Environmental Footprint of the Improved Hard Process


  • The production of 5–7 tonnes of a calcium silicate aggregate (J-ŸRox) accompanies the production of IHP phosphoric acid.  Toxicity Characteristics Leaching Procedure (TCLP) testing of JŸ-Rox indicate almost no leaching of  hazardous substances – far below regulatory limits.  Radiological testing (radon emanations) of JŸ-Rox indicate radiation levels of about 3% of natural background and about 10% of federal dosage limits – radiation levels are far below regulatory limits (tests conducted by SENES Consultants and SRC Analytical).
  • The process is designed for zero discharge of process wastewaters (process waters can be reused within the plant).
  • Carbon dioxide emissions:
Source Million Tonnes CO2 Percent of Global
Global CO2 Emissions 34,500 100%
United States CO2 Emissions 5,383 15.6%
Cement Industry CO2 Emissions 1,725 5.0%
IHP CO2 Emissions
   – Industry Conversion (40 Million Tonnes P2O5) 98.18 0.285%
   – Commercialization Example (4 Million Tonnes P2O5) 9.82 0.028%
   – Single 200,000 Tonne IHP Plant (0.2 Million Tonnes P2O5) 0.49 0.001%

KPA White Paper

History, Development, Status and Opportunities for Kiln Phosphoric Acid