Technology with Innovation

HIBLEACH™ Bleaching Technology

In addition to color pigments, Bleaching also removes residual phosphatides, metal contaminants, soaps and oxidation products.




  • Oil undergoes Pre-treatment with Phosphoric acid/citric acid and the pre-treated oil is given a pre-determined retention before going to the Bleacher. This step splits soap and traps metal contaminants.
  • The pre-treated oil is mixed with bleaching earth in inline static mixer, where oil and bleaching earth is formed before enteringthe Bleacher.
  • HIBLEACH™ Bleacher is equipped with mechanical agitation and steam sparging for better contact between oil and bleaching earth. Bleacher is kept under vacuum of 710 mm Hg. A retention time of 40 - 60 minutes is given to slurry for efficient contact and adsorption of color pigments and other impurities on to the Bleaching earth.
  • The slurry is then sent to Pressure Leaf Filters for filtration of bleaching earth from oil, followed by polish filtration. The spent cake is then dried by steam blowing to remove oil from wet cake.


Salient features
  • Pretreatment of Oil to eliminate metal contaminants and residual P-contents
  • Slurry preparation & Bleaching in single reactor – Compact system
  • No carryover of bleaching chemical to Vacuum system
  • Wet Bleaching with effective mechanical agitation
  • Enhanced adsorption of coloring matters by bleaching earth
  • Lower consumption of Bleaching earth
  • Ensure accurate (Automated) dosing system of Bleaching earth
  • Lower consumption of utilities


Optional Systems offered Stages


  • Silica pre-treatment eliminates water-washing step in Long-Mix refining
  • Pre-filtration of oil by re-using spent bleaching earth. This reduces bleaching earth consumption and oil losses
  • Activated carbon dosing system in the same Bleacher
  • Upgradation or modifications of existing Bleaching process.
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