Ettringite precipitation

Ettringite and s-AFm were independently prepared by precipitation from stoichiometric mixtures of C3A, gypsum and water, following the reported methods [29]. of the dissolved sulfate leads to the reaction of ettringite with tricalcium aluminate, sults of a simulated sulfate attack revealed that ettringite precipitated upon Sulphate removal from mine water by precipitation as ettringite by newly developed electrochemical aluminium dosing method. Emma-Tuulia Nurmesniemi* 18 Jan 2021 The precipitation pathway is based on the formation of two main minerals ( ettringite and barite). It can lead to total sulfate removal but can also 19 Aug 1999 added after standard lime treatment to precipitate a compound called ettringite, which can be removed using a clarifier and filter press. Sulfate others like calcium hydroxide and ettringite can precipitate in the water phase.

The aim of this research was to investigate sulphate removal from mine water by precipitation as ettringite (Ca6Al2(SO4)3(OH)12·26H2O) and the utilisation of the precipitate as a sorbent for arsenate removal. The mine water sulphate concentration was reduced by 85-90% from the initial 1400 mg/L during ettringite precipitation depending on the treatment method. The precipitation conditions Chemical, physical and biological technologies for removal of sulphate from mine tailings pond water (8 g SO 4 2-/L) were investigated. Sulphate concentrations of approximately 1,400, 700, 350 and 20 mg/L were obtained using gypsum precipitation, and ettringite precipitation, biological sulphate reduction or reverse osmosis (RO) after gypsum pre-treatment, respectively.

In the present study, experiments were conducted to optimize sulfate removal efficiency with ettringite precipitation from landfill leachate using Response Surface Methodology (RSM) and Central Composite Design (CCD). The statistical analysis of the results showed that the operating parameters such as molar rates of Ca/ SO4 and Al/SO4, and pH had a significant effect on sulfate removal efficiency. Ettringite was precipitated in the presence of TcO4-, IO3-, and/or CrO42-, known contaminants of concern to nuclear waste treatment, over pre-determined precipitation periods.

Effects of solid to liquid ratios, pH and temperature on ettringite dissolution, Al recovery and transformation of precipitates were investigated by batch experiments. In this study, the principles of chemical precipitation of sulfate which is based on the formation of ettringite, a double salt with the formula Ca3Al2O6.3CaSO (4).32H (2)O are evaluated.

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Any in SPE Disciplines (1) Conference. Abu Dhabi International With regard to the precipitation rate of ettringite from solution (stage 3), Baur et al. 22) measured the dissolutionprecipitation reaction rate between the solid ettringite and the aqueous • Ettringite precipitation ( SAVMIN™) • Aluminum added to water to form ettringite (calcium aluminum sulfate, Ca₆Al₂(SO₄)₃(OH)₁₂·26H₂O • Reaction at pH 11 -13 • Feasible for SO 4 < ~ 1,800 mg/l (gypsum solubility) • Sulfate removal to ~ 10’s mg/l - 000’s mg/l SO 4 • Aluminum form can be: Se hela listan på hindawi.com Abstract In the present study, experiments were conducted to optimize sulfate removal efficiency with ettringite precipitation from landfill leachate using The optimum pH for ettringite precipitation in all systems was found to be around 12.0. By the application of the method, 0.06 M initial sulphate concentration was reduced down to 60 mg/L for ettringite precipitation. The pilot plant was supplied by G.U.N.T. Gerätebau GmbH. A photograph of the plant in use with NaAlO 2 and lime and a close-up of the ettringite precipitates can be seen in Figures 1 and 2.
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Boron, fluoride and up to 30 percent of the chloride and nitrate in water have also been removed. The optimum pH for ettringite precipitation in all systems was found to be around 12.0. 2020-01-01 · In Portland cements, most of ettringite is formed by the hydration of tricalcium aluminate Ca 3 Al 2 O 6 (C 3 A in cementitious notation) with calcium sulfate that is the result of dissolution-precipitation processes. Solid reactants dissolve and hydrate compounds precipitate from the released ions.

In the present study, ettringite precipitation was theoretically and experimentally evaluated as a means of sulphate removal. The results showed that ettringite precipitation is an effective and In the present study, ettringite precipitation was theoretically and experimentally evaluated as a means of sulphate removal. The results showed that ettringite precipitation is an effective and reliable method for sulphate removal. Synthetically prepared samples which were simulated to total wastewaters originating from the textile industry (sulphate concentration of 0.06 M) and to dye bath effluent (sulphate concentration of 0.22 M) were subjected to ettringite precipitation using the Ettringite decomposition is the reverse of ettringite formation and forms the gibbsite for recycle.
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Gerätebau GmbH. A photograph of the plant in use with NaAlO 2 and lime and a close-up of the ettringite precipitates can be seen in Figures 1 and 2. The plant consists essentially of a raw water tank, a reactor tank followed by a (2016).

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- Gypsum (CSH2) is added to the clinker. Water is added to make hydrated paste. 27 Jul 2017 This project was created with Explain Everything™ Interactive Whiteboard for iPad. 12 Aug 2017 The line connecting the points of equal rainfall magnitude in a catchment are known as ISOHYETS.