Multistage Reactions Research Articles

Thermal-chemical conversion of sewage sludge based on waste heat cascade recovery of copper slag: Mass and energy analysis

Thermo-chemical conversion method can transform sewage sludge (abbreviated as SS) to bio-char with hydrogen-rich gas and has good prospects for development. In this research, copper slag was used as heat carrier and provide energy for conversion process of SS. A method of carbonization-activation waste heat cascade recovery technology system was designed. In this technology process, multi-stage endothermic chemical reactions absorb sensible heat from hot copper slag particles. Syngas, activated carbon (abbreviated as AC) and char are produced from SS. Mass and energy balance of this system were evaluated. The results showed that waste heat recovery efficiency and byproducts' additional value were improved by this method comparing with traditional water quenched method. Increasing heat quantity of carbonization process can improve system's energy recovery ratio. In theory, under the optimal condition (T2 = 700 °C, T3 = 200 °C), waste heat recovery ratio and exergy recovery ratio reach 90.8% and 94.9%, respectively.

Thermal stability of modified lithium-ion battery electrolyte by flame retardant, tris (2,2,2-trifluoroethyl) phosphite

With the increasing awareness of green energy, electric vehicles have become the future trend, with lithium-ion batteries (LIBs) regarded as the most suitable energy storage carrier. Therefore, more and more research topics are focused on LIBs, and all parties are working hard to improve the performance of LIBs. Yet, the safety concerns caused by the failure of LIBs cannot be ignored. LIBs themselves are energetic materials, and the causes of accidents often go through multistage irreversible reactions. Several studies have also pointed out that the electrolyte has a significant correlation with the response characteristics because, in the process of LIBs thermal runaway, the electrolyte participating in the oxidation of the entire battery leads to a considerable amount of heat and even runaway reaction as well. Accordingly, it is necessary to obtain a safer electrolyte by modification. In this study, a significant flame retardant (FR) additive, tris (2,2,2-trifluoroethyl) phosphite (TTFP), is used to suppress lithium-ion battery fires or even explosions and maintain typical battery performance. The performance of the electrolyte was tested by differential scanning calorimetry and thermogravimetric analyzer, and the electrolysis was examined on liquid flash point (FP), self-extinguishing time (SET), and conductivity. During the heating process, adding TTFP to the electrolyte effectively delayed the exothermic peak, reduced the amount of heat, improved the FP, and curtailed the SET. The hazard degree of the electrolyte under high-temperature environment was much lower than before adding the additives, and the additives were finally obtained. It can conclusively prove the safety of lithium batteries without lessening the practical performance of the batteries.

Improved antibacterial activity of hemp fibre by covalent grafting of quaternary ammonium groups.

In this study, a novel antibacterial hemp fibre grafted with quaternary ammonium groups (HF–GTA), were prepared by alkalization, oxidation, amination and quaternization multistage reactions. The chemical structure and micromorphology of the fibre were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and X-ray diffraction. The grafting and reaction mechanism proved to be successful, which indicated that the grafting reaction primarily occurred on the hydroxyl group of cellulose and hemicellulose in the hemp fibre, where it retained good fibrous morphology, thermal stability and hygroscopicity. HF–GTA exhibited the best antibacterial activity, where the antibacterial ratios against Escherichia coli and Staphylococcus aureus were 95.41% and 99.64%, respectively. Even after washing 30 times, the antibacterial activity was retained at 89.78% and 91.12%, indicating that HF–GTA was endowed with good washing resistance. The antibacterial activity was owing to the electrostatic reaction reducing the electrochemical potential on the cell membrane, leading to the release of cytoplasmic substances and the dissolution of cells. This study is significantly important for guaranteeing textile quality and preventing disease transmission.

Application of oscillating chemical fingerprint technology combined with mathematical analysis method in quality control analysis of traditional Chinese medicine and food

Oscillating chemical fingerprint is a nonlinear dynamic fingerprint technology that reflects the overall redox activity of the entire system based on potential-time changes in multi-stage chemical reactions. This article summarizes the application of oscillating chemical fingerprint technology combined with mathematical analysis method in the qualitative and quantitative analysis of traditional Chinese medicine and food in recent years, including similarity analysis, principal component analysis, cluster analysis and other qua-litative analysis methods, as well as linear, logarithmic, exponential, polynomial, multivariate analysis and other quantitative analysis methods, so as to provide meaningful information for further quality control analysis of the oscillation chemical fingerprint technology in the field of traditional Chinese medicine and food.

Stationary Kinetic Structures of Chemical Reactions

Stationary structures corresponding to non-stationary experiments with different initial conditions have been established for multistage reactions. Such structures are formed from various pairs of combinations of non-stationary reagent concentrations, and they remain constant over time in the course of reaction. They form lines of different curvature intersecting at one stationary point on the graphs of their concentration dependences for any reagent in one of the experiments. The stationary structures constructed in this way are specific for various reaction mechanisms; they supplement known relaxation characteristics and can be used to identify the mechanisms of chemical reactions based on the data of non-stationary experiments.

Viscous fluid flow in a microchannel with hydrodynamic traps

Simulation of creeping flows in complex three-dimensional domains is crucial for microfluidics applications, creating multipurpose microfluidic devices, which are used, for example, to study multistage chemical reactions and as analytical devices in medicine.In this work we study the features of the incompressible viscous fluid flow in a flat microchannel with a nontrivial internal structure (the hydrodynamic traps of various configurations) under the constant pressure drop.The three-dimensional boundary element method, improved by utilization high-efficient fast multipole method and heterogeneous computational workstation, was used in numerical simulation.We studied the flow pattern around C-shaped hydrodynamic traps distributed in a flat microchannel and consisting of five cylindrical elements of the same size. Such geometry is widely used in microfluidic devices for fixing particles in the flow, for example, biological objects during tests in medicine. The influence of the distance between the rows of traps on the flow pattern and distribution of the longitudinal and transverse components of the flow velocity was considered.

Method for Solving the Inverse Problem of the Chemical Kinetics of Multistage Reactions

A method for solving the inverse problem of chemical kinetics based on the data of non-stationary experiments for multistage reactions is described. The method is based on the use of splines, which take into account the relaxation features of reactions with monotone kinetics. Examples of using the method to determine the intervals of physical values of the rate constants of two- and three-stage reactions are given. The influence of the spline structure on error in the determination of rate constants of stages is estimated. The effectiveness of the method for solving the inverse problem of chemical kinetics for multistage reactions is shown with consideration for errors in the determination of experimental data.

A Method for Solving the Inverse Problem of Chemical Kinetics for a Nonisothermal Gradientless Reactor Based on Steady-State Data

A method has been presented for solving the inverse problem of chemical kinetics based on steady-state experimental data with different initial conditions (multiexperiments) taking into account measurement errors in an open nonisothermal gradientless reactor. Examples of using the method to determine the intervals of the physical values of rate constants for the stages of multistage nonlinear reactions have been given. The effect of measurement errors on the accuracy and stability of the method has been evaluated.

Inhibitory effects of developed composite flame retardant on bituminous combustion and volatile emissions

Bituminous materials release plenty of heat and hazardous volatiles when exposed to high temperature. To develop a sustainable and efficient composite flame retardant (CFR) of bituminous materials, new compositional formulation proportions of selected Ca–Al hydrotalcite (CAHC), ammonium polyphosphate (APP), coated red phosphorus (CRP) and expanded vermiculite (EV) in the prepared CFR were confirmed. Then the inhibitory effects of CFR on non-isothermal combustion kinetics characteristics of bitumen and the dynamic release processes of various volatile constituents were discussed using thermogravimetry/differential scanning calorimeter-mass spectrometer-Fourier transform infrared spectroscopy (TG/DSC- MS-FTIR) combined approach. Test results suggest that the combustion processes of bitumen and CFR bitumen mainly include obvious multistage exothermic reactions. When the heating rate is elevated, the incomplete combustion of bitumen and CFR bitumen is increased, and more heat and volatiles are emitted. Further, as the bituminous temperature is gradually raised, the CAHC, APP, CRP and EV in added CFR are decomposed in turn to inhibit the multistage combustion process of bitumen, showing comprehensive and synergistic flame retarding effects due to dilution, cooling, and insulation. Therefore, the combustion of bituminous four components is correspondingly inhibited by the matched flame retardant in CFR so that the bituminous thermal stability is obviously improved by added CFR. Additionally, the CFR produces thicker intumescent layer on bitumen, which insulates bitumen with oxygen, and decreases the volatile release and molten droplet formation. Fewer macromolecular volatiles are emitted from CFR bitumen than those from bitumen. Moreover, the dynamic release process of various volatile constituents during the bituminous combustion is efficiently suppressed by CFR. The developed CFR plays an important role of flame retarding and smoke suppressing functions, providing an efficient and green flame retardant for bituminous materials when exposed to a fire.

The current state of the problem of manufacture and using synthesis gas based on the carbon gasification reaction. Part 2. Mathematical models of the physical fields of the carbon-containing materials gasification

The first part of the article showed the practical feasibility and feasibility of partial or full replacement in the energy and energy-intensive industries of natural gas for synthesis gas resulting from the gasification of solid fuels. At the same time, one of the most appropriate ways to determine the structural, technological and environmentally friendly parameters of the gasification process, especially on an industrial scale, is the mathematical modeling of this process and related equipment. This allows you to abandon the costly field experiments and save significant material, energy and human resources.An analysis of mathematical modeling of the processes of generation and practical use of synthesis gas from solid and liquid fuels showed that for the numerical analysis of gasification processes, for the most part, two models are used: continuum-discrete (Euler-Lagrange) and continuum-continuum (Euler-granular Multіphase). In the continuous-discrete model, the Computer Fluid Dynamics (CFD) approach is used to describe the behavior of the gas mixture of reaction components, and for solid particles, the Discrete Phase Models (DPM) or Discrete Element Methods (DEM) are used. In the continuum-continuum model, the CFD approach is used to describe the behavior of both the gas and pseudo-solid phases. Moreover, for the solid phase, on the basis of the kinetic theory of granular flow, additional equations are written. Turbulent gasification modes are described by the Navier-Stokes equations averaged over Reynolds and Favre using standard or realizable models.It is also shown that in the study of gasification processes, an important problem is chemical kinetics and mechanisms that are responsible for combustion processes and can contain a large number of reaction components and elementary reactions. To solve the corresponding problem of chemical kinetics, two main approaches are used: the first is based on detailed multi-stage chemical reactions, and the second is based on the use of simplified global reactions with a significantly smaller number of both components and reactions.In the published works, specialized equipment for the gasification of solid carbon-containing materials is considered and no attention is given to the modernization of existing industrial equipment in order to produce synthetic gas. At the same time, the kinetics of chemical gasification reactions in different studies differs significantly. First of all, this concerns the order of chemical reactions, activation energy, as well as the values and dimensions of the preexponential factors of the kinetic equation Arrhenіus. It is also shown that in a number of existing mathematical formulations of problems there are certain inaccuracies and even gross errors. All this makes the direct use of existing models very problematic.

Гетероциклічні ароматичні аміни як критерій безпечності м`ясних та рибних продуктів

Against the background of adverse environmental conditions in Ukraine, experts in the field of medicine, food hygiene note the raising importance of various nutritional factors in increasing the risk of developing cancer. A number of compounds resulting from protein denaturation during the heat treatment of meat and fish products can pose a high risk. Such compounds include heterocyclic aromatic amines (HAA) i.e. substances that, in extremely low concentrations, can carry out mutagenic and carcinogenic effects on the human body. Aim of the Research. To analyse studies from available sources of information about the likelihood and conditions of the formation of chemicals hazardous to human health in foods of animal origin during thermal cooking. Methods and Materials. Review and analysis of scientific publications based on the results of experimental studies of European, American and Japanese scientists. Results and Discussion. Studies have established that in the process of thermal cooking of food products of animal meat, poultry, fish, HAA are formed and accumulate as a result of complex multi-stage chemical reactions with the obligatory participation of amino acids, sugars, creatine and creatinine, which is its cyclic form. The formation of mutagenic HAA is affected by a number of conditions. For example, the accumulation of heterocyclic aromatic amines in fried meat products is most affected by the temperature of the surface of the pan and the outer layer of meat, the duration of frying, the degree of meat chopping, the presence of breading, pickling, the addition of onions to the chopped meat. Conclusions. Taking into account that the diet of more than 40% of the population includes products containing HAA, the development and justification of safety criteria for meat and fish products concerning the content of heterocyclic aromatic amines as well as the development of ways to prevent their formation form an urgent problem. The following tasks must be solved as priorities: – to develop and standardize methods for the determination of HAA in various types of food products; – to conduct studies of the content of HAA in meat and fish products and in culinary products; – to study the influence of various methods of thermal cooking on the accumulation of HAA in finished products made from meat and fish; – to study the effect of the raw materials used and production technologies on the accumulation of HAA in food products; – to optimize the formulae of meat and fish products and their production technologies in order to minimize the number of HAA formed in the finished product; – to justify the acceptable levels of HAA in food products and to develop safety criteria for meat and fish products concerning the content of HAA on the basis of clinical and laboratory studies. Key Words: heterocyclic aromatic amines (HAA), meat products, fish products, thermal cooking, safety.

SOLVING INVERSE PROBLEM OF CHEMICAL KINETICS WITH USE OF CUBIC SPLINES

A simple effective method for solving the inverse problem of chemical kinetics based on non-stationary experiments for multistage reactions occurring in an isothermal reactor of ideal mixing is described. The idea of the method is based on taking into account the distinctive features (informativeness) of different fragments of relaxation curves for chemical reactions with arbitrary (non-monotonic) kinetics and their as accurate approximation as possible. For this purpose, non-linear (cubic) splines are used to describe different informative fragments of relaxation curves, which allow to approximate and interpolate experimental data as accurately as possible. An additional advantage of cubic splines, from the point of view of the implementation of the described method, is their continuity at all given points up to and including second-order derivatives (smoothness). This allows us to calculate with good accuracy not only the concentration of reagents, but also the instantaneous rate of change at any time. The consequence of this is the possibility of a sufficiently accurate solution of the inverse problem based on the data of non-stationary experiments. The correctness of the mathematical model used and the stability of the method were tested using variations of the original data. An example of using the method for determining the intervals of physical values of the rate constants of the stages of a two-stage reaction is given. The influence of the method of selecting the reference points (structure) of the spline and measurement errors (noise) of experimental data on the error of determining the speed constants of the stages is estimated. The efficiency of application and good accuracy of the method for solving the inverse problem of chemical kinetics of multistage reactions occurring in non-gradient systems with taking into account of noise is shown.

Intermediates of the Autocatalytic Reaction of the Formation of a Chromophore in a Green Fluorescent Protein

The autocatalytic formation of a chromophore in a green fluorescent protein, which is actively used as a marker for visualizing processes in living systems, is an important example of multistage reactions in protein macromolecules. The kinetic, spectral, and X-ray structural experimental studies and supercomputer calculations by molecular modeling methods are devoted to the study of intermediates of the elementary reaction stages, which are grouped into cyclization and oxidation blocks. The article analyzes the results, compatible with the experimental data, of the structure of intermediates of the reactions of chromophore formation for the native protein form obtained through computer modeling, with the aim of including this information in the database of the reactions’ intermediates in enzymatic reactions.

Comparative study of fast pyrolysis, hydropyrolysis and catalytic hydropyrolysis of poplar sawdust and rice husk in a modified Py-GC/MS microreactor system: Insights into product distribution, quantum description and reaction mechanism

Fast pyrolysis, hydropyrolysis and catalytic hydropyrolysis are three important methods to produce bio-oil from biomass and are of great interest to researchers. In this research, the comprehensive study of pyrolysis, hydropyrolysis and catalytic hydropyrolysis of poplar sawdust and rice husk was investigated in a modified laboratory Py-GC/MS microreactor system. Rh/ZrO2 (0.5 wt %) was prepared and applied in the catalytic hydropyrolysis process. An evaluation system including estimating method of product selectivity, the calculation method of O/C and H/C ratio, deoxygenation extent (DE) and hydrogen-loss extent (HLE), was established to fully measure the deoxygenation effect. The Rh/ZrO2-assisted catalytic hydropyrolysis showed a good deoxygenation effect as O/C ratios (0.10 for poplar sawdust, 0.11 for rice husk, respectively) are comparable to that of the reported upgraded bio-oil by hydrodeoxygenation (HDO). The highest hydrocarbon selectivity of 49.14% and DE of 87.6% were obtained in catalytic hydropyrolysis of poplar sawdust. For rice husk, the hydropyrolysis process gained a similar DE (82.7%) to that of the catalytic HyPy (83.7%), because rice husk with high ash content (19.4 wt %) contains a large number of mineral elements that are likely to form a self-catalysis effect. The reaction mechanism was further inferred according to product distribution and quantum calculation of oxygen-containing products, suggesting that Rh/ZrO2-assisted hydropyrolysis was accomplished by multistage reactions, involving initial pyrolysis of raw biomass and further deoxygenation of the pyrolysis intermediates. Moreover, this work can also provide a proven methodology and theoretical supports for future studies on catalytic hydropyrolysis of biomass.

Autonomous Kinetic Invariants of Linear Chemical Reactions

A method has been developed for calculating the exact autonomous kinetic invariants of multistage linear chemical reactions occurring in a gradientless isothermal reactor via any number of elementary stages and involving an arbitrary number of reagents within the framework of mass-action law. These invariants are functions that remain strictly constant throughout the reaction (i.e., are time-independent), although they depend on the nonequilibrium reagent concentrations measured in two experiments with different initial conditions (dual experiments). For the dynamic models of linear reactions, one can always find general and particular analytical solutions expressed explicitly in terms of the initial conditions. The idea of the method is based on choosing the initial conditions that allow the nonequilibrium reagent concentrations to be expressed in terms of constant kinetic parameters (stage rate and flow rate constants). An applicability criterion of the method was formulated. The number of different invariants was shown to be equal to the number of reagents. The relations obtained in this study were used to investigate the relaxation properties of multistage linear reactions occurring in closed and open isothermal systems. The invariant curves found for these reactions were compared with the concentration curves measured in two nonequilibrium experiments throughout the transition process. For these reactions, the time dependences of the invariants remained strictly constant, while the reagent concentrations continuously changed (including nonmonotonously) during the reaction. The results give new insight into the relaxation of linear chemical reactions and can be used to solve the inverse problems of chemical kinetics under the conditions of an isothermal perfect-mixing reactor.

One pot menthol synthesis via hydrogenations of citral and citronellal over montmorillonite-supported Pd/Ni-heteropoly acid bifunctional catalysts

Menthol synthesis is possible through citral and citronellal hydrogenations via following multistage chemical reactions such as hydrogenation and cyclization. This research mainly focuses on a design of selective, active and cost-effective metal-acid (bifunctional) catalysts for menthol production via citral and citronellal hydrogenations. More specifically, Pd and Ni metals were impregnated over acidic support (e.g., hetero-poly acid supported montmorillonite, HPA_MM). The prepared catalysts were characterized by BET, pyridine adsorption and amine titration methods. Some of the most important parameters such as metal type and loading; applied pressure and reaction time have been investigated throughout this work. The obtained results reveals that the 8 wt% Ni-HPA-MM catalyst (Cat-5) has produced 63% menthols (initial reaction rate 0.126 mmol/min) from citral hydrogenation (80 °C, 1.0 MPa) within 24 h. Similarly, during lower applied pressure (0.5 MPa), the production of menthol was significantly improved (approximately 98% of menthol, initial reaction rate ~ 0.138 mmol/min) with the application of 8 wt% Ni-HPA-MM catalyst (Cat-5) in citronellal hydrogenation. Higher menthol selectivity was achieved from both reactions (citral and citronellal hydrogenation) which might be due to the presence of strong Lewis and medium Bronsted acid sites.

Improved solubility of asymmetric tetraethynylporphyrin derivatives for solution-processed organic solar cells

Abstract Asymmetric magnesium tetraethynylporphyrin derivatives bearing two diketopyrrolopyrrole (DPP) units and two different aryl units were synthesized by multistage Sonogashira coupling reactions. According to saturated UV–Vis–NIR spectra, the solubility of the asymmetric porphyrin derivatives was superior to that of symmetric porphyrin derivatives. Frontier orbital energies were investigated in the solution state by differential pulse voltammetry and in the solid state by photoelectron yield spectroscopy and UV–Vis–NIR spectroscopy. Time-dependent density functional theory calculations were carried out to simulate the UV–Vis–NIR absorption spectra and revealed splitting of the Q band into two bands at 712 nm and 650 nm. The thickness of active layers in solution-processed organic solar cells was influenced by the solubility of the porphyrin derivatives. When the compound with the highest solubility was used (2d), the film thickness was 215 nm, which is larger than-the thickness of ∼120 nm reported for symmetric porphyrin derivatives. Also, the short-circuit current density (JSC) was influenced by solubility, especially for compound 2d, compared with other asymmetric compounds 2a–c. The optimized device conditions using 2d and PC61BM gave JSC of 14.86 mA/cm2, open-circuit voltage of 0.69 V, fill factor of 0.47, and power conversion efficiency of 4.84%.

Thermogravimetric and infrared spectroscopic study of bituminous coal spontaneous combustion to analyze combustion reaction kinetics

Thermogravimetry and in-situ Fourier transform infrared spectroscopy were used to study spontaneous combustion in bituminous coal. The results show that the coal’s spontaneous combustion can be divided into five stages, Stages I–V. Qualitative analysis of changes in the molecular functional groups allowed the chemical reactions in each stage to be deduced. Through semi-quantitative calculations of alkyl side bond length, and the degrees of aromatic condensation and oxygen enrichment degree, the critical temperature T1, mass maximum temperature T2 and ignition temperature T3 were identified as important characteristic temperature points for spontaneous combustion which shows that coal spontaneous combustion is produced by multi-stage reactions. Isoconversional calculations found that the apparent activation energies of the oxygen absorption and weight gain and slow chemical reaction stages gradually increased as the temperature increased but the apparent activation energy decreased after T3. Calculations also show that different stages have different reaction mechanism functions. Recognizing that these stages exist is important for deepening our understanding of coal oxidation reactions.

Thermal behaviors and harmful volatile constituents released from asphalt components at high temperature.

Asphalt binder releases lots of heat and harmful volatiles at high temperature. To further understand thermal behaviors, dynamic release and toxic constituents of emitted volatiles during the combustion of asphalt binder, such fractions as saturates, aromatics, resins and asphaltenes (SARA) were first prepared. Thermal behaviors, volatile constituents and combustion residue microstructures of SARA fractions are discussed. Results indicate that polymerization degree of asphalt binder is high and the content of polycyclic aromatic compounds is large. Combustion processes of resins and asphaltenes only show single-stage exothermic reactions, but other two fractions present obvious multi-stage combustion reactions. As the heating rate is raised, the incomplete combustion of SARA fractions is increased, and more volatiles are released. Main volatiles released from SARA fractions are inflammable, toxic, corrosive or explosive compounds, and such common volatiles as acetaldehyde and propane are released from each SARA fraction. More toxic volatiles are released at combustion stage I, but macromolecular volatiles are mainly released at stage II. Volatile release behaviors of saturates and aromatics are more obviously affected by the heating rate. Combustion residues show more intact morphologies from saturates to asphaltenes, and mainly contain C, O and S elements. Asphalt binder is hazardous material at high temperature.

Compositional variations of granitic rocks in continental margin arc: Constraints from the petrogenesis of Eocene granitic rocks in the Tengchong Block, SW China

In order to address the causes of compositional variations of crust-derived granitic rocks in continental margin arc, we focused on the petrogenesis of Eocene granitic host rocks with enclosed MMEs, associated metagabbro, fine-grained quartz-diorite in Xima-Tongbiguan area, the Tengchong Block, which is a continental margin arc related to the subduction of Neo-Tethys. Both the Eocene granitic and mafic rocks are characterized by gradual increment in enriched compositions, such as K, Rb, Th, LREE, initial 87Sr/86Sr, εNd(t), and εHf(t), but decreasing Pb isotopic ratios from the west to the east of the Tengchong Block.Zircon UPb age data of granitic host rocks, MMEs, metagabbro and fine-grained quartz-diorite reveal a similar age range of 55–50 Ma. The lithologies, zircon Hf compositions, geochemical and isotopic signatures of host granitic rocks show that the origin of these host rocks are mainly controlled by magma mixing between felsic and mafic magma. The products of the mafic magma are dominated by metagabbro, fine-grained quartz-diorite and MMEs enclosed in granitic rocks, which are all resulted from the reaction and mixture between different mafic magmatic products and felsic magma. The metagabbros could be the products of felsic magma mixing with early crystallized mafic magma, and the fine-grained quartz-diorites could be the products of felsic magma mixing with crystal-rich mafic magma, and the MMEs could be the products of felsic magma mixing with crystal-poor mafic magma or melt. The metagabbro has positive εHf(t) values of 1.8 to 10.9, which could provide the relative primitive LuHf isotopic compositions of mafic magma, indicating that the mafic magma is derived from a depleted mantle. The host granitic rocks have negative εNd(t) values of −5.2 to −6.5, indicating that the felsic magma is derived from partial melting of an ancient mafic lower crust. Furthermore, there are excess reactions after magma mixing between the mafic and felsic magma, such as multi-stage reactions between solidified MMEs and felsic magma, and the disaggregation of MMEs, finally resulting in the basification of felsic magma. Magma mixing is therefore the main mechanism of the formation of granitic rocks in the Tengchong Block. The compositional variation of intermediate to acid igneous rock in a continental margin arc is likely dominated by the characteristics of mafic magma because the intermediate to acid igneous rock is derived from mixing of crust-derived granitic and different mantle sources-derived mafic magma.