Method for simultaneously determining contents of multiple elements in low-carbon silicon-chromium alloy

Abstract

The invention discloses a method for simultaneously determining the contents of multiple elements in a low-carbon silicon-chromium alloy, which comprises the following steps: firstly, selecting 3-5 low-carbon silicon-chromium alloy standard substances with known contents of silicon, manganese and chromium elements to form a concentration gradient, and crushing a sample to be detected and the selected standard substances into particles of less than 80 meshes; dissolving a to-be-detected sample and the selected standard substance in the solution; and then carrying out data acquisition on the emission spectrum light intensity of the standard substance silicon, manganese and chromium elements, drawing a standard working curve of each element according to the corresponding relationship between the element content and the emission spectrum light intensity, substituting the emission spectrum light intensity of the silicon, manganese and chromium elements of the sample to be detected, which is acquired by the instrument, into the standard working curve, and calculating the content of the silicon, manganese and chromium elements of the sample to be detected. The method solves the problem of sample solution preparation when the ICP spectrometer is used for determining the low-carbon silicon-chromium alloy, the sample solution preparation process is simple, and the determination process is not interfered.

Description

Technical Field

[0001] The invention relates to a method for simultaneously determining the contents of multiple elements in a low-carbon silicon-chromium alloy, and belongs to the field of material analysis and testing. Background Art

[0002] Silicon-chromium alloy is an iron alloy mainly composed of silicon, chromium and iron. It is mainly used as an intermediate alloy for producing medium, low and micro carbon iron by electrosilicon thermal method. It is used as a deoxidizer and chromium additive in steelmaking. The traditional chemical composition analysis method is chemical method, in which silicon element is analyzed by weight method, manganese element is analyzed by titration method, and chromium element is analyzed by titration method. The disadvantage is that each element needs to be detected separately, the operation is cumbersome, the analysis process is lengthy, the amount of chemical reagents used is large, the analysis cost is high, and the accuracy is low.

[0003] Inductively coupled plasma (ICP-AES) emission spectrometry is the most commonly used analytical method for elemental analysis of metal materials. It has the advantages of low detection limit, high sensitivity, good stability, small matrix effect, wide linear range of concentration determination, and simultaneous determination of multiple elements, and has been widely used.

[0004] However, the traditional chemical sample pretreatment method requires the use of a variety of chemical reagents such as hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, phosphoric acid, hydrofluoric acid, sodium nitrite, sodium arsenite, sodium peroxide, etc. The addition of a large amount of chemical reagents to the test solution will interfere with the instrument test and affect the accuracy and repeatability of the measurement. Summary of the invention

[0005] The purpose of the present invention is to provide a method for determining the contents of silicon, manganese and chromium in silicon-chromium alloy by ICP-AES method which is fast, accurate and pollution-free to the instrument, so as to overcome the shortcomings of the prior art.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A method for simultaneously determining the contents of multiple elements in a low-carbon silicon-chromium alloy of the present invention comprises the following steps:

[0008] 1) Selection of low-carbon silicon-chromium alloy standard substances: Select 3-5 low-carbon silicon-chromium alloy standard substances with known silicon 35.0%-55.0%, manganese 0.1%-2.0%, and chromium 30.0%-45.0% element contents to form a concentration gradient;

[0009] 2) Preparation method of solid samples: crush the sample to be tested and the selected low-carbon silicon-chromium alloy standard material into particles smaller than 80 mesh for determination;

[0010] 3) Preparation of standard substance solution: weigh 0.1000-0.2000g of low-carbon silicon-chromium alloy standard substance, place them in 50-100ml coverable containers, add 4-7g of sodium hydroxide, heat at 600-700℃ for not less than 30min, dissolve all the substances in the container in an appropriate amount of deionized water after cooling, mix with 10-20ml of 20%-50% hydrochloric acid aqueous solution and 20-30ml of 40%-60% nitric acid aqueous solution, heat at 200-230℃ until the reaction is complete, add 5-15ml of 5%-10% ammonium persulfate aqueous solution, boil until the ammonium persulfate is completely decomposed, cool and transfer to an appropriate volumetric flask, add 10-30ml of 40%-60% nitric acid aqueous solution, dilute quantitatively with deionized water, and mix well;

[0011] 4) Preparation of the sample solution: weigh 0.1000-0.2000g of the sample to be tested, place them in 50-100ml containers with covers, add 4-7g of sodium hydroxide, heat at 600-700℃ for not less than 30min, dissolve all the substances in the container in an appropriate amount of deionized water after cooling, mix with 10-20ml of 20%-50% hydrochloric acid aqueous solution and 20-30ml of 40%-60% nitric acid aqueous solution, heat at 200-230℃ until the reaction is complete, add 5-15ml of 5%-10% ammonium persulfate aqueous solution, boil until the ammonium persulfate is completely decomposed, cool and transfer to an appropriate volumetric flask, add 10-30ml of 40%-60% nitric acid aqueous solution, dilute quantitatively with deionized water, and mix well;

[0012] 5) Determination of the sample to be tested: Data collection is performed on the emission spectrum intensity of silicon, manganese and chromium elements of the low-carbon silicon-chromium alloy standard material, and the standard working curve of each element is drawn based on the corresponding relationship between the element content and the emission spectrum intensity. The emission spectrum intensity of silicon, manganese and chromium elements of the unknown content sample collected by the instrument is brought into the standard working curve to calculate the silicon, manganese and chromium content of the sample to be tested;

[0013] 6) Select certified reference materials to verify the accuracy of the test results of silicon, manganese and chromium content.

[0014] The beneficial effects of the present invention are as follows: a method for simultaneously determining the contents of silicon, manganese and chromium in a silicon-chromium alloy by ICP-AES method is provided, which is fast, accurate and pollution-free to the instrument; the present invention solves the problem of sample solution preparation when the silicon-chromium alloy is determined by an ICP spectrometer, the sample solution preparation process is simple, and no interference is generated in the determination process; the determination method of the present invention can be applied to sample pretreatment technology for determining the element content of silicon-chromium alloy by other element analysis instruments, and has broad application prospects in the field of material analysis. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the embodiments.

[0016] Example

[0017] 1) Select a series of standard substances with silicon content of 36.10%, 42.35%, 48.80%, and 54.45%; manganese content of 0.10%, 0.44%, 1.15%, and 1.95%; chromium content of 30.55%, 34.94%, 40.15%, and 44.65%;

[0018] 2) After the samples to be tested and the standard substances are crushed, particles smaller than 80 mesh are selected;

[0019] 3) Weigh 0.1500±0.0002g of a series of standard substances with different silicon, manganese and phosphorus content and place them in 100ml silver crucibles respectively, then add 5.0g of sodium hydroxide, cover and heat in 650±10℃ environment for 40min, after cooling, all the substances in the container are dissolved in deionized water, mixed with 12ml hydrochloric acid aqueous solution (volume ratio concentration 35%) and 25ml nitric acid aqueous solution (volume ratio concentration 52%), heated in 220±5℃ environment until the reaction is complete, add 10ml ammonium persulfate aqueous solution (mass ratio concentration 6%), boil until the ammonium persulfate is completely decomposed, transfer to a 200ml volumetric flask after cooling, add 20ml nitric acid aqueous solution (volume ratio concentration 45%), quantitatively dilute with deionized water, and mix;

[0020] 4) The preparation process of the sample solution with unknown content is the same as step 3);

[0021] 5) Using an inductively coupled plasma (ICP-AES) emission spectrometer, set the RF generator power to 1.7 kW, the atomization pressure to 27.0 psi, the argon flow rate to 0.8 L / min, the analysis pump speed to 2.50 ml / min, the sample flushing time to 60 s, the integration time to 30 s for short wave and 10 s for long wave; element analysis line (nm) silicon 251.611, manganese 257.610, chromium 283.563; collect data for a series of standard substances, draw standard working curves for each element, and determine the element content of the sample to be tested when the linear correlation coefficient of each curve is greater than 0.999;

[0022] 6) Select standard substances GSB03-1561-2003 and GSB03-1796-2005 to verify the accuracy of the test results of silicon, manganese and chromium content of the samples to be tested. The relative standard deviation RSD (%) is shown in the table below. As can be seen from the table, the RSD determined by this method is less than 2%. Compared with the standard value, the error of the determination result is within the allowable range of the national standard for chemical analysis.

[0023] Precision and accuracy (n=10)

[0024]

Claims

1. A method for simultaneously determining the content of multiple elements in a low-carbon silicon-chromium alloy, characterized in that: The following steps are involved: 1) Selection of low-carbon silicon-chromium alloy standard substances: Select 3-5 low-carbon silicon-chromium alloy standard substances with known silicon 35.0%-55.0%, manganese 0.1%-2.0%, and chromium 30.0%-45.0% element contents to form a concentration gradient; 2) Preparation method of solid samples: crush the sample to be tested and the selected low-carbon silicon-chromium alloy standard material into particles smaller than 80 mesh for determination; 3) Preparation of standard substance solution: weigh 0.1000-0.2000g of low-carbon silicon-chromium alloy standard substance, place them in 50-100ml coverable containers, add 4-7g of sodium hydroxide, heat at 600-700℃ for not less than 30min, dissolve all the substances in the container in an appropriate amount of deionized water after cooling, mix with 10-20ml of 20%-50% hydrochloric acid aqueous solution and 20-30ml of 40%-60% nitric acid aqueous solution, heat at 200-230℃ until the reaction is complete, add 5-15ml of 5%-10% ammonium persulfate aqueous solution, boil until the ammonium persulfate is completely decomposed, cool and transfer to an appropriate volumetric flask, add 10-30ml of 40%-60% nitric acid aqueous solution, dilute quantitatively with deionized water, and mix well; 4) Preparation of the sample solution: weigh 0.1000-0.2000g of the sample to be tested, place them in 50-100ml containers with covers, add 4-7g of sodium hydroxide, heat at 600-700℃ for not less than 30min, dissolve all the substances in the container in an appropriate amount of deionized water after cooling, mix with 10-20ml of 20%-50% hydrochloric acid aqueous solution and 20-30ml of 40%-60% nitric acid aqueous solution, heat at 200-230℃ until the reaction is complete, add 5-15ml of 5%-10% ammonium persulfate aqueous solution, boil until the ammonium persulfate is completely decomposed, cool and transfer to an appropriate volumetric flask, add 10-30ml of 40%-60% nitric acid aqueous solution, dilute quantitatively with deionized water, and mix well; 5) Determination of the sample to be tested: Data collection is performed on the emission spectrum intensity of silicon, manganese and chromium elements of the low-carbon silicon-chromium alloy standard material, and the standard working curve of each element is drawn based on the corresponding relationship between the element content and the emission spectrum intensity. The emission spectrum intensity of silicon, manganese and chromium elements of the unknown content sample collected by the instrument is brought into the standard working curve to calculate the silicon, manganese and chromium content of the sample to be tested; 6) Select certified reference materials to verify the accuracy of the test results of silicon, manganese and chromium content.

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