阅读说明：本技术 一种真空蒸馏提纯金属锰的方法 (Method for purifying manganese metal by vacuum distillation ) 是由 姚力军 郭廷宏 潘杰 王学泽 章晨 于 2021-09-30 设计创作，主要内容包括：本发明提供了一种真空蒸馏提纯金属锰的方法,将原料锰在真空条件下进行加热,通过冷凝装置收集蒸馏出来的锰蒸汽,冷凝得到金属锰；其中,需要严格控制所述真空条件的真空度为10～(-5)-1Pa,所述加热的目标温度为1250-1400℃。本发明所述方法采用真空蒸馏工艺提纯金属锰,不仅可以将市售原料锰提纯至纯度为4N5-5N,金属锰中杂质总含量＜50ppm,且气体元素杂质总含量＜100ppm,每1g金属锰中粒径＞1.3μm的非金属不溶夹杂物数量＜5000个,满足半导体靶材原料的要求,还具有流程简单、能耗低、环境污染小等优点。(The invention provides a method for purifying manganese metal by vacuum distillation, which comprises the steps of heating a raw material manganese under a vacuum condition, collecting distilled manganese steam by a condensing device, and condensing to obtain the manganese metal; wherein the vacuum degree required for strictly controlling the vacuum condition is 10 ‑5 -1Pa, and the target temperature of the heating is 1250-. The method adopts a vacuum distillation process to purify the manganese metal, not only can purify the manganese raw material sold in the market to the purity of 4N5-5N, the total content of impurities in the manganese metal is less than 50ppm, the total content of gas element impurities is less than 100ppm, and the number of non-metal insoluble inclusions with the grain diameter of more than 1.3 mu m in each 1g of the manganese metal is less than 5000, thereby meeting the requirements of the raw material of the semiconductor target material, but also has the advantages of simple process, low energy consumption, small environmental pollution and the like.)

1. The method for purifying the manganese metal by vacuum distillation is characterized by comprising the following steps: heating the raw material manganese under a vacuum condition, condensing and collecting distilled manganese steam, and condensing to obtain metal manganese;

wherein the vacuum degree of the vacuum condition is 10^-5-1Pa, and the target temperature of the heating is 1250-.

2. The method according to claim 1, wherein the purity of the raw material manganese is 2N-3N;

preferably, the metal impurities in the raw material manganese comprise any one or a combination of at least two of Pb, Zn, Mg, Al, Ni, Fe or Cr;

preferably, the non-metallic impurities in the raw material manganese comprise any one or a combination of at least two of Se, Si, C, H, O, N, S or Cl;

preferably, the purity of the metal manganese obtained by condensation is 4N 5-5N.

3. The method of claim 1 or 2, wherein the heating comprises a primary heating, a secondary heating, and a tertiary heating, and a final temperature of the tertiary heating is the target temperature.

4. The method according to claim 3, wherein the temperature rise rate of the first-stage temperature rise is 5-10 ℃/min;

preferably, the end temperature of the first-stage temperature rise is 350-450 ℃;

preferably, the first-stage temperature rise is kept for 30-60 min.

5. The method according to claim 3 or 4, wherein the temperature rise rate of the secondary temperature rise is 5-10 ℃/min;

preferably, the end temperature of the secondary heating is 900-1100 ℃.

6. The method according to any one of claims 3 to 5, wherein the temperature rise rate of the three-stage temperature rise is 1 to 5 ℃/min;

preferably, the heat preservation time of the third-stage temperature rise is 30-180 min.

7. The process according to any one of claims 1 to 6, wherein the condensation is carried out in a condensation unit comprising a condensation tray of stages 8 to 10;

preferably, the steam passage openings of the condensation trays are stacked alternately;

preferably, a condensation disc close to the raw material manganese is a grade 1 condensation disc, and the metal manganese obtained by condensation is positioned on the grade 3-6 condensation disc;

preferably, the condensation surface of the 1 st-stage condensation plate is an inclined surface, the edge of the condensation surface is not provided with a baffle, the condensation surfaces of the other condensation plates are flat, and the edges of the condensation surfaces are provided with baffles;

preferably, the condensation surface of the condensation plate of the 1 st stage has an inclination of 10-15 degrees.

8. The method according to any one of claims 1 to 7, wherein the heating is stopped and cooling is performed after the vacuum distillation purification is finished;

preferably, a shielding gas is introduced during the cooling;

preferably, the shielding gas comprises argon.

9. The method according to claim 8, characterized in that, after the cooling is finished, the manganese metal obtained by condensation is subjected to acid washing;

preferably, the acid solution used for acid washing is a nitric acid solution;

preferably, the concentration of the nitric acid solution is 1-5 wt.%;

preferably, the pickling time is 5-10 min.

10. A method according to any of claims 1-9, characterized in that the method comprises the following:

putting the raw material manganese with the purity of 2N-3N into the vacuum degree of 10^-5Sequentially carrying out heating treatment of primary heating, secondary heating and tertiary heating under the vacuum condition of-1 Pa, and specifically: heating to 350-; heating to 900-; heating to the target temperature of 1250-; collecting the distilled manganese steam through a condensing device, and condensing to obtain metal manganese with the purity of 4N 5-5N;

wherein the metal impurities in the raw material manganese comprise any one or the combination of at least two of Pb, Zn, Mg, Al, Ni, Fe or Cr; the non-metallic impurities in the raw material manganese comprise any one or the combination of at least two of Se, Si, C, H, O, N, S or Cl;

the condensing device comprises 8-10 stages of condensing discs; the steam channel openings of the condensing discs are alternately stacked; a condensation disc close to the raw material manganese is a grade 1 condensation disc, and the metal manganese obtained by condensation is positioned on a grade 3-6 condensation disc; the condensation surface of the 1 st-stage condensation plate is an inclined surface, the edge of the condensation surface is not provided with a baffle, the condensation surfaces of the other condensation plates are flat, and the edges of the condensation surfaces are provided with baffles; the condensing surface of the 1 st-stage condensing disc is inclined by 10-15 degrees;

stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; and (3) carrying out acid washing on the metal manganese obtained by condensation for 5-10min by adopting a nitric acid solution with the concentration of 1-5 wt.%.

Technical Field

The invention relates to the technical field of metal purification, relates to pyrogenic process purification of manganese metal, and particularly relates to a method for purifying manganese metal by vacuum distillation.

Background

With the rapid development of very large scale integrated circuits, the size of chips for semiconductors has been reduced to nanometer level, RC delay and electromigration of metal interconnects have become major factors affecting the performance of chips, and conventional aluminum and aluminum alloy interconnects have not been able to meet the requirements of process of very large scale integrated circuits. Compared with aluminum, copper has higher electromigration resistance and higher conductivity, and particularly ultra-high-purity copper with the purity of more than or equal to 6N has important significance for reducing the resistance of a chip interconnection line and improving the operation speed of the chip interconnection line. However, below the 28nm process node, the electromigration problem of the ultra-high purity copper is serious, and a self-diffusion barrier layer can be formed by adding trace Mn element into the ultra-high purity copper, so that the electromigration can be effectively reduced.

Common manganese in the market is prepared by electrolysis of a manganese sulfate-ammonium sulfate system, generally contains hundreds of ppm of metal impurities and thousands of ppm of non-metal impurities, and cannot meet the requirements of semiconductor target raw materials. For example, CN105200453A discloses a preparation process for electrolytic refining of high purity manganese, which prepares high purity manganese with a purity of not less than 99.999% by deeply purifying manganese sulfate solution and purifying manganese metal by combining with secondary electrolytic refining, and the process steps are as follows in sequence: 1) purifying a manganese sulfate solution to remove impurities, and removing the impurities through ion exchange; 2) performing primary electrolytic refining, controlling electrolysis process parameters, and performing diaphragm electrolysis by using an insoluble anode to obtain a primary manganese metal product; 3) and (4) secondary electrolytic refining purification, namely preparing the high-purity manganese with flatness and metallic luster by taking the primary metal manganese product as an anode. However, the method has the defects of complex flow, high energy consumption, high environmental pollution and the like, and the control of the content of non-metallic impurities such as carbon, hydrogen, oxygen, nitrogen and the like is not mentioned.

In order to improve the purity of manganese metal used for semiconductors, it is necessary to develop a novel method for purifying manganese metal, which is a method for purifying manganese metal by using a vacuum distillation process.

Disclosure of Invention

In view of the problems in the prior art, the invention provides a method for purifying manganese metal by vacuum distillation, which comprises the steps of heating raw material manganese under a vacuum condition, collecting distilled manganese steam by a condensing device, and condensing to obtain manganese metal(ii) a Wherein the vacuum degree required for strictly controlling the vacuum condition is 10^-5-1Pa, and the target temperature of the heating is 1250-. The method adopts a vacuum distillation process to purify the manganese metal, not only can purify the manganese raw material sold in the market to the purity of 4N5-5N, the total content of impurities in the manganese metal is less than 50ppm, the total content of gas element impurities is less than 100ppm, and the number of non-metal insoluble inclusions with the grain diameter of more than 1.3 mu m in each 1g of the manganese metal is less than 5000, thereby meeting the requirements of the raw material of the semiconductor target material, but also has the advantages of simple process, low energy consumption, small environmental pollution and the like.

It is worth noting that the manganese metal used in semiconductors has very high quality requirements on purity, with different detection methods based on impurity elements having different requirements. The purity of manganese measured by GDMS is required to reach 4N5-5N, namely the purity, and the total content of other elements measured by GDMS is the total content of impurities in the metal manganese measured by GDMS and is required to meet the requirement of less than 50 ppm; the total impurity content of C, H, O, N four gas elements was measured using a gas analyzer from LECO, usa, and was required to be less than 100 ppm.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention aims to provide a method for purifying manganese metal by vacuum distillation, which is characterized by comprising the following steps: heating the raw material manganese under a vacuum condition, condensing and collecting distilled manganese steam, and condensing to obtain metal manganese;

wherein the vacuum degree of the vacuum condition is 10^-5-1Pa, and the target temperature of the heating is 1250-.

The method adopts a vacuum distillation process, so that main manganese metal and impurity elements volatilize together when raw manganese is distilled in vacuum, a condensing device comprising a multi-stage condensing disc is arranged according to the difference of the boiling points of the elements, substances with the boiling points higher than that of the manganese metal are condensed in a region with higher temperature of the condensing device, namely, in a region close to the heated raw manganese metal, substances with the boiling points lower than that of the manganese metal are condensed in a region with lower temperature of the condensing device, namely, in a region far away from the heated raw manganese metal, and the main manganese metal is condensed in the middle of the condensing device, so that the raw manganese metal is purified to the manganese metal with the purity of 4N5-5N, the total content of impurities in the manganese metal measured by GDMS is less than 50ppm, the total content of non-metal impurities is less than 100ppm, and the number of non-metal insoluble impurities with the grain diameter of more than 1.3 mu m in each 1g of the manganese metal is less than 5000, the method meets the requirements of the raw materials of the semiconductor target material, and has the advantages of simple process, low energy consumption, small environmental pollution and the like.

Moreover, the method for purifying the manganese metal by vacuum distillation needs to strictly control the vacuum degree of the vacuum condition to be 10^-5-1Pa, and the target temperature of heating is 1250-¹mmHg, compared with the saturated vapor pressure of Se, Pb, Zn, Mg and other impurity elements of 10³The mmHg level is two orders of magnitude higher than the saturated vapor pressure of the metal manganese, the metal manganese is easier to volatilize, and the saturated vapor pressure of impurity elements such as Al, Si, Ni, Fe, Cr and the like is 10^-1-10^-3mmHg is lower than the saturated vapor pressure of the manganese metal and is more difficult to volatilize compared with the manganese metal, so that the manganese metal can be purified by a condensing device comprising a multi-stage condensing disc, the purifying effect can be ensured, the recovery rate of the manganese metal is improved, the production efficiency can be improved as much as possible, and the vacuum distillation time is shortened.

In a preferred embodiment of the present invention, the purity of the manganese raw material is 2N to 3N, for example, 2N1, 2N3, 2N4, 2N5, 2N7, 2N8 or 3N, but the purity is not limited to the above-mentioned values, and other values not listed in the above-mentioned range are also applicable.

Preferably, the metal impurities in the raw material manganese comprise any one or a combination of at least two of Pb, Zn, Mg, Al, Ni, Fe and Cr, and since the raw material manganese is generally a commercially available electrolytic manganese product according to the present invention, the metal impurities in the raw material manganese often contain Pb, Zn, Mg, Al, Ni, Fe and Cr at the same time.

Preferably, the non-metallic impurities in the raw material manganese comprise any one or a combination of at least two of Se, Si, C, H, O, N, S and Cl, and since the raw material manganese is generally a commercially available electrolytic manganese product according to the present invention, the non-metallic impurities in the raw material manganese often contain Se, Si, C, H, O, N, S and Cl at the same time.

Preferably, the purity of the manganese metal obtained by condensation is 4N5-5N, such as 4N5, 4N6, 4N7, 4N8, 4N9 or 5N, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

As a preferable technical solution of the present invention, the heating includes a first-stage temperature rise, a second-stage temperature rise, and a third-stage temperature rise, and an end point temperature of the third-stage temperature rise is the target temperature.

In a preferred embodiment of the present invention, the first-stage heating rate is 5 to 10 ℃/min, for example, 5 ℃/min, 6 ℃/min, 7 ℃/min, 8 ℃/min, 9 ℃/min, or 10 ℃/min, but the first-stage heating rate is not limited to the above-mentioned values, and other values not shown in the above-mentioned range of values are also applicable.

Preferably, the end point temperature of the first-stage temperature rise is 350-450 ℃, such as 350 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃, 410 ℃, 430 ℃ or 450 ℃, but is not limited to the recited values, and other unrecited values within the range of values are equally applicable.

Preferably, the first-stage heating is performed for 30-60min, such as 30min, 35min, 40min, 45min, 50min, 55min or 60min, but not limited to the recited values, and other values not recited in the range of values are also applicable.

It is worth to say that the first-stage heating of the invention is carried out for 30-60min at the temperature of 350-450 ℃, which is beneficial to removing C, H, O, N-containing volatile impurities.

In a preferred embodiment of the present invention, the temperature increase rate of the secondary heating is 5 to 10 ℃/min, for example, 5 ℃/min, 6 ℃/min, 7 ℃/min, 8 ℃/min, 9 ℃/min, or 10 ℃/min, but the temperature increase rate is not limited to the above-mentioned values, and other values not shown in the above-mentioned range of values are also applicable.

Preferably, the end point temperature of the secondary temperature rise is 900-.

In a preferred embodiment of the present invention, the rate of the three-stage heating is 1 to 5 ℃/min, for example, 1 ℃/min, 1.5 ℃/min, 2 ℃/min, 2.5 ℃/min, 3 ℃/min, 3.5 ℃/min, 4 ℃/min, 4.5 ℃/min, or 5 ℃/min, but is not limited to the above-mentioned values, and other values not listed in the above-mentioned numerical range are also applicable.

Preferably, the temperature of the three-stage heating is 30-180min, such as 30min, 50min, 70min, 80min, 100min, 130min, 150min or 180min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

It is worth to say that the second-level heating of the invention adopts a higher heating rate of 5-10 ℃/min, the temperature is raised from 350-

As a preferred technical scheme of the invention, the condensation collection is carried out in a condensation device, and the condensation device comprises 8-10 stages of condensation discs.

Preferably, the vapor passage openings of the condensation plates are alternately stacked such that the metal vapor generated by distillation moves outward in an "S" shape in the condensation device.

Preferably, the condensation plate close to the raw material manganese is a grade 1 condensation plate, and the metal manganese obtained by condensation is positioned on the grade 3-6 condensation plate, namely the middle position of the condensation device containing the grade 8-10 condensation plate.

Preferably, the condensation surface of the 1 st-stage condensation plate is an inclined surface, no baffle is arranged at the edge of the condensation surface, and the condensation surfaces of the rest condensation plates are flat surfaces and provided with baffles at the edges.

Preferably, the condensation surface of the condensation plate of the 1 st stage has an inclination of 10 to 15 degrees, such as 10 degrees, 11 degrees, 12 degrees, 13 degrees, 14 degrees or 15 degrees, but not limited to the recited values, and other values not recited in the range of values are also applicable.

In a preferred embodiment of the present invention, the heating is stopped and the cooling is performed after the vacuum distillation purification is completed.

Preferably, a shielding gas is introduced during said cooling, which may accelerate the cooling.

Preferably, the shielding gas comprises argon.

As the preferable technical scheme of the invention, the metal manganese obtained by condensation is subjected to acid washing, so that impurities deposited on the metal manganese in the stages of temperature rise and temperature reduction can be effectively removed.

Preferably, the acid solution used for acid washing is a nitric acid solution.

Preferably, the nitric acid solution has a concentration of 1-5 wt.%, e.g., 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.% or 5 wt.%, etc., but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

Preferably, the time for the acid washing is 5-10min, such as 5min, 6min, 7min, 8min, 9min or 10min, but not limited to the recited values, and other values not recited in the range of values are equally applicable.

As a preferable technical scheme of the invention, the method comprises the following steps:

putting the raw material manganese with the purity of 2N-3N into the vacuum degree of 10^-5Sequentially carrying out heating treatment of primary heating, secondary heating and tertiary heating under the vacuum condition of-1 Pa, and specifically: heating to 350-; heating to 900-; heating to the target temperature of 1250-; collecting the distilled manganese steam through a condensing device, and condensing to obtain metal manganese with the purity of 4N 5-5N;

wherein the metal impurities in the raw material manganese comprise any one or the combination of at least two of Pb, Zn, Mg, Al, Ni, Fe or Cr; the non-metallic impurities in the raw material manganese comprise any one or the combination of at least two of Se, Si, C, H, O, N, S or Cl;

the condensing device comprises 8-10 stages of condensing discs; the steam channel openings of the condensing discs are alternately stacked; a condensation disc close to the raw material manganese is a grade 1 condensation disc, and the metal manganese obtained by condensation is positioned on a grade 3-6 condensation disc; the condensation surface of the 1 st-stage condensation plate is an inclined surface, the edge of the condensation surface is not provided with a baffle, the condensation surfaces of the other condensation plates are flat, and the edges of the condensation surfaces are provided with baffles; the condensing surface of the 1 st-stage condensing disc is inclined by 10-15 degrees;

stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; and (3) carrying out acid washing on the metal manganese obtained by condensation for 5-10min by adopting a nitric acid solution with the concentration of 1-5 wt.%.

By utilizing the method for purifying the manganese metal by vacuum distillation, the impurity elements such as Al, Si, Ni, Fe, Cr and the like with high boiling point and low saturated vapor pressure can be volatilized and condensed in the condensation tray of the lower part of the condensation device in a higher temperature area, the impurity elements such as Se, Pb, Zn, Mg and the like with low boiling point and high saturated vapor pressure can be volatilized and condensed in the condensation tray of the upper part of the condensation device in a lower temperature area, so that the high-purity manganese metal is condensed in the middle area of the condensation device, and the purity requirement of the manganese metal for semiconductors is met.

Compared with the prior art, the invention at least has the following beneficial effects:

(1) the method adopts a vacuum distillation process to purify the manganese metal, can purify the manganese metal of which the purity is 4N5-5N from the manganese raw material sold in the market, wherein the total impurity content in the manganese metal measured by GDMS is less than 50ppm, the total impurity content of gas elements is less than 100ppm, and the number of non-metallic insoluble inclusions with the grain diameter of more than 1.3 mu m in each 1g of the manganese metal is less than 5000, thereby meeting the requirements of the raw material of the semiconductor target material;

(2) the method for purifying the manganese metal by vacuum distillation has the advantages of simple process, low energy consumption, small environmental pollution and the like.

Drawings

FIG. 1 is a schematic diagram of a condensing unit comprising 8-stage condensing trays according to an embodiment of the present invention;

in the figure, 1-condensation device; 11-stage 1 condensation tray; 12-stage 2 condensing trays; 13-stage 3 condensate tray; 14-stage 4 condensation plate; 15-stage 5 condensation trays; 16-stage 6 condensing disc; 17-stage 7 condensation plate; 18-stage 8 condensing disc; 2-a heating device; 3-a crucible; 4-raw material manganese.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

To better illustrate the invention and to facilitate the understanding of the technical solutions thereof, typical but non-limiting examples of the invention are as follows:

example 1

The embodiment provides a method for purifying manganese metal by vacuum distillation, which comprises the following steps:

1kg of a commercially available electrolytic manganese product having a purity of 3N was placed in a crucible, and the crucible was placed under a vacuum of 10 degrees^-5Under the vacuum condition of Pa, sequentially carrying out heating treatment of primary heating, secondary heating and tertiary heating, specifically: heating from room temperature to 400 ℃ at a speed of 10 ℃/min for primary heating, and keeping the temperature for 30 min; heating to 400-1000 deg.C at 8 deg.C/min for second-stage heating; further heating to the target temperature of 1400 ℃ at the speed of 4 ℃/min, carrying out three-stage heating, and keeping the temperature for 150 min; collecting the distilled manganese vapor through a condensing device, and condensing to obtain metal manganese with the purity of 5N;

wherein the condensing device comprises an 8-stage condensing disc; the steam channel openings of the condensing discs are alternately stacked, as shown in FIG. 1, so that the metal steam generated by distillation moves outwards in an S shape in the condensing device; a condensation disc close to the raw material manganese is a 1 st-stage condensation disc 11, and the metal manganese obtained by condensation is positioned on a 3 rd-6 th-stage condensation disc; the condensation surface of the 1 st-stage condensation plate 11 is an inclined surface, no baffle is arranged at the edge, the condensation surfaces of the other condensation plates are flat surfaces, and baffles are arranged at the edges; the condensation surface of the 1 st-stage condensation plate is inclined by 10 degrees;

stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; and respectively carrying out acid washing on the manganese metal on the 3-6-level condensation plate for 5min by using a nitric acid solution with the concentration of 5 wt.%, respectively characterizing and weighing after drying, wherein the total mass of the manganese metal is 835.6g, and the calculated yield is 83.56%.

Aiming at the analysis of the content of the impurity elements, C, H, O, N four gas elements are detected by a gas analyzer of LECO company in America, the rest impurity elements are detected by a Glow Discharge Mass Spectrometer (GDMS), the detection results of the content of the impurity elements are summarized in Table 1, wherein the sum of the mass of Se, Pb, Zn, Mg, Al, Si, Ni, Fe, Cr, S, Cl and Mn is 100%, and the purity of the metal manganese is not specifically listed; aiming at the analysis of the quantity of the non-metallic insoluble inclusions, an LPC-8D insoluble liquid particle analyzer is adopted to detect the quantity of the non-metallic insoluble inclusions with the particle size larger than 1.3 mu m in 1g of the metal manganese, and specific detection results are summarized in a table 2.

TABLE 1

TABLE 2

As can be seen from tables 1 and 2, the purity of the manganese metal prepared in the embodiment is 5N, the total impurity content in the manganese metal measured by GDMS is less than 10ppm, the total impurity content of gas elements is less than 50ppm, and the number of non-metallic insoluble inclusions with the grain diameter of more than 1.3 μm in each 1g of manganese metal is less than 3000, so that the requirements of the raw materials of the semiconductor target material are met.

Example 2

The embodiment provides a method for purifying manganese metal by vacuum distillation, which comprises the following steps:

1kg of a commercially available electrolytic manganese product having a purity of 3N was placed in a crucible, and the crucible was placed under a vacuum of 10 degrees^-1Pa vacuum stripUnder the piece, carry out one-level intensification, second grade intensification and the third grade heating-up's heat treatment in proper order, specifically do: heating from room temperature to 400 ℃ at a speed of 10 ℃/min for first-stage heating, and keeping the temperature for 50 min; heating to 400-1000 deg.C at 10 deg.C/min for second-stage heating; further heating to the target temperature of 1300 ℃ at the speed of 3 ℃/min, carrying out three-stage heating, and keeping the temperature for 90 min; collecting the distilled manganese vapor through a condensing device, and condensing to obtain metal manganese with the purity of 4N 8;

wherein the condensing device comprises an 8-stage condensing disc; the steam channel openings of the condensing discs are alternately stacked, so that the metal steam generated by distillation moves outwards in an S shape in the condensing device; a condensation disc close to the raw material manganese is a grade 1 condensation disc, and the metal manganese obtained by condensation is positioned on a grade 3-6 condensation disc; the condensation surface of the 1 st-stage condensation plate is an inclined surface, the edge of the condensation surface is not provided with a baffle, the condensation surfaces of the other condensation plates are flat, and the edges of the condensation surfaces are provided with baffles; the condensing surface of the 1 st-stage condensing disc is inclined by 15 degrees;

stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; and respectively carrying out acid washing on the manganese metal on the 3 rd-6 th-level condensation plate for 9min by using a nitric acid solution with the concentration of 3.4 wt.%, respectively characterizing and weighing after drying, wherein the total mass of the manganese metal is 733.3g, and the calculated yield is 73.33%.

Aiming at the analysis of the content of the impurity elements, C, H, O, N four gas elements are detected by a gas analyzer of LECO company in America, the rest impurity elements are detected by a Glow Discharge Mass Spectrometer (GDMS), the detection results of the content of the impurity elements are summarized in a table 3, wherein the sum of the mass of Se, Pb, Zn, Mg, Al, Si, Ni, Fe, Cr, S, Cl and Mn is 100%, and the purity of the metal manganese is not specifically listed; aiming at the analysis of the quantity of the non-metallic insoluble inclusions, an LPC-8D insoluble liquid particle analyzer is adopted to detect the quantity of the non-metallic insoluble inclusions with the particle size larger than 1.3 mu m in 1g of the metal manganese, and specific detection results are summarized in Table 4.

TABLE 3

TABLE 4

As can be seen from tables 3 and 4, the purity of the manganese metal prepared by the embodiment is 4N8, the total impurity content in the manganese metal measured by GDMS is less than 20ppm, the total impurity content of gas elements is less than 100ppm, and the number of non-metallic insoluble inclusions with the grain diameter of more than 1.3 μm in each 1g of manganese metal is less than 5000, so that the requirements of the raw materials of the semiconductor target material are met.

Example 3

The embodiment provides a method for purifying manganese metal by vacuum distillation, which comprises the following steps:

1kg of a commercially available electrolytic manganese product having a purity of 2N was placed in a crucible and then placed under a vacuum of 10^-3Under the vacuum condition of Pa, sequentially carrying out heating treatment of primary heating, secondary heating and tertiary heating, specifically: heating from room temperature to 450 deg.C at 8 deg.C/min for first-stage heating, and maintaining for 60 min; heating to 450-1100 deg.C at 5 deg.C/min for second-stage heating; further heating to the target temperature of 1300 ℃ at the speed of 3 ℃/min, carrying out three-stage heating, and keeping the temperature for 120 min; collecting the distilled manganese vapor through a condensing device, and condensing to obtain metal manganese with the purity of 4N 6;

wherein the condensing device comprises an 8-stage condensing disc; the steam channel openings of the condensing discs are alternately stacked, so that the metal steam generated by distillation moves outwards in an S shape in the condensing device; a condensation disc close to the raw material manganese is a grade 1 condensation disc, and the metal manganese obtained by condensation is positioned on a grade 3-6 condensation disc; the condensation surface of the 1 st-stage condensation plate is an inclined surface, the edge of the condensation surface is not provided with a baffle, the condensation surfaces of the other condensation plates are flat, and the edges of the condensation surfaces are provided with baffles; the condensation surface of the 1 st-stage condensation plate is inclined by 12 degrees;

stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; and respectively carrying out acid washing on the manganese metal on the 3 rd-6 th-level condensation plate for 10min by using a nitric acid solution with the concentration of 1 wt.%, and respectively characterizing and weighing after drying, wherein the total mass of the manganese metal is 786.1g, and the calculated yield is 78.61%.

Aiming at the analysis of the content of the impurity elements, C, H, O, N four gas elements are detected by a gas analyzer of LECO company in America, the rest impurity elements are detected by a Glow Discharge Mass Spectrometer (GDMS), the detection results of the content of the impurity elements are summarized in a table 5, wherein the sum of the mass of Se, Pb, Zn, Mg, Al, Si, Ni, Fe, Cr, S, Cl and Mn is 100%, and the purity of the metal manganese is not specifically listed; aiming at the analysis of the quantity of the non-metallic insoluble inclusions, an LPC-8D insoluble liquid particle analyzer is adopted to detect the quantity of the non-metallic insoluble inclusions with the particle size larger than 1.3 mu m in 1g of the metal manganese, and specific detection results are summarized in Table 6.

TABLE 5

TABLE 6

As can be seen from tables 5 and 6, the purity of the manganese metal prepared in this example is 4N6, the total impurity content in the manganese metal measured by GDMS is less than 40ppm, the total impurity content of gas elements is less than 100ppm, and the number of non-metallic insoluble inclusions with the grain size of more than 1.3 μm per 1g of manganese metal is less than 5000, which meets the requirements of the semiconductor target material.

Example 4

This example provides a method for purifying manganese metal by vacuum distillation, which is described with reference to example 1, except that: the condensing device comprises 6-stage condensing discs, and the steam channel openings of the condensing discs are alternately stacked, so that metal steam generated by distillation moves outwards in an S shape in the condensing device; and the condensation disc close to the raw material manganese is a grade 1 condensation disc, and the metal manganese obtained by condensation is positioned on the grade 3-4 condensation disc.

Stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; after gathering the manganese metal on the 3 rd-4 th-level condensation plate, carrying out acid washing for 5min by using a nitric acid solution with the concentration of 5 wt.%, weighing the total mass of the manganese metal to be 372.3g after drying, and calculating the yield to be 37.23%.

The purity of the manganese metal prepared by the embodiment is 4N5, the total impurity content in the manganese metal measured by GDMS is less than 50ppm, the total impurity content of gas elements is less than 100ppm, and the number of non-metal insoluble inclusions with the grain diameter of more than 1.3 mu m in each 1g of manganese metal is less than 5000, so that the requirement of the semiconductor target material is met, but the yield is reduced to 37.23%.

Example 5

This example provides a method for purifying manganese metal by vacuum distillation, which is described with reference to example 1, except that: the acid washing by using a nitric acid solution with the concentration of 5 wt.% is omitted, the manganese metal on the 3 rd-6 th-level condensation plate is directly gathered, the total mass of the manganese metal is weighed to be 853.6g, and the calculated yield is 85.36%.

The purity of the manganese metal prepared by the embodiment is 4N, the total content of impurities in the manganese metal measured by GDMS is less than 100ppm, the total content of gaseous element impurities is 105ppm, and the number of non-metallic insoluble inclusions with a particle size of more than 1.3 μm per 1g of manganese metal is 7253, which does not meet the requirements of semiconductor target raw materials, which indicates that the condensed manganese metal needs to be pickled to remove the impurities deposited on the manganese metal in the temperature raising and reducing stages.

Comparative example 1

The present comparative example provides a method for purifying manganese metal by vacuum distillation as described with reference to example 1, except that: the degree of vacuum under vacuum was 5 Pa.

Stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; after gathering the manganese metal on the 3 rd-6 th-level condensation plate, carrying out acid washing for 5min by using a nitric acid solution with the concentration of 5 wt.%, weighing the total mass of the manganese metal to be 804.7g after drying, and calculating the yield to be 80.47%.

The purity of the manganese metal prepared by the comparative example is 4N5, the total content of impurities in the manganese metal measured by GDMS is less than 50ppm, but because the vacuum degree is low, a large amount of air remains in a vacuum distillation system, the content of C, H, O, N four gas elements in the condensed manganese metal is greatly increased, the total content of the gas element impurities is up to 518ppm, the number of nonmetallic insoluble inclusions with the particle size of more than 1.3 mu m in each 1g of the manganese metal is up to 16509, the requirements of semiconductor target raw materials are not met, and because the vacuum degree is low, the actual vapor pressure of metal vapor is reduced, so that the total mass of the manganese metal obtained in the same process time as that of the embodiment 1 is slightly reduced, and the yield is reduced to 80.47%.

Comparative example 2

The present comparative example provides a method for purifying manganese metal by vacuum distillation as described with reference to example 1, except that: the target temperature of the third temperature rise is 1100 ℃.

Stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; after the manganese metal on the 3 rd-6 th-level condensation plate is collected, the manganese metal is pickled for 5min by using a nitric acid solution with the concentration of 5 wt.%, the total mass of the manganese metal is weighed to be 263.9g after the manganese metal is dried, and the calculated yield is 26.39%.

The purity of the metal manganese prepared by the comparative example is 3N5, the total impurity content of the metal manganese measured by GDMS is 500ppm, the sublimation temperature is too low, low-melting-point metal is deposited on No. 3-6, so that the manganese purity is reduced, the manganese sublimation is insufficient, the metal manganese yield is extremely low, the contents of C, H, O, N four gas elements in the metal manganese obtained by condensation are greatly increased, the total gas element impurity content is 367ppm, the number of non-metal insoluble inclusions with the particle size of more than 1.3 mu m in each 1g of the metal manganese is 13096, and the requirements of semiconductor target raw materials are not met.

Comparative example 3

The present comparative example provides a method for purifying manganese metal by vacuum distillation as described with reference to example 1, except that: the target temperature of the third temperature rise is 1500 ℃.

Stopping heating and cooling after the vacuum distillation purification is finished; introducing argon as a protective gas during the cooling period; after the manganese metal on the 3 rd-6 th-level condensation plate is collected, the manganese metal is pickled for 5min by using a nitric acid solution with the concentration of 5 wt.%, the total mass of the manganese metal is weighed to be 438.2g after the manganese metal is dried, and the calculated yield is 43.82%.

The purity of the metal manganese prepared by the comparative example is 3N6, the total impurity content in the metal manganese measured by GDMS is 400ppm, high-melting-point metal is deposited in a manganese deposition area due to overhigh distillation temperature, the manganese purity is insufficient, the yield is low due to overhigh temperature and partial manganese volatilization, the gas elements with the contents of C, H, O, N four gas elements in the metal manganese obtained by condensation are 218ppm, the number of non-metal insoluble inclusions with the particle size of more than 1.3 mu m in each 1g of the metal manganese is 13927, and the requirement of a semiconductor target material is not met.

In summary, the invention provides a method for purifying manganese metal by vacuum distillation, which comprises the steps of heating a raw material manganese under a vacuum condition, collecting distilled manganese steam by a condensing device, and condensing to obtain manganese metal; wherein the vacuum degree required for strictly controlling the vacuum condition is 10^-5-1Pa, and the target temperature of the heating is 1250-. The method adopts a vacuum distillation process to purify the manganese metal, not only can purify the manganese metal with the purity of 4N5-5N from the manganese raw material sold in the market, the total content of impurities in the manganese metal measured by GDMS is less than 50ppm, but also the total content of gas element impurities is less than 100ppm, the number of non-metal insoluble inclusions with the grain diameter of more than 1.3 mu m in each 1g of the manganese metal is less than 5000, the requirements of the raw material of the semiconductor target material are met, and the method also has the advantages of simple process, low energy consumption, small environmental pollution and the like.

The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.