Table of Content

28 October 2024, Volume 24 Issue 10

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Contents

Cover and Contents

The Chinese Journal of Process Engineering. 2024, 24(10):  0. 

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Review

Research progress on dissolution behavior of drugs based on the drug-excipient interaction

Kunwang SONG Yewei DING Chen SHEN Haomin WU Yuanhui JI

The Chinese Journal of Process Engineering. 2024, 24(10):  1127-1136.  DOI: 10.12034/j.issn.1009-606X.224021

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Pharmaceutical excipients, also known as "inactive ingredients", are other components in pharmaceutical preparations besides active ingredients. Pharmaceutical excipients are an indispensable and important component in pharmaceutical preparations, and they can significantly affect the release performance of pharmaceutical preparations by forming drug excipient interactions, which is crucial for the effectiveness and safety of pharmaceutical preparations. The development of high-end preparations also puts higher requirements on excipients. Therefore, it is necessary to analyze the mechanism by which excipients in high-end formulations affect the quality of drug formulations. Although the addition of excipients can enhance the release and bioavailability of active ingredients in drugs, improve and maintain drug stability, achieve controllable targeted release of drugs, and act as masking and sweeteners to improve drug bioavailability and patient adherence, more and more studies have shown that excipients can produce physiological activity and affect drug pharmacokinetics, causing adverse reactions such as allergies or intolerance. Large amounts of ingested excipients may also inhibit drug release by interacting with drugs. This review briefly describes the impact mechanisms of commonly used excipients on drug release from the perspective of drug excipient interactions, such as polymers and mesoporous silica. At the same time, it summarizes the research progress of excipient controlled drug release mechanisms based on mathematical models, molecular simulations, and machine learning methods based on drug excipient interactions, and proposes the development direction of future pharmaceutical excipient database establishment for high-throughput screening of suitable pharmaceutical excipients. Determine the optimal drug loading and excipient addition, and provide data support and theoretical guidance for selecting appropriate production processes.

Recent advances of kinetic promoters for the formation of light hydrocarbons and carbon dioxide hydrates

Xiaomei YANG Peng XIAO Changyu SUN Guangjin CHEN

The Chinese Journal of Process Engineering. 2024, 24(10):  1137-1148.  DOI: 10.12034/j.issn.1009-606X.223332

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Hydrate-based carbon sequestration in deep ocean is a highly promising way for carbon sequestration. The formation of carbon dioxide hydrate is the basis of hydrate-based carbon sequestration. However, the formation rate of gas hydrate is very slow without human intervention. Among the methods that intensify gas hydrate formation, the use of kinetic promoters has been proven to be the most effective one. Though the kinetic promoters have been extensively and deeply studied, they are mainly used for intensifying the formation of light hydrocarbons hydrates, which is the basis of hydrate-based industrial technologies, such as hydrate-based gas storage and gas separation. However, the kinetic promoters that is suitable for the formation of light hydrocarbons hydrates are not necessarily suitable for the formation of carbon dioxide hydrate. Therefore, in order to find out the most effective kinetic promoters to intensify the formation of carbon dioxide hydrate, it is necessary to distinguish the kinetic promoters of carbon dioxide hydrate from that of light hydrocarbon hydrates. Aiming at the intensification of the formation of carbon dioxide gas hydrate, the evolution and the current research status of kinetic promoters are reviewed. The effects of different kinetic promoters on the formation of the same gas hydrate, and the effects of the same kinetic promoter on the formation of above two kinds of gas hydrates are compared. The different effects of kinetic promoters on promoting light hydrocarbons hydrates and carbon dioxide hydrate are revealed. Based on the research status of the kinetic promoters, the study of the intensification mechanisms of the kinetic promoters on different gas hydrates, the establishment of the criteria for assessing the kinetic promoters, the enhancement of the removal of the formation heat of gas hydrates, and the further improvement on intensifying gas hydrate formation are proposed, to provide new methods for the practical application of hydrate-based carbon sequestration.

Research Paper

Experimental analysis of enhanced absorption of CO₂ by NaOH solution in Kenics static mixer

Yanfang YU Henglei YU Huibo MENG Puyu ZHANG

The Chinese Journal of Process Engineering. 2024, 24(10):  1149-1157.  DOI: 10.12034/j.issn.1009-606X.224110

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The carbon peaking and carbon neutrality goals has been concerned, and the current global warming problem caused by excessive carbon dioxide emissions is very serious. In order to alleviate global ecological problems and better achieve the dual-carbon strategy, the research and development of carbon dioxide capture technology is indispensable. In order to enrich the application of static mixers in the field of carbon dioxide absorption, Kenics static mixer (KSM) was used as the enhanced reaction equipment. Based on sodium hydroxide aqueous solution and carbon dioxide (NaOH-CO2) system, the absorption efficiency of carbon dioxide concentration in the range of 25%~33% volume concentration was analyzed using KSM and empty tube structures under different sampling positions and gas-liquid flow rates. The absorption efficiency of carbon dioxide was measured by automatic potentiometric titration. The absorption performance of the KSM structure was compared with that of the empty pipe. The results showed that the maximum absorption efficiency of CO2 in KSM was 72.3% higher than that of the empty pipe. The absorption efficiency of CO2 decreased with the increase of the liquid phase flow rate (QL) at a certain gas phase flow rate (QG) in the empty pipe structure. In contrast, the absorption efficiency of CO2 increased with the increase of QL when KSM elements were installed in the pipe. The volume energy dissipation rate (ε) of KSM structure was analyzed, and it was concluded that the minimum ε was 4.85 m2/s3 when the CO2 absorption efficiency reached more than 90%. The ε increased by 14.7% when total gas-liquid flow rate (QT) varied from 20 L/min to 22 L/min at QG=6 L/min from the first sampling point (Z1) to second sampling point (Z2) in the pipeline. However, the ε increased by 7.83% when QT changed in the same range at QL=14 L/min. The results showed that the change of ε was more affected by QL than QG, and the system energy consumption and reaction were more obvious from Z1 to Z2 in the pipeline. When the gas superficial velocity (UG) was constant, the Darcy friction coefficient (f) decreased with the increase of the liquid superficial velocity (UL), and when the UL was constant, the f decreased with the increase of the UG. The empirical correlation among the UG, UL, and f was obtained by fitting the experimental data with R2=0.999, the correlation deviation ranged from -0.88% to 0.82%.

Influence of interfacial height on separation effect of gravity oil-water separators

Aobang DING Zongyong WANG Zhanhua XU Ding WANG Lixun MA Ming SUN

The Chinese Journal of Process Engineering. 2024, 24(10):  1158-1165.  DOI: 10.12034/j.issn.1009-606X.224011

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The height of the separation interface in the gravity oil-water separator determines the volume ratio of the oil and water phases, which affects the height of the oil and water phases floating up or settling down in the separator, and has a direct impact on the separation effect. In order to investigate the influence of the height of separation interface on the separation effect of the gravity oil-water separator, numerical simulation is carried out using Fluent software to investigate the separation effect under different inlet flow rates and different water phase outlet flow ratios. The results show that the height of separation interface decreases with the increase of water phase export flow rate, and the lower the oil content in the inlet, the faster the height of separation interface decreases. As the height of separation interface decreases the oil content in the oil phase export gradually increases, and the separation effect is the best when the separation interface is in the vicinity of the axis of the separator, and the oil content of oil phase export can be up to 97%~98% under different inlet flow rates. As the height of separation interface decreases, the high-speed region behind the rectifier plate of the separator gradually moves down and the velocity gradient gradually decreases, which improves the velocity uniformity within the polystructure and reduces the influence of the radial velocity on the oil phase export, and thus improves the separation effect.

Surface modification and catalytic performance study of Cu-based carbon dioxide to methanol hydrogenation catalyst

Qiang YANG Gang WANG Chunshan LI

The Chinese Journal of Process Engineering. 2024, 24(10):  1166-1176.  DOI: 10.12034/j.issn.1009-606X.224059

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Development of effective copper-based catalyst for CO2 hydrogenation to methanol is of great significance, considering the utilization of this greenhouse gas. In this work, a series of surface promoter-modified (Mn, In, Mo, Mg, Zr) catalyst were synthesized by coprecipitation-post impregnation method and evaluated for CO2 hydrogenation to methanol in fixed-bed reactor. The role of metal modifier on the physicochemical properties of Cu/ZnO/Al2O3 (CZA) were investigated through CO2-TPD, XRD, XPS and H2-TPR. In addition, the catalytic mechanism for CO2-to-methanol hydrogenation was revealed by employing in situ IR. The results showed that the Mn-modified CZA with good reduction behavior, excellent CO2 adsorption capacity and suitable Cu+/Cu0 ratio exhibited the best performance. The metal element loaded on catalyst strengthened the interactions between the copper and support, suppressing the growth of Cu. The appropriate Cu+/Cu0 ratio facilitates the stabilization and conversion of methoxy, resulting in increased methanol production. Compared to the untreated CZA catalyst, the Mn-modified catalyst has more medium strong base sites on the surface, which helps to adsorb more CO2 for further hydrogenation to form formate, methoxyl and other intermediates. The incorporation of metal component in CZA facilitated the catalyst reduction ability. The catalytic mechanism follows the formate pathway and the methoxyl species is the crucial intermediate. The Cu nanoparticles on the catalyst surface showed an increased capacity for H2 dissociation when using Mn-modified CZA catalysts. This is due to stronger metal-carrier interactions. The presence of interstitial H in the carriers contributed to the generation of formate species. The dissociated H atoms from the surface Cu nanoparticles replenished the consumed interstitial H. The modified catalyst's interstitial H presence and enhanced H2 dissociation ability accelerated the formation and conversion of intermediate species, promoting methanol generation.

Effect of burning drops of electrical wires at different heights on the ignition and combustion of typical insulation materials

Peng XU Xinjie HUANG Meng ZHANG Hailong DING Shuaishuai WANG Pengyuan ZHANG Gang TANG

The Chinese Journal of Process Engineering. 2024, 24(10):  1177-1185.  DOI: 10.12034/j.issn.1009-606X.224005

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Foam is widely used because of its good properties, but it is flammable and poses a major safety hazard. In this work, the effects of liquid droplets produced by electrical wires at different heights (10, 20, 30, 40, and 50 cm) on the ignition of three types of foam insulation materials (EPS, RPUF, RPUF+EG10) were investigated by means of experimental methods, including droplet fall, flame height, flame temperature, and heat changes. The results show that the droplet process of droplets at different heights exhibits different drip phenomena, there is a "flame up" and "flame out" phenomenon. The penetration or combustion behavior of the three foams are positively correlated with the number and height of droplets dropped, EPS foam will be penetrated by high temperature droplets, while RPUF and RPUF+EG10 foam will be ignited by high temperature droplets, and the burning intensity of RPUF foam is much greater than that of RPUF+EG10 foam. The flame height of the wire insulation was inversely affected by the flame height of the RPUF foam surface, with the wire insulation extinguishing at heights of 10, 40, and 50 cm. Also, at the end of the RPUF foam combustion, the droplet flame remained adhered to the carbon layer, producing two temperature peaks during the combustion of the RPUF foam. On the other hand, the RPUF+EG foam formed a small pool fire with temperature stabilisation. In the combustion process, RPUF foam has a heat received increasing zone and a heat stabilisation zone, and the heat emitted from the combustion of the RPUF+EG10 foam will keep increasing with the formation of small pool fires on the foam.

Research on the preparation of high tap density trimanganese tetraoxide by precipitation-roasting method

Yongbin YANG Xiaoxuan ZHANG Lang LIAO Yinrui DONG Qian LI Yan ZHANG Tao JIANG

The Chinese Journal of Process Engineering. 2024, 24(10):  1186-1195.  DOI: 10.12034/j.issn.1009-606X.224083

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Transition metal oxide trimanganese tetraoxide has been widely utilized in the field of energy storage, particularly in the battery industry, due to its distinctive structural characteristics and physicochemical properties. In recent years, the battery industry has placed higher demands on the product quality of trimanganese tetraoxide, with product tap density being one of the key factors affecting battery material performance. Its magnitude directly impacts the energy density, power density, and safety performance of the battery, while better tap density also contributes to enhancing the battery's cycle stability. During the study, it was found that the roasting system had a significant influence on the tap density of the roasted products. Therefore, to enhance the tap density of trimanganese tetraoxide, this study employed high-purity manganese sulfate as the raw material and ammonia as the precipitating agent to prepare trimanganese tetraoxide with high tap density through the precipitation-roasting method of manganese sulfate solution. The effects of precipitation reaction parameters and thermal system on the tap density of trimanganese tetraoxide were explored, and the morphology, structure, and composition of manganese trioxide products were characterized. The experimental results indicated that under the optimal process conditions, with an ammonia-to-manganese ratio of 3:1, a manganese sulfate concentration of 2.0 mol/L, a roasting temperature of 1150℃, a roasting time of 4 hours, and a forced ventilation roasting atmosphere, the best outcomes were achieved. Under these conditions, the manganese content of trimanganese tetraoxide was 71.91wt%, with a D50 of 10.723 μm and a specific surface area of 1.786 m2/g, exhibiting a spherical morphology. The content of trace elements met the requirements, and the tap density was 2.85 g/cm3, meeting the industry standard for high-purity trimanganese tetraoxide.

Research on composition customization strategy and magnetic properties optimization of soft magnetic composite cores based on interfacial solid reaction

Rui WANG Hui KONG Haichuan WANG Lejun ZHOU Xi'an FAN Zhaoyang WU

The Chinese Journal of Process Engineering. 2024, 24(10):  1196-1207.  DOI: 10.12034/j.issn.1009-606X.223366

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Soft magnetic composite cores (SMCs) are considered the most promising electromagnetic conversion device due to their excellent properties, including high saturation magnetisation, high permeability, and relatively low core loss. However, core loss and permeability, as the key performance parameters for the effective operation of electromagnetic devices, are often restricted. Therefore, by adjusting the distribution characteristics of the powder matrix, the insulating layer, and increasing the ferromagnetic filling factor within the soft magnetic composite core, in-situ coating of the insulating layer can be realised, which helps to simultaneously reduce core loss and improve magnetic permeability. In this work, a novel interface solid-phase reaction strategy was designed. Firstly, calcium acetate was uniformly coated on the surface of Fe-Si-Al soft magnetic alloy powder using hydrothermal method. Subsequently, Fe-Si-Al based soft magnetic composite cores were prepared by hot pressing sintering. The effects of sintering temperature and insulation layer phase transition on the morphology, microstructure, and magnetic properties of the prepared soft magnetic composite cores were studied. The results showed that calcium acetate was successfully coated onto Fe-Si-Al alloy powder surface by hydrothermal method, forming a core-shell heterostructure with the Fe-Si-Al alloy powder as the core and calcium acetate as the shell. This provided powder materials for subsequent preparation of soft magnetic composite cores. Raising sintering temperature eliminated internal pores within soft magnetic composite cores while promoting transition from calcium acetate to calcium carbonate to Al2O3?SiO2?CaSiO3, ultimately providing high-quality insulation. The insulating layer of the soft magnetic composite core prepared by high temperature sintering at 850℃ was dense and uniform, and the magnetic dilution effect was minimised. At 10 mT and 100 kHz, the soft magnetic composite core had the highest permeability (67.2), the lowest core loss (9.24×10-5 kW/cm3), and a relatively higher saturation magnetisation (129.0 emu/g), which had the best comprehensive performance, and provided a solution to restrict the reverse relationship between permeability and loss in traditional soft magnetic materials. Therefore, insulation methods based on thermal decomposition and oxidation of organic salt compounds are expected to be an important supplement to the magnetic property optimisation strategy of soft magnetic composite cores based on interfacial solid phase reaction engineering.

Research on the process of improving the grade of high-iron red mud from the reductive Bayer process by the alkali hydrothermal and complexation dissolution method

Zhipeng HU Ying ZHANG Shili ZHENG Yilin WANG Qiusheng ZHOU Pengcheng QÜ Xing ZOU

The Chinese Journal of Process Engineering. 2024, 24(10):  1208-1221.  DOI: 10.12034/j.issn.1009-606X.224013

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The resource utilization of red mud is of crucial importance for the sustainable development of the alumina metallurgical industry, and it has also been a major challenge that has long constrained the progress of aluminum metallurgical processes. The breakthrough of the reductive Bayer process has dramatically improved the magnetic separation of iron from red mud and allowed the production of high-iron red mud, which has built the foundation for the co-metallurgy of Fe metal and alumina. However, there are harmful impurities such as Al, Si, and Ti in the high-iron red mud produced from the reductive Bayer process, which have adverse effects on iron smelting. What's more, Fe and Ti are highly isomorphism replaced. This makes it difficult to separate titanium from iron in red mud. This study used high-iron red mud as the raw material and characterized its physicochemical properties. The removal of Al and Si from the red mud by alkali leaching was studied based on the solubility of sodium aluminosilicate in an alkali solution. Under the optimized conditions, their removal was satisfactory; the Si content in the leached red mud was less than 0.1wt%, and the Al content was about 0.21wt%. The occurrence of the stubborn phases of calcium aluminosilicate and alumogoethit determines the leaching conditions for Al and Si. Using the principle of complexation dissolution of Ti, researched the complexation dissolving of titanium from the alkali-hydrothermal treated red mud. The results showed that the mixed system of H2O2, ammonia, and citric acid was capable of complexation dissolving amorphous metatitanic acid, and 21% titanium in the alkali-treated red mud can be complexation dissolved. However, after the alkaline leaching process, a significant portion of titanium in red mud was not yet in a favorable form for complexation dissolution. More future work on the regulation of titanium form and complexation medium is needed.

Preparation of high-purity copper by electrochemical recovery of waste cupronickel in choline chloride-glycol deep eutectic solvent

Hongda LI Juanjian RU Mingqiang CHENG

The Chinese Journal of Process Engineering. 2024, 24(10):  1222-1229.  DOI: 10.12034/j.issn.1009-606X.224041

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Waste cupronickel is widely used in many fields, with the increasing demand and consumption of waste cupronickel, a large amount of waste copper alloy has been produced. Although the traditional wet process can remove some insoluble impurities and the working conditions are superior, the process is long and the energy consumption is high. Therefore, this work high-purity copper (Cu) was recovered from waste cupronickel by electrolysis separation at 363 K and 0.1~0.5 V cell voltage in choline chloride-glycol deep eutectic solvent (ChCl-EG DES) with the molar ratio of 1:2 as an electrolyte, waste cupronickel as an anode, and titanium sheet as a cathode. Electrochemical tests exhibited that Cu can be dissolved as monovalent Cu(I) into ChCl-EG DES, and the reduction of Cu(I) at the concentration range of 0.5~2.5 mol/L CuCl was a quasi-reversible process. The calculated Ea of the anode dissolution process was only about 28.361 kJ/mol, indicating that the dissolution process of Cu in ChCl-EG DES was controlled by diffusion. The anode polarization curve implied that Sn was dissolved into the solution first, while the dissolution potential of Ni and Fe was similar to that of Cu, and they were entered into anode slime. The electrolysis experiment showed that when the cell voltage increased, both the DC power consumption and the current efficiency increase accordingly. When the cell voltage was at 0.5 V, the current efficiency of electrochemical recovery of waste cupronickel was as high as 97.20%, and the DC power consumption was 216.94 kWh/t. At higher cell voltage (0.3~0.5 V), the morphology of cathode copper was irregular mass with a particle size of 30~50 μm, and the purity of copper can be obtained at the cathode at 0.4 V cell voltage was as high as 99.95wt%.

Performance analysis of flash cascade heat pump drying system with heat recovery

Huipeng YANG Kai YE Longxiang CHEN

The Chinese Journal of Process Engineering. 2024, 24(10):  1230-1240.  DOI: 10.12034/j.issn.1009-606X.224029

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Addressing the issues of traditional single-stage heat pumps whose efficiency deteriorates rapidly with increased temperature requirements and the significant energy waste caused by direct discharge of residual heat from auxiliary condensers, this work proposes a Heat Recovery Flash Evaporation Cascade Heat Pump Drying System (HR-FCHP) that leverages the benefits of low-temperature drying in the early stages of the process to enhance the external quality of materials. By incorporating the characteristics of a two-stage compression heat pump, this system couples the auxiliary condenser heat recovery with cascaded temperature drying. A thermodynamic model is established and validated using data from published literature. And a comprehensive thermodynamic analysis of the system is conducted to investigate the influence of key parameters on the operational efficiency of the proposed HR-FCHP system. Simultaneously, the proposed system is compared with a single-stage heat pump drying system (SSHP), a basic cascaded heat pump drying system (FCHP), and a parallel condenser heat pump drying system (PCHP) under the same operating conditions. To facilitate the validation of the energy-saving and drying efficiency of the proposed HR-FCHP system, an additional auxiliary condenser heat dissipation subsystem is incorporated into the three comparative heat pump subsystems, all of which feature a closed drying subsystem. This subsystem aims to recover and utilize excess heat for pre-drying the drying materials. The results indicate that the proposed HR-FCHP system has higher energy-saving and drying efficiency compared to the SSHP, FCHP, and PCHP systems. The coefficient of performance for heating (COPh) and specific moisture extraction rate (SMER) of HR-FCHP system are 5.40 and 4.31 kg/kWh, which are 53.85% and 65.77%, 33.00% and 20.73%, and 7.14% and 9.40% higher than the COPh and SMER of the SSHP, FCHP, and PCHP systems, respectively. Additionally, the HR-FCHP system has the lowest initial cost (CIC) at 66400 CNY, and its life cycle cost (CLCC) can be reduced by 69.86%, 40.92%, and 8.57% compared to SSHP, FCHP, and PCHP systems, respectively. This novel heat pump drying system can serve as a theoretical foundation for future experimental research and practical applications.

Research on the removal process and mechanism of aluminum/iron impurities from wet phosphoric acid through deep extraction

Youzhi DAI Ganyu ZHU Ziheng MENG Huiquan LI Chengjin XU Guoxin SUN Fang LI Lei HE Yongfang ZHANG

The Chinese Journal of Process Engineering. 2024, 24(10):  1241-1250.  DOI: 10.12034/j.issn.1009-606X.224056

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The presence of impurities in phosphoric acid hinders its application in downstream processes. The development of wet-process phosphoric acid deep purification technology enables the direct preparation of phosphate-based new energy materials through a simplified process, which represents the mainstream direction for industry advancement. The solvent extraction method was employed for the extraction and separation of Al and Fe impurities in wet-process phosphoric acid. The effects of different extractants, temperature, O/A ratio, time, and extractant content on the separation efficiency of Al and Fe impurities were investigated. Optimal conditions were determined as follows: N,N-N-octyl amine di (methylene phenylphosphonic acid) (OADMPPA) extractant, extractant content of 20wt%, time of 3 min, temperature at 25℃, O/A ratio of 1:1 and 3-stage cross-flow extraction. Under these conditions, the extraction rates for Al and Fe reached 54.5% and 99.6%. Consequently, the contents of Al and Fe impurities in phosphoric acid decreased from 0.857wt% and 0.175wt% to 0.717wt% and 0.015wt%. Additionally, the MER value reduced from 9.037% to 7.227%. Further optimization of stripping process of OADMPPA extractant loaded with Al and Fe was carried out, ammonium oxalate was identified as the optimal stripping agent. The optimized stripping conditions were as follows: 25℃, 5-stage cross-flow stripping, O/A ratio of 2:1, time of 15 min, and concentration of the stripping agent at 0.2 mol/L; the stripping efficiencies for loaded extractant Al and Fe reached 96.4% and 88.3%, effectively achieving their separation from the extractant phase. Finally, the mechanism behind Al or Fe extractants was investigated by stoichiometric calculation and Fourier infrared analysis during the extraction process. It was found that during this process, one molecule of Al combined with one-and-a-half molecules of OADMPPA extractant while one molecule of Fe combined with two molecules of OADMPPA extractant; functional groups involved in these interactions included P=O and P-O-H bonds. A competitive mechanism exists in the extraction process between Al and Fe, where Fe is more easily extracted.