CN103466649A - Cleaner production method for preparing superfine boride powder through self-propagating metallurgy method - Google Patents

Abstract

A clean production method for preparing superfine boride powder by self-propagating metallurgy, which is carried out according to the following steps: (1) After mixing metal oxide, boron oxide and magnesium powder, ball milling, pressing into a billet, and putting it into a self-propagating reaction A self-propagating reaction is induced in a furnace; naturally cooled to room temperature to obtain a crude product; (2) The crude product is leached with hydrochloric acid after crushing, and the solid phase and leachate are obtained by filtration; (3) The solid phase obtained by leaching is washed and dried to produce Ultra-fine boride powder; (4) Spray pyrolysis is used to treat the leaching solution; nano-sized magnesium oxide and pyrolysis tail gas are obtained; hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The invention adopts the method of self-propagating metallurgy to produce ultra-fine powder, which has the characteristics of low raw material cost, low energy consumption, simple operation, low requirements on process conditions, etc., and the product has high purity, small particle size and high powder activity.

Description

A clean production method for preparing ultrafine boride powder by self-propagating metallurgy

technical field

The invention belongs to the technical field of metallurgy, in particular to a clean production method for preparing superfine boride powder by self-propagating metallurgy.

Background technique

Ultrafine powder preparation technology is accompanied by modern high-tech and new material industries, such as microelectronics and information technology, high-tech ceramics and refractory materials, polymer-based composite materials, biochemical industry, aerospace, new energy, etc., as well as traditional industrial technologies A new engineering technology developed by progress and comprehensive utilization of resources and deep processing is an emerging comprehensive technical science, which is of great significance to the development of modern high-tech industries.

The preparation technology of ultrafine powder can be divided into gas phase method, liquid phase method and solid phase method from a large range. At present, the pulverization method is the most used in industry. The preparation of ultrafine powder by the above method usually has high energy consumption and high cost. , complex process and other shortcomings. Compared with the above production methods, the production of refractory metal powder, amorphous boron powder or boride ceramic powder and other ultrafine powders by self-propagating metallurgy has the advantages of low raw material cost, low energy consumption, simple operation, and low requirements on process conditions, etc. Features, and the product has high purity, small particle size, and high powder activity. Northeastern University combined the self-propagating high-temperature synthesis process and metallurgical leaching process, and invented a new technology for the preparation of ultra-fine powder by self-propagating metallurgy (patent numbers are ZL200510047297.8, ZL200510047308.2, ZL201010233471.9, ZL201010233478.0, ZL200810011972.5), that is, the oxide and reducing agent magnesium powder and other raw materials are mixed, pressed into a blank and placed in a self-propagating reaction furnace, and the self-propagating reaction is induced by means of local ignition or constant temperature detonation, and the product is dispersed in a spongy shape after cooling. The crude product in the magnesium oxide matrix is directly leached with dilute acid as the leaching agent at room temperature, and the ultrafine powder is obtained by filtration and separation. Due to the introduction of the acid leaching process, a large amount of acidic magnesium-containing waste liquid is produced during the leaching process. .

Contents of the invention

Aiming at the above-mentioned problems in the process of preparing ultra-fine powder by self-propagating metallurgy, the present invention provides a clean production method for preparing ultra-fine boride powder by self-propagating metallurgy, that is, using hydrochloric acid as the leaching agent to leaching the boride obtained by self-propagating high-temperature synthesis For the crude product, remove the magnesium oxide, filter and separate to obtain ultra-fine powder and magnesium chloride solution, and then directly spray and thermally decompose the magnesium chloride solution to obtain nano-sized magnesium oxide powder, and at the same time obtain hydrogen chloride gas, which can be returned to leaching after absorption The process is recycled to realize the clean production of the process.

The self-propagating metallurgical method of the present invention prepares the clean production method of ultra-fine boride powder to carry out as follows:

1. Mix metal oxide, boron oxide and magnesium powder and ball mill to a particle size of ≤0.5 μm, then press it into a billet, and put it into a self-propagating reaction furnace to initiate a self-propagating reaction; the metal oxides are ytterbium oxide and cerium oxide , zirconia, lanthanum oxide, neodymium oxide, samarium oxide, calcium oxide or titanium oxide;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the metal boride in the crude product is dispersed in the spongy magnesium oxide matrix;

2. After crushing the crude product, separate the magnesium oxide in it by leaching with hydrochloric acid; the concentration of hydrochloric acid used for leaching is 1~5mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is (4~20): 1ml/g , leaching adopts the method of normal temperature leaching or high temperature leaching under airtight conditions; when leaching at normal temperature, the leaching temperature is 25~90°C, and the leaching time is 10~40h; when leaching at high temperature, the leaching temperature is 100~150°C, 30~180min; after leaching, filter to obtain solid phase and leachate;

3. Wash the solid phase obtained by leaching to remove impurities, then dry to remove water, and make ultrafine boride powder with a weight purity ≥ 99%;

4. The leachate is treated by spray pyrolysis; the spray pyrolysis is to atomize and spray the leachate into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.13~0.6MPa, and then pyrolyze to obtain nano-sized magnesium oxide and Pyrolysis tail gas; the hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling; the pyrolysis temperature in the high-temperature pyrolysis furnace is 200~700°C, and the pyrolysis time is 0.5~60min.

In the above method, the pressure when pressing into a billet is 40~70MPa.

In the above method, when the metal oxide is ytterbium oxide, the mixing ratio is ytterbium oxide:boron oxide:magnesium powder=100: (100~115):(135~160), when the metal oxide is cerium oxide , the mixing ratio is cerium oxide by mass ratio: boron oxide: magnesium powder = 100: (110~130): (160~185), when the metal oxide is zirconia, the mixing ratio is zirconia by mass ratio: boron oxide : Magnesium powder=100: (60~65): (105~122), when the metal oxide is lanthanum oxide, the mixing ratio is lanthanum oxide by mass ratio: Boron oxide: magnesium powder=100: (120~135): (160~185), when the metal oxide is neodymium oxide, the mixing ratio is neodymium oxide by mass ratio: boron oxide: magnesium powder = 100: (118~132): (160~185), when the metal oxide is oxide For samarium, the mixing ratio is samarium oxide by mass ratio: boron oxide: magnesium powder = 100: (115~127): (155~180), when the metal oxide is calcium oxide, the mixing ratio is calcium oxide by mass ratio: Boron oxide: magnesium powder = 100: (335~390): (450~515), when the metal oxide is titanium oxide, the mixing ratio is titanium oxide by mass ratio: boron oxide: magnesium powder = 100: (90~95 ): (155~180).

The general formula of the above-mentioned self-propagating reaction is as follows:

MeO _x +y/2B ₂ O ₃ +(x+3y/2)Mg=MeB _y +(x+3y/2)MgO+△H

Wherein Me is Y, Ce, Zr, La, Nd, Sm, Ca or Ti, and △H represents the heat of reaction released during the self-propagating reaction;

The leaching process reaction in the above method is as follows:

MgO+2HCl=MgCl ₂ +H ₂ O;

The reaction of thermal decomposition process in the above-mentioned method is as follows:

MgCl ₂ +H ₂ O=MgO+2HCl.

The above-mentioned ultrafine boride powders are ytterbium boride powder with particle size ≤300nm, cerium boride powder with particle size ≤400nm, zirconium boride powder with particle size ≤400nm, lanthanum boride powder with particle size ≤0.5 μm neodymium boride powder, samarium boride powder with particle size ≤0.5μm, calcium boride powder with particle size 0.8~2.5μm or titanium boride powder with particle size ≤0.5μm.

The mass concentration of magnesium chloride in the above leach solution is 50-300 g/L.

The particle size of the above-mentioned nano-sized magnesium oxide is 80~390 nm.

The concentration of hydrochloric acid formed after the absorption of the above-mentioned hydrogen chloride is 1-5 mol/L.

In the above method, the self-propagating reaction is divided into two types: direct detonation and constant temperature detonation; direct detonation is to directly heat the billet under the air atmosphere until the self-propagating reaction occurs, at this time a dazzling flame will be formed, and a large amount of smoke will be volatilized. , the temperature of the reaction system rises rapidly; constant temperature initiation refers to heating the billet under the air atmosphere, and the temperature is controlled between 720~950°C until the self-propagating reaction occurs. At this time, a dazzling flame will be formed and a large number of The smoke evaporates, and the temperature of the reaction system rises rapidly.

Since the self-propagating reaction occurs in an open air atmosphere, and the temperature of the self-propagating reaction is very high, the amount of metal magnesium gasifies during the reaction process, which will cause a large amount of volatilization loss of Mg, so that Mg will be insufficient; in order to make up for the volatilization loss of Mg , in the present invention, the amount of metal magnesium is 5-25% higher than the theoretical requirement of the reaction during batching; in order to make the operation of the self-propagating reaction easier, the self-propagating reaction can also be initiated by a local ignition method.

Compared with the traditional ultrafine powder preparation technology, the characteristics and beneficial effects of the present invention are:

(1) Self-propagating metallurgy is used to produce ultra-fine powder, which has the characteristics of low raw material cost, low energy consumption, simple operation, and low requirements on process conditions, and the product has high purity, small particle size, and high powder activity;

(2) The magnesium chloride solution is treated by spray thermal decomposition, the reaction efficiency is high, and nano-scale magnesium oxide products can be obtained, which improves the added value of the product;

(3) The acid and water generated in the production process can be recycled through the thermal decomposition process, realizing the waste-free cleaning of the whole process

Production.

Description of drawings

Fig. 1 is a schematic flow chart of a clean production method for preparing ultra-fine boride powder by self-propagating metallurgy of the present invention.

Detailed ways

The magnesium powder, boron oxide, ytterbium oxide, cerium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, samarium oxide, calcium oxide, and titanium oxide used in the examples of the present invention are industrial grade products with a particle size of ≤0.5 mm.

The self-propagating reaction furnace adopted in the embodiment of the present invention is the self-propagating reaction furnace disclosed in the patent "ZL200510047308.2". .

The time of the self-propagating reaction in the embodiment of the present invention is 5-90s.

Washing in the embodiment of the present invention is to filter and wash the solid phase with water, and the obtained acidic washing water is used to supplement the lost water in the hydrochloric acid leaching process.

In the embodiment of the present invention, the drying time is at least 24 hours.

The high temperature pyrolysis furnace used in the embodiment of the present invention is a tube furnace.

In the embodiment of the present invention, when pressing into a blank, the pressed blank is cylindrical with a diameter of 5-10 cm.

The equipment used for ball milling in the embodiments of the present invention is a high-energy ball mill.

Example 1

Mix ytterbium oxide, boron oxide and magnesium powder and ball mill to a particle size of ≤0.5 μm, then press it into a billet, put it into a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is ytterbium oxide:boron oxide:magnesium powder= 100:100:135; The pressure when pressed into a billet is 40MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the ytterbium boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After the crude product is crushed, the magnesia in it is separated by hydrochloric acid leaching; the concentration of hydrochloric acid used in leaching is 1mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 4:1ml/g, and the leaching adopts normal temperature leaching. The leaching temperature is 25°C and the leaching time is 40h; after leaching, the solid phase and leachate are obtained by filtration; the mass concentration of magnesium chloride in the leachate is 50g/L;

The solid phase obtained by leaching is washed to remove impurities, and then dried to remove water to produce ultra-fine ytterbium boride powder with a weight purity ≥ 99%, with a particle size of 150-300nm;

The leachate is treated by spray pyrolysis; the spray pyrolysis is to spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.13MPa, and then pyrolyze to obtain nano-sized magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 80~150 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 1mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 500°C, and the pyrolysis time is 5min.

Example 2

Method is the same as embodiment 1, the difference is:

(1) The mixing ratio is ytterbium oxide: boron oxide: magnesium powder = 100: 115: 160 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 3mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 8:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 50°C, and the leaching time is 20h; The mass concentration is 150g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.25MPa. The particle size of nano-sized magnesium oxide is 100-220 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 3mol/L; the pyrolysis temperature is 700°C and the pyrolysis time is 0.5min.

Example 3

Method is with embodiment 1, and difference is:

(1) The mixing ratio is ytterbium oxide: boron oxide: magnesium powder = 100: 109: 142 by mass ratio; the pressure when pressing into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 5mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 20:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 90°C, and the leaching time is 10h; the magnesium chloride in the leaching solution The mass concentration is 300g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.6MPa. The particle size of nano-sized magnesium oxide is 320~390 nm, and the hydrogen chloride is absorbed. The concentration of hydrochloric acid is 5mol/L; the pyrolysis temperature is 200°C and the pyrolysis time is 60min.

Example 4

Cerium oxide, boron oxide and magnesium powder are mixed and ball-milled to a particle size of ≤0.5 μm, then pressed into a billet and placed in a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is cerium oxide:boron oxide:magnesium powder= 100:110:160; the pressure when pressed into a billet is 40MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the cerium boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After the crude product is crushed, the magnesia in it is separated by hydrochloric acid leaching; the concentration of hydrochloric acid used in leaching is 1mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 4:1ml/g, and the leaching adopts normal temperature leaching. The leaching temperature is 25°C and the leaching time is 40h; after leaching, the solid phase and leachate are obtained by filtration; the mass concentration of magnesium chloride in the leachate is 50g/L;

Wash the solid phase obtained by leaching to remove impurities, then dry to remove water, and make superfine cerium boride powder with a weight purity ≥ 99%, with a particle size of 150-400nm;

The leachate is treated by spray pyrolysis; the spray pyrolysis is to spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.13MPa, and then pyrolyze to obtain nano-sized magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 80~150 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 1mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 500°C, and the pyrolysis time is 5min.

Example 5

Method is the same as embodiment 1, the difference is:

(1) The mixing ratio is cerium oxide: boron oxide: magnesium powder = 100:130:185 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 3mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 8:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 50°C, and the leaching time is 20h; The mass concentration is 150g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.25MPa. The particle size of nano-sized magnesium oxide is 100-220 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 3mol/L; the pyrolysis temperature is 700°C and the pyrolysis time is 0.5min.

Example 6

Method is with embodiment 1, and difference is:

(1) The mixing ratio is cerium oxide: boron oxide: magnesium powder = 100:120:175 by mass ratio; the pressure when pressing into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 5mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 20:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 90°C, and the leaching time is 10h; the magnesium chloride in the leaching solution The mass concentration is 300g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.6MPa. The particle size of nano-sized magnesium oxide is 320~390 nm, and the hydrogen chloride is absorbed. The concentration of hydrochloric acid is 5mol/L; the pyrolysis temperature is 200°C and the pyrolysis time is 60min.

Example 7

Mix zirconia, boria and magnesium powder and ball mill to a particle size of ≤0.5 μm, then press it into a billet, put it into a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is zirconia:boria:magnesium powder= 100: 60:105; the pressure when pressed into a billet is 70MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the zirconium boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After crushing the crude product, separate the magnesia in it by leaching with hydrochloric acid; the concentration of hydrochloric acid used for leaching is 4mol/L; The way of leaching, the leaching temperature is 100~150℃, and the leaching time is 180min; after leaching, filter to obtain the solid phase and leachate; the mass concentration of magnesium chloride in the leachate is 60g/L;

Wash the solid phase obtained by leaching to remove impurities, then dry to remove water, and make ultrafine zirconium boride powder with a weight purity ≥ 99%, with a particle size of 200-400 nm;

Spray pyrolysis is used to treat the leachate; spray pyrolysis is to atomize and spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.15MPa, and then pyrolyze to obtain nano-sized magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 280~360 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 4mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 300°C, and the pyrolysis time is 40min.

Example 8

Method is with embodiment 1, and difference is:

(1) The mixing ratio is zirconia: boron oxide: magnesium powder = 100: 65: 122 by mass ratio; the pressure when pressing into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 2mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 10:1ml/g, and the leaching method is high-temperature leaching under airtight conditions. The leaching temperature is 100-150°C and the leaching time is 90min; the mass concentration of magnesium chloride in the leaching solution is 200g/L;

(3) Spray pyrolysis is to atomize and spray the leaching solution into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.4 MPa. The particle size of nano-sized magnesium oxide is 180-300 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 2mol/L; the pyrolysis temperature is 400°C and the pyrolysis time is 30min.

Example 9

Method is the same as embodiment 1, the difference is:

(1) The mixing ratio is zirconia: boron oxide: magnesium powder = 100: 63: 110 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 5mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 18:1ml/g, and the leaching method is high-temperature leaching under airtight conditions, the leaching temperature is 100~150°C, and the leaching time is 30min; the mass concentration of magnesium chloride in the leaching solution is 220g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.5 MPa. The particle size of nano-sized magnesium oxide is 180-250 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 5mol/L; the pyrolysis temperature is 300°C and the pyrolysis time is 10min. the

Example 10

After mixing lanthanum oxide, boron oxide and magnesium powder, ball milling to a particle size of ≤0.5 μm, and then pressing it into a billet, putting it into a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is lanthanum oxide:boron oxide:magnesium powder= 100:120:160; the pressure when pressed into a billet is 40MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the lanthanum boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After the crude product is crushed, the magnesia in it is separated by leaching with hydrochloric acid; the concentration of hydrochloric acid used for leaching is 4mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 6:1ml/g, and the leaching is carried out at room temperature. The leaching temperature is 90°C and the leaching time is 10h; after leaching, the solid phase and leachate are obtained by filtration; the mass concentration of magnesium chloride in the leachate is 220g/L;

The solid-phase washing obtained by leaching removes impurities, and then drying to remove water to produce ultra-fine lanthanum boride powder with a weight purity ≥ 99%, with a particle size of 0.8-3.0 μm;

The leachate is treated by spray pyrolysis; the spray pyrolysis is to spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.2MPa, and then pyrolyze to obtain nano-sized magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 110~220 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 4mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 200°C, and the pyrolysis time is 1min.

Example 11

Method is with embodiment 1, and difference is:

(1) The mixing ratio is lanthanum oxide: boron oxide: magnesium powder = 100: 135: 185 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 3mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 12:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 25°C, and the leaching time is 40h; The mass concentration is 105g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.3MPa. The particle size of nano-sized magnesium oxide is 280~390 nm, and the hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 3mol/L; the pyrolysis temperature is 700°C and the pyrolysis time is 50min.

Example 12

Method is the same as embodiment 1, the difference is:

(1) The mixing ratio is lanthanum oxide: boron oxide: magnesium powder = 100:130:170 by mass ratio; the pressure when pressing into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 2mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 20:1ml/g, and the leaching method is leaching at room temperature, the leaching temperature is 80°C, and the leaching time is 15h; the magnesium chloride in the leaching solution The mass concentration is 120g/L;

(3) Spray pyrolysis is to atomize and spray the leaching solution into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.4 MPa. The particle size of nano-sized magnesium oxide is 80-120 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 2mol/L; the pyrolysis temperature is 200°C and the pyrolysis time is 60min.

Example 13

Mix neodymium oxide, boron oxide and magnesium powder and ball mill to a particle size of ≤0.5 μm, then press it into a billet, put it into a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is neodymium oxide:boron oxide:magnesium powder= 100:118:160; The pressure when pressed into a billet is 70MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the neodymium boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After crushing the crude product, separate the magnesia in it by leaching with hydrochloric acid; the concentration of hydrochloric acid used in leaching is 1mol/L; The leaching method The leaching temperature is 100~150°C, and the leaching time is 100min; after leaching, filter to obtain the solid phase and leachate; the mass concentration of magnesium chloride in the leachate is 50g/L;

The solid phase obtained by leaching is washed to remove impurities, and then dried to remove water to produce ultra-fine neodymium boride powder with a weight purity ≥ 99%, with a particle size of 0.2-0.5 μm;

The leachate is treated by spray pyrolysis; the spray pyrolysis is to spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.5MPa, and then pyrolyze to obtain nano-sized magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 90~160 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 1mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 300°C, and the pyrolysis time is 40min.

Example 14

Method is with embodiment 1, and difference is:

(1) The mixing ratio is neodymium oxide: boron oxide: magnesium powder = 100:132:185 by mass ratio; the pressure when pressed into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 2mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 10:1ml/g, and the leaching method is high-temperature leaching under airtight conditions. The leaching temperature is 100-150°C and the leaching time is 60min; the mass concentration of magnesium chloride in the leach solution is 120g/L;

(3) Spray pyrolysis is to atomize and spray the leaching solution into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.6 MPa. The particle size of nano-sized magnesium oxide is 120-230 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 2mol/L; the pyrolysis temperature is 400°C and the pyrolysis time is 20min.

Example 15

Method is with embodiment 1, and difference is:

(1) The mixing ratio is neodymium oxide: boron oxide: magnesium powder = 100:122:171 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 3mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 20:1ml/g, and the leaching adopts the method of high-temperature leaching under airtight conditions, the leaching temperature is 100~150°C, and the leaching time is 150min; the mass concentration of magnesium chloride in the leach solution is 180g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.18 MPa. The particle size of nano-sized magnesium oxide is 180-290 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 3mol/L; the pyrolysis temperature is 500°C and the pyrolysis time is 10min.

Example 16

Mix samarium oxide, boron oxide and magnesium powder and ball mill to a particle size of ≤0.5 μm, then press it into a billet, put it into a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is samarium oxide:boron oxide:magnesium powder= 100:115:155; The pressure when pressed into a billet is 40MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the samarium boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After the crude product is crushed, the magnesia in it is separated by leaching with hydrochloric acid; the concentration of hydrochloric acid used in leaching is 4mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 18:1ml/g, and the leaching is carried out at room temperature. The leaching temperature is 25°C and the leaching time is 40h; after leaching, the solid phase and leachate are obtained by filtration; the mass concentration of magnesium chloride in the leachate is 210g/L;

Wash the solid phase obtained by leaching to remove impurities, then dry to remove water, and make superfine samarium boride powder with a weight purity ≥ 99%, with a particle size of 0.35~0.5μm;

The leachate is treated by spray pyrolysis; the spray pyrolysis is to spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.24MPa, and then pyrolyze to obtain nano-scale magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 200~300 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 4mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 600°C, and the pyrolysis time is 50min.

Example 17

Method is the same as embodiment 1, the difference is:

(1) The mixing ratio is samarium oxide: boron oxide: magnesium powder = 100:127:180 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 5mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 16:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 90°C, and the leaching time is 10h; the magnesium chloride in the leaching solution The mass concentration is 240g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.35MPa. The particle size of nano-sized magnesium oxide is 200-290 nm, and the hydrogen chloride is absorbed. The concentration of hydrochloric acid is 5mol/L; the pyrolysis temperature is 700°C and the pyrolysis time is 0.5min.

Example 18

Method is the same as embodiment 1, the difference is:

(1) The mixing ratio is samarium oxide: boron oxide: magnesium powder = 100:123:169 by mass ratio; the pressure when pressing into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 5mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 10:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 30°C, and the leaching time is 30h; the magnesium chloride in the leaching solution The mass concentration is 150g/L;

(3) Spray pyrolysis is to atomize and spray the leaching solution into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.48 MPa. The particle size of nano-sized magnesium oxide is 80-160 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 5mol/L; the pyrolysis temperature is 700°C and the pyrolysis time is 1min.

Example 19

Calcium oxide, boron oxide and magnesium powder are mixed and ball-milled to a particle size of ≤0.5 μm, then pressed into a billet and placed in a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is calcium oxide: boron oxide: magnesium powder = 100:335:450; The pressure when pressed into a billet is 70MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the calcium boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After crushing the crude product, the magnesia in it is separated by hydrochloric acid leaching; the concentration of hydrochloric acid used for leaching is 4mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 6:1ml/g, and the leaching is carried out at high temperature under airtight conditions. The way of leaching, the leaching temperature is 100~150℃, and the leaching time is 120min; after leaching, filter to obtain the solid phase and leaching solution; the mass concentration of magnesium chloride in the leaching solution is 80g/L;

The solid phase obtained by leaching is washed to remove impurities, and then dried to remove water to produce ultrafine calcium boride powder with a weight purity ≥ 99%, with a particle size of 0.8-2.5 μm;

The leachate is treated by spray pyrolysis; the spray pyrolysis is to spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.55MPa, and then pyrolyze to obtain nano-sized magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 160~220 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 4mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 600°C, and the pyrolysis time is 5min.

Example 20

Method is the same as embodiment 1, the difference is:

(1) The mixing ratio is calcium oxide: boron oxide: magnesium powder = 100:390:515 by mass ratio; the pressure when pressing into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 3mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 10:1ml/g, and the leaching method is high-temperature leaching under airtight conditions. The leaching temperature is 100-150°C and the leaching time is 90min; the mass concentration of magnesium chloride in the leaching solution is 90g/L;

(3) Spray pyrolysis is to atomize and spray the leaching solution into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.6 MPa. The particle size of nano-sized magnesium oxide is 140-190 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 3mol/L; the pyrolysis temperature is 500°C and the pyrolysis time is 20min.

Example 21

Method is with embodiment 1, and difference is:

(1) The mixing ratio is calcium oxide: boron oxide: magnesium powder = 100:365:495 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 2mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 15:1ml/g, and the leaching method is high-temperature leaching under airtight conditions, the leaching temperature is 100~150°C, and the leaching time is 60min; the mass concentration of magnesium chloride in the leaching solution is 100g/L;

(3) Spray pyrolysis is to atomize and spray the leaching solution into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.13 MPa. The particle size of nano-sized magnesium oxide is 220-300 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 2mol/L; the pyrolysis temperature is 300°C and the pyrolysis time is 40min.

Example 22

Titanium oxide, boron oxide and magnesium powder are mixed and ball-milled to a particle size of ≤0.5 μm, then pressed into a billet and placed in a self-propagating reaction furnace to initiate a self-propagating reaction; the mixing ratio is titanium oxide: boron oxide: magnesium powder = 100:90:155; The pressure when pressed into a billet is 40MPa;

After the self-propagating reaction is finished, the reaction product is naturally cooled to normal temperature to obtain a crude product, and the titanium boride in the crude product is dispersed in the spongy magnesium oxide matrix;

After the crude product is crushed, the magnesia in it is separated by hydrochloric acid leaching; the concentration of hydrochloric acid used in leaching is 1mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 5:1ml/g, and the leaching adopts normal temperature leaching. The leaching temperature is 25°C, and the leaching time is 40h; after leaching, the solid phase and leachate are obtained by filtration; the mass concentration of magnesium chloride in the leachate is 60g/L;

The solid phase obtained by leaching is washed to remove impurities, and then dried to remove water to produce ultra-fine titanium boride powder with a weight purity ≥ 99%, with a particle size of 0.1-0.5 μm;

The leachate is treated by spray pyrolysis; the spray pyrolysis is to atomize and spray the leachate into the high-temperature pyrolysis furnace through the atomization nozzle under the pressure of 0.26MPa, and then pyrolyze to obtain nano-sized magnesium oxide and pyrolysis tail gas; The particle size of nano-sized magnesium oxide is 320~390 nm;

The hydrogen chloride in the pyrolysis tail gas is absorbed to form hydrochloric acid, which is returned to the leaching process for recycling. The concentration of hydrochloric acid formed after the absorption of hydrogen chloride is 1mol/L; the pyrolysis temperature in the high-temperature pyrolysis furnace is 200°C, and the pyrolysis time is 60min.

Example 23

Method is with embodiment 1, and difference is:

(1) The mixing ratio is titanium oxide: boron oxide: magnesium powder = 100: 95: 180 by mass ratio; the pressure when pressing into a billet is 50MPa;

(2) The concentration of hydrochloric acid used in the leaching is 2mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 10:1ml/g, and the leaching method is leaching at room temperature, the leaching temperature is 90°C, and the leaching time is 10h; the magnesium chloride in the leaching solution The mass concentration is 70g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into a high-temperature pyrolysis furnace through an atomizing nozzle under a pressure of 0.45 MPa. The particle size of nano-sized magnesium oxide is 280-340 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 2mol/L; the pyrolysis temperature is 200°C and the pyrolysis time is 60min.

Example 24

Method is with embodiment 1, and difference is:

(1) The mixing ratio is titanium oxide: boron oxide: magnesium powder = 100:92:168 by mass ratio; the pressure when pressing into a billet is 60MPa;

(2) The concentration of hydrochloric acid used in the leaching is 3mol/L; the liquid-solid ratio of hydrochloric acid to the crude product is 20:1ml/g, the leaching method is leaching at room temperature, the leaching temperature is 50°C, and the leaching time is 20h; The mass concentration is 110g/L;

(3) Spray pyrolysis is to atomize and spray the leaching liquid into the high-temperature pyrolysis furnace through the atomizing nozzle under the pressure of 0.6 MPa. The particle size of nano-sized magnesium oxide is 180-280 nm, and hydrogen chloride is formed after absorption. The concentration of hydrochloric acid is 3mol/L; the pyrolysis temperature is 700°C and the pyrolysis time is 0.5min.

Claims (6)

1. the clean preparation method of the standby Superfine Boron compound powder of a self-spreading metallurgical legal system is characterized in that carrying out according to the following steps:

(1) by after metal oxide, boron oxide and the mixing of magnesium powder, being milled to granularity≤0.5 μ m, then be pressed into blank, put into the self-propagating reaction stove and cause self-propagating reaction; Described metal oxide is ytterbium oxide, cerium oxide, zirconium white, lanthanum trioxide, Neodymium trioxide, Samarium trioxide, calcium oxide or titanium oxide;

After self-propagating reaction finishes, reaction product naturally cools to normal temperature, obtains thick product, and the metal boride disperse in thick product is in spongy magnesium oxide matrix;

(2) by thick product after fragmentation, adopt the mode of Leaching in Hydrochloric Acid to separate magnesium oxide wherein; Leaching the concentration of hydrochloric acid adopted is 1 ~ 5mol/L; Hydrochloric acid is (4 ~ 20): 1ml/g with the liquid-solid ratio of thick product, leaches the mode that adopts normal temperature to leach or the mode that high temperature leaches in confined conditions; When normal temperature leaches, extraction temperature is that 25 ~ 90 ℃, extraction time are 10 ~ 40h; When high temperature leaches, extraction temperature is that 100 ~ 150 ℃, extraction time are 30 ~ 180min; Filter after leaching and obtain solid phase and leach liquor;

(3) impurity is removed in the solid phase washing that leaching obtains, then dries removal moisture, makes the Superfine Boron compound powder of weight purity >=99%;

(4) adopt the mode of spraying thermolysis to process leach liquor; The spraying thermolysis is by atomizing nozzle, leach liquor to be carried out to the atomization winding-up in the high temperature pyrolysis stove under the pressure of 0.13 ~ 0.6MPa, then pyrolysis obtains nano level magnesium oxide and pyrolysis tail gas; Hydrogenchloride in pyrolysis tail gas forms hydrochloric acid after absorbing, and returns to leaching process and recycles; Pyrolysis temperature in the high temperature pyrolysis stove is that 200 ~ 700 ℃, pyrolysis time are 0.5 ~ 60min.

2. a kind of self-spreading metallurgical legal system according to claim 1 is for the clean preparation method of Superfine Boron compound powder, it is characterized in that when metal oxide is ytterbium oxide, blending ratio is ytterbium oxide in mass ratio: boron oxide: magnesium powder=100:(100 ~ 115): (135 ~ 160), when oxide compound is cerium oxide, blending ratio is cerium oxide in mass ratio: boron oxide: magnesium powder=100:(110 ~ 130): (160 ~ 185), when oxide compound is zirconium white, blending ratio is zirconium white in mass ratio: boron oxide: magnesium powder=100:(60 ~ 65): (105 ~ 122), when oxide compound is lanthanum trioxide, blending ratio is lanthanum trioxide in mass ratio: boron oxide: magnesium powder=100:(120 ~ 135): (160 ~ 185), when oxide compound is Neodymium trioxide, blending ratio is niobium oxides in mass ratio: boron oxide: magnesium powder=100:(118 ~ 132): (160 ~ 185), when oxide compound is Samarium trioxide, blending ratio is Samarium trioxide in mass ratio: boron oxide: magnesium powder=100:(115 ~ 127): (155 ~ 180), when oxide compound is calcium oxide, blending ratio is calcium oxide in mass ratio: boron oxide: magnesium powder=100:(335 ~ 390): (450 ~ 515), when oxide compound is titanium oxide, blending ratio is titanium oxide in mass ratio: boron oxide: magnesium powder=100:(90 ~ 95): (155 ~ 180).

3. the clean preparation method of the standby Superfine Boron compound powder of a kind of self-spreading metallurgical legal system according to claim 1, is characterized in that the ytterbium boride powder that described Superfine Boron compound powder is granularity≤300nm, the cerium boride powder of granularity≤400nm, the boronation zirconium powder of granularity≤400nm, the lanthanum boride powder of granularity 0.8 ~ 3.0 μ m, the neodymium boride powder of granularity≤0.5 μ m, the samarium boride powder of granularity≤0.5 μ m, the boronation calcium powder of granularity 0.8 ~ 2.5 μ m or the titanium boride powder of granularity≤0.5 μ m.

4. a kind of self-spreading metallurgical legal system according to claim 1 is for the clean preparation method of Superfine Boron compound powder, and the mass concentration that it is characterized in that magnesium chloride in described leach liquor is 50 ~ 300g/L.

5. the clean preparation method of the standby Superfine Boron compound powder of a kind of self-spreading metallurgical legal system according to claim 1, is characterized in that the magnesian granularity of described nano level is 80 ~ 390 nm.

6. the clean preparation method of the standby Superfine Boron compound powder of a kind of self-spreading metallurgical legal system according to claim 1, is characterized in that the concentration of the hydrochloric acid that described hydrogenchloride forms after absorbing is 1 ~ 5mol/L.

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