Sulfate Resistance Research Articles

Facile Synthesis of Cu-Exchanged Zeolite Catalysts with Only Cu2+-2Z Species: Enhancing Hydrothermal Stability and Sulfur Resistance for NH3-SCR.

For Cu-exchanged zeolite catalysts, Cu2+ ions existing as Cu2+-2Z and [Cu(OH)]+-Z (where Z represents a framework negative charge) are considered the active sites for the selective catalytic reduction of NOx with NH3 (NH3-SCR). Cu2+-2Z is more hydrothermally stable and sulfur poisoning-resistant than [Cu(OH)]+-Z. In this work, Cu-CHA and Cu-LTA catalysts containing only Cu2+-2Z species were successfully synthesized by a novel impregnation (NIM) method, exhibiting remarkably enhanced hydrothermal stability and sulfur resistance compared with any reported Cu-exchanged zeolite catalysts. It was also found that the [Cu(OH)]+-Z sites can convert to Cu2+-2Z by treating at high temperature (850 °C) due to the self-reduction of Cu2+ to highly mobile Cu+. The use of the NIM method not only significantly simplifies the preparation of the catalysts but also can precisely control the Cu loading, which is very important for the control of Cu species. Many other zeolite catalysts can be prepared by this method.

Evaluating the performance and environmental impact of low calcium fly ash-based geopolymer in comparison to OPC-based concrete.

The current paper explores the performance, microstructure and environmental consequences of low-calcium fly ash-based geopolymer concrete compared to OPC-based concrete. The performance of the concrete is assessed based on strength, permeability, sulfate resistance, and acid attack. Two geopolymer mixes were designed by adjusting the binder dosage. The geopolymer concrete mixes achieved 11-16% higher strength than OPC-based concrete. However, increasing the binder dosage from 30 to 40% led to 5% reduction in strength at later ages. Geopolymer concrete demonstrated superior resistance to sulfate and acid attacks, as well as lower penetration depth and permeability coefficient compared to OPC-based concrete. Microstructural analysis was conducted using XRD and SEM techniques, identifying sodium aluminosilicate gel as the product formed during the polymerization process. The environmental impact was evaluated through a life cycle assessment using a cradle-to-gate approach. Geopolymer concrete requires 25-33% less energy and emits 14-28% less kg-CO2 eq. than OPC-based concrete. The production of OPC-based concrete had the greatest negative environmental impact, except in the categories of metal depletion (MDP) and ionizing radiation (IRP_HE). In geopolymer concrete, the use of alkaline activators accounted for higher energy consumption and accounted for 73-75% kg-CO2 eq. emissions. Overall, fly ash-based geopolymer concrete showed higher strength and excellent resistance to acid and sulfate attacks, along with a lower carbon footprint and energy consumption.

Influence of Portland-limestone cement composition on sulfate attack performance

This research evaluates the sulfate attack performance of Portland-limestone cements (PLCs) with varying limestone compositions. Specimens prepared by replacing Type I/II and Type V cement with up to 20% limestone powders and fly ash are examined for their sulfate resistance in sodium and magnesium sulfate solutions at 5 °C and 23 °C by expansion measurements, an accelerated strength test, visual observations, and X-ray diffraction. For the materials tested, higher calcitic limestone contents increased expansion up to 290% with 20% limestone when added to Type I/II cement but decreased expansion up to 48% with 14.6% limestone (calcitic + dolomitic) when added to Type V cement. Strength loss was not proportional to the percentage of limestone added to the cements. Dolomitic limestone improved sulfate resistance as indicated by increased strength development in magnesium sulfate and reduced expansion in both solutions. Ettringite, thaumasite, gypsum, and brucite were the main sulfate attack phases detected at 5 °C.

Microstructures of Directionally Solidified Nb15Ti55Fe30 Alloy and Its Hydrogen Permeation Properties in the Presence of H2S

Currently, the main limitations of Pd-coated Nb-TiFe dual-phase alloys include insufficient hydrogen permeability, susceptibility to hydrogen embrittlement (HE), and poor tolerance of H2S poisoning. To address these issues, this study proposes a series of improvements. First, a novel Nb15Ti55Fe30 alloy composed of a well-aligned Nb-TiFe eutectic was successfully prepared using directional solidification (DS) technology. After deposition with a Pd catalytic layer, this alloy exhibits high hydrogen permeability of 3.71 × 10−8 mol H2 m−1 s−1 Pa−1/2 at 673 K, which is 1.4 times greater than that of the as-cast counterpart. Second, to improve the H2S corrosion resistance, a new Pd88Au12 catalytic layer was deposited on the surface using a multi-target magnetic control sputtering system. Upon testing in a 100 ppm H2/H2S mixture, this membrane exhibited better resistance to bulk sulfidation and a higher permeance recovery (ca. 58%) compared to pure Pd-coated membrane. This improvement is primarily due to the lower adsorption energies of the former with H2S, which hinders the formation of bulk Pd4S. Finally, the composition region of the Pd-Au catalytic membrane with high comprehensive performance was determined for the first time, revealing that optimal performance occurs at around 12–18 at.% Au. This finding explains how this composition maintains a balance between high H2 permeability and excellent sulfur resistance. The significance of this study lies in its practical solutions for simultaneously improving hydrogen permeability and resistance to H2S poisoning in Nb-based composite membranes.

Enhancing NH3-SCR denitrification performance through synergistic A- and B-site effects via CeFe modification of LaMnO3

ABO3 type perovskite catalysts are widely used in NH3-SCR to remove NOx due to excellent low-temperature reduction performance. To study the synergistic effect of A and B sites on the structure, morphology and redox performance of modified perovskite catalysts (La1-xCexMn1-yFeyO3), LaMnO3 perovskite catalysts were co-doped with CeFe by sol-gel method, and the crystal structure, surface chemical environment, optimal metal co-doping ratio and surface adsorption of the modified perovskite catalysts were clarified through various characterizations. In addition, through first-principles calculations, the differential charge density and binding energy of each doping system were analyzed, the relationship between the difficulty of Ce doping and the electronic population of Mn atoms and the redox ability of the catalyst was discussed, and the key bond types and their changing rules in perovskite catalytic reduction were clarified. The results showed that co-doping Ce and Fe could improve the denitrification efficiency and sulfur resistance of the catalyst. When the Fe doping ratio is 0.1, the denitrification activity is the highest. Among them, the La0.9Ce0.1Mn0.9Fe0.1O3 catalyst showed the most favorable active acid site distribution and the best reduction performance, which was conducive to the adsorption and redox of gas molecules on the catalyst surface. At the same time, when the A and B sites were co-doped, the electron transferred mainly occurs between Ce ions and Fe ions, forming a synergistic effect and changing the covalent components between Mn-O and Fe-O bonds. This made the valence states of Mn and Fe ions more, enhanced the catalytic activity of perovskite, and promoted the redox of NO on the catalyst surface, thus providing a new idea for the redox reaction pathway of modified perovskite catalysts.

Experimental analysis on Self Compacting Concrete by using Nano - Silica Gel

Abstract: Self-Compacting Concrete (SCC) has gained widespread recognition in modern construction due to its ability to flow under its weight, eliminating the need for mechanical vibration. Despite its numerous advantages, challenges such as maintaining stability, durability, and achieving optimal mechanical performance persist. Incorporating nano-silica gel, a material known for its high pozzolanic activity and micro-filling capability, offers a promising solution to address these challenges. This experimental study evaluates the impact of nano-silica gel on the fresh, mechanical, and durability properties of SCC. The research involves preparing SCC mixes with varying nano-silica gel dosages (0.5%, 1%, 1.5%, and 2% by weight of cement) and analyzing their performance through a series of standardized tests. Fresh properties such as slump flow, T500 flow time, and V-funnel tests are used to assess workability and flow characteristics. Hardened properties, including compressive strength, split tensile strength, and flexural strength, are evaluated at different curing ages. Durability is analyzed through Rapid Chloride Penetration and Sulfate Resistance tests to assess the resistance to chemical attacks. Results indicate that the inclusion of nano-silica gel significantly enhances the flowability, compressive strength, and durability of SCC. The optimal performance is observed at 1% nano-silica gel dosage, beyond which a reduction in workability and strength occurs due to increased particle agglomeration. This study demonstrates that nano-silica gel can substantially improve SCC properties, making it a viable material for high-performance and sustainable construction practices. These findings contribute to the ongoing development of advanced concrete technologies, paving the way for future research in optimizing SCC mixes with nano-materials.

Insights into P-doping effect of the activity and anti-SO2/H2O poisoning of V2O5-MoO3/TiO2 catalysts for NH3-SCR

With the increasingly stringent flue gas emission standards, water-sulfur poisoning has become one of the most pressing problems in the SCR process of coal-fired power plants.SO2 not only deactivates the catalyst, but also reacts with water and NH3 to form NH4HSO4, which then corrodes the equipment. Catalysts with water-sulfur tolerance urgently need to be developed. NH4H2PO4-modified V2O5-MoO3/TiO2 SCR catalysts is prepared by an improved wet impregnation method. The effect of P element modification on the denitration performance of the V2O5-MoO3/TiO2 SCR catalyst was studied, and the catalyst was characterized by XRD, BET, SEM, TEM, XPS, TPR, TPD and Raman. When the phosphorus doping amount was 0.6 % (wt%), the P0.6-SCR catalyst could achieve a NOx conversion rate of 95 %, and its optimal reaction temperature was 350 ℃. The characterization results show that the P element made the active components on the catalyst surface further dispersed, delayed the sintering of the catalyst at the calcination stage, and promoted the generation of B-acidic sites, enhances the surface acidity of the catalyst, and promotes the transition of VOx from a monomer state to a polymer state. Meanwhile, the P0.6-SCR catalyst exhibits outstanding sulfur resistance while ensuring high denitration efficiency.

Rheological, mechanical and durability properties of mortar containing brick waste as a partial replacement of sand

The investigation presented in this paper focuses on the feasibility of employing brick waste (BW), a byproduct of limestone, to make self-compacting mortar (SCM). The principle goal of this study contributes in increasing economic and environmental value by replacing sand with co-products and optimizing their handling and management. Six alternative mortar mix proportions, including BW at rates of 0 %, 5 %, 10 %, 15 %, 20 %, and 25 %, are tested for rheological properties (flow time, yield stress and viscosity), the mechanical (compressive strength and flexural strength), durability (water absorption/porosity, chloride penetration, sulfate resistance and SEM analysis). The deep in visitation showed that a SCM with a yield stress of 13.8 Pa, a 25 % BW replacement rate, and a viscosity of 11.7 Pa.S may reach a flow time of 74.2–64.1 S. In addition, mortars containing 25 % BW had a maximum compressive strength and flexural strength of 36.9 MPa and 4.03 MPa at 28 days, representing an 11.3 % and 39.2, respectively drop over the reference mortar BW0 %. The results showed the water absorption and the depth of chloride penetration increased by 86.2 % and 36 %, respectively. The sulfate resistance was decreased by 39 % as compared to those of the reference mortar (BW0 %). Scanning Electron Microscopy (SEM) observations showed that the BW25 % mortar contains several pores compared to those of BW10 % and BW0 %.

Construction dual active sites on confined ordered mesoporous CeWTi catalyst by CuSO4 modification for enhancing SO2 tolerance during low temperature NH3-SCR process

The full exposure of the active center is an important reason for the superior performance, and the excellent anti-SO2 poisoning ability is a key factor to ensure the service life for the low temperature NH3-SCR catalyst. In this study, the strategy of evaporation-induced self-assembly (EISA) was chosen to directly confined CuSO4 to the framework structure of ordered mesoporous CeWTiOx (CWT-OM) catalyst. Metal sulfate plays a dual role in low temperature activity and sulfur resistance. When the temperature reached 220 °C, the NO conversion of ordered mesoporous CuSO4/CeWTiOx (CuCWT-OM) catalyst reached about 90 %. Introduce 100 ppm SO2 17.5 h under 260 °C, the conversion of CuCWT-OM catalyst can keep the above 80 %. The introduction of CuSO4 increased the acidity of CWT-OM catalyst, inhibited the sulfate formed by the reaction of SO2 with active species, and ensured the number of active sites in the reaction. In addition, the Cu-Ce interface effect accelerates the electron transfer frequency between the active species, stimulates the production of adsorbed NO2, and promotes the conversion of NO at low temperature. Furthermore, the interface confined effect and the framework confined effect make the active species Cu and Ce firmly confined in the ordered mesoporous framework structure, and reduce the action of SO2 on the active components. In addition, SO42− is more likely to react with W species, protecting the main active species Ce and inhibiting its acidification. This work provides a new feasible idea for improving the low temperature activity and anti-SO2 poisoning stability of Ce based catalyst.

Impact of geopolymer aggregate on the mechanical properties and durability characteristics of concrete

This study examined the use of geopolymer aggregate (GPA), produced from slag and an alkaline solution, as a substitute for coarse aggregate in conventional concrete. The research aimed to evaluate how different proportions of GPA (25%, 50%, 75%, and 100% replacement) affect the durability and mechanical properties of concrete. A series of tests were conducted, including slump, compressive strength, flexural strength, chloride resistance, sulfate resistance, sorptivity, and water absorption. The results demonstrated significant improvements in concrete properties with the inclusion of GPA. The compressive strength of GPA concrete ranged from 31 to 38 MPa, showing a 10%–15% increase over that of standard concrete. Flexural strength improved by 6% at 7 days and 7.5% at 28 days compared to control mixes. Water absorption was reduced by 42.58%, and sorptivity decreased by 47.9% compared to ordinary aggregate concrete. GPA concrete also excelled in acid resistance, with a weight loss of 28.6% and a lower reduction in strength compared to traditional acidic aggregates. In sulfate resistance tests, GPA concrete showed a 31% reduction in both weight and strength loss. These results highlight the advantages of using GPA as an alternative to conventional coarse aggregates. GPA not only enhances the mechanical and durability properties of concrete but also presents a more sustainable option, contributing to reduced environmental impacts associated with traditional aggregate materials.

Epistasis and cryptic QTL identified using modified bulk segregant analysis of copper resistance in budding yeast.

Most traits of interest that vary in populations are determined by multiple genetic factors, as well as by environmental variation and random chance. These influences may combine in complicated ways, for example when the effect of one genetic variant depends on genetic variants elsewhere in the genome. Such dependencies are difficult to identify and characterize because testing many possible combinations of influences reduces statistical power. We address this challenge by combining bulk segregant analysis, a robust method for detecting effects of individual genetic variants averaged across genetic backgrounds, with chromosome fixation in budding yeast. This approach allows us to detect gene-variant effects that depend on the fixed chromosome with statistical power comparable to that achieved when detecting background-independent effects. Applying the approach to copper sulfate resistance, we identify and characterize interaction effects and, by removing one source of variation (a single yeast chromosome), improve detection of background-independent effects as well.

Unveiling Improved Sulfate Resistance of high-performance Concrete Composites Using Maize cob ash Particles and Raffia Fibers

Unveiling Improved Sulfate Resistance of high-performance Concrete Composites Using Maize cob ash Particles and Raffia Fibers

Enhancing the resilience of cement mortar: Investigating Nano-SiO2 size and hybrid fiber effects on sulfuric acid resistance

This article explores fortifying cement mortars against severe sulfuric acid (SLA) attacks by studying the impact of nano-SiO2 (NS), macro-steel (ST), and micro-polypropylene (PP) fibers. The aim is to assess their effects on workability, physical attributes, mechanical properties, and durability against SLA attacks when incorporated into mortar blends. Replacing 1 % of cement weight with NS, having average particle diameters of 15 nm (nm) (NS15) and 55 nm (NS55), and utilizing macro-ST and micro-PP fibers at volumes of 0.5 % and 1 % in singular and hybrid forms resulted in significant changes in mortar characteristics. While these additives increased fresh mortar viscosity and negatively affected workability, they substantially boosted mortar strength and durability against SLA attacks. The most substantial improvements were observed using smaller NS particle sizes and employing hybrid ST/PP fibers. The formation of calcium-silicate-hydrate (C-S-H) bonds by NS within the network emerged as a pivotal factor. NS's high pozzolanic activity and void-filling capacity significantly enhanced the mortars' strength and durability against SLA attacks. Furthermore, instead of their singular application, the combined use of ST and PP fibers proved more effective in restraining micro and macro cracks within the mortar matrix. The bridging effect of hybrid ST/PP fibers delayed crack propagation throughout the network, highlighting their superior efficiency against SLA attacks.Overall, these findings hold promise for designing cement-based composites resilient to harsh, acidic environments. Using smaller NS particles and hybrid fiber combinations presents potential pathways to prolong service life in challenging conditions.

Influence of limestone powder particle size on the sulfate resistance of cement-based materials under the coupling effect of time-varying temperature and sulfate attack

Replacing a portion of cement clinker with limestone powder can reduce carbon dioxide emissions, but limestone powder with different mixing rations and particle sizes will exert varying impacts on freshly mixed cement-based materials. In this paper, the effects of different limestone powders on the sulfate attack resistance of cement-based material under the coupling of time-varying temperature and sulfate attack are systematically investigated. At the same time, a variety of modern analysis and testing techniques were used to characterize the composition of erosion products during the coupling process of temperature time-varying and sulfate attack. Additionally, a full-life reliability of cement-based materials with limestone powder was evaluated by Weibull distribution. And the results showed that limestone powder with smaller particle size could reduce its impact on the sulfate resistance of cement mortar. The erosion products of samples were mainly ettringite and gypsum in the early stage, and the ettringite gradually changed to thaumasite in the later stage. The Weibull distribution can accurately simulate the reliability change of the specimen in the whole process, which can provide reference for future practical application in engineering.

Mechanical properties and sulfate resistance of basalt fiber-reinforced alkali-activated fly ash-slag-based coal gangue pervious concrete

To address the strength deficiencies and enhance the durability of coal gangue pervious concrete while promoting the resource utilization of coal gangue, this study employs alkali-activated fly ash and slag as binding materials, partially replacing natural coarse aggregates with coal gangue to prepare alkali-activated fly ash-slag-based coal gangue pervious concrete (AFSGPC). Basalt fibers are introduced to examine the effects of varying fiber lengths and volume fractions on the mechanical properties, permeability, and sulfate resistance of AFSGPC. Results indicate that incorporating an appropriate amount of basalt fibers improves the mechanical properties and sulfate resistance of AFSGPC, attributed to the high strength characteristics of the alkali-activated fly ash-slag binder and the crack-bridging and toughening effects of the basalt fibers, although it may slightly reduce permeability. When the fiber length is 12 mm and the volume fraction is 0.1 %, the compressive strength at 28 days reaches 24.12 MPa, and the splitting tensile strength is 2.95 MPa, reflecting increases of 10.48 % and 32.89 %, respectively. The permeability coefficient is measured at 2.07 mm/s, meeting the standards for pervious concrete in road applications. After undergoing 60 cycles of sulfate wet-dry erosion, the corrosion resistance coefficient of AFSGPC increases by 20.02 %. To meet the stringent strength requirements for pervious pavements, it is recommended that basalt fibers with a length of 12 mm and a volume fraction of 0.1 % be utilized in AFSGPC. In regions characterized by high precipitation, the application of basalt fibers shorter than 12 mm, with a volume fraction not exceeding 0.15 %, is advisable to minimize the obstruction of interconnected pores. These findings provide valuable insights for the preparation and engineering application of basalt fiber-modified AFSGPC.

Experiment and modelling of degradation mechanism of cement mortar with graphene oxide nanosheets under sulfate attack

Degradation of cementitious materials caused by sulfate attack poses a significantly challenge to their durability. Using nano-additives to enhance the mechanical and durability properties of cementitious materials is a promising solution; however, the impact of graphene oxide (GO) on the sulfate resistance is not yet fully understood. While efforts have been made to study the degradation mechanism through accelerated indoor tests with high sulfate concentrations, these methods fail to accurately replicate real-world field exposure conditions. To better understand the degradation mechanism of GO-modified mortars under actual field conditions, this study examines the long-term degradation (over 24 months) of GO-modified mortars exposed to sulfate solutions with varying concentrations: 0 % (reference), 2.1 % (field condition), 5 % (laboratory condition), and 15 % (high-concentration condition). Additionally, a comprehensive chemo-mechanical model that considers multiple factors and time-varying boundary conditions was proposed. The study thoroughly discusses the effects of GO dosage, sulfate concentration, and exposure time on the degradation mechanism. Comparison with experimental data revealed that cement mortar degradation under sulfate attack is primarily driven by the crystallization pressure related to ettringite formation in diluted sulfate solutions, while the precipitation of alkali ions from mortar pore solutions occurs in concentrated sulfate solutions. In real-field conditions, cement mortar degradation primarily involves gypsum precipitation rather than ettringite formation. This study demonstrates that well-dispersed GO nanosheets can significantly enhance durability of cementitious materials against sulfate attack, offering valuable insights for strategic applications of GO nanosheets in cementitious materials.

Exploring the impacts of liquid accelerators on sulfate resistance and calcium leaching behavior of wet-mixed shotcrete

The performance of shotcrete used in underground tunnel construction is often compromised by the challenging service environment, causing severe deterioration and structural integrity concerns. Developing high-quality accelerating agents can be a viable approach to mitigate this effect. This study formulates alkali-free fluorine-free (AF-I); alkali-free fluorine-containing (AF-II); and low-alkaline (AC) liquid accelerators and explores their impacts on sulfate resistance and calcium leaching behavior of shotcrete, utilizing semi-immersion and short-term tank water testing protocols on a time-resolved basis. Microstructural analysis of eroded shotcrete was conducted employing XRD, TGA and SEM to reveal underlying mechanisms. Additionally, ionic analyses of simulated leaching systems, including groundwater and 5 % sodium sulfate solution were performed using ICP-OES to monitor calcium activity and assess leaching behaviors. Results indicate that shotcrete accelerated with AF-II exhibits the strongest resistance, whereas shotcrete with AC suffers the severest deterioration. The primary deterioration mechanism of shotcrete with AC was majorly due to high ettringite and gypsum corrosion, whereas AF-I and AF-II induces little ettringite corrosion. In terms of leaching behavior, AF-II demonstrates superior calcium leaching mitigation, with leachability indices in groundwater and sodium sulfate solution measuring 0.06 and 0.19, and 0.02 and 0.16 higher values, respectively, compared to AF-I and AC. Findings of this study provide valuable insights into the application and performance of shotcrete in sulfate-prone environments, aiming to mitigate potential deterioration through optimal accelerator selection.

Sulfur-resistant mechanism of MnOx@CeO2@MgO core-shell catalyst in simultaneous removal of NOx and chlorobenzene

Herein, Mn-Ce based catalysts with different structures were rationally designed to explore their sulfur-resistant mechanism for simultaneous removal of NOx and chlorobenzene (CB) from waste incineration at low temperature. In the presence of SO2, MnOx@CeO2@MgO exhibits the highest sulfur resistance among prepared catalysts. Both NOx and CB conversion over MnOx@CeO2@MgO can reach up to 80 % at 300 °C. However, the significant deactivation is observed for MnCeMgOx within all temperature ranges. For the selectivity of products, MnOx@CeO2@MgO displays the excellent N2 selectivity (93 %) and good CO2 selectivity (80 %) at 300 °C. Compared with NO reduction, SO2 has a greater impact on CB destruction due to the consumption of reactive oxygen species during SO2 oxidation. The reduction of active oxygen is proposed to be the reason for the significant inhibition of CB oxidation. The addition of MgO shell increases the proportion of lattice oxygen, which is beneficial to improving the sulfur resistance of MnOx@CeO2@MgO catalyst. In addition, SO2 can react with MgO preferentially to protect the active sites and improve the sulfur resistance. This work indicates that MnOx@CeO2@MgO core-shell catalyst with good sulfur tolerance and stability is expected to be applied in the potential application.

Machine Learning Accelerated Discovery of Entropy-Stabilized Oxide Catalysts for Catalytic Oxidation.

The catalytic properties of unary to ternary metal oxides were already well experimentally explored, and the left space seems like only high entropy metal oxides (HEOs, element types ≥5). However, the countless element compositions make the trial-and-error method of discovering HEO catalysts impossible. Herein, based on the study of the crystal phase and catalytic performance of the ACr2Ox catalyst system, the strong correlation between the single spinel phase and good catalytic activity of CH4 oxidation was inferred owing to the similar element importance sequences, which were acquired by the corresponding high accuracy machine learning models (cross-validation score >0.7). Furthermore, searching for negative data and choosing the proper training data resulted in high-quality regression models to search for better catalysts. Finally, the screened irregular catalyst Ni0.04Co0.48Zn0.36V0.12Cr2Ox with outstanding sulfur and moisture resistance and long-term stability (>7000 h, T90 = 345 °C) envisions the potential of applying the machine learning method to discover HEOs for target processes.

Sulfate attack on portland-dolomite cement exposed to sodium sulfate solution at 5 ℃ and 20 ℃

The purpose of the study is to investigate the sulfate resistance of portland-dolomite cement (PDC) with varying dolomite contents, when exposed to sodium sulfate solution at 5 ℃ and 20 ℃. Visual appearance, expansion, mass change, and compressive strength of PDC mortars were tested, and XRD, FTIR, and SEM analyses were conducted to examine deterioration products and microstructure. Results indicate that at 20 ℃, the incorporation of 10 % dolomite in PDC had a negligible impact on sulfate resistance, whereas higher dolomite replacements of 20 % and 30 % notably diminished it. In contrast, exposure at 5 °C led to more severe deterioration in all PDC samples, regardless of dolomite content, and the higher dolomite content, the poorer resistance to sulfate attack. The increased formation of ettringite and gypsum resulted in reduced sulfate resistance of PDC at 20 ℃. However, at 5 ℃, the presence of dolomite significantly promoted the formation of thaumasite at later stages, which caused initial ettringite and subsequent late-stage thaumasite sulfate attack, ultimately leading to the failure of PDC. The findings suggest that PDC should be carefully considered when used in sulfate-rich environments, particularly at low temperatures.