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Phosphate Fertilizer Recycling and Recovery from Phosphate Mine and Mining Waste
Published in Hossain Md Anawar, Vladimir Strezov, Abhilash, Sustainable and Economic Waste Management, 2019
Hossain Md Anawar, Golam Ahmed, Vladimir Strezov
There are several types of minerals in different deposit environments as follows (Straaten 2002): Flour-apatite (Ca10(PO4)6F2) minerals are found mainly in igneous and metamorphic environments such as carbonatites, and mica-pyroxenites.Hydroxy-apatite (Ca10(PO4)6(OH)2) minerals are found mainly in igneous and metamorphic environments, but also in biogenic deposits, e.g. in bone deposits.Carbonate-hydroxy-apatite (Ca10(PO4,CO3)6(OH)2) are found mainly on islands and in caves, as part of bird and bat excrements, guano.Francolite (Ca10−x−yNaxMgy(PO4)6−z(CO3)zF0.4zF2) apatite mineral is found only in marine environments, and, to a much smaller extent, in weathered deposits, for instance over carbonatites.Dahllite 3Ca3 (PO4)2·CaCO3 phosphate mineral is found in the marine sediments.Collophane (3Ca3(PO4)2·nCa(CO3,F2,O)·xH2O) phosphate minerals is typical of the marine phosphate sediments.
Sulfo-phosphoric attack of the phosphate ore: energetic contribution of each phenomenon intervening during the attack and effect of the time of addition of the sulfuric acid
Published in Journal of the Chinese Institute of Engineers, 2023
Khemaies Brahim, Maher Manai, Amira Soussi-Baatout, Ismail Khattech
Because of the variable composition of natural phosphates as well as the different techniques used, the conclusions drawn from the studies devoted to this subject are usually contradictory. Most of these works were performed discontinuously by taking samples from the solution at various moments. This procedure does not allow giving a real image of what is happening over time. The techniques giving accurate information on what is happening in situ, such as Microcalorimety, are rarely used. A few works were performed using a Calvet microcalorimeter to investigate the kinetics of the attack of phosphates (Brahim et al. 2005, 2020, 2017, 2008). The Differential Reaction Calorimeter (DRC) which is usually used to determine the global amount of heat and can also be of great help for reaction kinetics. Indeed, recently this technique has been adopted for kinetic study of the reaction of the phosphate, from the Gafsa basin, by 25% mass of P2O5 to produce the superphosphate fertilizers, ranging from 25°C to 65°C (Soussi-Baatout et al. 2016). This phosphate, used, after enrichment, by the Tunisian Chemical Group (TCG) to produce phosphoric acid, has a sedimentary origin which is the carbonated fluorapatite (or francolite).
Optimisation of fluorapatite coating synthesis applied to a biodegradable substrate
Published in Surface Engineering, 2019
Malcolm Caligari Conti, Gianella Xerri, Florian Peyrouzet, Pierre Schembri Wismayer, Emmanuel Sinagra, Diego Mantovani, Daniel Vella, Joseph Buhagiar
In Figure 5, the diffractogram for the powder heat treated at 150°C lacks reflections for fluorapatite therefore suggesting that this processing temperature is too low to significantly synthesise any significant amount of crystalline fluorapatite in the coating. When considering the diffractogram obtained from powder treated at 150°C the main peak is found at a higher 2θ value (approx. 33°) compared to the main peak from powders heat treated at 250°C, 500°C and 1000°C. Diffractograms obtained after heat treatment of the powder at the latter temperatures then show a more intense peak for pure fluorapatite with secondary peaks at the higher 2θ angles. This is significant since the peak at higher 2θ angles is representative of a carbonated form of fluorapatite called francolite. The carbonated form generally gives rise to a yellow fluorapatite product, which was observed in our work for powders heat treated to 150°C, 250°C and 500°C. Powders heat treated at 1000°C were observed to be completely white, which Merrhews [33] suggests is the result of the decarbonation of francolite to pure fluorapatite.
The effect of calcium ions on the flotation behavior of fluorapatite
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Mohammed Derqaoui, Imane Aarab, Abdelmoughit Abidi, Abdelrani Yaacoubi, Khalid El Amari, Abderahman Etahiri, Abdelaziz Baçaoui
Fluorapatite or francolite minerals are the primary sources of phosphorus beneficiation from sedimentary phosphate rocks (Emsbo et al. 2015; Kawatra and Carlson 2014), which make up 75% of the global phosphate reserves (Aydin et al. 2009). In the phosphate ores, they are often accompanied by other minerals such as dolomite, calcite, silica, organic matter, clay, and other inorganic compounds (Carlson, Eisele, and Kawatra 2012; Fang and Jun 2011).