CN1057068C

CN1057068C - Method for preparing Bi2O3 powder for electronic industry

Info

Publication number: CN1057068C
Application number: CN94111819A
Authority: CN
Inventors: 雷慧绪; 彭少芳
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-07-02
Filing date: 1994-07-02
Publication date: 2000-10-04
Anticipated expiration: 2014-07-02
Also published as: CN1114637A

Abstract

The present invention relates to a method for preparing Bi2O3 powder for electronic industry. The present invention is characterized in that firstly, bismuth (a kind of high-purity electrolytic metal) is adopted as a raw material to prepare bismuth nitrate solution; secondly, the bismuth nitrate solution is hydrolyzed to generate BiONO3; finally, the BiONO3 is converted by NaOH to directly obtain Bi2O3. The technological parameters of the present invention comprise: the bismuth content of the bismuth nitrate solution is more than 200 to 300 g/l, the end pH value of the hydrolysis reaction is from 1.5 to 2.5, the conversion temperature is from 10 to 90 DEG C, and the conversion time is from 10 minutes to 2 hours. The Bi2O3 powder prepared by the present invention is characterized in that the purity is higher than 99.5%, the fisher particle size is smaller than 2 micrometers, the grain size is smaller than 500A, and the Bi2O3 powder is a high-quality doping material for electronic elements.

Description

Used in electronic industry Bi 2O 3The preparation method of powder

The invention belongs to used in electronic industry Bi ₂O ₃The preparation method of powder, this kind Bi ₂O ₃Powder is used for doing ceramic capacitor, the dopant material of the components and parts such as piezo-resistance.

Preparation Bi ₂O ₃Traditional handicraft be bismuth metal to be dissolved in red fuming nitric acid (RFNA) generate bismuth nitrate solution, generate novismuth through hydrolysis again, then novismuth is changed into Bi 600 ℃ of lower calcinings ₂O ₃The Bi of this technology preparation ₂O ₃Granularity about 6 μ m, if when calcining conduct heat bad even can greater than 6 μ m, be unwell to the dopant material of making electronic devices and components.

Provide a kind of Bi in " Hydrolytic preparation of bismuth oxide[" Tsuetn.Met. " 1989,12,37-41 (Russ)] " ₂O ₃The preparation method, the processing step of this method is followed successively by: (1) bismuth nitrate hydrolysis; (2) filter, wash; (3) with hydrolysate BiONO ₃Add carbonate and be converted into (BiO) ₂CO ₃(4) filter, wash; (5) by calcining (BiO) ₂CO ₃Change into Bi ₂O ₃Only reported prepared Bi in this article ₂O ₃Specific area, and whether undeclared its is suitable for doing the dopant material of electronic devices and components.With regard to technology, there is following problem in this method: (1) has increased intermediate product (BiO) ₂CO ₃Namely increased operation, cost is increased; (2) by calcining intermediate product is converted into Bi ₂O ₃The time, wayward Bi ₂O ₃Granularity.

Provide a kind of employing NaOH or KOH to make novismuth directly change into Bi in " Hydrometallurgical method of bismuth oxide production[" Tsuetn.Met. " 1983,10,32-34 (Russ)] " ₂O ₃Method, but its optimum process condition (addition of NaOH is 125～150% of theoretical amount, and 70～90 ℃ of conversion temperatures, liquid-solid ratio are 3～5: 1) the lower Bi that can only obtain purity≤99.4%, Fisher particle size＞2 μ m ₂O ₃Powder.

The objective of the invention is to overcome the deficiency of prior art, a kind of practicable used in electronic industry Bi is provided ₂O ₃The preparation method of powder, this method can not only prepare the Bi that purity height, physical index meet the requirement of electronic devices and components dopant material ₂O ₃Powder, and technology is simple, the energy environmental contamination reduction.

Preparation method provided by the present invention, processing step is followed successively by: the preparation of (1) bismuth nitrate solution; (2) Bismuth trinitrate (Bi (NO ₃) ₃) hydrolysis; (3) filter, wash; (4) hydrolysate bismuthyl nitrate (BiONO ₃) slurrying; (5) hydrolysate bismuthyl nitrate alkali transforms; (6) filter, wash, dry.According to thermodynamics, kinetic theory, in the above-mentioned steps, bismuth nitrate solution preparation, bismuth nitrate hydrolysis, the conversion of hydrolysate novismuth alkali are committed steps, and the choose reasonable of its process conditions is determining Bi ₂O ₃The purity of powder and physical index.Method provided by the present invention has provided the technological parameter of each committed step, and particular content is as follows: bismuth nitrate solution preparation is take highly purified electrolytic metal bismuth and industrial concentrated acid as raw material, bi content in the bismuth nitrate solution for preparing＞200～300g/l; The bismuth nitrate hydrolysis is made hydrolytic reagent with industrial ammonia, and hydrolysis at room temperature carries out, and the endpoint pH of hydrating solution is controlled at 1.5～2.5; It is to add NaOH to make it be converted into Bi in the novismuth slurries that the hydrolysate novismuth transforms ₂O ₃, conversion temperature is 10～90 ℃, and the addition of NaOH is greater than theoretical amount, and concrete quantity determines that according to transform mode and conversion temperature transformation time shortens with the rising of conversion temperature, is 10 minutes～2 hours.

Hydrolysate bismuthyl nitrate alkali transforms this step, can under agitation carry out, and also can carry out under ultrasonic vibration, and for above-mentioned two kinds of transform modes, corresponding optimal processing parameter is combined as:

1. novismuth alkali transforms and under agitation to carry out, and conversion temperature is 70～90 ℃, adopts two step conversion methods, and the addition of NaOH is by the control of pH value, first step conversion, and the pH value is controlled at 9-12 (addition of NaOH be theoretical amount 85～90%), BiONO ₃Major part is converted into Bi ₂O ₃, to filter, slurrying is carried out second step and transformed after the washing, the pH value still is controlled at 9～12 (addition of NaOH be theoretical amount 15～20%).

2. bismuthyl nitrate alkali transforms and carries out under ultrasonic vibration, and the optimal conversion temperature is 40～60 ℃, and the add-on of NaOH is controlled with endpoint pH, and the pH value is 9～12.

3. bismuthyl nitrate alkali transforms and under agitation carries out, and invert point is 10～30 ℃, and the minimum add-on of NaOH is 200% of a theoretical amount.

Compared with prior art, the present invention has the following advantages:

According to method provided by the present invention can prepare purity greater than 99.5%, Fisher particle size is less than 2 μ m, the grain size Bi less than 500 ₂O ₃Powder, therefore, for the Bi of the required relevant art index of the electronic devices and components such as ceramic capacitor, zno varistor ₂O ₃Powder all can prepare.

2. adopt the Bi of the present invention's preparation ₂O ₃Powder is made the electronic component that dopant material is produced, and its electrical property improves a lot, stability and good reliability.

3. directly in liquid phase, prepare Bi ₂O ₃Powder both had been easy to control the granularity of product, can avoid again calcining the pernicious gas that produces when transforming to the pollution of environment, and simplify operation.

Fig. 1 is a process flow sheet of the present invention.

Describe method provided by the present invention in detail below in conjunction with Fig. 1.

Embodiment 1:

The technical process of present embodiment as shown in Figure 1, each processing step and corresponding processing parameter are as follows:

(1) bismuth nitrate solution preparation

Add electrolytic metal bismuth and industrial concentrated acid in reaction vessel, after the bismuth metal dissolving was complete, the bi content in the solution was controlled at 210g/l, free acid 5g/l.

(2) filter, remove insolubles

(3) hydrolysis reaction

In the reaction vessel of containing bismuth nitrate solution, add hydrolytic reagent industrial ammonia (NH ₃H ₂O), the endpoint pH of hydrating solution is controlled at 1.8, and hydrolysis reaction at room temperature carries out (not being subjected to the influence of seasonal variation).

(4) filter, wash

Filtration obtains hydrolysate BiONO ₃Filter cake, then with deionized water washing three times.

(5) slurrying

With washed BiONO ₃Filter cake is put into reaction vessel, adds deionized water then and is modulated into pulpous state.

(6) alkali conversion reaction

With the BiONO for preparing ₃Be dispersed in the NaOH solution, be transferred in the ultrasound reactor after being warming up to 40 ℃, reacted 20 minutes, endpoint pH is controlled at 12.

(7) filter, wash, dry

Filtration obtains converted product Bi ₂O ₃Filter cake washs its deionized water with 70 ℃ eight times, namely obtains Bi in 1 hour 250 ℃ of bakings then ₂O ₃Powder.

The Bi of present embodiment preparation ₂O ₃The technical indicator of powder is as follows;

Bi ₂O ₃Content 99.88%

Foreign matter content Fe 100 K 10 SO ₄10 Cu 20

(ppm) Ca?50 N?50 As 20 Na?100

Fisher particle size 1.77 μ m

Phase α-Bi ₂O ₃

Grain fineness number 400

Embodiment 2:

The technical process of present embodiment as shown in Figure 1, processing step is with embodiment 1, difference from Example 1 is the schedule of operation of the apolegamy and the conversion reaction of processing parameter.

In the bismuth nitrate solution for preparing, bi content is 288.2g/l, and free acid is 5g/l; Hydrolysis carries out under 10 ℃ of room temperatures, and hydrolytic reagent is industrial ammonia, and the endpoint pH of hydrating solution is controlled at 2.3; Filter the hydrolysate BiONO of gained ₃Filter cake adds then deionized water and makes slurries with deionized water washing three times; Conversion temperature is 85 ℃, two step conversion methods are adopted in conversion reaction, the first step transforms, the pH value is controlled at 10 (addition of NaOH be about theoretical amount 86%), and transformation time is controlled at 10 minutes, carries out second step after filtration, washing, the slurrying and transforms, the addition of NaOH is still take pH as 10 controls (be about theoretical amount 20%), can finish reaction in 5 minutes, twice conversion all under agitation carried out, and mixing speed is 60 rev/mins; Filter the Bi of gained ₂O ₃The filter cake temperature is that 80 ℃ deionized water is washed eight times, namely gets Bi in 1 hour 250 ℃ of bakings then ₂O ₃Powder.

The Bi that present embodiment is prepared ₂O ₃The technical indicator of powder is as follows:

Bi ₂O ₃Content 99.72%

Foreign matter content Fe 150 K 10 SO ₄20 Cu 25

(ppm) Ca?80 N?100 As?10 Na?150

Fisher particle size 1.83 μ m

Phase α-Bi ₂O ₃

Grain fineness number 450

Embodiment 3:

The technical process of present embodiment as shown in Figure 1, processing step is with embodiment 1, processing parameter is as follows:

In the bismuth nitrate solution for preparing, bi content is 260g/l, free acid 5g/l; Hydrolysis carries out under 24 ℃ of room temperatures, and hydrolytic reagent is industrial ammonia, and the endpoint pH of hydrating solution is controlled at 2.0; Filter the hydrolysate BiONO of gained ₃Filter cake adds then deionized water and makes slurries with deionized water washing three times; Conversion temperature is 24 ℃, and the addition of NaOH is 230% of theoretical amount, and transformation time is 70 minutes, transforms under agitation to carry out, and mixing speed is 80 rev/mins; Filter the Bi of gained ₂O ₃The filter cake temperature is that 80 ℃ deionized water is washed ten times, namely gets Bi in 1 hour 250 ℃ of bakings then ₂O ₃Powder.

Bi ₂O ₃Content 99.68%

Foreign matter content Fe 50 K 10 SO ₄10 Cu 30

(ppm) Ca?100 N?50 As 10 Na?200

Fisher particle size 1.68 μ m

Phase α-Bi ₂O ₃

Grain fineness number 450

The Bi of the present invention's preparation ₂O ₃Powder, purity and physical index all meet the requirement of electronic devices and components dopant material, are the high-quality dopant materials of the electronic components such as ceramic capacitor, ZnO varistor.

Claims

1. used in electronic industry Bi ₂O ₃The preparation method of powder, processing step is followed successively by:

(1) bismuth nitrate solution preparation,

(2) Bismuth trinitrate hydrolysis,

(3) filter, wash,

(4) hydrolysate bismuthyl nitrate slurrying,

(5) hydrolysate bismuthyl nitrate alkali transforms,

(6) filter, wash, dry,

It is characterized in that:

(1) the bismuth nitrate solution preparation is a raw material with highly purified electrolytic metal bismuth and industrial concentrated acid, and bi content is＞200～300g/1 in the bismuth nitrate solution for preparing,

(2) the Bismuth trinitrate hydrolysis is made hydrolytic reagent with industrial ammonia, and hydrolysis reaction at room temperature carries out, and the hydrating solution endpoint pH is controlled at 1.5～2.5,

(3) conversion of hydrolysate novismuth alkali is to add NaOH to make it be converted into Bi in the novismuth slurries ₂O ₃, conversion temperature is 10 ℃～90 ℃, and the addition of NaOH is by the control of pH value, and the pH value is 9-12, and transformation time shortens with the rising of conversion temperature, is 10 minutes～2 hours.

2. used in electronic industry Bi according to claim 1 ₂O ₃The preparation method of powder, it is characterized in that hydrolysate novismuth alkali transforms under agitation carries out, and conversion temperature is 70 ℃～90 ℃, adopt two step conversion methods, the first step transforms, and the addition of NaOH is 85%～90% of theoretical amount, and the novismuth major part is converted into Bi ₂O ₃, the second step conversion is carried out in slurrying after filtering, washing, and the addition of NaOH is 15～20% of theoretical amount.

3. used in electronic industry Bi according to claim 1 ₂O ₃The preparation method of powder, it is characterized in that hydrolysate novismuth alkali transforms carries out under ultrasonic vibration, and the optimal conversion temperature is 40 ℃～60 ℃.