Author 1:
Name & Surname: Levin B. V.
Company: Research Institute for Fertilizers and Insectofungicides (NIUIF) (Moscow, Russia)
Work Position: General Director
Scientific Degree: Candidate of Engineering Sciences
Contacts: e-mail: info@niuif.ru

Author 2:
Name & Surname: Kalugin A. I.
Company: Apatit JSC (Kirovsk, Russia)
Work Position: Technical Director—Chief Engineer
Scientific Degree: Candidate of Engineering Sciences

Apatit JSC, the world’s largest producer of apatite concentrate, develops the Khibiny apatite-nepheline ore deposits. The company produces one of the world’s best phosphate fertilizer represented by the apatite concentrate with Р₂O₅ content over 39% and the least content of toxic elements as compared with the other known phosphate concentrates. The characteristics of the marketable apatite concentrates, i.e. Р₂О₅ content and grain-size composition, are mainly conditioned by:
- Material composition, texture and structure of ore, including the size of shots of minerals, first of all, apatite shots;
- Engineering capabilities of processing equipment, mainly, flotation machines;
- Consumer requirements concerned with technology of processing.
The methods of processing of apatite concentrate have evolved. Earlier, apatite concentrates were used to produce superphosphate, which required a fine disperse feedstock, whereas recently the concentrates are mainly processed to obtain wet-process phosphoric acid and compound fertilizers. Grain-size composition of feedstock is the determinant of the apatite concentrate treatment process conditions. The article reports the results of commercial tests of the oversize apatite concentrate treatment by sulfuric and nitric acids. It is emphasized that the equipment currently in use for production of wet-process phosphoric acid and compound fertilizers is totally suitable for the oversize apatite concentrate processing.

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