The invention discloses an online forecasting method of a pH value of ore pulp in a
bauxite flotation process. Aiming at the problem of
lag of the pH value control due to relatively large
time lag from the adding moment of a
bauxite flotation ore pulp pH value
regulator to the detecting moment of the pH value and the problem of low manual detection efficiency of the pH value, the method comprises the following steps: firstly building an ore alkali consumption regression model caused by reaction between ores and alkali; then building a pH value mechanism forecasting model according to
hydrolysis of the alkali which does not react with the ores in water and the influence of alkaline circulating water on
hydrolysis balance; building an error compensation model according to an error
time sequence consisting of an actually measured value of the pH value and a forecasting value of the mechanism model; and correcting an error compensation direction according to the change of working conditions based on an expert rule, and compensating the mechanism model by using a corrected compensation value to obtain a forecasting value of the pH value of the ore pulp. The method is used for forecasting the pH value of the ore pulp in an actual production process; a root-mean-
square error is 0.0935, and the maximum relative error is 2.83 percent; and the relative errors of 90 percent of test samples are within + / - 2 percent.