Control method for firing high-performance quartz ceramic

Abstract

The invention provides a control method for firing high-performance quartz ceramic, which comprises the following steps: selecting high-purity (higher than 99.00%) quartz sand with reasonable grain size distribution, adding water, carrying out ball milling, homogenizing, adding the other two raw materials, carrying out secondary grain size distribution, stirring to injecting dynamic slurry into a mold, curing, and firing in a batch type kiln or progressive kiln through a six-step method, including low temperature stage, oxidative decomposition and crystal form transition stage, re-oxidative decomposition and firing stage, high temperature holding stage, cooling stage and recooling stage, thereby obtaining the high-performance quartz ceramic. The firing method provided by the invention saves the energy, promotes the development and utilization of high-performance quartz ceramic raw materials and natural gas, and effectively controls the firing temperature curve of the high-performance quartz ceramic; and the fired quartz ceramic has the advantages of uniform internal structure, excellent thermal shock stability and excellent rupture resistance. The operating process is stable, and implements low-carbon low-pollution emissions.

Description

technical field [0001] The invention relates to a high-performance quartz ceramic, in particular to a process method for controlling firing of the quartz ceramic in a batch kiln or a continuous kiln, and belongs to the field of new material preparation. Background technique [0002] In today's world, the crisis of conventional energy supply shortage is becoming more and more serious, and environmental problems are intensifying. As an emerging energy, solar energy has the advantages of non-pollution, sustainability, large amount, wide distribution, and various application forms. The utilization rate of this emerging energy in countries around the world and low-carbon environmental protection competition is extremely fierce. High-performance quartz ceramics are also high-temperature-resistant containers for polysilicon ingots, and are irreplaceable key consumable materials in the production process of solar polysilicon. In the preparation process of high-performance quartz ce...

AI Technical Summary

Problems solved by technology

The traditional firing process of high-performance quartz ceramics is prone to cracks due to temperature differences. The extension of micro-cracks is avoided by increasing the holding time, but the longer the holding time is, the higher the energy consumption is. Performance Quartz Ceramic Strength Decreased

[0004] The firing atmosphere of high-performance quartz ceramics includes oxidizing atmosphere, reducing atmosphere and neutral atmosphere. The crystallization ability of high-performance quartz ceramics is also different under different firing atmospheres. Due to the limitations of the current control system, the high-performance quartz ceramics The firing atmosphere is all fired in an oxidizing atmosphere. The oxidizing gas is easy to combine with the surface of the powder particles, and a higher concentration of oxidizing gas can promote its penetration and diffusion into the internal network structure of quartz, so as to achieve the formation of cristobalite. Necessary Si / O stoichiometric ratio, and then crystallization grows to form cristobalite, which reduces the strength of the sintered high-performance quartz ceramics, sharply increases the thermal expansion coefficient, and deteriorates the mechanical properties and thermal shock resistance

[0005] The firing of high-performance quartz ceramics is affected by the particle gradation of the quartz ceramic green body. The particle size distribution of the quartz ceramic green body is unreasonable. It is difficult to achieve a compact structure during the firing process of the quartz ceramic green body, which is manifested by a decrease in density and strength.

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