Behavior of Monazite Components in Humic Acid Solutions

摘要

Phosphate ceramics, due to their high stability and low solubility in water and mineral acids, are used as biomaterials, dental ceramics, as well as building and heat-resistant materials [1, 2]. Structural and radiation stabilities of phosphates cause the interest in these materials as matrices for immobilization and long storage of high-level radioactive actinides [1,3, 4-6] and sorbents for soil microelements to decrease their assimilability in plants [7,8]. The storage of phosphate compounds in natural environment suggests their contact with soil, surface, and subsoil waters, which contain complexing inorganic anions and organic substances dissolved, mainly humic substances-fulvic and humic acids (HAs). The latter substances are natural polyfunctional complexing agents [9, 10]. However, we have found no data in the literature giving an estimate of physicochemical consequences of the interaction of humic acids with components of inorganic minerals due to the complex formation.