阅读说明：本技术 一种氧化镝纳米粉体的微波煅烧制备方法 (Microwave calcination preparation method of dysprosium oxide nano powder ) 是由 黄志民 黄慨 顾传君 冼学权 黄绍权 黄华林 于 2020-04-24 设计创作，主要内容包括：本发明公开了一种氧化镝纳米粉体的微波煅烧制备方法,包括如下步骤,(1)表面处理：取氯化镝溶液,调节PH呈碱性,加入氯化镝溶液体积的5-20％的表面助剂混合搅拌均匀得到第一溶液；(2)草沉反应：于搅拌条件下,在第一溶液中按体积比1.0-1.6倍滴加草酸溶液；(3)陈化：反应结束后静置陈化；(4)纯化：用纯水洗涤过滤得到的沉淀,干燥,得到固体草酸镝前驱体；(5)微波煅烧：将固体草酸镝前驱体放入微波反应器中,利用微波加热煅烧,得到氧化镝纳米粉体。本发明在制备的过程中加入了表面助剂,同时采用微波加热煅烧的技术,使得制备得到的氧化镝纳米粉体颗粒细致,均匀,比表面积大。(The invention discloses a microwave calcination preparation method of dysprosium oxide nano powder, which comprises the following steps of (1) surface treatment: taking a dysprosium chloride solution, adjusting the pH value to be alkaline, adding a surface additive accounting for 5-20% of the volume of the dysprosium chloride solution, and mixing and stirring uniformly to obtain a first solution; (2) and (3) carrying out a grass precipitation reaction: under the condition of stirring, dripping oxalic acid solution into the first solution according to the volume ratio of 1.0-1.6 times; (3) aging: standing and aging after the reaction is finished; (4) and (3) purification: washing the precipitate obtained by filtering with pure water, and drying to obtain a solid dysprosium oxalate precursor; (5) microwave calcination: and putting the solid dysprosium oxalate precursor into a microwave reactor, and heating and calcining by using microwaves to obtain dysprosium oxide nano powder. In the preparation process, the surface auxiliary agent is added, and the microwave heating calcination technology is adopted, so that the dysprosium oxide nano-powder prepared is fine and uniform in particles and large in specific surface area.)

1. A microwave calcination preparation method of dysprosium oxide nano powder is characterized in that: comprises the following steps of (a) carrying out,

(1) surface treatment: taking a dysprosium chloride solution, adjusting the pH value of the dysprosium chloride solution to be alkaline, adding a surface auxiliary agent accounting for 5-20% of the volume of the dysprosium chloride solution, and uniformly mixing and stirring to obtain a first solution;

(2) and (3) carrying out a grass precipitation reaction: under the condition of stirring, dripping oxalic acid solution into the first solution according to the volume ratio of 1.0-1.6 times;

(3) aging: standing and aging after the reaction is finished;

(4) and (3) purification: washing the precipitate obtained by filtering with pure water, and drying to obtain a solid dysprosium oxalate precursor;

(5) microwave calcination: and putting the solid dysprosium oxalate precursor into a microwave reactor, and heating and calcining by using microwaves to obtain dysprosium oxide nano powder.

2. The microwave calcination preparation method of dysprosium oxide nanopowder according to claim 1, characterized in that: the concentration of the dysprosium chloride solution is 1.5-2.0 mol/L.

3. The microwave calcination preparation method of dysprosium oxide nanopowder according to claim 1, characterized in that: the surface auxiliary agent is any one of stearic acid, sodium dodecyl benzene sulfonate and polyethylene glycol.

4. The microwave calcination preparation method of dysprosium oxide nanopowder according to claim 1, characterized in that: the Chinese herbal precipitation reaction in the step (2) is carried out at the temperature of 50-70 ℃.

5. The microwave calcination preparation method of dysprosium oxide nanopowder according to claim 1, characterized in that: the aging time in the step (3) is 5-10 hours.

6. The microwave calcination preparation method of dysprosium oxide nanopowder according to claim 1, characterized in that: the microwave heating calcination frequency in the step (5) is 915 +/-50 MHz or 2450 +/-50 MHz, the microwave power is 1-10kw, and the microwave output mode comprises two modes of continuous waves and pulse waves or two combination modes of the continuous waves and the pulse waves.

7. The microwave calcination preparation method of dysprosium oxide nanopowder according to claim 1, characterized in that: the microwave heating calcination time is 1-3 hours.

8. The microwave calcination preparation method of dysprosium oxide nanopowder according to claim 1, characterized in that: the temperature of the microwave heating calcination is 800-1100 ℃.

Technical Field

The invention belongs to the field of rare earth, and particularly relates to a microwave calcination preparation method of dysprosium oxide nano powder.

Background

Dysprosium is used as a raw material for preparing metal dysprosium, as an additive for glass and neodymium iron boron permanent magnets, and is also used in metal halogen lamps, magneto-optical memory materials, yttrium iron or yttrium aluminum garnet and atomic energy industries. Dysprosium oxide can also be used as an additive for neodymium-iron-boron permanent magnets, and the coercive force of such magnets can be improved by adding about 2 to 3% of dysprosium to the magnets, and although the amount of dysprosium required has not been large in the past, it becomes an essential additive element with the increase in demand for neodymium-iron-boron magnets, and the grade must be about 95 to 99.9%, and the demand is rapidly increasing. Dysprosium oxide is also used as a raw material for preparing metal dysprosium, as an additive for glass and neodymium iron boron permanent magnets, and is also used in metal halogen lamps, magneto-optical memory materials, yttrium iron or yttrium aluminum garnet and atomic energy industries.

At present, a high-temperature solid phase method is mostly adopted for preparing dysprosium oxide, the particle size of the prepared dysprosium oxide powder is larger and can be reduced to 1-2 mu m between 3-10 mu m through strict requirements on process conditions, wherein the main reason is that agglomeration phenomenon occurs due to nonuniform heating in the high-temperature heating and firing process, and meanwhile, when a precursor is prepared, the finer precursor has a higher surface, a stronger agglomeration tendency is generated, and the nanometer powder is difficult to prepare. Dysprosium oxide with large specific surface area is an indispensable material for rapid development of high-tech materials to breadth and depth, the application and the dosage of the dysprosium oxide are rapidly increased, and the dysprosium oxide has great market potential.

Disclosure of Invention

The invention aims to provide a method for preparing dysprosium oxide nano powder by a microwave heating technology, and the prepared powder has uniform particle size, small particle size and large specific surface area.

The purpose of the invention is realized by the following technical scheme:

a microwave calcination preparation method of dysprosium oxide nano-powder comprises the following steps,

(1) surface treatment: taking a dysprosium chloride solution, adjusting the pH value of the dysprosium chloride solution to be alkaline, adding a surface auxiliary agent accounting for 5-20% of the volume of the dysprosium chloride solution, and uniformly mixing and stirring to obtain a first solution;

(2) and (3) carrying out a grass precipitation reaction: under the condition of stirring, dripping oxalic acid solution into the first solution according to the volume ratio of 1.0-1.6 times;

(3) aging: standing and aging after the reaction is finished;

(4) and (3) purification: washing the precipitate obtained by filtering with pure water, and drying to obtain a solid dysprosium oxalate precursor;

(5) microwave calcination: and putting the solid dysprosium oxalate precursor into a microwave reactor, and heating and calcining by using microwaves to obtain dysprosium oxide nano powder.

Preferably, the concentration of the dysprosium chloride solution is 1.5-2.0 mol/L.

Preferably, the surface auxiliary agent is any one of stearic acid, sodium dodecyl benzene sulfonate and polyethylene glycol.

Preferably, the herbal precipitation reaction in the step (2) is carried out at 50-70 ℃. At the temperature, the deposition of dysprosium oxalate is facilitated, and the recovery rate of dysprosium is higher than 99%.

Preferably, the aging time in the step (3) is 5 to 10 hours.

Preferably, in the step (5), the frequency of the microwave heating calcination is 915 +/-50 MHz or 2450 +/-50 MHz, the power of the microwave is 1-10kw, and the microwave output mode comprises two modes of continuous waves and pulse waves or the combination of the two modes.

Preferably, the microwave heating calcination time is 1-3 hours. Through microwave heating calcination, the heat conduction is uniform, the temperature rise inside and outside the crystal grains is consistent, and the crystal grains can be quickly converted in a short time, so that the calcination time is greatly reduced.

Preferably, the temperature for microwave heating calcination is 800-1100 ℃.

The invention has the following beneficial effects:

1. in the preparation process, the surface auxiliary agent is added, a layer of diaphragm is generated on the surface of the generated crystal grain, the surface energy of the diaphragm is reduced, the crystal grain is prevented from growing in the precipitation process, and the agglomeration of the crystal grain is prevented; the nano powder particles prepared by the aid are finer and more uniform in size.

2. The invention adopts the microwave heating technology, and in the heating and calcining process, the surface and the interior of the crystal grains are simultaneously heated, the heating is rapid, the heat conduction is uniform, the heating rate and the time are controllable, so that after the surface auxiliary agent and the oxalic acid reach the decomposition and combustion temperature, the decomposed gas is rapidly expanded to play a certain explosion role, and the prepared product is more delicate and has higher specific surface area.

3. The purity of the dysprosium oxide prepared by the method is more than 99.9 percent, the recovery rate of the dysprosium is more than 99 percent, and resources are fully utilized.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the following will clearly and completely describe the technical solutions in the present application with reference to the embodiments, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and all other embodiments obtained by a person of ordinary skill in the art without making creative efforts based on the embodiments in the present application shall fall within the protection scope of the present application.