Experimental study of <scp>CaS</scp> preparation from lignite‐reduced phosphogypsum in a fluidized bed

Ma, Dong; Wang, Qinhui

doi:10.1002/jctb.7285

Cited by 16 publications

(10 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is mainly because when the C/S molar ratio is to the sulfide residues in the slag, thereby reducing the desulfurization rate of the system. 51,52 In summary, it can be concluded that the amount of reducing agent and smelting temperature are the key factors affecting the desulfurization effect and slag phase structure in the new process of acid-making and slag wool production based on phosphogypsum. It was appropriate to add the reductant with a C/S molar ratio of 0.5−0.8, which was consistent with the previous research results.…”

Section: Resultsmentioning

confidence: 99%

Process Optimization and Mechanism Study for Sulfur Recovery from High-Silica Phosphogypsum via Carbothermal Reduction Smelting

Wang,

Hou,

et al. 2024

ACS Omega

View full text Add to dashboard Cite

Phosphogypsum produced from wet-processed phosphoric acid mainly consists of calcium sulfate dihydrate, which is an important sulfur resource. The traditional sulfuric acid and cement process based on phosphogypsum suffers from unstable cement quality owing to impurities such as phosphorus and fluorine and kiln ringing caused by the low-melting phase. This study investigated sulfur recovery and value-added utilization of liquid slag from high-silica phosphogypsum via carbothermal reduction smelting. A phosphogypsum ingredient (PGI) system was constructed by adding appropriate amounts of silica, alumina, magnesium oxides, and iron oxides to meet the production requirements of slag wool. Carbothermal reduction smelting experiments suggested that the temperature and C/S molar ratio significantly affected the desulfurization rate and phase structure of the slag. More than 97.44 wt % of sulfur could be recovered with a C/S molar ratio of 0.5−0.8 at 1300 °C or above in the molten state, and the molten slag was an amorphous magnesium−calcium−aluminosilicate. The PGI desulfurization mechanism is discussed based on the phase transformation and slag microstructure evolution.

show abstract

Section: Resultsmentioning

confidence: 99%

Process Optimization and Mechanism Study for Sulfur Recovery from High-Silica Phosphogypsum via Carbothermal Reduction Smelting

Wang,

Hou,

et al. 2024

ACS Omega

View full text Add to dashboard Cite

show abstract

“…The work [ 13 ] proposed a simple and efficient approach for the high-purity CaSO 4 ·2H 2 O (DH) whiskers and α-CaSO 4 ·0.5H 2 O (α-HH) whiskers derived from phosphogypsum (PG). The work [ 14 ] studied the effect of different conditions on the preparation of CaS by reducing PG with coal in a fluidized bed. This method not only requires a large initial investment, but also forms new pollutants and faces environmental pollution problems.…”

Section: Introductionmentioning

confidence: 99%

Study on the Mechanical Properties of Cast-In-Situ Phosphogypsum as Building Material for Structural Walls

et al. 2023

View full text Add to dashboard Cite

The application of cast-in-situ phosphogypsum as the wall material of building structures can greatly reduce the environmental pollution caused by phosphogypsum. Through the uniaxial compression test of cast-in-situ phosphogypsum specimens, the compressive strength of cast-in-situ phosphogypsum is determined, the constitutive relationship of the material is drawn up, and the elastic modulus and Poisson’s ratio of the material are determined. The results show that when the strain of the specimen is close to the peak strain, the cast-in-situ phosphogypsum has brittle properties and rapidly fails, where the failure state is mainly splitting failure. The retarder has a great influence on the peak stress. When the content of the retarder is about 0.3%, the peak stress is 8.6 MPa and the ultimate strain is 2.54 × 10−3, while the peak stress is 2.8 MPa and the ultimate strain is 2.01 × 10−3. The three segment constitutive fitted equations reflect all the characteristics of the compression specimen. When the strength of the cast-in-situ phosphogypsum is high, the elastic modulus is also high. When the content of the retarder is about 0.3%, the elastic modulus is 5300 MPa, and when the content of retarder is far greater than 0.3%, the elastic modulus is 2000 MPa. The Poisson’s ratio of material is recommended as 0.19.

show abstract

“…In addition, compared with traditional limestone calcination, CO 2 emissions are significantly reduced. While CaSO 4 decomposes at temperatures of up to 1400 °C, introducing reducing agents can drastically lower this temperature 6 . Common reducing agents mainly include carbon‐based (lignite, 7 anthracite, 8 coke, 9 coal gangue, 10 CO 11 ) and sulfur‐based (sulfur, 12 pyrite, 13 H 2 S 14 ).…”

Section: Introductionmentioning

confidence: 99%

“…While CaSO 4 decomposes at temperatures of up to 1400 °C, introducing reducing agents can drastically lower this temperature. 6 Common reducing agents mainly include carbon-based (lignite, 7 anthracite, 8 coke, 9 coal gangue, 10 CO 11 ) and sulfur-based (sulfur, 12 pyrite, 13 H 2 S 14 ). Therefore, the conversion of CaSO 4 to CaO is completely feasible in terms of process.…”

Section: Introductionmentioning

confidence: 99%

Experimental study on preparation of calcium oxide by coal reduction of calcium sulfate in carbon dioxide atmosphere

Wang

2023

J of Chemical Tech & Biotech

Self Cite

View full text Add to dashboard Cite

BACKGROUND: Recent studies show that CaO is being produced from CaSO 4 by CO reduction using fixed-bed reactors. However, the product yield is low and the reaction time is long. Furthermore, the high cost of CO hinders its application in industrial processes. Therefore, a new process is proposed for preparing CaO by CaSO 4 decomposition using lignite under CO 2 . The influence of various process conditions on the production of CaO by CaSO 4 decomposition is investigated by combining kinetic and FactSage simulations. Finally, a typical industrial gypsumphosphogypsum (PG)is used for experimental verification.RESULTS: The study found that adding CO 2 during the coal reduction of CaSO 4 increases the CaO yield. The ideal conditions are 1.75 C/Ca molar ratio, 7.5% CO 2 concentration at 1100 °C with the maximum CaSO 4 decomposition rate and CaO yield of 99.63% and 99.28%, respectively. CaO generation is carried out using a two-step process. Initially, CaSO 4 is reduced to become CaS and CaO, and CaS interacts with CaSO 4 to produce CaO. Secondly, the reaction between CaS and CO 2 produces CaO. The nucleation and growth model with g(⊍) = −ln(1 − ⊍) is applicable to both processes. The experimental use of PG confirms the above conclusions, but SiO 2 in PG reacts with CaO to produce Ca 2 SiO 4 and affect the CaO yield.CONCLUSION: The addition of CO 2 promotes the conversion process of CaSO 4 to CaO. Increasing the temperature, C/Ca molar ratio and CO 2 concentration favor the decomposition of CaSO 4 into CaO. This study offers advice for using CaSO 4 products like PG as resources.

show abstract

Experimental study of CaS preparation from lignite‐reduced phosphogypsum in a fluidized bed

Cited by 16 publications

References 31 publications

Process Optimization and Mechanism Study for Sulfur Recovery from High-Silica Phosphogypsum via Carbothermal Reduction Smelting

Process Optimization and Mechanism Study for Sulfur Recovery from High-Silica Phosphogypsum via Carbothermal Reduction Smelting

Study on the Mechanical Properties of Cast-In-Situ Phosphogypsum as Building Material for Structural Walls

Experimental study on preparation of calcium oxide by coal reduction of calcium sulfate in carbon dioxide atmosphere

Contact Info

Product

Resources

About