Method for recovering silicon powder from cut mortar waste
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A technology for cutting waste sand and silicon powder, which is applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve the problem that the purity of solar-grade silicon materials cannot be reached, and achieve the effect of simple process and controllable operation
Inactive Publication Date: 2014-12-03
佳明新材料科技有限公司
View PDF2 Cites 18 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
Chinese patent CN2010138035 discloses "Recycling and processing method of silicon wafer cutting waste mortar", in which the content of recycled silicon powder involved is only 90%, and its purity is far below the requirements of solar-grade silicon materials
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0015] The wire cutting waste mortar is composed (weight%): 45% of PEG, 6.5% of silicon powder, 46.6% of silicon carbide abrasive grains, 1.5% of metal, and 0.4% of unknown substances. Take 1 ton of waste cutting mortar.
[0016] (1) Solid-liquid separation process: first carry out solid-liquid separation of wire cutting waste mortar to obtain 542 kg of solid mixture, and the filtrate is circulated to the cutting fluid for recycling; carbon disulfide ethanol solution (2% by weight) is added to the solid mixture for stirring Dilute, wash to remove suspended impurities, filter, wash with ethanol, and filter again to obtain 535kg of mixed sand powder, and the washing liquid is collected and recycled for reuse;
[0017] (2) Magnetic separation and separation process: the obtained mixed sand powder is subjected to magnetic separation and separation to remove iron and iron oxides and iron-based metal impurities containing various alloying elements such as Cr, Ni, Ti, Mn, etc., to ob...
Embodiment 2
[0021] The wire cutting waste mortar is composed (weight%): 45% of PEG, 6.5% of silicon powder, 46.6% of silicon carbide abrasive grains, 1.5% of metal, and 0.4% of unknown substances. Take 1 ton of waste cutting mortar.
[0022] (1) Solid-liquid separation process: first carry out solid-liquid separation of wire cutting waste mortar to obtain 542 kg of solid mixture, and circulate the filtrate to the cutting fluid for recycling; add carbon disulfide ethanol solution (5% by weight) to the solid mixture and stir Dilute, wash to remove suspended impurities, filter, wash with ethanol, and filter again to obtain 534.6 kg of mixed sand powder, which is collected and recycled for reuse;
[0023] (2) Magnetic separation and separation process: the obtained mixed sand powder is subjected to magnetic separation and separation to remove iron and iron oxides and iron-based metal impurities containing various alloying elements such as Cr, Ni, Ti, Mn, etc., to obtain Mixture of silicon po...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
PUM
Property
Measurement
Unit
density
aaaaa
aaaaa
Login to view more
Abstract
The invention discloses a method for recovering silicon powder from cut mortar waste. According to the adopted technical scheme, the method comprises the following steps of: carrying out solid-liquid separation on the cut mortar waste to obtain a solid mixture, and adding an ethanol solution of carbon bisulfide to wash away suspended impurities to obtain mixed sand powder; carrying out magnetic separation on the obtained mixed sand powder to remove iron, iron oxides and metal impurities; carrying out acid cleaning; carrying out solution floatation and gravity separation to recover suspended matters, then washing the suspended matters by using ethanol, and drying to obtain high-purity silicon powder. The method disclosed by the invention effectively integrates the silicon powder recovery process through the steps of a solid-liquid separation procedure, a magnetic separation procedure, an acid cleaning procedure, a solution floatation procedure and the like, thus achieving the advantages of simple process, operation controllability, excellent economical performance and no secondary pollution. According to the method for recovering the silicon powder from the cut mortar waste, the recovery rate of silicon powder is higher than 80%, the content of silicon powder monomers is higher than 99%, and the silicon powder can be used as a raw material of a solar silicon wafer and is suitable for industrial popularization and application.
Description
Technical field: [0001] The invention relates to the field of solar silicon chip cutting, in particular to a method for recovering silicon powder from cutting waste mortar. Background technique: [0002] With the reshuffle of the solar silicon wafer cutting industry and the continuous decline in profits, silicon wafer cutting companies have invariably played the card of controlling the production process and reducing production costs. The most direct is the recycling of cutting fluid and silicon carbide micropowder among the three major auxiliary materials. [0003] Solar cells are generally produced by multi-wire sawing with mortar cutting. The mortar used in wire cutting is usually made of mineral oil or polyethylene glycol (PEG) and other media with a certain viscosity mixed with SiC abrasive powder; wire saw wire The diameter is generally 0.18mm, and the resulting kerf width is generally 0.2-0.3mm, while the thickness of the current solar cell silicon wafer is 0.18-0.22...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more