ArticleName |
Elemental analysis of phosphorus ores using the tagged neutron method |

Abstract |
The results of the pilot operation of the AGP-F facility in determination of mass fraction of phosphorus pentoxide in phosphorus ores are discussed. The facility operates by the tagged neutron method, irradiates ore with fast neutrons with an energy of 14 MeV and records the characteristic emission of gamma rays from inelastic neutron scattering reactions. The pilot operation of the AGP-F facility at Vostochny Mine of Apatit JSC well demonstrated the main features of the elemental analysis of apatite–nepheline ores using the tagged neutron method. This is primarily the absence of any sample preparation and the ability to determine the elemental composition of samples of large mass (3–5 kg) and size (up to 100 mm). Based on measurements of 75 ordinary samples with a particle size of -10 0 mm, the measurement accuracy was estimated. The absolute value of the standard deviation in the range of P_{2}O_{5} contents of 2–25% is RMSabs = 1.17% P_{2}O_{5} (RMS_{rel} = 8.3%) with a measurement time of 10 minutes. Measurements of the calibration collection of 69 samples with a size of -3 mm showed RMS_{rel} = 3.33% in the range of P_{2}O_{5} of 1-40%. The minimal concentration of P_{2}O_{5} was determined. It was 1.71%. Measurements of 58 samples with size of -100 mm made it possible to determine a transient response that relates the values of the AGP parameter for samples with size of -100 mm and with size of -3 mm. An important result was obtained on the simple linear dependence of this characteristic. It shows that due to the high penetrating power of fast neutrons with an energy of 14 MeV, a natural averaging of the elemental concentration over the entire sample material occurs and the value of the AGP parameter becomes the same for both the large-sized sample and small ones. This result is important to for the future use of TNM for a conveyor system. The tests have fully confirmed the consistency of the tagged neutron method for determining the elemental composition of phosphorus ores. The applicability of the tagged neutron method for determining mass concentrations of 25 chemical elements (Na, Mg, C, N, O, F, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Pb, Sn, Bi, Sb) is verified.
**This article is devoted to the memory of Dr. Phys.-Math. V. M. Bystritsky who greatly contributed to the tagged neutron method development and the AGP-F facility engineering.**
**The authors express their deep gratitude to: S. A. Zhurba and Skolkovo Innovation Center for the ****sponsorship of the pilot facility manufacturing; V. B. Melnik, I. V. Salnikov, I. Yu. Rybin, A. A. Skryabin, ****E. V. Persiyanov, N. B. Domosevich and D. A. Mikhailov from Apatit’s Division in Kirov for the help in ****experimentation; E. A. Andreev, E. V. Zubarev, P. P. Reunov, A. B. Sadovsky and O. G. Tarasov from ****Diamant LLC for the participation in engineering and testing of AGP-F facility.** |

References |
1. Valković V. 14 MeV Neutrons: Physics and Applications. Boca Raton : CRC Press, 2015. 516 p. 2. Fedorov N. A., Grozdanov D. N., Kopatch Yu. N., Bystritsky V. M., Tretyakova T. Yu. et al. Measuring the Yields and Angular Distributions of γ Quanta from the Interaction between 14.1 MeV Neutrons and Magnesium Nuclei. *Bulletin of the Russian Academy of Sciences. Ser. Physics*. 2020. Vol. 84, No. 4. pp. 367–372. 3. Grozdanov D. N., Fedorov N. A., Bystritski V. M., Kopach Yu. N., Ruskov I. N. et al. Measurement of Angular Distributions of Gamma Rays from the Inelastic Scattering of 14.1-MeV Neutrons by Carbon and Oxygen Nuclei. *Physics of Atomic Nuclei*. 2018. Vol. 81, No. 5. pp. 588–594. 4. Rogov Yu., Kremenets V., Sapozh nikov M., Sebele M. Application of Tagged Neutron Method for Detecting Diamonds in Kimberlite. *Instruments*. 2020. Vol. 4, Iss. 4. 33. DOI: **10.3390/instruments4040033** 5. Rogov Yu. N., Sapozhnikov M . G., Nikitin G. M., Yamov A. V. Application of the tagged neuron method to dry processing of kimberlite. *Gornyi Zhurnal*. 2018. No. 5. pp. 58–62. DOI: **10.17580/gzh.2018.05.08** 6. Bolsh akov I., Kolesnik M., Sor okin M., Kremenets V., Razinkov E. et al. Application of Tagged Neutron Method for Element Analysis of Phosphorus Ore.* International Journal of Mineral Processing and Extractive Metallurgy*. 2020. Vol. 5, Iss. 4. pp. 54–59. 7. Pino F., Fontana C. L., Nebbi a G., Pedersen B., Varasano G. et al. Detection module of the C-BORD Ra pidly Relocatable Tagged Neutron Inspection System (RRTNIS).* Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment*. 2021. Vol. 986. 164743. DOI: **10.1016/j.nima.2020.164743** 8. Bystritsky V. M., Rogov Yu. N., Sadovsky A. B., Sapozhnikov M. G., Nikitin G. M. Application of the tagged neutron method for diamonds detection in kimberlite.* Proceedings of XXIX International Mineral Processing Congress*. Moscow, 2018. pp. 683–689. 9. Bishnoi S., Patel T., Thomas R. G., Jilju R., Sarkar P. S. et al. Study of tagged neutron method with laboratory D-T neutron generator for explosive detection.* The European Physical Journal Plus*. 2020. Vol. 135, Iss. 5. 428. DOI: **10.1140/epjp/s13360-020-00402-y** 10. Bystritsky V. M., Bystritskii Vit. M., Dudkin G. N., Filipowicz M., Gazi S.et al. Effect of the Crystal Structure of a Deuterated Target on the Yield of Neutrons in the dd Reaction at Ultralow Energies. *Journal of Experimental and Theoretical Physics Letters*. 2014. Vol. 99. Iss. 9. P. 497–502. 11. Fedorov N. A., Tretyakova T. Yu., Bystritsky V. M., Kopach Yu. N., Ruskov I. N. et al. Investigation of Inelastic Neutron Scattering on 27Al Nuclei.* Physics of Atomic Nuclei*. 2019. Vol. 82, No. 4. pp. 343–350. 12. Pesente S., Nebbia G., Viesti G., Daniele F., Fabris D. et al. Progress in tagged neutron beams for cargo inspections.* Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions **with Materials and Atoms*. 2007. Vol. 261, No. 1-2. pp. 268–271. 13. Aleхakhin V. Y., Bystritskii V. M., Zamyatin N. I., Zubarev E. V., Krasnopyorov A. V. et al. Determination of the elemental composition of geological rocks and minerals by the method of tagged neutrons. *Fundamental Interactions & Neutrons, Nuclear Structure, Ultracold Neutrons, Related Topics: 23*^{rd }*International Seminar on Interaction of Neutrons with Nuclei*. Dubna, 2015. 14. Babin G. V., Khalimon V. I. Analysis of methods for spectra deconvolution in experiments with tagged neutron use.* Izvestiya Sankt-Peterburgskogo gosudarstvennogo tekhnologicheskogo instituta **(tekhnicheskogo universiteta)*. 2014. No. 26(52). pp. 102–108. |