Method for purifying semiconductor-grade quartz sand without acid
The purification system, which combines acid-free complexation scrubbing, neutral reverse flotation, and gradient chlorination roasting, solves the problems of equipment corrosion and environmental pollution in existing quartz sand purification processes, achieving efficient quartz sand purification and obtaining high-purity semiconductor-grade quartz sand.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KAISEN QUARTZ MATERIALS (TAIHU) CO LTD
- Filing Date
- 2026-04-07
- Publication Date
- 2026-07-17
AI Technical Summary
Existing quartz sand purification processes rely on volatile acids and fluorine-containing inhibitors, leading to equipment corrosion, environmental pollution, and occupational health risks, and cannot meet the high purity requirements of semiconductor-grade quartz sand.
A purification system consisting of acid-free complexing scrubbing, neutral reverse flotation, and gradient chlorination roasting is employed. The complexing scrubbing agent, a mixture of aminotrimethylene phosphonic acid and hydroxyethylidene diphosphonic acid, is used to remove metallic impurities under alkaline conditions. The neutral flotation system achieves efficient separation of quartz and gangue through hydroxypropyl oxidized starch and a composite amphoteric collector. Gradient chlorination roasting removes impurities.
Efficient separation of quartz and gangue was achieved under neutral conditions, and metallic impurities in quartz were deeply removed, resulting in semiconductor-grade quartz sand with a purity of 99.9992%. This solved the problems of equipment corrosion and environmental pollution, and met the requirements of semiconductor-grade applications.
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