Field testing of the pilot facility AGP-F
The field testing of the AGP-F pilot facility for determining the elemental composition of apatite-nepheline ores at the AO Apatite Vostochny mine was successfully completed.
The control of the phosphorus content in the mined ore is an extremely important task. Up to 30 ore samples are analyzed daily at the mine to determine the content of phosphorus pentoxide (P2O5). For this, ore samples are crushed to a size of -5 mm, dried and measured in a neutron activation unit determining the content of phosphorus pentoxide by correlation with the fluorine content.
The tagged neutron method (TNM) makes it possible to directly determine the elemental content of phosphorus, as well as of 10 more elements: Na, Mg, C, O, Al, Si, K, Ca, Ti and Fe. For this purpose, with the support of the Skolkovo Foundation, an AGP-F pilot facility (Figure 1) was developed, which included a neutron module, an electronics crate and an operator's workplace.
Fig.1 Neutron module and electronics crate.
Ore samples weighing 5-7 kg with a particle size of -100 mm, taken directly from the quarry, without any sample preparation, were placed in the receiving tray of the facility (Fig. 2).
Fig.2 Ore samples in the receiving tray of the facility.
The sample is irradiated with a beam of fast neutrons with an energy of 14.1 MeV, which cause in the sample hard gamma radiation with energies of 1-7 MeV, characteristic for each element. The method of tagged neutrons makes it possible to greatly increase (by 176 times) the signal-to-noise ratio as compared with ordinary irradiation with fast neutrons. The high penetrating power of neutrons and gamma quanta makes it possible to obtain information on the elemental composition of large masses of matter.
For use in the field, the facility was housed in a heated container (Fig. 3).
Fig.3 AGP-F facility at the Vostochny mine of JSC "Apatite".
Comparison of the results of TNM and chemical analysis demonstrated the capabilities of TNM for correct determination of the mass concentration of phosphorus pentoxide in samples of large size (-100 mm) in the field without any sample preparation.
It is planned to conduct in 2018 an experimental operation of the facility at the open mines of JSC "Apatite".