Yes, old doorknobs can be recycled and can be used in a variety of ways around the house for the best results. This helps to boost your home improvement needs and then use the existing resources in the best way and that too on a budget.
Firstly, you need to identify if the same is reusable. If yes, you may opt to use these as coat hangers, tie knobs or even to hang knick-knacks around the house. Similarly, you can opt these for hanging out pots and pans around the garden area and get the most quirky results for your home and that too on a budget.