Sulfuric acid flow-rate control method for dihydrol wet-method phosphoric acid extraction process

The invention discloses a sulfuric acid flow-rate control method for a dihydrol wet-method phosphoric acid extraction process. The method comprises the following steps: detecting CaO mass concentration of ore pulp input to a phosphoric acid extract trough, and converting the CaO mass concentration into the consumption amount of sulfuric acid needed by the CaO; detecting impurity mass concentration of the ore pulp input to the phosphoric acid extract trough, and calculating the consumption amount of sulfuric acid needed by the impurities in a fuzzy reasoning manner; adding up the consumption amounts of the sulfuric acid to obtain the total consumption amount of the sulfuric acid; detecting content of sulfuric acid of the ore pulp output from the phosphoric acid extract trough, calculating a correction coefficient, and correcting the total consumption amount of the sulfuric acid by virtue of the correction coefficient; measuring the flow rate of ore pulp input to the phosphoric acid extract trough, and multiplying the corrected total consumption amount of the sulfuric acid by the flow rate of the ore pulp; and converting the multiplication result to a control current signal so as to control the openness of an electric adjusting valve of the flow rate of the input sulfuric acid. By adopting the sulfuric acid flow-rate control method, the stability of technical indexes can be effectively improved, the quality and economic benefit of a final product can be improved, the consumption of the sulfuric acid is reduced, the environmental pollution is reduced, the automation degree is high, and simplicity in operation is achieved.