Silica, Alkali Carbonate and Alkali Rich Metal Ore as Additive Effect on the Carbothermic Reduction Process of Phosphorus Ore

Abstract

The phosphorus production industry is energy-intensive, which is one of the major reasons phosphorus has lower yields through furnace production. In this study, phosphorus conversion rate from phosphorus ore was investigated using four different fluxing agents: silica, potassium shale, potassium feldspar, and nepheline. Different holding times (10, 20, 30, and 40 min), acidity values (0.68, 0.88, 1.02, 1.42, and 2.02), coal surplus coefficients (1.05, 1.25, 1.5, 2, and 2.5), and calcination temperatures (1250 °C, 1300 °C, 1350 °C, 1400 °C, and 1450 °C) were studied. The results demonstrated that potassium shale, potassium feldspar, and nepheline as new fluxing agents improved phosphorus conversion rate under the same experimental conditions. To further ensure the significance of the experiment, the conversion rate of phosphorus from phosphorus ore was also investigated without an additive and with the addition of Na2CO3 and K2CO3. The slag viscosity of different fluxing agents and different additives at high temperatures was analyzed via the spread area method. To investigate the mechanism of phosphorus conversion, silica and nepheline as fluxing slag at different calcination temperatures were analyzed using X-ray diffraction.