Method used for processing silicon liquid

Abstract

The invention provides a method used for processing a silicon liquid. The silicon liquid contains aluminium, calcium, phosphor, and boron. The method comprises following steps: (1) the silicon liquid is oxidized with oxygen, a refining agent and a slagging constituent are added into the silicon liquid so as to obtain a solid oxidized slag containing aluminium oxide, calcium oxide, and silicon dioxide, and molten silicon respectively; and (2) the solid oxidized slag containing aluminium oxide, calcium oxide, and silicon dioxide, and the molten silicon are separated so as to obtain the solid oxidized slag containing aluminium oxide, calcium oxide, and silicon dioxide, and the molten silicon respectively. The method is capable of increasing removing rate of aluminium, calcium, phosphor, and boron impurities of the silicon liquid substantially, and silicon recovery rate of the obtained molten silicon can be as high as 86%.

Description

technical field [0001] The invention belongs to the technical field of non-ferrous metal smelting, in particular, the invention relates to a method for processing silicon liquid. Background technique [0002] At present, the silicon liquid containing impurities produced in the domestic industrial silicon production process usually adopts the traditional extensive oxidation refining method. In the practical application of this refining method, the refining time is long and the silicon loss rate is large. In addition to the inconvenient operation, the formed tailings are not easy to separate from the silicon melt, which makes it difficult to improve the purity of the silicon liquid. The tailings of the tailings contain a considerable amount of silicon, resulting in the loss of silicon resources, and the increase in unit consumption and cost of the product; at the same time, due to insufficient control of trace elements such as P and B, the obtained silicon melt cannot fully sa...

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Problems solved by technology

In the practical application of this refining method, the refining time is long and the silicon loss rate is large. In addition to the inconvenient operation, the formed tailings are not easy to separate from the silicon melt, which makes it difficult to improve the purity of the silicon liquid. The tailings of the tailings contain a considerable amount of silicon, resulting in the loss of silicon resources, and the increase in product unit consumption and cost; at the same time, due to insufficient control of trace elements such as P and B, the resulting silicon melt cannot fully satisfy the requirements of metals. Silicon downstream industry chain and other production requirements

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