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Advanced manufacturing and high-quality materials
Published in Natalia Yakovleva, Edmund Nickless, Routledge Handbook of the Extractive Industries and Sustainable Development, 2022
Kazuyo Matsubae, Eiji Yamasue, Hisao Ohtake
In the thermal process, beneficiated phosphate ore with a P2O5 content of about 30% is mixed with coke and silica, sintered in a rotary kiln to form a nugget/pellet, and subjected to a carbothermal reduction in an electric-arc furnace with carbon electrodes. Fluorapatite is converted to calcium phosphate (Ca3P2O8), with hydrogen fluoride generated as a byproduct. Then, calcium phosphate is reduced according to the following reaction: 2Ca3P2O8(s)+6SiO2(s)+10C(s)→6CaSiO3(s)+ P4(g)+ 10CO(g)
F, 9]
Published in Alina Kabata-Pendias, Barbara Szteke, Trace Elements in Abiotic and Biotic Environments, 2015
Alina Kabata-Pendias, Barbara Szteke
Fluorine (F) is an element of the halogen group 17 in the periodic table of elements. Its total content in the upper crust of Earth is estimated at up to 625 mg/kg. In igneous rocks its concentrations vary between 300 and 1200 mg/kg, being the highest in mafic rocks. It is likely to accumulate in argillaceous sediments and in black shales (500–800 mg/kg). Its lowest contents are in calcareous rocks (50–350 mg/kg). Hard coal contains F usually up to 100 mg/kg, but higher contents, up to 200 mg/kg, especially in bituminous coals, are noticed. High levels of F (as fluorapatite and fluorspar) are associated with various phosphate deposits. Fluorine is a common constituent of magmatic and volcanic exhalations, and may also occur in some rocks as gaseous nebulae.
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).