Preparation method of large quartz ceramic crucible

Abstract

The invention discloses a preparation method of a large quartz ceramic crucible, which is formed based on the method of gel casting molding, and particularly comprises the following steps: a) taking fused quartz with purity of 99.0-99.9% according to the mass percent as a raw material, and carrying out granular grading on the grains of the fused quartz; b) uniformly mixing the raw material proportioned by the step a), adding gel solution, preparing into pulp in a ball mill or a blender; c) injecting or pressure-injecting the prepared pulp prepared by the step b) into a preheated metal mold, and taking out from the metal mold after the pulp is solidified into green bodies; d) naturally drying the green bodies; and e) putting the dried green bodies into a high-temperature furnace, baking toobtian the large quartz ceramic crucible. Raw material grain proportioning and the preparation method, optimized by the invention, can product the quartz ceramic crucible with larger overall dimension and thin wall for fusion of special glass, casting of polycrystalline and calcining of rear earth material.

Description

technical field [0001] The invention relates to the technical field of quartz ceramic products, in particular to a method for preparing a large-scale quartz ceramic crucible. Background technique [0002] Quartz glass ceramics are referred to as quartz ceramics for short. Due to the small thermal expansion coefficient of quartz ceramics, their thermal expansion coefficient is only 0.54×10 -6 / °C, which makes it have very good resistance to rapid cooling and rapid heating; the thermal conductivity of fused silica ceramics is particularly low, and its thermal conductivity is only 2.1W / m K, so it is an ideal heat insulating material; quartz ceramics have excellent In addition to hydrofluoric acid and hot concentrated sulfuric acid, quartz ceramics have almost no effect on other acid substances and various metal melts, and have very good corrosion resistance to various glass slags. sex. Therefore, ceramic crucibles made of quartz glass, that is, quartz ceramic crucibles, are w...

AI Technical Summary

Problems solved by technology

However, the quartz ceramic crucible used for special glass and polysilicon melting requires relatively large dimensions, usually the maximum diameter is between 500-1100mm, and requires a relatively thin wall thickness, generally 10-20mm, so the production is relatively difficult

[0003] Regarding the crucible molding method, at present, plaster mold grouting method is mostly used at home and abroad to form large crucibles. The main disadvantages are: 1) It is impossible to add raw materials with larger particle sizes, which affects the reasonable particle gradation of raw materials; 2) Usually ball mills or agitators are used. Grinding and beating not only takes a long time for beating, but also consumes a lot of energy, and it is easy to grind the grinding body into the raw material; 3) Daily production needs to process a large number of plaster molds, which is labor-intensive and time-consuming; 4) The density of the formed green body is not uniform , especially when double-sided slurry suction is used, interlayers will be generated inside the green body