Biodegradable Polymer Sacrificial Support for Silicon Recycling
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Solution Overview
Problem
The silicon powder produced during the abrasive wire cutting process for photovoltaic cells is contaminated with metallic and light elements like carbon and oxygen, making it difficult to recycle and resulting in significant material loss, as conventional cutting supports and lubricants contribute to contamination, which is hard to remove and impractical to manage in industrial settings.
Innovation Solution
A sacrificial support made of a biodegradable polymer material soluble in a solvent is used during the cutting process, which reduces contamination and allows easy recycling of the silicon powder by dissolving the support, thereby minimizing contamination and facilitating the recovery of high-purity silicon powder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cutting supports made of polymer resin filled with alumina particles are used, then the cutting process is supported, but the silicon powder becomes contaminated with metallic elements and light elements that are difficult to remove
Solution Approach 1:
The invention extracts and removes the harmful contamination sources (alumina particles and polymer resin) from the cutting support system. By using a sacrificial support made of sugar or starch, these harmful elements are completely eliminated from the cutting process, allowing the silicon powder to be recovered with high purity without the need for complex filtration systems.
Solution Approach 2:
The invention employs a disposable sacrificial support made of biodegradable materials (sugar or starch) that is intentionally designed to be consumed during the cutting process. This support is then easily removed and replaced, eliminating the need for expensive and complex filtration systems while ensuring high purity silicon powder recovery.
2Productivity
If filtration and centrifugation systems are used to recover silicon powder, then the powder can be recycled, but the contamination from metallic elements and light elements remains prohibitive for future crystallization
Solution Approach 1:
The invention extracts the contamination sources at the source by using a sacrificial support that does not introduce metallic or carbonaceous impurities. This eliminates the need for complex filtration and centrifugation systems, allowing direct recovery of high-purity silicon powder suitable for recrystallization.
Solution Approach 2:
By using a disposable sugar or starch support, the invention avoids the need for expensive filtration and centrifugation equipment. The sacrificial support is intentionally designed to be consumed and easily removed, enabling simple and effective silicon powder recovery with high purity without complex separation systems.
3Object-generated harmful factors
If a sacrificial support made of biodegradable polymer material soluble in a solvent is used, then contamination is reduced and recycling is facilitated, but the support must be dissolved and separated from the silicon powder
Solution Approach 1:
The invention changes the physical-chemical parameters of the support material by using sugar or starch, which are soluble in water. This solubility parameter allows the support to be easily removed from the silicon powder mixture through simple water washing, eliminating the need for complex filtration or centrifugation systems while maintaining high purity.
Solution Approach 2:
The disposable sugar or starch support is designed to be completely consumed and easily removed through simple water washing. This approach eliminates the need for complex filtration and centrifugation equipment, reducing process complexity while ensuring high purity silicon powder recovery suitable for recrystallization.
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
The process significantly reduces contamination, allows for easy recycling of silicon powder, and produces high-purity silicon with low carbon and oxygen content, enabling the reuse of the powder for new ingots without the formation of impurities like silicon carbide and oxide.
Implementation Method 1
a sacrificial support made of a biodegradable polymer material soluble in a solvent is used during the cutting process, which reduces contamination and allows easy recycling of the silicon powder by dissolving the support
Implementation Method 2
separating the solid phase from the liquid phase, in particular by a centrifugation or filtration step
Implementation Method 3
separating the solid phase from the liquid phase, in particular by a centrifugation or filtration step
Data Source
Figure 1A~2
Figure 3A~4
Figure 5A~5C
AI summary
This sacrificial support (10) for cutting out a part, preferably of silicon, with abrasive wire is made of a biodegradable polymer material (11) which is soluble in a solvent. The process for cutting out a part with abrasive wire employing such a sacrificial support (10) produces a mixture comprising first particles obtained from the part to be cut out and second particles of biodegradable polymer material. The biodegradable polymer material is readily removable from this mixture, by dissolution, and the first particles can be recycled.