Sulfuric Acid System Research Articles

Proton transport mechanisms in aqueous acids: Insights from abinitio molecular dynamics simulations.

The solvation and transport of protons in aqueous solutions of phosphoric acid (PA), sulfuric acid (SA), and nitric acid (NA) were studied using abinitio molecular dynamics simulations. Systems with acid-to-water ratios of 1:1 and 1:3 were examined to understand the similarities and differences in transport mechanisms. The solvation structure of H3O+ in these systems is similar to that in slightly acidic water, with variations in the strength of hydrogen bonds (H-bonds) accepted by acid molecules. In aqueous PA systems, strong H-bonds between PA molecules are slightly affected by water, leading to significantly greater H3O+ diffusion compared to aqueous SA and NA systems. This enhanced diffusion is attributed to the participation of PA molecules in H3O+ transport, where the PA molecule can shuttle a proton for H3O+, facilitating a large displacement via collective proton hopping. This shuttling mechanism is prominent in aqueous PA but rare in aqueous SA and absent in aqueous NA. Moreover, the decomposition of H3O+ diffusion into vehicular and structural components indicates that the higher diffusion in aqueous PA is primarily due to the structural mechanism with the aid of PA molecules. In the aqueous NA systems, the vehicular diffusion is dominant at low water contents and the increase in water content improves the structural diffusion by forming connected H-bonds within water molecules. Our findings elucidate the role of acid molecules in proton transport within their aqueous solutions, thereby advancing the fundamental understanding of proton transport mechanisms.

Environmentally friendly non-saponification solvent extraction and separation process for RE(III) (RE = Eu, Gd and Tb) in acetic acid solution using HEHEHP/n-heptane

The key to achieving sustainable metal extraction development is to avoid the generation of high-salt wastewater from the source. Here, a new system for the extraction and separation of lanthanide elements Eu(III), Gd(III) and Tb(III) from the acetic acid solution using HEHEHP (2-ethylhexyl hydrogen-2-ethylhexylphosphonate) was studied. The corresponding parameters including contact time, HEHEHP concentration, concentrations of rare earth metal ions and acetic acid in the initial solution, aqueous/organic phase volume ratio (R(A/O)), and temperature were considered to optimize the conditions for the separation of different rare earth elements. The results showed that the separation coefficients of Tb(III)/Gd(III) and Gd(III)/Eu(III) in the acetic acid system were approximately 6.2 and 1.7, with HEHEHP of 0.15 mol/L and R(A/O) of 2:1, and the extraction efficiency of RE(III) reached approximately 73.1%, which was higher than that in the hydrochloric acid and sulfuric acid systems. The mechanism associated with the extraction reaction was evaluated and discussed by the maximum loading capacity method, chromatographic analysis, and FT-IR spectrometric analysis. The mechanism followed a cation exchange reaction and acetic acid did not participate in the extraction process. The feasibility of the separation of Tb(III) from Eu(III) and Gd(III)was also given in terms of the separation coefficients between different elements at different extraction conditions. Since saponification is not necessary in the acetic acid extraction system, it can considerably reduce wastewater discharge to the ecological environment from the source.

Experimental and DFT studies on using Fenton reagent as oxidant to enhance the leaching of cuprite in sulfuric acid system

The utilization of a Fenton reagent was implemented within this investigation to facilitate the oxidation of cuprite with the purpose of enhancing its leaching efficacy in sulfuric acid. The concentration of 0.007 mol/L Fenton reagent increased the extraction rate of cuprite from 69.43 to 91.53 %, which increased by 22.1 %. The XPS, AFM, SEM–EDS, and ToF-SIMS results showed that the leaching process of cuprite significantly enhanced its oxidation and the conversion of Cu(I) species to Cu(II) species by the Fenton reagent；Electrochemical tests revealed that as the concentration of the Fenton reagent increased, the strength of the oxidation reaction increased. After the adsorption of hydroxyl radicals (•OH) onto the cuprite surface, the population of Cu12-O12 decreased notably from 0.45 to 0.26, concomitantly with an expansion in bond length from 1.824 Å to 1.930 Å. As the population of Cu12-O7 decreased from 0.39 to 0.05, the bond length exhibited a notable increase from 1.849 Å to 2.241 Å. The findings indicated that following the adsorption of •OH on the cuprite (111) surface, structural instability ensued. The EPR test confirmed that the introduction of Fenton reagent into the reaction system generated •OH. Simultaneously, with the extension of reaction time, the concentration of •OH in the system decreased, resulting in a reduction of the signal peak intensity.

Copper leaching from complex chalcopyrite-rich ores: Utilizing mechanical activation and wastewater-based sulfuric acid system

Complex chalcopyrite-rich ore is crucial in global copper resources, but is highly refractory in conventional sulfate leaching system. In this paper, we explore the leaching of complex chalcopyrite-rich ores employing a mechanically activated pretreatment combined with wastewater with high concentrations of chloride. The investigation delves into various parameters, including reaction temperature (60 to 90 °C), sulfuric acid concentration (0.005 to 2.0 M), chloride concentration (0 to 1.5 M), liquid/solid ratio (0 to 200), stirring speed (100 to 580 rpm), leaching time (0 to 4 h) and grinding time (0 to 7 h), to evaluate their impact on copper recovery from complex chalcopyrite-rich ores. Furthermore, a comprehensive kinetic analysis of copper leaching behavior was studied, encompassing specific surface area, amorphization degree, grain size, and microstrain. In the sulfuric acid system utilizing wastewater, the presence of mechanical activation and chloride content enhances copper leaching while mitigating the passivating effect of elemental sulfur. Notably, following a leaching period of 4 h at 80 °C, the copper leaching efficiency remarkably reached 89.46 %. In addition, kinetic analysis of copper leaching at temperatures ranging from 60 to 90 °C via a shrinking core model with R2 > 97 %, indicates that the leaching process of copper is primarily governed by solid product layer diffusion, with an activation energy of 54.32 kJ/mol. These findings highlight the efficacy of the proposed approach in optimizing copper recovery from complex chalcopyrite-rich ores, offering insights into the underlying mechanisms driving the leaching process.

Mechanism and kinetics study of vanadium leaching from landfilled metallurgical residues by ultrasonic with ozonation enhancement in a low-acid medium

Landfilled metallurgical residues are valuable raw materials for the recovery of strategic vanadium resources. However, efficient separation of vanadium from these residues is challenging due to its strong oxidation resistance and coating within silicate inclusions. To address this issue, this study proposes an enhanced leaching process utilizing the synergistic effect of O3-catalyzed ultrasonic field in a low concentration sulfuric acid system. Results show that following a 10-minute O3 and ultrasonic treatment, the direct leaching rate of vanadium experienced a remarkable 46.7 % increase. Quenching experiments revealed a hierarchical order of active species within the reaction process:⋅OH >⋅O2−> H+, with⋅OH oxidation exhibiting the most pronounced capacity for disrupting the inclusion structure. Electron Paramagnetic Resonance analysis indicated that the highest⋅OH yield arose from the combined application of ultrasound and ozone. Kinetic investigations demonstrated that the vanadium leaching process is governed by interfacial chemical reactions. The activation energy of vanadium oxidation leaching under ultrasonic-O3 conditions was determined to be 40.41 kJ/mol, representing a 20.19 % reduction compared to ultrasonic conditions alone. Through the integration of analysis, characterization, and comparative evaluations, it was discerned that the synergistic impact of ultrasonic and ozone treatments significantly enhances the breakdown of silicate inclusions by low-concentration HF, particularly in the conversion of SiOSi bonds into SiOH bonds and SiF bonds. In summary, the refined leaching methodology incorporating ozone catalysis in conjunction with ultrasonic treatment provides a new idea for the separation and extraction of refractory residual vanadium.

Numerical Simulation Study of Gas-Liquid Two-Phase Flow in a Pressurized Leaching Stirred Tank

The gas-liquid flow and oxygen content in a pressurized leaching stirred tank significantly influence the chemical reaction rates, while the specific dynamics of gas-liquid flow in the sulfuric acid system remain largely unexplored. In this study, a mathematical model of gas-liquid flow within a stirred tank is developed using the Euler-Euler approach, with the turbulence and drag force models being validated against experimental data. Utilizing this validated and reliable model, this study investigates the impacts of the sulfuric acid concentration, baffles, air inlet velocity, and bubble diameter on the flow field and gas holdup in a two-phase system consisting of a sulfuric acid solution and oxygen. The findings indicate that introducing a specific concentration of sulfuric acid decreases the solution velocity and increases the gas holdup within the tank. However, once the sulfuric acid concentration reaches a certain threshold, further increases have a diminished effect on the gas-liquid phases. The installation of baffles enhances the turbulent kinetic energy and increases the gas holdup while only resulting in a minimal 1.2% increase in power consumption. Additionally, the inlet velocity and bubble diameter have a relatively minor impact on the tank’s flow field. However, increasing the inlet velocity significantly boosts the gas holdup, whereas an increase in the bubble diameter marginally reduces it. Furthermore, introducing a sulfuric acid solution into the tank can enhance the gas holdup when the gas inlet velocity is low. Conversely, when the gas inlet velocity is high, the addition of sulfuric acid results in a decrease in the gas holdup. The conclusions from this study contribute to enhancing the mixing effectiveness and oxygen content within the tank, providing a substantial theoretical basis for optimizing the design and operating conditions of pressurized leaching stirred tanks.

Synthesis of polyacrylate-divinylbenzene hydroxamic resins and its gallium adsorption performance in sulfuric acid solution

In this study, the adsorption behavior of gallium ions on a synthesized hydroxamic acid resin from sulfuric acid solution was investigated, aiming to recover Ga directly from pressure leaching solution in zinc hydrometallurgical plant. Hydroxamic acid chelating resin (HA-PDR) was prepared by introducing hydroxamic acid groups into the pre-made polyacrylate resin (PDR) with methyl ester group through hydroxylamine reaction. Polyacrylate-divinylbenzene hydroxamic resins with a nitrogen content of up to 3.85 % were obtained at a divinylbenzene (DVB) content of 13 % and an optimal raw material ratio of NH2OH·HCl: NaOH: −CH3 = 4:4.5:1 (molar ratio). The obtained materials was characterized using FTIR, XPS and SEM to verify the successful introduction of hydroxamic acid groups. The results of adsorption experiments showed that the adsorption capacity of 27.65 mg/g could be obtained with a chemical, multilayered, and heterogeneous adsorption process, and film diffusion and intra-particle diffusion rate controlled mainly the adsorption efficiency. It has been proven that polyacrylate-divinylbenzene hydroxamic resins has extremely high adsorption selectivity for gallium in sulfuric acid solution, and the desorption effect is obvious, which can be applied promisingly in the industrial development of gallium extraction technology from zinc leaching residue in sulfuric acid system.

Feasible route for the regeneration of cathode materials from spent lithium-ion batteries via reduction leaching and in-site precipitation

With the goal of carbon neutrality, increasing end-of-life spent lithium-ion batteries (LIBs) is inevitable owing to the rapidly growing number of electric vehicles worldwide, which brings management and environmental problems. Nevertheless, the scarcity of valuable metals used in LIBs and the potential value of recycling them have attracted increased interest in recovering spent LIBs. The traditional methods for recycling spent LIBs, pyrometallurgy, and hydrometallurgy cause energy waste and environmental problems. Herein, green reagents, ascorbic acid, is introduced to reduce the amount of strong acid and help in-site precipitate the ternary precursor in this novel process for the recovery of spent LiNi0.5Co0.2Mn0.3O2 (NCM523). A reduction reaction caused by ascorbic acid occurs on the surface of the material, determining the chemical reaction that controls the leaching process and enhances leaching efficiency. The ternary precursor is formed in-site by oxidative precipitation in the leaching solution, which exists ascorbic acid. The regenerated NCM523 shows a high discharge capacity (158.5 mAh g−1 at 0.1C), and the capacity retention rate is 83.7% after 100 cycles. This ascorbic acid coordinated leaching in the sulfuric acid system following in-site precipitation is an environmentally friendly treatment for spent LIBs, which has the potential to be applied in the industry.

Optimization of Synergistic Leaching of Valuable Metals from Spent Lithium-Ion Batteries by the Sulfuric Acid-Malonic Acid System Using Response Surface Methodology

A new environmentally friendly and economical recycling process for extracting metals from spent lithium-ion batteries (LIBs) using sulfuric acid and malonic acid as leaching agents is proposed. By applying Box-Behnken design (BBD) and response surface methodology (RSM) optimization techniques, the global optimal solution of the maximum leaching rate of metals in spent LIBs is realized. The results show that under the optimal conditions of 0.93 M H2SO4, 0.85 M malonic acid, liquid/solid ratio of 61 g·L–1, the temperature of 70 °C and 5 vol% of 30% H2O2, 99.79% Li, 99.46% Ni, 97.24% Co and 96.88% Mn are recovered within 81 min. The error between the theoretical value and the actual value of the metal leaching rate predicted by the regression model is less than 1.0%. Additionally, the study of leaching kinetics reveals that the leaching process of Li, Ni, Co, and Mn in spent cathode materials was affected by the synergistic effect of interfacial mass transfer and solid product layer diffusion. Economic analysis reveals that evaluation index should be fully considered when formulating recovery processes for different metals. This process can reduce the environmental risks of heavy metal disposal, and allow the reuse of metals recovered from spent LIBs.

Highly selective separation of germanium from sulfuric solution using an anion exchange D201 × 7 resin with tartaric acid

Germanium (Ge) exhibits excellent optical and electrical properties. Due to the low reserves of Ge and lack of independent mineral resources, zinc refinery residues have become an important source of Ge. In this work, a D201 × 7 resin has been employed in the selective separation of Ge from a sulfuric solution using tartaric acid as a complexing agent. In the sulfuric acid system, Ge(OH)4 was converted to an anionic complex [GeO2(OH)2C4H4O4]2− at a 1:1 tartaric acid to Ge molar ratio. The anion exchange D201 × 7 resin adsorbed the Ge tartrate anionic complex. The adsorption process exhibited pseudo-second-order kinetic behavior and adhered to the Langmuir isothermal adsorption model. The maximum adsorption capacity of D201 × 7 resin for Ge was 214 mg g−1. Selective Ge uptake and purification could proceed by column separation The results showed that enrichment factor was 74.7, and the desorption concentration of Ge was increased from 500 mg L−1 to 36.6 g L−1. The D201 × 7 resin exhibited high selectivity, excellent adsorption performance and good stability, making it a viable candidate in industrial applications.

Morphological control of electrodeposited iron for fluctuating photovoltaic electrical energy

With the Paris Agreement, the installed capacity of green power, such as photovoltaic (PV) and wind power, is growing rapidly at a rate of more than 10 % per year. The practical application of these green electrical energies is limited by the relative lag in the scale of energy storage systems. In response to the pressure on energy storage systems, we explored the feasibility of supplying DC power directly from a PV plant to an industrial electrolyzer by comparing the electrodeposition behavior of Fe2+ in a sulfuric acid system from stabilized DC and fluctuating PV power sources. We found that the factor that damages the stable operation of an iron electrodeposition system the most is the presence of hydrogen evolution reactions, where the generation of hydrogen bubbles reduces the current efficiency of the electrodeposition system and, in severe cases, destroys the surface morphology of the deposited products, causing devastating damage to the system. On this basis, we designed a simple scheme that uses heterogeneous bubble nucleation instead of homogeneous bubble nucleation for rapid bubble expulsion from the cathode surface. Benefiting from the rapid transfer of bubbles, the current efficiency of the electrodeposited iron system increases by 1.25%–10 % at different current densities, and the maximum roughness decreases by 129–2,396 nm, which considerably improves the stability of the electrodeposited iron system for PV power. This work provides useful experimental support for the transformation of the traditional steel smelting industry, which is characterized by high carbon emission and energy consumption, into an environmentally friendly industry.

Corrosion Behaviors’ Investigation of Carbide Coatings Developed for Sulphuric Acid Recovery Systems

In this study, corrosion resistance of cobalt and nickel, which are known to have high corrosion resistance, reinforced tungsten carbide coatings applied to low carbon stainless steel material surfaces to reduce corrosion-induced losses in sulphuric acid recovery systems were investigated. During the recovery of sulphuric acid, aggressive sulphur systems in the baths cause the metal surface to dissolve and therefore a high amount of material loss occurs. In order to minimize corrosion induced material loss, 316 L stainless steel surfaces were coated with an interlayer of 95% nickel and 5% aluminium alloy, and then tungsten carbide coatings were synthesized on the surfaces of substrate materials reinforced with 13% cobalt and 13% nickel, respectively by thermal spraying method to further reduce the corrosion rate. Characterization of the produced coatings were carried out by X-ray diffraction (XRD), scanning electron microscope (SEM), optical microscope, image analyzer, and surface roughness device. The standard potentiodynamic polarization characteristics of the coatings for 1M H2SO4 solution at room temperature were investigated with a potentiostat/galvanostat device. As the obtained results, nickel reinforced tungsten carbide coatings with nickel aluminium interlayer showed the highest corrosion resistance against sulfuric acid environment with 0,41 mm/year corrosion rate. As a result of the article, the corrosion resistance of 316L stainless steels in sulfuric acid systems was improved by 5.02 and 3.15 times, respectively.

Study on synergistic leaching of potassium and phosphorus from potassium feldspar and solid waste phosphogypsum via coupling reactions

To achieve the resource utilization of solid waste phosphogypsum (PG) and tackle the problem of utilizing potassium feldspar (PF), a coupled synergistic process between PG and PF is proposed in this paper. The study investigates the features of P and F in PG, and explores the decomposition of PF using hydrofluoric acid (HF) in the sulfuric acid system for K leaching and leaching of P and F in PG. The impact factors such as sulfuric acid concentration, reaction temperature, reaction time, material ratio (PG/PF), liquid–solid ratio, PF particle size, and PF calcination temperature on the leaching of P and K is systematically investigated in this paper. The results show that under optimal conditions, the leaching rate of K and P reach more than 93% and 96%, respectively. Kinetics study using shrinking core model (SCM) indicates two significant stages with internal diffusion predominantly controlling the leaching of K. The apparent activation energies of these two stages are 11.92 kJ·mol−1 and 11.55 kJ·mol−1, respectively.

Thermochemical and Ionic Speciation Modeling of the Aqueous Sulfuric Acid System Up to 6 Molal and 0–100 °C

Thermochemical and Ionic Speciation Modeling of the Aqueous Sulfuric Acid System Up to 6 Molal and 0–100 °C

Efficient zinc extraction with novel phenyl phosphate PTOPP in sulfuric acid system

Traditional acidic phosphate extractants (D2EHPA and HEH/EHP) exhibit poor extraction performance under high-acid conditions and require saponification pretreatment to maintain the pH stability of the aqueous phase during the solvent extraction. However, saponification pretreatment produces a large amount of saline wastewater, resulting in high treatment costs and difficulty of the industrial waste salts utilization. Thus, we synthesized an efficient p-tert-octyl phenyl phosphate (PTOPP) extractant suitable for a high-acid system based on phenyl substitution and carbon-chain design. The structure and content of the synthesized products were confirmed to be [(CH3)3CCH2C(CH3)2C6H4O]2P(O)OH (diphenyl phosphate, P10B4, 88.26%) and (CH3)3CCH2C(CH3)2C6H4OP(O)(OH)2 (monophenyl phosphate, DHP10B4, 10.68%) via HRMS, LCMS, and NMR characterization combined with potentiometric titration. After three-stage countercurrent extraction and two-stage countercurrent stripping, the zinc extraction efficiency of PTOPP reached 85%, and the zinc concentration of aqueous phase increased from 20 g/L to 66.53 g/L with a 3.3 enrichment multiple. In comparison, the enrichment multiples of D2EHPA and HEH/EHP under the same conditions were only 1.5 and 1.1, respectively. The zinc extraction mechanism with PTOPP was determined by the slope method and structural characterization of the extracted compound (PTOPP-Zn). During the zinc extraction process, the P-OH and P=O groups in PTOPP interacted with Zn2+ to form Zn–O bonds through proton exchange and coordination reactions, and the molecular formula of the extracted compound was ZnA2·HA. The novel PTOPP significantly improves the zinc extraction performance and achieves a remarkable enrichment effect without saponification pretreatment, thereby avoiding the consumption of NaOH and the discharge of Na2SO4 wastewater. It has promising applications in the fields of low-grade zinc mineral resource recovery and heavy-metal wastewater disposal.

Enhancement of Atmospheric Nucleation Precursors on Iodic Acid-Induced Nucleation: Predictive Model and Mechanism.

Iodic acid (IA) has recently been recognized as a key driver for new particle formation (NPF) in marine atmospheres. However, the knowledge of which atmospheric vapors can enhance IA-induced NPF remains limited. The unique halogen bond (XB)-forming capacity of IA makes it difficult to evaluate the enhancing potential (EP) of target compounds on IA-induced NPF based on widely studied sulfuric acid systems. Herein, we employed a three-step procedure to evaluate the EP of potential atmospheric nucleation precursors on IA-induced NPF. First, we evaluated the EP of 63 precursors by simulating the formation free energies (ΔG) of the IA-containing dimer clusters. Among all dimer clusters, 44 contained XBs, demonstrating that XBs are frequently formed. Based on the calculated ΔG values, a quantitative structure-activity relationship model was developed for evaluating the EP of other precursors. Second, amines and O/S-atom-containing acids were found to have high EP, with diethylamine (DEA) yielding the highest potential to enhance IA-induced nucleation by combining both the calculated ΔG and atmospheric concentration of considered 63 precursors. Finally, by studying larger (IA)1-3(DEA)1-3 clusters, we found that the IA-DEA system with merely 0.1 ppt (2.5×106 cm-3) DEA yields comparable nucleation rates to that of the IA-iodous acid system.

Постановка задачи и построение формализованной энергетически автономной технологической системы на примере сернокислотного производства

The article searches for ways to improve the energy technological effectiveness and environmental safety of the sulfuric acid system, identifies its functional subsystems for which the processes occurring in them and the possibility of their application under given conditions can be independently investigated.

Determination and Correlation of Vapor–Liquid Equilibria for the Nitric Acid + Water, Nitric Acid + Water + Phosphoric Acid, and Nitric Acid + Water + Phosphoric Acid + Sulfuric Acid System

The wet-process production of phosphoric acid by the nitric acid method is considered as a promising technology with great development prospects due to no production of the byproduct phosphogypsum. However, the traditional nitro-phosphate fertilizer producing process cannot separate nitrogen and phosphorus thoroughly, which limits its applications. The key to solving this problem is to remove nitric acid from the crude phosphoric acid product obtained in the nitric acid wet process by evaporation. Therefore, it is important to measure the vapor–liquid equilibrium (VLE) data of the nitric acid + water + phosphoric acid + sulfuric acid quaternary system under different pressures and concentrations. In this study, the VLE data of the following systems were measured at 10, 20, 40, 60, 80, and 97.4 kPa by the quasi-static ebulliometric method: (1) nitric acid + water; (2) nitric acid + water + phosphoric acid; and (3) nitric acid + water + phosphoric acid + sulfuric acid. The electrolyte non-random two-liquid parameters for the following pairs were correlated with the VLE data by using Aspen Plus as a tool: HNO3-H2O, H3PO4-H2O, HNO3-H3PO4, HNO3-H2SO4, H3PO4-H2SO4, H+[H2PO4]−-H+[NO3]−, H+[NO3]−-H+[HSO4]−, and H+[H2PO4]−-H+[HSO4]−. The obtained VLE data and interaction parameters can provide the basis for the nitric acid method of mother liquor denitrification in the subsequent industry.

Distribution behavior and deportation of arsenic in copper top-blown smelting process

In recent years, the impurity content in copper concentrate increases gradually with the consumption of high-grade copper ore. When the arsenic content in the raw materials increases, large amounts of arsenic enter the sulfuric acid system, resulting in large amounts of waste acid that put great pressure on production and environmental protection. Using the distribution characteristics of arsenic in each phase, the possibility of enriching arsenic in the form of stable arsenates in the slag was investigated to enrich arsenic in the form of stable arsenates in the slag. It is shown that increasing CaO content in slag at relatively low temperatures, controlling the slag type and changing the slag composition effectively improved the ability of the slag to absorb arsenic. Based on a theoretical analysis used to optimize the process parameters and determine a reasonable slag type, an oxygen-enriched top-blown smelting experiment was conducted with mixed copper concentrates. The mechanism of arsenic fixation in smelting slag at a smelting temperature of 1180 °C (1453 K) was investigated, and the results showed that the As content in slag was increased by 20∼50% and decreased by 10∼30% and 10∼20% in the dust and matte, respectively. Thus, arsenic is fixed in silicate in the form of stable arsenate, which can be an effective and safe treatment solution for copper smelting processes.

Ultrasonic enhanced hydrazine sulfate acid leaching of low-grade germanium dust

By studying the principle of ultrasonic-enhanced leaching and the mechanism of reductive acid leaching of valuable metals, a new method of ultrasonic-enhanced hydrazine sulfate leaching of Zn and Ge in zinc oxide dust in the sulfuric acid system has been proved to be very effective. The phase of Ge was determined by the segmented dissolution method, and it was found that insoluble Ge mainly existed in the form of GeS2 and tetragonal phase germanium dioxide. Comparing the solubility of GeS2 and GeS in a hot high-acid system, it was found that GeS was more easily dissolved. And Ge4+ is more prone to hydrolysis at high acid concentration, resulting in germanium precipitation again. In addition, the presence of more Fe3+ in the solution will increase the potential of the system and inhibit the leaching of zinc ferrate. Therefore, the reduction method is used to reduce Ge4+ and Fe3+ to Ge2+ and Fe2+, which can accelerate the dissolution of zinc ferrate and effectively avoid the low leaching rate of zinc and germanium caused by the hydrolytic precipitation of Fe3+ and Ge4+. The valence states of Fe and Ge in the leachate were analyzed by ICP and XPS, and it was found that they mainly existed in the leachate in the divalent form, which indicated that Fe3+ and Ge4+ had been successfully reduced to Fe2+ and Ge2+. Some black substances were formed in the leaching process. EPMA analysis showed that the material was the oxide of silicon and aluminum, and the number of black substances increased gradually with the passage of leaching time, which led to the decreased metal leaching rate. The leaching kinetics is used to study the mechanism of the leaching process. By comparing the fitting degree of multiple models, the final mixed controlled model is determined to control the whole leaching reaction. Therefore, it is finally determined that when the initial acidity of 140 g/L, the liquid–solid ratio of 7 mL/g, the dosage of the reducing agent is 1/3 of the molar mass of Fe in zinc oxide dust, and ultrasonic intensity of 300 W is used to leach for 60 min at 333 K, Zn and Ge have the best leaching efficiency and economic benefits, and the leaching rates are 96.56 % and 94.62 %, respectively. Compared with conventional leaching, the leaching rate of Zn is increased by 6 %, and that of Ge is increased by 11 %.