Environment-friendly cold-pressed ball binder for vanadium extraction converter and application of environment-friendly cold-pressed ball binder

Abstract

The invention discloses an environment-friendly cold-pressed ball binder for a vanadium extraction converter and application of the environment-friendly cold-pressed ball binder, and belongs to the technical field of metallurgical auxiliary materials. The binder provided by the invention is prepared from the following raw materials in parts by mass: 60-75 parts of active magnesium oxide, 3-9 parts of hydroxymethyl cellulose, 10-21 parts of modified corn starch, 3-6 parts of dextrin, 3-7 parts of borax, 2-6 parts of polyvinyl alcohol, 3-7 parts of polyacrylamide, 2-5 parts of sodium carbonate and 4-9 parts of humic acid. The core of the invention is that the active magnesium oxide with low free silicon and low calcium oxide is used as a main component, so that the problem of free silicon dioxide dust harm generated in the production and use of the traditional clay binder is fundamentally solved. The binder is suitable for a double-roller cold pressing pelletizing process, the adding amount is 1.0-3.5 wt%, and prepared pellets are high in strength and low in pulverization rate and are environment-friendly, efficient and economical green metallurgical auxiliary materials.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical auxiliary materials technology, specifically relating to an environmentally friendly cold-pressed ball binder for vanadium extraction converters and its application. Background Technology

[0002] Currently, there are many types of raw materials used to prepare cold-pressed pellet binders. Common organic materials include various starches and cellulose polymers; common inorganic materials include bentonite and other clays. Polymers have good adhesion, but are generally expensive, and are usually added in small quantities during pelletizing. If only polymers are added, problems such as difficulty in mixing can arise. To ensure pelletizing, the amount of binder must be increased, which directly increases costs. Cold-pressed pellets are low-value products, and strict cost control is necessary to ensure reasonable profits. Clay materials are inexpensive, but have poor adhesion and are added in larger quantities. They disperse polymers while also providing adhesion. The main components of clay materials are free silica and alumina. During the production and use of binders, some dust is unavoidable. The free silica in the dust is harmful to human health, increasing the difficulty of occupational health management in the workplace. Summary of the Invention

[0003] In view of the above-mentioned prior art, the present invention provides an environmentally friendly cold-pressed ball binder for vanadium extraction converters and its application, which solves the problem of the harm of free silica to relevant personnel during the production and use of the binder.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: an environmentally friendly cold-pressed ball binder for vanadium extraction converters is provided, comprising the following raw materials in parts by weight: 60-75 parts of active magnesium oxide, 3-9 parts of hydroxymethyl cellulose, 10-21 parts of modified corn starch, 3-6 parts of dextrin, 3-7 parts of borax, 2-6 parts of polyvinyl alcohol, 3-7 parts of polyacrylamide, 2-5 parts of sodium carbonate, and 4-9 parts of humic acid.

[0005] Furthermore, the environmentally friendly cold-pressed ball binder for vanadium extraction converters comprises the following raw materials in parts by weight: 60-64 parts of active magnesium oxide, 4 parts of hydroxymethyl cellulose, 12-15 parts of modified corn starch, 3-6 parts of dextrin, 3 parts of borax, 2-4 parts of polyvinyl alcohol, 3-3.5 parts of polyacrylamide, 2-2.5 parts of sodium carbonate, and 4-5 parts of humic acid.

[0006] Furthermore, the active magnesium oxide is industrial grade, with a magnesium oxide content of over 88.0%, free silicon of less than 0.95%, calcium oxide content of less than 1.2%, average particle size of <2 micrometers, and moisture content of less than 1.5%; the hydroxymethyl cellulose has a particle size of 100 mesh with a passing rate of over 97.5%, and a viscosity (1% aqueous solution) of >2000 mPa·s. Furthermore, the modified corn starch is obtained by pregelatinizing corn starch at a temperature of 120~180℃.

[0007] Furthermore, dextrin is obtained by pregelatinizing potato starch at a temperature of 145~150℃.

[0008] Furthermore, the humic acid is water-soluble fulvic acid.

[0009] The beneficial effects of this invention are as follows: This invention uses activated magnesium oxide with extremely low free silicon content (<0.95%) as the main component and dispersion carrier, fundamentally eliminating the hazards of free silica generated by dust during the production and use of traditional clay-based binders. This significantly improves the working environment, meets occupational health standards, and effectively protects the health and safety of production personnel. Furthermore, the activated magnesium oxide has a low calcium oxide content (<1.2%), avoiding the reaction with vanadium oxides in the vanadium extraction converter to form insoluble calcium vanadate, thus ensuring a high vanadium leaching rate and not affecting vanadium recovery efficiency. This is particularly suitable for the process requirements of vanadium extraction converters. In the formulation, borax is used to enhance the mechanical properties of polymers such as polyvinyl alcohol and polyacrylamide; sodium carbonate can adjust the pH value of the pellets, promote starch modification and cross-linking, and enhance pellet toughness; modified corn starch and dextrin act as later-stage strength enhancers, jointly constructing a stable and high-strength microstructure for the pellets. Moreover, this invention uses low-cost active magnesium oxide as the main component and combines it with a variety of polymer materials. While ensuring excellent bonding performance, it effectively controls costs. Its preparation method is simple, requiring only the mixing of each raw material in the specified ratio. It does not require complex processes and is easy to industrialize.

[0010] This invention also provides the application of an environmentally friendly cold-pressed ball binder for vanadium extraction converters in the cold pressing of balls by rollers.

[0011] Furthermore, the amount of environmentally friendly vanadium extraction converter cold-pressed ball binder added in the double-roll cold-pressing balling process is 1~3.5wt%.

[0012] The beneficial effects of this invention are as follows: The binder provided by this invention requires a small amount (1.0~3.5wt%) in the cold-pressing pelletizing process, has a wide range of applications, and exhibits good pelletizing effects on various secondary resources in steel enterprises (such as iron oxide scale, dust, sludge, etc.). Through the synergistic effect between its components, it endows cold-pressed pellets with excellent mechanical properties. The strength of green pellets can reach 150~190N, and the strength of dried pellets (moisture content ≤3%) can reach 600~900N. Moreover, the pulverization rate during loading, unloading, and transportation is low (≤5%), meeting the strength requirements of industrial transportation and smelting. Detailed Implementation

[0013] The specific embodiments of the present invention will be described in detail below with reference to examples.

[0014] Example 1 An environmentally friendly cold-pressed ball binder for vanadium extraction converters comprises the following raw materials in parts by weight: 60 parts activated magnesium oxide, 4 parts hydroxymethyl cellulose, 12 parts modified corn starch, 6 parts dextrin, 3 parts borax, 4 parts polyvinyl alcohol, 3.5 parts polyacrylamide, 2.5 parts sodium carbonate, and 5 parts water-soluble humic acid; wherein the modified corn starch is obtained by pregelatinizing corn starch at 150°C, and the 80-mesh passing rate is greater than 90%; the dextrin is obtained by pregelatinizing potato starch at 150°C, and the 100-mesh passing rate is greater than 95%.

[0015] In this embodiment, the environmentally friendly vanadium extraction converter cold-pressing briquetting agent is used to briquette secondary resources using a double-roll cold pressing process. The composition of each secondary resource by mass percentage is as follows: 35% iron oxide scale from rebar, 27% iron oxide scale from hot-rolled steel plate, 22% dust from steelmaking converters, 10% dust from ironmaking blast furnaces, 6% dust from raw material silos, and 1% additional environmentally friendly vanadium extraction converter cold-pressing briquetting agent. The main process parameters for briquetting are as follows: after mixing the secondary resources in the specified proportions, the mixture is allowed to rest for 48 hours before briquetting; the mixing time in the mixer is 240 seconds; the briquetting size is 40mm × 55mm; and the briquetting machine pressure is 5MPa.

[0016] Example 2 An environmentally friendly cold-pressed ball binder for vanadium extraction converters comprises the following raw materials in parts by weight: 64 parts activated magnesium oxide, 4 parts hydroxymethyl cellulose, 15 parts modified corn starch, 3 parts dextrin, 3 parts borax, 2 parts polyvinyl alcohol, 3 parts polyacrylamide, 2 parts sodium carbonate, and 4 parts water-soluble humic acid; wherein the modified corn starch is obtained by pregelatinizing corn starch at 150°C, and the 80-mesh passing rate is greater than 90%; the dextrin is obtained by pregelatinizing potato starch at 150°C, and the 100-mesh passing rate is greater than 95%.

[0017] In this embodiment, the environmentally friendly vanadium extraction converter cold-pressing briquetting binder is used to briquette secondary resources using a double-roll cold pressing process. The composition of each secondary resource by mass percentage is as follows: 30% rebar iron oxide scale, 30% hot-rolled plate iron oxide scale, 20% steelmaking converter dust, 14% ironmaking blast furnace dust, 6% raw material silo dust, and 3.5% environmentally friendly vanadium extraction converter cold-pressing briquetting binder. The main process parameters for briquetting are as follows: after mixing the secondary resources in the specified proportions, the mixture is allowed to rest for 28 hours before briquetting; the mixing time in the mixer is 240 seconds; the briquetting size is 40mm × 55mm; and the briquetting machine pressure is 6MPa.

[0018] Comparative Example A cold-pressed ball binder for vanadium extraction converters comprises the following raw materials in parts by weight: 60 parts magnesium oxide, 4 parts hydroxymethyl cellulose, 12 parts modified corn starch, 6 parts dextrin, 3 parts borax, 4 parts polyvinyl alcohol, 3.5 parts polyacrylamide, 2.5 parts sodium carbonate, and 5 parts water-soluble humic acid; wherein the modified corn starch is obtained by pregelatinizing corn starch at 150°C, and the 80-mesh passing rate is greater than 90%; the dextrin is obtained by pregelatinizing potato starch at 150°C, and the 100-mesh passing rate is greater than 95%.

[0019] In this comparative example, the vanadium extraction converter cold-pressing briquetting process uses a binder for secondary resources to form briquettes. The percentage composition of each secondary resource is as follows: 35% iron oxide scale from rebar, 27% iron oxide scale from hot-rolled steel plates, 22% dust from steelmaking converters, 10% dust from blast furnaces, 6% dust from raw material silos, and an additional 1% of environmentally friendly vanadium extraction converter cold-pressing briquetting binder. The main process parameters for briquetting are as follows: after mixing the secondary resources in the specified proportions, the mixture is allowed to rest for 48 hours before briquetting; the mixing time in the mixer is 240 seconds; the briquetting size is 40mm × 55mm; and the briquetting machine pressure is 5MPa.

[0020] Experimental Example The pellets obtained in Examples 1-2 and the comparative example were tested for strength and pulverization rate. The test results are shown in Table 1. The environmentally friendly cold-pressed pellet binder for vanadium extraction converters in the present invention endows the cold-pressed pellets with excellent mechanical properties through the synergistic effect between the components. The green pellet strength can reach 150-190N, and the pellet strength after drying (moisture ≤3%) is as high as 600-900N. Moreover, the pulverization rate during loading, unloading and transportation is low (≤5%), which undoubtedly meets the strength requirements of industrial transportation and smelting and has excellent industrial application value. Although the pellets in the comparative example still have excellent mechanical properties, their pulverization rate is much higher than that of the examples. This is because the magnesium oxide used in the comparative example has not been activated, and has more impurities, smaller specific surface area and lower chemical activity than activated magnesium oxide, and cannot effectively adsorb free silica.

[0021] Table 1. Statistics on the strength and pulverization rate of pellets

[0022] Although specific embodiments of the present invention have been described in detail with reference to examples, they should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims are still within the scope of protection of this patent.

Claims

1. An environment-friendly cold-pressed ball binder for a vanadium extraction converter, characterized in that, The raw materials include the following mass fractions: active magnesium oxide 60-75 parts, hydroxymethyl cellulose 3-9 parts, modified corn starch 10-21 parts, dextrin 3-6 parts, borax 3-7 parts, polyvinyl alcohol 2-6 parts, polyacrylamide 3-7 parts, sodium carbonate 2-5 parts, and humic acid 4-9 parts.

2. The cold-pressed ball binder for the environment-friendly vanadium extraction converter according to claim 1, characterized in that, The raw materials include the following mass fractions: active magnesium oxide 60-64 parts, hydroxymethyl cellulose 4 parts, modified corn starch 12-15 parts, dextrin 3-6 parts, borax 3 parts, polyvinyl alcohol 2-4 parts, polyacrylamide 3-3.5 parts, sodium carbonate 2-2.5 parts, and humic acid 4-5 parts.

3. The environment-friendly cold-pressed ball binder for vanadium extraction converter according to any one of claims 1-2, characterized in that: The modified corn starch is obtained by pre-gelatinization of corn starch at a temperature of 120-180℃.

4. The environment-friendly cold-pressed ball binder for vanadium extraction converter according to any one of claims 1-2, characterized in that: The dextrin is obtained by pre-gelatinization of potato starch at a temperature of 145-150℃.

5. The environment-friendly cold-pressed ball binder for vanadium extraction converter according to any one of claims 1-2, characterized in that: The humic acid is water-soluble fulvic acid.

6. Application of the environment-friendly cold-pressing ball binder for vanadium extraction converter in cold-pressing into balls.

7. Use according to claim 6, characterized in that: The addition amount of the environment-friendly cold-pressing ball binder for vanadium extraction converter in the cold-pressing into balls process is 1-3.5 wt%.

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