The reason why the polishing agent appears rust red after cement curing is because the iron content in cement is relatively high, so the color of cement will appear rust red after air oxidation.
Methods of removing rust red:
1. Wash the concrete with soapy water first. If there is dirt and dust between the detergent and rust, it will affect the effect of rust removal. Wash and dry the surface before proceeding to the next step.
2. Treat stubborn rust with white vinegar. Pour white vinegar on the rusty surface, let it stand for a few minutes, and then brush it with a wire brush. Rinse with cold water. If the rust is stubborn, you can repeat the above steps.