Characteristics of HACaP complexes prepared from lignite humic acids

Calcium humate phosphorates, HACaP were prepared by direct interaction of humic acids (HA) from lignite, calcium ions and phosphate at pH 5 and 7. The complexes have been isolated by dialysis and their electrophoregrams and thermograms have been obtained. The phosphorus availability in the HACaP complexes was estimated by six selected extractant solutions of very different pH. The electrophoregram of the HACaP complex prepared at pH 7 shows simultaneous movement of phosphorus and HA and the differential thermogravimetric (DTG) curves indicated a slight decrease of the temperature of nucleus decomposition with respect to calcium humate. The study of phosphorus availability indicated that in the complexes, it is in available form.