Valorization of Seaweeds Biomass as Source an Eco-Friendly and Efficient Depressant of Calcite in the Flotation of Apatite Containing Ore

The green selective flotation of apatite from carbonaceous phosphate ores has gained increased scientific and political interest. In this study, Moroccan unexploited seaweeds biomass, as source sodium alginate, an eco-friendly and efficient depressant of calcite in the direct flotation of fluorapatite, were investigated. Extracted sodium alginate E.SA from Saccorhiza polyschides was studied to define its physicochemical properties and assessed its depression effectiveness on two pure specimens of fluorapatite and calcite through micro-flotation tests. Commercial sodium alginate was applied for comparison. The results showed a high selective separation of fluorapatite from calcite was achieved (74%) with 80 mg/L of the extracted alginate E.SA as compared to commercial alginate Co.SA (65%), in presence of 30 mg/L sodium oleate as collector at pH 10. The adsorption mechanism was investigated by additional measurements of adsorption amount, zeta potential, contact angle and FTIR studies, which showed that highly charged E.SA depressant with a higher molecular weight strongly adsorbed on the calcite surface by chelating with calcium species, resulting in the decrease of their hydrophobicity even in the presence of NaOL collector. However, it exhibited less affinity to fluorapatite. [GRAPHICS] .

Automated summary

Moroccan unexploited seaweeds biomass could be a potential eco-friendly and efficient depressant in the green selective flotation of apatite.