Low Acid Consumption Research Articles

Process optimization and economic estimation of nitric acid dissolution for recycling waste wind blades

With the widespread retirement of wind turbines, many discarded waste wind blades have been generated, and how to handle them efficiently has become a critical issue. This study investigated the dissolution of discarded waste wind blades with nitric acid (HNO3) by varying acid concentration, reaction time, temperature, and HNO3 volume. Based on a series of single-factor experiments, the optimal conditions for low energy and acid consumption were determined, and the separation rate of resin reached 95%. As the cost-benefit analysis results suggested, an economic method to recycle a variety of high-value products was achieved. Furthermore, the implementation of a continuous chemical decomposition strategy for multi-batch processing significantly minimized acid consumption, resulting in a further reduction in recycling costs. This work provided an economically and technologically feasible way for recycling materials from decommissioned wind turbines, in order to answer the challenge of emerging solid waste management.

Closed-loop cleaning treatment system — resource recovery of coal gangue

ABSTRACT Coal gangue (CG) is one of the main solid wastes emitted by coal mining. It causes severe damage to the environment. CG contains high levels of valuable elements (Al, Si) and has the potential for utilization and clean disposal. Here, an environment-friendly process for separating valuable components from CG was proposed: the closed-loop system of activation-leach-separation. The results show that the decarbonization rate was close to 100% under the optimum conditions of CG particle size of 0.075 mm to 0.15 mm and activated at 800°C for 120 min. Subsequently, it was transformed into a mixed-acid system with a hydrochloric acid (HCl) concentration of 4.5 mol/L, hydrofluoric acid (HF) volume fraction of 15%, and the liquid-solid ratio of 10:1, which achieved excellent separation efficiency. The residual rate of Al in the solution was only 0.7%, and the extraction rate of Si can reach 71.6%. Further, industrial-grade AlF3 products were also recovered. By adding saturated KCl solution and reacting at 33°C for 15 min, Si was further recovered in K2SiF6, and the yield was 85.83%. Particularly, the leaching solution maintained good extraction efficiency in the subsequent three cycles, the yield of K2SiF6 was 88.29%, confirming the feasibility of the closed-loop system. This treatment embodied the environmental-friendly properties of low acid consumption and low effluent discharge, providing a feasible method for clean treatment and resource utilization of CG.

Efficient production of xylooligosaccharides from Camellia oleifera shells pretreated by pyruvic acid at lower temperature

XOS production from lignocellulose using organic carboxylic acids and alkyd acids has been widely reported. However, it still faces harsh challenges such as high energy consumption, high cost, and low purity. Pyruvic acid (PYA), a carbonyl acid with carbonyl and carboxyl groups, was used to produce XOS due to its stronger catalytic activity. In this work, XOS was efficiently prepared from COS in an autoclave under the condition of 0.21 M PYA-121 °C-35 min. The total yield of XOS reached 68.72 % without producing any toxic by-products, including furfural (FF) and 5-hydroxymethylfurfural (5-HMF). The yield of xylobiose (X2), xylotriose (X3), xylotetraose (X4), and xylopentaose (X5) were 20.58 %, 12.47 %, 15.74 %, and 10.05 %, respectively. Meanwhile, 89.05 % of lignin was retained in the solid residue, which provides a crucial functional group for synthesizing layered carbon materials (SRG-a). It achieves excellent electromagnetic shielding (EMS) performance through graphitization, reaching −30 dB at a thickness of 2.0 mm. The use of a PYA catalyst in the production of XOS has proven to be an efficient method due to lower temperature, lower acid consumption, and straightforward operation.

Selective and efficient extraction of lithium from spodumene via nitric acid pressure leaching

The thriving electric vehicle market has fueled a remarkable surge in the demand for lithium. Consequently, a heightened emphasis has emerged on the extraction of lithium from spodumene deposits. However, the sustainable growth of the lithium industry encounters challenges. The traditional process has the disadvantages of high acid consumption, high extraction rate of impurities and difficult purification of leach liquor. To address these challenges, this study proposes a process for the selective and efficient extraction of lithium from spodumene via nitric acid pressure leaching. In an autoclave at 200 °C, initial nitric acid concentration of 1 mol/L, liquid-to-solid ratio of 2.5 mL/g, and holding time of 30 min, 95 % Li was extracted, with low extraction rate of impurity elements. During pressure leaching, the aluminum–silicate cage structure of β-spodumene remains intact, while H+ freely exchanges with Li+ within the structure, resulting in the formation of HAlSi2O6. Subsequently, the leach liquor underwent thermal decomposition at 250 °C to achieve lithium-aluminum separation. It's noteworthy that nitric acid can be recycled in the process, resulting in low acid consumption. The proposed process has the potential to contribute significantly to the lithium industry by facilitating the adoption of environmentally friendly and sustainable practices.

Single reaction chamber microwave digestion coupled with ICP-MS for the determination of ultra-trace mercury in rocks.

In this study, a method for rock digestion using a single reaction chamber (SRC) microwave system was established. Nitric acid (HNO3) and hydrofluoric acid (HF) were used as digestion agents, and the determination of mercury (Hg) in rocks was performed by inductively coupled plasma mass spectrometry (ICP-MS). The optimal conditions for the SRC microwave system were achieved at 260 °C and 70 bar, with a mixture of 3 mL of 65-68 wt% HNO3 and 1 mL of 49 wt% HF when the sample weight is in the range of 0.025-0.05 g. The method quantitation limit (MQL) was determined to be 0.0016 mg kg-1. Measurement accuracy was evaluated using five Chinese nationally certified reference materials, demonstrating good consistency between measurement results and certified values. The method was applied to two rock samples, resulting in a recovery rate ranging from 105% to 109%. This method exhibits high sensitivity, stability, and low acid consumption. Importantly, it provides a reliable and efficient determination method for Hg in rocks, which is of great significance in geochemical analysis.

The development and validation of a new method for the fast determination of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn in rice by inductively coupled plasma optical emission spectrometry.

An alternative method of rice sample preparation for measuring the total content of selected elements, i.e., Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn, by ICP OES was developed. The proposed approach is based on the ultrasound-assisted extraction (USAE) of rice samples in the presence of a small amount of concentrated HNO3. The optimal operating parameters were found using the design of experiments (DOE) approach, and the studied experimental factors were the temperature of the ultrasonic bath (A), the sonication time (B), and the volume of concentrated HNO3 added per 0.5 g of a rice sample (C). Under the optimal conditions of the USAE procedure, i.e., A = 60 °C, B = 16 min and C = 4.0 mL, the rice samples were readily solubilized, and the obtained sample solutions could be analyzed by ICP OES with the simple standard solution calibration (without matrix matching). The analysis of the certified reference material (rice flour, NIST SRM 1568b) confirmed the satisfactory trueness of the USAE-ICP OES method. Additionally, no statistically significant differences between the results obtained for the samples prepared by USAE and open-vessel wet digestion (WD, the reference method) were found. In comparison to the routinely used microwave-assisted digestion and open-vessel digestion, the USAE approach offers lower acid consumption, lower detection limits (LODs) of elements, ranging from 4.0 ng g-1 for Mn to 2.7 µg g-1 for K, and a much shorter time of sample preparation.

Selective Separation and Recovery of Li from Spent LiFePO4 Cathode Materials by Oxidation Roasting Followed by Low-Acid Pressure Leaching

The environmental and economic benefits of recycling spent LiFePO4 batteries are becoming increasingly important. Nevertheless, the reprocessing of this type of material by conventional processes remains a challenge due to the difficulties of Li and Fe separation and low product purity. Herein, a new approach for recovering Li to separate iron and phosphorus from spent LiFePO4 cathode materials is developed. Selective separation of Li can be achieved by oxidation roasting followed by low-acid pressure leaching. During the oxidation-roasting stage, almost all the stable LiFePO4 cathode materials were first transformed into Li3Fe2(PO4)3 and Fe2O3, with the most suitable oxidation-roasting temperature determined to be 550 °C. Then, >96% of Li could be extracted using 0.5 mol·L−1 H2SO4 with an L/S ratio of 150 g·L−1 at 110 °C for 1 h; in contrast, the leaching of Fe was 0.03%. The mineral-phase composition of the leaching residues mainly includes FePO4·2H2O, Fe2O3, and C, which can be used as a raw material for preparing battery-grade FePO4. These findings demonstrate that the recycling process has the advantages of high selectivity for Li, excellent reaction kinetics, low acid consumption, and free oxidizing agent that may benefit the development of a circular economy.

Assessing the impact of oil saturation on wormhole morphology in carbonate acidizing

Carbonate acidizing is a well stimulation technique used to improve oil production by acid injection into the formation, creating conductive paths through rock dissolution. Most of the acidizing laboratory experiments are conducted on water-saturated rocks, assuming no oil is present after previous drilling and completion operations. However, different saturation conditions can occur in the rock formation, affecting the acidizing process. This study aims to assess the impact of oil saturation on carbonate acidizing. Reactive flow experiments were conducted on rocks saturated with water and oil using HCl 0.5 M and HCl 15%wt. at room temperature and 45 °C at flow rates of 1 and 20 mL/min. X-ray microtomography was used to visualize the wormhole morphology and compare the pore-volume-to-breakthrough (PVBT) values for each flow condition. Oil saturation resulted in efficient propagation of the wormhole with lower acid consumption and lower PVBT values. At 45 °C, PVBT values decreased by 54% for HCl 15%wt. at 20 mL/min. Wormhole morphology showed a smaller thickness in its propagation with oil saturation than with water saturation at the lower acid concentration, but not at the higher concentration. The presented results contribute to a deeper understanding of the significance of oil saturation in reactive flow during carbonate acidizing.

IRON REMOVAL FROM LADEN BIOLEACHING SOLUTION BY PROCESSES OF SOLVENT EXTRACTION AND MAGNETITE SYNTHESIS

Laden leach solution, generated from bioleaching of pyrometallurgical copper slags with a mixed culture of moderately thermophilic bacteria in a bioreactor, contains several base metals (Cu, Co, Zn) and a very high concentration of iron (33,9 g/ L). Further processing of cobalt and zinc to the respective final products requires preparatory iron removal from the laden leach solution. The direct iron removal from that solution as goethite was unacceptable because of the significant co-precipitation of copper and cobalt from the solution. The main aim of this paper is to study magnetite (Fe3O4) synthesis as an approach for iron removal to a value-added product as a step of the processing of a laden solution generated due to the bioleaching of non-ferrous metals in a bioreactor. Ferrous iron oxidation to ferric state was efficient when the addition of H2O2 (30 %) was combined with maintaining the pH 3,1-3,3 with NaOH and air purging. Solvent extraction with 25 % D2EHPA and 7,5 % TBP dissolved in kerosene efficiently separated the dissolved iron and the base metals from the processed solution. However, in the presence of H2, the iron was stripped from the organic solvent with low acid consumption. The applied precise control of the chemical precipitation and oxidation processes at 50 degrees Celsius allowed the iron content (11,7 g/ L) in the stripping solution to be removed efficiently as magnetite (Fe3O4). Based on the chemical content of iron, copper and sulphur, the synthesised nanoparticles of magnetite could be applicable in many sectors (steel, chemical, and electronics).

Selective separation Al3+/Gd3+ by designed carboxylic acid-ionic liquid with low acid and alkali consumption

As the associated element of ion-adsorbed type rare earth ores, aluminum ion (Al3+) has a great influence on the purification of gadolinium ion (Gd3+). In this paper, six carboxylic ionic liquids were synthesized with methyltrioctylammonium ([N1888]+) as cation and carboxyl group as anion, and optimized for selective separation of Al3+/Gd3+. The extraction capability, separation factor, stripping property and recycling stability of the ionic liquid on the separation of Al3+ and Gd3+ were systematically investigated. In addition, the loaded Al3+ can be totally stripped by 0.08 mol‧L−1 HCl solution. A particularly high separation factor of 923 can be obtained for removing Al3+ from industrial GdCl3 feed solution (762 mg‧L−1 Al3+ and 146 g‧L−1 Gd3+). The removal rate of Al3+ was up to 98.69% and the recovery rate of Gd3+ achieved at 92.47% by carboxylic ionic liquid ([N1888][C7H11O2]) in one-step extraction. After 0.6 mol‧L−1 HCl solution stripping and 0.5 mol‧L−1 NaOH solution regenerating, the extraction efficiency of Al3+ was only reduced by 3% after 5 cycles of organic phase. With the low acid and base concentration, it greatly reduced the chemical consumption and significantly the emission of high ammonia–nitrogen wastewater inindustry. This work provides a low-carbon process for efficient removal of Al3+ from industrial GdCl3 feed by carboxylic ionic liquids.

Electrochemical leaching of critical materials from lithium-ion batteries: A comparative life cycle assessment

The manufacturing of lithium-ion batteries (LIB) requires critical materials such as cobalt (Co) and lithium (Li) that are essential for clean-energy products including electric vehicles. Because of their rapidly increasing demand and limited supply, the recycle and reuse of these materials from end-of-life LIB have garnered a lot of interest. Electrochemical leaching has emerged as a sustainable method to extract critical materials out of LIB, so life cycle assessment was conducted to compare the environmental impacts with traditional peroxide-based leaching and another emerging technology – SO2-based leaching. The results showed that electrochemical leaching reduces the global warming potential (GWP) by 80%−87% compared to peroxide-based leaching due to a lower acid consumption, avoidance of hydrogen peroxide, and regeneration of reducing agent iron (II) sulfate and compares well with SO2-based leaching in most impact categories. The analysis suggested renewable energy can further reduce the environment footprint of electrochemical leaching.

Lithium recovery from pretreated α‐spodumene residue through acid leaching at ambient temperature

AbstractA novel alkaline hydrothermal approach for low‐temperature conversion of α‐spodumene into Li2SiO3 residue was proposed, providing a promising method for extracting lithium from α‐spodumene as a pretreatment process. This work proposed a systematic investigation for extracting lithium from the residue by acid leaching and preparing lithium carbonate. The reaction feasibility between Li2SiO3 and acids (HCl and H2SO4) was first evaluated through thermodynamic calculation. Compared with the leaching effects of hydrochloric acid and sulphuric acid, sulphuric acid is the preferred leaching agent due to its higher extraction efficiency for lithium and lower acid consumption. Lithium extraction efficiency from the residue achieved up to 87.48% under the following optimized conditions: 0.75 mol/L H2SO4, 0.4 times the theoretical amount of acid, 10 min, 30°C, and 100 rpm. Based on the optimized conditions, the lithium‐containing solution was concentrated through three consecutive cycles of leaching, which obtained a concentration of 17.78 g/L for lithium. The leaching solution was purified by CaO‐Na2CO3, resulting in the removal rates of SiO32−, Mg2+, and Ca2+ of 84.22%, 95.51%, and 90.55%, respectively. Finally, the solution was precipitated with sodium carbonate to prepare Li2CO3. This paper facilitates the development of an economical process for efficient lithium extraction from spodumene at low temperatures.

Effective leaching of spent lithium-ion batteries using DL-lactic acid as lixiviant and selective separation of metals through precipitation and solvent extraction.

Recycling cathodic materials from spent lithium-ion batteries (LIBs) is crucial not just for the environmental aspects but also for the supply of precious raw materials such as cobalt and lithium. As a result, developing a leaching process with low acid consumption, cost-effectiveness, low environmental impact, and high metal recovery is essential. In this article, the sustainable hydrometallurgical route for recovery of Li and Co from spent LIBs using DL-lactic acid as lixiviant is proposed. The different leaching parameters were studied to optimize the leaching conditions. With increasing lactic acid concentration from 0.1mol/L to 1.0mol/L, the leaching efficiency of Li and Co increased from 23% to 41% and 2% to 14%, respectively. The reductant H2O2 has a major role which reduced Co3+ to Co2+ and increasing the leaching efficiency of Co from 15.2% (1% H2O2) to 73.4% (6% H2O2). The maximum leaching efficiency of Li (99.8%) and Co (99%) was attained with 1.0mol/L lactic acid, 6% H2O2, 60°C, S/L ratio of 10g/L, and 60min leaching duration. The R2 values for the surface chemical reaction model were greater than 0.98, indicating that the lactic acid leaching process was controlled by the surface chemical reaction model. With 1.0mol/L 70% saponified Cyanex 272, a solvent extraction study showed a higher separation factor (βCo/Li) of 35.7 compared to other saponified and nonsaponified organophosphorus extractants. Using the precipitation method, 99.9% of Co and 99% of Li were precipitated as [Formula: see text] and [Formula: see text] with a purity of 99.4% and 98.3%, respectively.

New insight into oxidative roasting and leaching for NdFeB waste

NdFeB waste is an essential rare earth (RE) resource, which is the unique solid waste to realize large-scale RE recovery via HCl preferential dissolution method. However, the challenges of low oxidation efficiency and high acid consumption are seriously hindering RE efficient recovery. Herein, the mechanism between the phase structure transformation of roasting RE solid waste and RE elements' leaching behavior was first explored. The results showed the oxidation efficiency of NdFeB oil sludge (NOS) was improved from 2.5 % to 99.2 % with the temperature increasing. And a leaching model was proposed: Dense Layer Structure (≤400 ℃), Loose Layer Structure (400–600 ℃), and RE Insoluble Structure (≥600 ℃). The analysis of the leaching model indicates the dense oxide layer and the RE insoluble structure (RE insoluble NdFeO3 phase and particle adhesion) will affect the leaching efficiency of RE elements. Based on the oxidation efficiency, XPS, SEM, Raman, FTIR, and EDS-mapping analysis, an external oxide layer was verified on the microparticle of roasted NOS. Furthermore, the corresponding mechanism is discussed, and the improvement strategies are put forward. This study will supply a new insight into the theoretical basis for efficient and low HCl consumption recycling of NdFeB waste.

Research on Recovery of Valuable Metals from Cobalt-Rich Crust Using Carbon as a Reduction Agent during the Acid Baking Process

Cobalt-rich crust is a seabed metal mineral resource that is different from oceanic polymetallic nodules. Based on the higher Co content than polymetallic nodules, the commercial value of cobalt-rich crust may be better than that of polymetallic nodules. Due to the special distribution of valuable metals, commercial implementation is always limited. Herein, a novel process is proposed to efficiently and, in an eco-friendly way, recycle valuable metals from cobalt-rich crust. The results indicate that carbon could promote the decomposition of manganite in the cobalt-rich crust during the acid baking process, and the leaching ratio of Mn could increase by 50% when carbon is added during acid baking. In addition, it can be found that the promotion of carbon for Co is stronger at low sulfuric acid consumption than that at high sulfuric acid consumption; however, there is no promotion of carbon for leaching Ni and Cu during the acid baking process. The leaching ratio of Ni, Co, Cu, Mn, and Fe reached 98.59%, 91.62%, 93.81%, 41.27%, and 26.94%, respectively, when the mass ratio of the sulfuric acid and cobalt-rich crust was 0.567, the mass ratio of the carbon and cobalt-rich crust was 0.1, the temperature was 200 °C and the time was 240 min. This research could provide an alternative economic process for recycling valuable metals from cobalt-rich crusts.

A novel and greener sequential column leaching approach for the treatment of two different Greek laterites

Τhe present study investigates, from an environmental protection viewpoint, the efficiency of sequential column leaching of two different Greek laterites, i.e. a limonitic ore from central and a saprolitic ore from northern Greece. First, the most refractory limonitic laterite is leached in the first column for 15 days and the obtained pregnant leach solution (PLS) is further used for the leaching of the easier to treat saprolitic ore in the second column, thus achieving a significantly reduced acid consumption. The main parameters affecting the process efficiency, i.e. acid molarity (1.5 or 3 mol/L H2SO4) and addition of sodium sulfite (Na2SO3) in the leaching solution were studied. The extraction of Ni, Co, Fe, Al, Mg, Mn and Ca was determined by Atomic Absorption Spectroscopy (AAS), while the characterization of the ores and final residues was carried out by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA/DTA), and Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM-EDS) analysis. The results confirm the efficiency of the proposed green approach, which with the use of leaching solution containing 1.5 mol/L H2SO4 and 20 g/L Na2SO3 resulted in 73.8 % Ni, 71.6 % Co and 8.4 % Fe extraction after a short period of time (33 days), while the acid consumption, which is a serious environmental concern, was very low and did not exceed 300 kg/t ore. Overall, the proposed process not only improves the efficiency of leaching of different types of laterites for the recovery of both Ni and Co but also reduces the environmental impacts due to the significantly lower acid consumption.

Leaching Behavior of Scandium from Limonitic Laterite Ores Under Sulfation Roasting–Water Leaching

In the present study, the leaching behavior of scandium from limonitic laterites under sulfation roasting–water leaching (SAL) was explored. The mineralogical analysis of limonitic laterites showed that scandium was associated with the iron phase. The roasting temperature played an important role in the iron phase conversion during the sulfation roasting process. With an increase in the roasting temperature from 100 to 800 °C, the iron phase (goethite, magnetite, and hematite) gradually converted to monoclinic Fe2(SO4)3 (400 °C), then to rhombohedral Fe2(SO4)3 (600 °C), and finally to hematite (800 °C). Due to the iron phase conversion mechanism, the leaching efficiency of scandium gradually increased first and then decreased with the increase of roasting temperature from 100 to 800 °C. When limonitic laterites roasted at temperature of 600 °C for 2 h with sulfuric acid/laterite ratio of 1/4 (mL/g), a total of 81.15% of scandium and only 0.37% of iron were extracted into leaching solution at 30 °C with the liquid-to-solid ratio of 4:1 (mL/g) for 1 h with agitation. The SAL process enables the selective and efficient enrichment of scandium from low-grade limonitic laterites with lower costs for equipment and operation compared to high-pressure acid leaching (HPAL), lower acid consumption, and lower dissolution of iron compared to atmospheric pressure acid leaching (AL).

Bioleaching and Selective Precipitation for Metal Recovery from Basic Oxygen Furnace Slag

Decreasing ore grades and an increasing consumption of metals has led to a shortage of important primary raw materials. Therefore, the urban mining of different deposits and anthropogenic stocks is of increasing interest. Basic oxygen furnace (BOF) slag is produced in huge quantities with the so-called Linz-Donawitz process and contains up to 5.2, 0.9, 0.1, and 0.07% of Mn, Al, Cr, and V, respectively. In the present study, sulfur-oxidizing Acidithiobacillus thiooxidans and iron- and sulfur-oxidizing Acidithiobacillus ferridurans were applied in batch and stirred tank experiments to investigate the biological extraction of metals from BOF slag. In the batch experiments, up to 96.6, 52.8, 41.6, and 29.3% of Cr, Al, Mn, and V, respectively, were recovered. The stirred tank experiments, with increasing slag concentrations from 10 to 75 g/L, resulted in higher extraction efficiencies for A. ferridurans and lower acid consumption. Selective metal precipitation was performed at pH values ranging between 2.5 and 5.0 to study the recovery of Mn, Al, Cr, and V from the biolixiviant. Selective precipitation of V and Cr was achieved at pH 4.0 from A. thiooxidans biolixiviant, while Fe and V could be selectively recovered from A. ferridurans biolixiviant at pH 3.0. This work revealed the potential of BOF slag as an artificial ore for urban mining and demonstrated that combining bioleaching and selective precipitation is an effective method for sustainable metal recovery.

Efficient recovery of rare earth elements from discarded NdFeB magnets by mechanical activation coupled with acid leaching.

Due to the increasing demands and supply shortages for rare earth elements (REEs), the recovery of REEs from discarded NdFeB with high REE content has become extremely important. In this paper, a hydrometallurgical coupling process involving mechanical activation and selective acid leaching was proposed for the recovery of REEs from discarded NdFeB magnets. The effects of ball milling activation speed, hydrochloric acid concentration, and solid-liquid ratio on the leaching efficiencies of REEs in NdFeB magnets were studied. The results indicated that the ball milling activation method could enhance the reactivity of the samples through the action of mechanical force, which promoted the leaching efficiency and leaching speed of REEs. Under the optimum conditions (650-rpm activation speed, 0.4M hydrochloric acid, 100g/L solid-liquid ratio), the leaching efficiency of REEs increased up to 99% with low hydrochloric acid consumption and the leaching speed of REEs was triple than that of without activation. The final purity of recovered rare earth oxides reached up to 99.9%. All results demonstrated that ball milling activation coupled with selective leaching of hydrochloric acid could be an effective and environment-friendly strategy to achieve the recovery of REEs.

An innovative technique for the separation of ion-adsorption high yttrium rare earth ore by Er (III) / Tm (III) grouping first

The current separation technique of ion-adsorption high yttrium (Y) rare earth ore (high-yttrium ore) using 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) and naphthenic acid (NA) has been confronted with low separation efficiency and high acid consumption. This is a consequence of the low selectivity and the difficulty of complete stripping of heavy rare earths (HREEs). Therefore, an innovative separation technique of high-yttrium ore was proposed. The leachate of high-yttrium ore was firstly divided into Erbium (Er) / Thulium (Tm) groups with P507-isooctanol followed by separating Y (III) from the high Y-enrichment of Er (III) group with sec-octylphenoxy acetic acid (CA12)-tri-n-butyl phosphate (TBP). The basic thermodynamics experiments and cascade extraction simulations were conducted to verify the feasibility of this technology. The results show that P507-15vol% isooctanol is superior to P507 in both stripping ability and separation selectivity of HREEs. The first cascade extraction for Er (III) / Tm (III) grouping with P507-15vol% isooctanol was simulated successfully, reducing acid consumption but obtaining high purity products. In theory, the second cascade extraction simulation designed for separating Y (III) with CA12-TBP could not only improve the separation ability between Y (III) and light rare earths (LREEs) but also shorten the extraction stages and reduce the production costs. All these results revealed that this two-step separation process probably provided a promising application prospect for separating high-yttrium ore.