Spray Granulation of Silica for High-Purity Quartz Glass
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Solution Overview
Problem
Current methods for producing quartz glass bodies face challenges in achieving high purity, homogeneity, and cost-effectiveness, leading to issues such as impurities causing defects, bubbles, and increased production costs, particularly in applications like semiconductor manufacturing and lighting where high-quality glass is required.
Innovation Solution
A method involving the production of silicon dioxide granules through spray drying a silica slurry using a nozzle with a glass contact surface, which results in larger particle diameter granules with improved purity and homogeneity, reducing contamination and the need for post-treatment processes like annealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to produce quartz glass bodies, then production cost is reduced, but purity and homogeneity deteriorate leading to impurities, bubbles, and defects
Solution Approach 1:
The patent applies preliminary action by granulating the silicon dioxide powder before melting to form quartz glass. The granulation process pre-treats the raw material by forming uniform granules with controlled pore structure, which eliminates the need for extensive post-treatment and annealing after melting. This preliminary preparation ensures high purity and homogeneity are achieved during the granulation stage itself, rather than requiring complex post-processing steps.
Solution Approach 2:
The patent utilizes parameter changes by controlling the pore volume of the granules within a specific range (0.1 to 2.5 mL/g) and adjusting the granulation process parameters. By optimizing these parameters during granulation, the process achieves both high purity/homogeneity and cost-effectiveness, as the controlled pore structure allows for complete melting without requiring expensive additional purification steps.
2Productivity
If byproducts are disposed of as waste or filler material, then handling and health risks are reduced, but resource efficiency deteriorates
Solution Approach 1:
The patent applies the discarding and recovering principle by taking silicon dioxide byproducts (fine dust) that would normally be disposed of as waste or used as low-value filler material, and recovering them through the granulation process. The fine dust is converted into valuable granules with controlled properties suitable for high-purity quartz glass production. This transforms a harmful waste stream into a useful raw material, simultaneously improving resource efficiency and eliminating health hazards associated with fine dust handling.
3Reliability
If irregularities and impurities are present in the glass body, then production cost is reduced, but reliability and quality deteriorate under stress and high temperatures
Solution Approach 1:
The patent applies preliminary action by performing granulation with controlled pore structure before the melting process. This pre-treatment ensures that the raw material is optimally prepared for melting, creating uniform granules that melt completely and homogeneously. The preliminary granulation step eliminates irregularities and prevents defect formation during melting, ensuring high reliability under stress and temperature without requiring complex quality control measures later in the process.
Solution Approach 2:
The patent utilizes parameter changes by controlling the pore volume parameter of the granules within a specific range (0.1 to 2.5 mL/g). By optimizing this key parameter during granulation, the process achieves complete melting and homogeneous glass formation, eliminating the need for complex post-processing and annealing steps while ensuring high reliability and quality of the final product under stress conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method produces quartz glass bodies with enhanced purity, reduced bubble formation, and improved thermal stability, enabling efficient and cost-effective production suitable for demanding applications like semiconductor manufacturing and lighting.
Implementation Method 1
spray-drying a silicon dioxide slurry using a nozzle
Data Source
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AI summary
The invention relates to a method for producing a silica glass article, involving method steps i.) providing a silica granulate, ii.) forming a glass melt from the silica granulate, and iii.) forming a silica glass article from at least some of the glass melt, step i.) comprising step I. providing a silica powder and step II. processing the powder to obtain a silica granulate, the processing involving spray drying a silica suspension using a nozzle. The nozzle has a contact surface to the suspension composed of glass, plastic or a combination thereof. The invention further relates to a silica glass article that can be obtained by said method. The invention also relates to the production of a silica granulate. The invention finally relates to an optical waveguide, an illuminant and a molded article, each of which can be obtained by further processing the silica glass article.