Production Of Li2CO3 Research Articles

Direct Lithium Extraction from α-Spodumene through Solid-State Reactions for Sustainable Li2CO3 Production.

With increasing battery demand comes a need for diversified Li sources beyond brines. Among all Li-bearing minerals, spodumene is most often used for its high Li content and natural abundance. However, the traditional approach to process spodumene is costly and energy-intensive, requiring the mineral be transformed from its natural α to β phase at >1000 °C. Acid leaching is then applied, followed by neutralization to precipitate Li2CO3. In this work, we report an alternative method to extract Li directly from α-spodumene, which is performed at lower temperatures and avoids the use of acids. It is shown that Li2CO3 is formed with >90% yield at 750 °C by reacting α-spodumene with Na2CO3 and Al2O3. The addition of Al2O3 is critical to reduce the amount of Li2SiO3 that forms when only Na2CO3 is used, instead providing increased thermodynamic driving force to form NaAlSiO4 and Li2CO3 as the sole products. We find that this reaction is most effective at 4 h, after which volatility limits the yield. Following its extraction, Li2CO3 can be isolated by washing the sample using deionized water. This energy-saving and acid-free route to obtain Li2CO3 directly from spodumene can help meet the growing demand for Li.

Energy-economy-environment assessment of key feedstock production for ternary lithium-ion batteries via hydrometallurgical recycling and natural exploitation

The rapid increase in lithium-ion battery (LIB) production has intensified the demand for critical metals such as lithium, cobalt, and nickel, highlighting the urgent need for sustainable practices in LIB lifecycle management. Recycling LIBs is an effective measure generating feedstocks for refabrication in order to address resource strain, mitigate environmental impacts, aligning with the goals of cleaner production and sustainability. This study aims to provide a comprehensive energy-economy-environment assessment framework for feedstock production (Li2CO3, NiSO4·6H2O, CoSO4·7H2O) via hydrometallurgical recycling and natural exploitation. We compare recycling 1t of spent ternary LIBs to traditional natural exploitation methods by considering energy consumption, economic costs, and environmental impacts. Recycling routes incur 2.9–9.3 × 104 MJ energy consumptions, 3.8–4.4 × 104 CNY economic costs and 1.5–4.2 × 103 kg CO2 eq. emissions, while natural exploitation routes result in 4.6–8.6 × 104 MJ, 1.1–2.0 × 104 CNY and 2.7–3.9 × 103 kg CO2 eq, respectively. This study reveals that, in most environmental impact categories, natural exploitation routes fall between pyrolysis and non-pyrolysis recycling routes. Furthermore, significant difference in environmental and energy impacts per unit feedstock production are observed when utilizing mass-based and value-based allocation methods. When adopting mass-based, carbon emissions of Recycling route1 (based on full-component pyrolysis) is 41% of that using Li2CO3 from brine route for 1 kg of Li2CO3 production. This value increases to 112% when adopting value-based. Similarly, energy consumptions of Recycling route 1 are 65% and 175% of those using Li2CO3 from brine route, for mass-based and value-based methods, respectively. Our findings provide insights supporting sustainable battery recycling processes, which could further contribute to the broader field of cleaner production by promoting resource efficiency, reducing environmental impacts, and fostering sustainable industrial practices.

CO2 microbubbling system for lithium carbonate precipitation

Lithium carbonate (Li2CO3) is becoming increasingly valuable with the growth of the lithium-ion battery industry. For effective Li2CO3 production, the efficient supply of the carbonate source to the solution is crucial. Conventionally, sodium carbonate has been used as the carbonate source; however, the importance of CO2 utilization has been recently recognized. Conventional CO2-based carbonate sourcing exhibits limited efficiency. In this study, we propose a CO2 microbubbling system based on a rotating nozzle for Li2CO3 precipitation. The CO2 micro-bubbling system demonstrated a 1.6 to 1.9 times greater precipitation reaction rate than that of the conventional CO2 bubbling system. This rate enhancement could be attributed to the increased gas-liquid contact surface and greater residence time due to the generation of CO2 microbubbles. Additionally, the Li2CO3 reaction terminated when the pH of the solution dropped below 9.4–9.7 approximately. The re-dissolution of precipitated Li2CO3 occurred below this pH range as bicarbonate ions became the dominant species over carbonate ions. This study successfully demonstrated that CO2 microbubbling technology could be an excellent alternative for carbonate sourcing systems in the Li2CO3 production industry.

Lithium Pollution and Its Associated Health Risks in the Largest Lithium Extraction Industrial Area in China.

Lithium (Li) is an important resource that drives sustainable mobility and renewable energy. Its demand is projected to continue to increase in the coming decades. However, the risk of Li pollution has also emerged as a global concern. Here, we investigated the pollution characteristics, sources, exposure levels, and associated health risks of Li in the Jinjiang River basin, the largest area for Li2CO3 production in China. Our results revealed the dominant role of Li extraction activities in the pollution of the river, with over 95% of dissolved Li in downstream river water being emitted from this source. Moreover, the Li concentration in aquatic plants (i.e., water hyacinth) and animals (i.e., fish) significantly increased from upstream to downstream areas, indicating a significant risk to local aquatic ecosystems. More importantly, our study found that local residents were suffering potential chronic noncarcinogenic health risks primarily from consuming contaminated water and vegetables. We also investigated the pollution characteristics of associated elements present in Li ores (e.g., Rb, Cs, Ni, and F-). By uncovering the remarkable impact of Li extraction activities on the Li content in ecosystems for the first time, our study emphasizes the importance of evaluating Li pollution from Li-related industrial activities, including mining, extraction, and recovery.

An efficient approach for preparation of battery-grade Li2CO3 from intermediate product Li2SiO3

The continuous development of lithium-ion batteries (LIBs) manufacturing industry calls for the mass production of Li2CO3, which serves as a pivotal raw material for LIBs. In our previous study, Li was successfully precipitated as intermediate product Li2SiO3 from an alkaline solution containing Si by the hydrothermal precipitation method, realizing the preliminary separation of Li and impurities. In this research, H2SO4 digestion-water leaching-Na2CO3 precipitation process was proposed to manufacture Li2CO3 from the intermediate product Li2SiO3. Firstly, the reaction feasibility of H2SO4 digestion-water leaching and direct H2SO4 leaching for Li2SiO3 were comparatively evaluated through thermodynamic calculation and experimental research. Compared to direct H2SO4 leaching, H2SO4 digestion-water leaching process is preferred in view of its excellent filtration properties. Subsequently, systematic digestion and leaching experiments showed that up to 97.1 % of Li was extracted under the optimized conditions, and the concentration of Li in the leach liquor is as high as 29.33 g/L. After pH adjustment and Al removal, Na2CO3 precipitation were adopted for Li2CO3 production. The equilibrium relationship in Li2SO4-Na2CO3-H2O system was analyzed to predict the precipitation behavior of Li and select appropriate operation window for Li2CO3 preparation. Finally, with an additional carbonation-decomposition process, a Li2CO3 product with a purity of 99.51 % is produced. This process realizes efficient synthesis of battery-grade Li2CO3 from the intermediate product Li2SiO3.

Carbon and water footprint of battery-grade lithium from brine and spodumene: A simulation-based LCA

Increasing demand for lithium driven by e-mobility spurs the expansion of lithium projects and exploration of lower-grade resources. This article combines process simulation (HSC Chemistry) and life cycle assessment tools to develop life cycle inventories considering declining ore grades scenarios for battery-grade Li2CO3 production from pivotal sources and regions (Salar de Atacama - brine and Greenbushes - spodumene). Depending on the ore grades, climate change results range from 5,0 to 25,0 kgCO2eq/kg Li2CO3 for brine and from 17,1 to 22,3 kgCO2eq/kg Li2CO3 for spodumene. Water consumption for brine varies from 0,2 to 7,7 m3/kg Li2CO3, depending on flow accounting, while for spodumene, it ranges from 0,2 to 0,5 m3/kg Li2CO3. The research shows that decreasing ore grade can lead to a fivefold increase in the carbon footprint for brine-based production and a 1.3-fold increase for spodumene. This underscores the importance of decarbonizing energy provision for lithium production to guarantee a sustainable battery supply chain. This research offers insights into using process simulation to enhance existing LCA studies in the raw materials industry and further develop inventory datasets, considering variations such as deposit ore grades.

Exploring the synergistic effects of chemical activation and N-doping in carbon nanospheres for advanced Li–CO2Mars batteries

Lithium-CO2 batteries can be used to mitigate CO2 emissions by recycling CO2 for energy storage and potential utilization as a standalone energy storage device on Mars as it contains 95 % CO2 (Li–CO2Mars batteries). The incomplete decomposition of the discharge product, Li2CO3, reduces the battery's cycle life, limiting its practicability. Herein, we develop a hierarchical porous, high surface area (1845 m2 g−1) activated N-doped candle soot (ANCS) carbon catalyst by modifying the candle soot carbon through the combination of the techniques of activation and hereroatom N-doping for enhanced CO2 reduction and evolution reactions. The ANCS-based Li–CO2Mars batteries exhibit a high discharge capacity of 11,490 mAh g−1 and a stable cycle life of over 130 cycles with a low overpotential of 1.4 V at the high current density of 200 mA g−1. Furthermore, density functional theory (DFT) studies reveal that the ANCS catalyst's higher affinity for CO2 adsorption and Li2CO3 production leads to the excellent performance of the Li–CO2Mars batteries. The developed method offers way of repurposing the pollutant carbons as metal-free carbon catalysts for the future progress of the Li–CO2Mars batteries for use as a future sustainable energy source for both Earth and Mars.

Application of vacuum membrane distillation process for lithium recovery in spent lithium ion batteries (LIBs) recycling process

The feasibility of using vacuum membrane distillation (VMD) for lithium recovery by concentrating the discharged leachate from spent lithium ion batteries (LIBs) recycling process was evaluated. The performance of VMD was compared with that of direct contact membrane distillation (DCMD) in terms of water flux, concentration rate, membrane wetting, and economic feasibility. VMD achieved a higher volume concentration factor (VCF) of 45 compared to the VCF of 25 achieved by DCMD in the LiCl feed solution. In the Li2SO4 feed solution, VMD and DCMD were concentrated to VCF15 and VCF 17, respectively, before wetting occurred. The stability of the MD process was verified using feed solutions containing nickel and manganese, which are cathode materials that can cause scaling even at low concentrations. Low concentrations of nickel and manganese did not significantly affect the maximum VCF or wetting; however, high concentrations of nickel and manganese affected the stability of the MD process. VMD exhibited a higher flux and 32 % lower thermal energy consumption than DCMD. Furthermore, the expected cost of Li2CO3 production with VMD for leachate concentration was $8.31–10.65/kg. The VMD concentration process is a feasible option for recovering lithium from the discharged leachate from spent LIBs recycling process.

Recovery of Li2SO4 from lithium-precipitated mother liquor via a Pb/FePO4 membrane-free electrochemical system

Ore is the primary source of Li2CO3 production, but approximately 10–15% of lithium remains in the lithium-precipitated mother liquor for each ton of Li2CO3 produced. Therefore, efficient recovery of Li2SO4 from this solution is essential to ensure Li2CO3 supply. The conventional “(+) LiFePO4/FePO4 (−)” membrane system has been successfully used to extract LiCl from brine. However, the large radius of SO42− in the mother liquor significantly increases the cell voltage of this system, which is not favorable for separating Li+ and Na+. We therefore developed a novel “(+) Pb/FePO4 (−)” membrane-free Li2SO4 extraction system that uses Pb and FePO4 to capture SO42− and Li+, which was then released by switching the electrode polarity after the adsorption was completed. The Li+ concentration in the mother liquor decreased from 1.3 to 0.014 g·L−1 in two cycles, and the Li+ recovery rate was 98.9%. The Li+ concentration in the recovery liquor reached 1.356 g·L−1, with a Li–Na separation coefficient of 304. In addition, the new system did not suffer from lead dissolution loss, and the adsorption capacity of Li+ was 95.44% of the initial capacity after 15 cycles. Overall, this membrane-free lithium extraction system can provide a direction for extracting Li2SO4 from sulfate systems.

Preparation of Battery Grade Li2CO3 from Defective Product by the Carbonation‐Decomposition Method

AbstractBattery grade Li2CO3 is successfully synthesized by the carbonation‐decomposition method using defective crude Li2CO3 with the purity of 98.56 wt% containing 5873 ppm SO42− and other impurities such as Na, K, Ca, Fe, and Mg. Filter operation is found to be very important to improve quality of products. The purified Li2CO3 precipitation acquired by filtering the LiHCO3 solution possesses a higher purity of 99.65 wt% and greater whiteness with lower amounts of SO42− (222.0 ppm) and Fe (6.6 ppm). For further purification, ethylenediaminetetraacetic acid disodium salt is added into the LiHCO3 solution then Ca and Fe contents in purified Li2CO3 are reduced to 2.9 and 0.7 ppm, respectively. The removal efficiencies obtained for Ca, Fe, and SO42− are of 80.05%, 99.4%, and 97.5%, respectively. The research of reaction kinetics shows that the rate‐determining step of the carbonation process is diffusion control and the generated HCO3− ions can resist the further dissolution of CO2. The theoretical thermal decomposition temperature is 277.10 K by the thermodynamic calculation. SO42− impurity comes from absorbed Na2SO4 and doped Li2SO4. This work is of great significance to economically and simply treat defective product with high impurity content in the actual Li2CO3 production process.

Preparation of lithium carbonate from waste lithium solution through precipitation and wet conversion methods

The recovery of lithium compounds from various Li resources is attracting attention due to the increased demand in the Li-ion battery (LIB) industry. This study aimed to secure lithium carbonate (Li2CO3) using the waste Li solution generated from the cathode manufacturing process. The effects of initial Li+ concentration, solution pH, and applied phosphate compounds were examined on converting Li-ion into lithium phosphate (Li3PO4) by a precipitation method. Li2CO3 was then obtained from Li3PO4 by reflux and subsequent carbonation methods, in which a concentrated Li solution was produced from Li3PO4 by reaction with metal chloride solutions. Among the tested metal chlorides (AlCl3, MgCl2, and CaCl2), CaCl2 showed the best performance to produce a concentrated Li solution. The highest conversion efficiency (97%) from Li3PO4 to Li solution was observed at 80 °C, and the highest Li concentration (55,900 mg/L) was obtained at a solid(g)/liquid(L) ratio of 500 by reflux reaction. High purity Li2CO3 was produced from the obtained Li solution by purification using sodium hydroxide, and its carbonation using sodium carbonate in turn. The proposed method shows an alternative way to secure Li2CO3 from waste Li solution, in which no acid leaching of Li3PO4 is required to prepare concentrated Li solution to be used Li2CO3 production.

Selective recovery and efficient separation of lithium, rubidium, and cesium from lepidolite ores

Sulfation and decomposition were proposed to selectively recover lithium, rubidium, and cesium from lepidolite ore. The purpose was to solve the problems of high acid consumption and the difficulty of separating lithium and aluminum in the sulfuric acid method. First, the theoretical feasibility of the process was verified by thermodynamic calculations. The optimal parameters were determined according to the theoretical and experimental results. The extraction rates of lithium, rubidium, and cesium were 90.5%, 91.2%, and 89.4%, respectively, whereas those of aluminum and iron were only 0.08% and 0.02%, respectively. The selective extraction of lithium, rubidium, and cesium was realized, and 90.4% of sulfuric acid could be recycled during the process. Subsequently, the mechanism was discussed by XRD and SEM-EDS analysis. The first-step roasting was the sulfation process of lepidolite, and the second-step roasting was the decomposition process of partial sulfates. The separation of alkali elements and impurity elements could be realized by simple deionized water leaching. The production of Li2CO3 and single-alkali sulfates (K2SO4, Rb2SO4, and Cs2SO4) were obtained through the efficient separation methods of carbonization precipitation and solvent extraction. This process achieved the selective recovery and efficient separation of lithium, rubidium, and cesium from lepidolite ores. At the same time, the recycling of sulfuric acid was realized; it greatly reduced the amount of reagents, such as acid and alkali. It is an efficient, clean, and sustainable process for the utilization of lepidolite ores.

Energy, greenhouse gas, and water life cycle analysis of lithium carbonate and lithium hydroxide monohydrate from brine and ore resources and their use in lithium ion battery cathodes and lithium ion batteries

Life cycle analyses (LCAs) were conducted for battery-grade lithium carbonate (Li2CO3) and lithium hydroxide monohydrate (LiOH•H2O) produced from Chilean brines (Salar de Atacama) and Australian spodumene ores. The LCA was also extended beyond the production of Li2CO3 and LiOH•H2O to include battery cathode materials as well as full automotive traction batteries to observe the effect that the lithium production pathways had on these end products. The LCA here covers material, water, and energy flows associated with lithium acquisition; lithium concentration; production of lithium chemicals, battery cathode powders, and batteries; and associated transportation activities along the supply chain. Based on battery cathode material, the difference in lithium source represents a difference of up to 20% for NMC811 cathode greenhouse gases (GHGs) and up to 45% for NMC622 cathode GHGs. For full batteries, this represents a difference of up to 9% for NMC811 batteries and 20% for NMC622 batteries. Production of Li2CO3 from brine-based resources had less life cycle GHG emissions and freshwater consumption per tonne of Li2CO3 than Li2CO3 from ore-based resources. And LiOH•H2O produced from brine-based lithium also had less life cycle GHG emissions and freshwater consumption per tonne of LiOH•H2O than LiOH•H2O from ore-based resources.

A Comprehensive Membrane Process for Preparing Lithium Carbonate from High Mg/Li Brine.

The preparation of Li2CO3 from brine with a high mass ratio of Mg/Li is a worldwide technology problem. Membrane separation is considered as a green and efficient method. In this paper, a comprehensive Li2CO3 preparation process, which involves electrochemical intercalation-deintercalation, nanofiltration, reverse osmosis, evaporation, and precipitation, was constructed. Concretely, the electrochemical intercalation-deintercalation method shows excellent separation performance of lithium and magnesium, and the mass ratio of Mg/Li decreased from the initial 58.5 in the brine to 0.93 in the obtained lithium-containing anolyte. Subsequently, the purification and concentration are performed based on nanofiltration and reverse osmosis technologies, which remove mass magnesium and enrich lithium, respectively. After further evaporation and purification, industrial-grade Li2CO3 can be prepared directly. The direct recovery of lithium from the high Mg/Li brine to the production of Li2CO3 can reach 68.7%, considering that most of the solutions are cycled in the system, the total recovery of lithium will be greater than 85%. In general, this new integrated lithium extraction system provides a new perspective for preparing lithium carbonate from high Mg/Li brine.

Extraction Mechanism of Lithium from the Alkali Solution with Diketonate-Based Ionic Liquid Extractants

Four diketonate-based functional ionic liquids (ILs) with trialkylmethylammonium ([A336]+) cation were synthesized, and the synergistic extraction systems containing IL and thetrialkylphosphineoxid...

Mechanism and Modelling of Reactive Crystallization Process of Lithium Carbonate

The reactive crystallization of lithium carbonate (Li2CO3) from lithium sulfate (Li2SO4) and sodium carbonate (Na2CO3) solutions is a key process in harvesting solid lithium, whether from ores, brines, or clays. However, the process kinetics and mechanism remain poorly understood and the modelling of the reactive crystallization of Li2CO3 is not available. Hence, this work aims to determine the kinetics and mechanisms of the nucleation and growth of Li2CO3 reactive crystallization by induction time measurements and to model and optimize the crystallization process using response surface methodology. Induction time measurements were carried out as functions of initial supersaturation and temperature using a laser method. It was found that the primary nucleation mechanism of Li2CO3 varies with solution supersaturations, in which, expectedly, the heterogenous nucleation mechanism dominates at low supersaturations while the homogeneous nucleation mode governs at high supersaturations. The transition point between heterogenous and homogenous nucleation was found to vary with temperatures. Growth modes of Li2CO3 crystals were investigated by relating induction time data with various growth mechanisms, revealing a two-dimensional nucleation-mediated growth mechanism. The modelling and optimization of a complex reactive crystallization were performed by response surface methodology (RSM), and the effects of various crystallization parameters on product and process performances were examined. Solution concentration was found to be the critical factor determining the yield of crystallization, while stirring speed was found to play a dominant role in the particle size of Li2CO3 crystals. Our findings may provide a better understanding of the reactive crystallization process of Li2CO3 and are critical in relation to the crystallization design and control of Li2CO3 production from lithium sulfate sources.

Magnesium Oxychloride Cement Prepared by the Byproduct of Li2CO3 from Salt Lake and Hydrochloric Acid

In this study, Magnesium Oxychloride Cement (MOC) was prepared from magnesium slag, a byproduct of the production of Li2CO3 from salt lakes, and hydrochloric acid. First, the composition and activity of magnesium slag calcined at various temperatures were investigated by XRD and hydration method. Then MOC specimens were prepared with calcined magnesium slag and various concentration of hydrochloric acid. The setting time of MOC paste was measured as well as the compressive strength was conducted at 3d, 7d and 28d. The hydration products and microstructure of the specimens were analyzed by XRD and SEM, respectively. The results demonstrated that the activity of magnesium slag decreased with increasing calcination temperature. The setting time and compressive strength of MOC specimens raise first down second with increasing the concentration of hydrochloric acid. However, MOC with a high concentration of hydrochloric acid could have a high early strength. The MOC specimens prepared by magnesium slag calcined at 500 ℃ and hydrochloric acid of 6 mol·L–1 exhibited a compressive strength of 77.9 MPa and 112.8 MPa at 3d and 28d respectively

Development of a thermodynamic model for the Li2CO3-NaCl-Na2SO4-H2O system and its application

Abstract The study of the solid-liquid phase equilibrium for the Li2CO3-NaCl-Na2SO4-H2O system is of significance to separate lithium from the mother liquor obtained by the reaction of lithium chloride/lithium sulfate and sodium carbonate. The phase equilibrium data for the binary system of Li2CO3-H2O, the ternary systems of Li2CO3-NaCl-H2O and Li2CO3-Na2SO4-H2O, and the quaternary system of Li2CO3-NaCl-Na2SO4-H2O over the temperature range from 283.15 K to 363.15 K were measured. Based on the Pitzer’s model embedded in the Aspen Plus™, the phase equilibrium data for the systems of NaCl-H2O, Na2SO4-H2O and NaCl-Na2SO4-H2O taken from literatures were firstly predicted to verify the applicability of parameters from the default database and literatures. Subsequently, besides the solubility of Li2CO3 in water at different temperatures, the values for the systems of Li2CO3-NaCl-H2O and Li2CO3-Na2SO4-H2O at 298.15 K and 343.15 K were correlated, and then the obtained parameters can well predict the phase equilibrium data for the systems of Li2CO3-NaCl-H2O, Li2CO3-Na2SO4-H2O Li2CO3-NaCl-Na2SO4-H2O at T = (313.15, 323.15 or 363.15) K. Through the rigorous thermodynamic model representing the Li2CO3-NaCl-Na2SO4-H2O system developed, the phase diagram of the ternary Li2CO3-NaCl-H2O system at T = (298.15, 343.15 or 363.15) K visualized with lucidity, and the course of crystallization to produce Li2CO3 from the mother liquor was illustrated. All of these will provide a thermodynamic basis for the separation of lithium from mother liquor and optimization of Li2CO3 production process.

The effect of slag on the properties of magnesium potassium phosphate cement

Magnesium potassium phosphate cement (MKPC) incorporated with slag was prepared from the byproduct boron-containing magnesium oxide (B-MgO) from the production of Li2CO3 from salt lakes. The influence of the slag content on the setting time, compressive strength, water resistance and seawater corrosion resistance of MKPC was investigated. The composition and microstructure of MKPC were also studied in detail. The results demonstrate that the setting time of MKPC increases with increasing slag content. The compressive strength at 3h and 28d of MKPC specimens with 20wt% slag can reach approximately 35MPa and 60MPa, respectively. Moreover, slag significantly improves the water resistance and the seawater corrosion resistance of MKPC. The properties of MKPC incorporated with 20wt% slag indicated that it met the requirements for rapid repairing materials.

Magnesium potassium phosphate cement prepared by the byproduct of magnesium oxide after producing Li2CO3 from salt lakes

Developing new types of chemically bonded phosphate ceramic materials that are environment-friendly, inexpensive and energy-efficient, has become a central theme today. Therefore, in this study, magnesium potassium phosphate cement (MKPC) was prepared from boron-containing magnesium oxide (B-MgO), a byproduct of the production of Li2CO3 from salt lakes. The properties of B-MgO calcined at various temperatures were investigated by XRD, SEM, LSPA and SNAA. The MKPC specimens were prepared at various calcination temperatures (from 800°C to 1400°C) of B-MgO and with various molar ratios of B-MgO to KH2PO4 or KDP (M/P) ranging from 3 to 6. Compression tests were conducted at various curing ages from 3h to 28d. The hydration products and microstructure of the specimens were analyzed by XRD and SEM, respectively. The experimental results demonstrated that the properties of B-MgO, such as the specific surface area, the deformation ratio and the total pore volume decreased with increasing calcination temperature. In addition, the early compressive strength of MKPC specimens decreased with increasing calcination temperature of B-MgO, and the long-term compressive strengths of MPC mortar remained constant with increasing calcination temperature of B-MgO. These results also indicated that cement with a high M/P ratio could have a high early strength. The MKPC specimens prepared by B-MgO calcined at 1000°C and a M/P ratio of 6 exhibited a compressive strength of 35.6MPa at 3h, which met the mechanical property requirement of quick-repair materials.