Two of the primary waste components of the Phosphates benefaction process, sand and clay have been used as building materials for thousands of years. A process known as rammed earth has been used extensively around the world in buildings that have lasted for centuries. Because earth is the main ingredient in rammed earth it has recently enjoyed new popularity as a so called “green” building material. In a similar process earth is compressed into blocks which are then used in the same way as conventional masonry units to build walls. In the compressed earth block [CEB] method, individual units can be manufactured and stockpiled for later use rather than being fabricated on site as in the rammed earth process. This research project will investigate the potential use of waste clay and tailing sand from the phosphate benefaction process as the primary ingredients in compressed earth blocks for commercial and residential construction projects.