Hydromagnesite Research Articles

A novel lignin/inorganic salt composite filler of alkali lignin/basic magnesium carbonate for enhancing the hydrophobicity of polylactic acid composites

To enhance the hydrophobicity of polylactic acid (PLA) composite, a novel alkali lignin/basic magnesium carbonate (AL-BMC) was prepared by carbon dioxide carbonization method. The interaction forces between AL and BMC, the morphology of AL-BMC, and the effect of the additive amount of AL-BMC on the hydrophobicity of PLA/alkali lignin/basic magnesium carbonate (PLA/AL-BMC) composites were investigated. The results of Fourier transform infrared spectra, X-ray diffraction pattern, and scanning electron microscope showed that there were hydrogen bonds between AL and BMC, the morphology of AL-BMC composites showed a flower-like structure, and the aggregation of basic magnesium carbonate was effectively inhibited by the hydrogen bonds between AL and BMC. The water contact angles of PLA/AL-BMC significantly increased with the addition of AL-BMC. Specifically, when the additive amount of AL-BMC was 20 %, the water contact angle of PLA/AL-BMC was 97.4°, which was higher than that of PLA/AL by 57.1 %. Therefore, the hydrophobicity of PLA/AL were effectively enhanced by the addition of AL-BMC composite filler. This study presents a novel strategy for enhancement of the hydrophobicity of PLA composite, utilization of lignin, and conversion of carbon dioxide.

Basic magnesium carbonate template assisted co-carbonization of potassium citrate toward hierarchical porous carbon for supercapacitors

Hierarchical porous carbon (HPC) as the ideal host material for supercapacitors has received extensive attention. However, traditional methods of fabricating HPC often rely on organic macromolecules and complex procedures. Herein, a simple and straightforward approach is developed for the synthesis of HPC through basic magnesium carbonate template assisted co-carbonization of potassium citrate. Potassium citrate can be effectively embedded and encapsulated with basic magnesium carbonate due to the large bulk density difference between them. In the pyrolysis process, the carbon-containing small molecules produced by the pyrolysis of potassium citrate are deposited on the surface of MgO surface obtained from the decomposition of basic magnesium carbonate, and the etching reaction of potassium salt, CO2 and primary carbon structure occurs. The competitive rate of carbon deposition reaction and etching reaction can be easily controlled by changing the ratio of potassium citrate and basic magnesium carbonate. The obtained carbon materials show the morphology changes of nanoparticle accumulations, discontinuous carbon frames and carbon planar blocks, and the hierarchical porous structure of carbon materials can also be controlled in a wide range. HPC-2 exhibits the morphology of nanoparticle accumulation and generates abundant meso-macropores, which accelerates the rapid transport of electrolytic ions. The micropores inside the nanoparticles provide an accessible room for ionic adsorption. Benefited from this unique microstructural framework, HPC-2 shares a high capacitance of 305.5 F g−1 at 0.5 A g−1 and 173.1 F g−1 at 50 A g−1. Furthermore, the assembled symmetric supercapacitors exhibit a high energy density and power density than YP-50 F throughout the test range. The versatility of this synthetic strategy provides an insight into directional tailoring fine pore structure and micro-morphology of carbon materials based on small molecule deposition.

Study on the mechanism of controlling the morphology of basic magnesium carbonate prepared under different hydration conditions

Basic magnesium carbonate is gaining prominence in flame retardant materials due to its excellent flame-retardant properties and clean decomposition products. This study investigates a hydration-carbonation method to address challenges related to the preparation, morphology control, and stability of magnesium basic carbonate. The impact of hydration conditions on the morphology of the carbonate was analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicate that spherical magnesium basic carbonate with regular morphology and uniform particle size can be achieved at a hydration temperature of 50°C for 1.5 hours. However, extending the hydration time and increasing the temperature resulted in irregular morphologies. Molecular dynamics simulations using the CASTEP and Forcite modules of Materials Studio were employed to understand the influence of hydration-carbonation conditions on the carbonate's morphology. The simulations revealed that the (1 1 1) and (2 0 0) crystal faces of MgO, with higher surface energies, promote the formation of precursor magnesium hydroxide nuclei, leading to heterogeneous magnesium alkali carbonate at elevated temperatures. Prolonged hydration time resulted in fragmented carbonate structures. To control the morphology of magnesium alkali carbonate, it is essential to optimize hydration temperature and duration. The simulation results corroborate experimental findings, providing deeper insights into the liquid-gas-solid adsorption relationships during the carbonation process. This study offers valuable guidelines for the controlled synthesis of magnesium basic carbonate, enhancing its applicability in flame retardant materials.

Synthesis of Magnesium hydroxide Whisker‐encapsulated Carbonized Chitosan and Basic Magnesium Carbonate Composite for Efficient Pb(II) Removal

AbstractIn this study, for magnesium hydroxide adsorbents, hydrothermal doping strategies were used to change their surface and structural properties to enhance adsorption. A novel adsorbent was prepared and used to remove low concentrations (<100 mg ⋅ L−1) of Pb2+ from water. The structure of the adsorbent was characterized a series of characterization methods with X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, fourier transform infrared spectroscopy, nitrogen adsorption‐desorption isotherms, and X‐ray photoelectron spectroscopy. The results showed that the adsorbent was a whisker composed of magnesium hydroxide, carbonized chitosan and basic magnesium carbonate (BMC@Mg(OH)2/CCS) with a specific surface area of 84.35 m2 ⋅ g−1, much higher than that of pure magnesium hydroxide whisker (37.84 m2/g). The adsorption isotherm, kinetic, and thermodynamic properties of the adsorbent for lead ions were studied in detail by batch adsorption. The Langmuir model fits the adsorption isotherm better, and the adsorption capacity is 416.67 mg ⋅ g−1. The adsorption mechanism, which mainly involves chemical precipitation and ligand chelation, is discussed.

The computer quantum chemical modeling of basic magnesium carbonate stabilized by biopolymers

The computer quantum chemical modeling of basic magnesium carbonate stabilized by biopolymers

Development of the Composition and Technology of Capsules Containing Peony Evadiant Rhizomes and Roots Dry extract and Glycine

Introduction. The development of dosage forms of sedative action is an urgent task of pharmaceutical technology in view of the prevalence of diseases of the nervous system. Peony rhizomes and roots dry extract in combination with glycine have a sedative and anxiolytic effect, which is associated with an improvement in the psycho-emotional state. Taking into account the physicochemical characteristics and composition of biologically active substances of peony rhizomes and dry extract roots, it is necessary to select auxiliary substances that improve its technological properties.Aim. Development of the composition and technology of hard gelatin capsules containing dry peony rhizomes and roots, dry extract and glycine.Materials and methods. Objects of research – dry peony rhizomes and roots (LLC "Kazan Extract Plant", Russia), glycine (JSC "Biokhimik", Russia). Excipients: apple pectin (LLC TD "HIMMED", Russia), starch (LLC TD "HIMMED", Russia), aerosil (LLC TD "HIMMED", Russia), lactose (LLC TD "HIMMED", Russia), microcrystalline cellulose (LLC TD "HIMMED", Russia), basic magnesium carbonate (LLC TD "HIMMED", Russia), magnesium oxide (LLC TD "HIMMED", Russia).Results and discussion. The composition and technology for obtaining capsules containing dry peony rhizomes and roots, dry extract and glycine, have been substantiated. The quality indicators of peony rhizomes and roots of dry extract in combination with glycine and developed capsules were determined.Conclusion. The composition of capsules of peony rhizomes and roots of dry extract and glycine has been developed, auxiliary substances have been selected to ensure satisfactory technological properties of the mass for filling the capsules.

The preparation and fire extinguishing mechanism research of a novel high-efficiency KHCO3 @HM dry powder

Hydromagnesite (HM) is a widely distributed primary natural carbonate mineral. To expand the application range of hydromagnesite and tap its fire-extinguishing potential, a new type of high-efficiency KHCO3 @HM dry powder was prepared by coating potassium bicarbonate on the surface of hydromagnesite with a dip coating method. KHCO3 @HM dry powder obtained a chemical inhibition effect through this method, and the fire extinguishing efficiency has been further improved. A series of tests were carried out to confirm the excellent physical and chemical inhibition effect of KHCO3 @HM dry powder. Specific surface area tests showed that the specific surface area of KHCO3 @HM dry powder (31.405 m2/g) was higher than NH4H2PO4 dry powder (12.766 m2/g). Flowability tests showed that KHCO3 @HM dry powder (0.04 g/s) achieved the same flowability as NH4H2PO4 dry powder (0.04 g/s). Local oil basin fire experiments showed that the average fire extinguishing time of KHCO3 @HM dry powder was shorter with less powder consumption. Under 0.2 MPa driving pressure, the fire extinguishing time of KHCO3 @HM dry powder was 2.2 s faster than NH4H2PO4 dry powder, and the dry powder consumption was 3.71 g less than NH4H2PO4 dry powder. The cooling effect of KHCO3 @HM dry powder (208 ℃) in 10 s was better than NH4H2PO4 dry powder (157 ℃), and KHCO3 @HM dry powder (399 ppm) showed a better smoke suppression effect than NH4H2PO4 dry powder (545 ppm). The pyrolysis of KHCO3 @HM dry powder reduced the fire temperature, diluted the oxygen concentration, and captured free radicals. The final pyrolysis products formed a thick oxide film to provide good heat insulation and asphyxiation effects. The excellent cooling, dilution, asphyxiation, and chemical inhibition mechanisms of KHCO3 @HM dry powder were demonstrated, and finally achieved a comprehensive performance comparable to NH4H2PO4 dry powder.

Characterization of solids obtained from calcium and magnesium precipitation by sodium carbonate addition

The addition of sodium carbonate (Na2CO3) to the flotation water of complex sulfide ores is a strategy implemented to mitigate the adverse effect of calcium and magnesium present in the process water of complex sulfide flotation. These contaminating agents are due to the use of lime as pH regulator and to the presence in the ore of magnesium species. Na2CO3 is added with the aim of precipitating Ca2+ and Mg2+ as carbonates. In the case of calcium, it precipitates CaCO3, which has been identified by XRD as calcite and vaterite. In the case of magnesium, the precipitating solid is of amorphous nature. In order to identify the chemical nature of magnesium precipitates, thermogravimetric analysis was carried out. Additionally, the solids were analyzed by SEM–EDS to support the observations. The results suggest that the amorphous solid may consist of a hydrated basic magnesium carbonate, precursor of hydromagnesite (Mg5(CO3)4(OH)2·4H2O).Graphical abstract

Preparation of basic magnesium carbonate nanosheets modified pumice and its adsorption of heavy metals.

Heavy metal pollution in wastewater poses a grave danger to the environment and the human body. Pumice is a mineral with abundant reserves and low prices, and its prospect of heavy metal adsorbent is very broad. In this work, we modified pumice with basic magnesium carbonate nanosheets by a convenient hydrothermal synthesis. The adsorption capacity of heavy metals is greatly improved. The effects of different pH and adsorption dosages are investigated. All the optimum pH values for Cu2+, Pb2+, and Cd2+ are 5. The adsorption of three kinds of ions conforms to the quasi-second-order adsorption kinetics model. The theoretical adsorption capacities of Cu2+, Pb2+, and Cd2+, which are calculated by the Langmuir model, are 235.29mg/L, 595.24mg/L, and 370.34mg/L, respectively. The adsorption of Cu2+ and Cd2+ fit the Langmuir model better. The Freundlich model is fitted well with the adsorption of Pb2+. In the experiment simulating real wastewater, the adsorption capacity of heavy metals is not affected. It also shows good reusability in three regeneration cycles. And Mg5(CO3)4(OH)2·4H2O@pumice adsorption column showed the good removal efficiency of three heavy metals at different concentrations and different spatial velocities in the column experiment. Thus, it is believed that the Mg5(CO3)4(OH)2·4H2O@pumice is a promising adsorbent for the efficient removal of heavy metals.

Study on the application of two magnesium salts in low temperature adsorption refining of fragrant rapeseed oil

Magnesium silicate and basic magnesium carbonate were characterized and their application in the low temperature adsorption refining of fragrant rapeseed oil was investigated. The results showed that both materials had a loose porous structure, but their particle size distribution, active functional groups, crystallinity, specific surface area, pore volume, and pore size differed. Under the optimal adsorption refining conditions, magnesium silicate and basic magnesium carbonate reduced the phospholipid content from 4.18 to 0.83 and 1.57 mg/g, acid value from 1.67 to 0.88 and 0.90 mgKOH/g, yellow value from 38.2 to 32.1 and 36.2, and red value from 2.9 to 1.7 and 2.2, respectively. The use of these two magnesium salts did not significantly alter the composition of fatty acids and the content of tocopherol. The retention rates of total phytosterol by magnesium silicate and basic magnesium carbonate were 93.6% and 95.9%, respectively. The retention rates of total phenol were 88.9% and 93.9%, respectively. The adsorption refining process proved to be advantageous in purifying fragrant rapeseed oil while maintaining the dominant flavor components relatively unchanged (P < 0.05). As a result, these two magnesium salts have the potential to be used during the low temperature adsorption refining process of fragrant rapeseed oil.

Hierarchical Ni/N/C Single‐Site Catalyst Achieving Industrial‐Level Current Density and Ultra‐Wide Potential Plateau of High CO Faradic Efficiency for CO2 Electroreduction

AbstractThe practical applications of CO2 electroreduction to CO driven by renewable electricity should simultaneously meet the requests of industrial‐level CO partial current density (JCO) at least 100 mA cm−2, wide potential window of high CO faradic efficiency (FECO), and low cost. Herein, a new strategy is reported to construct porous hierarchical Ni/N/C single‐site catalyst with excellent catalytic activity via coating Ni‐containing ZIF‐8 on mesostructured basic magnesium carbonate template followed by pyrolysis. The abundant micropores facilitate the formation of numerous edge‐hosted Ni‐N4 sites with high intrinsic activity, and the interconnected macro/mesopores much promote CO2 delivery and CO release for the full expression of intrinsic activity. Consequently, the catalyst exhibits the industrial‐level JCO of 105–462 mA cm−2 at the potential range of −0.6∼−1.3 V with ultra‐wide high FECO plateau (&gt;90%@−0.4∼−1.3 V), showing great promise for practical application. This study provides a general synthetic strategy to explore high‐performance hierarchical M/N/C electrocatalysts.

Flue gas torrefaction integrated with gasification based on the circulation of Mg-additive

Flue gas torrefaction (FGT) is a feasible way to improve fuel properties and enhance gasification performance. Torrefaction inevitably causes CO2 emissions. In this study, FGT integrated with gasification based on the circulation of Mg-additive (MgO-FGT-GS) was developed to capture CO2 released during FGT and transferred it to gasification to achieve a higher effective carbon conversion efficiency (ECC). Firstly, FGT with Mg-additive (MgO-FGT) was conducted on distilled spirits lees (DSL) and the effect of different Mg-additive (MgO) ratios was explored. Based on the characterizations of DSL and Mg-additive before and after MgO-FGT, the mechanism of MgO-FGT was revealed, and the looping property of Mg-additive was investigated. A fixed-bed gasification experiment was finally performed to validate the MgO-FGT-GS process. The results show that the optimal MgO-FGT was obtained as the MgO: DSL ratio was 1:1. Under this condition, the torrefied DSL had the highest HHV of 16.20 MJ/kg and the lowest O/C ratio. In MgO-FGT, the MgO absorbed 15.75 % of CO2 and changed into basic magnesium carbonate. Then in gasification, CO2 was released by Mg-additive at 800 ℃, and the Mg-additive largely returned to MgO. The LHV of syngas of the MgO-FGT-GS was 9.22 MJ/Nm3, which was 1.3 times higher than raw DSL. Meanwhile, the tar yield decreased by 68.99 %, and the ECC increased by 1.5 times. Therefore, the MgO-FGT-GS process shows a great improvement in gasification and better utilization of CO2. This study provides a technological breakthrough for the full-component utilization and low-carbon conversion of biomass.

Synthesis of renewable C–C cyclic oxygenated compounds dedicated for high-density biofuels from biomass-derived cyclopentanone

Basic magnesium carbonate shows excellent activity for self-condensation of cyclopentanone to yield a biofuel precursor, superior to that of magnesium hydroxide and magnesium carbonate.

Removal of antimony from model solutions, mine effluent, and textile industry wastewater with Mg-rich mineral adsorbents

Naturally occurring layered double hydroxide mineral, brucite (BRU), was compared with hydromagnesite (HYD) and a commercial Mg-rich mineral adsorbent (trade name AQM PalPower M10) to remove antimony (Sb) from synthetic and real wastewaters. The BRU and HYD samples were calcined prior to the experiments. The adsorbents were characterized using X-ray diffraction, X-ray fluorescence, and Fourier transform infrared spectroscopy. Batch adsorption experiments were performed to evaluate the effect of initial pH, Sb concentration, adsorbent dosage, and contact time on Sb removal from synthetic wastewater, mine effluent, and textile industry wastewater. Several isotherm models were applied to describe the experimental results. The Sips model provided the best correlation for the BRU and M10. As for the HYD, three models (Langmuir, Sips, and Redlich–Peterson) fit well to the experimental results. The results showed that the adsorption process in all cases followed the pseudo-second-order kinetics. Overall, the most efficient adsorbent was the BRU, which demonstrated slightly higher experimental maximum adsorption capacity (27.6 mg g-1) than the HYD (27.0 mg g-1) or M10 (21.3 mg g-1) in the batch experiments. Furthermore, the BRU demonstrated also an efficient performance in the continuous removal of Sb from mine effluent in the column mode. Regeneration of adsorbents was found to be more effective under acidic conditions than under alkaline conditions.

Solventing out crystallization-basic magnesium carbonate percipitation for thorough phosphorus removal from ammonium tungstate solution.

The ammonium tungstate solution obtained by leaching scheelite with phosphate contains a large amount of phosphorus. For production of qualified ammonium paratungstate products, phosphorus must be deeply removed from the ammonium tungstate solution. In this study, a novel process for ammonium phosphate recovery and deep phosphorus removal from the solution was proposed. First, ammonium phosphate was crystallized and separated from the ammonium tungstate solution by blowing ammonia and cooling. Results showed that the crystallization ratio of phosphorus was above 95% under the conditions of an ammonia concentration of 4.18 mol/L, an initial phosphorus concentration ranging from 15 g/L to 30 g/L, a holding time of 60 min and the temperature of 20°C. Then, the small portion of phosphorus remaining in the ammonium tungstate solution was further deeply removed by basic magnesium carbonate percipitation. The phosphorus removal efficiency was above 99% and tungsten loss was less than 0.22% under the following conditions: the basic magnesium carbonate stoichiometric ratio was 1.5, the initial phosphorus concentration was ranging from 0.5 to 4 g/L, the reaction time was 120 min and temperature was 25°C. After phosphorus removal, the concentration of phosphorus in the ammonium tungstate solution was below 10 ppm, which meant deep phosphorus removal was achieved.

A green route for the preparation of layered double hydroxides from basic magnesium carbonate

Layered double hydroxides (LDHs) have received extensive attention in many fields such as catalysis, environmental management and medical applications. Typically, expensive soluble metal salts are commonly used as the starting materials for the synthesis of LDHs. Here, we report a novel synthesis route for Mg/Al-LDH by using inexpensive basic magnesium carbonate as the starting material. X-ray diffraction (XRD) and solid-state nuclear magnetic resonance (ssNMR) data show that LDHs with rich defects are formed rapidly at room temperature and good crystallinity can be obtained after further hydrothermal treatment. These results provide a simple, rapid and green preparation method for LDHs.

Li4(OH)3Br/MgO shape stabilized composite as novel high temperature thermal energy storage material

Li4(OH)3Br/Porous-MgO shape stabilized composites were developed in this study as novel high temperature thermal energy storage materials. Li4(OH)3Br, as storage material, owns a large reaction enthalpy (247 J/g) at 288 °C and excellent thermal cycling stability over 600 cycles. Solid MgO nanopowder was selected in a previous study among several metal oxides as the most promising shape stabilizer for Li4(OH)3Br salt satisfying the criteria of wettability, thermochemical compatibility, structural stability and cycling stability. However, this material ensures the structural stability of the composite at a minimum oxide loading of 50 wt%. This relatively high oxide loading will drastically decrease the overall storage capacity of the composite, which is not practical for TES applications. In order to reduce the MgO loading, new mesoporous MgO particles were tested as supporting materials. The idea is to benefit from the mesoporosity in improving the antileakage efficiency of the composite. To do so, three different porous MgO samples were synthesized and tested. Namely, i) Porous MgO (PMgO) synthesized by combustion using Magnesium nitrate, giving a BET surface area of 40 m2/g and a pore volume of 0.217 cm3/g. ii) MgO synthesized by calcination of basic magnesium carbonate (MgO-BMC), giving a high BET surface area of 129 m2/g and a pore volume of 0.294 cm3/g. iii) nanocrystalline MgO (MgO-BM64h) obtained by ball-milling process of commercial MgO micropowder, giving a BET surface area of about 55 m2/g and pore volume of 0.088 cm3/g. The three porous MgO materials exhibit various pore structures. The composites were synthesized following a simple fabrication method by cold compression, mixing and sintering. The results were promising for PMgO based composites where appreciable thermal and structural stability were achieved as 30 wt% oxide loading, whereas MgO-BMC and MgO-BM64h showed poor cycling stability at the same loading. SEM-EDS analyses of PMgO based composite showed an improvement of the homogeneity of the composite structure over 50 melting/solidification cycles. Moreover, the overall thermal conductivity of the composite was enhanced by 33% over pure salt.

Cold sintering of the Mg–C–O–H system

The cold sintering process reproduces the formation of sedimentary rocks in the Earth's crust by molding raw powder and a small amount of solvent at temperatures of about 300 °C or less under uniaxial pressure of several hundred megapascals. Generally, carbonates and hydroxides cannot be hardened by conventional sintering process due to thermal decomposition. In contrast, when this cold sintering process is selected, since the densification of the starting powder can be achieved by a dissolution-precipitation reaction with water as a solvent, carbonates and hydroxides can be hardened at temperatures below their decomposition temperatures. In the Mg–C–O–H system, magnesium hydroxide and a basic magnesium carbonate were selected as starting compounds, and the mechanism of their densification by a cold sintering process was investigated. The average compressive strength of the obtained magnesium hydroxide solidified products after cold sintering at 250 °C and 270 MPa for 60 min, and basic magnesium carbonate solidified products after cold sintering at 150 °C and 270 MPa for 60 min, were 121 MPa (84% relative density) and 275 MPa (88% relative density), respectively. The added water was found to play an important role in promoting a solution-precipitation process inside the magnesium hydroxide or basic magnesium carbonate powder compact, resulting in low-temperature sintering to form hardened bodies in the Mg–C–O–H system.

Influence of Monocalcium Phosphate on the Properties of Bioactive Magnesium Phosphate Bone Cement for Bone Regeneration.

Bone defects occurring for various reasons can lead to deformities and dysfunctions of the human body. Considering the need for clinical applications, it is essential for bone regeneration to exploit a scaffold with bioactive bone cement. In this study, we fabricated bioactive magnesium phosphate bone cement (BMPC) at room temperature; then, it was set at to °C and 100% humidity for 2 h. The process was as follows: Simulating a clinical environment, magnesium oxide (MgO) was formed by calcining basic magnesium carbonate (Mg2(OH)2CO3). MgO, potassium dihydrogen phosphate (KH2PO4) and carboxymethyl chitosan (C20H37N3O14, CMC) were mixed to form magnesium phosphate bone cement (MPC); then, monocalcium phosphate (Ca(H2PO4)2) was added to neutralize the alkaline product after MPC hydration to fabricate bioactive magnesium phosphate bone cement (BMPC). The influence of the doped content of Ca(H2PO4)2 on the properties of bone cement was discussed. The results showed that Ca(H2PO4)2 and CMC can adjust the setting time of bone cement to between 8 and 25 min. The compressive strength increased first and then decreased. After 48 h without additional pressure, the compressive strength reached the maximum value, which was about 38.6 MPa. Ca(H2PO4)2 and CMC can play a synergistic role in regulating the properties of BMPC. The BMPC was degradable in the simulated body fluid (SBF). The results of the cytotoxicity experiment and laser confocal microscopy experiment indicated that BMPC fabricated at room temperature had better biocompatibility and degradability, which was more consistent with clinical operation requirements. BMPC is a promising orthopedic material and is suitable for repairing bone defects.

A simple polyacrylamide gel route for the synthesis of MgAl2O4 nanoparticles with different metal sources as an efficient adsorbent: Neural network algorithm simulation, equilibrium, kinetics and thermodynamic studies

• A polyacrylamide gel method have been used to synthesize the MgAl 2 O 4 nanoparticles. • An artificial neural network model of phase purity of MgAl 2 O 4 was constructed. • The microstructure and adsorption performance of MgAl 2 O 4 nanoparticles were compared. • An adsorption mechanism of MgAl 2 O 4 nanoparticles was proposed. The MgAl 2 O 4 nanoparticles with different particle sizes prepared by a polyacrylamide gel method with different metal salts as raw materials which was used to study its efficiency as an adsorbent for removal of Congo red, acid orange 7 and acid fuchsin from wastewater. It was difficult to obtain pure MgAl 2 O 4 nanoparticles with basic magnesium carbonate or aluminum acetate coupled with other metal salts. Based on the molecular weight, coordination number, ion radius and the number of water of crystallization for the metal salt and the phase purity of the target product, a neural network prediction model was established to predict the effect of synthesis parameters on the phase purity of MgAl 2 O 4 . The microstructure characterization confirmed that the minimum particle size of MgAl 2 O 4 nanoparticles prepared with aluminum nitrate and magnesium sulfate as metal salts was about 22 nm, and the maximum particle size of MgAl 2 O 4 nanoparticles prepared with aluminum nitrate and magnesium chloride as metal salts was about 50 nm. Adsorption experiments of MgAl 2 O 4 nanoparticles were performed as a function of process parameters: various dyes including Congo red, acid orange 7 and acid fuchsin, adsorption time, particles size, initial dye concentration, initial adsorbent concentration, pH value and reaction temperature. The thermodynamic studies showed that the adsorption of MgAl 2 O 4 nanoparticles for removal of Congo red from wastewater is an exothermic and spontaneous process. The maximum adsorption capacity of 89.043 mg/g for the MgAl 2 O 4 nanoparticles was found at 1 g/L of initial adsorbent concentration, 100 mg/L of initial dye concentration, 6.9 of pH, and 299.8 K of temperature for removal of Congo red from wastewater. The adsorption of Congo red, acid orange 7 and acid fuchsin can be assigned to the synergistic effect of electrostatic interaction, pore filling and ion exchange. This present work provides a technical reference for the synthesis of other metal oxide nanoparticles using metal salts with different acid groups.