Method for improving Fe < 2 + > detection precision by decarburization through magnetic separation method

Abstract

The invention relates to a method for improving Fe < 2 + > detection precision by decarburization through a magnetic separation method. The method comprises the following steps: weighing a detection sample; carrying out magnetic separation on the weighed sample by using a small high-intensity magnetic separator, and separating carbon from iron minerals by virtue of magnetic difference through separation of the magnetic separator; determining the ratio of iron minerals to carbon content in the sample; measuring the ferrous content of the separated iron mineral sample by a potassium dichromate volumetric method; calculating the ferrous content in the whole sample according to the determined proportion of the iron mineral content to the carbon content in the sample; according to the method, the carbon in the test sample is abandoned in advance through the magnetic separation process, so that the titration end point of the potassium dichromate volumetric method is determined more accurately, the detection process is simple and easy to operate, and the accuracy of the test result of the Fe < 2 + > content of the carbonaceous iron minerals is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of mineral processing methods in the field of chemical element testing technology, in particular to a method for improving Fe 2+ Methods for testing accuracy. Background Art

[0002] Iron is a common element in minerals, and Fe 2+ Detection is a daily task in chemical testing. Usually, the potassium dichromate volumetric method is used to determine the ferrous content. The titration end point is reached when the potassium dichromate standard solution is titrated to a stable purple color. The titration amount is then substituted into the formula to calculate the ferrous content. However, when carrying out work, carbon-containing iron compounds such as blast furnace ash and blast furnace sludge are often encountered. When determining the ferrous content, the liquid in the conical flask for dissolving the sample appears black and gray due to the carbon content, and it is difficult to determine the titration end point. In the process of chemical testing, other elements in the sample may affect the titration results of the target element after dissolution. This requires us to find a way to remove the elements that affect the test results.

[0003] The Chinese patent with publication number CN117741041A discloses an analytical method for determining the content of iron in ferromanganese by potassium dichromate volumetric method, comprising: placing the weighed sample in a conical flask, adding nitric acid, phosphoric acid, and sulfuric acid, heating and dissolving until sulfuric acid smoke is emitted, removing it, cooling it slightly, adding hydrochloric acid, and shaking it well; heating and boiling, reducing it to light yellow with tin dichloride solution while hot, removing it and cooling it slightly, and then adding a certain amount of water; adding sodium tungstate solution, reducing it to a stable blue with titanium trichloride solution, adding sulfuric acid and phosphoric acid, dropping potassium dichromate solution until the blue disappears, immediately adding sodium diphenylamine sulfonate solution, and titrating it to a stable purple color with potassium dichromate standard titration solution as the end point. The present invention provides an analytical method for determining the content of iron in ferromanganese by potassium dichromate volumetric method, which has been used in production practice, has a simple and rapid determination process, and has accurate results. It is a very effective and practical method; but the patent is aimed at carbon-containing iron compounds in this application, and the use of this method still cannot solve the disadvantage that the carbon element liquid is black-gray in the determination process in this application, and it is difficult to determine the end point of the titration. Summary of the invention

[0004] The present invention provides a method for improving Fe by decarburization using a magnetic separation method. 2+ The method of testing accuracy can better dissolve the test sample, make it easier to determine the ferrous titration endpoint of carbon-containing iron compounds, and improve the Fe 2+ detection accuracy.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method of decarburization to increase Fe 2+ The method for checking accuracy includes the following steps:

[0007] S1. Weigh the test sample;

[0008] S2. Use a small strong magnetic separator to magnetically separate the symmetrically taken samples, and use the magnetic difference to separate the carbon and iron minerals through the strong magnetic separator;

[0009] S3, determining the percentage of the separated iron minerals and carbon in the sample;

[0010] S4. Determine the ferrous content of the selected iron mineral samples by potassium dichromate volumetric method;

[0011] S5. Calculate the ferrous content in the whole sample based on the ratio of iron minerals to carbon content detected after strong magnetic separation of the sample.

[0012] Furthermore, in step S1, 0.2 to 2 g of the test sample is weighed.

[0013] Furthermore, the small strong magnetic separator is selected from 5000×10 2 ~15000×10 2 High-strength magnetic separator with a field strength of amperes / meters.

[0014] Furthermore, when determining the ferrous iron content in step S4, the end point is titration with a potassium dichromate standard titration solution until a stable purple color is obtained.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The magnetic separation process discards the carbon in the test sample in advance, so as to more accurately determine the endpoint of potassium dichromate volumetric titration. The detection process is simple and easy to operate. 2+ The content greatly improves the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0019] See Figure 1 , which is a schematic diagram of the structure of the present invention. The present invention utilizes a magnetic separation method to decarburize and increase Fe 2+ The method for checking accuracy includes the following steps:

[0020] S1. Because the amount of sample weighed during the test is very small, if the carbon content of the test sample is known in advance, weigh 0.2 to 2g of the test sample. If the carbon content of the test sample is unclear, weigh 2g of the test sample.

[0021] S2, use 5000×102 ~15000×10 2 A small high-intensity magnetic separator with a field strength of amperes / meters is used to perform magnetic separation on symmetrically taken samples. Carbon is a non-magnetic mineral, while iron minerals are strong or medium magnetic minerals. The magnetic difference is used to separate carbon from iron minerals through the magnetic separator, and the iron minerals are recovered and the carbon mixed in is discarded.

[0022] S3. Determine the percentage of separated iron minerals and carbon in the sample.

[0023] S4. After dissolution of carbon-containing iron minerals, the sample liquid will appear dark gray. The inspectors cannot accurately determine the titration end point. The ferrous content of the symmetrically taken iron mineral samples is determined by the "potassium dichromate volumetric method". Because the carbon in the sample has been sorted out before, the subsequent dissolved sample liquid is almost transparent instead of the previous dark gray due to the discarding of the carbon in the original sample. The potassium dichromate standard titration solution is titrated to a stable purple color as the end point. Therefore, it is easy for inspectors to determine the titration end point and improve the accuracy of the test results. The recovery rate of iron minerals by the strong magnetic separator is close to 100%, and the sorting does not affect the test results of ferrous iron.

[0024] S5. After the ferrous content in the iron mineral is detected, it is converted according to the weight ratio of the iron mineral to carbon to obtain the ferrous content in the original sample.

[0025] The following examples are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[0026] [Example]

[0027] S1. Weigh 0.5g of sediment sample;

[0028] S2, use 10000×10 2 The sample was magnetically separated by a small wet high-intensity magnetic separator with a field strength of ampere / meter, and 0.398g of iron minerals and 0.102g of carbon were obtained;

[0029] S3. Determine that iron minerals account for 79.60% of the total weight of the sample;

[0030] S4. The ferrous content of the iron mineral was detected by potassium dichromate volumetric method, and the ferrous content of the iron mineral was 16.835%;

[0031] S5. Since iron minerals account for 79.60% of the original sample weight, the ferrous content of the original sample is determined to be 13.40% (16.835%×0.796).

Claims

1. A method of decarburization to increase Fe 2+ A method for checking accuracy, characterized in that The steps include: S1. Weigh the test sample; S2. Use a small strong magnetic separator to magnetically separate the symmetrically taken samples, and use the magnetic difference to separate the carbon and iron minerals through the strong magnetic separator; S3, determining the percentage of the separated iron minerals and carbon in the sample; S4. Determine the ferrous content of the selected iron mineral samples by potassium dichromate volumetric method; S5. Calculate the ferrous content in the whole sample based on the ratio of iron minerals to carbon content detected after strong magnetic separation of the sample.

2. A method of decarburizing and increasing Fe by magnetic separation according to claim 1 2+ The method for checking accuracy is characterized in that In the step S1, 0.2 to 2 g of the test sample is weighed.

3. A method of decarburizing and increasing Fe by magnetic separation according to claim 1 2+ The method for checking accuracy is characterized in that The small strong magnetic separator is selected 5000×10 2 ~15000×10 2 High-strength magnetic separator with a field strength of amperes / meters.

4. A method of decarburizing and increasing Fe by magnetic separation according to claim 1 2+ A method for checking accuracy, characterized in that When the ferrous iron content is determined in step S4, the end point is that the potassium dichromate standard titration solution is titrated until the color stabilizes in purple.

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