The invention relates to a method for coproducing high-purity methanoic acid and monobasic
sodium phosphate by reaction of
calcium formate and ultraphosphate. The method comprises the following steps that:
carbon monoxide enters a reaction
tower III;
calcium hydroxide enters a reaction
tower I to perform a counterflow reaction with
carbon monoxide from a reaction
tower II, a reaction solution overflows to the reaction tower II to perform the counterflow reaction with the
carbon monoxide from the reaction tower III, the reaction solution enters the reaction tower III to perform the couterflow reaction with the carbon
monoxide, the reaction solution overflows into a
discharge tank from the reaction tower III to prepare a
calcium formate preparation solution; the
calcium formate preparation solution enters a reaction kettle, methanoic acid is dripped into the reaction kettle, sulfureted
hydrogen is introduced into the reaction kettle, the mixture is separated and filtered through a filter I, a filtrate enters a continuous crystallizer, a crystalline liquid enters a filter II, and the filtered
calcium formate is prepared into a finished product
calcium formate through a drier; ultraphosphate, the methanoic acid and the calcium
formate are conveyed into a horizontal double screw reactor to generate the methanoic acid and
monobasic calcium phosphate; the methanoic acid and the
monobasic calcium phosphate enter a methanoic acid distilling still for reduced pressure
distillation; and the
monobasic calcium phosphate is delivered to a monobasic calcium
phosphate measurement receiving tank, while the
monobasic acid enters a methanoic acid receiving tank. The method has high yield of the methanoic acid and low manufacturing cost.