No abstract

The desliming operation to discharge ultrafine particles less than 20 µm prior to concentration by flotation is a common practice in phosphate ores beneficiation plants. The first industrial application for the beneficiation of the phosphate material with particle sizes <44 µm in Brazil was in the Araxá plant concentrator in the beginning of the 1980s. This work shows the comparative flotation results with two different phosphate slime samples (<40 µm) obtained from the Copebras (CMOC International) industrial plant located in Catalão (Goiás state, Brazil), considering a circuit with rougher/cleaner configuration with different columns sizes, as follows: Circuit 1 (rougher—4” diameter column; cleaner—2” diameter column) and circuit 2 (rougher—6” diameter column; cleaner 4” column). The results indicate that better flotation apatite recovery results were achieved for the circuit with higher size columns (6” and 4”). The results can be explained by the application of a cavitation tube in the rougher stage in the 6” column. The improved flotation performance can be attributed to increased probabilities of collision and attachment and the reduced probability of detachment by the small size bubbles generated by the cavitation tube in comparison with the bubbles produced by the porous tube of the 4” column flotation.

No abstract

No abstract

No abstract

No abstract

The flotation process currently considered for apatite concentration from the Santa Quitéria phosphate deposit (Brazil), involves bulk flotation of apatite and calcite with anionic collector at pH=10 followed by calcite flotation at pH=5.5, adjusted with H 3 PO 4. Although this concept is efficient from the point of view of separation between apatite and calcite, the intensive use of inorganic acids causes ion accumulation in the process water, especially Ca 2+ and PO 4 2-, which leads to problems in the flotation stage as well as in the environment. CETEM has been studying a process for the separation of carbonate minerals and apatite that involves the use of carbonic gas injected into the bubble generation system of flotation machines instead of inorganic acids. The aim of this study was to evaluate the effect of Ca 2+ ion concentration on the water during the calcite flotation stage of the Santa Quiteria phosphate ore, between 6 mg/L (standard test) and 670 mg/L (maximun concentration) on the flotation performance in terms of P 2 O 5 grade and its loss and the CaO/P 2 O 5 ratio (RCP). The results indicated a reduction in the selectivity on the flotation of calcite from apatite for Ca 2+ concentrations from 6 mg/L to around 285 mg/L. Despite this, the results obtained in this study indicated that the process based on the application of CO 2 for the separation of calcite and apatite may be a technical alternative that causes less impact in flotation performance for the phosphate concentration ores with carbonated gangue.

No abstract