阅读说明：本技术 Ito靶材的氧化锡粉末的制造方法 (Method for manufacturing tin oxide powder of ITO target material ) 是由 马建保 王志强 曾探 陶成 于 2021-07-13 设计创作，主要内容包括：本发明提供一种ITO靶材的氧化锡粉末的制造方法,通过溶解—熟成—pH调整—固液分离—干燥—焙烧—球磨—分级混合,最终制得的粉末粒度细,分布范围窄和均匀,团聚程度轻,粉末纯度高,呈现出单分散性,粉末收率高,可大批量生产。(The invention provides a method for preparing tin oxide powder of an ITO target, which comprises the steps of dissolving, ripening, pH adjustment, solid-liquid separation, drying, roasting, ball milling and grading mixing, wherein the finally prepared powder has the advantages of fine granularity, narrow and uniform distribution range, light agglomeration degree, high powder purity, monodispersity and high powder yield, and can be produced in large batch.)

1. A method for manufacturing tin oxide powder of an ITO target is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: firstly, adding 30-50 wt% of AR nitric acid solution into a closed container, starting heating and stirring, wherein the dissolving temperature reaches 40-80 ℃, adding a certain amount of metallic tin particles with the diameter of 2-8mm and the purity of more than or equal to 99.993% in a dividing or continuous mode, the reaction temperature in the process is 105 +/-5 ℃, adding a certain amount of deionized water with the temperature of 60-100 ℃ to fix the volume to 6-11 wt% within 1 hour after the tin particles are added, filtering, continuously stirring for 10-60min, and standing for 4-15 hours;

step two: and (3) ripening: when the temperature of the solution reaches below 40 ℃, extracting supernatant, adding deionized water at 30-40 ℃, stirring, standing for more than 1h, and extracting supernatant; repeating the steps until the conductivity of the solution reaches a specified range, wherein the container needs to be insulated in the process;

step three: then, regulating the solution to constant volume and pH to be within the range of 6-9 to obtain tin oxide slurry;

step four: carrying out solid-liquid separation on the tin oxide slurry to obtain a wet material;

step five: drying the wet material to obtain a tin oxide precursor;

step six: roasting the tin oxide precursor to obtain tin oxide powder;

step seven: and ball-milling the tin oxide powder, and mixing the tin oxide powder in a grading way after ball milling to obtain a finished product.

2. The method for producing tin oxide powder for an ITO target according to claim 1, wherein: in the first step, the tin particles are added at a constant speed, and the adding time of the tin particles, namely the reaction time, is 4-7 h.

3. The method for producing tin oxide powder for an ITO target according to claim 1, wherein:

the third step of constant volume pH adjustment specifically comprises the following steps: adding water to a certain volume, keeping the volume constant, stirring for more than 10min, adding 10-20 wt% of ammonia water solution at a fixed quantity and a fixed speed while continuing stirring, and adjusting the pH value of the solution to be within the range of 6-9.

4. The method for producing tin oxide powder for an ITO target according to claim 1, wherein: the solid-liquid separation in the fourth step specifically comprises the following steps: firstly, filtering the tin oxide slurry by adopting filter cloth with 1000 meshes to 2300 meshes, and then carrying out solid-liquid separation by adopting a centrifugal mode.

5. The method for producing tin oxide powder for an ITO target according to claim 1, wherein: the step five of drying the wet materials specifically comprises the following steps: drying at a temperature not higher than 150 ℃, and performing multi-stage drying by adopting low-temperature drying and high-temperature drying, wherein primary crushing is performed in the low-temperature drying process.

6. The method for producing tin oxide powder for an ITO target according to claim 1, wherein: the roasting in the sixth step is specifically as follows: and (3) putting the tin oxide precursor into a crucible, perforating the powder, putting the crucible into a roasting furnace, setting the temperature to be 600-1000 ℃, keeping the temperature rise rate to be not more than 6 ℃/min and the heat preservation time to be 2-6 h, and roasting to obtain the tin oxide powder with different particle size requirements and distributions.

7. The method for producing tin oxide powder for an ITO target according to claim 1, wherein: the step seven ball milling specifically comprises the following steps: and (3) carrying out dry ball milling on the tin oxide powder, wherein the material ball ratio is 1: 1-1: 5, the ball milling time is not more than 48h, the types of zirconium balls are as long as 2+ as long as 5+ as long as 10, and the filling ratio is not more than 70%.

8. The method for producing tin oxide powder for an ITO target according to claim 7, wherein: the seven-stage mixing specifically comprises the following steps: separating and sieving the ball-milled material balls, classifying the powder, mixing, wherein the classifying mesh number is more than 100 meshes, the mixing time is more than 1h, the filling ratio is less than 70%, and then sampling and detecting.

Technical Field

The invention relates to the field of tin oxide of an ITO target, in particular to a method for manufacturing tin oxide powder of the ITO target.

Background

Tin oxide (chemical formula: SnO 2) is an important semiconductor material, and a doped thin film prepared from the tin oxide has excellent photoelectric characteristics such as high conductivity, high visible light transmittance, high stability, high hardness, microwave attenuation, ultraviolet reflection, strong corrosion resistance and the like, is mainly used as a raw material of an ITO (indium tin oxide) target material, and is widely applied to the fields of lithium batteries, solar batteries, liquid crystal displays, optoelectronic devices, transparent conductive electrodes, infrared detection protection and the like.

The current methods for preparing tin oxide powder, also known as ITO target material, at high density include chemical precipitation, vapor phase synthesis, spray combustion, solid phase chemical synthesis, sol-gel, hydrothermal synthesis, and nitric acid oxidation.

The chemical precipitation method has simple equipment and process and is easy for industrial production, but the tin dioxide ultrafine powder is easy to agglomerate; the gas-phase synthesis method has coarse and uncontrollable granularity; the spray combustion method has fine granularity but high production cost; the solid phase synthesis method has simple process, but the appearance is not easy to control; the sol-gel method has simple equipment and easy operation, but has longer treatment time and is not easy to wash; the hydrothermal synthesis reaction is carried out in a water system, a large amount of waste water is generated, the purity is difficult to control, and the filtration is difficult. Nitric acid oxidation has nitrogen oxide pollution, mainly particle size is not easy to control, and some steps of the process have difficulty in mass production.

The final tin oxide powder has moderate, fine and uniform particle size, and the methods have the problems of small particle size of tin oxide particles, easy agglomeration, mass production realizability and the like.

The chemical method for preparing the nano tin oxide inevitably encounters the problem of a dissolving system of raw materials, in a mainstream hydrochloric acid and nitric acid system, the hydrochloric acid system is greatly influenced by the electronegativity of Cl-root, the accumulation state of powder is greatly influenced, the use of the final ITO target is greatly influenced (the problems of target nodulation poisoning, acid and the like), and the unconventional mode cannot meet the requirement of large-scale mass production.

Patent CN1926644A discloses a conductive tin oxide powder and a method for producing the same, wherein a sodium stannate solution is slowly added to an acid aqueous solution to react, the pH value at the end of the addition is 5 or less, the resulting slurry is washed, filtered, dried, and the resulting dried powder is pulverized and then calcined in a non-oxidizing environment. However, the powder prepared by the nitric acid system is also easy to agglomerate, and after dissolution, the alpha (n-stannic acid) and beta (metastannic acid) tin oxide slurries with high temperature and high acidity have large washing difficulty (the two types are mutually converted, the aging process is favorable for the conversion of the alpha (n) -type to the beta (beta-metastannic acid)), the yield is low, the subsequent process treatment difficulty is large, the particle size is not easy to control, and the industrial production is not favorable.

Disclosure of Invention

In order to solve the problems, the invention provides a method for preparing tin oxide powder of an ITO target, which comprises the steps of dissolving, ripening, pH adjustment, solid-liquid separation, drying, roasting, ball milling and grading mixing, and the finally prepared powder has the advantages of fine granularity, narrow and uniform distribution range, light agglomeration degree, high powder purity, monodispersity and high powder yield, can be produced in large batch, and solves the problems in the background technology.

The invention aims to provide a method for manufacturing tin oxide powder of an ITO target, which is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: firstly, adding 30-50 wt% of AR nitric acid solution into a closed container, starting heating and stirring, wherein the dissolving temperature reaches 40-80 ℃, adding a certain amount of metallic tin particles with the diameter of 2-8mm and the purity of more than or equal to 99.993% in a dividing or continuous mode, the reaction temperature in the process is 105 +/-5 ℃, adding a certain amount of deionized water with the temperature of 60-100 ℃ to fix the volume to 6-11 wt% within 1 hour after the tin particles are added, filtering, continuously stirring for 10-60min, and standing for 4-15 hours;

step two: and (3) ripening: when the temperature of the solution reaches below 40 ℃, extracting supernatant, adding deionized water at 30-40 ℃, stirring, standing for more than 1h, and extracting supernatant; repeating the steps until the conductivity of the solution reaches a specified range, wherein the container needs to be insulated in the process;

step three: then, regulating the solution to constant volume and pH to be within the range of 6-9 to obtain tin oxide slurry;

step four: carrying out solid-liquid separation on the tin oxide slurry to obtain a wet material;

step five: drying the wet material to obtain a tin oxide precursor;

step six: roasting the tin oxide precursor to obtain tin oxide powder;

step seven: and ball-milling the tin oxide powder, and mixing the tin oxide powder in a grading way after ball milling to obtain a finished product.

The further improvement lies in that: in the first step, the tin particles are added at a constant speed, and the adding time of the tin particles, namely the reaction time, is 4-7 h.

The further improvement lies in that: the third step of constant volume pH adjustment specifically comprises the following steps: adding water to a certain volume, keeping the volume constant, stirring for more than 10min, adding 10-20 wt% of ammonia water solution at a fixed quantity and a fixed speed while continuing stirring, and adjusting the pH value of the solution to be within the range of 6-9.

The further improvement lies in that: the solid-liquid separation in the fourth step specifically comprises the following steps: firstly, filtering the tin oxide slurry by adopting filter cloth with 1000 meshes to 2300 meshes, and then carrying out solid-liquid separation by adopting a centrifugal mode.

The further improvement lies in that: the step five of drying the wet materials specifically comprises the following steps: drying at a temperature not higher than 150 ℃, and performing multi-stage drying by adopting low-temperature drying and high-temperature drying, wherein primary crushing is performed in the low-temperature drying process.

The further improvement lies in that: the roasting in the sixth step is specifically as follows: and (3) putting the tin oxide precursor into a crucible, perforating the powder, putting the crucible into a roasting furnace, setting the temperature to be 600-1000 ℃, keeping the temperature rise rate to be not more than 6 ℃/min and the heat preservation time to be 2-6 h, and roasting to obtain the tin oxide powder with different particle size requirements and distributions.

The further improvement lies in that: the step seven ball milling specifically comprises the following steps: and (3) carrying out dry ball milling on the tin oxide powder, wherein the material ball ratio is 1: 1-1: 5, the ball milling time is not more than 48h, the types of zirconium balls are as long as 2+ as long as 5+ as long as 10, and the filling ratio is not more than 70%.

The further improvement lies in that: the seven-stage mixing specifically comprises the following steps: separating and sieving the ball-milled material balls, classifying the powder, mixing, wherein the classifying mesh number is more than 100 meshes, the mixing time is more than 1h, the filling ratio is less than 70%, and then sampling and detecting.

The invention has the beneficial effects that: dissolving, curing, pH adjusting, solid-liquid separating, drying, roasting, ball milling and grading mixing, wherein the concentration of nitric acid in the dissolving process is not more than 50wt% and not less than 30wt%, the diameter of tin particles is 2-8mm, tin particles are added at a constant speed, the adding time of the tin particles, namely the reaction time is 4-7h, the dissolving temperature is 40-80 ℃, the reaction temperature in the process is controlled to be 105 +/-5 ℃, the constant volume concentration is 6-11 wt%, and the good dissolving effect of the nitric acid and the tin particles is ensured; the ripening temperature is below 40 ℃ and is added to 30-40 ℃, so that the ripening effect is ensured, the crystal form conversion process is complete, and meanwhile, the container needs to be insulated to control the natural cooling speed and prevent the excessive cooling; the pH adjustment is to add 10wt% -20wt% ammonia water to adjust to 6-9 after stirring for 10min, so as to ensure the yield of powder; the drying adopts a low-temperature and high-temperature multi-section drying mode, primary crushing is needed, and agglomeration at a precursor stage is reduced; the ball milling ball ratio is 1: 1-1: 5, the ball milling time is not more than 48 hours, the zirconium ball type is in the middle of 2+ in the middle of 5+ in the middle of 10, the filling ratio is not more than 70%, and the final powder granularity is ensured; the finally prepared powder has fine granularity, narrow and uniform distribution range, light agglomeration degree, high powder purity, monodispersity and high powder yield, and can be produced in large batch.

Drawings

FIG. 1 is a particle size diagram of tin oxide powder produced according to an embodiment of the present invention.

FIG. 2 is an SEM photograph (scale: 1um) of tin oxide powder produced by an embodiment of the present invention.

Detailed Description

For the purpose of enhancing understanding of the present invention, the present invention will be further described in detail with reference to the following examples, which are provided for illustration only and are not to be construed as limiting the scope of the present invention.

The embodiment provides a method for manufacturing tin oxide powder of an ITO target, which comprises the following specific steps:

s1: in a closed container, metal tin particles with the purity of more than or equal to 99.993 percent and the diameter of 2-8mm based on metal impurities react with AR nitric acid solution with the concentration of 40wt%, acid solution is added into the container, heating and stirring are started, the dissolving temperature reaches 60 ℃, tin particles are added at a constant speed, the adding time of the tin particles, namely the reaction time, is controlled to be 5 hours, the process reaction temperature is not more than 110 ℃, a certain amount of 80 ℃ deionized water is added to the tin particles within 1 hour after the reaction is finished, the volume is fixed to 8wt%, the tin particles are filtered, stirring is continued for 40min, and standing is carried out for 10 hours, so that the good dissolving effect of the nitric acid and the tin particles is ensured.

S2: when the temperature of the solution reaches below 40 ℃, extracting supernatant, adding deionized water at 50 ℃, stirring, standing for more than 1 hour, and extracting supernatant; repeating the step until the conductivity of the solution reaches a specified range; the temperature is controlled below 40 ℃, so that the completeness of the ripening effect and the complete crystal form conversion process can be ensured; meanwhile, the container needs to be insulated to control the natural cooling speed and prevent the excessive cooling.

S3: adding water to a certain volume, keeping the volume constant, stirring for more than 10min, adding 15wt% ammonia water while stirring, and adjusting the pH of the solution to 7 to obtain the tin oxide slurry.

S4: filtering the tin oxide slurry by adopting filter cloth with 1000 meshes to 2300 meshes, and then carrying out solid-liquid separation by adopting a centrifugal mode.

S5: the wet material drying specifically comprises the following steps: drying at the temperature not more than 150 ℃, and drying at low temperature and high temperature for multiple sections to obtain the tin oxide precursor, wherein in the low-temperature drying process, the tin oxide precursor is crushed for the first time to reduce agglomeration of the precursor.

S6: and (3) putting the tin oxide precursor into a crucible, perforating the powder, putting the crucible into a roasting furnace, setting the temperature to be 80000 ℃, heating the powder at a rate of not more than 6 ℃/min, keeping the temperature for 4h, and roasting to obtain the tin oxide powder with different particle size requirements and distributions.

S7: and (3) carrying out dry ball milling on the tin oxide powder, wherein the material ball ratio is 1: 1-1: 5, the ball milling time is not more than 48h, the zirconium ball type is in the middle of 2+ in the middle of 5+ in the middle of 10, and the filling ratio is not more than 70%, so that the particle size of the final powder is ensured.

S8: separating and sieving the ball-milled material balls, classifying the powder, mixing, wherein the classifying mesh number is more than 100 meshes, the mixing time is more than 1h, the filling ratio is less than 70%, and then sampling and detecting.

The particle size distribution of the mass-produced powder of the above process is shown in FIG. 1 (volume distribution, apparatus: Marvin MS-3000): d50 is 0.2-0.3um, and D90 is less than 0.6 um. The powder BET is controlled within the range of 4-13 m 2/g.

As shown in fig. 2, SEM photographs of the final mass-produced tin oxide powder revealed that the finally produced powder was fine in particle size, narrow and uniform in distribution range, light in degree of agglomeration, high in powder purity, exhibiting monodispersity, and high in powder yield, and was mass-producible.