26 results about "Cerium sulfate" patented technology

The invention relates to the technical field of leather chemical industry and leather manufacturing, in particular to a tannin extract based on metal complex modification and a preparation method and application of the tannin extract based on metal complex modification. 15 to 25 parts of aluminum sulfate; 5-10 parts of lanthanum sulfate / cerium sulfate; 0.5-2 parts of sulfuric acid; 0.5 to 2 parts of citric acid; and 500 to 600 parts of water. The modified tannin extract which is light in color, good in dispersity and excellent in tanning property is prepared through the steps of oxidative degradation, chelating masking, metal synergistic complexing and the like. The method is simple in process, environmentally friendly, efficient and suitable for industrial production, and the problems that a traditional vegetable tanning agent is low in whiteness and poor in light resistance stability when applied to white leather, and traditional metal tanning leather is hard in hand feeling, insufficient in light resistance and the like are effectively solved.

The invention relates to an electrolyte additive, a zinc-nickel battery and a preparation method of the zinc-nickel battery. The zinc-nickel battery electrolyte comprises the following components in percentage by mass: 25%-45% of potassium hydroxide, 1%-4% of zinc oxide, 0.2%-5% of potassium nitrite, 0.2%-1% of cerous sulfate and the balance of water. According to the zinc-nickel battery electrolyte, the cycle life of the battery is greatly prolonged, the safety of the battery is greatly improved, gas production of the battery is effectively inhibited, the cycle stability is improved, corrosion of a negative electrode active material and a current collector is effectively slowed down, the self-discharge rate of the battery is reduced, the capacity retention rate of the battery is remarkably improved, and the service life of the battery is prolonged. The ion concentration and conductivity in the electrolyte are improved, the internal resistance of the battery is reduced, the high-current charge-discharge capacity of the battery is improved, the electrolyte is prevented from being dried up due to water evaporation in the long-term cycle process, and the long cycle life and stability of the battery are further guaranteed. The zinc-nickel battery electrolyte is simple in preparation process flow, and the commercialization difficulty and cost are reduced.

The application discloses a kind of biocompatibility elemental selenium nanotubes and preparation method thereof, belong to the field of nano elemental selenium synthesis, homogeneous mixture is obtained by mixing cerium sulfate solution, sodium hydroxide solution and selenium hydrazine dispersion liquid, the concentration of cerium sulfate solution is 2~4mmol / L, the concentration of selenium powder in selenium hydrazine dispersion liquid is 300~380mmol / L, to obtain mixed system, the mixed system is carried out hydrothermal reaction at 60~90 DEG C, to obtain reaction liquid, the product in reaction liquid is separated and dried, and the cell experiment result proves that biocompatibility elemental selenium nanotube is obtained.The application solves the lack of controllable and stable synthesis problem existing in the synthesis process of the prior art elemental selenium nanotube, and facilitates the application in the medical field as a drug carrier in the later period.

The invention provides an alkaline chemical polishing solution suitable for a high-Si-content aluminum alloy inner runner and a polishing method, and belongs to the technical field of metal material surface treatment. According to the method, an alkaline polishing solution composed of sodium hydroxide, sodium nitrate, thiourea, sodium silicate, sodium phosphate, sodium fluoride, ceric sulfate and an additive is adopted for conducting long-time chemical polishing on the high-silicon aluminum alloy at the room temperature, and dilute acid neutralization, acetic acid activation and sodium oxalate and sodium dodecyl benzene sulfonate composite cleaning solution are matched for ultrasonic dust removal. According to the technology, nitric oxide pollution generated by acid polishing is avoided, the corrosion rate is reduced, effective polishing of a complex inner runner is achieved, the surface roughness is remarkably reduced, material loss is small, hanging dust is completely removed, and the technology has environment friendliness and high-precision machining capacity.

An electrochemically mediated, hydrometallurgical method is provided for extraction of nickel, zinc, lead, silver, molybdenum, and / or copper from sulfide minerals. These metal concentrates, such as pentlandite, pyrrhotite, pyrite, sphalerite, galena, Ag2S, MoS2, etc., are contacted with nitric acid and cerium(IV) nitrates, cerium(IV) methanesulfonate, and / or cerium(IV) sulfate, as oxidative leaching agents to preferentially leach the target metals contained therein. The strong oxidizing capacity of cerium(IV) enables rapid dissolution of metal sulfides under ambient conditions. Cerium(IV) can be electrochemically regenerated and recycled for treatment of additional sulfide minerals. Target metal products can be extracted via processes such as solvent extraction and precipitation, enabling complete recovery, e.g., of nickel from pentlandite.

The invention discloses a cerium-manganese catalyst for low-temperature propane catalytic combustion as well as a preparation method and application of the cerium-manganese catalyst. According to the method, a continuous method is utilized under stirring, ammonium oxalate is used as a precipitator, manganese sulfate is used as a main catalytic active component, cerium sulfate is used as a trace auxiliary agent, and the invention aims at providing a stable and efficient preparation method of the cerium-manganese catalyst and realizing efficient degradation of propane catalytic combustion under a low-temperature condition. The technical scheme is as follows: (1) preparing a mixed solution A of manganese sulfate and cerous sulfate; (2) preparing an ammonium oxalate aqueous solution B; (3) uniformly stirring the uniform solution at normal temperature for 15 minutes; (4) respectively pumping the solution A and the solution B into a peristaltic pump A and a peristaltic pump B, and mixing and outputting along with a pipeline; (5) centrifuging, washing with deionized water and alcohol, and drying at 60 DEG C to obtain a solid product; and (6) further calcining the solid product in a muffle furnace to obtain a finished product. Relates to the technical fields of petrochemical engineering, thermocatalytic materials and environmental protection.

The invention belongs to the technical field of lead-acid storage batteries, and particularly relates to a high-temperature-resistant lead-acid storage battery positive plate and a preparation method thereof.The high-temperature-resistant lead-acid storage battery positive plate comprises lead paste A and lead paste B. The weight ratio of the lead paste A to the lead paste B is 1: 5, and the lead paste A comprises, by weight, 0.5-0.6% of cerous sulfate, 0.5-0.6% of antimony trioxide, 7-8% of dilute sulphuric acid, 7.8-9.5% of pure water and the balance lead powder; the lead paste B is prepared from the following components in percentage by weight: 0.20 to 0.27 percent of graphite, 0.08 to 0.12 percent of activated carbon fiber, 0.08 to 0.12 percent of 4BS power seed, 2.5 to 3.0 percent of red lead, 7 to 8 percent of dilute sulphuric acid, 8.5 to 9.5 percent of pure water and the balance of lead powder. The industrial pain point that the service life of the lead-acid storage battery is sharply shortened in a high-temperature area (such as a tropical area) and a high-temperature working condition (such as a communication base station and new energy equipment) is solved, the battery replacement frequency can be reduced, the use cost of a user can be reduced, the cooling energy consumption of an air conditioner (such as the communication base station) can be reduced, and the application scene of the lead-acid storage battery is expanded.

This invention belongs to the field of biomimetic nanomaterials technology, specifically providing a method for synthesizing biomimetic nanoenzymes and their application in antibacterial, anti-mold, and preservation of fruits and vegetables. The synthesis of the biomimetic nanoenzyme includes the following steps: (1) adding glutamic acid to deionized water and heating and stirring until a transparent or homogeneous glutamic acid solution is formed; (2) adding zinc sulfate and cerium sulfate to deionized water and ultrasonically dispersing them uniformly to obtain a bimetallic salt solution; (3) adding the bimetallic salt solution to the glutamic acid solution according to a molar ratio of zinc in zinc sulfate, cerium in cerium sulfate, and glutamic acid of 3~4:0.5~0.9:1, followed by the addition of an organic solvent, stirring under heating conditions, and then washing, drying, and grinding to obtain the biomimetic nanoenzyme. Experiments show that the biomimetic nanoenzyme Zn of this invention… 3.5 / Ce 0.9 -Glu has a bactericidal rate of 99.41% against Escherichia coli and 98.28% against Staphylococcus aureus, which can extend the storage period of cherry tomatoes to 12 days.

The invention discloses a synthesis method of methyl jasmonate, which comprises the following steps: preparing a catalyst from 1-butyl-3-methylimidazolium tetrafluoroborate, nano mesoporous silica and cerous sulfate according to the weight ratio of (10-15): (3-5): 1, and adding 2-(1-cyclopentenyl) methyl acetate, 1, 3-pentadiene and the catalyst according to the weight ratio of (6-10): (1.5-2.5): 1 into a reactor; removing oxygen in the reactor; reacting for 4 to 6 hours under the conditions that the temperature is 30 to 40 DEG C and the speed is 200 to 300r / min, so as to obtain a methyl jasmonate crude product; centrifuging the methyl jasmonate crude product to obtain supernate; extracting the supernate with an inorganic salt aqueous solution, and standing to obtain an organic phase; distilling the organic phase, and collecting fractions at 120-130 DEG C to obtain a methyl jasmonate primary product; and crystallizing and drying the jasmonic acid methyl ester primary product by using absolute ethyl alcohol to obtain a jasmonic acid methyl ester finished product.

The application discloses a method for preparing high-performance rare earth polishing powder from lanthanum cerium sulfate, and belongs to the technical field of rare earth polishing powder preparation. The method mainly comprises the following steps: precipitating lanthanum cerium sulfate solution and magnesium bicarbonate solution in a parallel flow feeding mode. The precipitated product is aged, washed, once separated from liquid, beaten, fluorinated, twice separated from liquid, dried at low temperature, calcined at high temperature, and broken and classified by air flow milling, so that a rare earth polishing powder product with good polishing and etching capacity is successfully prepared. The application selects lanthanum cerium sulfate as the original liquid, has a short separation process, low transformation cost, and is easy to popularize and promote in industrialization. The residual part of sulfate in the precipitated product can effectively adjust the hardness of the rare earth polishing powder particles and homogenize the morphology, so as to improve the cutting performance of the polishing powder. The magnesium salt wastewater and the fluorination wastewater generated in the application can be all reused to the production line for preparing the rare earth polishing powder, and zero wastewater discharge is realized in the whole process.

The invention discloses chemical copper deposition liquid for a chemical thick copper deposition process and a preparation method and application of the chemical copper deposition liquid. The chemical copper deposition liquid comprises the following components in mass concentration: 28-35 g / L of a complexing agent; 0.2-5 g / L of an additive; the concentration of copper ions is 3-3.5 g / L; 6-10 g / L of a reducing agent; the deionized water is metered by 1L; wherein the additive comprises 1, 10-phenanthroline, benzotriazole, guanosine, nickel ions, triethanolamine, N, N, N 'N'-tetra (2-hydroxypropyl) ethylenediamine and ceric sulfate, the chemical copper deposition liquid can achieve the deposition thickness of 18 microns or above within 2 hours by optimizing the selective matching of the complexing agent, the reducing agent and the like in the copper deposition composition and controlling the addition amount, the chemical copper deposition rate is larger than or equal to 8 microns / H, and the chemical copper deposition rate is larger than or equal to 8 microns / H. And the maximum copper thickness is greater than or equal to 20 microns.

This utility model discloses a continuous gradient addition device for extractant in a lanthanum-cerium separation process, comprising several tanks. Each tank has a feed pipe on its upper surface, a conduit connecting to adjacent tanks on its side surface, and a discharge pipe on the end of the tank's side surface. Centrifugal pumps are installed on both the discharge pipe and the conduit. A low-speed stirring device and a spraying device are also installed on the tanks. Multiple tanks are cascaded via conduits, and the flow rate between stages is dynamically controlled by the centrifugal pumps, causing the extractant concentration to decrease gradually, eliminating concentration jumps, and improving the lanthanum-cerium separation coefficient. The low-speed stirring device inside the tank improves extraction efficiency while preventing blockage of the tank bottom and pipes due to easy crystallization of cerium sulfate, reducing the frequency of downtime cleaning and improving work efficiency. The spraying device enables online cleaning after shutdown, improving residual liquid discharge rate and preventing cross-contamination between batches.

The present application relates to a kind of new magnetic composite coagulant, by the following preparation method is obtained, (1), the preparation of polymeric ferric phosphate sulfate:98% concentrated sulfuric acid is added dropwise to saturated hydrated ferric nitrate solution, then the prepared saturated Na2HPO4 solution and saturated NaHCO3 solution are added dropwise in turn, to obtain polymeric ferric phosphate sulfate;(2), the preparation of modified polymeric ferric phosphate sulfate: first silane coupling agent KH550 or KH570 is hydrolyzed 1 hour, then the hydrolyzed silane coupling agent KH550 is added dropwise into three-necked flask in step (1), to obtain modified polymeric ferric phosphate sulfate;(3), chitosan, Fe3O4 and modified polymeric ferric phosphate sulfate are dissolved in dilute acetic acid solution, slowly add cerium sulfate, react 2-6h to obtain new magnetic composite coagulant.Composite magnetic flocculant has the performance of realizing oil-water-floc separation quickly and efficiently.

The invention relates to a chemical thick copper deposition process and application thereof. A chemical copper deposition treatment method comprises the following steps: providing a copper-free substrate; carrying out roughening treatment; carrying out presoaking treatment; activating treatment; acceleration processing; chemical copper deposition treatment; wherein in the roughening treatment, a roughening solution is adopted to carry out roughening treatment on the surface of the substrate, and the roughening solution comprises the following components with the following concentrations: 50-400 g / L of chromic anhydride, 20-400 ml / L of concentrated sulfuric acid and 0.5-20 g / L of ceric sulfate; thus, the stepped treatment process can significantly improve the binding force between the electroless plating copper and the base material, the copper layer is not prone to falling off, the density of the catalyst layer is improved, the deposition rate of the electroless plating copper is increased, and the thickness of the electroless plating copper is increased. Particularly, a chromic anhydride / ceric sulfate composite coarsening system is innovatively adopted, so that the controllable roughness of 0.3-0.8 mu m is formed on the surface of the substrate, and the binding force is remarkably improved.

This invention relates to the field of aluminum plate surface treatment technology, specifically to a high-hardness, corrosion-resistant curtain wall aluminum plate and its preparation method, comprising the following processes: S1. Anodizing: Anodizing an aluminum plate in an electrolyte solution; the electrolyte solution includes sulfuric acid, boric acid, cerium sulfate, and polymethyl methacrylate; S2. Sealing treatment: Sealing the aluminum plate in a sealing solution under negative pressure; S3. Encapsulation treatment: Immersing the aluminum plate in a sealing solution to obtain the curtain wall aluminum plate. This invention uses sulfuric acid, boric acid, cerium sulfate, and polymethyl methacrylate as electrolyte components for anodizing, reducing the solubility of the oxide film, alleviating corrosion at defects in the aluminum plate, allowing aluminum ions to accumulate on the aluminum plate surface, attracting anions, reducing reaction resistance, inhibiting the large-scale generation of oxygen, and generating a high-thickness oxide film on the aluminum plate surface. This improves the uniformity and density of the oxide film, enhancing its corrosion resistance, wear resistance, and microhardness, thus improving the hardness and corrosion resistance of the resulting curtain wall aluminum plate.

This invention relates to the preparation of lithium iron phosphate nanospheres. First, an FePO4 precursor is prepared using an iron and phosphorus source. Then, cerium sulfate and europium sulfate are added to Li3PO4 in a 1:1 doping ratio to prepare modified Li3PO4. Furthermore, a cationic surfactant, octadecyl dimethyl benzyl ammonium chloride, is added during the reaction of the FePO4 precursor and the modified Li3PO4. This invention utilizes modified Li3PO4 and the addition of the cationic surfactant octadecyl dimethyl benzyl ammonium chloride to achieve a better spherical shape in lithium iron phosphate. The addition of the surfactant has a significant impact on the particle size and morphology of iron phosphate, reducing particle aggregation and controlling particle growth. Modification of Li3PO4 with cerium sulfate and europium sulfate alters the interatomic spacing and positions within the crystal, causing cell shrinkage and changing the internal structure of the crystal, thus affecting the external morphology of iron phosphate. Doping with metal ions effectively increases the tap density of the material, thereby improving the volumetric capacity and cycle performance of lithium iron phosphate.

The invention belongs to the technical field of electrolytic copper foils, and provides a low-profile electrolytic copper foil and application thereof. The low-profile electrolytic copper foil sequentially comprises a crude foil layer, a roughening treatment layer and a passivation barrier layer, and is prepared according to the following method: (1) preparing the crude foil layer: adding tris (2-hydroxyethyl) methylammonium hydroxide and dimethoxyhydroquinone into an acidic copper sulfate electrolyte, and electrolyzing to obtain a crude foil; (2) roughening treatment of the crude foil: adding the crude foil into a roughening treatment solution containing cerous sulfate and organic acid for electrolytic roughening treatment; and (3) preparing a passivation barrier layer: adding the roughened copper foil into a passivation treatment solution for electrolytic passivation to obtain the passivation barrier layer. The prepared electrolytic copper foil is lower in flatness and profile tolerance when the thickness is lower, and meanwhile, the electrolytic copper foil has better tensile property and stripping property and is excellent in comprehensive performance.

The application relates to a lithium iron phosphate positive electrode material for a long-cycle lithium battery and a preparation method thereof, and belongs to the technical field of lithium ion battery materials. The positive electrode material comprises lithium carbonate, diiron trioxide, ammonium dihydrogen phosphate, ammonium carbamate, polyethylene glycol 2000, cerous sulfate and superconducting carbon black, and can further add hydroxyl-modified diatomite, lanthanum-cerium sulfate composite salt, sodium dioctyl sulfosuccinate and gelatin-coated ammonium bicarbonate microcapsules as auxiliary components. By introducing a three-component synergistic pore-forming system, combining a temperature programming and alkaline regulation strategy, a lithium iron phosphate positive electrode material with a high specific surface area, excellent pore size connectivity and stable structure is constructed.

The application relates to an antioxidant broad-spectrum sunscreen film and a preparation method thereof and relates to the technical field of biological materials. TiO2 and a dispersing agent are added into water, and the pH is adjusted to be alkaline; a cerium sulfate solution is added, then heating is carried out, CeO2 is obtained by hydrolysis of the cerium sulfate, and the CeO2 is deposited on the surface of the TiO2, TiO2@CeO2 nanoparticles are obtained; the TiO2@CeO2 nanoparticles, the dispersing agent and dopamine hydrochloride are added into water, the pH is adjusted to be alkaline, then heating is carried out, the dopamine is coated on the surface of the CeO2, and TiO2@CeO2@PDA nanoparticles are obtained; the TiO2@CeO2@PDA nanoparticles, polydimethylsiloxane, fumed silica, water, an emulsifying agent, a thickening agent, a preservative, hydroxyethyl cellulose and a catalyst are added into water, uniform mixing is carried out, vacuum is drawn, and an antioxidant broad-spectrum sunscreen film is obtained. The sunscreen film prepared by the application has strong antioxidant property, good biocompatibility and a broad-spectrum sunscreen effect.

The invention discloses a preparation method of an SCR (Selective Catalytic Reduction) denitration catalyst applicable to treatment of alkaline earth metal-containing flue gas in cement kiln tail. The preparation method comprises the following steps: mixing, heating and stirring ethanol and butyl titanate to form a solution A; mixing, heating and stirring ethyl silicate, ethanol, acetic acid and deionized water to form a solution B; adding the solution B and the citric acid solution into the solution A, uniformly stirring to form viscous gel, standing, drying, roasting and screening to obtain a catalyst carrier TiO2-SiO2; the preparation method comprises the following steps: dissolving cerium sulfate tetrahydrate in deionized water, adding a catalyst carrier TiO2-SiO2, standing, drying, roasting and screening to obtain Ce (SO4) 2 / TiO2-SiO2; the preparation method comprises the following steps: dissolving ammonium metavanadate, oxalic acid and ammonium tungstate in deionized water, adding Ce (SO4) 2 / TiO2-SiO2 to obtain a mixed solution, dissolving Co (NO3) 2 / Sb (CH3COO) 3 in the mixed solution, fully stirring, drying, roasting and screening to obtain the denitration catalyst. The prepared catalyst can effectively remove high-concentration alkaline earth metal dust rich in cement kiln tail flue gas, and the tolerance to CaO, CaCO3 and CaSO4 is improved.

A preparation method of a self-heating bifunctional catalyst for decomposing nitrogen oxides belongs to the field of decomposition of nitrogen oxides in gases, and comprises the following steps: taking ferric sulfate, manganese sulfate, cerous sulfate, praseodymium sulfate and titanium sulfate as raw materials, dissolving the raw materials in an alcoholic solution, then adding citric acid into a beaker, continuously stirring until the citric acid is dissolved, then adding ammonia water to adjust the pH value, and stirring to obtain a mixed solution; and finally, adding polyacrylamide, continuously stirring, filtering, and roasting a filter cake in a mixed atmosphere of oxygen and argon to obtain a final product. In the nitrogen oxide decomposition process, the product has a self-heating function, the gas temperature can be increased to 150-180 DEG C from 50-80 DEG C, and the decomposition rate of nitrogen oxide is larger than 99%. According to the invention, the consumption of energy and ammonia gas in the decomposition process of nitrogen oxides can be reduced, carbon monoxide contained in sintering flue gas can be utilized, the use cost can be reduced, and the emission of CO can be reduced.

The invention relates to a novel magnetic composite coagulant, which is prepared by the following preparation method: (1) preparation of polymeric ferric phosphate sulfate: dropwise adding 98% concentrated sulfuric acid into a saturated ferric nitrate hydrate solution, and then sequentially dropwise adding a prepared saturated Na2HPO4 solution and a saturated NaHCO3 solution to obtain polymeric ferric phosphate sulfate; (2) preparation of modified polymeric ferric phosphate sulfate: firstly hydrolyzing a silane coupling agent KH550 or KH570 for 1 hour, and then dropwise adding the hydrolyzed silane coupling agent KH550 into the three-necked flask in the step (1) to obtain the modified polymeric ferric phosphate sulfate; and (3) dissolving chitosan, Fe3O4 and the modified polymeric ferric phosphate sulfate in a dilute acetic acid solution, slowly adding cerous sulfate, and reacting for 2-6 hours to obtain the novel magnetic composite coagulant. The composite magnetic flocculant has the performance of quickly and efficiently realizing oil-water-floc separation.

The invention discloses a biocompatible elemental selenium nanotube and a preparation method thereof, and belongs to the field of nano elemental selenium synthesizing.The preparation method comprises the steps that a ceric sulfate solution, a sodium hydroxide solution and a hydrazine hydrate dispersion liquid of selenium are evenly mixed, the concentration of the ceric sulfate solution is 2-4 mmol / L, the concentration of selenium powder in the hydrazine hydrate dispersion liquid of selenium is 300-380 mmol / L, and a mixed system is obtained; the mixed system is subjected to a hydrothermal reaction at the temperature of 60-90 DEG C, a reaction solution is obtained, products in the reaction solution are separated and then dried, and cell experiment results prove that the biocompatible elemental selenium nanotube is obtained. The invention solves the problem of lack of controllable and stable synthesis in the existing elemental selenium nanotube synthesis process, and is convenient to be applied to the medical field as a drug carrier in the later period.

The invention belongs to the technical field of lead-acid storage batteries, and particularly relates to a nanometer repairing liquid used in a high-temperature area and a preparation method and application of the nanometer repairing liquid in the lead-acid storage battery, and the nanometer repairing liquid comprises the following components in percentage by weight: 0.005-0.01% of cerous sulfate, 0.003-0.007% of perfluorooctane sulfonic acid, 0.05-0.1% of nanometer aluminum oxide, 0.05-0.1% of nanometer silicon dioxide, 8-10% of deuterium water, 0.7-0.9% of anhydrous sodium sulfate, 32.5-33% of concentrated sulfuric acid and the balance of water. And the balance of pure water. According to the invention, the performance degradation of the lead-acid storage battery in a high-temperature environment is obviously slowed down, the problem that the service life of the battery is sharply shortened in the high-temperature environment is directly solved, and the battery replacement frequency and cost of a user are reduced; and meanwhile, the problems of water evaporation, electrolyte layering, heat dissipation capability, heat stability and polar plate vulcanization and corrosion of the lead-acid storage battery in a high-temperature environment are systematically solved, the battery repair effect is remarkably improved, and the cycle index of the lead-acid storage battery is prolonged.

The invention provides a modified ardealite soil conditioner and a preparation method thereof, the soil conditioner comprises the following components by mass: 100 parts of ardealite, 2-10 parts of modified incineration waste, and 1-5 parts of lanthanum cerium sulfate; the modified incineration waste is obtained by calcining rice husks or straws and a nitrogen-containing compound. Ardealite and the modified incineration waste are mixed and stirred, then lanthanum-cerium sulfate is sprayed, stirring and mixing are continued, and the modified ardealite soil conditioner is obtained after aging. The soil conditioner provided by the invention is simple in preparation process and low in cost, and also can realize high-value utilization of phosphogypsum.

The present application relates to a kind of preparation methods of rare earth slow-release fertilizer for alfalfa.The method is to add the mixture of concentrated sulfuric acid and concentrated nitric acid to active carbon and carry out hydrophilic treatment;The active carbon treated is respectively subjected to humic acid adsorption treatment and lanthanum sulfate+cerium sulfate soaking treatment;The active carbon adsorbed humic acid is mixed with the active carbon adsorbed rare earth sulfate uniformly, and rare earth slow-release fertilizer is obtained.The present application slowly releases humic acid and rare earth sulfate by active carbon, and slowly ionizes rare earth ion, realizes the purpose of slowly releasing soluble rare earth-humic acid complex, and guarantees the efficiency and long-acting of rare earth fertilizer.The present application is simple in operation, low in product cost, and can obtain efficient rare earth slow-release fertilizer for the quality improvement and yield increase of alfalfa, with significant industrialization advantage.