Standard substance for pure zinc spectral analysis and preparation method thereof

Abstract

The invention provides a standard substance for pure zinc spectral analysis and a preparation method thereof, and relates to the technical field of analysis and detection. The standard substance for the pure zinc spectral analysis comprises the following elements: 0.001-0.003% of Pb; 0.001 to 0.003 percent of Cd (cadmium); fe: 0.0005 to 0.003%; cu: 0.0005 to 0.002%; sn: 0.0005% to 0.0015%; 0.0005 to 0.0025 percent of Al (aluminum); 0.0005 to 0.003 percent of Ni (nickel); 0.0005 to 0.0025 percent of Bi (bismuth); 0.0005 to 0.0025 percent of Sb (Sb); mg: 0.0001% to 0.0025%; and the balance of Zn. The standard substance for pure zinc spectrum analysis is excellent in uniformity and stability, and can be used for quality evaluation, analysis instrument calibration, analysis method evaluation, magnitude transmission, traceability and the like.

Description

Technical Field

[0001] The invention relates to the technical field of analysis and detection, and in particular to a standard substance for pure zinc spectrum analysis and a preparation method thereof. Background Art

[0002] Zinc is an important raw material for nonferrous metals. Currently, zinc ranks third in nonferrous metal consumption, second only to aluminum and copper. Zinc metal has good rolling resistance, wear resistance and corrosion resistance, and can be made into alloys with better physical and chemical properties with a variety of metals. In recent years, the production scale of zinc has continued to expand, product competition has become more intense, and users have higher and higher requirements for product quality.

[0003] The widespread application of high-performance spark source atomic emission spectrometry analysis technology has made the analysis of pure zinc products faster and more accurate. Among them, standard substances for pure zinc spectral analysis play a vital role. They are usually used to calibrate instruments, verify analytical methods and perform quality control.

[0004] The uniformity and stability of pure zinc standard materials are crucial to the accuracy and reliability of measurement results. However, due to factors such as preparation process and storage conditions, pure zinc standard materials on the market may have problems such as unreasonable chemical composition ratio, component segregation, and composition range that cannot meet actual needs.

[0005] In view of this, the present invention aims to develop a standard substance for pure zinc spectral analysis which has reasonable composition design, uniformity, stability and other aspects that meet the requirements. Summary of the invention

[0006] The present invention provides a pure zinc standard substance for spectral analysis and a preparation method thereof, so as to solve the defects of poor uniformity and stability of pure zinc standard substances in the prior art, thereby providing a pure zinc standard substance for spectral analysis that meets the standards, which can be used for quality evaluation, calibration of analytical instruments, evaluation of analytical methods, quantity value transfer and traceability, etc.

[0007] In the first aspect, the present invention provides a series of standard substances for pure zinc spectral analysis, wherein the elements in the standard substances are composed as follows: Pb: 0.001~0.003%; Cd: 0.001~0.003%; Fe: 0.0005~0.003%; Cu: 0.0005~0.002%; Sn: 0.0005~0.0015%; Al: 0.0005~0.0025%; Ni: 0.0005~0.003%; Bi: 0.0005~0.0025%; Sb: 0.0005~0.0025%; Mg: 0.0001~0.0025%; the balance is Zn.

[0008] In some embodiments of the present invention, the elements in the standard substance are composed as follows: Pb: 0.001~0.002%; Cd: 0.001~0.002%; Fe: 0.0005~0.0015%; Cu: 0.001~0.002%; Sn: 0.0008~0.0015%; Al: 0.0005~0.001%; ​​Ni: 0.0005~0.001%; ​​Bi: 0.0005~0.0015%; Sb: 0.0005~0.0015%; Mg: 0.0001~0.0005%; the balance is Zn.

[0009] In some embodiments of the present invention, the elements in the standard substance are composed as follows: Pb: 0.001~0.002%; Cd: 0.001~0.002%; Fe: 0.0005~0.001%; ​​Cu: 0.0005~0.0015%; Sn: 0.0005~0.0015%; Al: 0.001~0.002%; Ni: 0.0005~0.001%; ​​Bi: 0.0005~0.0015%; Sb: 0.0005~0.0015%; Mg: 0.0015~0.0025%; the balance is Zn.

[0010] In some embodiments of the present invention, the elements in the standard substance are composed as follows: Pb: 0.002~0.003%; Cd: 0.002~0.003%; Fe: 0.002~0.003%; Cu: 0.0008~0.0015%; Sn: 0.0008~0.0015%; Al: 0.0015~0.0025%; Ni: 0.002~0.003%; Bi: 0.0015~0.0025%; Sb: 0.0015~0.0025%; Mg: 0.0005~0.001%; ​​the balance is Zn.

[0011] In one embodiment of the present invention, the elements in the standard substance are composed as follows: Pb: 0.0015±0.0001%; ​​Cd: 0.0015±0.0001%; ​​Fe: 0.00092±0.00008%; Cu: 0.0012±0.0001%; ​​Sn: 0.0011±0.0001%; ​​Al: 0.00071±0.00009%; Ni: 0.00063±0.00005%; Bi: 0.00096±0.00007%; Sb: 0.0012±0.0001%; ​​Mg: 0.0003±0.0001%; ​​the balance is Zn.

[0012] In one embodiment of the present invention, the elements in the standard substance are composed as follows: Pb: 0.0016±0.0001%; ​​Cd: 0.0015±0.0001%; ​​Fe: 0.00081±0.00006%; Cu: 0.0012±0.0001%; ​​Sn: 0.0011±0.0001%; ​​Al: 0.0015±0.0002%; Ni: 0.00057±0.00004%; Bi: 0.00096±0.00005%; Sb: 0.0011±0.0001%; ​​Mg: 0.002±0.0002%; the balance is Zn.

[0013] In one embodiment of the present invention, the elements in the standard substance are composed as follows: Pb: 0.0026±0.0002%; Cd: 0.0022±0.0001%; ​​Fe: 0.0025±0.0002%; Cu: 0.001±0.0001%; ​​Sn: 0.0012±0.0001%; ​​Al: 0.0021±0.0003%; Ni: 0.0023±0.0002%; Bi: 0.002±0.0002%; Sb: 0.0022±0.0002%; Mg: 0.00074±0.00008%; the balance is Zn.

[0014] In a second aspect, the present invention provides a standard substance for pure zinc spectral analysis, wherein the elements in the standard substance are composed as follows: Pb: 0.004~0.006%; Cd: 0.0015~0.0025%; Fe: 0.003~0.005%; Cu: 0.002~0.003%; Sn: 0.0005~0.001%; ​​Al: 0.005~0.01%; the balance is Zn; Or, Pb: 0.015~0.025%; Cd: 0.008~0.012%; Fe: 0.01~0.02%; Cu: 0.0015~0.0025%; Sn: 0.0005~0.0015%; Al: 0.002~0.004%; the balance is Zn.

[0015] In some embodiments of the present invention, the elements in the standard substance are composed as follows: Pb: 0.0048±0.0003%; Cd: 0.002±0.0001%; ​​Fe: 0.0038±0.0002%; Cu: 0.0022±0.0002%; Sn: 0.00069±0.00006%; Al: 0.0086±0.0008%; the balance is Zn; Or, Pb: 0.0196±0.0009%; Cd: 0.0093±0.0004%; Fe: 0.0165±0.0008%; Cu: 0.002±0.0002%; Sn: 0.00092±0.00006%; Al: 0.003±0.0003%; the balance is Zn.

[0016] In a third aspect, the present invention also provides a method for preparing the above-mentioned pure zinc standard substance for spectral analysis.

[0017] The preparation method provided by the present invention comprises the following steps: S1. According to the elemental composition of the standard substance, calculate and prepare various raw materials: including 0# zinc and intermediate alloys or pure metals of other metal elements; S2. Mix and melt various raw materials using a medium frequency induction furnace, wherein the melting temperature is 480-500°C; S3, casting the alloy liquid obtained by smelting in step S2 into an ingot, controlling the casting temperature at 460-480°C and the casting speed at 75-100 mm / min; performing a preliminary inspection of the ingot after obtaining the ingot; S4. Processing the ingots that have passed the initial inspection in step S3 into target specifications to obtain standard materials for pure zinc spectral analysis, and performing uniformity inspection, stability investigation, fixed value analysis and uncertainty assessment respectively, and then packaging the finished products.

[0018] Preferably, in step S1, the three elements of copper, iron and nickel are respectively made of copper-zinc alloy, zinc-iron alloy and zinc-nickel alloy as raw materials, and the remaining metal elements are made of pure metals.

[0019] Preferably, in step S2, the order of adding raw materials is: first mix copper-zinc alloy, zinc-iron alloy, zinc-nickel alloy, pure aluminum, pure antimony and 80% of 0# zinc, and after complete melting, add the remaining 0# zinc to cool the melt, and then add pure lead, pure cadmium, pure tin, pure bismuth and pure magnesium.

[0020] The invention provides a pure zinc standard substance for spectral analysis and a preparation method thereof. The invention obtains a pure zinc standard substance for spectral analysis with excellent uniformity and stability through reasonable component design and control of the preparation method. The standard substance complies with JJF 1006-1994 "Technical Specifications for Primary Standard Materials", is applicable to spark source atomic emission spectrometry analysis of Zn99.995, Zn99.99 and Zn99.95 grades in GB / T 470-2008 "Zinc Ingot", and can be used for quality evaluation, calibration of analytical instruments, evaluation of analytical methods, quantity value transfer and traceability, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a metallographic test piece of an ingot slice of SYD1001 provided in an embodiment of the present invention.

[0023] Figure 2 This is a metallographic test piece of an ingot slice of SYD1002 provided in an embodiment of the present invention.

[0024] Figure 3 This is a metallographic test piece of an ingot slice of SYD1003 provided in an embodiment of the present invention.

[0025] Figure 4 It is a metallographic test piece of an ingot slice of SYD1004 provided in an embodiment of the present invention.

[0026] Figure 5 This is a metallographic test piece of an ingot slice of SYD1005 provided in an embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the initial uniformity inspection.

[0028] Figure 7 It is a schematic diagram of uniformity test distribution. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0031] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific implementations", or "some specific implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0032] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0033] The main component of the standard material for pure zinc spectral analysis is zinc, and its purity is usually very high to ensure the accuracy of the analysis. The standard material also includes many other elements, and some of these elements are easy to segregate, volatilize, oxidize and burn. Therefore, the reasonable design of the element composition in the standard material is a necessary prerequisite for achieving the uniformity of the standard material.

[0034] The embodiment of the present invention provides a standard substance for pure zinc spectral analysis, and the elements in the standard substance are composed as follows: Pb: 0.001~0.003%; Cd: 0.001~0.003%; Fe: 0.0005~0.003%; Cu: 0.0005~0.002%; Sn: 0.0005~0.0015%; Al: 0.0005~0.0025%; Ni: 0.0005~0.003%; Bi: 0.0005~0.0025%; Sb: 0.0005~0.0025%; Mg: 0.0001~0.0025%; the balance is Zn.

[0035] The standard substance for pure zinc spectral analysis provided in an embodiment of the present invention is based on pure zinc ingot (0# zinc), and mainly adds the elements Pb, Cd, Fe, Cu, Sn, Al, Ni, Bi, Sb, and Mg. In order to avoid segregation and instability of the elements, the content range of each element is set within the above range through ratio calculation. Within this setting range, the uniformity and stability of the standard substance are better.

[0036] In order to obtain better uniformity and stability, as an optional embodiment, the composition of each element in the standard substance is as follows: Pb: 0.001~0.002%; Cd: 0.001~0.002%; Fe: 0.0005~0.0015%; Cu: 0.001~0.002%; Sn: 0.0008~0.0015%; Al: 0.0005~0.001%; ​​Ni: 0.0005~0.001%; ​​Bi: 0.0005~0.0015%; Sb: 0.0005~0.0015%; Mg: 0.0001~0.0005%; the balance is Zn.

[0037] Further preferably, the elements in the standard substance are composed as follows: Pb: 0.0015±0.0001%; ​​Cd: 0.0015±0.0001%; ​​Fe: 0.00092±0.00008%; Cu: 0.0012±0.0001%; ​​Sn: 0.0011±0.0001%; ​​Al: 0.00071±0.00009%; Ni: 0.00063±0.00005%; Bi: 0.00096±0.00007%; Sb: 0.0012±0.0001%; ​​Mg: 0.0003±0.0001%; ​​the balance is Zn.

[0038] As an optional embodiment, the elements in the standard substance are composed as follows: Pb: 0.001~0.002%; Cd: 0.001~0.002%; Fe: 0.0005~0.001%; ​​Cu: 0.0005~0.0015%; Sn: 0.0005~0.0015%; Al: 0.001~0.002%; Ni: 0.0005~0.001%; ​​Bi: 0.0005~0.0015%; Sb: 0.0005~0.0015%; Mg: 0.0015~0.0025%; the balance is Zn.

[0039] Further preferably, the elements in the standard substance are composed as follows: Pb: 0.0016±0.0001%; ​​Cd: 0.0015±0.0001%; ​​Fe: 0.00081±0.00006%; Cu: 0.0012±0.0001%; ​​Sn: 0.0011±0.0001%; ​​Al: 0.0015±0.0002%; Ni: 0.00057±0.00004%; Bi: 0.00096±0.00005%; Sb: 0.0011±0.0001%; ​​Mg: 0.002±0.0002%; the balance is Zn.

[0040] As an optional embodiment, the elements in the standard substance are composed as follows: Pb: 0.002~0.003%; Cd: 0.002~0.003%; Fe: 0.002~0.003%; Cu: 0.0008~0.0015%; Sn: 0.0008~0.0015%; Al: 0.0015~0.0025%; Ni: 0.002~0.003%; Bi: 0.0015~0.0025%; Sb: 0.0015~0.0025%; Mg: 0.0005~0.001%; ​​the balance is Zn.

[0041] Further preferably, the elements in the standard substance are composed as follows: Pb: 0.0026±0.0002%; Cd: 0.0022±0.0001%; ​​Fe: 0.0025±0.0002%; Cu: 0.001±0.0001%; ​​Sn: 0.0012±0.0001%; ​​Al: 0.0021±0.0003%; Ni: 0.0023±0.0002%; Bi: 0.002±0.0002%; Sb: 0.0022±0.0002%; Mg: 0.00074±0.00008%; the balance is Zn.

[0042] On the other hand, the present invention also uses pure zinc ingot (0# zinc) as a matrix and adds elements Pb, Cd, Fe, Cu, Sn, and Al to obtain a standard substance for pure zinc spectral analysis with excellent uniformity and stability.

[0043] As an optional embodiment, the elements in the standard substance are composed as follows: Pb: 0.004~0.006%; Cd: 0.0015~0.0025%; Fe: 0.003~0.005%; Cu: 0.002~0.003%; Sn: 0.0005~0.001%; ​​Al: 0.005~0.01%; the balance is Zn.

[0044] Further preferably, the elements in the standard substance are composed as follows: Pb: 0.0048±0.0003%; Cd: 0.002±0.0001%; ​​Fe: 0.0038±0.0002%; Cu: 0.0022±0.0002%; Sn: 0.00069±0.00006%; Al: 0.0086±0.0008%; the balance is Zn.

[0045] As an optional embodiment, the elements in the standard substance are composed as follows: Pb: 0.015~0.025%; Cd: 0.008~0.012%; Fe: 0.01~0.02%; Cu: 0.0015~0.0025%; Sn: 0.0005~0.0015%; Al: 0.002~0.004%; the balance is Zn.

[0046] Further preferably, the elements in the standard substance are composed as follows: Pb: 0.0196±0.0009%; Cd: 0.0093±0.0004%; Fe: 0.0165±0.0008%; Cu: 0.002±0.0002%; Sn: 0.00092±0.00006%; Al: 0.003±0.0003%; the balance is Zn.

[0047] The invention also provides a method for preparing the above-mentioned standard substance for pure zinc spectrum analysis.

[0048] In an embodiment of the present invention, the preparation method comprises the following steps: S1. According to the elemental composition of the standard substance, calculate and prepare various raw materials: including 0# zinc and intermediate alloys or pure metals of other metal elements; S2. Mix and melt various raw materials using a medium frequency induction furnace, wherein the melting temperature is 480-500°C; S3, casting the alloy liquid obtained by smelting in step S2 into an ingot, controlling the casting temperature at 460-480°C and the casting speed at 75-100 mm / min; performing a preliminary inspection of the ingot after obtaining the ingot; S4. Processing the ingots that have passed the initial inspection in step S3 into target specifications to obtain standard materials for pure zinc spectral analysis, and performing uniformity inspection, stability investigation, fixed value analysis and uncertainty assessment respectively, and then packaging the finished products.

[0049] In the above steps, the melting temperature needs to consider the dual effects of high melting point elements and easily oxidized volatile elements. If the temperature is too low, the metal will not melt fully and completely, and the alloying speed will be slow, resulting in uneven liquid phase composition. If the temperature is too high, the elements will be severely burned, which will seriously affect the expected chemical composition range. The present invention has been experimentally determined to be controlled at 480~500℃.

[0050] The casting temperature has a great influence on the uniformity of the standard material. If the temperature is too high, the cooling speed is slow, the liquid phase time is long, and the macro segregation is serious; if the temperature is too low, there will be segregation, poor solution fluidity, easy to have defects such as pores and inclusions, and poor ingot quality. The present invention has been experimentally determined that the temperature should be controlled at 460-480℃.

[0051] The casting speed directly affects the quality of the ingot. If the casting speed is too slow, the solidification time is short, the surface quality of the casting is poor, and defects such as pores and cracks are easily generated inside. If the casting speed is too fast, the solidification time is long, and elements such as lead and iron are easy to form segregation, making the ingot longitudinally uneven. After testing, the casting speed is preferably controlled at 75~100mm / min. The specification of the ingot mold in the embodiment of the present invention is Φ130×600mm, and the ingot length during casting is about 500~600mm.

[0052] Preferably, in step S1, the three elements of copper, iron and nickel are respectively made of copper-zinc alloy, zinc-iron alloy and zinc-nickel alloy as raw materials, and the remaining metal elements are made of pure metals.

[0053] Since copper, iron and nickel have relatively high melting points, they are added in the form of intermediate alloys, while the remaining aluminum, lead, cadmium, tin, bismuth, antimony and magnesium are pure metals. It is understandable that when preparing a standard material that does not contain the elements Ni, Bi, Sb and Mg, there is no need to add alloys or pure metals of these elements.

[0054] Preferably, in step S1, when 0# zinc is used, the content of elements already contained in 0# zinc is deducted during batching according to the raw material analysis report, so that the batching accuracy is strictly controlled.

[0055] Preferably, in step S2, the order of adding materials is: first mix copper-zinc alloy, zinc-iron alloy, zinc-nickel alloy, pure aluminum, pure antimony and 80% of 0# zinc, and after complete melting, add the remaining 0# zinc to cool the melt, and then add pure lead, pure cadmium, pure tin, pure bismuth and pure magnesium. It is understandable that when preparing a standard substance that does not contain the elements Ni, Bi, Sb and Mg, first mix copper-zinc alloy, zinc-iron alloy, pure aluminum and 80% of 0# zinc, and after complete melting, add the remaining 0# zinc to cool the melt, and then add pure lead, pure cadmium and pure tin. A reasonable order of adding materials is crucial to ensure that the alloy composition meets expectations.

[0056] In order to facilitate the understanding of the pure zinc standard substance for spectral analysis provided by the present invention, it is described below through specific examples.

[0057] The equipment used in the following embodiments include: a 200kW medium frequency induction furnace, a Φ130×600mm ingot mold, a sawing machine, a common lathe, and a spark source atomic emission spectrometer.

[0058] This embodiment provides 5 designed pure zinc standard substances for spectral analysis, with sample numbers SYD1001 to SYD1005, respectively. The composition designs and target uncertainties are shown in Tables 1 to 5.

[0059] Table 1 SYD1001 composition design and target uncertainty (ω / %) Table 2 SYD1002 composition design and target uncertainty (ω / %) Table 3 SYD1003 composition design and target uncertainty (ω / %) Table 4 SYD1004 composition design and target uncertainty (ω / %) Table 5 SYD1005 composition design and target uncertainty (ω / %) The preparation method of the above standard substances is as follows: S1. According to the elemental composition of the standard substances, various raw materials are calculated and prepared. The raw materials of SYD1001~SYD1003 are 0# zinc, copper-zinc alloy (Cu: 59%), zinc-iron alloy (Fe: 6%), zinc-nickel alloy (Ni: 10%), pure lead, pure cadmium, pure tin, pure aluminum, pure bismuth, pure antimony, and pure magnesium; the raw materials of SYD1004~SYD1005 are 0# zinc, copper-zinc alloy (Cu: 59%), zinc-iron alloy (Fe: 6%), pure lead, pure cadmium, pure tin, and pure aluminum; and according to the raw material analysis report of 0# zinc, the element content already contained in 0# zinc is deducted.

[0060] S2. Various raw materials are mixed and smelted in a medium frequency induction furnace, and the smelting temperature is 480~500℃. The mixing order of SYD1001~SYD1003 is 4 / 5 of 0# zinc, copper-zinc alloy (Cu: 59%), zinc-iron alloy (Fe: 6%), zinc-nickel alloy (Ni: 10%), pure aluminum, and pure antimony are charged into the furnace at one time; after the melting is complete, the remaining 0# zinc is added to cool the melt, and then pure lead, pure cadmium, pure tin, pure bismuth, and pure magnesium are added. The mixing order of SYD1004~SYD1005 is 4 / 5 of 0# zinc, copper-zinc alloy (Cu: 59%), zinc-iron alloy (Fe: 6%), and pure aluminum are charged into the furnace at one time; after the melting is complete, the remaining 0# zinc is added to cool the melt, and then pure lead, pure cadmium, and pure tin are added.

[0061] S3, casting the alloy liquid obtained by smelting in step S2 into ingots, the casting temperature is controlled at 460-480°C, and the casting speed is controlled at 75-100 mm / min; sequential casting is adopted, four Φ130 mm ingots are sequentially cast for each number, the ingot length is 500-600 mm, the riser at the head of the ingot is cut off by about 100-150 mm, the tail is cut off by about 50 mm, and the final length of the ingot is about 300-450 mm.

[0062] After obtaining the ingot, an initial inspection of the ingot is carried out.

[0063] S4. After the ingot that has passed the initial inspection in step S3 is processed into blocks, the edges are polished and chamfered, the surface is numbered, and the blocks are stored in a cool, dark storage room at room temperature. The specifications are Φ38*30mm, and they are packaged in hard square boxes and labeled to obtain standard substances for pure zinc spectral analysis. After uniformity inspection, stability inspection, fixed value analysis and uncertainty assessment are carried out respectively, the finished products are packaged.

[0064] The following is a detailed introduction to the initial inspection, uniformity test, stability test, constant value analysis and uncertainty assessment of ingots.

[0065] 1. Initial inspection of ingots 1.1 Preparation of ingot specimens The defects at both ends of the finished ingot were cut off by sawing machine, and then a test piece with a thickness of about 10mm to 15mm was taken from the head and bottom of each ingot, respectively, to obtain eight test pieces.

[0066] 1.2 Microstructure inspection of ingot slices Through low-power inspection of metallographic specimens, it is proved that the ingot structure is dense, uniform, and free of defects such as pores, looseness, and inclusions. One ingot slice is selected for each number as a diagram. The results are as follows: Figures 1 to 5 shown.

[0067] 1.3 Preliminary inspection of the uniformity of ingot samples The uniformity was initially inspected using a SPECTROLAB spark source atomic emission spectrometer. Pb, Cd, Fe, Cu, Sn, Al, and Mg elements were tested according to GB / T 26042-2010 "Analysis of Zinc and Zinc Alloys - Photoelectric Emission Spectrometry". The three elements Ni, Bi, and Sb were also tested using the spark source atomic emission spectrometry method. The chemical composition segregation of the four ingot test pieces was inspected. Five points were excited on each of the eight test pieces (at the center, edge, 1 / 2 radius, 1 / 4 radius, and 3 / 4 radius of the test piece, respectively). Figure 6 As shown, 5×8 analysis data were obtained.

[0068] The single factor variance analysis method was used to analyze the distribution of each element composition. From the statistical results, it can be seen that the F statistical values ​​of each component of the ingot of pure zinc standard material (5 kinds) are all less than the critical value, as shown in Table 6. This shows that the uniformity of pure zinc standard material (5 kinds) is qualified in the initial inspection.

[0069] Table 6 Summary of initial uniformity inspection results 2. Uniformity test 2.1 Uniformity test method According to the provisions of 5.5 of JJF 1343-2022 "Value Determination and Uniformity and Stability Evaluation of Standard Materials", the sampling method should take into account the defects of the preparation method to ensure the representativeness of the uniformity evaluation. The sampling points should be drawn from the parts where the characteristic values ​​to be determined may differ. The distribution of the sampling points should be representative enough for the overall sample. Five pieces of the finished sample blocks processed from each ingot of the pure zinc standard material are selected, and a total of 20 standard materials are selected. They are numbered in sequence, and the pure zinc standard materials 41XZ3 M and 41XZ5 N with representative element content are selected for calibration on the SPECTROLAB spark source atomic emission spectrometer. After calibration, a uniformity inspection test is carried out. Each sample block is excited three times, and the three excitation points are evenly distributed on the sample surface. Figure 7 As shown, 3×20 data are obtained for each element, and the measurement scheme adopted is as follows: First time: 1–3–5–7–9–11–13–15–17–19–2–4–6–8–10–12–14–16–18–20; Second time: 20–19–18–17–16–15–14–13–12–11–10–9–8–7–6–5–4–3–2–1; The third time: 2–4–6–8–10–12–14–16–18–20–1–3–5–7–9–11–13–15–17–19.

[0070] 2.2 Mathematical statistical model and test results of uniformity The single factor variance method was used to perform statistical processing on the 20 groups of data tested three times. The variance method is a common method used to test uniformity. By comparing the variance between groups and the variance within groups, it is determined whether there is a systematic deviation between the measurement values ​​of each group.

[0071] The statistical model evaluated is: random draw m Each sample was measured repeatedly under the same experimental conditions using a high-precision measurement method. n times, measured m Group precision measurement data: average value ; average value ; ; average value ; Calculate the overall average Calculate the sum of squares of deviations between groups Calculate the within-group sum of squares of deviations Calculating degrees of freedom ; Between-group variance s 1 2 = Q 1 / v 1 Within-group variance s 2 2 = Q 2 / v 2 Make statistics F : Judgment: According to the significance level and degrees of freedom ,from The critical value table is found .Compare and :like , it is considered that there is no significant difference within and between groups and the sample is uniform.

[0072] The uniformity inspection results are shown in Table 7. It can be seen that the F statistical values ​​of the standard substances are all less than the F critical value. Therefore, it can be judged that the pure zinc standard substances (5 types) are uniform and there is no abnormality.

[0073] Table 7 Uniformity test results 3. Stability test Stability is one of the key properties of all reference materials. The value of each property may change over time for a variety of reasons. The extent and rate of change depends on conditions, especially three very important conditions: long-term storage conditions at the reference material producer's facilities, transportation conditions to the user, and storage and use conditions specified by the user.

[0074] The standard material development (production) organization should evaluate the long-term stability and stability of the sample under reasonably expected transportation conditions before distribution. Transportation stability is related to any additional impact caused by sample transportation and is often referred to as "short-term stability". Since the melting point of zinc is 419.53℃ and the boiling point is 907℃, the pure zinc standard material (5 kinds) will not be affected by temperature changes and packaging placement during transportation and severe weather conditions, which will affect the short-term stability. Therefore, the impact of short-term stability can be ignored for this standard material, and the impact of long-term stability can be mainly evaluated.

[0075] 3.1 Long-term stability test method According to the stability monitoring of similar standard substances and the experience of developing such standard substances, this type of standard substances has good stability and there is no trend change in the stability data. The present invention adopts trend analysis method to evaluate the long-term stability of standard substances, and for pure zinc standard substances (5 kinds) stored at room temperature, 2 samples are randomly selected at each time point, each sample is milled into chips, bottled and used, and within 12 months, 6 time points are selected according to the principle of dense time intervals first and sparse time intervals later, which are June 14, 2021, July 16, 2021, September 13, 2021, November 15, 2021, February 14, 2022, and June 23, 2022, and the time intervals are 0 month, 1 month, 3 months, 5 months, 8 months, and 12 months, respectively.

[0076] The long-term stability test method adopts inductively coupled plasma emission spectroscopy. For each characteristic value, two bottles of samples are tested at a specific time point. Three samples are taken from each bottle for testing. The sampling volume of each sample is 1g. Without exceeding the repeatability limit of the method, the average value of the three measurements is taken for statistics.

[0077] According to the provisions of JJF 1343-2022 "Value determination, uniformity and stability evaluation of reference materials", the stability of reference materials is evaluated using the classical model. The basic linear model for stability evaluation can be expressed as the following formula: Y = β 0 +β 1 X Where: β 0—intercept; β1—slope; X -time; Y —Characteristic values ​​of candidate reference materials.

[0078] For a stable standard substance, the ideal expectation is that the intercept of the straight line (within the uncertainty range) is equal to the value of the standard substance; at the same time, the slope of the straight line is β 1 approaches zero.

[0079] Usually, since each time point is extracted p unit samples, repeated measurements, etc., so each X i Will correspond p indivual Y i value; for trend analysis, X i , you can use p Sampling unit Y i average value Regression analysis was performed. The intercept was calculated by using a univariate linear model-linear least squares method. β 0 and slope β 1Estimate of the true value b 0 and b 1, and the corresponding standard deviation and .

[0080] b 0 and b 1The calculation formula is as follows: Where: b 1——linear regression slope; b 0——Linear regression intercept; X - interval time; Y - characteristic quantity values ​​of candidate reference materials; ——The i-th time point Y i ——the observed value at the ith time point; ——the average value of all time points; ——the average value of all observations; n——number of measurements; s – standard deviation of each point on the straight line; s ( b 1)——Standard deviation of the slope; Taking the degrees of freedom as n-2, at a 95% confidence level, the t factor is 2.78. If the result satisfies , then the standard substance is considered to be stable during the observation time.

[0081] 3.2 Long-term stability test results The long-term stability test results, judgment conclusions and uncertainty calculation results of each standard substance are listed in Table 8. The test results show that the statistics of each element meet the requirements. , indicating that the slopes of the trend lines of the stability investigation of the pure zinc standard substances (5 kinds) within 12 months are not significant, that is, the characteristic values ​​of each element have not undergone obvious directional changes, and the values ​​are stable within the storage period of 12 months.

[0082] Table 8 Stability test results 3.3 Stability monitoring of similar reference materials and standard samples According to the method recommended in JJF 1343-2012 "Value determination, uniformity and stability evaluation of reference materials", the stability of pure zinc spectral international reference materials with similar preparation process, similar ingredients and composition is monitored. From the comparison between the monitoring values ​​and the standard values, it can be seen that the standard samples and reference materials have good stability within 10 years.

[0083] 3.4 Determination of the validity period of reference materials Based on the 12-month stability test of the standard substances and the stability monitoring results of similar pure zinc spectral analysis standard substances and standard samples, the validity period of the developed pure zinc spectral analysis standard substances (5 types) is stipulated as follows: The validity period of pure zinc spectral analysis standard substances (5 kinds) is 10 years; The pure zinc spectral analysis standard substances (5 kinds) are monitored for a long time. The research and development unit will regularly monitor the stability of the standard substances and notify customers in time if any changes occur.

[0084] 4. Fixed value analysis 4.1 Preparation of reference material samples Sixteen samples of the five numbered pure zinc standard substances provided in this embodiment are randomly selected from each number and processed into chips, which are fully mixed, bottled, labeled, and stored at room temperature in a cool, dark storage room as fixed value analysis samples.

[0085] 4.2 Selection of standard material valuation method This standard material is determined by the cooperation of multiple laboratories in accordance with the requirements of JJF1006-1994 "Technical Specifications for Primary Standard Materials". In addition to the applicant's unit, domestic units with high testing levels are specially invited to participate in the determination analysis. These laboratories have laboratory accreditation, metrology certification qualifications or participate in the drafting of zinc and zinc alloy chemical analysis methods and have passed ISO9000 quality management system certification. They have advanced instruments and equipment and strong technical force. Before the sample distribution, the capabilities of the other seven laboratories were confirmed and an operating instruction was formulated. The requirements are as follows: (1) The cooperative valuation unit shall have a technical person in charge to organize and specifically guide the valuation work, understand the valuation requirements of reference materials, and the analysts shall be technicians with rich experience in component analysis.

[0086] (2) The instruments and equipment used for fixed value analysis (including balances and measuring instruments) have been verified / calibrated by the national metrology verification institution or a calibration institution accredited by CNAS and are within the validity period.

[0087] (3) The standard substances (including standard solutions) used in the fixed value analysis are all national certified standard substances (numbered GBW) and can be traced back to the International System of Units within the validity period.

[0088] (4) The analytical method selected for the fixed value analysis is a method that has been proven to be accurate and reliable in theory and practice, including methods specified in national standards and industry standards, or analytical methods developed by the applicant's unit. Self-developed analytical methods that have been proven to be accurate and reliable may also be used.

[0089] (5) Two samples of each numbered standard substance shall be issued, each sample shall be measured twice independently, and the results of four independent measurements shall be reported.

[0090] (6) The determination result of each element is expressed as mass fraction (w / %). The number of digits retained for each determination result is 0.0xxx%, 0.00xxx%, 0.000xx%. The numerical rounding shall be carried out in accordance with the provisions of GB / T 8170-2008.

[0091] (7) The valuation report may be submitted in accordance with the original reporting format of the valuation unit, and the report shall at least include the name and number of the analytical method, the name and model of the instrument and equipment, etc.

[0092] (8) All calibration work shall be completed within 2 months after receiving the samples and operating instructions. If the data is out of the group after summary, it needs to be re-inspected.

[0093] 4.3 Traceability of measurement value This standard material adopts the collaborative value determination of multiple laboratories. The value determination unit is a qualified national authority and 8 laboratories with good technical capabilities in the industry. The value determination unit has passed CNAS accreditation or CMA qualification certification or 9001 system certification, has the ability to test standard materials that meet the requirements, and guarantees its traceability.

[0094] The testing equipment and instruments used in the fixed value laboratory have all passed verification or calibration.

[0095] The standard substances used in the test are all nationally certified standard substances.

[0096] The valuation methods include the national standard method and the enterprise standard method. The inventors have confirmed the national standard analysis method and conducted a method study on the enterprise standard method.

[0097] 4.4 Technical review and statistical testing of fixed value analysis data Each collaborative analysis and determination unit measures 2 minimum units, and each unit is measured independently twice, providing 4 measurement data. The data are statistically processed in accordance with the provisions of JJF 1343-2022 "Value Determination and Uniformity and Stability Evaluation of Reference Materials", and finally the standard value of the reference material is determined.

[0098] 4.4.1 Outlier Test 4.4.1.1 Outliers within a group Grubbs test was used to test the suspicious values ​​within the group. The measurement data within each independent value group of each laboratory were arranged in ascending order. 1, x 2,.... x n-1, x n .

[0099] When the statistic , When , there are no abnormal values; or When , there are outliers; or When there are highly abnormal values, they should be eliminated in theory. In the actual statistical process, the research team further judged the outliers within the group using the repeatability limit of the analytical method. When the maximum difference between the fixed value data and the average value within the group is less than the repeatability limit of the fixed value method, the outliers are retained, otherwise the outliers are eliminated.

[0100] After evaluation, all data are retained and used in the next step of calculation.

[0101] 4.4.1.2 Inter-group outlier test Dixon method was used to test whether there was a significant difference between the mean values ​​and to eliminate abnormal values. The measured data were arranged in order from small to large: calculate Value and value. is the critical value, if ,and , then determine is an outlier; if ,and , then determine is an outlier; if and The values ​​are less than If the value is valid, all data will be retained.

[0102] The results of the outlier test are shown in Tables 9 to 13. The test results indicate that there are no outliers in each element of SYD1001, SYD1002, SYD1003, SYD1004, and SYD1005.

[0103] Table 9 Results of the outlier test for SYD1001 between groups Table 10 Results of the outlier test for SYD1002 between groups Table 11 Results of the outlier test for SYD1003 between groups Table 12 Results of the outlier test for SYD1004 between groups Table 13 Results of the outlier test for SYD1005 between groups 4.4.2 Normality test The Shapiro-Wilk method is used to test the normality of the data distribution. The statistic for the Shapiro-Wilk test is: The criterion for this statistic is that when the measured data is accepted as being normally distributed. is a value related to the number of measurements and the confidence probability. When the statistic W > W0.05, the data is approximately normally distributed and is considered normal and retained; when W < W0.01, the normality of the data is poor.

[0104] The results of the normality test are shown in Tables 14 to 18. The test results indicate that the Sb element in SYD1003 is approximately normally distributed, and the data of each element in the remaining SYD1001, SYD1002, SYD1004, and SYD1005 are all normally distributed.

[0105] Table 14 Results of the normality test for SYD1001 Table 15 Results of the normality test for SYD1002 Table 16 Results of the normality test for SYD1003 Table 17 Results of the normality test for SYD1004 Table 18 SYD1005 normality test results 4.4.3 Equal precision test Cochran's method is used to test whether the mean values ​​are of equal precision. First calculate Groups of data The variance of the data, and then calculate the maximum variance and The ratio of the sum of variances: According to the significance level , number of data sets , repeated measurement times , check the Cochran test critical value table and get the critical value .

[0106] like , indicating that the average values ​​of each group of data are of equal precision. , indicating that the maximum variance tested is an outlier. The outlier variance indicates that the accuracy of this group of data is worse than that of other groups of data. When calculating the fixed value results with unequal accuracy, the unequal accuracy weighted processing can be considered. When calculating the fixed value results, the unequal accuracy situation can be used.

[0107] The equal precision test of each fixed value element in this standard material (5 kinds) is shown in Table 19 to Table 23. The test shows that the Fe and Sb elements in SYD1003 and the Cd element in SYD1005 are approximately equal in precision, and the data of each element in the other sample numbers are of equal precision.

[0108] Table 19 SYD1001 equal precision statistical results Table 20 SYD1002 equal precision statistical results Table 21 SYD1003 equal precision statistical results Table 22 SYD1004 equal precision statistical results Table 23 SYD1005 equal precision statistical results 5. Uncertainty assessment The mean of the average values ​​of the characteristic quantity fixed value data of each laboratory is taken as the standard value of the characteristic quantity.

[0109] The uncertainty of the reference material value consists of the following three parts: (1) Uncertainty introduced by the determination process; (2) Uncertainty introduced by the homogeneity of the standard material; (3) Uncertainty introduced by the instability of standard materials 。

[0110] Combined uncertainty of reference material = Expanded uncertainty , k is the expansion factor.

[0111] 5.1 Uncertainty introduced by the determination process This standard material adopts a multi-value determination method and adopts multiple national standard methods, and the data is in the form of 4 groups of data for each laboratory. According to JJF1343-2012 "Value determination and uniformity and stability evaluation of standard materials", the standard deviation of the mean value under this value determination mode is the value determination uncertainty.

[0112] The calculation formula for the uncertainty introduced by the setting process is: Where s is the standard deviation among the laboratories that determine the value; n is the number of collaborative laboratories that determine the value.

[0113] 5.2 Uncertainty introduced by homogeneity of reference materials This type of uncertainty can be statistically evaluated through the uniformity test results. The standard deviation introduced by uniformity is calculated according to the following formula: Where: is the between-group variance, is the within-group variance; is the sum of squares of between-group deviations, ; is the within-group sum of squares, ; is the degree of freedom, , ; is the number of units; is the number of determinations per cell.

[0114] when hour, Equivalent to the uncertainty component caused by the heterogeneity between groups : = ; When the measurement method for uniformity assessment has poor repeatability, The following formula should be used: 5.3 Uncertainty introduced by stability Since the zinc spectral standard material has good stability, the short-term stability effect can be ignored, so only the uncertainty introduced by long-term stability is considered.

[0115] The uncertainty introduced by stability is: Where X is the validity period.

[0116] Based on the above tests, the standard values ​​and uncertainties of the five standard substances provided in this example are finally determined as shown in Tables 24 to 28.

[0117] Table 24 Summary of SYD1001 standard values ​​and uncertainties (%) (95% confidence level, k =2, n=8) Table 25 Summary of SYD1002 standard values ​​and uncertainties (%) (95% confidence level, k =2, n=8) Table 26 Summary of SYD1003 standard values ​​and uncertainties (%) (95% confidence level, k =2, n=8) Table 27 Summary of SYD1004 standard values ​​and uncertainties (%) (95% confidence level, k=2, n=8) Table 28 Summary of SYD1005 standard values ​​and uncertainties (%) (95% confidence level, k=2, n=8) The standard substances (5 kinds) for pure zinc spectral analysis provided in this embodiment have reasonable composition design, advanced preparation technology, good uniformity and stability, and accurate value determination. They are suitable for quantitative analysis of 10 elements, namely Pb, Cd, Fe, Cu, Sn, Al, Ni, Bi, Sb, and Mg, in pure zinc, and can also be used for instrument calibration, measurement method evaluation, and production control of such products.

[0118] The above five kinds of standard substances were entrusted to the testing center of Henan Yuguang Gold and Lead Co., Ltd. and Yifeng Hardware Products Factory in Shiwan Town, Boluo County for testing and trial use. Users all reported that the composition design of the standard substances was reasonable and the data was stable, indicating that the samples were uniform and the values ​​were accurate, which played an important guiding role in the status of instruments and equipment and production quality monitoring.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A standard substance for pure zinc spectral analysis, characterized in that: The elements in the standard substance are as follows: Pb: 0.001~0.003%; Cd: 0.001~0.003%; Fe: 0.0005~0.003%; Cu: 0.0005~0.002%; Sn: 0.0005~0.0015%; Al：0.0005~0.0025%； Ni: 0.0005~0.003%; Bi: 0.0005~0.0025%; Sb: 0.0005~0.0025%; Mg: 0.0001~0.0025%; the balance is Zn.

2. The pure zinc standard substance for spectral analysis according to claim 1, characterized in that: The elements in the standard substance are as follows: Pb: 0.001~0.002%; Cd: 0.001~0.002%; Fe: 0.0005~0.0015%; Cu: 0.001~0.002%; Sn: 0.0008~0.0015%; Al: 0.0005~0.001%; ​​Ni: 0.0005~0.001%; Bi: 0.0005~0.0015%; Sb: 0.0005~0.0015%; Mg: 0.0001~0.0005%; the balance is Zn.

3. The pure zinc standard substance for spectral analysis according to claim 1, characterized in that: The elements in the standard substance are as follows: Pb: 0.001~0.002%; Cd: 0.001~0.002%; Fe: 0.0005~0.001%; ​​Cu: 0.0005~0.0015%; Sn: 0.0005~0.0015%; Al: 0.001~0.002%; Ni: 0.0005~0.001%; Bi: 0.0005~0.0015%; Sb: 0.0005~0.0015%; Mg: 0.0015~0.0025%; the balance is Zn.

4. The pure zinc standard substance for spectral analysis according to claim 1, characterized in that: The elements in the standard substance are as follows: Pb: 0.002~0.003%; Cd: 0.002~0.003%; Fe: 0.002~0.003%; Cu: 0.0008~0.0015%; Sn: 0.0008~0.0015%; Al：0.0015~0.0025%； Ni: 0.002~0.003%; Bi: 0.0015~0.0025%; Sb: 0.0015~0.0025%; Mg: 0.0005~0.001%; ​​the balance is Zn.

5. The pure zinc standard substance for spectral analysis according to claim 1, characterized in that: The elements in the standard substance are as follows: Pb: 0.0015±0.0001%; Cd: 0.0015±0.0001%; Fe: 0.00092±0.00008%; Cu: 0.0012±0.0001%; Sn: 0.0011±0.0001%; Al: 0.00071±0.00009%; Ni: 0.00063±0.00005%; Bi: 0.00096±0.00007%; Sb: 0.0012±0.0001%; ​​Mg: 0.0003±0.0001%; ​​the balance is Zn; or, Pb: 0.0016±0.0001%; Cd: 0.0015±0.0001%; Fe: 0.00081±0.00006%; Cu: 0.0012±0.0001%; Sn: 0.0011±0.0001%; Al：0.0015±0.0002%； Ni: 0.00057±0.00004%; Bi: 0.00096±0.00005%; Sb: 0.0011±0.0001%; ​​Mg: 0.002±0.0002%; the balance is Zn; or, Pb: 0.0026 ± 0.0002%; Cd: 0.0022±0.0001%; Fe: 0.0025±0.0002%; Cu: 0.001±0.0001%; Sn: 0.0012±0.0001%; Al: 0.0021±0.0003%; Ni: 0.0023±0.0002%; Bi: 0.002±0.0002%; Sb: 0.0022±0.0002%; Mg: 0.00074±0.00008%; the balance is Zn.

6. A standard substance for pure zinc spectral analysis, characterized in that: The elements in the standard substance are as follows: Pb: 0.004~0.006%; Cd: 0.0015~0.0025%; Fe: 0.003~0.005%; Cu: 0.002~0.003%; Sn: 0.0005~0.001%; ​​Al: 0.005~0.01%; the balance is Zn; or, Pb: 0.015~0.025%; Cd: 0.008~0.012%; Fe: 0.01~0.02%; Cu: 0.0015~0.0025%; Sn: 0.0005~0.0015%; Al: 0.002~0.004%; the balance is Zn.

7. The pure zinc standard substance for spectral analysis according to claim 6, characterized in that: The elements in the standard substance are as follows: Pb: 0.0048±0.0003%; Cd: 0.002±0.0001%; Fe: 0.0038±0.0002%; Cu: 0.0022±0.0002%; Sn: 0.00069±0.00006%; Al: 0.0086±0.0008%; the balance is Zn; or, Pb: 0.0196±0.0009%; Cd: 0.0093±0.0004%; Fe: 0.0165±0.0008%; Cu: 0.002±0.0002%; Sn: 0.00092±0.00006%; Al: 0.003±0.0003%; the balance is Zn.

8. The method for preparing a pure zinc standard substance for spectral analysis according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. According to the elemental composition of the standard substance, calculate and prepare various raw materials: including 0# zinc and intermediate alloys or pure metals of other metal elements; S2. Mix and melt various raw materials using a medium frequency induction furnace, wherein the melting temperature is 480-500°C; S3, casting the alloy liquid obtained by smelting in step S2 into an ingot, controlling the casting temperature at 460-480°C and the casting speed at 75-100 mm / min; performing a preliminary inspection on the ingot after obtaining the ingot; S4. Processing the ingots that have passed the initial inspection in step S3 into target specifications to obtain standard materials for pure zinc spectral analysis, and performing uniformity inspection, stability investigation, fixed value analysis and uncertainty assessment respectively, and then packaging the finished products.

9. The preparation method according to claim 8, characterized in that: In step S1, copper, iron and nickel are respectively made of copper-zinc alloy, zinc-iron alloy and zinc-nickel alloy as raw materials, and other metal elements are made of pure metals.

10. The preparation method according to claim 8, characterized in that: The order of adding various raw materials in step S2 is: first mix copper-zinc alloy, zinc-iron alloy, zinc-nickel alloy, pure aluminum, pure antimony and 80% of 0# zinc, and after they are completely melted, add the remaining 0# zinc to cool the melt, and then add pure lead, pure cadmium, pure tin, pure bismuth and pure magnesium.

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