Yes you can use materials found in the trash to recycle into artwork. Here is an assignment that was shared with my art class.
Objective: Use found materials to create a 3D form
Look for interesting materials that can be combined into a dynamic sculptural forms. Artists have been recycling before it became popular.
Use everyday objects that have been used for another function. Now alter the use of the objects into a new visual context. The intent is to cause the viewer to see what you have made in a fresh new way.
Look at what Pablo Picasso did with sheet metal and wire in the work called the “Guitar” Below.
Materials: Use only materials that you find and not purchased. This project should take less than 10 hours.