Method for measuring content of zinc in zinc slag

Abstract

The invention discloses a method for measuring the zinc content of zinc slag, which comprises the following steps: when zinc slag appears on the surface of zinc liquid, averagely delimiting N areas, fishing out the zinc slag, pressing the zinc slag into slices with the thickness of less than 0.5 mm by using pliers, and numbering for later use; the method comprises the following steps: determining elements except zinc in the zinc slag according to a coating process, and preparing a spectrum analyzer mixed high-standard solution containing the elements; respectively shearing and weighing the N taken zinc slag samples by using a pair of scissors; heating and dissolving the zinc slag sample by using a nitric acid solution with a certain concentration until the zinc slag sample is transparent, and fixing the volume into a volumetric flask by using pure water; the spectrum analyzer establishes a determined element and concentration analysis method for detection and obtains an arithmetic mean value of N groups of data; and subtracting the detection result of each element by 100% to obtain the zinc content in the zinc slag. The method can accurately analyze the zinc content in the zinc slag, truly and objectively evaluate the value of the zinc slag, and improve the auction price; the trend of various elements in the zinc liquid is analyzed and researched, and the zinc liquid components are stably controlled.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a method for determining the zinc content of zinc slag, and specifically to the detection of the zinc content of waste zinc slag in a continuous hot-dip galvanizing production line. Background Art

[0002] The zinc content of the waste zinc slag produced by the continuous hot-dip galvanizing production line of Baosteel's rare earth steel cold-rolled sheet plant is relatively high. Theoretically, it should be above 90%. However, when it is sent to relevant testing agencies, the testing deviation is large, and the test value fluctuates greatly between 60-99%. If the buyer conducts the test himself, there is no feedback data. In this way, the quality of the zinc slag cannot be accurately and objectively evaluated, and the initiative of the auction cannot be fully in one's hands. In addition, accurate analysis of the content of each element in the zinc slag is of great significance to the stable control of the composition of the zinc liquid.

[0003] Document 1 discloses a method for detecting the zinc content in a benzene hydrogenation catalyst, which mainly uses a chemical titration method, has many operation steps, and requires a lot of calculations. The main field of this patent is the detection of the zinc content of zinc slag produced in zinc liquid during hot-dip galvanizing. The equipment is a spectrometer, the method uses a residual method, and the operation process is simple.

[0004] Document 2 discloses a method for rapid on-site detection of heavy metals copper, zinc, lead and cadmium in seawater, which uses square wave anodic stripping voltammetry and an electrochemical analyzer, and has many operating steps. The advantages of this patent are convenient and fast operation and high precision.

[0005] Document 3 discloses a method for detecting free zinc ions, which requires both instrument detection and chemical titration during the operation process. The advantage of this patent is that it uses a spectrometer for direct detection, which can be completed by removing the simple calculation of impurity content. Summary of the invention

[0006] The purpose of the present invention is to provide a method for determining the zinc content of zinc slag, accurately analyze the zinc content in the zinc slag, truly and objectively evaluate the value of the zinc slag, and improve the auction price; analyze and study the trends of various elements in zinc liquid, and stably control the composition of zinc liquid.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for determining zinc content in zinc slag according to the present invention comprises the following steps:

[0009] 1) Sampling is performed when the zinc slag is just taken out and is still in a molten state; when zinc slag appears on the surface of the zinc liquid, the zinc slag is evenly demarcated in N areas to be fished out, and the zinc slag is pressed into thin slices with a thickness of less than 0.5 mm with pliers, and numbered for later use;

[0010] 2) Determine the elements other than zinc contained in the zinc slag according to the coating process, and prepare a spectrometer mixed high-standard solution containing these elements;

[0011] 3) Use scissors to cut and weigh the N zinc slag samples respectively;

[0012] 4) Heat and dissolve the zinc slag sample with a certain concentration of nitric acid solution until it becomes transparent, and then dilute it to a volumetric flask with pure water;

[0013] 5) The spectrum analyzer establishes the element and concentration analysis method determined in the above step 2) to perform detection and calculate the arithmetic mean of N groups of data;

[0014] 6) Subtract the test results of each element from 100% to obtain the zinc content in the zinc slag.

[0015] Furthermore, when zinc slag appears on the surface of the zinc liquid, 5 to 7 areas are designated on average to remove the zinc slag.

[0016] Furthermore, when zinc slag appears on the surface of the zinc liquid, 6 areas are designated on average to remove the zinc slag.

[0017] Furthermore, N zinc slag samples were sheared with scissors and weighed to 0.2±0.0002 g.

[0018] Furthermore, the zinc slag sample was heated and dissolved with a 35% nitric acid solution until it became transparent.

[0019] Further, dilute to 100 ml in a volumetric flask with pure water.

[0020] Further, the zinc slag sample was dissolved in a 35% nitric acid solution and placed on a heating plate at 260-300° C. until the solution became transparent.

[0021] Compared with the prior art, the beneficial technical effects of the present invention are:

[0022] 1. The test results are accurate and can truly and objectively evaluate the value of zinc slag, so that we can have a clear idea of ​​it, increase the auction price and obtain higher profits.

[0023] 2. Accurately detect the content of various elements in zinc slag, which provides important data reference for us to analyze and study the trend of various elements in zinc liquid, so as to stably control the composition of zinc liquid and improve the quality of galvanizing.

[0024] 3. The price of zinc slag auction in 2021 is 15,227 yuan / ton, and the price of zinc slag auction in 2023 is 17,189 yuan / ton, with a price difference of 1,962 yuan / ton. The average price of zinc ingots in the same period of 2021 is 21,912 yuan / ton, and the average price of zinc ingots in the same period of 2023 is 19,875 yuan / ton. The price of zinc ingots is actually falling. According to the annual production of 756 tons of zinc slag in 2023, the economic benefit is: 756*1962=1.4832 million yuan. DETAILED DESCRIPTION

[0025] A method for determining zinc content in zinc slag specifically comprises the following steps:

[0026] 1) Sample the zinc slag produced in the molten state from the four corners of the zinc pot and the six areas before and after the sinking roller. The specific operation method is to first scoop the zinc slag into the slag trough, and then use pliers to press the zinc slag into thin sheets with a thickness of less than 0.5mm, and number them for later use.

[0027] 2) The main process of the galvanizing production line is zinc-aluminum-antimony hot-dip galvanizing, in which the aluminum content in the zinc solution is controlled at 0.2%, the antimony content is controlled at 0.011%, and the iron content is controlled not higher than 0.03%. The zinc ingots added in production contain not only zinc, but also trace elements with extremely low contents of iron, lead, tin, cadmium and copper. In this way, it can be determined that the elements other than zinc in the zinc slag are aluminum, iron, antimony, lead, tin, copper and cadmium, and then a mixed high-standard solution for the spectrometer is prepared, and the concentrations are set at Al-6ppm, Fe-0.4ppm, Sb-0.4ppm, Pb-0.4ppm, Cu-0.4ppm, Sn-0.4ppm, and Cd-0.4ppm respectively.

[0028] 3) Use scissors to cut the 6 zinc slag samples and weigh them to 0.2±0.0002g respectively.

[0029] 4) Dissolve the zinc slag sample with 35% nitric acid solution, place it on a heating plate at 260-300°C until the solution becomes transparent, and dilute it to 100ml in a volumetric flask with pure water.

[0030] 5) The spectrum analyzer establishes the element and concentration analysis method mentioned in 2 above to detect and calculate the arithmetic mean of the 6 sets of data.

[0031] 6) Subtract the test results of each element from 100% to obtain the zinc content in the zinc slag.

[0032] The following is the data of the zinc slag test on the galvanizing production line of the rare earth steel cold-rolled plate plant in August 2022. The final zinc content in the zinc slag was detected to be 97.86%.

[0033] Table 1 Detection and analysis data of zinc content in zinc slag

[0034] element Al Fe Sb Pb Cd Cu Sn Zn content / % 1.303 0.807 0.015 0.005 0.001 0.005 0.003 97.861

[0035] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for determining zinc content in zinc slag, characterized in that: The steps include: 1) Sampling is performed when the zinc slag is just taken out and is still in a molten state; when zinc slag appears on the surface of the zinc liquid, the zinc slag is evenly demarcated in N areas to be fished out, and the zinc slag is pressed into thin slices with a thickness of less than 0.5 mm with pliers, and numbered for later use; 2) Determine the elements other than zinc contained in the zinc slag according to the coating process, and prepare a spectrometer mixed high-standard solution containing these elements; 3) Use scissors to cut and weigh the N zinc slag samples respectively; 4) Heat and dissolve the zinc slag sample with a certain concentration of nitric acid solution until it becomes transparent, and then dilute it to a volumetric flask with pure water; 5) The spectrum analyzer establishes the element and concentration analysis method determined in the above step 2) to perform detection and calculate the arithmetic mean of N groups of data; 6) Subtract the test results of each element from 100% to obtain the zinc content in the zinc slag.

2. The method for measuring zinc content in zinc slag according to claim 1, wherein: When zinc slag appears on the surface of the zinc liquid, 5 to 7 areas are designated on average to remove the zinc slag.

3. The method for measuring zinc content in zinc slag according to claim 2, wherein: When zinc slag appears on the surface of the zinc liquid, 6 areas are evenly designated to remove the zinc slag.

4. The method for measuring zinc content in zinc slag according to claim 1, wherein: Use scissors to cut N zinc slag samples and weigh them to 0.2±0.0002g respectively.

5. The method for determining zinc content in zinc slag according to claim 1 or 4, characterized in that: Use 35% nitric acid solution to heat and dissolve the zinc slag sample until it becomes transparent.

6. The method for measuring zinc content in zinc slag according to claim 5, wherein: Add pure water to a 100 ml volumetric flask.

7. The method for determining zinc content in zinc slag according to claim 5, wherein: Dissolve the zinc slag sample in 35% nitric acid solution and place it on a heating plate at 260-300°C until the solution becomes transparent.