Next Article in Journal
Census-Based Variables Are Informative about Subjective Neighborhood Relations, but Only When Adjusted for Residents’ Neighborhood Conceptions
Previous Article in Journal
Global Mangrove Deforestation and Its Interacting Social-Ecological Drivers: A Systematic Review and Synthesis
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Sustainability
Volume 14
Issue 8
10.3390/su14084436
sustainability-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Technical Note

Recycling of Industrial Waste Gypsum Using Mineral Carbonation

by
Chan-Ung Kang
1,
Sang-Woo Ji
2 and
Hwanju Jo
1,*
1
Climate Change Response Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 124, Gwahak-ro, Yuseong-gu, Daejeon 34132, Korea
2
Policy & Planning Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 124, Gwahak-ro, Yuseong-gu, Daejeon 34132, Korea
*
Author to whom correspondence should be addressed.
Sustainability 2022, 14(8), 4436; https://doi.org/10.3390/su14084436
Submission received: 15 February 2022 / Revised: 4 April 2022 / Accepted: 6 April 2022 / Published: 8 April 2022
(This article belongs to the Topic Carbon Capture, Storage and Utilisation Technologies (CCS/CCU))
Browse Figures
Review Reports Versions Notes

Abstract

:
Direct mineral carbonation (MC) is used to mitigate carbon dioxide (CO2) emissions. This method has the great advantages of reducing the amount of industrial residues and creating valuable materials by incorporating CO2. Waste gypsum, industrial waste including flue gas desulfurization (FGD) gypsum (25.27–53.40 wt% of CaO), and phosphogypsum (30.50–39.06 wt% of CaO) can be used for direct MC (conversion rate up to 96%). Mineral carbonation converts waste gypsum into calcium carbonate (CaCO3), which can be recycled during desulfurization. Furthermore, ammonium sulfate ((NH4)2SO4), which is used as a fertilizer, can be prepared as a by-product when the carbonation reaction is performed using ammonia (NH3) as a base. In this study, recent progress in the carbonation kinetics and preparation of CaCO3 using FGD gypsum and phosphogypsum with NH3 was investigated. Temperature, CO2 partial pressure, CO2 flow rate, and NH3 concentration were reviewed as factors affecting carbonation kinetics and efficiency. The factors influencing the polymorphs of the prepared CaCO3 were also reviewed and summarized. A state-of-the-art bench-scale plant study was also proposed. In addition, economic feasibility was investigated based on a bench-scale study to analyze the future applicability of this technology.

1. Introduction

Mineral carbonation (MC) plays an important role in carbon dioxide (CO2) storage. Most MC technological developments are still focused on ex situ process concepts. Since the 1990s, scientists have begun fundamental research on MC using peridotite to accelerate natural processes [1]. Recently, several studies using byproducts have been reported. The ability of MC with industrial waste is limited and much less than that of MC with silicate minerals [2,3]. However, studies on MC with industrial waste have reported positive results. Most industrial wastes can acquire acceptable MC efficiencies under mild conditions [4]. Industrial wastes containing divalent metals generally have a higher chemical reactivity, in addition to the requirement that the problem of industrial waste be treated as waste [4]. Therefore, MC from industrial waste addresses waste problems and achieves acceptable CO2 conversion under mild conditions [3,5]. Industrial waste can come from various sources such as coal fly ash [6,7,8], metallurgical slag [9,10], waste concrete [11,12], mine waste [13,14], and industrial waste gypsum [15,16].
Waste gypsum, among the industrial wastes, has a high calcium (Ca) content; therefore, it has good evaluation potential for CO2 capture. In the case of flue gas desulfurization (FGD) gypsum, the flue gas of the power plant can be used directly, and desulfurized gypsum, the starting material, can be continuously supplied. This eliminates the cost of CO2 capture, transportation, and raw materials. In addition, both calcium carbonate (CaCO3) and ammonium sulfate ((NH4)2SO4) generated after the reaction can be commercialized for use as CaCO3 for desulfurization and fertilizers (Figure 1). Phosphogypsum, generated by reacting sulfuric acid and phosphate rock to produce phosphoric acid [17], also has potential for MC. The annual production of FGD gypsum and phosphogypsum exceeds 140 million tons [18,19] and 280 million tons [20], respectively. If the total amounts of FGD gypsum and phosphogypsum were used to sequester CO2 through MC, almost 100 million tons of CO2 would be stored annually.
Waste FGD gypsum and phosphogypsum usually take the form of calcium sulfate dihydrate (CaSO4·2H2O). Thus, these gypsums can be used to produce CaCO3 through direct carbonation by injecting CO2 gas into a suspension of waste gypsum and ammonia (NH3) solution [23,24]. Ammonium hydroxide (NH4OH) is used to enhance the MC effect. As NH4OH is a readily available basic source for many industrial processes, the utilization of NH4OH is attractive from an environmental point of view [25].
The prepared CaCO3 using byproduct gypsum as a raw material not only realizes the resource utilization of byproduct gypsum, but also saves the natural resources of CaCO3. Furthermore, in the direct carbonation of by-product gypsum, a highly pure sulfate salt can be obtained through crystallization using the difference in solubility with CaCO3 (Equation (1)) [26,27]. A stoichiometric excess NH3 and CO2 react to form an ammonium compound. The decomposition temperature of these ammonium compounds is 60 °C or less, which can be easily recovered during the crystallization process of ((NH4)2SO4) aqueous solutions.
CaSO4·2H2O(s) + CO2(g) + 2NH4OH(aq) → (NH4)2SO4(aq) + CaCO3(s) + 2H2O
Several researchers have recently reported developments in this field. Parameters affecting direct aqueous MC and indirect aqueous MC using industrial byproduct gypsum, including FGD gypsum, phosphogypsum, and red gypsum, have been analyzed by Wang et al. [25]. An analysis of the scale-up applications of MC using industrial solid waste was also reported by Liu et al. [28].
The technology of MC using waste gypsum has been advanced through several lab scale studies. However, there have been limited discussions on bench-scale studies of MC by reacting flue gas and NH3 with waste gypsum, and a detailed economic analysis has not been reported. This makes comparison with other MC technologies difficult and does not guarantee field applicability of this technology.
This study focused on direct aqueous carbonation using waste gypsum with NH3. The state-of-the-art bench-scale plant studies were discussed to confirm the potential for scale-up of the technology; in particular, economic feasibility based on the bench-scale studies was investigated to analyze the future applicability of this technology. Furthermore, recent progress in the carbonation performance of two types of byproduct gypsum, FGD gypsum and phosphogypsum, was discussed based on CO2 carbonation efficiency. The factors influencing the carbonation kinetics and preparation of CaCO3 were reviewed.

2. Characterization of Waste Gypsum

The compositions of FGD gypsum and phosphogypsum were analyzed. From the results shown in Table 1 and Table 2, waste gypsum from different sources differs with respect to its constituents. The main components of the FGD gypsum are sulfur trioxide (SO3), calcium oxide (CaO), and bound water, and the main impurities are silicon dioxide (SiO2), aluminum oxide (Al2O3), and ferric oxide (Fe2O3). The composition of phosphogypsum production depends on the quality of the phosphate rock used to produce phosphoric acid (H3PO4) and the processing route [29].
The major constituents of phosphogypsum are similar to those of FGD gypsum, but contain more impurities such as SiO2, free H3PO4, phosphates, and organic matter [30]. The sulfur content of FGD gypsum and phosphogypsum was 12.54–22.39 wt% and 12.40–22.80 wt%, respectively, showing similar ranges. However, the different Ca content ranges indicated the difference between these two waste gypsums. FGD gypsum has a wide range (standard deviation 5.55 wt%) with Ca 18.06–38.16 wt%, whereas phosphogypsum has a narrow range (standard deviation 2.15 wt%) with 21.80–27.92 wt% Ca. FGD gypsum is generated during the desulfurization process of flue gas and, as CaCO3 added in a large amount stoichiometrically remains unreacted, the Ca content is higher than the S content. The moisture contents of FGD gypsum and phosphogypsum are usually in the range of 1–23% and 8–30% [31], respectively.

3. Mineral Carbonation of Byproduct Gypsum

3.1. Carbonation Kinetics and Preparation of CaCO3

Several factors influence the carbonation kinetics and preparation of CaCO3. Herein, these factors, including temperature, NH3 concentration, solid–liquid ratio, CO2 flow rate, CO2 partial pressure, induction period, kinetics, and preparation of CaCO3 are discussed.

3.1.1. Temperature

Gypsum carbonation is a highly exothermic reaction that rapidly increases the temperature of the reaction slurry in a short time. As gypsum carbonization is an exothermic process, high temperatures are undesirable for carrying out carbonization from a thermodynamic point of view. However, the temperature can affect the rate of carbonation. The conversion of gypsum to CaCO3 increases with elevated temperatures. A study showed that carbonation of FGD gypsum at 40 °C was nearly twice as fast as that at room temperature [41]. FGD gypsum conversion was close to 90% at 40 °C after 1 h, according to the results of another study, and the conversion reached up to 100% at a high temperature of 80 °C (Figure 2) [57].
However, studies have shown that the efficiency decreased gradually with increasing temperature due to the decrease in the solubility of CO2 and the decomposition of ammonium salts [41,58]. At ambient pressure, the carbonation conversion efficiency decreased with increasing temperature. The conversion efficiency of FDG gypsum carbonation at 40 °C (96%) was almost the same as at room temperature [41]. At temperatures above 60 °C, the efficiency was significantly lowered, and the carbonation conversion efficiency at 80 °C was approximately 20% lower than that at 40 °C [41]. This is the result of FGD gypsum not completely converted to CaCO3 owing to NH4OH loss at high temperatures of 60 °C and 80 °C [58]. However, below 40 °C, the temperature did not significantly affect the efficiency [41]. The conversion efficiency curves of phosphogypsum at 30 °C and 80 °C were shown to be similar with 4 bar and pure CO2 gas. However, the carbonation conversion efficiency of phosphogypsum increased slightly as the temperature increased from 30 °C to 80 °C when the pressure was increased to 8 bar [54].
Compared with phosphogypsum, FGD gypsum showed better reaction activity under normal conditions. It took approximately 30 min to achieve 90% conversion of FGD gypsum at 40 °C and less than 1 h for phosphorus gypsum at room temperature and atmospheric pressure [59].
The time required to reach reaction equilibrium is longer at low temperatures than at high temperatures [57]. Therefore, an appropriate temperature must be selected to balance the thermodynamics and kinetics of carbonation to achieve optimal CO2 sequestration efficiency.

3.1.2. CO2 Partial Pressure

Studies have found that efficiency may vary depending on the pressure because CO2 dissolution is the rate-determining step in direct carbonation [26,27]. At CO2 pressures higher than atmospheric conditions, more carbonate ions (CO32−) were produced, promoting carbonation. Furthermore, the high partial pressure of CO2 inhibits the decomposition of ammonium (bi)carbonate (NH4HCO3) when NH4OH is used as the basic medium [25].
Furthermore, despite the different initial temperatures (30 °C, 80 °C), the carbonation conversion ratio was similar at 0.4 MPa, but when the pressure was increased to 0.8 MPa, a temperature difference appeared. Accordingly, the phosphogypsum carbonation reaction rate is more sensitive to temperature at high pressure (0.8 MPa) than at low pressure (0.4 MPa) [54].
The carbonation conversion ratio increased significantly as the pressure increased from 0.4 MPa to 0.8 MPa (Figure 2). In addition, because a high carbonation rate reduces NH4OH loss, CO2 partial pressure has a significant effect on carbonation [54]. It was found that FGD gypsum achieved more than 90% carbonation conversion in 20 min at 60 mL/min at atmospheric pressure, whereas a comparable carbonation conversion (95%) for phosphogypsum required an increase in the CO2 pressure [54].
As CO2 dissolution and the dissociation of carbonic acid are rate-limiting steps in the aqueous carbonation process, the rate of the carbonation reaction can be strengthened by higher pressures [27,60]. However, increasing the pressure increases the cost, and an appropriate partial pressure must be used to enhance the MC.

3.1.3. CO2 Flow Rate

Theoretically, the total CO2 uptake should remain the same. However, at various CO2 flow rates, the calculated saturated CO2 uptakes at the inflection points of the curves were shown to be different. At a CO2 flow rate of 60 mL/min, the inflection point occurred at 20 min, when saturated CO2 sequestration had already been achieved. The total CO2 uptake, that is, the uptake capacity, can be attributed to the flow rate, inflection point time, and conversion rate. Therefore, carbonation efficiency increases with increasing flow rate and CO2 content [57]. Equilibrium was reached three times faster when the CO2 flow rate was 4 L/min than 1 L/min (Figure 3) [21]. When using 100 vol% CO2, more than 94% of the phosphogypsum was converted to calcium carbonate in approximately 30 min, whereas using 20 vol% CO2 required 90 min to achieve similar levels [61]. However, the CO2 sequestration efficiency did not always increase with the CO2 flow rate. The conversion increased slightly, but the time to reach reaction equilibrium became significantly shorter as the CO2 flow rate increased [62]. The optimal CO2 flow rate should therefore be selected based on CO2 storage efficiency, carbonation time, and product quality.

3.1.4. NH3 Concentration

NH3 can increase the carbonation rate and produce ((NH4)2SO4) as a byproduct of the carbonation process. The conversion efficiencies with NH3 have been reported to be higher than 95% at 10 min [21,54]. The carbonation efficiency of FGD gypsum was shown to increase with increasing NH4OH concentration, and the carbonation reaction was almost completed within 10 min [21]. Although stoichiometrically the molar ratio of OH−/Ca2+ is 2, NH4OH must be replenished because NH4OH can be lost during carbonation at temperatures above 60 °C. High conversion efficiency can be obtained by reacting with a molar ratio of OH−/Ca2+ of 2.1–3.6, higher than the stoichiometric ratio [26,57]. However, the excess ammonia ratio does not control the reaction rate (Figure 4) [54]. The study showed that at a very low NH3 content, the reaction equilibrium was reached within 10 min, but the FGD gypsum conversion was only 43% [57]. The FGD gypsum conversion rate rapidly improved with increasing NH3 content. In addition, it has been reported that an increase in the CO2 partial pressure and NH3 content is more favorable for carbonate ion formation through thermodynamic modeling of an electrolyte non-random two-liquid (NRTL) model of the NH3-CO2-H2O system [63].

3.2. Properties of CaCO3

Depending on the production conditions, CaCO3 prepared in the direct carbonation process of waste gypsum can form polymorphs of calcite, aragonite, and vaterite. A mixture of calcite and vaterite was observed during the production of the FGD gypsum-NH4OH-CO2 system [21]. Various factors, such as temperature, pH, and impurities, were shown to affect the properties of CaCO3 [64,65].
The carbonation temperature can significantly change CaCO3 polymorphs during gypsum carbonation. A study showed that calcite and vaterite peaks predominate at 20 °C and 40 °C, respectively. At 60 °C, the calcite peak was stronger than the vaterite peak. At 80 °C, an aragonite peak was observed without the vaterite peak [41].
A higher Ca2+/CO32−-ratio is a key factor in the formation of calcite [66,67]. Furthermore, it was shown that a rhombohedral form of calcite is formed when only a stoichiometric amount of NH4OH was used, whereas spherical vaterite is formed when NH4OH was used in excess [68]. However, the yield of pure rhombohedral calcite was relatively low (5%) under a short induction period [27]. A longer reaction time (>1 h) at 2 °C and an excess of CO2 (4.2 mol/mol Ca) favored the transformation of vaterite to rhombohedral calcite [69]. It was shown that injected CO2 also affects the formation of polymorph CaCO3 to the same extent as Ca2+ and NH4OH. For the phosphogypsum–NH4OH–CO2 system, direct carbonation with NH4OH under pure CO2 resulted in only calcite [54,70]. A mixture of calcite and vaterite was obtained in 20% CO2 [61].
The dolomite in gypsum is an important factor in the generation of CaCO3 polymorphs. The hydrophilicity and negative surface charge of dolomite particles has been shown to play an important role in the selective formation of calcite during FGD gypsum carbonation [34]. The carbonation product of FGD gypsum containing dolomite is a mixture of vaterite (60%) and calcite (40%), and only pure vaterite was obtained in the CaSO4·2H2O carbonation reaction that was performed [34].
Polymorphs of CaCO3 depend on the conditions of the carbonation system. Among the three polymorphs of CaCO3, calcite has the highest stability, whereas aragonite and vaterite are thermodynamically metastable and unstable, respectively [71]. To produce suitable polymorphs according to the utilization plan of the prepared CaCO3, further research on the difference in CaCO3 polymorphs during the carbonation of FGD gypsum and phosphogypsum is required.

4. Plant Study

As introduced in the previous section, many studies have proposed and tested strategies on a laboratory scale to overcome the main challenges of MC of waste gypsum. Scale-up studies have been performed on MC using other MC methods or waste materials. However, few efforts have been made to apply direct aqueous MC with NH3 using waste gypsum for scale-up applications.
A representative bench-scale plant study with continuous process was conducted from 2010 to 2015 by the Korea Institute of Geoscience and Mineral Resources (KIGAM) (Figure 5) [22]. Experiments were conducted by manufacturing a bench-scale continuous gypsum carbonation facility, and the reaction system consisted of a bubble column reactor (left of Figure 2) and CO2 and nitrogen (N2) injection facilities (right of Figure 2). The bubble column reactor increased the dissolution efficiency of CO2 such that the flue gas injected into the lower part of the slurry passed through the slurry and moved to the upper part. This study was conducted using FGD gypsum, which has a composition of 32.49 wt% CaO and 44.84 wt% SO3, generated in a thermal power plant, and was used as a raw material for carbonation without pretreatment to improve carbonation reactivity. A slurry with a solid–liquid ratio of 15 wt% containing 120 wt% NH3 based on a chemical equivalent was injected at a rate of 240 kg/h, and 15 vol% of CO2 was injected at a rate of 80 kg/h. Optimization was performed by operating a 1000 ton/year scale facility for 2000 h, resulting in a 97% carbonation rate and crystallization of ((NH4)2SO4).
KIGAM has been conducting empirical research at a scale of 2000 ton/year in with coal-fired power plants since 2021. To reduce CO2 and waste, further field studies beyond laboratory-based experimental and small-scale plant studies should be conducted. This will lead to precise process improvement.

5. Techno-Economic Analysis

Although MC has evolved through many previous studies, technology is not the only barrier against deployment; cost also acts as a barrier. Cost penalties are related to plant scale, operating conditions, and operating modulus, such as pre-treatment and/or post-treatment processes [72,73]. For direct carbonation, the energy requirement of the grinding process is the major cost of the overall process [74,75]. The power requirement is 352 MW, nearly 75% of which is the power required for ore grinding operations [74].
The economic feasibility of the carbonation method was analyzed based on the life cycle cost (LCC). LCC is an approach that assesses the total cost of an asset over its life cycle, including initial capital costs, maintenance costs, operating costs, and the asset’s residual value at the end of its life. Initial investment cost was calculated through P&ID preparation. Owing to the lack of commercialized plant studies, the cost estimations of accelerated carbonation were based on pilot-scale operations. The simulated MC processes are shown in Figure 1.
This was calculated based on the process of removing CO2 by inputting 300,000 tons of CaSO4 per year. The annual cost was evaluated by setting the lifetime of the initial investment facility to 10–25 years and the real discount rate to 3.2% (Supplementary Information). The results of the calculations are presented in Table 3. Details of the investment cost, operating cost, and operating income can be found in the Supplementary Information.
Operating costs accounted for most of the cost, and NH3 gas, an input raw material, accounted for 58.0% of the cost. The economic feasibility depends on the raw material required for the MC process; therefore, it must be re-evaluated according to the raw material price. (NH4)2SO4, a by-product, may also have different selling prices, which can improve economic feasibility, and should also reflect the sale of carbon credits.
The energy to be used for raw material crushing and the CO2 capture process can be saved, as this technology directly reacts with raw materials without pretreatment with flue gas. This is promising because it is carried out by a single process in an aqueous solution [76,77]. The facility is not structurally complicated; therefore, it is advantageous for scaling up. Depending on the connection with the target plant to be applied, there is the possibility of reducing the steam cost with the operating costs. After the carbonation reaction, a useful material is produced through the crystallization of (NH4)2SO4, thereby improving the economic feasibility of MC technology. Although the feasibility study was based on FGD gypsum, it is possible to estimate the carbonation cost for another waste gypsum with gypsum-specific cost adjustments.

6. Discussion

FGD gypsum and phosphogypsum were discussed to be utilized for MC. These two materials contain 53.24–95.05 wt% and 52.63–96.79 wt% of CaSO4, respectively. The amount of carbonation varies depending on the CaSO4 content. Temperature, CO2 partial pressure, CO2 flow rate, and NH3 concentration have influenced the kinetics and preparation of CaCO3. The kinetics become faster with elevated temperatures. The reaction rate is twice as fast at 40 °C than at room temperature. However, a moderate temperature is recommended because a high temperature accelerates the kinetic while decreasing the amount of CO2 that can be fixed. This reduced efficiency can be compensated for by increasing the CO2 partial pressure. Under high CO2 partial pressure, more CO32− is generated, which not only promotes carbonation, but also increases the effect of temperature. It is appropriate to increase the pressure with temperature for an efficient process. CO2 flow rate and NH3 concentration can act as factors that increase MC efficiency. Polymorphs of CaCO3 depend on the pH, impurities, and Ca2+/CO32− ratio along with the above factors, so it is necessary to create appropriate conditions according to the utilization plan of the prepared CaCO3.
Bench scale and pilot scale studies were also conducted using conditions derived from laboratory-scale batch studies. The applicability of the MC technology was improved through the research conducted to directly utilize the flue gas without separating/recovering CO2. When applied to CO2 generating facilities, there is no need for a recovery/separation device because flue gas is directly used. Research conducted as a continuous process can act as a bridgehead for the MC technology to be put to practical use. Moreover, it was shown that direct aqueous MC of waste gypsum using NH3 can also overcome techno-economic hassles. Although the input of NH3 accounts for a significant portion of the operating cost, the sale of ammonium sulfate as a by-product can improve economics.

7. Conclusions

Direct aqueous mineral carbonation (MC) of waste gypsum using NH3 is a technology that can help mitigate the global anthropogenic CO2 emissions problem. Recent advances of the technology by many researchers have shown a great potential for CO2 sequestration. The optimal conditions for CO2 sequestration were derived by analyzing the factors affecting the kinetics and preparation of CaCO3: temperature, CO2 partial pressure, CO2 flow rate, and NH3 concentration.
The recently conducted bench scale plant study also proved the field applicability of this technology. Moreover, the cost of sequestering 1 ton of CO2 based on a process that treats 300,000 tons of CO2 is USD 62.5, which is economically analyzed. The economic feasibility of applying this technology to the flue gas generation site has been established. However, more verification through various conditions and process design is required. There is a possibility that the economic efficiency will be further improved according to the CO2 reduction support policy by country and industry.
Before other large-scale CO2 sequestration technologies are put to practical use, it is an important technology that can serve as a bridgehead by utilizing these techno-economic advantages. To this end, a larger-scale empirical study is needed in the future.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/su14084436/s1.

Author Contributions

Conceptualization, S.-W.J. and H.J.; investigation, C.-U.K.; data curation, C.-U.K.; writing—original draft preparation, C.-U.K.; writing—review and editing, S.-W.J. and H.J.; supervision, H.J.; funding acquisition, H.J. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government (MOTIE) (20214710100030, Demonstration of mineral carbonation using FGD gypsum and development of CDM methodology).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Seifritz, W. CO2 disposal by means of silicates. Nature 1990, 345, 486. [Google Scholar] [CrossRef]
  2. Sanna, A.; Uibu, M.; Caramanna, G.; Kuusik, R.; Maroto-Valer, M. A review of mineral carbonation technologies to sequester CO2. Chem. Soc. Rev. 2014, 43, 8049–8080. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  3. Doucet, F. Scoping Study on CO2 Mineralization Technologies; Report No CGS-2011-007; Council for Geoscience: Pretoria, South Africa, 2011; p. 88. [Google Scholar]
  4. Wang, F.; Dreisinger, D.B.; Jarvis, M.; Hitchins, T. The technology of CO2 sequestration by mineral carbonation: Current status and future prospects. Can. Metall. Q. 2017, 57, 46–58. [Google Scholar] [CrossRef] [Green Version]
  5. Kunzler, C.; Alves, N.; Pereira, E.; Nienczewski, J.; Ligabue, R.; Einloft, S.; Dullius, J. CO2 storage with indirect carbonation using industrial waste. Energy Procedia 2011, 4, 1010–1017. [Google Scholar] [CrossRef] [Green Version]
  6. Senadeera, K.R.; Jayasinghe, T.K.; Jayasundara, P.M.; Nanayakkara, G.; Rathnayake, M. Investigation of CO2 Sequestration Possibility via Indirect Mineral Carbonation using Waste Coal Fly Ash. In Proceedings of the 2020 Moratuwa Engineering Research Conference (MERCon), Moratuwa, Sri Lanka, 28–30 July 2020; pp. 119–123. [Google Scholar]
  7. Ćwik, A.; Casanova, I.; Rausis, K.; Zarębska, K. Utilization of high-calcium fly ashes through mineral carbonation: The cases for Greece, Poland and Spain. J. CO2 Util. 2019, 32, 155–162. [Google Scholar] [CrossRef]
  8. Revathy, T.D.R.; Ramachandran, A.; Palanivelu, K. Carbon capture and storage using coal fly ash with flue gas. Clean Technol. Environ. Policy 2021, 1–19. [Google Scholar] [CrossRef]
  9. Luo, Y.; He, D. Research status and future challenge for CO2 sequestration by mineral carbonation strategy using iron and steel slag. Environ. Sci. Pollut. Res. 2021, 28, 49383–49409. [Google Scholar] [CrossRef]
  10. Liu, Q.; Liu, W.; Hu, J.; Wang, L.; Gao, J.; Liang, B.; Yue, H.; Zhang, G.; Luo, D.; Li, C. Energy-efficient mineral carbonation of blast furnace slag with high value-added products. J. Clean. Prod. 2018, 197, 242–252. [Google Scholar] [CrossRef]
  11. Aparicio, P.; Martín, D.; Baya-Arenas, R.; Flores-Alés, V. Behaviour of concrete and cement in carbon dioxide sequestration by mineral carbonation processes. Boletín Soc. Española Cerámica Vidr. 2020. [Google Scholar] [CrossRef]
  12. Abe, M.; Tanaka, S.; Noguchi, M.; Yamasaki, A. Investigation of Mineral Carbonation with Direct Bubbling into Concrete Sludge. ACS Omega 2021, 6, 15564–15571. [Google Scholar] [CrossRef]
  13. Kusin, F.M.; Hasan, S.N.M.S.; Hassim, M.A.; Molahid, V.L.M. Mineral carbonation of sedimentary mine waste for carbon sequestration and potential reutilization as cementitious material. Environ. Sci. Pollut. Res. 2020, 27, 12767–12780. [Google Scholar] [CrossRef] [PubMed]
  14. Molahid, V.L.M.; Kusin, F.M.; Hasan, S.N.M.S.; Ramli, N.A.A.; Abdullah, A.M. CO2 Sequestration through Mineral Carbonation: Effect of Different Parameters on Carbonation of Fe-Rich Mine Waste Materials. Processes 2022, 10, 432. [Google Scholar] [CrossRef]
  15. Ding, W.; Chen, Q.; Sun, H.; Peng, T. Modified mineral carbonation of phosphogypsum for CO2 sequestration. J. CO2 Util. 2019, 34, 507–515. [Google Scholar] [CrossRef]
  16. Wang, B.; Pan, Z.; Cheng, H.; Guan, Y.; Zhang, Z.; Cheng, F. CO2 sequestration: High conversion of gypsum into CaCO3 by ultrasonic carbonation. Environ. Chem. Lett. 2020, 18, 1369–1377. [Google Scholar] [CrossRef]
  17. Wang, B.; Yang, L.; Luo, T.; Cao, J. Study on the Kinetics of Hydration Transformation from Hemihydrate Phosphogypsum to Dihydrate Phosphogypsum in Simulated Wet Process Phosphoric Acid. ACS Omega 2021, 6, 7342–7350. [Google Scholar] [CrossRef]
  18. Koralegedara, N.H.; Pinto, P.X.; Dionysiou, D.D.; Al-Abed, S.R. Recent advances in flue gas desulfurization gypsum processes and applications–A review. J. Environ. Manag. 2019, 251, 109572. [Google Scholar] [CrossRef]
  19. Wenyi, T.; Suping, G.; Wei, X.; Youxu, L.; Zixin, Z. Feature changes of mercury during the carbonation of FGD gypsum from different sources. Fuel 2018, 212, 19–26. [Google Scholar] [CrossRef]
  20. Zhou, J.; Sheng, Z.; Li, T.; Shu, Z.; Chen, Y.; Wang, Y. Preparation of hardened tiles from waste phosphogypsum by a new intermittent pressing hydration. Ceram. Int. 2016, 42, 7237–7245. [Google Scholar] [CrossRef]
  21. Lee, M.G.; Jang, Y.N.; Ryu, K.W.; Kim, W.; Bang, J.-H. Mineral carbonation of flue gas desulfurization gypsum for CO2 sequestration. Energy 2012, 47, 370–377. [Google Scholar] [CrossRef]
  22. KIGAM. Utilization and Sequestration of CO2 Using Industrial Minerals; Korea Institute of Geoscience and Mineral Resources: Daejeon, Korea, 2015; pp. 1–596. [Google Scholar]
  23. Idboufrade, A.; Bouargane, B.; Ennasraoui, B.; Biyoune, M.G.; Bachar, A.; Bakiz, B.; Atbir, A.; Mançour-Billah, S. Phosphogypsum Two-Step Ammonia-Carbonation Resulting in Ammonium Sulfate and Calcium Carbonate Synthesis: Effect of the Molar Ratio OH−/Ca2+ on the Conversion Process. Waste Biomass Valorization 2022, 13, 1795–1806. [Google Scholar] [CrossRef]
  24. Jeon, C.W.; Park, S.; Bang, J.-H.; Chae, S.; Song, K.; Lee, S.-W. Nonpolar Surface Modification Using Fatty Acids and Its Effect on Calcite from Mineral Carbonation of Desulfurized Gypsum. Coatings 2018, 8, 43. [Google Scholar] [CrossRef] [Green Version]
  25. Wang, B.; Pan, Z.; Cheng, H.; Zhang, Z.; Cheng, F. A review of carbon dioxide sequestration by mineral carbonation of industrial byproduct gypsum. J. Clean. Prod. 2021, 302, 126930. [Google Scholar] [CrossRef]
  26. Altiner, M. Effect of Alkaline Types on the Production of Calcium Carbonate Particles from Gypsum Waste for Fixation of CO2 by Mineral Carbonation. Int. J. Coal Prep. Util. 2019, 39, 113–131. [Google Scholar] [CrossRef]
  27. Song, K.; Jang, Y.-N.; Kim, W.; Lee, M.G.; Shin, D.; Bang, J.-H.; Jeon, C.W.; Chae, S.C. Precipitation of calcium carbonate during direct aqueous carbonation of flue gas desulfurization gypsum. Chem. Eng. J. 2012, 213, 251–258. [Google Scholar] [CrossRef]
  28. Liu, W.; Teng, L.; Rohani, S.; Qin, Z.; Zhao, B.; Xu, C.C.; Ren, S.; Liu, Q.; Liang, B. CO2 mineral carbonation using industrial solid wastes: A review of recent developments. Chem. Eng. J. 2021, 416, 129093. [Google Scholar] [CrossRef]
  29. Bhawan, P.; Nagar, E.A. Guidelines for Management, Handling, Utilisation and Disposal of Phosphogypsum Generated from Phosphoric Acid Plants; Central Pollution Control Board: New Delhi, India, 2014. [Google Scholar]
  30. El Issiouy, S.; Atbir, A.; Mançour-Billah, S.; Bellajrou, R.; Boukbir, L.; El Hadek, M. Thermal treatment of moroccan phosphogypsum. In Proceedings of the MATEC Web of Conferences, online, 1 July 2013; p. 01030. [Google Scholar] [CrossRef] [Green Version]
  31. Agency, I.A.E. Radiation Protection and Management of NORM Residues in the Phosphate Industry; 9201358105; International Atomic Energy Agency: Vienna, Austria, 2013. [Google Scholar]
  32. Ma, Y.; Nie, Q.; Xiao, R.; Hu, W.; Han, B.; Polaczyk, P.A.; Huang, B. Experimental investigation of utilizing waste flue gas desulfurized gypsum as backfill materials. Constr. Build. Mater. 2020, 245, 118393. [Google Scholar] [CrossRef]
  33. Wang, X.; Ni, W.; Li, J.; Zhang, S.; Hitch, M.; Pascual, R. Carbonation of steel slag and gypsum for building materials and associated reaction mechanisms. Cem. Concr. Res. 2019, 125, 105893. [Google Scholar] [CrossRef]
  34. Wang, B.; Pan, Z.; Du, Z.; Cheng, H.; Cheng, F. Effect of impure components in flue gas desulfurization (FGD) gypsum on the generation of polymorph CaCO3 during carbonation reaction. J. Hazard. Mater. 2019, 369, 236–243. [Google Scholar] [CrossRef]
  35. Telesca, A.; Marroccoli, M.; Calabrese, D.; Valenti, G.L.; Montagnaro, F. Flue gas desulfurization gypsum and coal fly ash as basic components of prefabricated building materials. Waste Manag. 2013, 33, 628–633. [Google Scholar] [CrossRef]
  36. Seo, S.K.; Kim, Y.; Chu, Y.S.; Cho, H.K. Experimental Study on the Carbonation Properties of Dry Desulfurized Gypsum. J. Korean Ceram. Soc. 2018, 55, 44–49. [Google Scholar] [CrossRef] [Green Version]
  37. Jiang, L.; Li, C.; Wang, C.; Xu, N.; Chu, H. Utilization of flue gas desulfurization gypsum as an activation agent for high-volume slag concrete. J. Clean. Prod. 2018, 205, 589–598. [Google Scholar] [CrossRef]
  38. Yan, Y.; Li, Q.; Sun, X.; Ren, Z.; He, F.; Wang, Y.; Wang, L. Recycling flue gas desulphurization (FGD) gypsum for removal of Pb(II) and Cd(II) from wastewater. J. Colloid Interface Sci. 2015, 457, 86–95. [Google Scholar] [CrossRef] [PubMed]
  39. Miao, M.; Feng, X.; Wang, G.; Cao, S.; Shi, W.; Shi, L. Direct transformation of FGD gypsum to calcium sulfate hemihydrate whiskers: Preparation, simulations, and process analysis. Particuology 2015, 19, 53–59. [Google Scholar] [CrossRef]
  40. Li, J.; Zhuang, X.; Leiva, C.; Cornejo, A.; Font, O.; Querol, X.; Moeno, N.; Arenas, C.; Fernández-Pereira, C. Potential utilization of FGD gypsum and fly ash from a Chinese power plant for manufacturing fire-resistant panels. Constr. Build. Mater. 2015, 95, 910–921. [Google Scholar] [CrossRef]
  41. Lee, M.G.; Ryu, K.W.; Chae, S.C.; Jang, Y.N. Effects of temperature on the carbonation of flue gas desulphurization gypsum using a CO2/N2 gas mixture. Environ. Technol. 2015, 36, 106–114. [Google Scholar] [CrossRef] [PubMed]
  42. Li, X.; Du, J.; Gao, L.; He, S.; Gan, L.; Sun, C.; Shi, Y. Immobilization of phosphogypsum for cemented paste backfill and its environmental effect. J. Clean. Prod. 2017, 156, 137–146. [Google Scholar] [CrossRef]
  43. Vaičiukynienė, D.; Nizevičienė, D.; Kielė, A.; Janavičius, E.; Pupeikis, D. Effect of phosphogypsum on the stability upon firing treatment of alkali-activated slag. Constr. Build. Mater. 2018, 184, 485–491. [Google Scholar] [CrossRef]
  44. Nizevičienė, D.; Vaičiukynienė, D.; Michalik, B.; Bonczyk, M.; Vaitkevičius, V.; Jusas, V. The treatment of phosphogypsum with zeolite to use it in binding material. Constr. Build. Mater. 2018, 180, 134–142. [Google Scholar] [CrossRef]
  45. Tian, T.; Yan, Y.; Hu, Z.; Xu, Y.; Chen, Y.; Shi, J. Utilization of original phosphogypsum for the preparation of foam concrete. Constr. Build. Mater. 2016, 115, 143–152. [Google Scholar] [CrossRef]
  46. Hua, S.; Wang, K.; Yao, X.; Xu, W.; He, Y. Effects of fibers on mechanical properties and freeze-thaw resistance of phosphogypsum-slag based cementitious materials. Constr. Build. Mater. 2016, 121, 290–299. [Google Scholar] [CrossRef]
  47. Zieliński, M. Influence of constant magnetic field on the properties of waste phosphogypsum and fly ash composites. Constr. Build. Mater. 2015, 89, 13–24. [Google Scholar] [CrossRef]
  48. Rashad, A.M. Potential use of phosphogypsum in alkali-activated fly ash under the effects of elevated temperatures and thermal shock cycles. J. Clean. Prod. 2015, 87, 717–725. [Google Scholar] [CrossRef]
  49. Hentati, O.; Abrantes, N.; Caetano, A.L.; Bouguerra, S.; Gonçalves, F.; Römbke, J.; Pereira, R. Phosphogypsum as a soil fertilizer: Ecotoxicity of amended soil and elutriates to bacteria, invertebrates, algae and plants. J. Hazard. Mater. 2015, 294, 80–89. [Google Scholar] [CrossRef] [PubMed]
  50. Contreras, M.; Pérez-López, R.; Gázquez, M.J.; Morales-Flórez, V.; Santos, A.; Esquivias, L.; Bolívar, J.P. Fractionation and fluxes of metals and radionuclides during the recycling process of phosphogypsum wastes applied to mineral CO2 sequestration. Waste Manag. 2015, 45, 412–419. [Google Scholar] [CrossRef] [Green Version]
  51. Shen, Y.; Qian, J.; Chai, J.; Fan, Y. Calcium sulphoaluminate cements made with phosphogypsum: Production issues and material properties. Cem. Concr. Compos. 2014, 48, 67–74. [Google Scholar] [CrossRef]
  52. Huang, Y.; Lu, J.; Chen, F.; Shui, Z. The chloride permeability of persulphated phosphogypsum-slag cement concrete. J. Wuhan Univ. Technol. Mater. Sci. Ed. 2016, 31, 1031–1037. [Google Scholar] [CrossRef]
  53. Zhao, L.; Wan, T.; Yang, X.; Yang, L.; Kong, X.; Zhang, Z.; Wang, X. Effects of kaolinite addition on the melting characteristics of the reaction between phosphogypsum and CaS. J. Therm. Anal. Calorim. 2015, 119, 2119–2126. [Google Scholar] [CrossRef]
  54. Zhao, H.; Li, H.; Bao, W.; Wang, C.; Li, S.; Lin, W. Experimental study of enhanced phosphogypsum carbonation with ammonia under increased CO2 pressure. J. CO2 Util. 2015, 11, 10–19. [Google Scholar] [CrossRef]
  55. Kadirova, Z.C.; Hojamberdiev, M.; Bo, L.; Hojiyev, R.; Okada, K. Ion uptake properties of low-cost inorganic sorption materials in the CaO–Al2O3–SiO2 system prepared from phosphogypsum and kaolin. J. Clean. Prod. 2014, 83, 483–490. [Google Scholar] [CrossRef]
  56. Bodénan, F.; Bourgeois, F.; Petiot, C.; Augé, T.; Bonfils, B.; Julcour-Lebigue, C.; Guyot, F.; Boukary, A.; Tremosa, J.; Lassin, A.; et al. Ex-situ mineral carbonation: Resources, process and environmental assessment (Carmex project). In Proceedings of the 4th International Conference on Accelerated Carbonation for Environmental and Materials Engineering, Leuven, Belgium, 10–12 April 2013. [Google Scholar]
  57. Tan, W.; Zhang, Z.; Li, H.; Li, Y.; Shen, Z. Carbonation of gypsum from wet flue gas desulfurization process: Experiments and modeling. Environ. Sci. Pollut. Res. 2017, 24, 8602–8608. [Google Scholar] [CrossRef]
  58. Tan, W.; Fan, W.; Li, H.; Zhang, Z.; Zhu, Y. Removal of Hg, As in FGD gypsum by different aqueous ammonia (amines) during CO2 sequestration. Waste Manag. Res. 2017, 35, 1296–1301. [Google Scholar] [CrossRef]
  59. Azdarpour, A.; Asadullah, M.; Junin, R.; Mohammadian, E.; Hamidi, H.; Daud, A.R.M.; Manan, M. Extraction of calcium from red gypsum for calcium carbonate production. Fuel Process. Technol. 2015, 130, 12–19. [Google Scholar] [CrossRef]
  60. Park, A.H.A.; Jadhav, R.; Fan, L.S. CO2 mineral sequestration: Chemically enhanced aqueous carbonation of serpentine. Can. J. Chem. Eng. 2003, 81, 885–890. [Google Scholar] [CrossRef]
  61. Sun, J.; Liu, W.; Wang, W.; Hu, Y.; Yang, X.; Chen, H.; Zhang, Y.; Li, X.; Xu, M. Optimizing synergy between phosphogypsum disposal and cement plant CO2 capture by the calcium looping process. Energy Fuels 2016, 30, 1256–1265. [Google Scholar] [CrossRef]
  62. Song, K.; Jang, Y.-N.; Kim, W.; Lee, M.G.; Shin, D.; Bang, J.-H.; Jeon, C.W.; Chae, S.C. Factors affecting the precipitation of pure calcium carbonate during the direct aqueous carbonation of flue gas desulfurization gypsum. Energy 2014, 65, 527–532. [Google Scholar] [CrossRef]
  63. Zhao, J.; Song, X.; Sun, Z.; Sun, S.; Yu, J. Simulation and control on ammonia carbonation under low temperature and pressure. CIESC J. 2013, 64, 3626–3632. [Google Scholar] [CrossRef]
  64. Choi, K.-M.; Kuroda, K. Polymorph control of calcium carbonate on the surface of mesoporous silica. Cryst. Growth Des. 2012, 12, 887–893. [Google Scholar] [CrossRef]
  65. Kitamura, M. Strategy for control of crystallization of polymorphs. CrystEngComm 2009, 11, 949–964. [Google Scholar] [CrossRef]
  66. Chang, R.; Choi, D.; Kim, M.H.; Park, Y. Tuning crystal polymorphisms and structural investigation of precipitated calcium carbonates for CO2 mineralization. ACS Sustain. Chem. Eng. 2017, 5, 1659–1667. [Google Scholar] [CrossRef]
  67. Svenskaya, Y.I.; Fattah, H.; Inozemtseva, O.A.; Ivanova, A.G.; Shtykov, S.N.; Gorin, D.A.; Parakhonskiy, B.V. Key parameters for size-and shape-controlled synthesis of vaterite particles. Cryst. Growth Des. 2018, 18, 331–337. [Google Scholar] [CrossRef]
  68. Song, K.; Kim, W.; Bang, J.-H.; Park, S.; Jeon, C.W. Polymorphs of pure calcium carbonate prepared by the mineral carbonation of flue gas desulfurization gypsum. Mater. Des. 2015, 83, 308–313. [Google Scholar] [CrossRef]
  69. Mattila, H.-P.; Zevenhoven, R. Mineral carbonation of phosphogypsum waste for production of useful carbonate and sulfate salts. Front. Energy Res. 2015, 3, 48. [Google Scholar] [CrossRef] [Green Version]
  70. Lu, S.Q.; Lan, P.Q.; Wu, S.F. Preparation of nano-CaCO3 from phosphogypsum by gas–liquid–solid reaction for CO2 sorption. Ind. Eng. Chem. Res. 2016, 55, 10172–10177. [Google Scholar] [CrossRef]
  71. Zhou, G.-T.; Yao, Q.-Z.; Fu, S.-Q.; Guan, Y.-B. Controlled crystallization of unstable vaterite with distinct morphologies and their polymorphic transition to stable calcite. Eur. J. Mineral. 2010, 22, 259–269. [Google Scholar] [CrossRef] [Green Version]
  72. Pan, S.-Y.; Chang, E.; Chiang, P.-C. CO2 capture by accelerated carbonation of alkaline wastes: A review on its principles and applications. Aerosol Air Qual. Res. 2012, 12, 770–791. [Google Scholar] [CrossRef]
  73. Sanna, A.; Dri, M.; Hall, M.R.; Maroto-Valer, M. Waste materials for carbon capture and storage by mineralisation (CCSM)—A UK perspective. Appl. Energy 2012, 99, 545–554. [Google Scholar] [CrossRef]
  74. Gerdemann, S.J.; O’Connor, W.K.; Dahlin, D.C.; Penner, L.R.; Rush, H. Ex situ aqueous mineral carbonation. Environ. Sci. Technol. 2007, 41, 2587–2593. [Google Scholar] [CrossRef]
  75. Pan, S.-Y.; Chiang, P.-C.; Chen, Y.-H.; Chen, C.-D.; Lin, H.-Y.; Chang, E.-E. Systematic approach to determination of maximum achievable capture capacity via leaching and carbonation processes for alkaline steelmaking wastes in a rotating packed bed. Environ. Sci. Technol. 2013, 47, 13677–13685. [Google Scholar] [CrossRef]
  76. Huijgen, W.J.J.; Comans, R.N.J.; Witkamp, G.-J. Cost evaluation of CO2 sequestration by aqueous mineral carbonation. Energy Convers. Manag. 2007, 48, 1923–1935. [Google Scholar] [CrossRef] [Green Version]
  77. Lackner, K.S. A guide to CO2 sequestration. Science 2003, 300, 1677–1678. [Google Scholar] [CrossRef]
Sustainability 14 04436 g001 550
Figure 1. Circulation of desulfurized gypsum in coal-fired power plants through application of mineral carbonation (MC) technology (Gas composition was referenced in Lee et al. [21], KIGAM [22]).
Figure 1. Circulation of desulfurized gypsum in coal-fired power plants through application of mineral carbonation (MC) technology (Gas composition was referenced in Lee et al. [21], KIGAM [22]).
Sustainability 14 04436 g001
Sustainability 14 04436 g002 550
Figure 2. Conversion rate as a function of initial temperature (Reprinted/adapted with permission from [54]. 2015, Elsevier).
Figure 2. Conversion rate as a function of initial temperature (Reprinted/adapted with permission from [54]. 2015, Elsevier).
Sustainability 14 04436 g002
Sustainability 14 04436 g003 550
Figure 3. Conversion rate as a function of CO2 flow rate (Reprinted/adapted with permission from [21]. 2012, Elsevier).
Figure 3. Conversion rate as a function of CO2 flow rate (Reprinted/adapted with permission from [21]. 2012, Elsevier).
Sustainability 14 04436 g003
Sustainability 14 04436 g004 550
Figure 4. Conversion rate as a function of ammonia-to-gypsum ratio (Reprinted/adapted with permission from [54]. 2015, Elsevier).
Figure 4. Conversion rate as a function of ammonia-to-gypsum ratio (Reprinted/adapted with permission from [54]. 2015, Elsevier).
Sustainability 14 04436 g004
Sustainability 14 04436 g005 550
Figure 5. Bench-scale continuous gypsum carbonation facility manufactured by KIGAM (left—bubble column reactor; right—CO2 and nitrogen (N2) injection facilities) [22].
Figure 5. Bench-scale continuous gypsum carbonation facility manufactured by KIGAM (left—bubble column reactor; right—CO2 and nitrogen (N2) injection facilities) [22].
Sustainability 14 04436 g005
Table
Table 1. Oxide composition of flue gas desulfurization (FGD) gypsum for different studies.
Table 1. Oxide composition of flue gas desulfurization (FGD) gypsum for different studies.
Reference[32][33][34][26][35][36][37][38][39][40][41]
SO342.5843.5747.8046.5136.9031.3149.7455.9040.3440.8044.84
CaO32.2548.0639.5032.5031.9053.4037.9540.1025.2728.1032.49
SiO20.782.951.05-3.302.952.392.121.692.000.70
MgO0.521.480.17-3.800.890.250.180.981.00-
Fe2O30.320.580.300.430.300.540.260.290.180.500.22
Al2O30.121.180.930.561.000.911.431.230.341.200.42
SrO---0.04-------
K2O--0.09-----0.030.100.10
Na2O-----0.59---0.300.13
TiO2-0.39-0.020.05---0.020.07-
CuO---0.02-------
MnO-1.18-0.03-----0.01-
P2O5-0.03--0.01-----0.08
Cl--0.077---0.26----
Other-0.58---------
LOI18.34-10.0819.7022.408.417.72---20.18
* CaSO472.4074.0981.2879.0962.7553.2484.5895.0568.5969.3876.25
** CaCO34.3331.3110.74-10.8156.175.551.69--1.93
* CaSO4 content is calculated assuming that all sulfur constitutes gypsum. ** CaCO3 content is calculated from the Ca content remaining after composing CaSO4.
Table
Table 2. Oxide composition of phosphogypsum for different studies.
Table 2. Oxide composition of phosphogypsum for different studies.
Reference[42][43][44][45][46][47][48][49][50][51][30][52][53][54][55][56]
Constituent (wt%)
SO356.6852.7153.4852.5630.9542.8334.5143.8051.5344.4742.9042.1046.0256.9249.8944.40
CaO38.3939.0638.6032.8331.0531.0032.1430.7036.6030.5230.5031.6432.1233.6436.4832.80
SiO21.370.340.3712.874.860.138.821.380.615.059.504.865.946.311.891.37
MgO0.120.210.040.080.26-0.090.01--0.300.290.30--0.01
Fe2O30.450.040.140.10-0.500.350.02-0.350.900.271.540.33-0.03
Al2O30.350.070.130.55-0.770.290.100.180.662.804.380.500.640.080.11
K2O0.12--0.160.41---0.020.14------
Na2O0.07--0.03---0.060.130.08-0.17----
TiO20.06--0.070.20----0.07------
P2O52.261.110.82-3.573.911.722.510.330.810.501.051.390.710.441.69
CO2----------4.50-----
F-0.060.14--0.260.801.93-0.260.150.12-0.91--
LOI-6.406.4011.2022.9120.0021.00--18.293.5021.19--11.2222.30
* CaSO496.3889.6390.9489.3752.6372.8358.6874.4887.6275.6272.9571.5978.2596.7984.8375.50
** Ca3(PO4)2-2.431.79-7.808.543.765.480.72-1.092.29--0.963.69
* CaSO4 content is calculated assuming that all sulfur constitutes gypsum. ** Ca3(PO4)2 content is calculated from the Ca content remaining after composing CaSO4.
Table
Table 3. Life cycle costing (LCC) for mineral carbonation (MC) by inputting 300,000 tons of CaSO4 with NH3.
Table 3. Life cycle costing (LCC) for mineral carbonation (MC) by inputting 300,000 tons of CaSO4 with NH3.
Initial Investment CostTotal
Converted to Annual Expenses
(3.2% of Real Discount Rate)		USD 33,672,343
USD 2,455,073/Year
EquipmentDevices, heat exchangers, and vesselsUSD 19,721,208
Pump and blowerUSD 2,401,836
InstrumentUSD 1,578,514
ConstructionControl automation construction,
Control panel and electrical construction		USD 861,436
Plumbing constructionUSD 4,090,150
Structure constructionUSD 1,577,629
Transport and installation workUSD 208,681
Thermal insulation constructionUSD 801,336
EngineeringUSD 2,431,553
Operating cost USD 58,703,171/year
MaterialAmmonia gas (NH3)USD 35,477,369/year
Flue gasUSD 0/year
WaterUSD 6193/year
UtilitySteamUSD 17,981,803/year
ElectricityUSD 4,496,312/year
Cooling waterUSD 434,798/year
Labor costs USD 306,696/year
Operating income USD 42,395,139/year
Ammonium sulfate ((NH4)2SO4)USD 42,395,139/year
Total USD 18,736,105/year
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Kang, C.-U.; Ji, S.-W.; Jo, H. Recycling of Industrial Waste Gypsum Using Mineral Carbonation. Sustainability 2022, 14, 4436. https://doi.org/10.3390/su14084436

AMA Style

Kang C-U, Ji S-W, Jo H. Recycling of Industrial Waste Gypsum Using Mineral Carbonation. Sustainability. 2022; 14(8):4436. https://doi.org/10.3390/su14084436

Chicago/Turabian Style

Kang, Chan-Ung, Sang-Woo Ji, and Hwanju Jo. 2022. "Recycling of Industrial Waste Gypsum Using Mineral Carbonation" Sustainability 14, no. 8: 4436. https://doi.org/10.3390/su14084436

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop