Sometimes empty and worn out,  disposed cartridges are used to manufacture new cartridges. The benefits of recycling cartridges are that they are used instead of sitting in a landfill for years and it avoid exhaustion of fresh material required for manufacturing new cartridges. But the process of grounding up and using them for manufacture,  produces emissions and wastes that are harmful for the environment. It is more safe and economical to reuse and refill cartridge than recycle them.