Based on the experimental data gathered, a conceptualized air pollution control system was established. The system was designed to remove 99% of the fly-ash and 97 1/2% of the sulfur dioxide contained in an assumed but typical flue gas. A venturi-type scrubber was chosen to remove the fly-ash, and tray-type absorber was chosen for sulfur dioxide absorption. A slurry of magnesium oxide and magnesium sulfite is the active absorbent. Drawings show the side and plan views of scrubbing venturis and sulfur dioxide absorbers as integrated into an 800 MW boiler system. The outline and location of the major pieces of equipment are also shown. The cost of the conceptualized system was then developed. Whenever possible, commercially available equipment was utilized in the design and cost estimate. When commercial equipment was not available, suitable conceptual equipment designs were developed, and the cost of the equipment established.