TECHNOLOGIES FOR PHOSPHORIC ACID PRODUCTION: A REVIEW

Abstract

Introduction:
Phosphoric acid is a strategic raw material for fertilizers, the food industry, and lithium batteries. The selection of its production technology constitutes a multidimensional decision conditioned by local inputs, quality, and sustainability.
Objective:
To compare the main technologies for phosphoric acid production from phosphate rock and their adaptation to the Cuban context.
Materials and Methods:
A qualitative narrative review through systematic search in Scopus, Web of Science, ScienceDirect, PubMed Central, ACS Publications, and Google Scholar, complemented with technical reports and patents.
Results and Discussion:
Four technologies were analyzed: wet process with sulfuric acid (dihydrate and hemihydrate-dihydrate variants), hydrochloric acid route with solvent extraction, thermal process in an electric arc furnace, and microbial bioleaching. The wet process, dominant worldwide (>90 %), presents critical barriers for Cuba: dependence on imported H₂SO₄, low grade of local rock (15-22 % P₂O₅), and phosphogypsum generation. The HCl route eliminates phosphogypsum, is compatible with high Fe/Al rock, and utilizes locally available HCl. The thermal process requires prohibitive energy consumption. Bioleaching is emerging, with low environmental impact, but insufficient technological maturity for immediate industrial scale.
Conclusions:
No technology is universally optimal; the hydrochloric acid route is the most suitable for Cuba, and bioleaching utilizing endemic microbiota constitutes the innovation line with the greatest potential in the medium and long term.