Method and system for producing sodium sulfide by reducing sodium sulfate

Abstract

The application discloses a method and system for preparing sodium sulfide by reducing sodium sulfate, and belongs to the field of inorganic chemical products. The method comprises the following steps: mixing fuel and air to obtain high-temperature flue gas; obtaining high-temperature reducing gas by heat exchange of the high-temperature flue gas and the heating reducing gas; under the indirect heating of the high-temperature flue gas, preheating sodium sulfate raw materials and mixing the high-temperature reducing gas, and completing the gas-solid reaction to generate sodium sulfide in a dilute phase conveying state under the carrying of the high-temperature reducing gas; gradually preheating the powdered sodium sulfate raw materials by the high-temperature flue gas to obtain preheated sodium sulfate raw materials; carrying out gas-solid separation on the reducing waste gas carrying the sodium sulfide; gradually cooling the high-temperature sodium sulfide obtained by the gas-solid separation by direct heat exchange with low-temperature inert gas to output the sodium sulfide product, and obtaining the heating inert gas. The application has the advantages of short reduction reaction time, high reaction efficiency, high thermal efficiency, simple preparation process, high purity of the obtained sodium sulfide, and high product value.

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