Method for separating aluminum and silicon from solid waste coal gangue

Abstract

The invention provides a method for separating aluminum and silicon from solid waste coal gangue, which comprises the following steps: S1, sequentially carrying out alkali low-temperature activation treatment, hot water dissolution, solid phase separation, liquid phase separation after strong acid addition, and liquid phase separation after strong alkali addition on the solid waste coal gangue; s2, adding a sodium aluminate solution into a liquid phase separated after the strong base is added in the step S1, and placing the liquid phase in a constant-temperature water bath kettle for heat preservation to obtain a mixed solution; s3, adding calcium oxide into the mixed solution obtained in the step S2, continuously stirring, and carrying out ultrasonic treatment to fully react; and S4, filtering the reacted solution to separate a liquid phase from a solid phase, and washing the liquid phase through aluminum precipitation to obtain a pure aluminum-rich product. According to the method, aluminum and silicon are separated from a mixture of sodium aluminate and sodium silicate by using calcium oxide, and the calcium oxide is used for desiliconization, so that the defects of difficult dissolution, complex production process and high energy consumption of a Bayer process, a sintering process and a series-parallel method are overcome.

Description

technical field [0001] The invention generally relates to the technical field of coal gangue development and utilization, in particular to a method for separating aluminum and silicon from solid waste coal gangue. Background technique [0002] Coal gangue is currently one of the largest industrial and mining solid wastes in China. It mainly comes from the coal mining process. It is a solid waste generated during coal production and processing, and is a symbiotic resource of coal. The comprehensive discharge of coal gangue accounts for 10% to 20% of the raw coal output, and more than 1,000 coal gangue hills have been piled up so far. At present, my country has accumulatively stockpiled more than 6 billion tons of coal gangue, and the amount of newly produced coal gangue is increasing at a rate of 100 million tons every year, occupying a large amount of land and causing many environmental problems. [0003] Coal gangue is usually stacked in the open air, and weathering and de...

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Problems solved by technology

[0007] In order to solve the technical problems in the above-mentioned prior art, the present invention provides a method for separating aluminum and silicon from solid waste coal gangue, which can not only solve the problem of a small amount of silicon mixed in the aluminum purified from the mixture of sodium aluminate and sodium silicate It can also purify the aluminum element in the mixture of sodium aluminate and sodium silicate in an efficient, fast, economical and practical way

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