Try CLR or an OXY cleaner.
To remove rust stains from concrete lions, you can try using a mixture of white vinegar and baking soda. Scrub the affected areas with this mixture using a brush or sponge, then rinse thoroughly with water. For tougher stains, you may need to use a commercial rust stain remover specifically designed for concrete surfaces.
Try some CLR, calcium lime rust remover
CLR its found at most harware stores. scouring stone
Try CLR. It removes rust from many things without damage.
CLR (Calcium Lime Rust) cleaner typically has a pH of around 2-3, making it quite acidic. This acidity allows it to effectively dissolve and remove mineral deposits, rust stains, and lime scale.
You may need to replace it but you can remove it and try CLR and then rinse it really well.
There are a number of products commercially available in hardware stores and in the cleaning product section of supermarkets. One such product is CLR which advertises for removing Calcium or Lime deposits, or Rust stains.
CLR is a household cleaner used for removing Calcium, Lime, and Rust. It's commonly used for Kitchens and bathrooms.
Use limeaway (the concentrated type) or clr (concentrated). Both work pretty well. They are very strong and can be bought at home depot or lowes.
You can remove rust stains from concrete by using a commercial rust remover or a mixture of vinegar and baking soda. Apply the solution to the stained area, scrub with a brush, and rinse thoroughly with water. Repeat as necessary until the stain is gone.
One effective solvent for removing rust stains is white vinegar. Simply soak a cloth in vinegar and place it over the rust stain. Let it sit for a few hours before scrubbing the area with a brush or cloth. Repeat as needed until the rust stain is removed.