ettringite precipitation Source. OnePetro (1) Date. 2020 (1) to. Go SPE Disciplines. Highlight matches. Any in SPE Disciplines (1) Conference. Abu Dhabi International

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. The Al-2

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 Ettringite precipitation based on formation of sulphate salts with low solubility can be used as a pretreatment method to overcome sulfate inhibition in anaerobic process. Calcium alumina-sulfate is commonly used to identify ettringite mineral. The following equation shows the basic chemical reaction to form ettringite Eq (1):) 1 ( A novel sulfate removal process via ettringite precipitation was developed by dissolving ettringite and recycling Al3+ under low pH condition. Effects of solid to liquid ratios, pH and temperature on ettringite dissolution, Al recovery and transformation of precipitates were investigated by batch experiments. The optimum condition for Al recovery is pH =3.0, suspended solid of 9.8 g/L and The ettringite process flow diagram used for simulation is illustrated in Figure 3. The process has three principal processing stages followed by a pH adjustment step.

Ettringite precipitation

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. The formation of ettringite as a precipitate is another technique that can be used to treat mine-impacted water and has the capability of achieving sulphate concentrations that adhere to potable water and effluent discharge guidelines. Ettringite represents a group of acicular calcium aluminate hydrates (Damons and Petersen, 2002). Ettringite precipitation based on formation of sulphate salts with low solubility can be used as a pretreatment method to overcome sulfate inhibition in anaerobic process. Calcium alumina-sulfate is commonly used to identify ettringite mineral.

11 Sep 2015 In addition to work on ettringite precipitation, previous work has probed the role of gypsum formation and found that its precipitation also leads

Go SPE Disciplines. Highlight matches. Any in SPE Disciplines (1) Conference. Abu Dhabi International With regard to the precipitation rate of ettringite from solution (stage 3), Baur et al.

Sulphate precipitation as ettringite is a modification of high pH lime precipitation (Geldenhuys et al., 2003, Tolonen et al., 2015). With precipitation as ettringite, mine water sulphate concentration can be reduced to less than 200 mg/L. This is less than the drinking water guideline in Finland, which is 250 mg/L sulphate (Directive 98/83/EC). When ettringite precipitation is used for waters with high sulphate concentration (>3000 mg/L), it may be economical to use traditional lime

The experimental study of the CaO-SiO2-Al2O 3-SO3-H2O system clarified the Sulphate removal from mine water by precipitation as ettringite by newly developed electrochemical aluminium dosing method. Emma-Tuulia Nurmesniemi* mental results reveal that citric acid works as an inhibitor of ettringite's formation leading to the precipitation of monosulfate and gypsum; the ettringite surface Sulphate concentrations of approximately 1,400, 700, 350 and 20 mg/L were obtained using gypsum precipitation, and ettringite precipitation, biological In excess of 95% of the Se and B in solutions spiked with various concentrations of these elements has been removed by precipitation of ettringite. Ettringites The evaluation of chemical precipitation for sulfate removal such as gypsum and ettringite formation as well as the use of membrane filtration and the decision others like calcium hydroxide and ettringite can precipitate in the water phase. The first step of reaction is the dissolution of sulphate and alkali constituents, The SAVMIN method consists of the removal of sulphates by precipitation of ettringite. This is achieved by reaction of aluminium hydroxide with the sulphate ion Delayed ettringite formation (DEF) in concrete causes internal swelling, which reduces the mechanical properties aggregate, suggesting ettringite precipitation. binder (CAC+Sulfate) .There is still some aluminium ions in the solution and ettringite precipitation is strongly accelerated due to the large impact of the calcium. Ettringite precipitation consumes calcium, aluminium and sulfate ions which causes further C3A and gypsum dissolution.

By the application of the method, 0.06 M initial sulphate concentration was reduced down to 60 mg/L for Ettringite Cements Its Potential. Mineral can put concrete shoes on rad contaminant. Tim Ledbetter, PNNL.
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et al., 1996). This precipitation process is well-understood, reliable and can be easily controlled.

It is surprising to find that products based on crystalline aluminium hydroxide (Hydrargillite), even at relatively high doses, are not appropriate for ettringite precipitation. The obvious 2020-08-01 · Ettringite precipitation was implemented as an alternative to lime precipitation to process sulfate-rich brine resulting from the NF operation. More than 93% of the sulfate ions were removed by ettringite precipitation, whereas lime precipitation removed less than 28% under the same conditions due to the difference in their solubility.
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Chemical precipitation. Elina Merta, VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Finland, elina.merta (at)vtt.fi. Chemical precipitation techniques can be used to solve a number of problems in mine water treatment. Precipitation and co-precipitation are applicable for the removal of metals as hydroxides

Mineral can put concrete shoes on rad contaminant. Tim Ledbetter, PNNL.

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27 Jul 2017 This project was created with Explain Everything™ Interactive Whiteboard for iPad.

Sulphide precipitation; Precipitation with barium salts; Ettringite precipitation; Iron co-precipitation; Ion exchange; Membrane processes; Sulphate reduction in reactors; Treatment/disposal of water treatment residues; Passive treatment technologies. Aerobic constructed wetlands; Anaerobic constructed compost wetlands 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.

Environmental Technology 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.

Ettringite formation can also provide a polishing effect, allowing precipitation of metals and metalloids such as Ni, Cd, Cu, Zn, Cr, As, Se, and Cd. Sulphate precipitation as ettringite is a modification of high pH lime precipitation (Geldenhuys et al., 2003, Tolonen et al., 2015). With precipitation as ettringite, mine water sulphate concentration can be reduced to less than 200 mg/L. This is less than the drinking water guideline in Finland, which is 250 mg/L sulphate (Directive 98/83/EC). When ettringite precipitation is used for waters with high sulphate concentration (>3000 mg/L), it may be economical to use traditional lime A novel sulfate removal process via ettringite precipitation was developed by dissolving ettringite and recycling Al 3+ under low pH condition. 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. The Al-2 ettringite precipitation is a well-known process and can be described as a standard method for sulphate removal from industrial wastewater at relatively small flow (S.

STATISTICAL OPTIMIZATION OF ETTRINGITE PRECIPITATION IN LANDFILL LEACHATE @article{Aygun2018STATISTICALOO, title={STATISTICAL OPTIMIZATION OF ETTRINGITE PRECIPITATION IN LANDFILL LEACHATE}, author={A. Aygun and S. Dogan and M. E. Argun}, journal={Brazilian Journal of Chemical Engineering}, year={2018}, volume={35}, pages={969-976} } 2000-02-28 · ettringite could reduce the protection the air void system affords against freeze-thaw damage (see discussion of freeze-thaw resistance below). Ettringite formed by dissolution and recrystallization in void spaces and cracks is often referred to as “secondary ettringite.” Secondary ettringite is not detrimental to concrete performance. the ettringite precipitation is a recognised method, appropriate to be implemented After each phase pH, EC and sulphate concentrations in industrial water treatment facilities.