An inhibitor for treating the caking of filter media in the bottom filter tank of blast furnace slag granulation, its usage method and uses

Abstract

The present invention provides an inhibitor for treating the caking of filter media in the bottom filter tank of a blast furnace slag granulation system, which comprises ethylenediaminetetra(methylenephosphonic acid) and / or its sodium salt, alkali metal salts of polycarboxylic acids, polyaspartic acid, caustic alkali, acrylic acid copolymers and synergists. The present invention also provides a method of using and applications of the above inhibitor. The inhibitor of the present invention can decompose the caked plates, achieving the purpose of gradually dissolving and softening the caked plates. At the same time, it can improve the water permeability of the bottom filter tank, making the entire slag granulation system tend to develop in a benign manner, delay caking, extend the replacement cycle of filter media, save the cost of replacing the filter media in the bottom filter tank, and increase the service time of the bottom filter tank.

Description

Technical Field

[0001] The present invention belongs to the field of polymerization inhibitors, and particularly relates to a polymerization inhibitor for treating the caking of filter materials in the bottom filter tank of blast furnace slag granulation, its use method and applications. Background Art

[0002] During the smelting of blast furnaces, high-temperature liquid slag (1350°C - 1500°C) is generated. The annual production of high-temperature liquid slag from molten iron in China is approximately 280 million tons. At home and abroad, the precipitation filtration method (commonly known as the bottom filtration method) water slag process is usually used to treat the molten slag. Hydraulic slag granulation is carried out in front of the blast furnace. After the molten slag is broken by water quenching, it becomes a loose slag-water mixture (commonly known as water slag), and the water slag enters the bottom filter tank through the slag flushing channel. The filter layer at the bottom of the bottom filter tank is usually composed of filter materials with gradually increasing particle sizes from top to bottom. Liquid water passes through multiple layers of filter materials in the bottom filter tank, leaving solid wet slag particles on the top of the filter materials in the bottom filter tank, and then the slag particles are grabbed by a bridge grab crane and loaded onto a truck for external transportation. The slag particles (particle size 0.2mm - 3mm) obtained after water quenching have a wide range of uses and can be used as cement raw materials, heat insulation fillers, etc., making full use of the slag.

[0003] The blast furnace slag water contains a certain amount of slag wool. During the filtration process of realizing slag-water separation, the slag wool easily blocks the filtration gaps of the filter layer, and long-term action will cause the filter layer to cake. The caked filter layer loses its filtration function, reducing the water flow rate of the bottom filter tank, affecting the normal slag granulation of the blast furnace, and causing the entire system to be unable to handle the quenched slag water normally. Seriously, it may lead to forced blast furnace shutdown, bringing greater economic losses to the enterprise.

[0004] Currently, for the problem of caking of the filter materials in the bottom filter tank, one approach is to add an anti-caking agent to the slag water to delay the occurrence of caking of the filter materials in the bottom filter tank and extend the stable operation time of the system. For the filter materials in the bottom filter tank that have been severely caked, one solution is to regularly replace the filter materials in the bottom filter tank to ensure the water flow rate of the bottom filter tank slag water. This method can only relieve caking periodically, and when replacing the filter materials during production stoppage, there are also problems such as construction period, construction safety, solid waste storage, and cost of purchasing filter materials. Another solution is to soak and dissolve with an acidic cleaning agent. Using an acidic cleaning agent results in strong corrosion of the slag water. At the same time, due to the characteristics of the slag water quality with high temperature (>80°C), high hardness (>1000mg / l), and complex water quality, the caking trend is very strong. Currently, the scale inhibition and dispersion performance of water treatment agents are not very ideal and cannot play their due role, making it difficult to solve the actual on-site problems. Therefore, there is an urgent need to develop a polymerization inhibitor suitable for treating the caking of filter materials in the bottom filter tank of blast furnace slag granulation. Summary of the Invention

[0005] In view of the above-mentioned defects, the present invention provides an inhibitor, a method of use and an application for simply, effectively and economically treating the caking of filter materials in the bottom filter tank of blast furnace slag granulation, solving the problem of caking of filter materials in the bottom filter tank of blast furnace slag granulation, prolonging the service life of filter materials, reducing the generation of solid waste, and avoiding problems such as construction period, construction safety, solid waste storage, and cost of purchasing filter materials during the process of replacing filter materials.

[0006] In the first aspect, the present invention provides an inhibitor, which, by weight, comprises: 2.0 - 10.0 parts of ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt; 1.0 - 10.0 parts of alkali metal salts of polycarboxylic acids; 2.0 - 10.0 parts of polyaspartic acid; 10.0 - 25.0 parts of caustic alkali; 2.0 - 10.0 parts of acrylic acid copolymer; 0 - 5.0 parts of synergist; and 0 - 70 parts of water; or consisting of the same.

[0007] In the second aspect, the present invention provides a method for preparing the above-mentioned inhibitor, including mixing the components of the inhibitor to provide the inhibitor in solid or aqueous solution form.

[0008] In the third aspect, the present invention provides a method of using the above-mentioned inhibitor, including:

[0009] Step 1. Provide the inhibitor in solid or aqueous solution form. When it is in solid form, dissolve it in water to form an aqueous solution, wherein, based on the total amount of solid inhibitor and water being 100 parts by weight, the amount of water used is 30 - 70 parts by weight; and

[0010] Step 2. Drain the water in the bottom filter tank, put the aqueous solution of the inhibitor in Step 1 into the bottom filter tank for soaking, and then backwash; or add the aqueous solution of the inhibitor to the slag granulation circulating water.

[0011] In the fourth aspect, the present invention provides the use of the above-mentioned inhibitor in treating the caking of filter materials in the bottom filter tank of blast furnace slag granulation.

[0012] The inventor found that the inhibitor of the present invention has emulsifying chelating effect, dispersing effect and penetrating effect, can decompose the caked mass, and destroy the chemical bonds of the existing caked mass to achieve the purpose of gradually dissolving and softening the caked mass. At the same time, with the continuous injection of the medicament, it will gradually penetrate deeper into the filter material, playing a role in gradually improving the water permeability of the bottom filter tank, making the entire slag granulation system develop in a benign manner, delaying caking, prolonging the filter material replacement cycle, saving the cost of replacing the filter material in the bottom filter tank, and increasing the service time of the bottom filter tank. The method of the present invention is simple to operate, has low treatment cost, does not pollute the environment, and does not cause damage to the equipment.

[0013] The inventors have also found that ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt have synergistic effects with other components in the polymerization inhibitor of the present invention, which can significantly enhance the dispersing effect on the plate agglomeration. In addition, the polymerization inhibitor of the present invention using ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt shows a better effect in dispersing the plate agglomeration than using other organophosphorus chelating agents, and has a significantly higher plate agglomeration decomposition rate.

[0014] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figures 1-3 The morphologies of the agglomerates AC at 0 hours after the addition of the polymerization inhibitor in Example 1 are shown in order.

[0016] Figures 4-6 The morphologies of the agglomerates AC after adding the polymerization inhibitor and soaking for 8 hours in Example 1 are shown respectively.

[0017] Figures 7-9 The morphologies of the agglomerates AC after adding the polymerization inhibitor and soaking for 24 hours in Example 1 are shown respectively.

[0018] Figures 10-12 These are the shapes of the agglomerates AC at the bottom of the beaker after adding the polymerization inhibitor and soaking for 24 hours in Example 1 and then pouring off the supernatant in the beaker. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0020] In a first aspect, the present invention provides an inhibitor comprising, by weight: 2.0-10.0 parts of ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt; 1.0-10.0 parts of alkali metal salts of polycarboxylic acids; 2.0-10.0 parts of polyaspartic acid; 10.0-25.0 parts of caustic soda; 2.0-10.0 parts of acrylic copolymers; 0-5.0 parts of synergist; and 0-70 parts of water; or consisting thereof.

[0021] In certain specific embodiments, the polymerization inhibitor comprises, by weight: 2.0-10.0 parts of ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt; 1.0-10.0 parts of alkali metal salts of polycarboxylic acids; 2.0-10.0 parts of polyaspartic acid; 10.0-25.0 parts of caustic; 2.0-10.0 parts of acrylic copolymers; and 1.0-5.0 parts of synergists; or consists thereof. In such embodiments, the polymerization inhibitor is generally present in solid form.

[0022] In certain specific embodiments, the inhibitor comprises, by weight parts: 2.0 - 10.0 parts of ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt; 1.0 - 10.0 parts of alkali metal salts of polycarboxylic acids; 2.0 - 10.0 parts of polyaspartic acid; 10.0 - 25.0 parts of caustic alkali; 2.0 - 10.0 parts of acrylic copolymers; 0 - 5.0 parts of synergist; and 30 - 70 parts of water; preferably, the total amount of the above components is 100 weight parts. In such embodiments, the inhibitor generally exists in the form of an aqueous solution.

[0023] In certain specific embodiments, the inhibitor comprises, by weight parts: 2.0 - 10.0 parts of ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt; 1.0 - 10.0 parts of alkali metal salts of polycarboxylic acids; 2.0 - 10.0 parts of polyaspartic acid; 10.0 - 25.0 parts of caustic alkali; 2.0 - 10.0 parts of acrylic copolymers; 1.0 - 5.0 parts of synergist; and 30 - 70 parts of water; or consists of the foregoing. Preferably, the total amount of the above components is 100 weight parts. In such embodiments, the inhibitor generally exists in the form of an aqueous solution.

[0024] In a preferred embodiment, the alkali metal salt of the polycarboxylic acid is an alkali metal citrate or an alkali metal tartrate.

[0025] In a preferred embodiment, the alkali metal citrate is sodium citrate, potassium citrate or a mixture thereof.

[0026] In a preferred embodiment, the alkali metal tartrate is sodium tartrate, potassium tartrate or a mixture thereof.

[0027] In a preferred embodiment, the caustic alkali is sodium hydroxide, potassium hydroxide or a mixture thereof.

[0028] In a preferred embodiment, the acrylic copolymer is a copolymer of acrylic acid and sulfonate, maleic acid - acrylic acid copolymer, acrylate - 2 - hydroxyethyl methacrylate - methyl acrylate copolymer, acrylic acid - 2 - methyl - 2 - acrylamidopropanesulfonic acid copolymer or a mixture thereof.

[0029] In a preferred embodiment, the synergist is trisodium phosphate, tripotassium phosphate or a mixture thereof.

[0030] In a preferred embodiment, the parts of ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt are 3.0 - 9.0 parts, preferably 4.0 - 8.0 parts, more preferably 5.0 - 7.0 parts, even more preferably 5.0 - 6.0 parts.

[0031] In a preferred embodiment, the amount of the alkali metal salt of the polycarboxylic acid is 2.0 - 9.0 parts, preferably 3.0 - 8.0 parts, more preferably 4.0 - 7.0 parts, and even more preferably 5.0 - 6.0 parts.

[0032] In a preferred embodiment, the amount of the polyaspartic acid is 3.0 - 9.0 parts, preferably 4.0 - 8.0 parts, more preferably 5.0 - 7.0 parts, and even more preferably 5.0 - 6.0 parts.

[0033] In a preferred embodiment, the amount of the caustic alkali is 12.0 - 22.0 parts, preferably 14.0 - 20.0 parts, and more preferably 16.0 - 18.0 parts.

[0034] In a preferred embodiment, the amount of the acrylic copolymer is 3.0 - 9.0 parts, preferably 4.0 - 8.0 parts, more preferably 5.0 - 7.0 parts, and even more preferably 5.0 - 6.0 parts.

[0035] In a preferred embodiment, the amount of the synergist is 2.0 - 4.0 parts, preferably 3.0 - 4.0 parts.

[0036] In a second aspect, the present invention provides a method for preparing the above-mentioned inhibitor, which includes mixing the components of the inhibitor to provide the inhibitor in solid or aqueous solution form.

[0037] In a third aspect, the present invention provides a method for using the above-mentioned inhibitor, including:

[0038] Step 1. Provide the inhibitor in solid or aqueous solution form. When it is in solid form, dissolve it in water to form an aqueous solution, wherein based on the total amount of the solid inhibitor and water being 100 parts by weight, the amount of water used is 30 - 70 parts by weight; and

[0039] Step 2. Drain the water in the bottom filter tank, put the inhibitor aqueous solution from Step 1 into the bottom filter tank for soaking, and then perform backwashing; or add the inhibitor aqueous solution to the slag flushing circulating water.

[0040] In certain specific embodiments, the method for using the inhibitor includes:

[0041] Step 1. Provide the inhibitor in solid form, dissolve it in water to form an aqueous solution, wherein based on the total amount of the solid inhibitor and water being 100 parts by weight, the amount of water used is 30 - 70 parts by weight; and

[0042] Step 2. Drain the water in the bottom filter tank, put the inhibitor aqueous solution from Step 1 into the bottom filter tank for soaking, and then perform backwashing.

[0043] In certain specific embodiments, the method for using the inhibitor includes:

[0044] Step 1. Provide an inhibitor in the form of an aqueous solution; and

[0045] Step 2. Drain the water in the bottom filter tank, put the inhibitor aqueous solution from Step 1 into the bottom filter tank for soaking, and then backwash.

[0046] In some specific embodiments, the usage method of the inhibitor includes:

[0047] Step 1. Provide an inhibitor in solid form, dissolve it in water to form an aqueous solution, wherein based on the total amount of the solid inhibitor and water being 100 parts by weight, the amount of water used is 30 - 70 parts by weight; and

[0048] Step 2. Add the inhibitor aqueous solution from Step 1 to the slag flushing circulating water.

[0049] In some specific embodiments, the usage method of the inhibitor includes:

[0050] Step 1. Provide an inhibitor in the form of an aqueous solution; and

[0051] Step 2. Add the inhibitor aqueous solution from Step 1 to the slag flushing circulating water.

[0052] In a preferred embodiment, Step 1 includes mixing and stirring ethylenediaminetetramethylenephosphonic acid (EDTMP) and / or its sodium salt, alkali metal salts of polycarboxylic acids, polyaspartic acid, caustic alkali, acrylic acid copolymers, water and optionally a synergist at normal temperature and pressure until an aqueous solution is formed. Preferably, stir for 30 - 120 minutes.

[0053] In a preferred embodiment, the dosage of the inhibitor aqueous solution put into the bottom filter tank is such that after adding the inhibitor aqueous solution, the liquid level height in the bottom filter tank is 5 - 50 cm, and the soaking time is 8 - 24 hours.

[0054] In a preferred embodiment, the dosing cycle of the inhibitor is 1 - 2 times per month.

[0055] In a preferred embodiment, for the step of adding the inhibitor aqueous solution to the slag flushing circulating water, the dosage of the inhibitor aqueous solution is 50 - 500 mg / L of the slag flushing circulating water.

[0056] In a fourth aspect, the present invention provides the use of the above-mentioned inhibitor in treating the clogging of the filter material in the bottom filter tank of blast furnace slag flushing. This inhibitor is applicable to treating the clogging of the filter material in the bottom filter tank of blast furnace caused by the slag flushing water quality with calcium hardness greater than 1000 mg / L and sulfate greater than 600 mg / L.

[0057] The present invention is further described in detail below through examples, but this application is not limited thereto.

[0058] Example 1

[0059] The polymerization inhibitor of this example was prepared as follows: 5 parts of ethylenediaminetetramethylenephosphonic acid sodium salt (EDTMPS) by weight; 10 parts of sodium citrate; 5 parts of polyaspartic acid; 15 parts of sodium hydroxide; 3 parts of trisodium phosphate; 2 parts of acrylic acid and sulfonate copolymer and 60 parts of water were mixed at normal temperature and pressure and stirred until an aqueous solution was formed. The acrylic acid and sulfonate copolymer was purchased from Shandong Taihe Water Treatment Technology Co., Ltd., and its trade name was acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer (AA / AMPS).

[0060] In order to verify the application effect of the polymerization inhibitor provided by the present invention on different plate agglomerates, the following tests were carried out:

[0061] 1.1 Analysis of the quality of slag flushing water:

[0062] Table 1 Analysis results of the quality of slag flushing water

[0063] Item pH value Conductivity μS / cm Chloride ion mg / L Total alkalinity mg / L Total hardness mg / L Calcium hardness mg / L Sulfate mg / L Turbidity NTU Slag tapping water A 6.86 5220 955.8 47.2 1736 1302 953 24.6 Slag tapping water B 6.47 4080 748.7 8.7 1252 1026 848.8 54.8 Slag tapping water C 7.45 7460 1168 158.6 2786 1836 2680 48.2

[0064] The total hardness, total alkalinity, and calcium hardness are all calculated as CaCO3, unit: mg / L.

[0065] 1.2 Immersion test:

[0066] 1.2.1 Test conditions:

[0067] a. Test reagent: The polymerization inhibitor prepared in Example 1;

[0068] b. Test temperature and pressure: Room temperature, normal pressure;

[0069] c. Test time: Timed in segments;

[0070] d. Test materials: The plate agglomerates in the above three different water qualities were marked as plate agglomerates A, B, and C in sequence.

[0071] 1.2.2 Test process: Pour equal amounts of the above polymerization inhibitor into 3 beakers respectively, and immerse the 3 kinds of plate agglomerates completely in the polymerization inhibitor, and observe the change of the plate agglomerates over time. The results are as Figures 1-12 shown.

[0072] From the attached Figures 1-12 results, it can be seen that each plate agglomerate after being immersed in the polymerization inhibitor of this example for 24 hours has been basically completely dispersed. The polymerization inhibitor of the present invention has an obvious dispersing effect on the plate agglomerates on site, can decompose the crystals between the plate agglomerates, crush the plate agglomerates, and gradually restore the filtering function.

[0073] Example 2

[0074] In order to investigate the synergistic effect of ethylenediaminetetramethylenephosphonic acid and / or its sodium salt with other components in the inhibitor, the following tests were conducted.

[0075] 2.1 Test conditions:

[0076] a. Test reagents: Inhibitor I is the inhibitor prepared in Example 1, Inhibitor II consists of 5 parts of EDTMPS and 95 parts of water, and Inhibitor III is the inhibitor obtained by replacing EDTMPS in the inhibitor of Example 1 with an equal amount of water;

[0077] b. Test temperature and pressure: Room temperature, atmospheric pressure;

[0078] c. Test time: Timed in segments;

[0079] d. Test materials: Plate agglomerate A in Example 1.

[0080] 2.2 Test procedure: Take 3 500-ml beakers and place about 40 g of filter material plate agglomerates in each; Pour equal amounts of the above 3 kinds of reagents into the 3 beakers respectively, so that the plate agglomerates are completely immersed in the reagents, and observe the change of the plate agglomerates over time.

[0081] After soaking for 24 hours, filter, wash, dry, and weigh the remaining plate agglomerates in the beakers.

[0082] The test results are shown in the following table:

[0083] Table 2 Test results of Example 2

[0084] Name of chemical agent Polymerization inhibitor I Polymerization inhibitor II Polymerization inhibitor III Mass of agglomerated plate before test, g 40.52 40.21 39.87 Mass of agglomerated plate after test, g 3.69 40.06 19.50 Decomposition rate of agglomerated plate, % 90.9 0.4 51.1

[0085] Test conclusion: It can be seen from the above test results that the dispersion effect of using EDTMPS alone (Inhibitor II) on the plate agglomerates is almost zero, and the decomposition rate is only 0.4%. The decomposition rate of Inhibitor III without the EDTMPS component is 51.1%. While the decomposition effect of Inhibitor I containing the EDTMPS component on the plate agglomerates is significantly improved, and the decomposition rate is as high as 90.9%.

[0086] This indicates that there is a synergistic effect between EDTMPS and other components in the inhibitor, which can significantly enhance the dispersion effect on the plate agglomerates. Therefore, when preparing the inhibitor, the reasonable combination of ethylenediaminetetramethylenephosphonic acid and / or its sodium salt with other components is crucial, which helps to improve the overall performance of the inhibitor.

[0087] Example 3

[0088] In order to investigate the decomposition effect of inhibitors using different organophosphorus chelating agents on the plate agglomerates, the following tests were conducted.

[0089] 3.1 Test conditions

[0090] a. Test reagents: The inhibitor I is the inhibitor prepared in Example 1, and the inhibitor IV is the inhibitor obtained by replacing EDTMPS in the inhibitor of Example 1 with an equal amount of hydroxyethylidene diphosphonic acid (HEDP).

[0091] b. Test temperature and pressure: Room temperature and atmospheric pressure;

[0092] c. Test time: Timed in segments;

[0093] d. Test materials: The plate agglomerate B in Example 1.

[0094] 3.2 Test procedure: Take 2 500-ml beakers and place about 35 g of filter material plate agglomerates in each; add equal amounts of the above 2 kinds of reagents to the 2 beakers respectively, so that the plate agglomerates are completely immersed in the reagents, and observe the change of the plate agglomerates over time. After soaking for 24 hours, filter, wash, dry, and weigh the remaining plate agglomerates in the beakers.

[0095] The test results are shown in the following table:

[0096] Table 3 Test results of Example 3

[0097] Name of chemical agent Polymerization inhibitor I Polymerization inhibitor IV Mass of agglomerated plate before test, g 35.72 35.75 Mass of agglomerated plate after test, g 3.58 20.57 Decomposition rate of agglomerated plate, % 90.0 42.5

[0098] Test conclusion: From the test results, the decomposition effect of inhibitor I on the plate agglomerates is significantly better than that of inhibitor IV. The mass of the plate agglomerates after being treated with inhibitor I decreased by 32.14 g, and the decomposition rate was as high as 90.0%, while the mass of the plate agglomerates after being treated with inhibitor IV only decreased by 15.18 g, and the decomposition rate was only 42.5%. This shows that inhibitor I has a stronger ability to decompose the plate agglomerates.

[0099] According to the test results, it can be concluded that inhibitor I using EDTMPS shows better results in decomposing the water slag plate agglomerates, and its decomposition rate is significantly higher than that of inhibitor IV prepared with HEDP.

[0100] Example 4

[0101] In order to investigate the synergistic effect of the synergist on the inhibitor, the following test is carried out.

[0102] 4.1 Test conditions:

[0103] a. Test reagents: The inhibitor I is the inhibitor prepared in Example 1, and the inhibitor V is the inhibitor obtained by replacing trisodium phosphate in the inhibitor of Example 1 with an equal amount of water.

[0104] b. Test temperature and pressure: Room temperature and atmospheric pressure;

[0105] c. Test time: Timed in segments;

[0106] d. Test materials: Plate agglomerate A in Example 1.

[0107] 4.2 Test procedure: Take 2 500-ml beakers and place approximately 30 g of filter material plate agglomerates in each; pour equal amounts of the above two types of agents into the two beakers respectively, so that the plate agglomerates are completely immersed in the agents, and observe the changes of the plate agglomerates over time. After 24 hours of immersion, filter, wash, dry, and weigh the remaining plate agglomerates in the beakers.

[0108] The test results are shown in the following table:

[0109] Table 4 Test results of Example 4

[0110] Name of chemical agent Polymerization inhibitor I Polymerization inhibitor V Mass of agglomerated plate before test, g 30.01 29.88 Mass of agglomerated plate after test, g 2.87 7.65 Decomposition rate of agglomerated plate, % 90.4 74.4

[0111] Test conclusion: The test results show that the decomposition rate of inhibitor I with the synergist trisodium phosphate for plate agglomerates reaches 90.4%, while the decomposition rate of inhibitor V without the synergist trisodium phosphate for plate agglomerates is 74.4%. Therefore, the synergist has a significant synergistic effect on the inhibitor. In addition, although the decomposition rate of inhibitor V for plate agglomerates is lower than that of inhibitor I for plate agglomerates, the decomposition rate of inhibitor V for plate agglomerates reaches 74.4%, and the technical effect of significantly decomposing plate agglomerates is also achieved.

[0112] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A use of an inhibitor in treating the compaction of filter material in a blast furnace slag bottom filter, characterized in that: The inhibitor comprises, by weight: 2.0-10.0 parts of ethylenediaminetetramethylenephosphonic acid and / or its sodium salt; 1.0-10.0 parts of alkali metal salt of polycarboxylic acid; 2.0-10.0 parts of polyaspartic acid; 10.0-25.0 parts of caustic soda; 2.0-10.0 parts of acrylic copolymer; 1.0-5.0 parts of synergist; and 30-70 parts of water. The synergist is trisodium phosphate, tripotassium phosphate or a mixture thereof, the acrylic copolymer is acrylic acid and sulfonate copolymer, maleic acid-acrylic acid copolymer, sodium acrylate-hydroxyethyl methacrylate-methyl acrylate copolymer, acrylic acid-2-methyl-2-acrylamidopropane sulfonic acid copolymer or a mixture thereof, the alkali metal salt of the polycarboxylic acid is alkali metal citrate or alkali metal tartaric acid, and the caustic alkali is sodium hydroxide, potassium hydroxide or a mixture thereof.

2. The use according to claim 1, characterized in that The alkali metal citrate is sodium citrate, potassium citrate or a mixture thereof, and the alkali metal tartaric acid is sodium tartrate, potassium tartrate or a mixture thereof.

3. The use according to any one of claims 1 to 2, characterized in that include: Step 1. providing the inhibitor in the form of an aqueous solution, Step 2. Drain the water in the bottom filter tank, put the inhibitor aqueous solution in step 1 into the bottom filter tank for soaking, and then backwash; or add the inhibitor aqueous solution into the slag flushing circulating water.

4. The use according to claim 3, characterized in that Step 1 comprises mixing and stirring ethylenediaminetetramethylenephosphonic acid and / or its sodium salt, alkali metal salt of polycarboxylic acid, polyaspartic acid, caustic soda, acrylic copolymer, water and synergist at normal temperature and pressure until an aqueous solution is formed.

5. The use according to claim 4, characterized in that: Stir for 30-120 minutes.

6. The use according to claim 3, characterized in that: The amount of the inhibitor aqueous solution added to the bottom filter is such that after adding the inhibitor aqueous solution, the liquid level in the bottom filter is 5-50 cm, and the soaking time is 8-24 hours; or For the step of adding the inhibitor aqueous solution into the slag flushing circulating water, the dosage of the inhibitor aqueous solution is 50-500 mg / L of the slag flushing circulating water.

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