阅读说明：本技术 一种从钕铁硼废料中高效提铁富集稀土元素的方法 (Method for efficiently extracting iron from neodymium iron boron waste to enrich rare earth elements ) 是由 李博 王兵 李上奎 于缘宝 于 2020-10-13 设计创作，主要内容包括：本发明公开了一种从钕铁硼废料中高效提铁富集稀土元素的方法,主要设备和材料为回转式焙烧窑、钕铁硼废料、硫酸盐、颚式破碎机、一氧化碳和合成釜等；制备方法如下,将钕铁硼废料在回转式焙烧窑中于600-800℃进行氧化焙烧,得到相应的混合氧化物,磨细,将焙砂用饱和的硫酸盐、硫酸钙、硫酸镁、硫酸镍等溶液处理,使焙砂中硫酸盐含量达到2%,在还原温度为800-950℃,还原时间为四小时,配碳比为30％的条件下,对焙砂进行还原,得到还原块料,该步骤有两个目的,选择性还原,铁的还原率达到95%以上,本发明具有同步高效提取、高值回用钕铁硼废料中铁金属并富集稀土金属、工艺流程短、环境友好、产物价值高的优点。(The invention discloses a method for efficiently extracting iron from neodymium iron boron waste to enrich rare earth elements, wherein main equipment and materials comprise a rotary roasting kiln, neodymium iron boron waste, sulfate, a jaw crusher, carbon monoxide, a synthesis kettle and the like; the preparation method comprises the following steps of carrying out oxidizing roasting on neodymium iron boron waste in a rotary roasting kiln at 800 ℃ with 600-.)

1. A method for efficiently extracting iron from neodymium iron boron waste materials and enriching rare earth elements is characterized by comprising the following steps: the main equipment and materials are a rotary roasting kiln, neodymium iron boron waste, sulfate, a jaw crusher, carbon monoxide, a synthesis kettle and the like; the preparation method comprises the following steps:

oxidizing and roasting the neodymium iron boron waste in a rotary roasting kiln to obtain a corresponding mixed oxide, grinding to 200 roasted products, wherein the reaction formula of the roasting process is as follows: nd + O2 → Nd2O3 and Fe + O2 → Fe2O 3;

step (2), treating the calcine with saturated sulfate (calcium sulfate, magnesium sulfate, nickel sulfate and the like) solution to enable the sulfate content in the calcine to reach 2%;

reducing the calcine under the conditions that the reduction temperature is 800-950 ℃, the reduction time is four hours and the carbon ratio is 30 percent to obtain a reduction lump material; the reduction reaction formula is as follows: fe2O3+ C → Fe + CO2 and CaSO4 → CaO + SO 3;

crushing the reducing lump material by using a jaw crusher to obtain a granularity reducing lump material;

step (5) the reduction lump material and carbon monoxide are subjected to synthetic reaction in a synthetic kettle to generate iron pentacarbonyl and synthetic residues, wherein the iron pentacarbonyl is used for producing micron-sized carbonyl iron powder with high added value; the rare earth elements in the synthetic residue are enriched, and the grade is improved from 30% to 70%.

2. A method for efficiently extracting iron from neodymium iron boron waste materials and enriching rare earth elements is characterized by comprising the following steps: the oxidizing roasting temperature of the neodymium iron boron waste material in the step (1) in the rotary roasting kiln is 600-800 ℃.

3. A method for efficiently extracting iron from neodymium iron boron waste materials and enriching rare earth elements is characterized by comprising the following steps: the step (3) comprises (i) selective reduction: the reduction rate of iron reaches more than 95 percent, and the rare earth elements are not reduced basically; secondly, sulfate radicals in the sulfate are decomposed to generate sulfur trioxide and the sulfur trioxide is absorbed by reduced iron, and the iron contains 0.2-0.6% of sulfur element, so that the speed of the oxo-synthesis reaction can be greatly improved.

4. A method for efficiently extracting iron from neodymium iron boron waste materials and enriching rare earth elements is characterized by comprising the following steps: the granularity of the reduced lump material in the step (4) is less than 30 mm.

5. A method for efficiently extracting iron from neodymium iron boron waste materials and enriching rare earth elements is characterized by comprising the following steps: and (5) carrying out synthetic reaction in a synthetic kettle under the condition of 11.0-30.0 MPa.

Technical Field

The invention relates to the technical field of magnetic materials, in particular to a method for efficiently extracting iron from neodymium iron boron waste materials to enrich rare earth elements.

Background

China is a big country for producing neodymium iron boron magnetic materials, at present, the annual output of neodymium iron boron still increases at a speed of about 20%, however, neodymium iron boron waste materials with the mass of about 30 wt% of the raw materials are generated in the production process of neodymium iron boron magnets, and the neodymium iron boron waste materials comprise turning blocks, oil-immersed waste materials and the like. Neodymium iron boron scrap is reported to contain about 30% rare earth elements (with neodymium accounting for about 90%, the balance being other rare earth elements), and about 60% -70% iron. Therefore, how to realize the comprehensive utilization of the neodymium iron boron waste material and extract the metal elements with high value from the neodymium iron boron waste material not only reasonably utilizes resources, but also reduces the environmental pollution, has long-term strategic value for industrial development and is beneficial to realizing the benign and healthy development of the industry in China;

at present, the recovery and extraction method of high-value elements in neodymium iron boron waste mainly comprises a vacuum melting method, a sulfuric acid method, an electroreduction method, a hydrochloric acid method, a hydrometallurgy method and the like. The wet metallurgy treatment process is a method for separating impurities from rare earth by utilizing a large amount of acid liquor and alkali liquor through solvent extraction and precipitation separation, so as to achieve the purpose of recovering and treating the rare earth, is widely suitable for treating neodymium iron boron waste materials with different components and different forms, and is the most widely applied method at present. However, the process for treating neodymium iron boron waste based on the method needs to complete leaching and regeneration and reuse of rare earth step by step, although the method can obtain rare earth oxide with high purity, the whole recovery process has the defects of long process and low rare earth yield, most of the existing treatment processes still only recover rare earth elements in the waste, and neglect the regeneration and utilization of rich iron elements (iron in the neodymium iron boron waste accounts for about 60% -70%), the iron slag after leaching is only treated as an iron-making raw material, and the high-value utilization of iron resources is difficult to realize: therefore, a method for efficiently extracting iron from neodymium iron boron waste materials and enriching rare earth elements is more needed.

Disclosure of Invention

The invention aims to provide a method for efficiently extracting iron and enriching rare earth elements from neodymium iron boron waste, which has the advantages of synchronous efficient extraction, high-value recycling of iron metal and rare earth metal in the neodymium iron boron waste, short process flow, environmental friendliness and high product value, and solves the problems in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme: a method for efficiently extracting iron from neodymium iron boron waste to enrich rare earth elements comprises the main equipment and materials of a rotary roasting kiln, neodymium iron boron waste, sulfate, a jaw crusher, carbon monoxide, a synthesis kettle and the like; the preparation method comprises the following steps;

the manufacturing steps are as follows:

oxidizing and roasting the neodymium iron boron waste in a rotary roasting kiln to obtain a corresponding mixed oxide, grinding to 200 roasted products, wherein the reaction formula of the roasting process is as follows: nd + O2 → Nd2O3 and Fe + O2 → Fe2O 3;

step (2), treating the calcine with saturated sulfate (calcium sulfate, magnesium sulfate, nickel sulfate and the like) solution to enable the sulfate content in the calcine to reach 2%;

reducing the calcine under the conditions that the reduction temperature is 800-950 ℃, the reduction time is four hours and the carbon ratio is 30 percent to obtain a reduction lump material; the reduction reaction formula is as follows: fe2O3+ C → Fe + CO2 and CaSO4 → CaO + SO 3;

crushing the reducing lump material by using a jaw crusher to obtain a granularity reducing lump material;

step (5) the reduction lump material and carbon monoxide are subjected to synthetic reaction in a synthetic kettle to generate iron pentacarbonyl and synthetic residues, wherein the iron pentacarbonyl is used for producing micron-sized carbonyl iron powder with high added value; the rare earth elements in the synthetic residue are enriched, and the grade is improved from 30% to 70%.

Preferably, the oxidizing roasting temperature of the neodymium iron boron waste material obtained in the step (1) in the rotary roasting kiln is 600-800 ℃.

Preferably, said step (3) comprises (i) selective reduction: the reduction rate of iron reaches more than 95 percent, and the rare earth elements are not reduced basically; secondly, sulfate radicals in the sulfate are decomposed to generate sulfur trioxide and the sulfur trioxide is absorbed by reduced iron, and the iron contains 0.2-0.6% of sulfur element, so that the speed of the oxo-synthesis reaction can be greatly improved.

Preferably, the particle size of the reduced lump material in the step (4) is less than 30 mm.

Preferably, the synthesis reaction is carried out in the synthesis kettle of the step (5) under the condition of 11.0-30.0 MPa.

Compared with the prior art, the invention has the following beneficial effects: the method for efficiently extracting iron from neodymium iron boron waste to enrich rare earth elements; oxidizing and roasting neodymium iron boron waste in a rotary roasting kiln to obtain corresponding mixed oxide, grinding, treating the roasted product with saturated sulfate, calcium sulfate, magnesium sulfate, nickel sulfate and other solutions, reducing the roasted product to obtain reduced lump material, wherein the reduction rate of iron reaches over 95 percent, rare earth elements are not reduced basically, sulfate radicals in the sulfate are decomposed to generate sulfur trioxide and are absorbed by reduced iron, the iron contains 0.2-0.6 percent of sulfur elements, the speed of the oxo-synthesis reaction can be greatly improved, crushing the reduced lump material by using a jaw crusher, carrying out the synthetic reaction on the reduced lump material and carbon monoxide in a synthetic kettle to generate iron pentacarbonyl and synthetic residue, the iron pentacarbonyl is used for producing high-value carbonyl iron powder, the rare earth elements in the synthetic residue are enriched, and the extraction rate of iron in the comprehensive step reaches over 90 percent, the grade of rare earth elements in the synthetic residue is enriched to be close to 70 percent and is used as a high-grade neodymium iron boron raw material for external treatment; the method has the advantages of synchronous and efficient extraction, high-value recycling of iron metal and rare earth metal in the neodymium iron boron waste, short process flow, environmental friendliness and high product value.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments formed by the features of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative work belong to the protection scope of the present invention.

Example 1:

a method for efficiently extracting iron from neodymium iron boron waste to enrich rare earth elements, a method for efficiently extracting iron from neodymium iron boron waste to enrich rare earth elements, main equipment and materials are a rotary roasting kiln, neodymium iron boron waste, sulfate, a jaw crusher, carbon monoxide, a synthesis kettle and the like; the preparation method comprises the following steps;

the manufacturing steps are as follows:

oxidizing and roasting the neodymium iron boron waste in a rotary roasting kiln to obtain a corresponding mixed oxide, grinding to 200 roasted products, wherein the reaction formula of the roasting process is as follows: nd + O2 → Nd2O3 and Fe + O2 → Fe2O 3;

step (2), treating the calcine with saturated sulfate (calcium sulfate, magnesium sulfate, nickel sulfate and the like) solution to enable the sulfate content in the calcine to reach 2%;

reducing the calcine under the conditions that the reduction temperature is 800-950 ℃, the reduction time is four hours and the carbon ratio is 30 percent to obtain a reduction lump material; the reduction reaction formula is as follows: fe2O3+ C → Fe + CO2 and CaSO4 → CaO + SO 3;

crushing the reducing lump material by using a jaw crusher to obtain a granularity reducing lump material;

step (5) the reduction lump material and carbon monoxide are subjected to synthetic reaction in a synthetic kettle to generate iron pentacarbonyl and synthetic residues, wherein the iron pentacarbonyl is used for producing micron-sized carbonyl iron powder with high added value; the rare earth elements in the synthetic residue are enriched, and the grade is improved from 30% to 70%.

Specifically, the oxidizing roasting temperature of the neodymium iron boron waste in the rotary roasting kiln in the step (1) is 600-: the reduction rate of iron reaches more than 95 percent, and the rare earth elements are not reduced basically; secondly, sulfate radicals in the sulfate are decomposed to generate sulfur trioxide and the sulfur trioxide is absorbed by reduced iron, the iron contains 0.2-0.6% of sulfur element, the speed of the oxo reaction can be greatly improved, the granularity of the reduced blocks in the step (4) is less than 30mm, and the synthetic reaction is carried out in the synthetic kettle in the step (5) under the condition of 11.0-30.0 MPa; in the steps, the extraction rate of iron is more than 90%, the grade of rare earth elements in the synthetic residue is enriched to be close to 70%, and the synthetic residue is used as a high-grade neodymium iron boron raw material for external treatment;

typical compositions of neodymium iron boron waste materials before and after treatment by the method are as follows:

	Nd	Fe	B	Al
					typical composition of neodymium iron boron waste	33.8%	64.7%	1%	0.5%
Typical components of neodymium iron boron waste treated by the method	67.94%	12.36%	2.01%	1.01%

The invention comprises the following steps: performing oxidizing roasting on the neodymium iron boron waste in a rotary roasting kiln at the temperature of 600-800 ℃ to obtain corresponding mixed oxide, grinding the mixed oxide to 200 meshes, and performing roasting process: nd + O2 → Nd2O3 and Fe + O2 → Fe2O3 treats the calcine with saturated sulfate, calcium sulfate, magnesium sulfate, nickel sulfate and other solutions to ensure that the sulfate content in the calcine reaches 2 percent, and the calcine is reduced under the conditions that the reduction temperature is 800-950 ℃, the reduction time is four hours and the carbon ratio is 30 percent to obtain a reduction lump material, wherein the reduction process comprises the following steps: fe2O3+ C → Fe + CO2 and CaSO4 → CaO + SO3, which serves two purposes: selective reduction: the reduction rate of iron reaches more than 95%, rare earth elements are not reduced basically, sulfate radicals in sulfate are decomposed to generate sulfur trioxide and are absorbed by reduced iron, the iron contains 0.2-0.6% of sulfur elements, the speed of the oxo-synthesis reaction can be greatly improved, a jaw crusher is used for crushing reduction lump materials to obtain reduction lump materials with the granularity of less than 30mm, the reduction lump materials and carbon monoxide are subjected to synthetic reaction in a synthesis kettle under the condition of 11.0-30.0MPa to generate iron pentacarbonyl and synthesis residues, and the iron pentacarbonyl is used for producing micron-sized carbonyl iron powder with high added value; the rare earth elements in the synthetic residue are enriched, the grade is improved from 30% to 70%, the extraction rate of iron in the steps is up to more than 90%, the grade of the rare earth elements in the synthetic residue is enriched to be close to 70%, and the rare earth elements are used as high-grade neodymium iron boron raw materials for external treatment.

While there have been shown and described the fundamental principles and essential features of the invention and advantages thereof, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof; the present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.