Method for producing pre-coating primer by utilizing waste phosphating solution

The invention provides a method for producing a pre-coating primer by utilizing a waste phosphating solution, and belongs to the field of industrial phosphating solution. The method comprises: (1) determining the pH value of the waste phosphating solution, charging an alkaline substance, adjusting the pH value of the waste phosphating solution to 8 to 10, standing, filtering, recovering the filtrate for phosphating process, and recovering filter slag for producing the pre-coating base paint; (2) drying the filter slag in a drying oven for 1.5 to 2 hours under 80 to 100 DEG C, charging an appropriate amount of pre-coating base paint additives, heating in a reaction kettle to 70 to 90 DEG C, mixing for 30 to 40 minutes, and naturally cooling to obtain the pre-coating base paint. According to the method, the waste phosphating solution is recycled, the filter slag is used for regenerating the pre-coating base paint, the filtrate is recovered for the phosphating process to be recycled, the emission of sewage can be greatly reduced, energy can be saved, the emission can be reduced, and environment can be protected; the adhesion force of the pre-coating base paint produced by the filter slag is grade A, the water resistance is high, the covering property is good, and the comprehensive performance is good; the method is simple, wide in application range, low in cost and favorable for the industrialized production.