No abstract

No abstract

The effect of ionic species on the flotation selectivity of apatite was evaluated. Water containing fluoride, calcium, magnesium, and phosphate was used in the flotation experiments carried out in a flotation column for coarse and fine phosphate ore. The selectivity of apatite over ferrous and siliceous gangue was investigated. Coarse and fine ores showed different sensitivities according to the ion concentration. The results clearly showed the harmful effect of the ionic species under study on apatite selectivity. The contaminants responsible for the lowest selectivity ratios for ferrous and silicate gangue were calcium and magnesium, regardless of particle size.

No abstract

No abstract

The use of recycled water in the apatite flotation may result in losses to the process performance due to the presence of ions, residual reagents, finely particulate material, etc. The dissolved air flotation (DAF) has been shown an efficient technique in the wastewater treatment in the removal of these pollutants. The use of anionic collector in DAF process is based on the reaction that occurs between the soybean oil soap (apatite collector) with the calcium present in the apatite lattice making its surface hydrophobic. Therefore, the collector can be an auxiliary in the water softening besides improving the hydrophobicity of the particles to be collected. Thus, this study was aimed at evaluating the effect of an anionic collector used as an auxiliary in the dissolved air flotation process. A central composite design (CCD) was proposed to evaluate the concentration of collector and the effect of pH value on the removal efficiency of calcium, magnesium, fluoride, phosphorous and turbidity present in a wastewater from a fertilizer industry. The results showed a good removal of the contaminants which guaranteed a better quality of water to the process of phosphate rock concentration.

ResumoColunas de flotação de bancada estimam a realidade industrial, gerando resultados com elevado grau de consistência e reprodutibilidade. Diante disso, este trabalho teve como objetivo realizar ensaios exploratórios em uma coluna de flotação de bancada, utilizando minério fosfático ultrafino. Testes preliminares, em célula mecânica, foram executados para determinar o tempo de condicionamento e a dosagem dos reagentes. A condição mais adequada foi 500g/t de amido de milho gelatinizado e 250g/t de Flotigam 5806, condicionados por 5 minutos e 1 minuto, respectivamente. A eficiência da coluna de flotação foi confirmada com base em teores de P 2 O 5 , tomando como referência parâmetros industriais de flotação desse tipo de minério. Analisou-se as variáveis granulometria e vazões de reciclo, de água de lavagem e de ar. O melhor resultado obtido foi vazões de ar, reciclo e água de lavagem de 1,2 L/min, 0,95 L/min e 0,1 L/min, respectivamente, correspondendo a um teor de P 2 O 5 de 36,91% no concentrado e 3,53% no rejeito, com recuperação metalúrgica de 74,36%. Palavras-chave: Flotação; Coluna; Fosfato. EXPLORATORY TESTS BENCH FLOTATION COLUMN WITH ULTRAFINE PHOSPHATIC ORE AbstractBench columns flotation simulate industrial reality generating results with high reproducibility and consistency. Thus, this study aimed to perform exploratory tests in a bench column flotation using ultrafine phosphatic ore. Preliminary tests were performed in mechanical cells in order to define the conditioning time and reagents dosage. The most appropriate situation was 500 g/t of gelatinized corn starch and 250 g/t of Flotigam 5806, conditioned for 5 minutes and 1 minute, respectively. The efficiency of the column flotation was established based on P 2 O 5 based in industrial flotation parameters for this type of ore. It was analyzed the particle size and flow recycle of wash water and air. The best result was obtained for air, recycle and wash water flow rates of 1.2 L/min, 0.95 L/min and 0.1 L/min, respectively. Representing a content of 36.91% P 2 O 5 in the concentrate, and 3.53% in the waste with metallurgical recovery of 74.36%.

No abstract