Method for continuous extraction production of instant sodium silicate from fly ash

The invention relates to a method for continuous extraction production of instant sodium silicate from fly ash, belonging to the technical field of resource recycling of sodium silicate. The method comprises the following steps: adding liquid caustic soda into the fly ash to prepare desiliconization liquid; performing evaporation concentration of the desiliconization liquid; preparing a compound extraction agent; adding the concentrated desiliconization liquid into the compound extraction agent; diluting the primary sodium silicate solution with the water generated by the evaporation concentration; and adding the primary sodium silicate dilute solution into the compound extraction agent and repeating to finish the continuous extraction process. The method provided by the invention can realize resource recycling of sodium silicate; high alkali recovery rate can be kept while a high value-added instant sodium silicate product can be produced, wherein the product contains 18-28% of Na2O and 48-65% of SiO2, and 85-96% of alkali is recycled; and the technical difficulty of the prior art that a large amount of raw material alkali is wasted when acid or carbon dioxide gas is added to increase the modulus of the desiliconization liquid is overcome, and the consumption of alkali is reduced. Moreover, the generation of a large quantity of salt-containing wastewater is avoided, and the product revenue is increased while the production cost is reduced.