A Review of Industrial Innovations in Phosphate Processing

摘要

This paper reviews significant technological developments in phosphate processing, which have been applied on an industrial scale. It covers phosphate mineral processing, phosphoric acid manufacturing, analysis and process control, and waste treatment and utilization. Nothing improved the industry efficiency more dramatically than the development and commercialization of the Crago "Double Float" flotation process for processing low-grade siliceous phosphate ores. The development and adoption of the direct-reverse flotation process for removing dolomite from sedimentary phosphate has the potential to at least triple the world phosphate reserves. Installations of on-line analyzers based on the NMR (Nuclear Magnetic resonance) and LIBS (Laser Induced Breakdown Spectroscopy) technologies have resulted in significant efficiency improvements. Huge energy saving and environmental benefits have been achieved by the transformation of phosphoric acid manufacturing from the thermal method to the "wet acid" process, which was made possible by industrialization of the dihydrate and hemihydrate processes. Recovery of uranium from phosphoric acid played an important role in increasing the world energy resource. Large scale utilization of phosphogypsum has taken off in many parts of the world. The concept of "green mine" (comprehensive recovery of mineral resources and complete waste utilization) has become a reality at some phosphate complexes.