CN102351204A - Method for preparing scintillation bismuth silicate powder by molten salt method - Google Patents

Abstract

The invention relates to the preparation of a scintillation crystal material and discloses a method for preparing a scintillation bismuth silicate powder by a molten salt method. The method provided by the invention comprises the following steps of: firstly using anhydrous ethanol as a ball milling medium, carrying out ball milling for 5 hours with the mol ratio of Bi2O3 to SiO2 being 1: 1.5-1: 2 to obtain a reaction raw material, carrying out hand force grinding on the dried reaction raw material and KCl at the mass ratio of 1: 4-4: 1 in a mortar for 30 min; putting a batch into an alumina crucible, putting the crucible into a muffle furnace, keeping warm at the temperature of 770-850 DEG C for 0.5-3 hours, taking out, and cooling; washing the cooled sample in supersonic wave by the use of deionized water, and drying to obtain the scintillation Bi4Si3O12 powder. The method provided by the invention can be used to simply and rapidly prepare the scintillation Bi4Si3O12 powder with high purity, and is convenient for large scale production.

Description

A kind of method for preparing the bismuth silicate powder that glimmers with molten-salt growth method

Technical field

The present invention relates to the preparation of scintillator crystal materials, disclose a kind of method for preparing the bismuth silicate powder that glimmers with molten-salt growth method.

Background technology

Bi ₄Si ₃O ₁₂Crystal mainly has flashing function, and it is transparent at visible light and near infrared region, and its response speed is than the scintillator Bi of present widespread use ₄Ge ₃O ₁₂Fast 3 times, half-width (FWHM) energy resolution of locating at 662keV (37Cs) is Bi ₄Ge ₃O ₁₂32%, anti-60Co gamma-rays radiating performance is greater than 105rad at emission peak 460nm place, radiation hardness compares Bi ₄Ge ₃O ₁₂A high one magnitude.Machinery and the chemical stability of height, the good characteristics of luminescence and low-cost advantage make Bi ₄Si ₃O ₁₂Crystal becomes one of rising scintillator.Can replace Bi in some aspects ₄Ge ₃O ₁₂, for example the high energy positron-electron is stored the calorimeter in the loop detection device.In addition, Bi ₄Si ₃O ₁₂Crystal also has performances such as electric light, thermoluminescence.

Although people are familiar with eulytite (Bi ₄Si ₃O ₁₂) there be more than 180 year, but just utilize Czochralski grown to go out Bi up to Philipsborn in 1971 etc. ₄Si ₃O ₁₂Monocrystalline.Because many advantages of this method, crystal pulling method are the main method of BSO monocrystalline of growing both at home and abroad always.What another kind was commonly used is falling crucible method, through prolonging platinum crucible smelting time and the suitable crystal growth furnace temperature that reduces, has obviously reduced defectives such as platinum inclusion, has finally obtained good monocrystalline.L.Armelao in 1998 etc. have prepared Bi with sol-gel method ₄Si ₃O ₁₂Film.Jin-Seong Kim equals to synthesize Bi with solid sintering technology in 2008 ₄Si ₃O ₁₂Pottery.

The conventional solid state reaction sintering process can be a raw materials mix with bismuth oxide and silicon oxide powder, makes bismuth silicate powder through solid state reaction.The shortcoming of this method is that the mixing of two kinds of raw materials is difficult to reach complete and homogeneous, and grain growing at high temperature, reunion, is difficult to obtain the desirable amount powder granule.Field clear spring, Zhang Zhengguang etc. have prepared Bi with solid phase method ₄Si ₃O ₁₂Powder is discovered, Bi ₄Si ₃O ₁₂Crystallite always distributes in pairs, and arranges in a row, and forms high orderly brilliant array structure.Employing solid phase methods such as Wang Yan have synthesized Bi ₂SiO ₅Powder, research is illustrated in the metastable phase Bi that generates in the solid state reaction process ₂SiO ₅Along with reaction times prolongation diffraction peak weakens, be increased in 900 ℃ of processes Bi by 700 ℃ in the solid state reaction temperature ₂SiO ₅Change Bi gradually into ₄Si ₃O ₁₂

Ba Xuewei, Bai Chaohui etc. are with tetraethoxy and Bi ₂O ₃Be raw material, adopt sol-gel method to prepare basic configuration and be bismuth silicate (Bi spherical, particle diameter 40-100nm ₄Si ₃O ₁₂) nano-powder, and studied the excitation spectrum and the emmission spectrum of powder.Bi ₄Si ₃O ₁₂Exciting of nano-powder mainly occurs between 250～275nm, and its maximum excitation wavelength is 261nm.The emmission spectrum of sample is a wideband spectrum, and maximum emission wavelength is positioned at 468nm.Compare with crystal, blue shift has taken place in the excitation spectrum and the emmission spectrum of BSO nano-powder.Infer that reason is that nanometer material structure groups of grains elemental size is very little, surface tension is very big, and distortion takes place granule interior shortens the bond distance, and the nano material average bond length is shortened, and the key chattering frequency raises as a result, causes blue shift.

Zhu Changren etc. are raw material with tetraethoxy and five water Bismuth trinitrates, adopt the chemical solution decomposition method to prepare Bi ₄Si ₃O ₁₂Powder.With X-ray diffractometer and scanning electron microscope analysis the phase structure and the pattern of powder, studied of the influence of the consumption of tetraethoxy to the powder phase composite.The result shows that the precursor powder was calcined 1 hour down at 650 ℃, had obtained single Bi ₄Si ₃O ₁₂Powder; Granular size is 3～5 μ m, is that the crystal grain of 300～500nm consists of the porous reticulated structure by several sizes; When bismuth silicon is 1: 2 than the consumption of (mol ratio), can prepares phase composite and be entirely Bi ₄Si ₃O ₁₂Powder.Consuming time when this method prepares precursor, it is poisonous to be used for the ethylene glycol monomethyl ether of regulator solution viscosity, and proportioning raw materials is not to generate Bi ₄Si ₃O ₁₂The proportioning of crystalline phase is unfavorable for big production.

Summary of the invention

In order to overcome the deficiency of above-mentioned prior art, the object of the present invention is to provide a kind ofly to prepare the method for the bismuth silicate powder that glimmers with molten-salt growth method, can prepare flicker Bi simply fast ₄Si ₃O ₁₂Powder, and product purity is high, is convenient to scale operation.

To achieve these goals, the technical scheme of the present invention's employing is:

A kind ofly prepare the method for the bismuth silicate powder that glimmers, may further comprise the steps with molten-salt growth method:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio～1: 2, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 1: 4～4: 1 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, be incubated 0.5～3 hour under 770 ℃～850 ℃ conditions, take out, be cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

Wherein, more than the cleaning in the 4th step can be carried out once repeatedly.

Compared with prior art, advantage of the present invention is:

(1) method is easy, easy handling, and reaction conditions is gentle;

(2) production cost is low, and preparation cycle is short, about 13～25h;

(3) product purity is high, can reach 85%～100%.

Description of drawings

Accompanying drawing is the bismuth silicate (Bi of embodiment one preparation ₄Si ₃O ₁₂) the diffraction photo that detects at X-ray diffractometer of powder, wherein X-coordinate be diffraction angle 2 θ/(°), ordinate zou is a diffracted intensity.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is explained further details.

Embodiment one

A kind ofly prepare the method for the bismuth silicate powder that glimmers, may further comprise the steps with molten-salt growth method:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 3: 2 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 1 hour under 770 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

Shown in accompanying drawing, be the bismuth silicate (Bi of present embodiment preparation ₄Si ₃O ₁₂) the diffraction photo that detects at X-ray diffractometer of powder, wherein X-coordinate be diffraction angle 2 θ/(°), ordinate zou is a diffracted intensity.

Embodiment two

A kind ofly prepare the method for the bismuth silicate powder that glimmers, may further comprise the steps with molten-salt growth method:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 3: 2 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 2 hours under 800 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

Embodiment three

A kind ofly prepare the method for the bismuth silicate powder that glimmers, may further comprise the steps with molten-salt growth method:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 2: 3 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 1 hour under 820 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

Embodiment four

A kind ofly prepare the method for the bismuth silicate powder that glimmers, may further comprise the steps with molten-salt growth method:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 1: 4 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 3 hours under 770 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

Embodiment five

A kind ofly prepare the method for the bismuth silicate powder that glimmers, may further comprise the steps with molten-salt growth method:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 2 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 4: 1 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 0.5 hour under 850 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

More than among each embodiment, the cleaning in the 4th step can be carried out repeatedly, effect is better.

Bi to above each embodiment preparation ₄Si ₃O ₁₂The powder analysis that makes an experiment, its purity can reach 85%～100%.

Claims (7)

1. one kind prepares the method for the bismuth silicate powder that glimmers with molten-salt growth method, it is characterized in that, may further comprise the steps:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio～1: 2, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 1: 4～4: 1 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, be incubated 0.5～3 hour under 770 ℃～850 ℃ conditions, take out, be cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

2. one kind prepares the method for the bismuth silicate powder that glimmers with molten-salt growth method, it is characterized in that, may further comprise the steps:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 3: 2 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 1 hour under 770 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

3. one kind prepares the method for the bismuth silicate powder that glimmers with molten-salt growth method, it is characterized in that, may further comprise the steps:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 3: 2 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 2 hours under 800 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

4. one kind prepares the method for the bismuth silicate powder that glimmers with molten-salt growth method, it is characterized in that, may further comprise the steps:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 2: 3 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 1 hour under 820 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

5. one kind prepares the method for the bismuth silicate powder that glimmers with molten-salt growth method, it is characterized in that, may further comprise the steps:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 1.5 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 1: 4 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 3 hours under 770 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

6. one kind prepares the method for the bismuth silicate powder that glimmers with molten-salt growth method, it is characterized in that, may further comprise the steps:

The first step is a ball-milling medium with the dehydrated alcohol, with Bi ₂O ₃And SiO ₂Ball milling was 5 hours in 1: 2 in molar ratio, as reaction raw materials;

In second step, reaction raw materials and the KCl of oven dry are ground 30min with mass ratio 4: 1 hand in mortar;

The 3rd step, admixtion is put into alumina crucible, then crucible is put into retort furnace, insulation is 0.5 hour under 850 ℃ of conditions, takes out, and is cooled to room temperature;

The 4th the step, with the refrigerative sample in ultrasonic wave with drying after the washed with de-ionized water, promptly get the Bi that glimmers ₄Si ₃O ₁₂Powder.

7. according to the preparation method of the described flicker bismuth silicate powder of the arbitrary claim of claim 1 to 6, it is characterized in that, carry out once above cleaning in said the 4th step.

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