JP2006201159A - Method of analyzing quality of nonferrous metal and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of analyzing a quality of a nonferrous metal such as a high purity copper excellent in the analysis accuracy and applied to a process control and a quality control. <P>SOLUTION: The method determines the quality of the nonferrous metal based on a determination expression y=[A]x+b within a target range of the quantity of an insoluble residual of the nonferrous metal. x is the quantity of the insoluble residual of the nonferrous metal. y is the quantity of an interfused refractory lining component contained in the residual. [A] and b are a coefficient and a constant defined in response to the nonferrous metal. In XY coordinate system, the quality of the nonferrous metal is determined from a fact that an analysis value is included within a range from a boundary indicated by the preset determination expression y=[A]x+b1 to a boundary indicated by the preset determination expression y=[A]x+b2. Alternately, the method determines the quality of the nonferrous metal by approximating at least two or more analytical values by the linear determination expression y=[A]x+b. x is the quantity of the insoluble residual of the nonferrous metal. y is the quantity of the interfused refractory lining component. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method for determining the quality of a non-ferrous metal and a manufacturing method using the determination method. According to the quality determination method of the present invention, non-ferrous metals such as high-purity copper can be applied to process management and quality control of non-ferrous metal products with excellent analysis accuracy based on the amount of residual insoluble matter contained. This is a method for determining the quality.

Conventionally, impurities contained in high-purity metals and alloys are analyzed by instrumental analysis such as SEM, or by dissolving a sample in mineral acid such as nitric acid or hydrochloric acid, and depending on the element and concentration to be measured, lCP, ICP-MS, FL- A wet analysis in which measurement is performed by AAS or the like is common. However, since the refractory elements such as carbon, aluminum, titanium, and zircon oxides contained as impurities become insoluble residues, the concentration cannot be accurately evaluated by analysis using these conventional methods. In addition, products such as sputtering targets and foils processed using 6N grade ultra-high purity metal as a raw material contain the insoluble residue as ultrafine particles, which causes defective products. For such insoluble residues, conventionally, the amount of the residue was obtained by visual observation with a microscope or the like. However, for local observation, analysis by visual observation or the like has low analysis accuracy, and SEM or the like. There is no evaluation means other than measurement by instrument analysis, and it cannot be reflected in process control and quality control.

Specifically, for example, the following method is conventionally known as a method for analyzing non-ferrous metal-containing materials. That is, after sampling the non-ferrous metal and polishing the obtained granular sample, analyze the form of the mineral containing the optical properties by reflected light and calculate the area of the mineral and convert it into a volume, This is a method for calculating the constituent element concentration of the mineral (Patent Document 1).
JP 2000-28604 A

The conventional analysis method has a problem that it takes time to polish the sample and the analysis accuracy is low because the analysis is performed based on the area of the mineral appearing on the surface. The present invention solves the above problems in conventional analysis methods, and provides a quality determination method that is excellent in analysis accuracy and can be applied to process control and quality control for non-ferrous metals such as high-purity copper. It is.

The present invention is a method for determining the quality of a non-ferrous metal having the following configuration.
(1) Within the target value range of the insoluble residue amount of the non-ferrous metal, a judgment formula y = [A] x + b (where [ A] and b are each a coefficient and a constant determined according to the non-ferrous metal), and the quality of the non-ferrous metal is determined.
(2) In the XY coordinates, within a target value range of the insoluble residue amount, within a range from a boundary indicated by a predetermined judgment formula y = [A] x + b1 to a boundary indicated by y = [A] x + b2. The quality determination method according to (1) above, wherein the quality of the nonferrous metal is determined by including the analysis value.
(3) In the XY coordinates, for the insoluble residue amount x of the non-ferrous metal and the furnace material component mixing amount y, at least two or more analytical values are within the target value range of the insoluble residue amount, and the judgment formula y = [ A] The quality determination method according to (1) above, wherein the quality of the non-ferrous metal is determined by being approximated to a straight line of x + b.
(4) The non-ferrous metal is Cu, Pb, Ni, Co, Sn, In, Sb, Bi, Te, Al, Ti, Zn, or an alloy thereof, and the furnace material component y is the amount of carbon and the insoluble residue. The quality determination method according to any one of (1) to (3), wherein the amount x is a total amount of insoluble matter.
(5) The quality determination method according to any one of (1) to (4) above, wherein the non-ferrous metal is a high-purity metal used as a target, foil, strip, or contact material.
(6) The non-ferrous metal insoluble residue amount x and the furnace material component amount y contained in the residue are used to determine the quality of the non-ferrous metal, and the residue amount x and the furnace material component mixing amount y The manufacturing method of the nonferrous metal which adjusts the conditions of a melting process based on.

The present invention is a method for determining the quality of a non-ferrous metal that has undergone a melting step, and within the target value range of the insoluble residue contained in the non-ferrous metal, the amount of insoluble residue x and the mixing of furnace material components contained in the residue And determining the quality of the non-ferrous metal based on a determination formula y = [A] x + b (wherein [A] and b are coefficients and constants determined according to the non-ferrous metal, respectively). This is a quality determination method.

Non-ferrous metals that have undergone a melting process are non-ferrous metals that have undergone a melting process in various melting furnaces in smelting and refining processes, such as high-purity copper and high-purity lead, or alloys thereof. is there. In the melting step, a furnace material component such as a melting furnace may be slightly mixed into the nonferrous metal. For example, high-purity copper, which is the raw material of the target material, is melted and refined using a carbon refining furnace in order to increase the purity to 6N grade. Mixed in. This carbon exists as fine insoluble matter (particles) in high purity copper.

Moreover, the cover material which covers a melting furnace and the material component of the equipment around a furnace may mix. For example, alumina derived from a lid covering the furnace, titania, zirconia derived from a refractory material around the furnace, or the like may be dissolved in a non-ferrous metal.

If insoluble materials such as particles are contained in the non-ferrous metal or a solid solution is present, it may cause a product defect. For example, if fine carbon particles are contained in high-purity copper, it will cause product defects when used as a target material. To reduce the amount of these impurities, the manufactured non-ferrous metal products Quality judgment is performed.

Usually, for example, when a non-ferrous metal sample Ag is dissolved in nitric acid or the like and the amount of acid-insoluble residue generated at this time is Bg, an allowable amount of acid-insoluble residue (Bg) is set. Although the quality of non-ferrous metals is determined, simply measuring the amount of residue does not reveal the components of impurities and the cause of their incorporation, and sufficient information for improving the quality cannot be obtained.

The present invention analyzes not only the amount of undissolved residue but also the residue component of the non-ferrous metal sample, for example, reveals the mixing of carbon, which is a furnace material component of the melting furnace, This is a method for determining the quality based on the amount of furnace material components such as carbon contained in the insoluble matter. In the present invention, the amount of insoluble residue is the amount of residue mainly composed of components insoluble in acids such as carbon, alumina, zirconia, etc. when non-ferrous metals are dissolved in nitric acid, etc. The material component mixing amount is the content of the furnace material component contained in the insoluble residue.

In the determination method of the present invention, the determination formula y = [A] based on the insoluble residue amount x and the furnace material component mixing amount y included in the residue within the target value range of the insoluble residue amount included in the nonferrous metal. This is a method for determining the quality of a non-ferrous metal based on x + b (where [A] and b are coefficients and constants determined according to the non-ferrous metal, respectively). Specifically, for example, for high-purity copper or high-purity lead, y in the above judgment formula is the amount of carbon of the furnace material component, and the insoluble residual amount x is the total amount of other insoluble materials including carbon. The coefficient [A] and the constant b in the determination formula are determined according to the type and application of the nonferrous metal. Further, the determination formula is a straight line approximated by, for example, the least square method based on a plurality of analysis data.

The allowable range of quality is determined by a constant b, for example. In the XY coordinates of FIG. 1, within the target value range of the insoluble residue amount, within a range from a boundary indicated by a predetermined judgment formula y = [A] x + b1 to a boundary indicated by y = [A] x + b2. The quality of the non-ferrous metal is determined by including the analysis value.

Specifically, for example, in the XY coordinates of FIG. 1, the coefficient [A] determined based on the type and use of the non-ferrous metal with respect to the insoluble residue amount x and the furnace material component mixing amount y of the non-ferrous metal sample , An allowable range M defined by a straight line indicated by a judgment formula y = [A] x + b1, y = [A] x + b2 each including constants b1 and b2, and an insoluble residue amount x obtained for each sample, The analytical value of the furnace material component mixing amount y is plotted, and this point is defined as an acceptable quality within the allowable range M within the target value range of the insoluble residue amount x. In the example of FIG. 1, among the analysis values S1 to S4 obtained for each of the samples No. 1 to No. 4, the analysis values S1 and S2 of the samples No. 1 and No. 2 are included in the allowable range M. Since the analysis values S3 and S4 of samples No. 3 and No. 4 are out of the allowable range M, they are rejected.

The determination method of the present invention is not limited to a method of predetermining the acceptable range of quality, and at least two or more analysis values of the insoluble residue amount x of the non-ferrous metal and the furnace material component mixing amount y are not in the XY coordinates. The quality of the non-ferrous metal can be determined by approximating a straight line of the determination formula y = [A] x + b within the target value range of the dissolved residue amount.

Specifically, as shown in Example 1 described later, the points where the analysis values of the insoluble residue amount x and the furnace material component mixing amount y measured for each sample are plotted on the XY coordinates are y = [A] x + b Since each analysis value point is located in the vicinity of this straight line, all of these samples can be judged as acceptable quality within the target value range of the insoluble residue.

When the non-ferrous metal whose quality is determined by the method of the present invention is processed into, for example, a target material or a metal foil and used, those that are determined to be acceptable quality produce almost no defective products, while Almost all determined items are defective, and the determination method of the present invention is highly reliable.

The determination method of the present invention is such that, for example, for each non-ferrous metal such as Cu, Pb, Ni, Co, Sn, In, Sb, Bi, Te, Al, Ti, Zn, or an alloy thereof, the furnace material component y is a carbon content. The insoluble residual amount x can be widely applied as the total amount of insoluble matter. Specifically, it can be suitably applied to high-purity metals used as materials for targets, foils, strips, and contacts.

The method of the present invention is not limited to determining the quality of the produced non-ferrous metal, but based on the non-soluble residue amount x of the non-ferrous metal measured for the quality determination and the furnace material component amount y contained in the residue. Thus, it can be used as an index for adjusting the melting process condition of the non-ferrous metal.

According to the determination method of the present invention, the quality of the non-ferrous metal can be accurately determined based on the amount of the furnace material components mixed and the undissolved remaining amount, so that it is applied to process management and quality control of the non-ferrous metal product. be able to. Specifically, for example, for high-purity copper and high-purity lead used as materials for targets and metal foils, the amount of generated particles is reduced for target materials based on component analysis of insoluble residues, and copper foil In the case of a lead foil or the like, it is possible to reduce rolling defects due to foreign matter contamination.

Further, by grasping the component concentration of the insoluble residue by ICP-MS analysis, when an abnormality occurs in the product process, it becomes easy to identify the factor element. Furthermore, quality can be controlled to a certain quality by standardizing the amount of insoluble residue. In the conventional insoluble substance analysis in non-ferrous metals, the exact component concentration is not grasped, and it is difficult to apply to process management and quality control of non-ferrous metal products.

In the determination method of the present invention, for example, high purity copper is analyzed according to the following procedure.
(1) The sample is etched with nitric acid to remove adhering impurities near the surface.
(2) Weigh 100 g of the etched sample.
(3) Add nitric acid to the sample and dissolve by heating.
(4) After cooling to room temperature, filter with a commercially available filter and collect the residue.
(5) Carbon analysis uses the filter which collected the residue by repeating the above (1) to (4) as a sample.
(6) Repeat steps (1) to (4) above for the impurity elements other than carbon, and use the filter that collects the residue as a sample, and perform pretreatment according to the following procedure.
(7) The filter collecting the residue is decomposed with concentrated sulfuric acid.
(8) Add nitric acid and hydrogen peroxide to the sample to decompose the residue and organic matter in the filter.
(9) Treat with white smoke until the residual sulfuric acid content is solidified and evaporate.
(10) Extract the element to be measured with ultrapure water to which nitric acid has been added.
(11) After extraction and concentration, the volume is adjusted to 2 ml, and the components are measured by ICP-MS.
In addition, the sample is used after being cut into chips so as to be easily dissolved. The filter is preferably a polycarbonate filter (pore size 0.4 μm, 47 mmφ) for IPC-MS analysis, and a glass filter (pore size 0.6 μm, 47 mmφ) for carbon analysis.

Examples of the present invention are shown below.
[Example 1]
For a plurality of samples of high-purity copper (6N copper), the carbon content y derived from the furnace material components and the insoluble residue amount x were measured according to the above analysis procedure, and the results shown in FIG. 2 were obtained. Those included in the range in the vicinity of the straight line y = [A] x + b ([A] = 0.4437, b = 8.4906) approximated by the least squares method (those located on or near the straight line: ◆ mark) are target materials When processed and used, all were normal products. On the other hand, when products not belonging to this range (□ mark, Δ mark) were used, all were defective. When the measured values are plotted and approximated by a straight line in this way, normal products are distributed within a certain range of the notation straight line, and abnormal products are distributed beyond that range. Therefore, a plot in which the amount of carbon is significantly smaller or larger than the amount of residue is considered to be caused by segregation of carbon in the sample, and the result can be fed back to product quality control.

[Example 2]
For a plurality of samples of high-purity copper (6N copper), according to the above analysis procedure, the aluminum content y derived from the lid material component of the melting furnace and the insoluble residue amount x were measured, and the results shown in FIG. 3 were obtained. It was. Among these, those belonging to the range defined by the straight line y = [A] x + b1 and the straight line y = [A] x + b2 approximated by the least square method (marked with ♦) are processed into a target material and used. As a result, all were normal products. On the other hand, when products not belonging to this range (□ mark, Δ mark) were used, all were defective.

Example 3
For a plurality of samples of high-purity lead (4N lead), the carbon content y and the insoluble residue amount x derived from the furnace material components were measured according to the above analysis procedure, and the results shown in FIG. 4 were obtained. Those included in the range in the vicinity of the straight line y = [A] x + b ([A] = 0.837, b = 2.7707) approximated by the method of least squares (those located on or near the straight line: ◆ mark) are target materials When processed and used, all were normal products. On the other hand, when products not belonging to this range (□ mark, Δ mark) were used, all were defective.

Example 4
For purified zinc, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 5 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 5
For purified titanium, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 6 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 6
For purified aluminum, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 7 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 7
For purified tellurium, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analytical procedure, and the results shown in FIG. 8 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 8
For purified bismuth, the amount of insoluble residue x and the amount of carbon y in the residue were measured according to the above analytical procedure, and the results shown in FIG. 9 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 9
For the purified antimony, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 10 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 10
For purified indium, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 11 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 11
For the purified tin, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 12 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 12
For the purified cobalt, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 13 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

Example 13
For the purified nickel, the insoluble residue amount x and the carbon amount y in the residue were measured according to the above analysis procedure, and the results shown in FIG. 14 were obtained. The straight line of the judgment formula determined by the least square method is shown in the figure. In the figure, the range marked with ♦ indicates acceptable quality for general applications.

The graph which shows the determination method of this invention based on the insoluble residue amount x and the furnace material component mixing amount y about a nonferrous metal. The graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues about the high purity copper of Example 1. The graph of the analytical value which shows the determination method of this invention based on the amount of aluminum and the amount of insoluble residues about the high purity copper of Example 2. The graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues about the high purity lead of Example 3. About the zinc of Example 4, the graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues. About the titanium of Example 5, the graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues. About the aluminum of Example 6, the graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues. The graph of the analytical value which shows the determination method of this invention about the tellurium of Example 7 based on the amount of carbon and the amount of insoluble residues. The graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues about the bismuth of Example 8. About the antimony of Example 9, the graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues. The graph of the analytical value which shows the determination method of this invention about the indium of Example 10 based on the amount of carbon and the amount of insoluble residues. About the tin of Example 11, the graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues. The cobalt of Example 12 is a graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues. The nickel of Example 13 is a graph of the analytical value which shows the determination method of this invention based on the amount of carbon and the amount of insoluble residues.

Claims (6)

Within the target value range of the insoluble residue amount of the non-ferrous metal, the judgment formula y = [A] x + b (in the formula, [A], with the insoluble residue amount x and the furnace material component mixing amount y contained in the residue) b is a quality determination method, wherein the quality of the nonferrous metal is determined based on a coefficient and a constant determined in accordance with the nonferrous metal.
In the XY coordinates, within the target value range of the insoluble residue amount, the analysis value is within the range from the boundary indicated by the predetermined judgment formula y = [A] x + b1 to the boundary indicated by y = [A] x + b2. The quality determination method according to claim 1, wherein the quality of the non-ferrous metal is determined by being included.
In the XY coordinates, at least two or more analysis values of the non-ferrous metal insoluble residue amount x and the furnace material component mixing amount y are within the target value range of the insoluble residue amount, and the determination formula y = [A] x + b The quality determination method according to claim 1, wherein the quality of the non-ferrous metal is determined by being approximated by a straight line.
The non-ferrous metal is each metal of Cu, Pb, Ni, Co, Sn, In, Sb, Bi, Te, Al, Ti, Zn or an alloy thereof, the furnace material component y is the carbon amount, and the insoluble residual amount x is The quality determination method according to any one of claims 1 to 3, which is a total amount of insoluble matter.
The quality determination method according to any one of claims 1 to 4, wherein the non-ferrous metal is a high-purity metal used as a target, foil, strip, or contact material.
The non-ferrous metal insoluble residue amount x and the furnace material component amount y contained in the residue are used to determine the quality of the non-ferrous metal and melt based on the residue amount x and the furnace material component mixing amount y. A method for producing a non-ferrous metal in which process conditions are adjusted.

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