Method for determining total iron content of vanadium titano-magnetite by using invalid Na2O2

Abstract

The invention provides an application of anhydrous Na2CO3 in determination of the total iron content of vanadium titano-magnetite by using invalid Na2O2. The determination method comprises an alkali fusion method. The melting temperature of the alkali fusion method is 820-860 DEG C. The invention further provides a method for measuring the total iron content of the vanadium titano-magnetite by adopting the invalid Na2O2, the dissolution rate of a sample is increased to 99% or above by specially setting the melting temperature at 820-860 DEG C and combining corresponding melting time, the problem that sodium peroxide is difficult to effectively utilize in an invalid state is solved, and the total iron content of the vanadium titano-magnetite is measured by adopting an innovative technical means. The deep reutilization of the waste in the field of fine analytical chemistry is realized. The breakthrough not only broadens the channel of waste utilization, but also significantly improves the comprehensive utilization rate of resources, and brings huge economic value and social benefit to related industries.

Description

Technical Field

[0001] The present invention relates to the technical field of determination of the total iron content of vanadium-titanium magnetite, and relates to the application of anhydrous Na2CO3 in determining the total iron content of vanadium-titanium magnetite using failed Na2O2, and a method for determining the total iron content of vanadium-titanium magnetite using failed Na2O2, and in particular to a method for determining the total iron content of vanadium-titanium magnetite using failed Na2O2. Background Art

[0002] In the determination of the total iron content of vanadium-titanium magnetite, an alkali fusion method is used to determine the TFe melt sample using a mixed flux (Na2O2 + anhydrous Na2CO3). When sodium peroxide is left in the air for a long time, a portion of it will absorb water in the air to form sodium hydroxide, which in turn reacts with carbon dioxide in the air to form sodium carbonate. A portion of the sodium peroxide also reacts with carbon dioxide in the air to form sodium carbonate. The final product is sodium carbonate, which will result in a melting rate of only about 55% for ore samples (TFe: 30%) or more, seriously affecting work progress and greatly affecting the accuracy of inspection results. In actual production, discarding these failed Na2O2 will cause corresponding waste of resources and increase production costs.

[0003] Therefore, how to solve the above problems existing in the existing vanadium-titanium magnetite-total iron content determination and realize the effective utilization of failed Na2O2 in the chemical analysis process has become one of the urgent problems to be solved by many front-line researchers in this field. Summary of the Invention

[0004] The purpose of the present invention is to provide the use of anhydrous Na2CO3 in determining the total iron content of vanadium titanomagnetite using spent Na2O2, in particular, a method for determining the total iron content of vanadium titanomagnetite using spent Na2O2 (Na2O2+NaOH+Na2CO3). The method developed by the present invention for determining the total iron content of vanadium titanomagnetite using spent Na2O2 enables the effective utilization of spent Na2O2 in chemical analysis processes and solves the problem of deep reuse of this substance in the field of fine analytical chemistry. This innovative breakthrough not only greatly broadens the avenues for waste utilization, but also significantly improves the comprehensive utilization rate of resources, bringing extremely considerable economic value and social benefits to related industries.

[0005] The present invention provides the use of anhydrous Na2CO3 in determining the total iron content of vanadium-titanium magnetite using spent Na2O2;

[0006] The determination method includes an alkali fusion method;

[0007] The melting temperature of the alkali fusion method is 820-860°C.

[0008] Preferably, the failed Na2O2 is specifically a failed Na2O2, in which the mass content of Na2O2 is 60% to 80%;

[0009] The TFe grade of the vanadium-titanium magnetite is 30% to 60%.

[0010] Preferably, the application is specifically the application of anhydrous Na2CO3 and spent Na2O2 as a mixed flux;

[0011] The mass ratio of the anhydrous Na2CO3 to the spent Na2O2 is 1:4;

[0012] The mass ratio of the vanadium-titanium magnetite sample to the mixed flux is (0.1999-0.2001):(5-6).

[0013] The present invention provides a method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2, comprising the following steps:

[0014] 1) Mixing the ore sample and the mixed flux, placing them in a heating device, melting them at high temperature, and cooling them to obtain a frit;

[0015] The mixed flux includes spent Na2O2 and anhydrous Na2CO3;

[0016] 2) placing the frit obtained in the above step in water for reaction, then heating it, and then adding concentrated hydrochloric acid for leaching to obtain a leachate;

[0017] 3) The leaching solution obtained in the above step is subjected to a tin dichloride and titanium trichloride combined reduction-potassium dichromate titration method to calculate the TFe content in the ore sample.

[0018] Preferably, the ore sample comprises vanadium-titanium iron concentrate;

[0019] The TFe grade of the ore sample is 30% to 60%;

[0020] The mass ratio of the ore sample to the mixed flux is (0.1999-0.2001):(5-6).

[0021] Preferably, the failed Na2O2 is specifically a failed Na2O2, in which the mass content of Na2O2 is 60% to 80%;

[0022] The mass ratio of the anhydrous Na2CO3 to the spent Na2O2 is 1:4.

[0023] Preferably, the high temperature melting temperature is 820-860°C;

[0024] The high-temperature melting time is 12 to 14 minutes.

[0025] Preferably, the heating method is heating to boiling;

[0026] The heating time is 2 to 5 minutes.

[0027] Preferably, the density of the concentrated hydrochloric acid is 1.19 g / mL;

[0028] The mass ratio of the concentrated hydrochloric acid volume to the mixed flux is 20 mL: (5-6) g;

[0029] The leaching time is 1 minute.

[0030] Preferably, the dissolution rate of the ore sample is greater than or equal to 99%;

[0031] The step 3) specifically includes the following steps:

[0032] The leaching solution obtained in the above steps is heated again, and then tin dichloride solution is added to react. Then, after cooling, sodium tungstate solution is added, and titanium trichloride solution is added until the system turns blue. Subsequently, potassium dichromate solution is added until the system turns colorless. Then, sulfuric acid and phosphoric acid mixed and sodium diphenylamine sulfonate solution are added. Finally, titration is performed with potassium dichromate standard solution to obtain the amount of potassium dichromate standard solution. After calculation, the TFe content in the ore sample is obtained.

[0033] The present invention provides the use of anhydrous Na2CO3 in determining the total iron content of vanadium titanomagnetite using spent Na2O2; the determination method includes an alkali fusion method; the melting temperature of the alkali fusion method is 820-860°C. Compared with the prior art, the present invention addresses the problem that when sodium peroxide is exposed to air for a long time and becomes ineffective when measuring TFe melt samples in the alkali fusion method, the sample dissolution rate is only approximately 55%, seriously affecting work progress and greatly affecting the accuracy of inspection results. The present invention specifically combines anhydrous Na2CO3 with spent Na2O2 to determine the total iron content of vanadium titanomagnetite, and adopts a specific alkali fusion temperature, thereby ensuring the normal use of spent Na2O2 and achieving the same detection effect as normal Na2O2.

[0034] The present invention also provides a corresponding detection method and designs a method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2. By specifically setting the melting temperature at 820-860°C and combining it with the corresponding melting time, the sample dissolution rate is increased to more than 99%, solving the problem that sodium peroxide is difficult to be effectively utilized in a spent state. Through innovative technical means, the deep recycling of this waste in the field of fine analytical chemistry is achieved. This breakthrough not only broadens the channels for waste utilization, but also significantly improves the comprehensive utilization rate of resources, bringing huge economic value and social benefits to related industries. The present invention realizes the effective utilization of spent Na2O2 in the chemical analysis process, solving the problem of deep recycling of this substance in the field of fine analytical chemistry. This innovative breakthrough not only greatly broadens the channels for waste utilization, but also significantly improves the comprehensive utilization rate of resources, bringing extremely considerable economic value and social benefits to related industries.

[0035] Compared with the existing detection method, the present invention increases the mixed flux (anhydrous Na2CO3 + Na2O2) from 2.5 grams per piece to 5-6 grams per piece, and directly melts it in a high-temperature furnace at 820-860°C for 12-14 minutes. This improves the sample solubility from 55% to over 99%. Through innovative technical means, the present invention successfully solves the problem of sodium peroxide being difficult to effectively utilize in its spent state, and realizes the deep reuse of this waste in the field of fine analytical chemistry. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention provides a simplified process flow diagram of a method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2. DETAILED DESCRIPTION

[0037] To further understand the present invention, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] All raw materials of the present invention are not particularly limited in their sources and can be purchased from the market or prepared according to conventional methods well known to those skilled in the art.

[0039] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses analytically pure materials or materials of conventional purity required in the field of vanadium-titanium magnetite-total iron content detection.

[0040] The present invention provides the use of anhydrous Na2CO3 in determining the total iron content of vanadium-titanium magnetite by utilizing spent Na2O2.

[0041] In the present invention, the spent Na2O2 (Na2O2+NaOH+Na2CO3) is preferably such that the mass content of Na2O2 in the spent Na2O2 is preferably 60% to 80%, more preferably 63% to 77%, more preferably 65% ​​to 75%, and specifically 70%.

[0042] In the present invention, the spent Na2O2 further comprises one or more of water, NaOH, carbonic acid and sodium carbonate, more preferably NaOH and sodium carbonate.

[0043] In the present invention, the measuring method preferably includes an alkali fusion method.

[0044] In the present invention, the TFe grade of the vanadium-titanium magnetite is preferably 30% to 60%, more preferably 35% to 55%, and even more preferably 40% to 50%.

[0045] In the present invention, the application is preferably the application of anhydrous Na2CO3 and spent Na2O2 as a mixed flux.

[0046] In the present invention, the mass ratio of the anhydrous Na2CO3 to the spent Na2O2 is preferably 1:4, more preferably 1.5:3.5, and even more preferably 2:3.

[0047] In the present invention, the mass ratio of the vanadium-titanium magnetite sample to the mixed flux is preferably (0.1999-0.2001):(5-6), more preferably (0.19994-0.20006):(5.2-5.8), and more preferably (0.19998-0.20002):(5.4-5.6).

[0048] In the present invention, the melting temperature of the alkali fusion method is preferably 820-860°C, more preferably 825-855°C, more preferably 830-850°C, and most preferably 840°C.

[0049] The present invention provides a method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2, comprising the following steps:

[0050] 1) Mixing the ore sample and the mixed flux, placing them in a heating device, melting them at high temperature, and cooling them to obtain a frit;

[0051] The mixed flux includes spent Na2O2 and anhydrous Na2CO3;

[0052] 2) placing the frit obtained in the above step in water for reaction, then heating it, and then adding concentrated hydrochloric acid for leaching to obtain a leachate;

[0053] 3) The leaching solution obtained in the above step is subjected to a tin dichloride and titanium trichloride combined reduction-potassium dichromate titration method to calculate the TFe content in the ore sample.

[0054] The present invention first mixes an ore sample and a mixed flux and places the mixture in a heating device for high-temperature melting, followed by cooling to obtain a frit;

[0055] The mixed flux includes spent Na2O2 and anhydrous Na2CO3;

[0056] In the present invention, the ore sample preferably includes vanadium-titanium iron concentrate.

[0057] In the present invention, the TFe grade of the ore sample is preferably 30% to 60%, more preferably 35% to 55%, and even more preferably 40% to 50%.

[0058] In the present invention, the mass ratio of the ore sample to the mixed flux is preferably (0.1999-0.2001):(5-6), more preferably (0.19994-0.20006):(5.2-5.8), and even more preferably (0.19998-0.20002):(5.4-5.6). Specifically, it can be 0.2:(5-6).

[0059] In the present invention, the spent Na2O2 is specifically spent Na2O2, and the mass content of Na2O2 is preferably 60% to 80%, more preferably 63% to 77%, more preferably 65% ​​to 75%, and specifically 70%.

[0060] In the present invention, the mass ratio of the anhydrous Na2CO3 to the spent Na2O2 is preferably 1:4.

[0061] In the present invention, the high-temperature melting temperature is preferably 820-860°C, more preferably 825-855°C, more preferably 830-850°C, and most preferably 840°C.

[0062] In the present invention, the high-temperature melting time is preferably 12 to 14 minutes, more preferably 12.4 to 13.6 minutes, and even more preferably 12.8 to 13.2 minutes.

[0063] The present invention places the frit obtained in the above steps in water for reaction, then heats it, and then adds concentrated hydrochloric acid for leaching to obtain a leaching solution.

[0064] In the present invention, the heating method is preferably heating to boiling, specifically heating to boiling to remove H2O2.

[0065] In the present invention, the heating time is preferably 2 to 5 minutes, or 2.5 to 4.5 minutes, or 3 to 4 minutes.

[0066] In the present invention, the density of the concentrated hydrochloric acid is preferably 1.19 g / mL.

[0067] In the present invention, the mass ratio of the volume of concentrated hydrochloric acid to the mixed flux is preferably 20 mL: (5-6) g, more preferably 20 mL: (5.2-5.8) g, and even more preferably 20 mL: (5.4-5.6) g.

[0068] In the present invention, the leaching time is preferably 1 minute.

[0069] Finally, the present invention uses the leaching solution obtained in the above steps to adopt the tin dichloride and titanium trichloride combined reduction-potassium dichromate titration method to obtain the TFe content in the ore sample after calculation.

[0070] In the present invention, the dissolution rate of the ore sample is preferably greater than or equal to 99%.

[0071] In the present invention, the step 3) preferably comprises the following steps:

[0072] The leaching solution obtained in the above steps is heated again, and then tin dichloride solution is added to react. Then, after cooling, sodium tungstate solution is added, and titanium trichloride solution is added until the system turns blue. Subsequently, potassium dichromate solution is added until the system turns colorless. Then, sulfuric acid and phosphoric acid mixed and sodium diphenylamine sulfonate solution are added. Finally, titration is performed with potassium dichromate standard solution to obtain the amount of potassium dichromate standard solution. After calculation, the TFe content in the ore sample is obtained.

[0073] See also Figure 1 , Figure 1 The present invention provides a simplified process flow diagram of a method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2.

[0074] The present invention is to complete and refine the overall detection scheme, better ensure the accuracy of the detection effect, and further improve the utilization of failed Na2O2. The application of the above-mentioned anhydrous Na2CO3 in determining the total iron content of vanadium-titanium magnetite using failed Na2O2 (Na2O2+NaOH+Na2CO3) and a method for determining the total iron content of vanadium-titanium magnetite using failed Na2O2 can specifically include the following contents:

[0075] Weigh 0.1999-0.2001g of sample, accurate to 0.0001g, into a corundum crucible. Add 5-6g of a mixed flux: anhydrous Na2CO3 + spent Na2O2 (60%-80%) (1:4). Place in a muffle furnace at 820-860°C and melt for 12-14 minutes. Remove and cool, then place in a 300mL beaker filled with 50ml of hot water. After a vigorous reaction, heat and boil on a low-temperature electric furnace for 2-5 minutes until large bubbles appear (to drive off all the H2O2). Remove and cool slightly, then slowly add 20mL of concentrated hydrochloric acid (ρ=1.19g / mL) and soak for 1 minute. Rinse the crucible with hot water. Then, proceed with the steps of reduction, cooling, titration, and calculation of the TFe percentage.

[0076] Place the solution prepared above on an electric furnace and heat it to 60-70°C. Rinse the cup wall with a small amount of water while it is hot. Immediately add tin dichloride solution (15g / L) dropwise under stirring until it turns light yellow. Adjust the volume to about 150mL, control the temperature at 30°C, add 15 drops of sodium tungstate solution (250g / L), add titanium trichloride solution (1+19) dropwise until it turns blue, and then add potassium dichromate solution (1g / L) dropwise until it turns colorless (not counting). Immediately add 20mL of sulfur-phosphorus mixed acid (15+15+70), add 4 drops of sodium diphenylamine sulfonate solution (5g / L), and titrate with potassium dichromate standard solution (c(1 / 6K2Cr2O7)=0.05mol / L) to a stable purple color. Record the number of milliliters consumed (V). At the same time, do a blank test and record the number of milliliters consumed ( V 0) Calculate the percentage (%) of TFe in the sample based on the volume of the consumed potassium dichromate standard solution, the concentration of the potassium dichromate standard solution, and the weight of the sample.

[0077] The present invention provides the use of anhydrous Na2CO3 in determining the total iron content of vanadium titanomagnetite using spent Na2O2, as well as a method for determining the total iron content of vanadium titanomagnetite using spent Na2O2. The present invention specifically utilizes anhydrous Na2CO3 in combination with spent Na2O2 to determine the total iron content of vanadium titanomagnetite, and employs a specific alkali fusion temperature, thereby achieving the same detection effect as using normal Na2O2.

[0078] The present invention also provides a corresponding detection method and designs a method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2. By specifically setting the melting temperature at 820-860°C and combining it with the corresponding melting time, the sample dissolution rate is increased to more than 99%, solving the problem that sodium peroxide is difficult to be effectively utilized in a spent state. Through innovative technical means, the deep recycling of this waste in the field of fine analytical chemistry is achieved. This breakthrough not only broadens the channels for waste utilization, but also significantly improves the comprehensive utilization rate of resources, bringing huge economic value and social benefits to related industries. The present invention realizes the effective utilization of spent Na2O2 in the chemical analysis process, solving the problem of deep recycling of this substance in the field of fine analytical chemistry. This innovative breakthrough not only greatly broadens the channels for waste utilization, but also significantly improves the comprehensive utilization rate of resources, bringing extremely considerable economic value and social benefits to related industries.

[0079] Compared with the existing detection method, the present invention increases the mixed flux (anhydrous Na2CO3 + Na2O2) from 2.5 grams per piece to 5-6 grams per piece, and directly melts it in a high-temperature furnace at 820-860°C for 12-14 minutes. This improves the sample solubility from 55% to over 99%. Through innovative technical means, the present invention successfully solves the problem of sodium peroxide being difficult to effectively utilize in its spent state, and realizes the deep reuse of this waste in the field of fine analytical chemistry.

[0080] In order to further illustrate the present invention, the following examples describe in detail the application of anhydrous Na2CO3 provided by the present invention in determining the total iron content of vanadium-titanium magnetite using spent Na2O2 and a method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2. However, it should be understood that these examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. The scope of protection of the present invention is not limited to the following examples.

[0081] Example 1

[0082] Weigh 0.2g of sample, accurate to 0.0001g, and place it in a corundum crucible. Add 5-6g of mixed flux: anhydrous Na2CO3 + invalid Na2O2 (1:4), wherein the invalid Na2O2 contains Na2O2, NaOH and Na2CO3, and the effective mass content of Na2O2 is 70%. Place it in a muffle furnace at 840℃ and melt for 13 minutes. Remove it and cool it. Place it in a 300mL beaker filled with 50ml of hot water. After the violent reaction, place it on a low-temperature electric furnace and heat it to boil for 2-5 minutes until large bubbles appear (to drive away all H2O2). Remove it and cool it slightly. Slowly add 20mL of concentrated hydrochloric acid and soak it for 1 minute (hydrochloric acid, ρ1.19g / mL.) Then wash out the crucible with hot water. Place the solution prepared above on an electric stove and heat it to 65°C. Rinse the cup wall with a small amount of water while it is hot. Immediately add tin dichloride solution (15g / L) dropwise under stirring until it turns light yellow. Adjust the volume to about 150mL and control the temperature at 30°C. Add 15 drops of sodium tungstate solution (250g / L). Add titanium trichloride solution (1+19) dropwise until it turns blue. Then add potassium dichromate solution (1g / L) dropwise until it turns colorless (do not count). Immediately add 20mL of sulfur-phosphorus mixed acid (15 +15+70), add 4 drops of sodium diphenylamine sulfonate solution (5 g / L), and titrate with potassium dichromate standard solution (c(1 / 6K2Cr2O7)=0.05 mol / L) until it turns a stable purple color. Record the milliliters consumed (V). Simultaneously, perform a blank test and record the milliliters consumed (V0). Calculate the percentage (%) of TFe in the sample based on the volume of potassium dichromate standard solution consumed, the concentration of the potassium dichromate standard solution, and the weight of the sample.

[0083] Sample decomposition: Before improvement, the method was carried out in accordance with GB / 6730.65-2009 "Determination of total iron content of iron ore - Titanium trichloride reduction potassium dichromate titration (conventional method)", with a melting temperature of 700-750°C and a melting time of 5-10 minutes.

[0084] The test results before and after the improvement are shown in Tables 1 and 2. Standard samples of vanadium-titanium iron concentrate 3#YSBC19729-2013 (TFe: 34.56%) and vanadium-titanium iron concentrate 2#YSBC19725-2014 (TFe: 53.73%) were used for parallel determination and analysis.

[0085] Table 1 Test analysis results before improvement

[0086]

[0087] Table 2 Improved test results

[0088]

[0089] Experimental results: The flux amount was increased from 2.5 g / piece (sodium peroxide + anhydrous sodium carbonate) in GB / 6730.65-2009 to 5-6 g / piece, and the melting time was changed to (12-14 minutes / piece). It was determined that the muffle furnace can melt iron ore with a grade of more than 30% at around 840°C, and the analysis results are also accurate.

[0090] The above describes in detail the use of anhydrous Na2CO3 in the determination of the total iron content of vanadium titanomagnetite using spent Na2O2 (Na2O2 + NaOH + Na2CO3) provided by the present invention, as well as a method for determining the total iron content of vanadium titanomagnetite using spent Na2O2. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above examples is intended only to help understand the method and core concept of the present invention, including the best mode, and also to enable any person skilled in the art to practice the present invention, including making and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, without departing from the principles of the present invention, various improvements and modifications may be made to the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be imagined by those skilled in the art. If these other embodiments have structural elements similar to the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. Application of anhydrous Na2CO3 in the determination of total iron content of vanadium titanomagnetite using spent Na2O2; The determination method includes an alkali fusion method; The melting temperature of the alkali fusion method is 820-860°C.

2. The use according to claim 1, characterized in that The failed Na2O2 specifically refers to failed Na2O2, in which the mass content of Na2O2 is 60% to 80%; The TFe grade of the vanadium-titanium magnetite is 30% to 60%.

3. The use according to claim 2, characterized in that The application is specifically the application of anhydrous Na2CO3 and spent Na2O2 as a mixed flux; The mass ratio of the anhydrous Na2CO3 to the spent Na2O2 is 1:4; The mass ratio of the vanadium-titanium magnetite sample to the mixed flux is (0.1999-0.2001):(5-6).

4. A method for determining the total iron content of vanadium-titanium magnetite using spent Na2O2, characterized in that: The following steps are involved: 1) Mixing the ore sample and the mixed flux, placing them in a heating device, melting them at high temperature, and cooling them to obtain a frit; The mixed flux includes spent Na2O2 and anhydrous Na2CO3; 2) placing the frit obtained in the above step in water for reaction, then heating it, and then adding concentrated hydrochloric acid for leaching to obtain a leachate; 3) The leaching solution obtained in the above step is subjected to a tin dichloride and titanium trichloride combined reduction-potassium dichromate titration method to calculate the TFe content in the ore sample.

5. The method according to claim 4, characterized in that The ore sample includes vanadium-titanium iron concentrate; The TFe grade of the ore sample is 30% to 60%; The mass ratio of the ore sample to the mixed flux is (0.1999-0.2001):(5-6).

6. The method according to claim 4, characterized in that The failed Na2O2 specifically refers to failed Na2O2, in which the mass content of Na2O2 is 60% to 80%; The mass ratio of the anhydrous Na2CO3 to the spent Na2O2 is 1:

4.

7. The method according to claim 4, characterized in that The high temperature melting temperature is 820-860°C; The high-temperature melting time is 12 to 14 minutes.

8. The method according to claim 4, characterized in that The heating method is heating to boiling; The heating time is 2 to 5 minutes.

9. The method according to claim 4, characterized in that The density of the concentrated hydrochloric acid is 1.19 g / mL; The mass ratio of the concentrated hydrochloric acid volume to the mixed flux is 20 mL: (5-6) g; The leaching time is 1 minute.

10. The method according to claim 4, characterized in that The dissolution rate of the ore sample is greater than or equal to 99%; The step 3) specifically includes the following steps: The leaching solution obtained in the above steps is heated again, and then tin dichloride solution is added to react. Then, after cooling, sodium tungstate solution is added, and titanium trichloride solution is added until the system turns blue. Subsequently, potassium dichromate solution is added until the system turns colorless. Then, sulfuric acid and phosphoric acid mixed and sodium diphenylamine sulfonate solution are added. Finally, titration is performed with potassium dichromate standard solution to obtain the amount of potassium dichromate standard solution. After calculation, the TFe content in the ore sample is obtained.

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