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Hasancan Okutan - One of the best experts on this subject based on the ideXlab platform.
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mechanism of the dissolution of turkish Trona
Hydrometallurgy, 1996Co-Authors: Gulhayat Nasunsaygih, Hasancan OkutanAbstract:Abstract This study measures the rate of dissolution of Turkish Trona as a function of the Trona brine concentration and compares the results with a theoretical model of the rate of dissolution from a vertical wall under conditions of natural convection driven by the density gradient in the boundary layer caused by salt concentration differences. Laboratory dissolution experiments were conducted related to the solution mining of a Turkish Trona deposit. The average rate of dissolution in water was measured to be 2.8 × 10−4 g/cm2 · sec−1 .
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Application of the solution mining process to the Turkish Trona deposit
Hydrometallurgy, 1996Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Abstract This study was conducted to investigate the applicability of the solution mining technique to the Turkish Trona deposit. For this purpose, sesquicarbonate and alkali extraction processes were applied to Turkish Trona. Laboratory experiments were conducted to investigate the dissolution system and the crystallization parameters of these processes. The Trona mineral used for this study was Turkish Trona which had small amounts of sodium chloride and sodium sulphate compared with the Wyoming (USA) Trona. Two crystallization methods were used to produce the crystals: cooling crystallization and evaporative crystallization. The crystals were calcined to produce soda ash.
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DETERMINATION OF DIFFUSION COEFFICIENT OF THE TURKISH Trona IN WATER
Mineral Resources Engineering, 1996Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Laboratory experiments were conducted to measure the diffusion coefficient of the Turkish Trona in water. A rapid and inexpensive method was used for measuring the diffusion coefficient. The procedure consists essentially of soaking a porous disc in the solution of interest and then suspending the disc over a bath of pure water. The rate of diffusion of Trona solution from the disc is then ascertained by measuring the apparent weight of the suspended disc at various times. The rate of change of the apparent weight is directly related to the loss of solute and hence to the diffusion coefficient of the Trona. The diffusion coefficient of Trona from solutions of various concentrations was measured and a linear relationship was found between diffusion coefficient and Trona solution concentration. The average value of diffusion coefficient of Trona was calculated to be 1.194 10−5 cm2/sec at 25°C.
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APPLICATION OF SESQUICARBONATE PROCESS TO BEYPAZARI Trona DEPOSIT: EVAPORATIVE CRYSTALLISATION
Mineral Resources Engineering, 1995Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Laboratory experiments were conducted to investigate the evaporative crystallisation parameters of sesquicarbonate process. Trona mineral used for the study is Turkish Trona mineral, which has small amounts of sodium chloride and sodium sulphate salts compared with Wyoming (USA) Trona mineral. Two evaporation temperatures (45° C and 90° C) were used and the results were discussed.
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APPLICATION OF SESQUICARBONATE PROCESS TO TURKISH Trona DEPOSIT: COOLING CRYSTALLISATION
Mineral Resources Engineering, 1995Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Sesquicarbonate process was applied to Beypazarý Trona deposit. Laboratory experiments were conducted to find the dissolving system for this process. Dissolving temperature was chosen as 90° C and crystallisation temperature as 45° C. Cooling crystallisation was used to produce the sesquicarbonate crystals. The crystals were calcined at various temperatures and soda ash was produced with a yield of over 99%.
G. Nasün-saygili - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature on dissolution of Turkish Trona
Hydrometallurgy, 2003Co-Authors: G. Nasün-saygiliAbstract:Abstract In this study, the rate of dissolution of Turkish Trona was measured as a function of the Trona brine concentration and temperature. The results were compared with a theoretical model of the rate of dissolution from a vertical wall under conditions of natural convection driven by the density gradient in the boundary layer caused by salt concentration differences. The average rate of dissolution in water was measured to be 2.8 g/m2 s. It was found that the temperature is apparently a more important factor at low solution concentrations than at high concentrations.
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Application of the solution mining process to the Turkish Trona deposit
Hydrometallurgy, 1996Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Abstract This study was conducted to investigate the applicability of the solution mining technique to the Turkish Trona deposit. For this purpose, sesquicarbonate and alkali extraction processes were applied to Turkish Trona. Laboratory experiments were conducted to investigate the dissolution system and the crystallization parameters of these processes. The Trona mineral used for this study was Turkish Trona which had small amounts of sodium chloride and sodium sulphate compared with the Wyoming (USA) Trona. Two crystallization methods were used to produce the crystals: cooling crystallization and evaporative crystallization. The crystals were calcined to produce soda ash.
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DETERMINATION OF DIFFUSION COEFFICIENT OF THE TURKISH Trona IN WATER
Mineral Resources Engineering, 1996Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Laboratory experiments were conducted to measure the diffusion coefficient of the Turkish Trona in water. A rapid and inexpensive method was used for measuring the diffusion coefficient. The procedure consists essentially of soaking a porous disc in the solution of interest and then suspending the disc over a bath of pure water. The rate of diffusion of Trona solution from the disc is then ascertained by measuring the apparent weight of the suspended disc at various times. The rate of change of the apparent weight is directly related to the loss of solute and hence to the diffusion coefficient of the Trona. The diffusion coefficient of Trona from solutions of various concentrations was measured and a linear relationship was found between diffusion coefficient and Trona solution concentration. The average value of diffusion coefficient of Trona was calculated to be 1.194 10−5 cm2/sec at 25°C.
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APPLICATION OF SESQUICARBONATE PROCESS TO BEYPAZARI Trona DEPOSIT: EVAPORATIVE CRYSTALLISATION
Mineral Resources Engineering, 1995Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Laboratory experiments were conducted to investigate the evaporative crystallisation parameters of sesquicarbonate process. Trona mineral used for the study is Turkish Trona mineral, which has small amounts of sodium chloride and sodium sulphate salts compared with Wyoming (USA) Trona mineral. Two evaporation temperatures (45° C and 90° C) were used and the results were discussed.
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APPLICATION OF SESQUICARBONATE PROCESS TO TURKISH Trona DEPOSIT: COOLING CRYSTALLISATION
Mineral Resources Engineering, 1995Co-Authors: G. Nasün-saygili, Hasancan OkutanAbstract:Sesquicarbonate process was applied to Beypazarý Trona deposit. Laboratory experiments were conducted to find the dissolving system for this process. Dissolving temperature was chosen as 90° C and crystallisation temperature as 45° C. Cooling crystallisation was used to produce the sesquicarbonate crystals. The crystals were calcined at various temperatures and soda ash was produced with a yield of over 99%.
G J Witkamp - One of the best experts on this subject based on the ideXlab platform.
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mixed solvent reactive recrystallization of Trona sodium sesqui carbonate into soda sodium carbonate anhydrate
Hydrometallurgy, 2007Co-Authors: Robert S Gartner, G J WitkampAbstract:Abstract A new conversion process for the production of soda (Na2CO3(s)) from Trona (Na2CO3·NaHCO3·2H2O(s)) and other sodium bicarbonate containing sodium carbonate sources is presented. By using a mixed solvent consisting of ethylene glycol and water, the boiling point of the solution was increased and the stability of Trona could be decreased to such a degree, that it spontaneously recrystallized to anhydrous soda (Na2CO3(s)) and wegscheiderite (Na2CO3·3NaHCO3(s)). Additionally, the sodium bicarbonate content could be completely decomposed thermally in the mixed solvent into sodium carbonate, which crystallized as stable, pure anhydrous soda. Fundamental mechanisms of this process are discussed: The stability of Trona as a function of mixed solvent composition, water activity and temperature is reported. The dissolution rate, the bicarbonate decomposition rate as well as the (pseudo) solid phase conversion rate of Trona were investigated as functions of mixed solvent composition and temperature. It was found that beyond a certain temperature, depending on the mixed solvent composition, the Trona would convert via the (pseudo) solid state.
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wet calcining of Trona sodium sesquicarbonate and bicarbonate in a mixed solvent
Journal of Crystal Growth, 2002Co-Authors: Robert S Gartner, G J WitkampAbstract:Abstract Trona ore is used in large amounts for the production of soda ash. A key step in this process is the conversion of Trona (sodium sesquicarbonate: Na 2 CO 3 ·NaHCO 3 ·2H 2 O) into soda (sodium carbonate anhydrate: Na 2 CO 3 ). Currently, this conversion is done industrially by calcining of the raw ore in rotary calciners at ca. 120°C or higher (Natural Soda Ash—Occurrences, Processing, and Use, Van Nostrand Reinhold, New York, 1991, p. 267). Trona can however be converted at lower temperatures by using a “wet calcining” technique. In this technique, Trona is contacted with an organic or mixed organic-aqueous solvent at a conversion temperature that depends on the water activity of the used solvent. In pure ethylene glycol this temperature can be as low as 55°C. The conversion by “wet calcining” occurs very similar to that in the regular dry calcining process via a solid phase conversion. The anhydrate crystals form directly from the solid Trona. This produces pseudomorphs (J. Chem. Eng. Data 8(3) (1963) 301), i.e. agglomerates of fine anhydrate crystals (1–10 μm). At high temperatures, dense, finely pored agglomerates are formed, while the outer shape of the agglomerate retains the prism shape of the Trona crystal. At low conversion temperatures, loosely packed or even unstable agglomerates are found.
Timur Dogu - One of the best experts on this subject based on the ideXlab platform.
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kinetics of Trona sulfur dioxide reaction
Chemical Engineering and Processing, 2001Co-Authors: Cigdem Guldur, Gulsen Dogu, Timur DoguAbstract:Abstract One of the most efficient methods of desulfurization of flue gases involves the reaction of SO 2 with activated soda in a dry system. In this work, reactivities of activated soda produced from Trona by direct calcination and by spray drying of Trona solution were compared and a reaction mechanism was proposed. Due to the textural variations of the solid during the reaction and due to the increased significance of adsorption of SO 2 , at low temperatures, a two step reaction behavior was observed. Predictions from the deactivation model gave satisfactory agreement with the experimental data.
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soda ash production from Trona in a spray dryer
Journal of Chemical Technology & Biotechnology, 1997Co-Authors: Meltem Dogan, Cigdem Guldur, Gulsen Dogu, Timur DoguAbstract:Production of soda ash from Trona solution was achieved in a spray dryer reactor. Fractional conversion of NaHCO3 reached to values close to unity in this unit within a residence time of less than a second. Results indicated that above 140°C, heat transfer limitations played a significant role on the calcination process taking place in the spray dryer. Equilibrium limitations may become important only at very low temperatures and at high CO2 and H2O partial pressures. Results obtained in the spray dryer and from the thermal gravimetric analysis of Trona crystals agreed well. It was also shown that the predictions of the unreacted core model are in good agreement with the kinetic data. © 1997 SCI.
Robert S Gartner - One of the best experts on this subject based on the ideXlab platform.
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mixed solvent reactive recrystallization of Trona sodium sesqui carbonate into soda sodium carbonate anhydrate
Hydrometallurgy, 2007Co-Authors: Robert S Gartner, G J WitkampAbstract:Abstract A new conversion process for the production of soda (Na2CO3(s)) from Trona (Na2CO3·NaHCO3·2H2O(s)) and other sodium bicarbonate containing sodium carbonate sources is presented. By using a mixed solvent consisting of ethylene glycol and water, the boiling point of the solution was increased and the stability of Trona could be decreased to such a degree, that it spontaneously recrystallized to anhydrous soda (Na2CO3(s)) and wegscheiderite (Na2CO3·3NaHCO3(s)). Additionally, the sodium bicarbonate content could be completely decomposed thermally in the mixed solvent into sodium carbonate, which crystallized as stable, pure anhydrous soda. Fundamental mechanisms of this process are discussed: The stability of Trona as a function of mixed solvent composition, water activity and temperature is reported. The dissolution rate, the bicarbonate decomposition rate as well as the (pseudo) solid phase conversion rate of Trona were investigated as functions of mixed solvent composition and temperature. It was found that beyond a certain temperature, depending on the mixed solvent composition, the Trona would convert via the (pseudo) solid state.
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wet calcining of Trona sodium sesquicarbonate and bicarbonate in a mixed solvent
Journal of Crystal Growth, 2002Co-Authors: Robert S Gartner, G J WitkampAbstract:Abstract Trona ore is used in large amounts for the production of soda ash. A key step in this process is the conversion of Trona (sodium sesquicarbonate: Na 2 CO 3 ·NaHCO 3 ·2H 2 O) into soda (sodium carbonate anhydrate: Na 2 CO 3 ). Currently, this conversion is done industrially by calcining of the raw ore in rotary calciners at ca. 120°C or higher (Natural Soda Ash—Occurrences, Processing, and Use, Van Nostrand Reinhold, New York, 1991, p. 267). Trona can however be converted at lower temperatures by using a “wet calcining” technique. In this technique, Trona is contacted with an organic or mixed organic-aqueous solvent at a conversion temperature that depends on the water activity of the used solvent. In pure ethylene glycol this temperature can be as low as 55°C. The conversion by “wet calcining” occurs very similar to that in the regular dry calcining process via a solid phase conversion. The anhydrate crystals form directly from the solid Trona. This produces pseudomorphs (J. Chem. Eng. Data 8(3) (1963) 301), i.e. agglomerates of fine anhydrate crystals (1–10 μm). At high temperatures, dense, finely pored agglomerates are formed, while the outer shape of the agglomerate retains the prism shape of the Trona crystal. At low conversion temperatures, loosely packed or even unstable agglomerates are found.
