with an insulating barrier, and a resistance card is manufactured. The invention has a small variety of additives, is capable of increasing the effective area of grain boundary layer and increasing the discharge current capability, which contributes to improving the potential gradient of products and decreasing the leakage current; in addition, the addition of Al(NO3)3.9H2O introduces an aluminium ion and zinc ion to form a substitution type flaw, increases the thickness of conductive ions, decreases grain of zinc oxide, and obviously improves the residual voltage ratio of the praseodymium series zinc oxide curve resistance.

Description

technical field [0001] The invention relates to a preparation method of a non-linear resistance, in particular to a preparation method of a zinc oxide non-linear resistance sheet for a lightning arrester. Background technique [0002] Zinc oxide nonlinear resistors for lightning arresters, from the perspective of the main components of the formula, mostly use zinc oxide (ZnO) to add bismuth oxide (Bi 2 o 3 ), antimony oxide (Sb 2 o 3 ), manganese oxide (MnO 2 ), chromium oxide (Cr 2 o 3 ), cobalt oxide (Co 2 o 3 ) and other metal oxides (referred to as bismuth-based, the same below), the performance of bismuth-based zinc oxide nonlinear resistors can meet the requirements of product design to a certain extent, but because bismuth-based zinc oxide nonlinear resistors are fired Bismuth oxide (Bi 2 o 3 ) and the violent self-reaction above 1000°C are insufficient in terms of microstructure and electrical properties. The former causes the ratio of additives to appear u...

AI Technical Summary

Problems solved by technology

[0002] Zinc oxide nonlinear resistors for lightning arresters, from the perspective of the main components of the formula, mostly use zinc oxide (ZnO) to add bismuth oxide (Bi 2 o 3 ), antimony oxide (Sb 2 o 3 ), manganese oxide (MnO 2 ), chromium oxide (Cr 2 o 3 ), cobalt oxide (Co 2 o 3 ) and other metal oxides (referred to as bismuth-based, the same below), the performance of bismuth-based zinc oxide nonlinear resistors can meet the requirements of product design to a certain extent, but because bismuth-based zinc oxide nonlinear resistors are fired Bismuth oxide (Bi 2 o 3 ) and the violent self-reaction above 1000°C are insufficient in terms of microstructure and electrical properties. The former causes the ratio of additives to appear uneven inside the resistor sheet. The volatilization of substances (such as cobalt oxide, etc.) is suppressed to a certain extent, but its influence cannot be eliminated fundamentally. The latter destroys the micro-resistance structure that constitutes the overall resistor. The microstructure of bismuth-based resistors is generally formed by oxidation. It is composed of zinc grains, grain boundary layer and spinel of some zinc antimony oxides. The spinel phase can effectively inhibit the growth of zinc oxide grains during the firing process. It is an insulator in terms of electrical properties. Improving the performance is not helpful. To obtain excellent performance of the bismuth-based zinc oxide non-linear resistance medium, it is necessary to add more types of additives, which will inevitably increase the complexity and instability of doping control.

Praseodymium ZnO nonlinear resistors were mainly used for the protection of low-voltage systems in the early days. In recent years, with the deepening of knowledge and research on praseodymium systems, more and more attention has been paid to the research and development of applications in medium and high voltage systems. Early praseodymium Zinc oxide non-linear resistors mainly meet the protection requirements of low-voltage systems. Usually, Cr and K ions are introduced to improve the non-linear performance in the high-current region. The non-linear performance in the small-current region is better, and the high-current region is relatively poor. It is used in metal oxide arresters in medium and high voltage systems, and its residual voltage ratio performance cannot meet the requirements