Brazil is the seventh-largest phosphate producer globally, contributing to almost 3% of total production. Approximately 20% of the country's phosphate output comes from sedimentary sources, while the remaining 80% is of magmatic origin. The growing demand for phosphate has sparked increased interest in identifying new deposits. In northwestern Brazil, a phosphate rocks in the São Benedito Formation, part of the Alto Tapajós Group in the Apuí region of Amazonia, has attracted attention.Twelve outcrops were collected for mineral and chemical analysis, solubility testing in aqueous media, standard tests using citric acid, and P2O5 release kinetics. The raw material consists of compacted gray quartz sandstone containing fluorapatite, glauconite, and siderite. The raw samples exhibited total P2O5 content of up to 6%. Additional elements were assessed, with only CaO and Fe2O3 showing total contents reaching 8.05 wt% and 6.65 wt%, respectively. Kinetic extraction in a 2% citric acid solution revealed a positive correlation between soluble and total contents of CaO and P2O5 indicating apatite composition. The elements showed solubility exceeding 60% within the first 30 min and reaching 100% after 180 min. However, as the fluorapatite and siderite dissolved, the citric acid solution became saturated, halting the dissolution process. These results indicate effectiveness in solubilizing phosphate in samples with less than 4 to 5 wt% of P2O5, meeting the minimum requirements established by the Brazilian Ministry of Agriculture. These characteristics suggest that the São Benedito Formation phosphate rocks have agronomic value for use as direct/natural fertilizers in Brazil's tropical acidic soils.