Method for controlling content of acid-soluble aluminum in plate blank

The invention provides a slab acid-soluble aluminum content control method which comprises the following steps: the acid-soluble aluminum content of converter tapping molten steel is controlled to be A + 0.009%-A + 0.0120%, the oxygen content of the converter tapping molten steel is 700-900 ppm, and the temperature of the converter tapping molten steel is 1590-1620 DEG C; a is the target content of acid-soluble aluminum of the plate blank, and 0.018% < = A < = 0.020%; the converter tapping molten steel is refined until the content of acid-soluble aluminum in the converter tapping molten steel is controlled to be A + 0.0030%-A + 0.0045%, refined molten steel is obtained, and the refining treatment time is 25-35 min; the content of acid-soluble aluminum in the refined molten steel is controlled to be A + 0.0010%-A + 0.0020%, and molten steel to be poured is obtained; and the to-be-poured molten steel is poured to obtain a plate blank. By means of the method, the proportion of tundish molten steel aluminum can b