Search

CN-122017125-A - Method for detecting chloride ion content in blast furnace gas and gas sampling device

CN122017125ACN 122017125 ACN122017125 ACN 122017125ACN-122017125-A

Abstract

The invention relates to a method for detecting the content of chloride ions in blast furnace gas and a gas sampling device. The strongly reducing and interfering sulfide ions are then all oxidized to undisturbed sulfate ions, while carbonate ions are removed. And then calculating the mass of chloride ions in the absorption liquid according to the absorption liquid and the blank titration result. And finally, calculating the chlorine content in the blast furnace gas according to the collected coal gas volume and the measured chlorine ion mass. The invention effectively avoids the interference of other ions in the absorption liquid on the subsequent titration result, and ensures the detection accuracy.

Inventors

  • ZHANG TAO
  • SHAO JIUGANG
  • MAO RUI
  • SU HANG
  • LI XIANXIANG

Assignees

  • 江苏省沙钢钢铁研究院有限公司
  • 江苏沙钢集团有限公司
  • 江苏沙钢钢铁有限公司

Dates

Publication Date
20260512
Application Date
20260310

Claims (8)

  1. 1. A method for detecting the content of chloride ions in blast furnace gas is characterized by comprising the following steps: Step S1, will The absorption bottles are connected in series, Is an integer and More than or equal to 2, one end of the gas sampling tube extends into the first absorption bottle, and the other end of the gas sampling tube is communicated with the gas pipeline through the gas sampling port, the first The absorption bottles are communicated with the drying bottle, and a gas flowmeter is arranged on a connecting pipeline at the outlet of the drying bottle; step S2, at 1 st to 1 st The prepared sodium carbonate solution is contained in the absorption bottle, the first Silver nitrate solution is contained in each absorption bottle; Step S3, introducing blast furnace gas into the absorption bottle for sampling, and recording sampling starting time First, the Sampling time of each absorption bottle Blast furnace gas flow rate ; Step S4, after the sampling is finished All the sodium carbonate solution in the absorption bottles is transferred to the conical flask, and deionized water is adopted to wash the absorption bottles after transferring the sodium carbonate solution for a plurality of times, and the washed deionized water is continuously transferred to the conical flask; S5, acidizing pretreatment is carried out on the solution in the conical flask until the pH value of the solution is reduced to be neutral or weak acid, the conical flask is heated, and the solution is cooled to room temperature after being continuously heated for a preset time; Step S6, adding hydrogen peroxide into the solution subjected to the acidification pretreatment, and performing oxidation treatment until bubbles are not continuously generated in the solution, so that oxidation is completed; step S7, continuously heating the conical flask until the excessive oxidant is completely decomposed, and cooling the solution to room temperature; step S8, dropwise adding a dilute nitric acid solution into the conical flask, and adjusting the pH value of the solution to 7-10; Step S9, performing absorption liquid titration on the solution with the pH value adjusted in the step S8, adding potassium chromate solution into the solution as an indicator, performing titration by using silver nitrate standard titration liquid with known accurate concentration, and recording the volume of the silver nitrate standard titration liquid consumed at the end of titration ; Step S10, performing blank titration on the solution with the pH value adjusted in the step S8, adding potassium chromate solution as an indicator into the solution, adding calcium carbonate powder until the solution is in a turbid state, performing titration by using silver nitrate standard titration solution with known accurate concentration, and recording the volume of the silver nitrate standard titration solution consumed at the end point of titration ; Step S11, calculating the mass of chloride ions, wherein the calculation formula is as follows (1) In the formula (1), The unit is mol/L for the concentration of silver nitrate standard titration solution, The molar mass of the chlorine is specifically 35.45g/mol; step S12, based on the data acquired in the step S3, combining the mass of chloride ions calculated in the step S11, and finally calculating to obtain the chlorine content in the blast furnace gas, wherein a calculation formula of the chlorine content is as follows (2) In the formula (2), The unit of chlorine content in the blast furnace gas is mg/m3, The mass of chloride ions calculated for formula (1), in mg, The unit is L/min for blast furnace gas flow, To begin the sampling time, in minutes, Is the first Sampling time of each absorption bottle is in min.
  2. 2. The method for detecting the chloride ion content in the blast furnace gas according to claim 1, wherein in the step S2, the concentration of the prepared sodium carbonate solution is 0.05 mol/L and the concentration of the silver nitrate solution is 0.005mol/L.
  3. 3. The method for detecting chloride ion content in blast furnace gas according to claim 1, wherein in step S5, the step of acidizing the solution in the conical flask is performed, Step S51, adding dilute nitric acid or dilute sulfuric acid into the conical flask dropwise; Step S52, adding phenolphthalein as an indicator into the conical flask, and gently shaking the conical flask until the pH value of the solution is reduced to 6-7; and step S53, placing the conical flask on an electric heating plate or a water bath for heating, setting the heating temperature to be 60-80 ℃, continuously heating for 10-15 min, and then cooling to room temperature.
  4. 4. The method for detecting the chloride ion content in the blast furnace gas according to claim 1, wherein in the step S6, 30% hydrogen peroxide is slowly added dropwise to the solution subjected to the acidification pretreatment, and the solution is gently stirred or shaken, and bubbles are generated in the process of adding the hydrogen peroxide, and the dropwise addition is continued until no bubbles are generated in the solution.
  5. 5. The method for detecting the chloride ion content in the blast furnace gas according to claim 1, wherein in the step S7, the conical flask is placed on an electric plate or a water bath for heating, the heating temperature is set to be 60-80 ℃, the heating is continued for 10-15 min, and then the conical flask is cooled to room temperature.
  6. 6. The method for detecting the chloride ion content in the blast furnace gas according to claim 1, wherein in the step S9, 1mL of 50g/L potassium chromate is added into the solution with the pH value adjusted in the step S8 as an indicator, the solution is yellow, the titration is carried out by adopting a silver nitrate standard titration solution with accurate concentration, the conical flask is continuously shaken after the titration is continuously carried out until the solution has stable pale reddish brown sediment, the pale reddish brown does not fade any more, and the titration end point of the absorption solution titration is the moment.
  7. 7. The method for detecting the chloride ion content in the blast furnace gas according to claim 1, wherein in the step S10, 1mL of 50g/L potassium chromate is added into the solution with the pH value adjusted in the step S8, the calcium carbonate powder is continuously added until the solution is in a turbid state, the titration is carried out by using a silver nitrate standard titration solution with a known accurate concentration, the conical flask is continuously shaken until the solution is subjected to light reddish brown precipitation, the light reddish brown is not faded any more, and the titration end point of the blank titration is the moment.
  8. 8. A gas sampling device for the method for detecting the chloride ion content in blast furnace gas according to any one of claims 1-7 is characterized by comprising a plurality of absorption bottles, wherein porous glass plates are arranged in the absorption bottles, the absorption bottles are connected in series, and adjacent bottle bodies are communicated through a connecting pipeline; the tail absorption bottle is communicated with the drying bottle through a connecting pipeline, and a gas flowmeter is arranged on the connecting pipeline at the outlet of the drying bottle; and filling silver nitrate solution into the tail absorption bottle, and filling sodium carbonate solution into the rest absorption bottles, wherein the concentration of the sodium carbonate solution is 0.05mol/L, and the concentration of the silver nitrate solution is 0.005mol/L.

Description

Method for detecting chloride ion content in blast furnace gas and gas sampling device Technical Field The invention relates to a method for detecting the content of chloride ions in blast furnace gas and a gas sampling device, and belongs to the technical field of gas chloride ion determination. Background In the process of purifying and utilizing blast furnace gas, hydrogen chloride (HCl) and ammonium chloride are added) The chlorides are key factors that cause corrosion of equipment and degradation of product quality. The substances can be separated out to form a strong corrosive solution in the gas conveying and cooling processes, so that the safe and stable operation of systems such as a gas pipeline, a TRT power generation device, a hot blast stove and the like is seriously endangered. At present, a solution absorption method is generally adopted in the industry to measure the content of chloride ions so as to evaluate risks, and the characteristic that the chloride ions are easily dissolved in water is utilized to absorb the chloride ions in the gas by using alkali liquor or deionized water, and then the gas is detected by a titration method or an ion chromatography method. If sodium hydroxide and other strong alkali solutions are used as the absorption liquid, the absorption liquid can absorb target chloride and simultaneously can also react with a large amount of hydrogen sulfide existing in the gas) And carbon dioxide%) A non-negligible competing reaction occurs.React with alkali liquor to generate carbonate radical) And bicarbonate radical),Then converted into sulfide ion) These reaction products can cause serious interference with subsequent chloride ion determinations. It is apparent that the above-described alkaline solution absorption assay lacks an efficient and standardized procedure for removing interferents. The existing method has the defects that the manual heating oxidation method is difficult to accurately control the reaction condition, so that the removal of the interfering substances is incomplete, the pH value of the solution is rough in the adjustment process, the accuracy of the titration end point judgment is directly affected, and in addition, although the ion selective electrode method has certain application, the pH value is required to be repeatedly adjusted, the electrode is required to be cleaned to be in a stable state, the process is complicated, the stability is insufficient, and the detection result cannot truly reflect the total chlorine content. The application with publication No. CN120294241A discloses a method for measuring chloride ion content in gas, which comprises the steps of absorbing chloride ions in gas by ultrapure water, then titrating the chloride ion content in solution by using a Morse method, and finally calculating the chloride ion content in the gas, wherein the method has two defects, namely firstly, the efficiency of absorbing the chloride ions by using the ultrapure water is lower, the actual detection result is lower, secondly, the absorption liquid is not pretreated before titration, and the sampling process is carried outAndAlso dissolved in water and also interfere with the titration results during the assay. In view of this, it is desirable to provide a full-flow analysis method capable of achieving absorption and thorough impurity removal to improve accuracy and precision of chlorine concentration detection in blast furnace gas, and to be operable under conventional chemical analysis laboratory conditions. Disclosure of Invention The invention provides a method for detecting the content of chloride ions in blast furnace gas and a gas sampling device, which solve the problems of instability and dependence on expensive detection equipment in the conventional method for detecting the chloride ions in the gas, can objectively and accurately determine the content of the chloride ions in the gas, and are suitable for detecting the gas in a conventional chemical laboratory on a production site. The technical scheme adopted for solving the technical problems is as follows: a method for detecting the content of chloride ions in blast furnace gas comprises the following steps: Step S1, will The absorption bottles are connected in series,Is an integer andMore than or equal to 2, one end of the gas sampling tube extends into the first absorption bottle, and the other end of the gas sampling tube is communicated with the gas pipeline through the gas sampling port, the firstThe absorption bottles are communicated with the drying bottle, and a gas flowmeter is arranged on a connecting pipeline at the outlet of the drying bottle; step S2, at 1 st to 1 st The prepared sodium carbonate solution is contained in the absorption bottle, the firstSilver nitrate solution is contained in each absorption bottle; Step S3, introducing blast furnace gas into the absorption bottle for sampling, and recording sampling starting time First, theSampling time of each absor