Sulfate Type Research Articles

Thermodynamic modeling and phase diagram prediction of salt lake brine systems II. Aqueous Li+-Na+-K+-SO42− and its subsystems

Predicted result of complete structure phase diagram of Li 2 SO 4 -Na 2 SO 4 -H 2 O system at temperature ranging from eutectic point 251.19–373.15 K: P1, P2, P3, P4, P5 are Transition points of three solid co-saturated in the ternary system. • Thermodynamic model of aqueous Li+-Na+-K+-SO 4 2− systems across entire temperature range. • Predicting the polythermal full structure phase diagram of ternary and quaternary aqueous system.. • The multi-objective optimization method to obtain solid constants and liquid parameters. It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component, multi-temperature and high concentration. The essential subsystem of sulfate type brine, aqueous Li + -Na + -K + -SO 4 2− and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model. Liquid parameters ( Δ g IJ , Δ h IJ , and Δ C p , I J ) associated with the contributions of Gibbs energy, enthalpy, and heat capacity to the binary interaction parameters, i . e . the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression, are determined via multi-objective optimization method. The solid constants Δ f G k ° ( 298.15 ) and Δ f H k ° ( 298.15 ) of 11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities. The modeling results show the accurate representation of (1) solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K; (2) isothermal phase diagrams for Li 2 SO 4 -Na 2 SO 4 -H 2 O, Li 2 SO 4 -K 2 SO 4 -H 2 O and Na 2 SO 4 -K 2 SO 4 -H 2 O ternary systems. The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.

Properties of the Cement Paste Mixed with Various Types of Aluminum Sulfate Based Liquid Alkali-Free Accelerator

In this paper, the effects of various components in alkali-free accelerator on the setting of cement paste were studied, and the morphology of the hydrates during hydration was investigated with SEM. The experimental results show that the aluminum sulfate, diethanolamine and hydrofluoric acid can effectively shorten the setting time of cement paste, while excessive dosage has minimal impacts on the setting time. The diethanolamine and hydrofluoric acid can not only shorten the setting time but also can improve the stability of the accelerator. It was evidenced by the SEM that the aluminum sulfate accelerates cement coagulation by quickly forming a large amount of ettringite in the cement paste. The results in this study suggest that the shortest setting can be achieved when the dosage of aluminum sulfate, diethanolamine and hydrofluoric acid in a liquid alkali-free accelerator is 57 %, 5 % and 5.7 % , respectively.

Skeletal muscle myosin and cardiac myosin attenuate heparin's antithrombin‐dependent anticoagulant activity

BackgroundHeparin enhances the ability of the plasma protease inhibitor, antithrombin, to neutralize coagulation factor Xa and thrombin. Skeletal muscle myosin binds unfractionated heparin. ObjectivesThe aim of this study was to investigate the influence of myosin binding to heparin on antithrombin's anticoagulant activity. MethodsInhibition of factor Xa and thrombin by antithrombin in the presence of different heparins and skeletal muscle myosin or cardiac myosin was studied by measuring inhibition of each enzyme's chromogenic substrate hydrolysis. Results and ConclusionsSkeletal muscle myosin and cardiac myosin neutralized unfractionated heparin's enhancement of antithrombin's inhibition of purified factor Xa and thrombin. Skeletal muscle myosin also reduced the inhibition of factor Xa and thrombin by antithrombin in the presence of heparan sulfate. These two myosins did not protect factor Xa from antithrombin inhibition when tested in the presence of smaller heparins (eg, low molecular weight heparin, heparin pentasaccharide). This chain length dependence for skeletal muscle myosin's ability to reduce heparin's anticoagulant activity might have potential implications for therapy for patients who experience increases in plasma myosin levels (eg, acute trauma patients). In addition to the chain length, the type and extent of sulfation of glycosaminoglycans influenced the ability of skeletal muscle myosin to neutralize the polysaccharide's ability to enhance antithrombin's activity. In summary, these studies show that skeletal muscle myosin and cardiac myosin can influence antithrombin's anticoagulant activity against factor Xa and thrombin, implying that they may significantly influence the hemostatic balance involving bleeding vs clotting.

Fluid geochemistry and isotope compositions to delineate physical processes in Wayang Windu geothermal reservoir, Indonesia

Wayang Windu geothermal field, which is situated in quaternary volcanic rock, has been delivering 227 MW of electricity and is planned to be developed in near future. Isotope and geochemistry study has been done to support understanding of the system. Samples were taken from thermal manifestations and production wells (two-phase and dry steam wells) to analyse its isotope and chemical compositions. Most of the hot springs are bicarbonate type and have neutral pH values, except for steam heated waters found near fumarolic fields, which are acid sulfate type waters. Deep brine fluids are of mature chloride type, while other deep dilute fluids are bicarbonate type indicates the existance of condensate layer. Solute and gas geothermometer calculation showed good agreement with measured temperature, i.e., 280–300 °C. However, gas-gas equilibria calculation showed increasing T and decreasing y (steam fraction) compare to previous study which indicates contribution form hotter source with high liquid saturation. Aside from different recharge area of thermal manifestation and production wells, the isotopes composition also shows physical processes in reservoir, i.e., adiabatic boiling, steam separation at different temperature (140–260 °C) and steam fraction (0.30–0.65), and also mixing process with meteoric water.

Hydrochemistry Differences and Causes of Tectonic Lakes and Glacial Lakes in Tibetan Plateau

The Tibetan Plateau has the largest lake cluster in China and in the world. In order to clarify the differences of lake hydrochemistry of Tibetan Plateau, water samples were collected from 32 lakes, including 22 tectonic lakes and 11 glacial lakes, along the Tibetan Plateau road, from September to October 2016. We detected and analyzed the major ion concentrations and characteristics of samples, and discuss the hydrochemistry type, controlling factors, and major ion sources of lake water. The results showed that, firstly, tectonic lake samples on the Tibetan Plateau have much higher physicochemical parameters and ion contents than glacial lakes, and Total Dissolved Solids (TDS) contents fluctuate from high to low latitudes. The variations of ion concentrations in the northern part of the Qiagui Co were more fluctuating and have two obvious peaks, while the variations in the southern part were moderate. The TDS of glacial lakes were low and leveling off in the upper and middle reaches of the basin, while higher and more variable in the lower reaches. Secondly, the tectonic lakes were mainly chloride saline lakes, with Na+ as the major cation, and SO42−, Cl− as the major anions. Glacial lakes were mainly carbonate and sulfate type lakes, Ca2+ and Mg2+ were the major cations, HCO3− was the major anion, and SO42− was the second. Thirdly, the hydrochemistry processes of the tectonic lakes were mainly controlled by evaporation-crystallization, and the ions mainly came from the evaporites of basin. Glacial lake water samples were mainly influenced by the weathering of basin rocks, with ion sources strongly influenced by the weathering of basin carbonates than evaporites, with calcite and dolomite being important sources of Ca2+, Mg2+, and HCO3−.

Effects of Sulphates on the Characteristics of Ordinary Portland Cement

This project presents the results of an experimental investigation in which the effects of sulphates on the initial and final setting times of ordinary Portland cement and compressive strength of cement is investigated. It was observed that the type of Sulphate and the ion concentration affect the setting times significantly; the increase in initial setting time is more prominent. The parameters reduce the compressive strength of cement at different ages. In the present study water cement ratio is taken depending on the normal consistency arrived based on different concentrations of sulphates mixed with OPC (Ordinary Portland Cement) an increase in setting times is observed as the concentration of sulphates in the cement paste increased. The soundness test results also showed an increased pattern which means that there is an increase in volume of cement paste because of sulphate attack. Compressive strength characteristics also showed an increased pattern when compared to cubes cast with distilled water

Geochemical Exploration of Geothermal Manifestations: Study Case of Bajawa Volcanic Complex, Flores Island, East Nusa Tenggara Province

Currently Indonesia occupy third place in the World demand of geothermal energy with using of 1375 Mwe (Mega Watt electrical). Energy utilization is only used around 4 – 5 % of geothermal energy capacity owned by Indonesia. Surely, this fact encourages many researcher to develop geothermal field with multidisciplinary sciences. One of potential geothermal areas is Nage geothermal field located in Bajawa City, Ngada District, East Nusa Tenggara Province. Four hot springs and fumarole were founded in the area. The Exploration using geochemical analysis in the form of descriptive method and analysis of geothermal fluid data. Based on regional geology, Bajawa volcanic complex composed of three periods of volcanic, first is old volcanic that formed Nage Caldera and Old Inierie volcanoes, then formed Bajawa Cinder Cone unit with North – South and North East – Southwest alignment, this alignment surely controlled as a linear eruptions. And the last is Inierie unit, this unit is active stratovolcano. The results of data obtained from one fumarole and four hot springs sample were taken from Wolo puti fumarole, Bena hotspring, Keli hotspring, Nage I hotspring and Nage II hotspring. Based on the relationship of chemical element ratio and plotting of triangular Giggenbach diagram shows that Keli and Bena hot springs are sulphate type, this hotspring controlled by Wolo puti fumarole as upflow of the geothermal system then Keli and Bena hot springs are in the outflow zone, which has mixed by meteoric water. Nage I and Nage II hot springs are chloride type, which has different geothermal system from Keli and Bena hot springs. Based on the geothermometer calculation of the Na-K-Mg diagram, the temperature of reservoir is 220° - 340° C, which is included of high enthalpy geothermal system.

Investigation of the effects of different sulfate types found in seawater on concrete containing microfiber and silica fume

Sulfate salts which available in seawater with high concentrations cause the formation of ettringite in hydrated structures which formed as a result of the hydration of cement. On the other hand, ettringite causes excessive volume expansions and eventually leads to cracking of the concrete due to the internal stresses in concrete since it is a large volume mineral structure. In this study, ultrafine cement and silica fume as mineral additive were used together for binder design. Besides, microfiber has been added to the binder systems produced in different proportions. The produced specimens were kept separately in water, in solutions containing 2% Na2SO4 and 2% MgSO4 by weight for 90 days. The compressive strength test was performed at 28th and 90th days on cured specimens. In addition to the compressive strength test, the solution samples were taken from the curing solutions every 10 days and the change of sulfate concentrations was followed in the solutions. According to the results, in Na2SO4 solution higher compressive strength values were observed up to 66 MPa while strength loss was observed in the specimens cured in the MgSO4 solution. In parallel to this result, the remaining concentrations of SO42- ions in the MgSO4 solution were lower than those in the Na2SO4 solution. It was inferred that in Na2SO4 solution, the fibers could compensate for the internal stresses. This situation shows that especially the microfiber additive can compensate for the expansion that will occur as a result of ettringite formation, and thus it can help the mechanical stability of the concrete.

Influence of cement with different calcium sulfate phases on cementitious tile adhesive mortars: Microstructure and performance aspects

Cement is generally used as a mineral binder in construction materials. The components formed as a result of the reaction between cement and water give physical strength to construction products. This reaction is influenced by the mineralogical composition of the cement. The clinker composition does not vary greatly for ordinary Portland cement. However, the calcium sulfate composition may vary from manufacturer to manufacturer, and even from batch to batch, depending on the effect of heat dissipation during the process of grinding the clinker with calcium sulfate. The type of calcium sulfate affects the hydration reaction and performance properties of cementitious tile adhesive (CTA). In this study, the hydration behavior and performance of CTA samples prepared from cement containing different calcium sulfate forms were investigated. The developed microstructures were characterized by scanning electron microscope (SEM), X-ray diffractometer (XRD), and calorimeter, while the performance was tested according to EN 12004 standards.

Особенности ионно-солевого состава подземных вод венд-нижнекембрийских отложений Среднеботуобинского нефтегазоконденсатного месторождения на стадии катагенеза

The salt water omposition of underground brines of the Vendian - Lower Cambrian sections of the Middle Botuoba oil-gas-condensate field during the catagenesis stage is considered; the peculiarity of which is the presence of polygenic waters in certain block traps of B5 and Б1 levels: sodium sulfate, sodium hydrogencarbonate and chlorine-magnesium genetic types together with the prevailing chlorine-calcium genetic type. The zoning of the groundwater of the strata by mineralization and four genetic types of groundwater has been carried out. The directions of water entry into the reservoirs formed at the stage of catagenesis and entering together with hydrocarbons in the corresponding traps are established. It is shown that, while maintaining the mechanism of formation of the salt water composition in the "rock-water" system, the polygenicity of the formation waters present simultaneously in one reservoir layer reflects a regular change in the components of their chemical composition during the transition from the artesian basin to the oil and gas basin. The most sensitive ions of the chemical composition of groundwater, reflecting the transition of the artesian basin to the new geological state of the catagenesis stage, are sulfate, bicarbonate, and sodium ions.

Syndecan-1 Promotes Hepatocyte-Like Differentiation of Hepatoma Cells Targeting Ets-1 and AP-1

Syndecan-1 is a transmembrane heparan sulfate proteoglycan which is indispensable in the structural and functional integrity of epithelia. Normal hepatocytes display strong cell surface expression of syndecan-1; however, upon malignant transformation, they may lose it from their cell surfaces. In this study, we demonstrate that re-expression of full-length or ectodomain-deleted syndecan-1 in hepatocellular carcinoma cells downregulates phosphorylation of ERK1/2 and p38, with the truncated form exerting an even stronger effect than the full-length protein. Furthermore, overexpression of syndecan-1 in hepatoma cells is associated with a shift of heparan sulfate structure toward a highly sulfated type specific for normal liver. As a result, cell proliferation and proteolytic shedding of syndecan-1 from the cell surface are restrained, which facilitates redifferentiation of hepatoma cells to a more hepatocyte-like phenotype. Our results highlight the importance of syndecan-1 in the formation and maintenance of differentiated epithelial characteristics in hepatocytes partly via the HGF/ERK/Ets-1 signal transduction pathway. Downregulation of Ets-1 expression alone, however, was not sufficient to replicate the phenotype of syndecan-1 overexpressing cells, indicating the need for additional molecular mechanisms. Accordingly, a reporter gene assay revealed the inhibition of Ets-1 as well as AP-1 transcription factor-induced promoter activation, presumably an effect of the heparan sulfate switch.

The influence of Si/Al ratio on sulfate durability of metakaolin-based geopolymer

The durability of geopolymers in sulfate is essential to their application in harsh environments. In this paper, the influence of Si/Al ratio, one of the major composition parameters of metakaolin-based geopolymer (MKG), on its durability in both sodium and magnesium sulfate solutions was investigated in detail. The results indicate there is a strong coupling effect appears between Si/Al ratio and the sulfate type. The ion exchange process of MKG with different Si/Al ratios is significantly influenced by the cation of sulfate. The exchange of OH− and SO42− dominates the ion exchange process in sodium sulfate solution while the exchange of Na+ and Mg2+ dominates in magnesium sulfate solution. In addition, the variation of strength, chemical structure, micromorphology in two sulfate environments is also closely dependent on Si/Al ratio. The Si/Al ratio shows notable influence on micromorphology and strength in magnesium sulfate solution while there is negligible influence of Si/Al ratio in sodium sulfate solution.

Dissolution and early hydration of tricalcium aluminate in aqueous sulfate solutions

The great reactivity of tricalcium aluminate (C3A) with water and subsequent rapid precipitation of insoluble products are serious challenges to learning how salts affect its interfacial chemistry and physics during dissolution. Those challenges are addressed here with rapid in situ surface nanotopography monitoring and characterization of hydration products as C3A dissolves in aqueous sulfate solutions (Na2SO4, MgSO4, and CaSO4) with varying pH. These measurements shed light on how pure dissolution and early hydration of C3A are influenced by sulfates. Bulk dissolution experiments confirm a cation-specific effect of sulfates on the inhibition of C3A dissolution and of etch pit evolution. Soon after the initial contact with sulfate solutions, precipitation of hydration products occurred and the morphology and composition of products were strongly affected by the types of sulfates.

Durability of phosphogypsum-based supersulfated cement mortar against external attack by sodium and magnesium sulfate

Supersulfated cements (SSCs) are composed primarily of blast furnace slag, calcium sulfate, and a small content of alkaline activator. SSC has been discussed in the literature because it has a low content of clinker and consequently low CO2 emissions. However, the current absence of durability studies is the main challenge for the large-scale implementation of SSC as a building material. The objective of this study was to investigate the behavior of phosphogypsum-based SSC mortar under sulfate attack. SSC mortars were submitted to MgSO4 and Na2SO4 solutions. Portland cements were also used as a comparison. SSC mortar showed good durability against sodium sulfate attack but presented an expansive behavior when exposed to magnesium sulfate. This behavior in the MgSO4 solution was attributed to the low portlandite reserve, which anticipated the attack of C-S-H. Besides, the non-formation of the brucite layer accelerated the entry of this type of sulfate.

Geochemical characterization of groundwater evolution south of Grand Canyon, Arizona (USA)

Better characterization of the geochemical evolution of groundwater south of Grand Canyon, Arizona (USA), is needed to understand natural conditions and assess potential effects from breccia-pipe uranium mining in the region. Geochemical signatures of groundwater at 28 sampling locations were evaluated; baseline concentrations for select trace elements (As, B, Ba, Cr, Li, Mo, Rb, Se, Sr, Th, Tl, U, V) were established, and anomalous chemistry characteristics were identified. Concentrations at some groundwater sites exceeded the USEPA drinking water standard for As of 10 μg/L (Red Canyon, Miners, JT, Havasu, and Warm Springs) and U of 30 μg/L (Salt Creek Spring). Four springs from the study area (Blue, Havasu, Fern, and Warm Springs) had unique chemistry, which may indicate a deep flow path or potential contribution of fluids from lower in the crust. Other springs in the study area were distinguished by major anion water type: sulfate, bicarbonate, and a mixture of the two. Water type distinctions were somewhat spatially segregated, with sulfate type present on the western side of the study area, bicarbonate type on the eastern side, and a mixture of the two interspersed between the endmember sites. Sulfate-type water from this study area had low strontium isotopic ratio (87Sr/86Sr) values. The location of spring discharge within single drainages of the Grand Canyon may influence chemistry, as groundwater discharging from bedrock was altered after flowing through alluvial material. Geochemical analysis of groundwater in Grand Canyon indicates the importance of continued monitoring and better understanding of short-term chemical fluctuations.

Isotope and Geochemistry Characterization of Hot Springs and Cold Springs of Sembalun – Rinjani Area, East Lombok, West Nusa Tenggara – Indonesia

The presence of several hot springs in Sembalun – Rinjani, East Lombok, West Nusa Tenggara is an indicator of geothermal potential in the area. This study aims to determine the characteristics of hot springs and cold springs and also the geothermal potential in Sembalun – Rinjani area using isotopes and geochemistry methods. The result of d18O and d2H stable isotopes analysis shows that most of the hot springs are meteoric water. Except for Kalak hot spring, other hot springs are a mixing product of meteoric water and andesitic water, with meteoric water composition between 64 to 87%. While 14C radioisotope suggests that the age of hot springs in the Sembalun area is about 10,000–12,000 years BP, the surrounding cold springs are mostly Modern except Jorong cold spring. The results of gas analysis (He, Ar, and Ne) also suggest the same origin of geothermal fluid, i.e., meteoric water origin. Based on chemical composition, Kalak hot spring is plotted as sulfate type water, while Sebau hot spring is plotted near mature water composition but not representing reservoir fluid due to its relatively low temperature and high Mg content. Na/K geothermometer calculation from Sembalun area shows that subsurface temperature is varied between 111-161 °C, while from Rinjani hot springs indicates higher subsurface temperature, i.e., 250-260 °C. It is estimated that reservoir fluid has high TDS with chloride content up to 4000 mg/L.

Contribution of calcium aluminates to the water resistance of hydrated calcium sulfates

The water sensitivity of calcium sulphate materials has been known for a long time. In a humid atmosphere, plaster elements can become veiled under the action of their own weight because a low water uptake of 3% by mass can cause a drop in compressive strength of 50%. The low water resistance of calcium sulfates limits the applications of these materials to decorative elements or interior coatings despite their strengths compared to other construction materials: good fire resistance, low CO2 emission and low production cost. The objective of our research work is to evaluate the insensitivity of calcium sulfates to water by ettringitic binders containing calcium aluminate cement (CAC). Four types of calcium sulfates have been studied: natural gypsum, hemihydrate-α, hemihydrate-β, and synthetic anhydrite. In this research, only the majority binders of calcium sulfates will be studied: [70%, 80% of Calcium sultates with 30%, 20% of CAC]. The experiments results have shown that in high-calcium sulphate binders (≥ 70%), CAC helps reduce the water sensitivity of binders regardless of the nature of calcium sulphate by decreasing the total porosity, which leads to an increase in mechanical strengths; and reducing the connectivity of the pores, which contributes to reducing the entry of water and its movements into the material and consequently, reducing the degradation of the test pieces during immersion tests in the water.

Odiparcil, a potential glycosaminoglycans clearance therapy in mucopolysaccharidosis VI-Evidence from in vitro and in vivo models.

Mucopolysaccharidoses are a class of lysosomal storage diseases, characterized by enzymatic deficiency in the degradation of specific glycosaminoglycans (GAG). Pathological accumulation of excess GAG leads to multiple clinical symptoms with systemic character, most severely affecting bones, muscles and connective tissues. Current therapies include periodic intravenous infusion of supplementary recombinant enzyme (Enzyme Replacement Therapy–ERT) or bone marrow transplantation. However, ERT has limited efficacy due to poor penetration in some organs and tissues. Here, we investigated the potential of the β-D-xyloside derivative odiparcil as an oral GAG clearance therapy for Maroteaux–Lamy syndrome (Mucopolysaccharidosis type VI, MPS VI). In vitro, in bovine aortic endothelial cells, odiparcil stimulated the secretion of sulphated GAG into culture media, mainly of chondroitin sulphate (CS) /dermatan sulphate (DS) type. Efficacy of odiparcil in reducing intracellular GAG content was investigated in skin fibroblasts from MPS VI patients where odiparcil was shown to reduce efficiently the accumulation of intracellular CS with an EC50 in the range of 1 μM. In vivo, in wild type rats, after oral administrations, odiparcil was well distributed, achieving μM concentrations in MPS VI disease-relevant tissues and organs (bone, cartilage, heart and cornea). In MPS VI Arylsulphatase B deficient mice (Arsb-), after chronic oral administration, odiparcil consistently stimulated the urinary excretion of sulphated GAG throughout the treatment period and significantly reduced tissue GAG accumulation in liver and kidney. Furthermore, odiparcil diminished the pathological cartilage thickening observed in trachea and femoral growth plates of MPS VI mice. The therapeutic efficacy of odiparcil was similar in models of early (treatment starting in juvenile, 4 weeks old mice) or established disease (treatment starting in adult, 3 months old mice). Our data demonstrate that odiparcil effectively diverts the synthesis of cellular glycosaminoglycans into secreted soluble species and this effect can be used for reducing cellular and tissue GAG accumulation in MPS VI models. Therefore, our data reveal the potential of odiparcil as an oral GAG clearance therapy for MPS VI patients.

Prediction of mechanical and penetrability properties of cement-stabilized clay exposed to sulfate attack by use of soft computing methods

Similar to its effects on any type of cementitious composite, it is a well-known fact that sulfate attack has also a negative influence on engineering behavior of cement-stabilized soils. However, the level of degradation in engineering properties of the cement-stabilized soils still needs more scientific attention. In the light of this, a database including a total of 260 unconfined compression and chloride ion penetration tests on cement-stabilized kaolin specimens exposed to sulfate attack was constituted. The data include information about cement type (sulfate resistant—SR; normal portland (N) and pozzolanic—P), and its content (0, 5, 10 and 15%), sulfate type (sodium or magnesium sulfate) as well as its concentration (0.3, 0.5, 1%) and curing period (1, 7, 28 and 90 days). Using this database, linear and nonlinear regression analysis (RA), backpropagation neural networks and adaptive neuro-fuzzy inference techniques were employed to question whether these methods are capable of predicting unconfined compressive strength and chloride ion penetration of cement-stabilized clay exposed to sulfate attack. The results revealed that these methods have a great potential in modeling the strength and penetrability properties of cement-stabilized clays exposed to sulfate attack. While the performance of regression method is at an acceptable level, results show that adaptive neuro-fuzzy inference systems and backpropagation neural networks are superior in modeling.

Behavior of mortars exposed to attack by sodium and magnesium sulfate

Mortars are subject to contact with aggressive agents from the environment. Sulfates are aggressive to the cement matrix, mainly due to the appearance of expansive reactions between these ions and hydrated products of the cement paste. This study aimed to analyze the behavior of mortars with two types of Portland cement, exposed to solutions with sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4). The following properties of mortars were evaluated during the exposure to sulfates (up to 42 days): linear variation, mass variation, and ultrasonic pulse velocity. The formation of a gel layer on the samples exposed to the MgSO4 solution was observed, associated with the formation of brucite (Mg(OH)2). This gel behaved as a protective barrier, reducing the ingress of sulfate ions. The intensity of changes in mortar properties was affected by the type of cement and the type of sulfate. Statistical analyzes were performed to support the analyses.