Synthesis of thermophosphate fertilizers by a plasma torch.

Abstract

Phosphoric rock (PR) is the basic building block to produce animal feed, fertilizers, and industrial phosphates. Global demand for PR is estimated to grow from 207 Mtons in 2018 to 263 Mtons in 2035, of which Colombia contributes approximately 0.06 Mtons per year. A novel technology to carry out calcination is the plasma torch, where the electrical resistivity of the system is increased and ionized gas is produced that can reach temperatures above 10,000 °C, which facilitates the transformation of PR into thermophosphates. Two samples of PR from the region central of the Boyacá department, Colombia, were subjected to calcination through a plasma torch and as a result, showed a maximum concentration of total phosphorus between 27 – 33 % of P2O5 and assimilable phosphorus corresponding to the range 3.0 – 4.8 % of P2O5 respectively. Finally, the energy consumption for calcination is ≤ 1.14 kW-h/Kg, respectively.