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Method for recovering silicon material from waste materials in cutting crystalline silicon by diamond wire

A diamond wire cutting, silicon material technology, applied in chemical instruments and methods, silicon compounds, non-metallic elements, etc., can solve the problems of lack of reasonable waste silicon material recycling and treatment methods, increase production costs of enterprises, environmental damage, etc. The effect of low cost, easy operation and simple method

Inactive Publication Date: 2012-08-22
ZHENJIANG HUANTAI SILICON TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there is no reasonable recycling method for this type of waste silicon material, resulting in a waste of resources
The disposal of waste will increase the production cost of the enterprise, and if it is not handled properly, it will cause damage to the environment

Method used

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  • Method for recovering silicon material from waste materials in cutting crystalline silicon by diamond wire
  • Method for recovering silicon material from waste materials in cutting crystalline silicon by diamond wire

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Put the collected waste into a centrifuge for centrifugal sedimentation to obtain a silicon material precipitate. The precipitate is rinsed with pure water for 30 minutes at room temperature to remove organic matter in the residual liquid in the solid and obtain a certain purity of silicon powder. Then put the sorted solid-phase silicon powder into the hydrochloric acid aqueous solution with a concentration of 12%, soak for 2 hours while stirring to remove metal impurities, rinse with pure water, and then pass into an aqueous hydrofluoric acid solution with a concentration of 5%. In the process, soak the silicon material for 2 hours while stirring to remove the oxide on the surface of the silicon powder. Rinse and dry the reacted silicon material again. The rinsing method is ultrasonic rinsing in pure water at room temperature for 20 minutes, and the drying method is baking at 100°C for 3 hours, and the obtained silicon powder is directional solidified and cast into an i...

Embodiment 2

[0024] Put the collected waste into a centrifuge for centrifugal sedimentation to obtain a silicon material precipitate. The precipitate is rinsed with pure water and solid phase for 120 minutes at room temperature to remove the organic matter in the residual liquid in the solid and obtain a certain purity of silicon powder. Then put the sorted solid-phase silicon powder into the hydrochloric acid aqueous solution with a concentration of 17%, soak for 1.5 hours while stirring to remove metal impurities, rinse with pure water, and then pass through a 35% hydrofluoric acid aqueous solution During the process, soak the silicon material for 1.5 hours while stirring to remove the oxide on the surface of the silicon powder. Rinse and dry the reacted silicon material again. The rinsing method is ultrasonic rinsing in pure water at room temperature for 120 minutes, and the drying method is baking at 115°C for 2.5 hours. The obtained silicon powder is directional solidified and cast int...

Embodiment 3

[0026] Put the collected waste into a centrifuge for centrifugal sedimentation to obtain a silicon material precipitate. The precipitate is rinsed with pure water in solid phase for 240 minutes at room temperature to remove the organic matter in the residual liquid in the solid and obtain a certain purity of silicon powder. Then put the sorted solid-phase silicon powder into the hydrochloric acid aqueous solution with a concentration of 20%, soak for 1 hour while stirring, remove metal impurities, rinse with pure water, and then pass into a hydrofluoric acid aqueous solution with a concentration of 50%. In the process, soak and wash the silicon material for 1 hour while stirring to remove the oxide on the surface of the silicon powder. Rinse and dry the reacted silicon material again. The rinsing method is ultrasonic rinsing in pure water at room temperature for 240 minutes, and the drying method is baking at 130°C for 2 hours, and the obtained silicon powder is directional sol...

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PUM

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Abstract

The invention discloses a method for recovering silicon material from waste materials in cutting crystalline silicon by a diamond wire. The method is characterized by comprising the following steps of: feeding the collected waste materials to a centrifugal machine to centrifuge and settle, thus obtaining silicon material sediment; carrying out solid-phase rinsing on the silicon material sediment to remove organic matter type impurities and part of diamond powder from residual liquid in solid, thus obtaining silicon powder with certain purity; pickling the solid-phase silicon powder with hydrochloric acid to remove metal impurities; after rinsing the silicon powder subjected to hydrochloric acid pickling with pure water, rinsing the silicon powder with hydrofluoric acid to remove oxide from the surface of the silicon powder; carrying out ultrasonic rinsing and drying on the silicon material rinsed with hydrofluoric acid; carrying out directional solidification, ingot casting and purification on the dried silicon material, thus obtaining a solar grade silicon material; and at last, carrying out packaging after smashing, pickling, rinsing and drying the silicon material. The method is simple and convenient, the equipment cost is low, the operation is easy to control, the treatment recovery rate is high and the overall recovery rate can achieve over 99.99%.

Description

technical field [0001] The invention relates to a method for recovering silicon material and removing impurities, in particular to a method for recovering silicon material from waste produced by diamond wire cutting crystal silicon. Background technique [0002] Silicon wafers used for solar photovoltaic cells are straight-pulled from polycrystalline silicon raw materials into single crystal rods or cast into polycrystalline ingots. After removing the unqualified areas such as the head, tail and some shadows of the silicon ingots, they are cut into thin slices by a slicer made. The current slicing technology mainly includes steel wire carrying slurry cutting and diamond wire cutting technology. In the process of cutting with diamond wire, the silicon powder cut off enters the cooling water system of the slicer. The main component of these solid wastes is silicon powder, mixed with some metal impurities mainly nickel, trace diamond particles, Dust mud, organic impurities, e...

Claims

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Application Information

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IPC IPC(8): C01B33/037
Inventor 林慧袁志钟王禄宝
Owner ZHENJIANG HUANTAI SILICON TECH
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