MgO & P₂O₅ in Phosphate Rock

Scope

The measurement of the control oxides P₂O₅ and MgO is demonstrated, as well as other major oxides in phos rock.

Background

Phos rock (phosphate rock, rock phosphate, phosphorite) is mined from high phosphorous clay deposits and processed to be used in fertilizers. During mining and processing it is critical to measure and monitor the levels of P₂O₅ and MgO, as well as the other major oxides CaO, Al₂O₃, SiO₂, and Fe₂O₃ to ensure proper product quality of the physical and chemical properties desired. To meet this industry need, Rigaku offers NEX QC+ EDXRF analyzer. The self-contained unit with touchscreen operation is ideal for at-line quality checks by non-technical operators, as well as in the QA/QC lab.

Model: NEX QC+

Calibration

For demonstration, an empirical calibration was built using a set of seven commercially available standards. Two of the calibration standards are certified reference materials. Boric acid was measured to generate special background correction that automatically compensates for the specific amount of background in each individual sample measured.

Control Oxides

Correlation plot P₂O₅

Correlation plot MgO

Other oxides

Repeatability

To demonstrate repeatability (precision), the low and high calibration standards were chosen. Each sample was measured in static position for ten repeat analyses with typical results shown below.

Conclusion

The performance shown here demonstrates NEX QC+ provides excellent sensitivity and performance for the measurement of P₂O₅, MgO and other major oxides in phos rock. Self-contained with simple touch screen operation, NEX QC+ is an excellent tool for at- line control and quality checks throughout the mining and processing of phos rock.