ABSTRACT
Manufacturing of single superphosphate has been accomplished over the years with many types of mixers and dens. This chapter examines the various methods to accomplish these requirements using a TVA-type cone mixer and a belt den. The lower limit would be the point that an unacceptable amount of unacidulated dust would pass through the open vortex that would exist in the center of the discharge nozzle at the lower production rate. A belt den that contains the material in a deep trough is most suitable for this service. Belting materials that became available in the last few years made belt dens a practical possibility. A belt den, in combination with a cone, probably places less demand on operating and maintenance personnel than any other system used to make superphosphate. Batch dens of the same overall rate of production produce much higher peak gas loads.
