Chemical analysis method for nitratine ore components and application of chemical analysis method

Abstract

The invention relates to the technical field of rock ore testing, in particular to a chemical analysis method for nitratine ore components and application of the chemical analysis method. The method comprises the following steps: preparing a test solution by oscillating and filtering at room temperature; determining the content of nitrate radicals; determining the content of sodium ions; and calculating the content of sodium nitrate: calculating the content of sodium nitrate according to ion coordination. The method solves the problems that in the prior art, a nitratine ore chemical analysis method is tedious in operation, and standardized detection cannot be achieved, can provide a feasible method with a unified standard for nitratine ore detection, and can serve geological prospecting.

Description

Technical Field

[0001] The invention relates to the technical field of rock and mineral testing, and in particular to a chemical analysis method for components of sodium nitre ore. Background Art

[0002] Sodium nitrate ore is a mineral resource rich in sodium nitrate (NaNO3). Sodium nitrate resources are abundant in the Tuha Basin. Sodium nitrate ore can be processed to produce natural high-quality sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate products are in short supply in my country and the world. Their added value and functions are better than potassium sulfate and potassium oxide. They are scarce high-quality green potash fertilizers. In addition, sodium nitrate ore is also widely used in construction, medicine, metallurgy, military industry and other fields, and plays a vital role in social and economic development.

[0003] The Ministry of Natural Resources has formulated the "Mineral Geological Exploration Specifications for Salts Part 2: Modern Salt Lakes" DZ / T0212.2-2020, which sets unified requirements for salt lake minerals from topographic surveys, prospecting projects, to the collection, processing and analysis of chemical analysis samples. The mirabilite, rock salt mines, brine mines, etc. mentioned in the standard currently have geological testing methods to follow, but there is no unified and clear testing method for sodium nitrate mines in the standard, which makes the data measured by testers uneven and cannot serve geological prospecting well.

[0004] A search of existing reports shows that the nitrate content in sodium nitre is determined by the ammonium ferrous sulfate redox titration method. This method uses hydrochloric acid to decompose the sample, and the ammonium ferrous sulfate then reduces the nitrate in the test solution to nitrogen oxides. The remaining divalent iron is titrated with a potassium dichromate standard solution, and the amount of ammonium ferrous sulfate consumed is converted into the nitrate content. This method is cumbersome to operate, and the ammonium ferrous sulfate is unstable and needs to be labeled immediately before use, which is not conducive to testing a large number of samples. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a chemical analysis method for the components of sodium nitre ore, which solves the problem that the chemical analysis method of sodium nitre ore in the prior art is cumbersome to operate and cannot be standardized for detection. It can provide a unified standard and feasible method for sodium nitre ore detection and can also serve geological prospecting.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, a chemical analysis method for sodium nitre ore components is provided, the chemical analysis method comprising the following steps:

[0008] Preparation of test solution: Weigh a sodium nitrate ore sample into a container, add deionized water and shake at room temperature, and immediately filter with a 0.1μm-0.3μm filter membrane to obtain the filtrate;

[0009] Determination of nitrate content: prepare nitrate solutions of different concentrations, add phosphoric acid solution and aminosulfonic acid ammonia solution into a colorimetric tube; use distilled water as a reference, measure absorbance values ​​at wavelengths of 200nm-230nm and 265nm-280nm respectively; use nitrate mass as the horizontal coordinate and absorbance as the vertical coordinate to draw a nitrate standard curve; take the filtrate obtained by filtering through the filter membrane into a colorimetric tube, dilute it to the scale line with distilled water, add phosphoric acid solution and aminosulfonic acid ammonia solution into the colorimetric tube, use distilled water as a reference, and measure absorbance values ​​at wavelengths of 200nm-230nm and 265nm-280nm respectively; calculate the concentration of nitrate in the sodium nitre ore sample;

[0010] Determination of sodium ion content: prepare sodium ion standard solutions of different concentrations and use inductively coupled plasma emission spectrometer to establish a calibration curve; the linear correlation coefficient of the calibration curve is not less than 0.999; take the filtrate obtained by filtering through the filter membrane into a volumetric flask, add hydrochloric acid, dilute to the mark with distilled water, and determine the sodium ion content on the inductively coupled plasma emission spectrometer;

[0011] Calculation of sodium nitrate content: The sodium nitrate content is calculated based on ion coordination.

[0012] In the present invention, the concentration of the phosphoric acid solution is 0.01 mol / L-2 mol / L, and the concentration of the aminosulfonic acid ammonia solution is 0.05 g / L-2 g / L.

[0013] Specifically, the analysis method of the present invention comprises the following steps:

[0014] S1. Test solution preparation:

[0015] Weigh m s 1. Put 250 mL of deionized water into a 500 mL conical flask, and shake it on an oscillator at room temperature for 15 min. After taking it out, filter it with a 0.2 μm filter membrane immediately. The filtrate is the sodium nitre test solution. The total volume of the sodium nitre test solution is V. s mL, the sodium ion concentration in the sodium nitre test solution is ρμg / mL;

[0016] S2. Determination of nitrate content:

[0017] S2.1. Drawing of nitrate calibration curve:

[0018] Take 8 50mL colorimetric tubes, add 0mL, 0.25mL, 0.5mL, 1.0mL, 2.0mL, 4.0mL, 6.0mL, 7.5mL nitrate standard solution respectively, dilute to the mark with distilled water, add 1.0mL phosphoric acid solution and 1.0mL aminosulfonic acid ammonia solution into the colorimetric tubes; the nitrate content is 0μg, 25μg, 50μg, 100μg, 200μg, 400μg, 600μg, 750μg respectively, take distilled water as reference, measure the absorbance value at 220nm and 275nm wavelength respectively; draw the nitrate standard curve with nitrate mass as the abscissa and absorbance as the ordinate;

[0019] S2.2. Test of the first test solution:

[0020] Take V0 mL of sodium nitre test solution into a 50 mL colorimetric tube, dilute it to the mark with distilled water, add 1.0 mL of phosphoric acid solution and 1.0 mL of aminosulfonic acid ammonia solution into the colorimetric tube, use distilled water as a reference, and measure the absorbance at 220 nm and 275 nm respectively;

[0021] S2.3. Calculation of nitrate content:

[0022] The calculation formula of nitrate content is:

[0023] Where: W is the nitrate content in sodium nitre (%); m0 is the nitrate concentration corresponding to the nitrate calibration curve; V s is the total volume of sodium nitre test solution (mL); V0 is the volume of sodium nitre test solution taken in step S2.2 (mL); m s is the mass of sodium nitre (g);

[0024] S3. Determination of sodium ion content:

[0025] S3.1. Drawing of sodium ion calibration curve:

[0026] A calibration curve is established using more than 4 sodium ion concentration standard calibration solutions; the linear correlation coefficient of the calibration curve is not less than 0.999;

[0027] S3.2. Test of the second test solution:

[0028] Take V0 mL of sodium nitre test solution in a 100 mL volumetric flask, add 4 mL of hydrochloric acid, dilute to V1 mL with distilled water, and determine the sodium ion content by inductively coupled plasma emission spectrometry;

[0029] S3.3. Calculation of sodium ion content:

[0030] The calculation formula for sodium ion content is:

[0031] Where: W is the sodium ion content in sodium nitre; ρ is the sodium ion concentration in the sodium nitre test solution (μg / mL); ρ0 is the sodium ion content (μg / mL) measured by inductively coupled plasma emission spectrometry after taking V0mL of deionized water in a 100mL volumetric flask, adding 4mL of hydrochloric acid, and diluting the volume to V1mL with distilled water; V1 is the volume of the sodium nitre test solution after the volume is taken (mL); V s is the total volume of the sodium nitre test solution prepared in S1 (mL); V0 is the volume of the sodium nitre test solution taken in step S3.2 (mL); m s is the mass of sodium nitre (g);

[0032] The sodium ion content is measured by inductively coupled plasma emission spectrometry; the sodium nitre test solution of the present invention is acidified with hydrochloric acid, introduced into the matrix tube of the inductively coupled plasma spectrometer by carrier gas through an atomizer, and excited to produce a characteristic spectrum line of the measured element after evaporation, dissociation, atomization and ionization processes, and the signal intensity of the spectrum line is proportional to the concentration of the object to be measured, and the element content in the sample is calculated by measuring the signal intensity of the characteristic spectrum line of the element; the instrument used is inductively coupled plasma emission spectrometry. The reagents used are hydrochloric acid (1+1) and sodium ion standard stock solution (1 mg / L).

[0033] Calculation of sodium nitrate content:

[0034] The content of sodium nitrate was calculated based on ion coordination.

[0035] Preferably, in the test method for nitrate content of the present invention, the absorption of nitrate ions at a wavelength of 205 nm is used to quantitatively determine nitrate nitrogen; another control measurement is made at a wavelength of 270 nm to correct nitrate nitrogen; the instrument used is an ultraviolet spectrophotometer. The reagents used are phosphoric acid (1 mol / L), aminosulfonic acid ammonia (50 g / L), and nitrate standard solution (100 μg / mL).

[0036] Further preferably, the filtrate obtained by filtering with a 0.1 μm-0.3 μm filter membrane is then added with a clarified calcium hydroxide solution, the pH is adjusted to 8-10, and after adjustment, the pH is allowed to stand and then filtered with a 0.1 μm-0.3 μm filter membrane to obtain a filtrate for use.

[0037] In a second aspect, the invention provides an application of the method of the invention in the detection of components of sodium nitre ore, especially in the determination of sodium nitrate content in sodium nitre ore, or in the determination of nitrate content and / or sodium ion content in sodium nitre ore.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] 1) Compared with the traditional method, the present invention designs a suitable ore dissolution method according to the physical and chemical properties of sodium nitre ore to detect nitrate and sodium ions, which not only avoids the influence of other complex mixtures in other ores on the detection of target ions, but also avoids the trouble of appropriately adjusting the measurement method according to the different ore origins, and provides a feasible solution for standardizing the measurement method.

[0040] 2) GB / T 5750.5-2006 has thymol spectrophotometry and ultraviolet spectrophotometry for the colorimetric method of nitrate. In the test process of thymol spectrophotometry, chloride ions have negative interference on the test results, which needs to be eliminated by silver sulfate. However, sodium nitrate ore is accompanied by chlorine-containing halite, so this method increases the experimental steps, and the use of silver sulfate not only increases the detection cost, but also brings a burden to the environment. Although ultraviolet spectrophotometry is not interfered by chloride ions, it is easily interfered by organic matter on the surface of sodium nitrate ore or mixed therein, and hydrochloric acid, which is easy to make drugs, is used in the colorimetric process. Hydrochloric acid is highly volatile and easily causes damage to the respiratory tract and skin, and the purchase procedures are cumbersome and need to be approved by the public security department. The present invention uses phosphoric acid with soft acidity and non-volatile to replace hydrochloric acid, which is easy to make drugs, and has achieved good experimental results.

[0041] 3) The chemical analysis method of sodium nitre ore components of the present invention can be used for raw ore detection in various geological team laboratories, and can also be used for mineral processing units to detect the purity of sodium nitre. The method has low requirements on the detection environment, detection reagents, and detection conditions, and can be adapted to the detection of sodium nitre of different purities. It has universal applicability, can guide geological prospecting, and provide basic geological sample data for prospecting.

[0042] 4) There are many impurities in the ore. Nitrite, chloride ion, sulfate ion, etc. all have absorption peaks near 200nm. A small amount of impurity ions will also be introduced into the deionized water and various reagents used for detection. The organic matter contained in the ore will also appear absorption peaks in the ultraviolet spectrophotometer. How to detect when the impurities have the least impact requires consideration of many complex factors. It is not the best to choose when the nitrate absorption peak is the largest. The 205nm selected by the present invention to measure nitrate and 270nm as a reference are the best. Since there will be negative absorption effects and positive absorption effects in the impurities in the ore and the impurities in the blank sample, the measurement accuracy brought about by the changes in the two measurement parameters is not linear. The present invention has found through experiments that the optimal parameters cannot be obtained through single factor experiments and orthogonal experiments. The wavelength selected by the present invention has the smallest error in determining the standard test solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is the linear correlation diagram of nitrate colorimetry after using phosphoric acid instead of hydrochloric acid. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only 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.

[0045] Example 1 Determination of nitrate content

[0046] Experimental subjects: Eight different sodium nitrate ore samples were dissolved at room temperature and slightly boiling conditions, and the nitrate content was tested.

[0047] Experimental methods:

[0048] S1. Test solution preparation:

[0049] Weigh m s 1. Put 250 mL of deionized water into a 500 mL conical flask, and shake it on an oscillator at room temperature for 15 min. After taking it out, filter it with a 0.2 μm filter membrane immediately. The filtrate is the sodium nitre test solution. The total volume of the sodium nitre test solution is V. s mL, the sodium ion concentration in the sodium nitre test solution is ρμg / mL;

[0050] S2. Determination of nitrate content:

[0051] S2.1. Drawing of nitrate calibration curve:

[0052] Take 8 50mL colorimetric tubes, add 0mL, 0.25mL, 0.5mL, 1.0mL, 2.0mL, 4.0mL, 6.0mL, 7.5mL nitrate standard solution respectively, dilute to the mark with distilled water, add 1.0mL phosphoric acid solution and 1.0mL aminosulfonic acid ammonia solution into the colorimetric tubes; the nitrate content is 0μg, 25μg, 50μg, 100μg, 200μg, 400μg, 600μg, 750μg respectively, take distilled water as reference, measure the absorbance value at 220nm and 275nm wavelength respectively; draw the nitrate standard curve with nitrate mass as the abscissa and absorbance as the ordinate;

[0053] S2.2. Test of the first test solution:

[0054] Take V0 mL of sodium nitre test solution into a 50 mL colorimetric tube, dilute it to the mark with distilled water, add 1.0 mL of phosphoric acid solution and 1.0 mL of aminosulfonic acid ammonia solution into the colorimetric tube, use distilled water as a reference, and measure the absorbance at 220 nm and 275 nm respectively;

[0055] S2.3. Calculation of nitrate content:

[0056] The calculation formula of nitrate content is:

[0057] Where: W is the nitrate content in sodium saltpeter; m0 is the nitrate concentration corresponding to the nitrate calibration curve; V s is the total volume of sodium nitre test solution; V0 is the volume of sodium nitre test solution taken in step S2.2; m s For the mass of sodium nitrate.

[0058] Experimental results: The results are shown in Table 1 below.

[0059] Table 1 Nitrate content measured at different leaching temperatures

[0060]

[0061] As shown in Table 1, the sodium nitrate ore was dissolved at room temperature and under slightly boiling conditions, and the nitrate ion was detected by ultraviolet spectrophotometry. The nitrate ion leaching efficiency under room temperature (23°C) and slightly boiling (95°C) conditions was not much different, and the nitrate ion detection results were not much different. This is different from the general perception. Sodium nitrate is easily soluble in water, and its solubility is 70.7g / 100g at 0°C, 88g / 100g water at 20°C, 96g / 100g water at 30°C, 180g / 100g water at 100°C, 213g / 100g water at 120°C, and 383g / 100g water at 180°C. According to the solubility temperature, the higher the solubility, the better the solubility, and the more accurate the measurement should be. However, after a large number of experiments, it has been proved that when the oscillation of the present invention and the filtration of the filter membrane below 0.1μm-0.3μm exist at the same time, increasing the temperature no longer affects the detection accuracy of the sodium nitre ore components, so that the present invention can adopt room temperature for dissolution and leaching while maintaining a high accuracy. The specifications of the filtration membrane have a great influence on the detection, and both smaller and larger sizes will reduce the detection accuracy.

[0062] Example 2 Ultraviolet spectrophotometric measurement of nitrate in sodium nitre ore

[0063] Existing technical solution: The ultraviolet spectrophotometry method in the colorimetric method for nitrate in GB / T 5750.5-2006 utilizes the property that nitrate has ultraviolet absorption at a wavelength of 220nm and has no absorption at a wavelength of 275nm for determination. The absorption value of organic matter measured at a wavelength of 275nm is corrected in the determination result. This method uses hydrochloric acid in the colorimetric process.

[0064] The technical solution of the present invention is to replace the hydrochloric acid in the prior art solution with phosphoric acid, and quantitatively determine the nitrate nitrogen by using the absorption of nitrate ions at a wavelength of 205nm; another control measurement is made at a wavelength of 270nm to correct the nitrate nitrogen. The technical solution of the present invention and the prior art solution measure the same sodium nitre ore sample.

[0065] Experimental conclusion: The present invention uses mildly acidic and non-volatile phosphoric acid to replace the hydrochloric acid in the prior art solution, which is easy to make drugs. It can achieve better experimental results. The linear correlation coefficient of the standard curve can reach more than 0.999, and the test stability is good. The correlation is shown in Figure 1 , the spike recovery rate is 95% to 103%. In addition, the absorption wavelength adopted by the present invention eliminates the interference of other chloride ions, sulfate ions, and nitrite ions around 200nm, and can also eliminate the interference of various organic substances mixed in the ore. Although the nitrate ion is not the highest absorption intensity, the detection effect is the best, which may be because the detection absorption peak and the control absorption peak selected by the present application are the best match.

[0066] Example 3 Sodium ion and nitrate ion test of sodium nitre ore

[0067] Test objects: 6 pieces of sodium nitrate mines from a certain place in Xinjiang.

[0068] Test method:

[0069] This embodiment provides a chemical analysis method for the components of sodium nitre ore, and the chemical analysis method comprises the following steps:

[0070] S1. Test solution preparation:

[0071] Weigh m s g sodium nitre sample in a 500 mL conical flask, accurately add 250 mL of deionized water, and oscillate on an oscillator at room temperature (23°C) for 15 min; immediately filter with a 0.2 μm filter membrane after taking out, the filtrate is the sodium nitre test solution, and the total volume of the sodium nitre test solution is V s mL, the sodium ion concentration in the sodium nitre test solution is ρμg / mL;

[0072] S2. Determination of nitrate content:

[0073] S2.1. Drawing of nitrate calibration curve:

[0074] Take 8 50mL colorimetric tubes, add 0mL, 0.25mL, 0.5mL, 1.0mL, 2.0mL, 4.0mL, 6.0mL, 7.5mL nitrate standard solution (100μg / mL) respectively, dilute to the mark with distilled water, add 1.0mL phosphoric acid solution (1mol / L) and 1.0mL aminosulfonic acid ammonia solution (50g / L) into the colorimetric tubes; the nitrate content is 0μg, 25μg, 50μg, 100μg, 200μg, 400μg, 600μg, 750μg respectively, take distilled water as reference, measure the absorbance value at 205nm and 270nm wavelength respectively; draw the nitrate standard curve with nitrate mass as the abscissa and absorbance as the ordinate;

[0075] S2.2. Test of the first test solution:

[0076] Take V0 mL of sodium nitre test solution (the volume can be adjusted according to the nitrate content) in a 50 mL colorimetric tube, dilute it to the mark with distilled water, add 1.0 mL of phosphoric acid solution (1 mol / L) and 1.0 mL of aminosulfonic acid ammonia solution (50 g / L) in the colorimetric tube, use distilled water as a reference, and measure the absorbance at 205 nm and 270 nm respectively;

[0077] Nitrate nitrogen is quantitatively determined using the absorption of nitrate and ions at a wavelength of 220nm; dissolved organic matter also absorbs at 205nm, while nitrate and ions do not absorb at 270nm; therefore, another measurement is made at 270nm to correct for nitrate nitrogen. 校 =A 205 -2A 270 ; Where: A 205 The absorbance value is measured at a wavelength of 205 nm; A 270 The absorbance value was measured at a wavelength of 270 nm.

[0078] S2.3. Calculation of nitrate content:

[0079] The calculation formula of nitrate content is:

[0080] Where: W is the nitrate content in sodium saltpeter; m0 is the nitrate concentration corresponding to the nitrate calibration curve; V s is the total volume of sodium nitre test solution; V0 is the volume of sodium nitre test solution taken in step S2.2; m s is the mass of sodium nitrate;

[0081] S3. Determination of sodium ion content:

[0082] S3.1. Drawing of sodium ion calibration curve:

[0083] The calibration curve is established by measuring the four sodium ion concentration standard calibration solutions by inductively coupled plasma emission spectrometry; the linear correlation coefficient of the calibration curve is not less than 0.999;

[0084] S3.2. Test of the second test solution:

[0085] Take V0 mL of sodium nitre test solution in a 100 mL volumetric flask, add 4 mL of hydrochloric acid (concentrated hydrochloric acid and deionized water are prepared in a volume ratio of 1:1), dilute to V1 mL with distilled water, and determine the sodium ion content by inductively coupled plasma emission spectrometry;

[0086] The sodium nitre solution is acidified with hydrochloric acid, introduced into the matrix tube of the inductively coupled plasma spectrometer through a nebulizer and carrier gas. After evaporation, dissociation, atomization and ionization, the characteristic spectral line of the element to be measured is excited. The signal intensity of the spectral line is proportional to the concentration of the analyte. The element content in the sample is calculated by measuring the signal intensity of the characteristic spectral line of the element.

[0087] S3.3. Calculation of sodium ion content:

[0088] The calculation formula for sodium ion content is:

[0089] Where: W is the sodium ion content in sodium nitre; ρ is the sodium ion concentration in the sodium nitre test solution (μg / mL); ρ0 is to take V0mL of deionized water in a 100mL volumetric flask, add 4mL of hydrochloric acid, and dilute to V1mL with distilled water, and measure the sodium ion content (μg / mL) on the inductively coupled plasma emission spectrometer; V1 is the volume of the sodium nitre test solution after the volume is taken; V s is the total volume of sodium nitre test solution; V0 is the volume of sodium nitre test solution taken in step S3.2; m s For the mass of sodium nitrate.

[0090] Test results: The results are shown in Table 2 below.

[0091] Table 2 Sodium ion and nitrate ion test results of sodium saltpeter ore

[0092]

[0093]

[0094] As can be seen from Table 2, the scheme of the present invention can be used to measure the sodium ion content and nitrate ion content in a sodium nitre mine in Xinjiang, and has good accuracy and adaptability.

[0095] Embodiment 4:

[0096] The difference from Example 3 is that when preparing the S1 test solution, the filtrate obtained by filtering with a 0.1 μm filter membrane is added with a clarified calcium hydroxide solution, the pH is adjusted to 8-10, and after adjustment, it is allowed to stand and then filtered with a 0.3 μm filter membrane to obtain the final filtrate for use. The filtrate is the sodium nitre test solution, and the total volume of the sodium nitre test solution is V s mL, the sodium ion concentration in the sodium nitre test solution is ρμg / mL.

[0097] After 10 consecutive measurements of the same ore sample analysis comparison, the floating deviation of the results obtained from different measurements was recorded. The measurement accuracy of Example 3 was compared with that of Example 4 as follows:

[0098]

[0099] It can be seen that after multiple groups of experiments and comparisons of samples from the same mine, the natural error caused by the unevenness of the sodium nitre ore itself can be offset. The addition of calcium hydroxide solution in this embodiment greatly improves the measurement accuracy for pH adjustment and secondary filtration, which significantly reduces the measurement error.

[0100] The embodiments described above are only some embodiments of the present invention, not all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but only represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the concept of the present invention belong to the scope of protection of the present invention.

Claims

1. A chemical analysis method for sodium nitre ore components, characterized in that: The method comprises the following steps: Preparation of test solution: Weigh a sodium nitrate ore sample into a container, add deionized water and shake at room temperature, and immediately filter with a 0.1μm-0.3μm filter membrane to obtain the filtrate; Determination of nitrate content: prepare nitrate solutions of different concentrations, add phosphoric acid solution and aminosulfonic acid ammonia solution into a colorimetric tube; use distilled water as a reference, measure absorbance values ​​at wavelengths of 200nm-230nm and 265nm-280nm respectively; use nitrate mass as the horizontal coordinate and absorbance as the vertical coordinate to draw a nitrate standard curve; take the filtrate obtained by filtering through the filter membrane into a colorimetric tube, dilute it to the scale line with distilled water, add phosphoric acid solution and aminosulfonic acid ammonia solution into the colorimetric tube, use distilled water as a reference, and measure absorbance values ​​at wavelengths of 200nm-230nm and 265nm-280nm respectively; calculate the concentration of nitrate in the sodium nitre ore sample; Determination of sodium ion content: prepare sodium ion standard solutions of different concentrations and use inductively coupled plasma emission spectrometer to establish a calibration curve; the linear correlation coefficient of the calibration curve is not less than 0.999; take the filtrate obtained by filtering through the filter membrane into a volumetric flask, add hydrochloric acid, dilute to the mark with distilled water, and determine the sodium ion content on the inductively coupled plasma emission spectrometer; Calculation of sodium nitrate content: The sodium nitrate content is calculated based on ion coordination.

2. The chemical analysis method of sodium nitre ore components according to claim 1, characterized in that: The concentration of the phosphoric acid solution is 0.01 mol / L-2 mol / L, and the concentration of the aminosulfonic acid ammonia solution is 0.05 g / L-2 g / L.

3. The chemical analysis method of sodium nitre ore components according to claim 1, characterized in that: The steps of the method are as follows: S1. Test solution preparation: Weigh m s g sodium nitre sample in a container, add deionized water, and oscillate on an oscillator at room temperature; immediately filter with a 0.2 μm filter membrane after oscillation, and the filtrate is the total sodium nitre test solution; S2. Determination of nitrate content: S2.

1. Drawing of nitrate calibration curve: Take several colorimetric tubes and add 0mL-10mL of nitrate standard solution respectively. The volume of standard solution added to all colorimetric tubes is different and regularly distributed. After adding, dilute with distilled water to the mark, and add phosphoric acid solution and aminosulfonic acid ammonia solution into the colorimetric tubes; Using distilled water as reference, measure the absorbance at 220nm and 275nm wavelengths respectively; draw a nitrate standard curve with the mass of nitrate as the horizontal axis and the absorbance as the vertical axis; S2.

2. Test of the first test solution: Take V0 mL of sodium nitre test solution into a colorimetric tube, dilute it to the mark with distilled water, add phosphoric acid solution and aminosulfonic acid ammonia solution into the colorimetric tube, use distilled water as a reference, and measure the absorbance at 220nm and 275nm respectively; S2.

3. Calculation of nitrate content: The calculation formula of nitrate content is: Wherein: W is the nitrate content in sodium nitre; m0 is the nitrate concentration corresponding to the nitrate calibration curve; Vs is the total volume of the sodium nitre test solution described in S1; V0 is the volume of the sodium nitre test solution taken in step S2.2; m s is the mass of sodium nitrate sample used in S1; S3. Determination of sodium ion content: S3.

1. Drawing of sodium ion calibration curve: The calibration curve is established by testing more than 4 sodium ion concentration standard calibration solutions; the linear correlation coefficient of the calibration curve is not less than 0.999; S3.

2. Test of the second test solution: Take V0 mL of sodium nitre test solution into a volumetric flask, add hydrochloric acid, make up to V1 mL with distilled water, and determine the sodium ion content on an inductively coupled plasma emission spectrometer; S3.

3. Calculation of sodium ion content: The calculation formula for sodium ion content is: Wherein: W is the sodium ion content in sodium nitre; ρ is the sodium ion concentration in the sodium nitre test solution; ρ0 is the sodium ion concentration in the blank solution; V1 is the fixed volume of the sodium nitre test solution after the aliquot; Vs is the total volume of the sodium nitre test solution described in S1; V0 is the aliquot volume of the sodium nitre test solution in step S3.2; m s is the mass of sodium nitrate sample used in S1. S4. Calculation of sodium nitrate content: The content of sodium nitrate was calculated based on ion coordination.

4. The chemical analysis method according to claim 3, characterized in that: The concentration of the phosphoric acid solution in step S2.1 is 1 mol / L, and the concentration of the aminosulfonic acid ammonia solution in step S2.1 is 50 g / L.

5. The chemical analysis method according to claim 3, characterized in that: The concentration of the phosphoric acid solution in step S2.2 is 1 mol / L, and the concentration of the aminosulfonic acid ammonia solution in step S2.2 is 50 g / L.

6. The chemical analysis method according to claim 3, characterized in that: The hydrochloric acid in step S3.2 is a mixed solution of concentrated hydrochloric acid and water in a volume ratio of 1:

1.

7. The chemical analysis method according to claim 1, characterized in that: In the test method for nitrate content, the absorption of nitrate ions at a wavelength of 205 nm is used to quantitatively determine nitrate nitrogen; another control measurement is performed at a wavelength of 270 nm to correct for nitrate nitrogen.

8. The chemical analysis method according to claim 1, characterized in that: The filtrate obtained by filtering with a 0.1 μm-0.3 μm filter membrane is then added with a clarified calcium hydroxide solution, the pH is adjusted to 8-10, and after adjustment, the pH is allowed to stand and then filtered with a 0.1 μm-0.3 μm filter membrane to obtain a filtrate for use.

9. Application of the method described in claim 1 in determining the sodium nitrate content in a sodium nitre ore.

10. Application of the method according to claim 1 in determining the nitrate content and / or sodium ion content in sodium nitre ore.

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