Calcium sulfate whisker one-step preparation using semi …
The results demonstrate that the presence of calcium carbonate inhibits high-efficiency desulfurization ash oxidation at low temperatures and affects calcium sulfate whiskers growth. ... Liu et al. (2016) studied the effects of desulfurized gypsum particle size, slurry concentration, and ... The use of glacial acetic acid to remove CaCO 3 in ...
FGD-Gypsum Waste to Capture CO2 and to Recycle in …
Calcium carbonate has been used as a mineral filler in gypsum panels, ... The desulfurized gypsum (FGD) used in this research was provided by DGC units in Compostilla (G-C) (Ponferrada; Spain). A commercial gypsum (COMg) from the company AFIMOSA S.L. was also employed, in accordance with EN 13279-1 (CEN, 2009) standard .
A brief review on flue gas desulfurization gypsum recovery …
Newly developed carbonation technology toward CaCO 3 preparation also reveals a significant utilization way to recover high-value products from waste gypsum, whereas there is a shortage …
CN213865390U
The utility model relates to a system for with desulfurized gypsum preparation ammonium sulfate and calcium carbonate, include: the device comprises a first liquid storage tank, a second liquid storage tank, a first-stage reactor, a first-stage feeder, a three-step countercurrent washing equipment set A, a tail gas treatment tank, a second-stage reactor, a second-stage feeder, a …
Characterization and optimization of desulfurized construction gypsum
The carboxyl groups on the surface of the nanocellulose may also interact with the calcium ions in the gypsum matrix, promoting the formation of calcium sulfate dihydrate crystals [29]. The mechanical strength of the FGD gypsum-nanocellulose composites was evaluated by measuring the flexural and compressive strength at different curing ages.
Recent advances in flue gas desulfurization gypsum …
The main component of this gypsum is calcium sulfate dihydrate, which also contains calcium carbonate, calcium sulfite and other impurities (Koralegedara et al., 2019b). As the demand for environmental protection increases, the output of FGD gypsum has increased worldwide, especially in the European Union and China.
Utilization of low-quality desulfurized ash from semi-dry …
The annual production of desulfurized ash from newly added by-products in China is approximately 15 million tons, and it will accumulatively reach several billion tons by 2020 approximately [13], [14], [15]. It usually contains calcium sulfite, dihydrate gypsum, calcium carbonate and unreacted calcium hydroxide [7].
Emission reduction process for dechlorinating flue‐gas …
According to the ACAA (American Coal Ash Association), 1 chloride content in the desulfurized gypsum should be reduced to below 400 ppm.
Elemental sulfur recovery from FGD gypsum and calcium …
Flue gas desulfurization (FGD) gypsum mainly contains gypsum, which comes from the FGD by using lime or limestone. The effects of calcining temperature and time on …
TWI670229B
The invention relates to a method for separating calcium sulfate and calcium carbonate from desulfurization gypsum waste (or by-product lime) containing calcium oxide, calcium carbonate and calcium sulfate produced in a process for desulfurization of flue gas. The main purpose is to first pulverize the waste and mix it with water to form a suspension, and then react and heat …
A novel resource utilization of the calcium-based semi-dry …
In the calcium-based semi-dry FGD process, hydrated lime is generally used as SO 2 sorbent in the form of slurry, and the lime slurry is sprayed into a spray scrubbers. The sprayed droplets simultaneously evaporate and react with SO 2 to form calcium sulfite, as well as the CO 2 is also neutralized by lime droplets to form calcium carbonate. Then, the deactivated sorbent is …
Is All Gypsum Created Equal?
FGD gypsum is very similar to mined gypsum, but carries slightly more calcium carbonate into the final byproduct and is a bit lower on sulfur content as a result.
Nonpolar Surface Modification Using Fatty Acids and Its …
fixation, this desulfurized gypsum is reacted with ammonia under a flow of carbon dioxide or with ammonium carbonate ((NH 4 ) 2 CO 3 ) obtained from the reaction between carbon dioxide and ammonia, producing ammonium sulfate ((NH 4 ) 2 SO 4 ) and the calcite forms of CaCO 3 as the main products [20].
Recent advances in flue gas desulfurization gypsum …
Synthetic dyes, used in several industries, are prevalent water contaminants. The use of gypsum to remove Basic Red 46, a common dye used in ... asphalt, carbonate-products, calcium sulfate-hemihydrate, and other construction materials. ... growth and yield using desulfurized gypsum in the west of Songnen Plain, northeast China. Geoderma, 187 ...
Nonpolar Surface Modification Using Fatty Acids and Its …
CaCO3 is often used as an additive in many industries. However, additional functions are required to expand its applicability. This entails modification of its physicochemical properties. Accordingly, in this study, a particle surface modification treatment was performed on CaCO3 produced from desulfurized gypsum for a range of industrial applications. In the experiment, fatty acids were …
Carbonation test of dry desulfurized gypsum.
Coupled gypsum dissolution-calcium carbonate precipitation experiments were performed in closed system reactors and in the presence of either aqueous 0.1 M Na2CO3, 0.1 M NaHCO3 or 0.1 M Na2CO3 + 0 ...
(PDF) The Key Application Technology of …
The results show that ad ding desulfurized gypsum, ... carbonate, calcium sulfite, an d soluble salts composed of . ... remove the mold after 24 hours, and cure it in .
A novel resource utilization of the calcium-based semi-dry …
Semantic Scholar extracted view of "A novel resource utilization of the calcium-based semi-dry flue gas desulfurization ash: As a reductant to remove chromium and vanadium from vanadium industrial wastewater." by D. Fang et al. ... The removal of high concentration flue gas sulfur dioxide (SO2) using manganese carbonate ore desulfurization (MCO ...
Steering the early strength of clinker-free cementitious …
The binders used in this study included granulated blast furnace slag (GBFS), steel slag (SS) and desulfurized gypsum (DG). Wet DG was provided by a thermal power plant, SS and GBFS were provided by a steel smelting facility in Shanxi province. ... it mainly reacted with calcium hydroxide in the slurry, and formed insoluble calcium carbonate or ...
A brief review on flue gas desulfurization gypsum recovery …
Newly developed technology can transform FGDG into calcium carbonate while capturing CO 2 in the flue gas. The development of FGDG carbonation can recover Ca and S resources and contribute to the circular economy. 1. Introduction. Finally, FGDG is produced from the …
Potential of desulfurized gypsum as a sulfate alternative in …
Desulfurized gypsum (DG) presents significant challenges in recycling with the rapid development of industrialization. To explore the feasibility of DG as a sulfate source in producing limestone calcined clay cement (LC3), this study investigates the differences between LC3 samples containing DG and those containing natural gypsum (NG) in terms of hydration, …
How to Remove Calcium from Water – Fresh Water Systems
Calcium in water refers to calcium ions dissolved in water as it flows through or over calcium-rich materials, like limestone, chalk, and gypsum. As water moves through soil and rocks, it dissolves minerals like calcium carbonate or calcium sulfate, which are abundant in many geological formations.
Progress in the Preparation of Calcium Carbonate by …
To avoid the long-term pollution of land and water by industrial gypsum by-products, the exploitation of this resource has become a priority. The indirect synthesis of calcium carbonate from the industrial by-product gypsum has received substantial attention as a viable method for resource utilization. Currently, the primary problems in the indirect manufacture of …
Utilization of low-quality desulfurized ash from semi …
Desulfurized ash contains about 21.33% hemihydrate calcium sulfite, 18.11% calcium carbonate, 28.55% dihydrate gypsum, 25.81% calcium hydroxide, 1.85% calcium oxide. Particle size distributions of hemi-hydrate gypsum and desulfurized ash are given in Fig. 1 A. The specific surface areas of desulfurized ash and hemihydrate gypsum are 351 and
Desulfurization gypsum uses and properties
Desulfurization gypsum, also known as FGD gypsum (flue gas desulfurization gypsum), is an industrial by-product gypsum obtained by desulfurization and purification of flue gas generated …
The Key Application Technology of Desulfurized …
particle size. Since desulfurized gypsum contains water with a mass fraction of about 10%, it also contains impurities such as fly ash, organic carbon, calcium carbonate, calcium sulfite, and soluble salts composed of sodium, potassium, magnesium sulphate or chloride. Therefore, the application of desulfurized gypsum is
Desulphurisation
The SO 2 is washed out with water oxidized to sulfates, SO 3, in the aqueous solution, and precipitated with calcium from the limestone/quicklime into dihydrous calcium sulfate (CaSO 4 ·2H 2 O) gypsum. The gypsum crystals are separated out of the suspension as a moist, fine crystalline powder with the aid of centrifuges or filters.
Flue Gas Desulfurization Gypsum
The semi-hydrate content of desulfurized gypsum is adjusted as a natural plaster substitute for producing gypsum board, wallboard [107].The modified treatment of desulfurized gypsum with cement, inorganic waste, straw fiber and other wastes can be used to manufacture high-insulation and compression-resistant wall materials [108].Desulfurized gypsum is incorporated into the …
CO2 mineralization of carbide slag for the production of light calcium …
Three stage washing was adopted for CaCO 3 to remove the ions carried in calcium carbonate. The washing water was used for ammonia capture in the mineralization section. ... Nonpolar surface modification using fatty acids and its effect on calcite from mineral carbonation of desulfurized gypsum. Coatings, 8 (1) (2018), p. 43. Crossref View in ...
(PDF) Carbonate and Gypsum
The carbonate minerals and gypsum exert a dominating influence on soils inwhich they are present because of their relatively high solubility, and in the caseof the carbonates, their alkalinity and ...