Method for removing impurity aluminum in alkaline complex compound mixing solution

The invention discloses an eliminating method of impurity aluminum from mixed solution of alkaline complex, which solves the shortage of high eliminating cost of impurity aluminum from mixed solution of alkaline complex. The eliminating method of impurity aluminum from mixed solution of alkaline complex comprises the following steps: (1) tank liquor is filtrated by a frame filter press; (2) aluminum content in the filtered tank liquor is detected through a reverse dropping method, and alkali content is detected through an acid and alkali neutralization; (3) an additive being capable of eliminating aluminum is added into the mixed solution of alkaline complex; the adding amount of the additive is 0.5g/L to 3.5g/L; according to weight percentage, the additive comprises 30 percent of sodium silicate, 10 percent of calcium hydroxide or calcium chloride, 60 percent of polyaluminum chloride or aluminum hydroxide; (4) stirring is carried out for 3 hours under the condition of 0.5MPa of compressed air; (5) a frame fi