Method for preparing crystal in sodium stannate production process

The invention discloses a method for preparing crystals in a sodium stannate production process, which comprises the following steps: adding a sodium stannate solution into a sodium stannate crystallization device, heating and concentrating to reach saturation concentration, adding an alkaline substance to crystallize and separate out sodium stannate, and the sodium stannate crystallization device comprises a reaction bin, a discharging mechanism, a stirring mechanism and the like. When sodium stannate is manufactured, alkaline substances are placed on the material placing table and then conveyed to the outer side of the stud through the screw rod, the transmission belt drives the worm to rotate under the rotation of the motor, teeth on the side wall of the worm drive the worm wheel to rotate, the stud starts to rotate under the driving of the worm wheel, and the threads on the outer wall of the stud can convey objects on the material placing table to the feeding pipe; the double-screw bolt is arranged in the