EXTRACTION AND CHARACTERIZATION OF HUMIC ACIDS FROM SOME BROWN AND HARD COALS OF TAJIKISTAN

The study of humic acids (HA) is associated with their rich composition, complex structure, and high biological activity. The objects of this research were industrially developed deposits of hard and brown coals, including Shurob, Fon‑Yagnob, Ziddi, Sayod, Nazar‑Ayloq, and Kurtegin. The work focuses on the extraction of humic acids, determination of ash‑forming elements, and investigation of the structural and functional‑group composition of the isolated products.