CN115305347A - Method for preparing zinc ferrite from neodymium iron boron waste - Google Patents
Method for preparing zinc ferrite from neodymium iron boron waste Download PDFInfo
- Publication number
- CN115305347A CN115305347A CN202211036080.7A CN202211036080A CN115305347A CN 115305347 A CN115305347 A CN 115305347A CN 202211036080 A CN202211036080 A CN 202211036080A CN 115305347 A CN115305347 A CN 115305347A
- Authority
- CN
- China
- Prior art keywords
- zinc ferrite
- iron boron
- neodymium iron
- zinc
- neodymium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/02—Roasting processes
- C22B1/06—Sulfating roasting
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F17/00—Compounds of rare earth metals
- C01F17/10—Preparation or treatment, e.g. separation or purification
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F17/00—Compounds of rare earth metals
- C01F17/20—Compounds containing only rare earth metals as the metal element
- C01F17/282—Sulfates
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
- C04B35/2658—Other ferrites containing manganese or zinc, e.g. Mn-Zn ferrites
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/62204—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products using waste materials or refuse
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/02—Obtaining noble metals by dry processes
- C22B11/021—Recovery of noble metals from waste materials
- C22B11/023—Recovery of noble metals from waste materials from pyrometallurgical residues, e.g. from ashes, dross, flue dust, mud, skim, slag, sludge
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/001—Dry processes
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/006—Wet processes
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3284—Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6562—Heating rate
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6567—Treatment time
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention provides a method for preparing zinc ferrite from neodymium iron boron waste, and relates to the technical field of neodymium iron boron waste recovery. A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps: s1, mixing neodymium iron boron waste and zinc sulfate, and roasting to obtain a roasted product; s2, grinding the roasted product, soaking in water, and filtering to obtain a neodymium sulfate solution and a zinc ferrite precursor; and S3, pressing and molding the zinc ferrite precursor, and roasting to obtain the zinc ferrite. According to the method for preparing the zinc ferrite from the neodymium iron boron waste, the rare earth elements in the neodymium iron boron waste can be separated from iron through selective sulfating roasting, so that a zinc ferrite substance is obtained, the yield of the zinc ferrite is high, acid wastewater and waste residues are not generated in the recovery process, the environmental protection is facilitated, and meanwhile, the obtained zinc ferrite does not contain acid, can be used for magnetic materials and has high utilization value.
Description
Technical Field
The invention relates to the technical field of neodymium iron boron waste recovery, in particular to a method for preparing zinc ferrite from neodymium iron boron waste.
Background
The neodymium iron boron magnet is widely applied to the fields of hybrid electric vehicles, wind turbines, water turbine generator sets and the like, and the life cycle of the neodymium iron boron magnet is different from 2 to 30 years according to different application fields. The neodymium iron boron magnet contains 27-32% of rare earth, 67-73% of iron, 1% of boron and other trace elements, so that the neodymium iron boron magnet can save resources and create economic value for recycling neodymium iron boron waste materials.
The utilization of the neodymium iron boron waste material comprises direct and repeated reutilization, preparation of a magnet after hydrogen crushing, pyrometallurgy, gas phase extraction, wet metallurgy and the like, wherein wet processes such as hydrochloric acid optimal dissolution, sulfuric acid full dissolution and the like are commonly used in industry. The processes are suitable for various types of magnet materials, including oxidized and unoxidized magnet materials, and have the advantages of simple process, high leaching rate of rare earth, and similarity to the extraction process of rare earth raw ore. However, a large amount of acidic wastewater and acidic leaching residues are generated, and solid waste residues cannot be effectively utilized and cause environmental pollution.
Disclosure of Invention
The invention aims to provide a method for preparing zinc ferrite from neodymium iron boron waste, which can separate rare earth elements from iron in the neodymium iron boron waste through selective sulfating roasting so as to obtain a zinc ferrite substance, has high zinc ferrite yield, does not generate acid wastewater and waste residue in the recovery process, is beneficial to environmental protection, and can be used for magnetic materials because the obtained zinc ferrite does not contain acid and has high utilization value.
The technical problem to be solved by the invention is realized by adopting the following technical scheme.
The invention provides a method for preparing zinc ferrite from neodymium iron boron waste, which comprises the following steps:
s1, mixing neodymium iron boron waste and zinc sulfate, and roasting to obtain a roasted product;
s2, grinding the roasted product, soaking in water, and filtering to obtain a neodymium sulfate solution and a zinc ferrite precursor;
and S3, pressing and molding the zinc ferrite precursor, and roasting to obtain the zinc ferrite.
The embodiment of the invention at least has the following beneficial effects:
according to the invention, zinc sulfate is used for selective sulfating roasting, acid is not used in the process, relatively less waste water is generated, and the defects of acidic waste water, environmental pollution and the like in the hydrochloric acid optimum solution method are overcome. In the roasting process, the rare earth in the neodymium iron boron waste material reacts with oxygen in the air to generate neodymium oxide and ferric oxide, then the neodymium oxide reacts with zinc sulfate to generate neodymium sulfate and zinc oxide, meanwhile, the zinc sulfate is also heated and decomposed to generate zinc oxide, and finally the ferric oxide reacts with the zinc oxide to generate zinc ferrite, namely the final roasting product mainly contains neodymium sulfate and zinc ferrite. And then, the roasted product is ground, so that the dissociation degree between the roasted products is improved, the contact area between the roasted product and water is increased, the water is favorably immersed into the roasted product in the water immersion process, neodymium sulfate in the roasted product is more conveniently dissolved in the water, the neodymium sulfate is favorably separated from zinc ferrite, and the separation effect is improved. And then, performing water leaching operation, and leaching the roasted product by water to dissolve neodymium sulfate in water, so that the separation of neodymium sulfate and zinc ferrite is realized, the process is simple, the leaching efficiency of neodymium sulfate is high, and the leaching rate is high. And finally, the filtered zinc ferrite precursor is pressed, molded and roasted, so that the purity of the zinc ferrite is improved, and the obtained zinc ferrite has better stability, can be well used as a magnetic material and is beneficial to improving the utilization value of the zinc ferrite.
Drawings
FIG. 1 is a process flow diagram of a method for preparing zinc ferrite from neodymium iron boron wastes according to the present invention;
FIG. 2 is a Gibbs free energy of reaction of rare earth oxide and iron oxide with zinc sulfate, respectively, wherein (4) represents the reaction of rare earth oxide with zinc sulfate, and (5) represents the reaction of iron oxide with zinc sulfate;
fig. 3 is an XRD pattern of zinc ferrite.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are conventional products which are not indicated by manufacturers and are commercially available.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to specific examples.
A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps:
s1, mixing neodymium iron boron waste and zinc sulfate, and roasting to obtain a roasted product;
s2, grinding the roasted product, soaking in water, and filtering to obtain a neodymium sulfate solution and a zinc ferrite precursor;
and S3, pressing and molding the zinc ferrite precursor, and roasting to obtain the zinc ferrite.
During the roasting process of the neodymium iron boron waste and zinc sulfate, the rare earth of the neodymium iron boron waste is sulfated and roasted to generate rare earth sulfate, iron in the neodymium iron boron waste is converted into oxide, the zinc sulfate is converted into zinc oxide, and the reaction possibly occurring in the selective sulfating roasting process is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +3ZnSO 4 ＝Fe 2 (SO 4 ) 3 +3ZnO (5)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (6)
in the roasting process, the rare earth and the iron in the neodymium iron boron waste are subjected to oxidizing roasting according to the reactions (1) and (2), the zinc sulfate is subjected to decomposition reaction according to the reaction (3) to release sulfur trioxide, and meanwhile, the zinc sulfate and the rare earth and the iron in the neodymium iron boron waste are respectively subjected to the reactions (4) and (5).
However, as shown in FIG. 2, FIG. 2 is a graph showing the standard Gibbs free energy at different temperatures at normal pressures of reactions (4) and (5), and in the temperature range of 273 to 1273K, the standard Gibbs free energy of reaction (4) is less than zero, and theoretically the reaction proceeds rightward, while the standard Gibbs free energy of reaction (5) is greater than zero, and theoretically the reaction cannot proceed rightward.
Therefore, the method can realize selective sulfation of the rare earth elements in the neodymium iron boron waste material in the roasting process, so that the rare earth is converted into soluble rare earth sulfate, and the iron is converted into oxide, namely the iron is not converted into ferric sulfate in the reaction process.
The zinc sulfate is used for selective sulfating roasting, acid is not used in the process, relatively less waste water is generated, and the defects of acidic waste water, environmental pollution and the like in the hydrochloric acid optimum-capacity method are overcome. In the roasting process, the rare earth in the neodymium iron boron waste material reacts with oxygen in the air to generate neodymium oxide and iron oxide, then the neodymium oxide reacts with zinc sulfate to generate neodymium sulfate and zinc oxide, meanwhile, the zinc sulfate is also heated and decomposed to generate zinc oxide, and finally the iron oxide reacts with the zinc oxide to generate zinc ferrite, namely the final roasting product mainly contains the neodymium sulfate and the zinc ferrite.
In the roasting process, zinc sulfate can be decomposed to generate zinc oxide and sulfur trioxide, and tail gas is required to be treated during actual preparation so as to prevent sulfur trioxide gas from dissipating in the air to cause environmental pollution.
And then, the roasted product is ground, so that the dissociation degree between the roasted products is improved, the contact area between the roasted product and water is increased, the water is favorably immersed into the roasted product in the water immersion process, neodymium sulfate in the roasted product is more conveniently dissolved in the water, the neodymium sulfate is favorably separated from zinc ferrite, and the separation effect is improved. And then carrying out water leaching operation, and leaching the roasted product by water to dissolve neodymium sulfate in water, so as to realize the separation of neodymium sulfate and zinc ferrite, and the process is simple, the leaching efficiency of neodymium sulfate is high, and the leaching rate is high.
And finally, the filtered zinc ferrite precursor is pressed, molded and roasted, so that the purity of the zinc ferrite is improved, and the obtained zinc ferrite has better stability, can be well used as a magnetic material and is beneficial to improving the utilization value of the zinc ferrite.
Therefore, according to the method for preparing the zinc ferrite from the neodymium iron boron waste, provided by the invention, the rare earth elements in the neodymium iron boron waste can be separated from iron through selective sulfating roasting, and meanwhile, the iron cannot be converted into ferric sulfate, so that the iron oxide and the zinc oxide are more easily reacted, a zinc ferrite substance is obtained, the yield of the zinc ferrite is high, acid wastewater and waste residues cannot be generated in the recovery process, the environmental protection is facilitated, and meanwhile, the obtained zinc ferrite does not contain acid, can be used for magnetic materials, and has high utilization value.
In addition, compared with the method of directly carrying out sulfation treatment by using sulfuric acid, the method of the invention adopts zinc sulfate treatment to avoid waste residues with higher acidity, does not need to carry out retreatment on the acid waste residues to meet the pollutant emission standard, can avoid environmental pollution, can reduce production cost, has higher practicability, can recycle zinc ferrite in a large scale, and has higher economic benefit.
In S1, the roasting temperature is 500-800 ℃, and the time is 0.5-4h. Under this calcination temperature, neodymium iron boron waste material is changeed and is reacted with the oxygen in the air and generate neodymium oxide and ferric oxide, can improve the reaction rate of neodymium oxide and zinc sulfate simultaneously for the generation rate of neodymium sulfate and zinc oxide, and then accelerate the reaction rate of ferric oxide and zinc oxide, thereby let the formation speed of zinc ferrite faster, help improving the preparation rate of zinc ferrite. In the time, neodymium and iron in the neodymium-iron-boron waste can react with air more fully, so that the content of neodymium oxide and iron oxide is increased; can let neodymium oxide and zinc sulfate react more fully to improve the content of neodymium sulfate and zinc oxide, and then let iron oxide and zinc oxide react more fully, in order to improve zinc ferrite's formation volume.
The mass of the zinc sulfate is 1-1.05 times of the theoretical amount of the zinc ferrite obtained after the neodymium iron boron waste is treated. The method comprises the following steps of preparing zinc ferrite, namely, detecting the content of iron in neodymium iron boron waste, wherein the theoretical amount of the zinc ferrite refers to the content of the iron in the neodymium iron boron waste, detecting the content of the iron in the neodymium iron boron waste before preparing the zinc ferrite, and preparing zinc sulfate according to the content of the iron. Under the proportion, the zinc sulfate can react with the neodymium oxide more fully so as to improve the contents of the neodymium sulfate and the zinc oxide, improve the leaching rate of the neodymium sulfate, improve the content of the zinc oxide, ensure the zinc oxide to react with the ferric oxide more fully, and improve the content of zinc ferrite.
The zinc sulfate is industrial zinc sulfate with the purity of more than 99 percent. By adopting the zinc sulfate with the purity, the reaction rate of the zinc sulfate and the neodymium oxide can be increased, so that the rate of preparing the zinc ferrite is increased, and the purity of the zinc ferrite is increased.
Before mixing the neodymium iron boron waste and the zinc sulfate, grinding the neodymium iron boron waste to 190-210 meshes. Through grinding the neodymium iron boron waste into powder, can increase the area of contact of neodymium iron boron powder and air and zinc sulfate, not only be favorable to letting neodymium in the neodymium iron boron waste and iron and the oxygen in the air to react and generate iron oxide and neodymium oxide like this, still be favorable to neodymium oxide and zinc sulfate to react and generate neodymium sulfate and zinc oxide, and then accelerate each reaction rate in the calcination process for the speed of preparation zinc ferrite is faster.
In S2, when the mixture is soaked in water, the temperature is room temperature, the liquid-solid ratio is 3-5, and the time is 0.5-3h. In this example, the room temperature was 30. + -. 2 ℃. In addition, in the water leaching process, stirring is needed, and ultrasonic waves can be adopted for oscillation, so that the speed of water leaching of the roasted product can be increased, the neodymium sulfate is dissolved in water, and the separation speed of neodymium sulfate and zinc ferrite precursors is increased. Under the liquid-solid ratio and the time, the roasted product can be ensured to be fully soaked by water, the movement rate of the water can be accelerated by stirring and oscillating, and the neodymium sulfate in the product can be more conveniently carried out by the water soaked in the roasted product, so that the separation effect and the separation rate are improved.
In addition, the neodymium sulfate and the zinc ferrite precursor are separated by adopting a water immersion method, so that other impurities can be avoided, and the separated zinc ferrite precursor has higher purity and higher utilization value.
In S3, cold press molding is adopted during press molding, the pressure is 6.5-7.5MPa, and the blank size is phi (20 +/-0.2) mm x (10 +/-0.2) mm. By pressing the zinc ferrite precursor, the zinc oxide, the iron oxide and the zinc ferrite in the zinc ferrite precursor can be contacted more closely, and the zinc oxide and the iron oxide which are remained can react to generate the zinc ferrite in the subsequent roasting process, so that the purity and the content of the zinc ferrite are further improved.
In S3, the temperature is 800-1000 ℃ during roasting, the time is 2-6h, and the roasting temperature rise rate is 5 ℃/min. Thus, the zinc oxide and the iron oxide are facilitated to react, and the stability of the zinc ferrite can be further enhanced through high-temperature sintering, so that the zinc ferrite has higher content and higher purity.
The features and properties of the present invention are described in further detail below with reference to examples.
Example 1
A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps:
s1, grinding the neodymium iron boron waste to 200 meshes (74 micrometers), wherein powder with the particle size of 200 meshes accounts for more than 90%, the content of rare earth in the neodymium iron boron waste is 30%, and the content of iron in the neodymium iron boron waste is 66%; according to the constitution of zinc ferrite (ZnFe) 2 O 4 ) Adding zinc sulfate (ZnSO) 4 ) And zinc sulfate is 1 time of the theoretical amount of zinc ferrite, neodymium iron boron powder and zinc sulfate are uniformly mixed, a muffle furnace is adopted to heat to 750 ℃ for roasting for 120min, a roasted product is obtained, and the reaction generated in the roasting process is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (5)
s2, cooling and grinding the roasted product, leaching with deionized water at room temperature (30 ℃), wherein the liquid-solid ratio is 5/1, the leaching time is 60min, the stirring speed is 200r/min, and filtering and separating are carried out after the leaching is finished to obtain a neodymium sulfate solution and a zinc ferrite precursor; the leaching rate of rare earth of the roasting product is 96.5 percent, the leaching rate of zinc is 0.5 percent, and the leaching rate of iron is 0.01 percent;
and S3, cold-pressing and molding the zinc ferrite precursor, wherein the size of the blank is phi 20mm multiplied by 10mm, the pressure is 7.5MPa, and then sintering for 6h in a muffle furnace at 900 ℃, and the heating rate in the sintering process is 5 ℃/min, so that the zinc ferrite is obtained.
Example 2
A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps:
s1, grinding the neodymium iron boron waste to 200 meshes (74 mu m), wherein the powder with the particle size of 200 meshes accounts for more than 90%, the rare earth content in the neodymium iron boron waste is 30%, the iron content in the neodymium iron boron waste is 66%, and zinc ferrite (ZnFe) is formed according to the formula 2 O 4 ) Adding zinc sulfate (ZnSO) 4 ) And zinc sulfate is 1 time of the theoretical amount of zinc ferrite, neodymium iron boron powder and zinc sulfate are uniformly mixed, a muffle furnace is adopted to heat up to 800 ℃ for roasting for 60min, a roasted product is obtained, and the reaction generated in the roasting process is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (5)
s2, cooling and grinding the roasted product, leaching with deionized water at room temperature (30 ℃), wherein the liquid-solid ratio is 5/1, the leaching time is 30min, the stirring speed is 200r/min, and filtering and separating are carried out after the leaching is finished to obtain a neodymium sulfate solution and a zinc ferrite precursor; the leaching rate of rare earth of the roasting product is 97.3 percent, the leaching rate of zinc is 0.3 percent, and the leaching rate of iron is 0.01 percent;
and S3, cold-press molding the zinc ferrite precursor, wherein the size of the blank is phi 20mm multiplied by 10mm, the pressure is 7.5MPa, then sintering is carried out for 5h in a muffle furnace at 1000 ℃, and the heating rate in the sintering process is 5 ℃/min, so as to obtain the zinc ferrite.
Example 3
A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps:
s1, grinding the neodymium iron boron waste to 200 meshes (74 mu m), wherein the powder with the particle size of 200 meshes accounts for more than 90%, the rare earth content in the neodymium iron boron waste is 30%, the iron content in the neodymium iron boron waste is 66%, and zinc ferrite (ZnFe) is formed according to the formula 2 O 4 ) Adding zinc sulfate (ZnSO) 4 ) And zinc sulfate is 1.01 times of the theoretical amount of zinc ferrite, neodymium iron boron powder and zinc sulfate are uniformly mixed, a muffle furnace is adopted to heat to 700 ℃ for roasting for 60min, and a roasted product is obtained, wherein the reaction in the roasting process is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (5)
s2, cooling and grinding the roasted product, leaching with deionized water at room temperature (30 ℃), wherein the liquid-solid ratio is 3/1, the leaching time is 60min, the stirring speed is 200r/min, and filtering and separating after the leaching is finished to obtain a neodymium sulfate solution and a zinc ferrite precursor; the leaching rate of rare earth of a roasting product is 96.1 percent, the leaching rate of zinc is 0.2 percent, and the leaching rate of iron is 0.01 percent;
and S3, cold-press molding the zinc ferrite precursor, wherein the size of the blank is phi 20mm multiplied by 10mm, the pressure is 6.5MPa, then sintering is carried out for 6h in a muffle furnace at 1000 ℃, and the heating rate in the sintering process is 5 ℃/min, so as to obtain the zinc ferrite.
Example 4
A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps:
s1, grinding the neodymium iron boron waste to 190 meshes, wherein powder with the particle size of 190 meshes accounts for more than 90%, the content of rare earth in the neodymium iron boron waste is 30%, the content of iron in the neodymium iron boron waste is 66%, and zinc ferrite (ZnFe) is formed according to the formula 2 O 4 ) Adding zinc sulfate (ZnSO) 4 ) Zinc sulfate is 1.05 times of the theoretical amount of zinc ferrite, neodymium iron boron powder and zinc sulfate are uniformly mixed, a muffle furnace is adopted to heat up to 650 ℃ for roasting for 60min, a roasted product is obtained, and the reaction in the roasting process is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (5)
s2, cooling and grinding the roasted product, leaching with deionized water at room temperature (28 ℃), wherein the liquid-solid ratio is 4/1, the leaching time is 60min, the stirring speed is 200r/min, and filtering and separating after the leaching is finished to obtain a neodymium sulfate solution and a zinc ferrite precursor; the leaching rate of rare earth of a roasting product is 95.8 percent, the leaching rate of zinc is 0.3 percent, and the leaching rate of iron is 0.01 percent;
and S3, cold-press molding the zinc ferrite precursor, wherein the size of the blank is phi 20mm multiplied by 10mm, the pressure is 7MPa, then sintering is carried out for 6h in a muffle furnace at 1000 ℃, and the heating rate in the sintering process is 5 ℃/min, so as to obtain the zinc ferrite.
Example 5
A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps:
s1, grinding the neodymium iron boron waste to 210 meshes, wherein the powder with the particle size of 210 meshes accounts for more than 90%, the rare earth content in the neodymium iron boron waste is 30%, the iron content in the neodymium iron boron waste is 66%, and zinc ferrite (ZnFe) is formed according to the formula 2 O 4 ) Adding zinc sulfate (ZnSO) 4 ) And zinc sulfate is 1.02 times of the theoretical amount of zinc ferrite, neodymium-iron-boron powder and zinc sulfate are uniformly mixed, a muffle furnace is adopted to heat to 780 ℃ for roasting for 60min, a roasted product is obtained, and the reaction in the roasting process is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (5)
s2, cooling and grinding the roasted product, leaching with deionized water at room temperature (32 ℃), wherein the liquid-solid ratio is 3/1, the leaching time is 60min, the stirring speed is 200r/min, and filtering and separating are carried out after the leaching is finished to obtain a neodymium sulfate solution and a zinc ferrite precursor; the leaching rate of rare earth of the roasted product is 96.0 percent, the leaching rate of zinc is 0.2 percent, and the leaching rate of iron is 0.01 percent;
and S3, cold-press molding the zinc ferrite precursor, wherein the size of the blank is phi 20mm multiplied by 10mm, the pressure is 6.8MPa, then sintering is carried out for 6h in a muffle furnace at 1000 ℃, and the heating rate in the sintering process is 5 ℃/min, so as to obtain the zinc ferrite.
Example 6
A method for preparing zinc ferrite from neodymium iron boron waste comprises the following steps:
s1, grinding the neodymium iron boron waste to 200 meshes (74 mu m), wherein the powder with the particle size of 200 meshes accounts for more than 90%, and the neodymium iron boronThe waste material contains 30% of rare earth and 66% of iron, and is composed of zinc ferrite (ZnFe) 2 O 4 ) Adding zinc sulfate (ZnSO) 4 ) Zinc sulfate is 1.04 times of the theoretical amount of zinc ferrite, neodymium iron boron powder and zinc sulfate are uniformly mixed, a muffle furnace is adopted to heat up to 500 ℃ for roasting for 60min, and a roasted product is obtained, wherein the reaction in the roasting process is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (5)
s2, cooling and grinding the roasted product, leaching with deionized water at room temperature (28 ℃), wherein the liquid-solid ratio is 3/1, the leaching time is 60min, the stirring speed is 200r/min, and filtering and separating after the leaching is finished to obtain a neodymium sulfate solution and a zinc ferrite precursor; the leaching rate of rare earth of a roasting product is 95.7 percent, the leaching rate of zinc is 0.3 percent, and the leaching rate of iron is 0.02 percent;
and S3, cold-press molding the zinc ferrite precursor, wherein the size of the blank is phi 20mm multiplied by 10mm, the pressure is 6.5MPa, then sintering is carried out for 2h in a muffle furnace at 800 ℃, and the heating rate in the sintering process is 5 ℃/min, so as to obtain the zinc ferrite.
Test results
1. The reaction which may occur in the roasting process of the neodymium iron boron waste and the zinc sulfate is judged, and the reaction which may occur is as follows:
Nd+O 2 (g)＝Nd 2 O 3 (1)
Fe+O 2 (g)＝Fe 2 O 3 (2)
2ZnSO 4 ＝ZnO+SO 3 (g) (3)
Nd 2 O 3 +3ZnSO 4 ＝Nd 2 (SO 4 ) 3 +3ZnO (4)
Fe 2 O 3 +3ZnSO 4 ＝Fe 2 (SO 4 ) 3 +3ZnO (5)
Fe 2 O 3 +ZnO＝ZnFe 2 O 4 (6)
while, as shown in FIG. 2, FIG. 2 shows a schematic diagram of the standard Gibbs free energy at different temperatures at atmospheric pressure for reaction (4) and reaction (5). Wherein, in the temperature range of 273-1273K, the standard Gibbs free energy of the reaction (4) is less than zero, the reaction theoretically proceeds to the right, the standard Gibbs free energy of the reaction (5) is more than zero, and the reaction theoretically cannot proceed to the right.
The results of fig. 2 show that: the method can realize selective sulfation of rare earth elements in the neodymium iron boron waste in the roasting process, so that the rare earth is converted into soluble rare earth sulfate, and iron is converted into oxide, namely, the iron is not converted into ferric sulfate in the reaction process.
2. The zinc ferrite prepared by the embodiment of the invention is subjected to XRD detection:
as shown in fig. 3, the detected substance was zinc ferrite as seen from the diffraction peak in fig. 3. The zinc ferrite can be prepared by the method for preparing the zinc ferrite from the neodymium iron boron waste.
In conclusion, according to the method for preparing the zinc ferrite from the neodymium iron boron waste, provided by the embodiment of the invention, zinc sulfate is used for selective sulfating roasting, acid is not used in the process, relatively less wastewater is generated, and the defects of acidic wastewater, environmental pollution and the like in the hydrochloric acid optimum solution are overcome. In the roasting process, the rare earth in the neodymium iron boron waste material reacts with oxygen in the air to generate neodymium oxide and ferric oxide, then the neodymium oxide reacts with zinc sulfate to generate neodymium sulfate and zinc oxide, meanwhile, the zinc sulfate is also heated and decomposed to generate zinc oxide, and finally the ferric oxide reacts with the zinc oxide to generate zinc ferrite, namely the final roasting product mainly contains neodymium sulfate and zinc ferrite.
And then, the roasted product is ground, so that the dissociation degree between the roasted products is improved, the contact area between the roasted product and water is increased, the water is favorably immersed into the roasted product in the water immersion process, neodymium sulfate in the roasted product is more conveniently dissolved in the water, the neodymium sulfate is favorably separated from zinc ferrite, and the separation effect is improved. And then carrying out water leaching operation, and leaching the roasted product by water to dissolve neodymium sulfate in water, so as to realize the separation of neodymium sulfate and zinc ferrite, and the process is simple, the leaching efficiency of neodymium sulfate is high, and the yield is high.
And finally, the filtered zinc ferrite precursor is pressed, molded and roasted, so that the purity of the zinc ferrite is improved, and the obtained zinc ferrite has better stability, can be well used as a magnetic material and is beneficial to improving the utilization value of the zinc ferrite.
The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
Claims (10)
1. A method for preparing zinc ferrite from neodymium iron boron waste is characterized by comprising the following steps:
s1, mixing neodymium iron boron waste and zinc sulfate, and roasting to obtain a roasted product;
s2, grinding the roasted product, soaking in water, and filtering to obtain a neodymium sulfate solution and a zinc ferrite precursor;
and S3, pressing and molding the zinc ferrite precursor, and roasting to obtain the zinc ferrite.
2. The method for preparing the zinc ferrite from the neodymium iron boron wastes according to claim 1, wherein in S1, the roasting temperature is 500-800 ℃, and the roasting time is 0.5-4h.
3. The method for preparing the zinc ferrite from the neodymium iron boron waste material according to claim 1, wherein the mass of the zinc sulfate is 1-1.05 times of the theoretical amount of the zinc ferrite obtained after the neodymium iron boron waste material is treated.
4. The method for preparing zinc ferrite from neodymium iron boron wastes according to claim 3, characterized in that the zinc sulfate is industrial zinc sulfate with a purity of more than 99%.
5. The method for preparing the zinc ferrite from the neodymium iron boron wastes according to claim 1, wherein before mixing the neodymium iron boron wastes and the zinc sulfate, the method further comprises grinding the neodymium iron boron wastes to 190-210 meshes.
6. The method for preparing zinc ferrite from neodymium iron boron wastes according to claim 1, wherein in S2, when the wastes are immersed in water, the temperature is room temperature, the liquid-solid ratio is 3-5, and the time is 0.5-3h.
7. The method for preparing zinc ferrite from neodymium iron boron wastes according to claim 1, wherein in S3, a cold press molding mode is adopted during press molding, and the pressure is 6.5-7.5MPa.
8. The method for preparing zinc ferrite from neodymium iron boron wastes according to claim 7, wherein the size of the blank is phi (20 plus or minus 0.2) mm x (10 plus or minus 0.2) mm during the press forming.
9. The method for preparing zinc ferrite from neodymium iron boron wastes according to claim 8, characterized in that in S3, the roasting temperature is 800-1000 ℃ and the roasting time is 2-6h.
10. The method for preparing zinc ferrite from neodymium iron boron wastes according to claim 9, characterized in that in S3, the roasting temperature rise rate is 5 ℃/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211036080.7A CN115305347A (en) | 2022-08-27 | 2022-08-27 | Method for preparing zinc ferrite from neodymium iron boron waste |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211036080.7A CN115305347A (en) | 2022-08-27 | 2022-08-27 | Method for preparing zinc ferrite from neodymium iron boron waste |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115305347A true CN115305347A (en) | 2022-11-08 |
Family
ID=83865572
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211036080.7A Pending CN115305347A (en) | 2022-08-27 | 2022-08-27 | Method for preparing zinc ferrite from neodymium iron boron waste |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115305347A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996005329A1 (en) * | 1994-08-15 | 1996-02-22 | R & O Mining Processing Ltd. | Hydrometallurgical conversion of zinc sulfide to sulfate from zinc sulfide containing ores and concentrates |
| CN104233373A (en) * | 2013-06-13 | 2014-12-24 | 无锡市森信精密机械厂 | Zinc smelting technology for low-zinc high-iron roasting ore by wet method |
| CN108103318A (en) * | 2017-12-24 | 2018-06-01 | 江西理工大学 | A kind of method of Selectively leaching neodymium iron boron greasy filth middle rare earth |
| CN111187927A (en) * | 2020-02-18 | 2020-05-22 | 内蒙古科技大学 | Method for selectively sulfating and recovering rare earth in neodymium iron boron waste |
| CN112194187A (en) * | 2020-09-25 | 2021-01-08 | 南京理工大学 | Method for synthesizing zinc ferrite spherical nano material by premixed flame |
| CN113667819A (en) * | 2021-07-15 | 2021-11-19 | 江西理工大学 | Method for separating and recycling neodymium iron boron waste materials through zinc roasting |
-
2022
- 2022-08-27 CN CN202211036080.7A patent/CN115305347A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996005329A1 (en) * | 1994-08-15 | 1996-02-22 | R & O Mining Processing Ltd. | Hydrometallurgical conversion of zinc sulfide to sulfate from zinc sulfide containing ores and concentrates |
| CN104233373A (en) * | 2013-06-13 | 2014-12-24 | 无锡市森信精密机械厂 | Zinc smelting technology for low-zinc high-iron roasting ore by wet method |
| CN108103318A (en) * | 2017-12-24 | 2018-06-01 | 江西理工大学 | A kind of method of Selectively leaching neodymium iron boron greasy filth middle rare earth |
| CN111187927A (en) * | 2020-02-18 | 2020-05-22 | 内蒙古科技大学 | Method for selectively sulfating and recovering rare earth in neodymium iron boron waste |
| CN112194187A (en) * | 2020-09-25 | 2021-01-08 | 南京理工大学 | Method for synthesizing zinc ferrite spherical nano material by premixed flame |
| CN113667819A (en) * | 2021-07-15 | 2021-11-19 | 江西理工大学 | Method for separating and recycling neodymium iron boron waste materials through zinc roasting |
Non-Patent Citations (1)
| Title |
|---|
| 张朝晖，李林波，韦武强: "冶金资源综合利用", 冶金工业出版社, pages: 260 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106848472B (en) | Method for recycling lithium from waste lithium iron phosphate batteries | |
| CN101508471B (en) | Process for producing cobaltic-cobaltous oxide | |
| CN110028111B (en) | Preparation method of ternary positive electrode material precursor and lithium carbonate | |
| CN106048251B (en) | A kind of process of clean and effective processing setting form | |
| CN111979415B (en) | Method for recovering waste lithium cobaltate positive electrode material without strong acid leaching | |
| CN111206153A (en) | Method for recovering positive electrode material of nickel-cobalt-manganese acid lithium battery | |
| CN111187927A (en) | Method for selectively sulfating and recovering rare earth in neodymium iron boron waste | |
| CN113415813A (en) | Method for recovering lithium nickel cobalt manganese from waste ternary battery material | |
| CN101007656A (en) | Waste molybdenum nickel cobalt catalyst utilization method for environmental protection | |
| CN101717858A (en) | Method for extracting molybdenum, nickel, vanadium and ferrum from polymetallic black-shale paragentic minerals | |
| CN114684801A (en) | Method for preparing high-purity iron phosphate by using pyrite cinder | |
| CN108439473A (en) | A kind of method that tungstenic scrap hard alloy prepares nanometer tungsten oxide | |
| CN111088428A (en) | Leaching system and leaching method for recovering valuable metals of waste lithium cobalt oxide batteries | |
| CN106957965A (en) | A kind of preparation method of iron oxide product | |
| CN103834814A (en) | Method for preparing iron oxide red by using copper nickel slag | |
| CN109234521B (en) | Method for extracting vanadium again from vanadium-containing byproduct iron vanadate | |
| CN114560767B (en) | Method for preparing ferrous oxalate by siderite | |
| CN114789994B (en) | Method for preparing battery-grade ferric phosphate by extracting laterite-nickel ore | |
| CN115305347A (en) | Method for preparing zinc ferrite from neodymium iron boron waste | |
| CN115159490A (en) | Method for recycling iron phosphate slag | |
| CN115652077A (en) | Method for selectively separating and recovering lithium and manganese from waste lithium manganate battery | |
| CN112456461B (en) | Method for preparing battery-grade flaky iron phosphate by using cobalt-iron leaching solution | |
| CN114604836A (en) | Recovery method for waste lithium iron phosphate positive and negative mixed powder through ultrasonic high-energy oxygen treatment | |
| CN114976336A (en) | Method for leaching lithium from lithium battery positive electrode material | |
| CN107381646B (en) | The method for preparing mangano-manganic oxide using acid-soluble manganese ore recycled based on sulphur, ammonia |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |