Kenny - I think we need more information. Got pictures? Are all the used tires the correct size for your bike? Does your bike even need to have it's tires replaced? If your current tires have plenty of tread left and they don't look like trash, then your friend can keep his box of hazardous waste ...
HOWEVER, if he frequently replaces his tires then you might have a box of gold! Look for a sweet pair that match!