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Industrial Minerals
Published in Earle A. Ripley, E. Robert Redmann, Adèle A. Crowder, Tara C. Ariano, Catherine A. Corrigan, Robert J. Farmer, L. Moira Jackson, Environmental Effects of Mining, 2018
A. Ripley Earle, Robert E. Redmann, Adèle A. Crowder, Tara C. Ariano, Catherine A. Corrigan, Robert J. Farmer, Earle A. Ripley, E. Robert Redmann, Adèle A. Crowder, Tara C. Ariano, Catherine A. Corrigan, Robert J. Farmer, L. Moira Jackson
Nepheline syenite is used in the manufacture of glass, in ceramic glazes, in tiles, and as a filler in paints and plastics. Production of nepheline syenite rose from 200 kt in 1958 to 600 kt in 1974. Output remained constant at this level until 1980, at which time it dropped significantly. This drop is attributed to the recycling of waste glass.
Minerals
Published in W.S. MacKenzie, A.E. Adams, K.H. Brodie, Rocks and Minerals in Thin Section, 2017
W.S. MacKenzie, A.E. Adams, K.H. Brodie
Nepheline is a feldspathoid mineral. The feldspathoid minerals are similar in chemistry to the feldspars but have less silica. The formula given above is an ideal formula because all natural nephelines contain some potassium. Nepheline is the commonest of the feldspathoids and its occurrence is an indication that the rock in which it occurs is alkali-rich.
Aluminum hydroxide crystallization from aluminate solution using carbon dioxide gas: effect of pH and seeding
Published in Mineral Processing and Extractive Metallurgy, 2021
Valeh Aghazadeh, Somayeh Shayanfar, Peyman Hassanpour
Nepheline syenite (Na3K(Al3SiO4)4) is used to produce alumina (Al2O3) as most important aluminum non-bauxite source, moreover, sodium and potassium carbonate and cement can be produced (Arlyuk and Pivnev 2016). Carbonation is one method used for alumina production from aluminate solution obtained from alkaline leaching of sintered nepheline syenite (Czajkowski et al. 1981). Carbonation of aluminate solution is performed by injection of carbon dioxide gas into the solution. Aluminum hydroxide (Al(OH)3) is precipitated and the residual solution containing carbonate, potassium, and sodium ions is used for production of potassium and sodium carbonate salts (Jorjani and Amirhosseini 2007).
Production and characterisation of sodium and potassium carbonate salts from carbonation alkaline aluminate liquor
Published in Mineral Processing and Extractive Metallurgy, 2021
Shima Barakan, Mehdi Noroozi Ayaluey, Somayeh Shayanfar, Valeh Aghazadeh
The main stages in alumina production from nepheline syenite are grinding of the ore and limestone, sintering of the ground material, dissolution of the sintered materials, desilication, carbonisation, precipitation of aluminate solution, and calcination of aluminum hydroxide (Al(OH)3) (Smirnov 1996; Kazakov and Lipin 2012). Carbon dioxide from the sintering stage is injected into the alkali aluminate solution in the carbonisation stage leading to aluminum hydroxide precipitation. The carbonate ions in this liquor can be extracted as valuable sodium and potassium carbonate salts by-products (Anastasiia 2013). A schematic diagram of the carbonisation and aluminium hydroxide precipitation stages is shown in Figure 1 which shows the reactions occurring at the gas–liquid interface. Based on chemical reactions (1) and (2), sodium and potassium carbonate salts are recovered from sodium and potassium-rich liquor and the aluminate solution is converted into crystalline Al(OH)3 (Chen et al. 2006). To extract the carbonate salt, the solution containing sodium and potassium cations with a negligible amount of bicarbonate anions is evaporated and concentrated in several stages (Polkan et al. 2003). Our findings indicate that there are a few studies on the crystallization of sodium-potassium carbonate salts from the alkali carbonate liquor from the alumina extraction process. In this research, for the first time a study was carried out using thermodynamic modelling and experiments to determine the optimum conditions for carbonate salt extraction. Furthermore, the study investigated the characteristics and properties of the polythermal crystallization, the activation energy, and the effect of solution density and different temperatures on the quality of the carbonate by-products.