WO2021197258A1 - Oxidized pellet binding agent made from low-rank coal, preparation method for same, and applications thereof - Google Patents

Oxidized pellet binding agent made from low-rank coal, preparation method for same, and applications thereof Download PDF

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Publication number
WO2021197258A1
WO2021197258A1 PCT/CN2021/083574 CN2021083574W WO2021197258A1 WO 2021197258 A1 WO2021197258 A1 WO 2021197258A1 CN 2021083574 W CN2021083574 W CN 2021083574W WO 2021197258 A1 WO2021197258 A1 WO 2021197258A1
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low
oxidized
rank coal
iron ore
pellets
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PCT/CN2021/083574
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French (fr)
Chinese (zh)
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李光辉
罗骏
姜涛
张鑫
饶明军
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中南大学
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Publication of WO2021197258A1 publication Critical patent/WO2021197258A1/en

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
    • C22B1/24—Binding; Briquetting ; Granulating
    • C22B1/242—Binding; Briquetting ; Granulating with binders

Definitions

  • the invention relates to an oxidized pellet binder made from low-rank coal, a preparation method and application thereof, and belongs to the technical field of iron and steel metallurgy.
  • the main iron-containing raw materials for steel production include sinter, pellets and lump ore.
  • the lump ore resources that meet the requirements of iron smelting production are almost exhausted, and most of the iron ore fines or iron concentrates need to be agglomerated (sintered or pelletized) to meet the production requirements.
  • steel production is mainly based on the long process of blast furnace-converter, which uses sinter, pellets and coke as raw materials to obtain molten iron after blast furnace ironmaking, and then uses blast furnace molten iron as raw material to enter the converter steelmaking.
  • the long-process production of iron and steel usually uses high-basicity sinter with acidic oxide pellets as the charge. Compared with sinter, pellets have the advantages of high iron grade, good strength, uniform particle size, and good reducibility.
  • the production energy consumption of pelletizing process is low.
  • the energy consumption of pelletizing process of advanced enterprises is only 1/of the energy consumption of sintering process. About 3; less pollutant emissions, less harmful components in the exhaust gas, and low cost of subsequent end treatment.
  • the pollutant emissions of the pelletizing process are much lower than that of the sintering process.
  • the emissions of dust, sulfur dioxide, and nitrogen oxides are respectively 1/of the sintering process. 7, 1/3, 1/5.
  • the binder In the production process of iron concentrate pellets, the binder has an important influence on the pellet preparation process and the quality of the pellets.
  • the production of pellets in my country has problems such as large amount of binder and low iron grade.
  • Iron and steel plants in my country generally use bentonite as a binder to prepare oxidizing pellets.
  • the quality of bentonite in my country is poor, and the iron ore concentrate used for pellet production has a relatively high coarse-grained content.
  • a higher proportion of bentonite must be added to meet the requirements of industrial production. Because the addition of bentonite brings in a large amount of impurities such as aluminosilicate, it seriously reduces the iron grade of the pellets, and significantly increases the energy consumption and production costs of ironmaking.
  • the purpose of the invention is to provide a method for preparing an oxidized pellet binder made from low-rank coal, which uses low-rank coal as a raw material to obtain oxidized pellets through simple oxidative fermentation, and then simultaneous extraction and slurrying of humic acid.
  • Group binder cheap raw materials, wide sources, simple process, low binder content, good bonding performance, strong applicability, not only can significantly improve the spheroidizing performance of difficult-to-form nodular iron ore resources, but also for the iron of the finished ball Taste does not affect.
  • the present invention adopts the following technical solutions.
  • a method for producing oxidized pellet binder from low-rank coal The low-rank coal is crushed and oxidized and fermented, then solid caustic alkali and water are added to prepare a slurry, and the oxidized pellet binder is obtained by heating and stirring.
  • the humic acid content in the low-rank coal is not less than 25%; more preferably, the humic acid content in the low-rank coal is not less than 30%; after crushing, the particle size is less than 10 mm.
  • the temperature of the oxidative fermentation is 80 to 200° C., and the time is 2 to 10 hours, and after the oxidative fermentation is completed, low-rank coal is further ground to a particle size of less than 0.1 mm and a particle content of more than 70%.
  • the added amount of the solid caustic soda occupies 20%-30% of the mass of the low-rank coal; the added amount of water is 2-5 times the mass of the low-rank coal.
  • the temperature of the heating and stirring is 50 ⁇ 100°C, and the time is 1 ⁇ 5h.
  • the invention also provides the oxidized pellet binder prepared by the above preparation method, which has a high content of organic components, good bonding performance and strong applicability.
  • the present invention also provides the application of the above-mentioned oxidized pellet binder, which is added to iron ore powder for pelletizing to obtain green iron ore pellets for oxidized pellets.
  • the oxidized pellet binder of the present invention can be used for hard-to-ballite and inferior iron ore resources with poor ball-forming properties, such as vanadium-titanium magnetite, maghemite, etc., and can enhance the surface hydrophilicity of the hard-to-ballite inferior iron ore It is beneficial to the iron ore particles to form balls.
  • poor ball-forming properties such as vanadium-titanium magnetite, maghemite, etc.
  • the iron ore powder is subjected to wet grinding or high-pressure roller milling before pelletizing, which can further improve the green pellet strength.
  • the additive amount of the oxidized pellet binder accounts for 1% to 4% of the mass of the iron ore powder, and the amount of humic acid in the oxidized pellet binder accounts for 0.2% to 0.5% of the mass of the iron ore powder.
  • the prepared green iron ore pellets are oxidized and preheated and roasted at 900-1050°C for 4-12 minutes and then used for the production of oxidized pellets or direct reduced iron.
  • Humic acid contains carboxyl, hydroxyl and benzene ring structures, and has a binder molecular structure.
  • Low-rank coal is the main source of extraction of humic acid, but the content of humic acid varies greatly.
  • Existing extraction methods generally include extraction, evaporation, drying, grinding and other processes, which have high energy consumption, long process, and low extraction rate.
  • the prepared humic acid product is in a solid state. When used in the production of oxidized pellets, it is difficult to disperse and its binding effect is limited.
  • low-rank coal undergoes pre-oxidation and fermentation to increase the content of humic acid by 1.2 to 2 times, and then humic acid is extracted simultaneously and the slurry is adjusted to obtain the oxidized pellet binder, which is directly mixed with iron ore powder to prepare green pellets.
  • the dissolved humic acid forms a colloidal solution, which can evenly cover the surface of iron ore particles, significantly improve the surface hydrophilicity of iron ore particles, and increase the surface tension of iron ore; and through the long-chain structure of the binder on the surface of iron ore particles
  • the bridge function connects the iron ore particles, which is beneficial to the iron ore particles to form balls and improve the green ball strength.
  • the adhesive prepared by the invention has good bonding performance, can improve the spheroidizing performance of iron ore, has strong product adaptability, can be suitable for inferior iron ore pellets that are difficult to pelletize, and significantly improves the green spheroidizing strength.
  • Bentonite is used as the binder. Most of the bentonite is an inorganic component. After the green ball is roasted, the bentonite will remain in the finished ball, reducing the iron grade in the finished ball. According to blast furnace production practice, for every 1% increase in the iron grade of the finished ball into the furnace, the blast furnace coke ratio will decrease by 2%, the ironmaking output will increase by 3%, and the blast furnace slag will be reduced by 20kg/t. Therefore, the use of bentonite binder will greatly improve ironmaking Production costs reduce production efficiency.
  • the binder prepared by the present invention is an organic binder with a high content of organic components.
  • the organic components will all burn and volatilize during the preheating and roasting process of the oxidized pellets, which will not affect the iron grade of the finished pellets. Compared with bentonite pellets, the iron grade is improved, and the corresponding ironmaking output is significantly increased and the production cost is significantly reduced.
  • low-rank coal is oxidized and fermented to significantly increase the humic acid content in the coal, and then the humic acid is extracted simultaneously and the slurry is adjusted to obtain the oxidized pellet binder, which is directly mixed with iron ore powder to prepare green pellets.
  • the effective components of humic acid are high, and there is no need to use humic acid in conjunction with other binders; there is no need to prepare the extracted humic acid components into powder products, and the process steps such as slurry drying, crushing and grinding are omitted, and the process is short, Low energy consumption and high process efficiency.
  • low-rank lignite is selected as the raw material, and its humic acid content is 32 wt%.
  • the lignite is crushed to below 10mm, fully oxidized and fermented at 120°C for 6h, and further ground to a particle size of less than 0.1mm.
  • the particle mass accounts for 85% of the total mass of pulverized coal; solid caustic which accounts for 25% of its mass is added to the pulverized coal.
  • Alkali and 400% water are used to prepare coal slurry.
  • the coal slurry is heated to a temperature of 95°C and continuously stirred for 3 hours to obtain an oxidized pellet binder.
  • vanadium-titanium magnetite which is difficult to pelletize, is selected as the iron ore raw material.
  • the main components of vanadium-titanium magnetite are shown in Table 1, and pellets are made by adding the prepared binder.
  • vanadium-titanium magnetite as raw material for pelletizing, the raw material moisture is 5.0wt%, and 3.0wt% of the binder is added to the vanadium-titanium magnetite powder to keep the moisture at 8.0wt% during pelletizing. Mix thoroughly and evenly, then sieve the mixture to less than 1mm, and use a disc pelletizer to pelletize the pellets. The pelletizing time is 10 ⁇ 12min and the pellet size is 10 ⁇ 12mm.
  • the obtained iron ore green balls were tested, the green balls falling strength was 3.5 times/(0.5m), and the compressive strength was 13.7N/piece.
  • Pellets are pelletized from vanadium-titanium magnetite with a raw material moisture of 5.0wt%, and 3.0wt% of its mass is added to the vanadium-titanium magnetite powder to keep the moisture at 8.0wt% during pelletizing.
  • the obtained iron ore green balls were tested, the green balls falling strength was 2.3 times/(0.5m), and the compressive strength was 11.7N/piece.
  • Pellets are pelletized from vanadium-titanium magnetite with a raw material moisture of 5.0wt%, and 3.0wt% of its mass is added to the vanadium-titanium magnetite powder to keep the moisture at 8.0wt% during pelletizing.
  • the pelletizing time is 10 ⁇ 12min, and the pellet size 10 ⁇ 12mm.
  • the obtained iron ore green balls were tested, the green balls falling strength was 3.3 times/(0.5m), and the compressive strength was 13.2N/piece.
  • Example 1 Comparing the green ball index data in Example 1 and Comparative Example 1-2, in Comparative Example 1-2, in order to meet the minimum requirement of iron ore green ball falling strength higher than 3.0 times/(0.5m), the bentonite binder is the lowest The dosage needs to reach more than 1.5%.
  • Example 1 when the present invention adds 3.0wt% of binder prepared from low-rank lignite (that is, the humic acid composition distribution is 0.45wt%), the green ball drop strength and compressive strength are both higher than that of bentonite Green ball strength when the amount of binder is 1.5wt%. It shows that the binder prepared by the present invention has good bonding performance and a small amount, and can improve the ball-forming performance of the hard-to-form ductile iron ore.
  • the vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized.
  • the iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets.
  • the pelletizing time is 10-12min and the pellet size is 10-12mm.
  • the obtained iron ore green balls were tested, the green balls falling strength was 8.6 times/(0.5m), and the compressive strength was 21.3N/piece.
  • the vanadium-titanium magnetite is pelletized after being pretreated by a high-pressure roller mill for 3 times, and 3.0wt% of its mass is added to the iron ore powder to keep the moisture at 8.0wt% during pelletization, and then added
  • the bentonite binder which accounts for 1.5wt% of the iron ore powder mass, is fully mixed and evenly mixed, and then the material is sieved to below 1mm, and pelletized by a disc pelletizer.
  • the pelletizing time is 10 ⁇ 12min, and the pellet size is 10 ⁇ 12mm.
  • the obtained iron ore green balls were tested, the green balls falling strength was 5.7 times/(0.5m), and the compressive strength was 18.4N/piece.
  • the iron grade of the finished oxidized pellets produced by the binder prepared by the present invention is 54.65%, which is higher than the iron grade of the finished oxidized pellets produced by the bentonite binder 1%.
  • the iron grade of the finished ball into the furnace is increased by 1%, the blast furnace coke ratio is reduced by 2%, the iron production is increased by 3%, and the blast furnace slag volume is reduced by 20 kg/t. Therefore, the binder prepared by the invention can greatly reduce the refining rate. Iron production costs.
  • humic acid content is 32wt%. Grind it to a particle size of less than 0.1mm. The particle mass accounts for 85% of the total mass of pulverized coal; add 25% of the mass of solid caustic soda and 400% of water to the pulverized coal to prepare a coal slurry, and heat the coal slurry to a temperature of 95 °C and continue to stir for 3h to obtain the oxidized pellet binder.
  • the vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized. The iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing.
  • the obtained iron ore green balls were tested, the green balls falling strength was 2.1 times/(0.5m), the compressive strength was 8.3N/piece, and the burst temperature was 510°C.
  • an oxidized pellet binder was obtained.
  • the vanadium-titanium magnetite is pelletized after being pretreated by a high-pressure roller mill for 3 times, and a binder slurry of 4.0wt% of its mass is added to the iron ore powder to keep the water content at 8.0wt% during pelletizing. Mix evenly, then sieve the material to below 1mm, and use a disc pelletizer to pelletize the pellets.
  • the pelletizing time is 10 ⁇ 12min and the pellet size is 10 ⁇ 12mm.
  • the obtained iron ore green balls were tested and found that the falling strength of the green balls was 2.8 times/(0.5m), the compressive strength was 9.6N/piece, and the burst temperature was 460°C.
  • Example 3 Low-rank lignite was fully oxidized and fermented at a temperature of 120°C for 6 hours, and then ground to a particle size of less than 0.1 mm. The particle mass accounted for 85% of the total mass of pulverized coal; solid caustic alkali accounting for 20% of its mass was added to the pulverized coal Prepare a coal slurry with 400% water. The coal slurry is heated to a temperature of 80°C and continuously stirred for 3 hours to obtain an oxidized pellet binder. The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized.
  • the iron ore powder is mixed with 1.0wt% of its mass and 2.0wt% of binder slurry to make the water during pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10-12min and the pellet size is 10-12mm.
  • the obtained iron ore green balls were tested and found that the falling strength of the green balls was 7.3 times/(0.5m), the compressive strength was 20.6N/piece, and the burst temperature was 550°C.
  • Example 3 Using the fermented coal powder obtained in Example 3 as raw materials, adding 30% of the mass of solid caustic soda and 400% of water to prepare a coal slurry, the coal slurry is heated to a temperature of 80°C and continuously stirred for 3 hours to obtain oxidized pellets Group binder.
  • the vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized.
  • the iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets.
  • the pelletizing time is 10-12min and the pellet size is 10-12mm.
  • the obtained iron ore green balls were tested and found that the falling strength of the green balls was 9.6 times/(0.5m), the compressive strength was 22.1N/piece, and the burst temperature was 530°C.
  • Example 3 Using the fermented coal powder obtained in Example 3 as raw materials, adding 15% of its mass of solid caustic soda and 400% of water to prepare a coal slurry, heat the coal slurry to a temperature of 80°C and continue stirring for 3 hours to obtain oxidized pellets Group binder.
  • the vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized.
  • the iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets.
  • the pelletizing time is 10-12min and the pellet size is 10-12mm.
  • the obtained iron ore green balls were tested, and the green balls had a falling strength of 2.8 times/(0.5m), a compressive strength of 12.8N/piece, and a burst temperature of 480°C.
  • Example 3 Using the fermented coal powder obtained in Example 3 as raw materials, adding 35% of the mass of solid caustic soda and 400% water to prepare a coal slurry.
  • the coal slurry is heated to a temperature of 80°C and continuously stirred for 3 hours to obtain oxidized pellets.
  • Group binder The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized.
  • the iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets.
  • the pelletizing time is 10-12min and the pellet size is 10-12mm.
  • the obtained iron ore green balls were tested, and the green balls had a falling strength of 3.2 times/(0.5m), a compressive strength of 13.2N/piece, and a burst temperature of 390°C.
  • Example 3-4 Comparing the green ball index data in Example 3-4 and Comparative Example 6-7, when the dosage of solid caustic alkali is outside the preferred range, the prepared binder slurry cannot satisfy the iron ore green ball falling strength at the same time.
  • the minimum requirement is higher than 3.0 times/(0.5m) and burst temperature higher than 450°C.
  • a coal slurry is prepared by adding 20% of the mass of solid caustic soda and 200% of the coal powder to the coal powder.
  • the coal slurry is heated to a temperature of 60°C and continuously stirred for 5 hours to obtain an oxidized pellet binder slurry.
  • the binder is used to pelletize the magnetite concentrate.
  • the binder content is 1%, and the pellets are pelletized after high-pressure roller milling.
  • the pelletizing time is 10-12 minutes, and the green pellet size is 14-16mm.
  • the green ball has a drop strength of 8.1 times/(0.5m), a compressive strength of 27.8N, and a burst temperature of 570°C, which all meet the requirements of pellet production.
  • the oxidized pellet binder slurry prepared in Example 5 Take the oxidized pellet binder slurry prepared in Example 5 and use it to pelletize hematite concentrate.
  • the binder content is 1.5%.
  • the pellets are pelletized after high-pressure roller milling.
  • the pelletizing time is 10-12 minutes.
  • the ball size is 14 ⁇ 16mm.
  • the drop strength of the green ball is 9.2 times/(0.5m), the compressive strength is 25.2N, and the burst temperature is 520°C, which all meet the requirements of pellet production.
  • the prepared qualified green balls are oxidized and preheated and roasted at a preheating temperature of 1000°C, a preheating time of 4 minutes, and a compressive strength of 1050N/piece.
  • the oxidized preheated pellets are used for direct reduced iron production.
  • the oxidized pellet binder slurry prepared in Example 5 was used to pelletize ordinary iron fine powder, the binder content was 1.0%, the pelletizing time was 10-12 minutes, and the green pellet size was 14-16mm.
  • the green ball has a drop strength of 8.7 times/(0.5m), a compressive strength of 23.2N, and a burst temperature of 580°C, which all meet the requirements of pellet production.
  • the prepared qualified green pellets are oxidized and preheated and roasted at a preheating temperature of 900°C, a preheating time of 5 minutes, and a compressive strength of 970N/piece.
  • the oxidized preheated pellets are used for the production of direct reduced iron.

Abstract

Disclosed are an oxidized pellet binding agent made from a low-rank coal, a preparation method for same, and applications thereof. The low-rank coal is crushed and then oxidized and fermented, then, solid caustic soda and water are added to modulate the slurry, which is heated and stirred to produce the oxidized pellet binding agent. The amount of the solid caustic soda added accounts for 20% to 30% of the mass of the low-rank coal; the amount of water added is 2 to 5 times of the mass of the low-rank coal. The oxidized pellet binding agent is added into iron ore powder for pelletizing to produce iron ore raw pellets for use as oxidized pellets. The present invention adopts the low-rank coal as a raw material and produces the oxidized pellet biding agent by means of simple oxidization and fermentation followed by the simultaneous performance of humic acid extraction and slurry modulation. The raw material is inexpensive and readily available and has a simple process. The binding agent allows reduced usage, provides great binding performance, and has strong applicability, not only improves the pelletizing performance of a difficult-to-pelletize iron ore resource, but also does not affect the iron product grade of product pellets.

Description

一种由低阶煤制造的氧化球团粘结剂及其制备方法和应用Oxidized pellet binder made from low-rank coal, and preparation method and application thereof 技术领域Technical field
本发明涉及一种由低阶煤制造的氧化球团粘结剂及其制备方法和应用，属于钢铁冶金技术领域。The invention relates to an oxidized pellet binder made from low-rank coal, a preparation method and application thereof, and belongs to the technical field of iron and steel metallurgy.
背景技术Background technique
钢铁是国民经济建设和社会发展的重要基础材料，自2000年以来，中国粗钢产量迅速增长，2000年我国粗钢产量为1.27亿吨，仅占全球粗钢总产量的15%。2018年中国粗钢累计产量达到9.28亿吨，占世界钢铁产量的一半以上。Steel is an important basic material for national economic construction and social development. Since 2000, China's crude steel output has grown rapidly. In 2000, my country's crude steel output was 127 million tons, only 15% of the world's total crude steel output. In 2018, China's cumulative crude steel output reached 928 million tons, accounting for more than half of the world's steel output.
随着钢铁产量的不断增长，其生产的炉料结构也处于不断发展之中。钢铁生产的主要含铁原料包括烧结矿、球团矿和块矿。随着优质铁矿资源的日益短缺，满足炼铁生产要求的块矿资源几乎消耗殆尽，绝大部分铁矿粉或铁精矿需要进行造块（烧结或者球团）才能满足生产要求。当前钢铁生产以高炉-转炉长流程为主，以烧结矿、球团矿和焦炭等为原料经高炉炼铁后获得铁水，再以高炉铁水为原料进入转炉炼钢。With the continuous growth of steel output, the charge structure of its production is also under continuous development. The main iron-containing raw materials for steel production include sinter, pellets and lump ore. With the increasing shortage of high-quality iron ore resources, the lump ore resources that meet the requirements of iron smelting production are almost exhausted, and most of the iron ore fines or iron concentrates need to be agglomerated (sintered or pelletized) to meet the production requirements. At present, steel production is mainly based on the long process of blast furnace-converter, which uses sinter, pellets and coke as raw materials to obtain molten iron after blast furnace ironmaking, and then uses blast furnace molten iron as raw material to enter the converter steelmaking.
钢铁长流程生产通常采用高碱度烧结矿配加酸性氧化球团矿作为炉料。与烧结矿相比，球团矿具有铁品位高、强度好、粒度均匀、还原性好等优点，球团工序生产能耗低，先进企业球团工序能耗仅为烧结工序能耗的1/3左右；污染物排放量少，废气中有害成分少，后续的末端治理成本低，球团工序的污染物排放远低于烧结工序，粉尘、二氧化硫、氮氧化物排放分别是烧结工序的1/7、1/3、1/5。在国外部分高炉生产中球团矿比例达到70%以上，甚至达到100%。2018年国内球团矿产量约为1.59亿吨，进口量为1850万吨，球团矿产量未能满足钢铁生产要求，球团矿入炉配比仅为14%，远低于世界平均水平。The long-process production of iron and steel usually uses high-basicity sinter with acidic oxide pellets as the charge. Compared with sinter, pellets have the advantages of high iron grade, good strength, uniform particle size, and good reducibility. The production energy consumption of pelletizing process is low. The energy consumption of pelletizing process of advanced enterprises is only 1/of the energy consumption of sintering process. About 3; less pollutant emissions, less harmful components in the exhaust gas, and low cost of subsequent end treatment. The pollutant emissions of the pelletizing process are much lower than that of the sintering process. The emissions of dust, sulfur dioxide, and nitrogen oxides are respectively 1/of the sintering process. 7, 1/3, 1/5. The proportion of pellets in the production of some blast furnaces abroad has reached more than 70%, or even 100%. In 2018, the domestic production of pellets was approximately 159 million tons, and the import volume was 18.5 million tons. The output of pellets failed to meet the requirements of steel production, and the ratio of pellets into the furnace was only 14%, far below the world average.
在铁精矿球团生产过程中，粘结剂对球团制备过程及球团矿质量产生重要影响。我国球团矿生产存在着粘结剂用量大、铁品位低等问题。我国钢铁厂普遍采用膨润土作为粘结剂制备氧化性球团矿。但是我国膨润土质量较差，且用于球团矿生产的铁精矿粗粒级含量较高，需配加较高比例的膨润土才能满足工业生产的要求。由于膨润土的加入带进大量的铝硅酸盐等杂质，严重降低球团矿铁品位，显著增加炼铁能耗和生产成本。In the production process of iron concentrate pellets, the binder has an important influence on the pellet preparation process and the quality of the pellets. The production of pellets in my country has problems such as large amount of binder and low iron grade. Iron and steel plants in my country generally use bentonite as a binder to prepare oxidizing pellets. However, the quality of bentonite in my country is poor, and the iron ore concentrate used for pellet production has a relatively high coarse-grained content. A higher proportion of bentonite must be added to meet the requirements of industrial production. Because the addition of bentonite brings in a large amount of impurities such as aluminosilicate, it seriously reduces the iron grade of the pellets, and significantly increases the energy consumption and production costs of ironmaking.
此外，随着优质铁矿资源日益枯竭，越来越多的难造球劣质铁矿资源用于球团矿的生产，如钒钛磁铁矿、镜铁矿、磁赤混合矿、含铁粉尘等。为改善劣质铁矿资源的成球性能或者焙烧性能，需要配加更高比例的膨润土来满足生产要求，但是部分劣质含铁资源采用膨润土无法制备球团。In addition, with the depletion of high-quality iron ore resources, more and more difficult-to-ball inferior iron ore resources are used for the production of pellets, such as vanadium-titanium magnetite, specularite, maghemite, and iron-containing dust Wait. In order to improve the pelletizing performance or roasting performance of inferior iron ore resources, a higher proportion of bentonite needs to be added to meet the production requirements, but some inferior iron-containing resources cannot be used to prepare pellets using bentonite.
技术问题technical problem
针对现有铁矿球团生产过程中膨润土添加导致的球团矿脉石含量增加、铁品位下降、钢铁生产能耗升高以及部分劣质铁矿资源无法使用膨润土粘结剂进行造球的问题，本发明的目的是在于提供一种由低阶煤制造的氧化球团粘结剂的制备方法，以低阶煤为原料，通过简单的氧化发酵，然后同步进行提取腐植酸与调浆即得氧化球团粘结剂，原料廉价来源广、工艺简单，其粘结剂用量低、粘结性能好、适用性强，不仅能够明显改善难造球铁矿资源的成球性能，而且对成品球的铁品位不产生影响。In view of the increase in pellet gangue content caused by the addition of bentonite in the production process of the existing iron ore pellets, the decline in iron grade, the increase in energy consumption in steel production, and the inability of some inferior iron ore resources to be pelletized with bentonite binders, this The purpose of the invention is to provide a method for preparing an oxidized pellet binder made from low-rank coal, which uses low-rank coal as a raw material to obtain oxidized pellets through simple oxidative fermentation, and then simultaneous extraction and slurrying of humic acid. Group binder, cheap raw materials, wide sources, simple process, low binder content, good bonding performance, strong applicability, not only can significantly improve the spheroidizing performance of difficult-to-form nodular iron ore resources, but also for the iron of the finished ball Taste does not affect.
技术解决方案Technical solutions
为了实现上述技术目的，本发明采用如下技术方案。In order to achieve the above technical objectives, the present invention adopts the following technical solutions.
一种由低阶煤制造氧化球团粘结剂的方法，将低阶煤破碎后进行氧化发酵，再加入固体苛碱和水调制浆液，经加热搅拌即得氧化球团粘结剂。A method for producing oxidized pellet binder from low-rank coal. The low-rank coal is crushed and oxidized and fermented, then solid caustic alkali and water are added to prepare a slurry, and the oxidized pellet binder is obtained by heating and stirring.
优选的，所述低阶煤中的腐植酸含量不低于25%；进一步优选为低阶煤中的腐植酸含量不低于30%；经破碎至粒度小于10mm。Preferably, the humic acid content in the low-rank coal is not less than 25%; more preferably, the humic acid content in the low-rank coal is not less than 30%; after crushing, the particle size is less than 10 mm.
优选的，所述氧化发酵的温度为80~200℃，时间为2~10h，且氧化发酵完成后进一步将低阶煤磨至粒度小于0.1mm颗粒含量达到70%以上。Preferably, the temperature of the oxidative fermentation is 80 to 200° C., and the time is 2 to 10 hours, and after the oxidative fermentation is completed, low-rank coal is further ground to a particle size of less than 0.1 mm and a particle content of more than 70%.
优选的，所述固体苛碱的添加量占低阶煤质量的20%~30%；水的添加量为低阶煤质量的2~5倍。Preferably, the added amount of the solid caustic soda occupies 20%-30% of the mass of the low-rank coal; the added amount of water is 2-5 times the mass of the low-rank coal.
优选的，所述加热搅拌的温度为50~100℃，时间为1~5h。Preferably, the temperature of the heating and stirring is 50~100°C, and the time is 1~5h.
本发明还提供了上述制备方法制得的氧化球团粘结剂，其有机组分含量高，粘结性能好，适用性强。The invention also provides the oxidized pellet binder prepared by the above preparation method, which has a high content of organic components, good bonding performance and strong applicability.
本发明还提供了上述氧化球团粘结剂的应用，将其添加至铁矿粉中进行造球，得到氧化球团用铁矿生球。The present invention also provides the application of the above-mentioned oxidized pellet binder, which is added to iron ore powder for pelletizing to obtain green iron ore pellets for oxidized pellets.
本发明的氧化球团粘结剂，可以用于成球性能差的难造球劣质铁矿资源，例如钒钛磁铁矿、磁赤混合矿等，可以增强难造球劣质铁矿表面亲水性，有利于铁矿颗粒成球。The oxidized pellet binder of the present invention can be used for hard-to-ballite and inferior iron ore resources with poor ball-forming properties, such as vanadium-titanium magnetite, maghemite, etc., and can enhance the surface hydrophilicity of the hard-to-ballite inferior iron ore It is beneficial to the iron ore particles to form balls.
优选的，所述铁矿粉先进行润磨或高压辊磨处理再进行造球，可以进一步提高生球强度。Preferably, the iron ore powder is subjected to wet grinding or high-pressure roller milling before pelletizing, which can further improve the green pellet strength.
优选的，所述氧化球团粘结剂的添加量占铁矿粉质量的1%~4%，氧化球团粘结剂中的腐殖酸量占铁矿粉质量的0.2%~0.5%。Preferably, the additive amount of the oxidized pellet binder accounts for 1% to 4% of the mass of the iron ore powder, and the amount of humic acid in the oxidized pellet binder accounts for 0.2% to 0.5% of the mass of the iron ore powder.
优选的，所述制得的铁矿生球于900~1050℃下氧化预热焙烧4~12min后用于氧化球团矿或直接还原铁生产。Preferably, the prepared green iron ore pellets are oxidized and preheated and roasted at 900-1050°C for 4-12 minutes and then used for the production of oxidized pellets or direct reduced iron.
腐殖酸含有羧基、羟基和苯环结构，具备粘结剂分子结构。低阶煤是提取腐殖酸主要来源，但腐殖酸含量差异大，现有提取方法普遍包括抽提、蒸发、干燥、研磨等工序，存在的能耗高、流程长、抽提率较低等问题，且制备的腐殖酸产品为固体状态，在用于氧化球团生产时，分散困难，其粘结作用受到限制。本发明将低阶煤经预氧化发酵提高腐殖酸含量1.2~2倍，再同步提取腐植酸与调浆即得氧化球团粘结剂，并直接与铁矿粉混合制备生球，此时溶解后的腐殖酸形成胶体溶液，能够均匀覆盖在铁矿颗粒表面，显著提高铁矿颗粒的表面亲水性，增大铁矿表面张力；且通过铁矿颗粒表面粘结剂的长链构桥作用将铁矿颗粒连接起来，有利于铁矿颗粒成球，提高生球强度。Humic acid contains carboxyl, hydroxyl and benzene ring structures, and has a binder molecular structure. Low-rank coal is the main source of extraction of humic acid, but the content of humic acid varies greatly. Existing extraction methods generally include extraction, evaporation, drying, grinding and other processes, which have high energy consumption, long process, and low extraction rate. In addition, the prepared humic acid product is in a solid state. When used in the production of oxidized pellets, it is difficult to disperse and its binding effect is limited. In the present invention, low-rank coal undergoes pre-oxidation and fermentation to increase the content of humic acid by 1.2 to 2 times, and then humic acid is extracted simultaneously and the slurry is adjusted to obtain the oxidized pellet binder, which is directly mixed with iron ore powder to prepare green pellets. The dissolved humic acid forms a colloidal solution, which can evenly cover the surface of iron ore particles, significantly improve the surface hydrophilicity of iron ore particles, and increase the surface tension of iron ore; and through the long-chain structure of the binder on the surface of iron ore particles The bridge function connects the iron ore particles, which is beneficial to the iron ore particles to form balls and improve the green ball strength.
有益效果Beneficial effect
（1）由于我国铁矿资源贫、杂，细，成球性能差，采用膨润土粘结剂制备铁矿球团时，膨润土添加量较大。本发明制备的粘结剂粘结性能好，能够改善铁矿成球性能，产品适应性强，可适合于难造球劣质铁矿球团，显著提高生球强度。(1) As my country's iron ore resources are poor, miscellaneous, fine, and poor in ball formation, when using bentonite binder to prepare iron ore pellets, the amount of bentonite added is relatively large. The adhesive prepared by the invention has good bonding performance, can improve the spheroidizing performance of iron ore, has strong product adaptability, can be suitable for inferior iron ore pellets that are difficult to pelletize, and significantly improves the green spheroidizing strength.
（2）以膨润土作为粘结剂，膨润土绝大部分为无机组分，生球焙烧后膨润土将残留在成品球中，降低成品球中的铁品位。根据高炉生产实践，入炉成品球中铁品位每提高1%，高炉焦比下降2%，炼铁产量提高3%，高炉渣量减少20kg/t，因此，采用膨润土粘结剂将大大提高炼铁生产成本，降低生产效率。而本发明制备的粘结剂为有机粘结剂，有机组分含量高，有机组分在氧化球团的预热、焙烧过程中将全部燃烧挥发，对成品球的铁品位不产生影响，相比膨润土球团铁品位得到提高，相应的炼铁产量明显提高及生产成本明显下降。(2) Bentonite is used as the binder. Most of the bentonite is an inorganic component. After the green ball is roasted, the bentonite will remain in the finished ball, reducing the iron grade in the finished ball. According to blast furnace production practice, for every 1% increase in the iron grade of the finished ball into the furnace, the blast furnace coke ratio will decrease by 2%, the ironmaking output will increase by 3%, and the blast furnace slag will be reduced by 20kg/t. Therefore, the use of bentonite binder will greatly improve ironmaking Production costs reduce production efficiency. The binder prepared by the present invention is an organic binder with a high content of organic components. The organic components will all burn and volatilize during the preheating and roasting process of the oxidized pellets, which will not affect the iron grade of the finished pellets. Compared with bentonite pellets, the iron grade is improved, and the corresponding ironmaking output is significantly increased and the production cost is significantly reduced.
（3）本发明通过将低阶煤氧化发酵，以显著提高煤中腐殖酸含量，再同步提取腐植酸与调浆即得氧化球团粘结剂，并直接与铁矿粉混合制备生球，腐殖酸有效成分高，无需将腐殖酸与其他粘结剂配合使用；无需将提取的腐殖酸成分制备成粉末产品，省去了料浆干燥、破碎研磨等工艺步骤，流程短、能耗低、工艺效率高。(3) In the present invention, low-rank coal is oxidized and fermented to significantly increase the humic acid content in the coal, and then the humic acid is extracted simultaneously and the slurry is adjusted to obtain the oxidized pellet binder, which is directly mixed with iron ore powder to prepare green pellets. , The effective components of humic acid are high, and there is no need to use humic acid in conjunction with other binders; there is no need to prepare the extracted humic acid components into powder products, and the process steps such as slurry drying, crushing and grinding are omitted, and the process is short, Low energy consumption and high process efficiency.
本发明的最佳实施方式The best mode of the present invention
下面对本发明做进一步的解释和说明。本发明实施例中选取低阶褐煤为原料，其腐植酸含量为32wt%。将褐煤破碎至10mm以下，在120℃温度下充分氧化发酵6h，进一步将其磨至粒度小于0.1mm颗粒质量占煤粉总质量的85%；在煤粉中加入占其质量25%的固体苛碱和400%的水制得煤浆，将煤浆加热至温度95℃并持续搅拌3h，得到氧化球团粘结剂。The present invention will be further explained and illustrated below. In the embodiment of the present invention, low-rank lignite is selected as the raw material, and its humic acid content is 32 wt%. The lignite is crushed to below 10mm, fully oxidized and fermented at 120℃ for 6h, and further ground to a particle size of less than 0.1mm. The particle mass accounts for 85% of the total mass of pulverized coal; solid caustic which accounts for 25% of its mass is added to the pulverized coal. Alkali and 400% water are used to prepare coal slurry. The coal slurry is heated to a temperature of 95°C and continuously stirred for 3 hours to obtain an oxidized pellet binder.
本发明实施例中选取难造球的钒钛磁铁矿为铁矿原料。钒钛磁铁矿主要成分见表1，通过配加制备的粘结剂进行造球。In the embodiment of the present invention, vanadium-titanium magnetite, which is difficult to pelletize, is selected as the iron ore raw material. The main components of vanadium-titanium magnetite are shown in Table 1, and pellets are made by adding the prepared binder.
表1 钒钛磁铁矿主要化学成分/ wt%Table 1 Main chemical composition of vanadium-titanium magnetite / wt%
TFeTFe FeOFeO SiO 2 SiO 2 CaOCaO MgOMgO Al 2O 3 Al 2 O 3 TiO 2 TiO 2 V 2O 5 V 2 O 5 Na 2O Na 2 O
55.8655.86 33.4033.40 4.304.30 0.590.59 3.673.67 3.073.07 10.7010.70 0.660.66 0.100.10
实施例 1。 Example 1 .
以钒钛磁铁矿为原料造球，原料水分5.0wt%，在钒钛磁铁矿粉中配加占其质量3.0wt%的粘结剂使其造球时水份保持在8.0wt%，充分混合均匀，再将混合料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为3.5次/（0.5m），抗压强度为13.7N/个。Using vanadium-titanium magnetite as raw material for pelletizing, the raw material moisture is 5.0wt%, and 3.0wt% of the binder is added to the vanadium-titanium magnetite powder to keep the moisture at 8.0wt% during pelletizing. Mix thoroughly and evenly, then sieve the mixture to less than 1mm, and use a disc pelletizer to pelletize the pellets. The pelletizing time is 10~12min and the pellet size is 10~12mm. The obtained iron ore green balls were tested, the green balls falling strength was 3.5 times/(0.5m), and the compressive strength was 13.7N/piece.
对比例 1。 Comparative example 1 .
以钒钛磁铁矿为原料造球，原料水分5.0wt%，在钒钛磁铁矿粉中配加占其质量3.0wt%的水份使其造球时水份保持在8.0wt%，再配加占铁矿粉质量1.0wt%的膨润土粘结剂，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为2.3次/（0.5m），抗压强度为11.7N/个。Pellets are pelletized from vanadium-titanium magnetite with a raw material moisture of 5.0wt%, and 3.0wt% of its mass is added to the vanadium-titanium magnetite powder to keep the moisture at 8.0wt% during pelletizing. Add a bentonite binder that accounts for 1.0wt% of the iron ore powder mass, mix well, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize, where the pelletizing time is 10~12min, and the pellet size 10~12mm. The obtained iron ore green balls were tested, the green balls falling strength was 2.3 times/(0.5m), and the compressive strength was 11.7N/piece.
对比例 2。 Comparative example 2 .
以钒钛磁铁矿为原料造球，原料水分5.0wt%，在钒钛磁铁矿粉中配加占其质量3.0wt%的水份使其造球时水份保持在8.0wt%，再配加占铁矿粉质量1.5wt%的膨润土粘结剂，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为3.3次/（0.5m），抗压强度为13.2N/个。Pellets are pelletized from vanadium-titanium magnetite with a raw material moisture of 5.0wt%, and 3.0wt% of its mass is added to the vanadium-titanium magnetite powder to keep the moisture at 8.0wt% during pelletizing. Add a bentonite binder that accounts for 1.5wt% of the iron ore powder mass, mix well, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10~12min, and the pellet size 10~12mm. The obtained iron ore green balls were tested, the green balls falling strength was 3.3 times/(0.5m), and the compressive strength was 13.2N/piece.
比较实施例1与对比例1-2中的生球指标数据，对比例1-2中，为满足铁矿生球落下强度高于3.0次/（0.5m）的最低要求，膨润土粘结剂最低配加量需要达到1.5%以上。实施例1中，本发明通过配加由低阶褐煤制备的粘结剂3.0wt%时（即腐殖酸成分配加量为0.45wt%），生球落下强度及抗压强度均高于膨润土粘结剂配加量1.5wt%时生球强度。表明本发明制备的粘结剂粘结性能好，用量少，能够改善难造球铁矿的成球性能。Comparing the green ball index data in Example 1 and Comparative Example 1-2, in Comparative Example 1-2, in order to meet the minimum requirement of iron ore green ball falling strength higher than 3.0 times/(0.5m), the bentonite binder is the lowest The dosage needs to reach more than 1.5%. In Example 1, when the present invention adds 3.0wt% of binder prepared from low-rank lignite (that is, the humic acid composition distribution is 0.45wt%), the green ball drop strength and compressive strength are both higher than that of bentonite Green ball strength when the amount of binder is 1.5wt%. It shows that the binder prepared by the present invention has good bonding performance and a small amount, and can improve the ball-forming performance of the hard-to-form ductile iron ore.
实施例 2。 Example 2 .
钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量1.0wt%的水份和2.0wt%的粘结剂浆液使其造球时水份保持在8.0wt%，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为8.6次/（0.5m），抗压强度为21.3N/个。The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized. The iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10-12min and the pellet size is 10-12mm. The obtained iron ore green balls were tested, the green balls falling strength was 8.6 times/(0.5m), and the compressive strength was 21.3N/piece.
对比例 3。 Comparative example 3 .
钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量3.0wt%的水份使其造球时水份保持在8.0wt%，再配加占铁矿粉质量1.5wt%的膨润土粘结剂，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为5.7次/（0.5m），抗压强度为18.4N/个。The vanadium-titanium magnetite is pelletized after being pretreated by a high-pressure roller mill for 3 times, and 3.0wt% of its mass is added to the iron ore powder to keep the moisture at 8.0wt% during pelletization, and then added The bentonite binder, which accounts for 1.5wt% of the iron ore powder mass, is fully mixed and evenly mixed, and then the material is sieved to below 1mm, and pelletized by a disc pelletizer. The pelletizing time is 10~12min, and the pellet size is 10~ 12mm. The obtained iron ore green balls were tested, the green balls falling strength was 5.7 times/(0.5m), and the compressive strength was 18.4N/piece.
比较实施例2与对比例3中的生球指标数据，钒钛磁铁矿原料经过高压辊磨预处理后，通过配加由低阶褐煤制备的粘结剂2wt%时（即腐殖酸成分配加量为0.3%），生球落下强度及抗压强度分别达到8.6次/（0.5m）和21.3N/个，远高于膨润土配加量1.5wt%时的落下强度5.7次/（0.5m）和抗压强度18.4N/个。表明本发明制备的粘结剂粘结性能好，能够明显改善难造球铁矿资源的成球性能；用量少，降低铁矿球团生产成本。Comparing the green ball index data in Example 2 and Comparative Example 3, after the raw material of vanadium-titanium magnetite is pretreated by high-pressure roller mill, when 2wt% of binder prepared from low-rank lignite is added (that is, humic acid is formed). The distribution amount is 0.3%), the green ball drop strength and compressive strength reach 8.6 times/(0.5m) and 21.3N/piece respectively, which are much higher than the drop strength of 5.7 times/(0.5%) when the added amount of bentonite is 1.5wt% m) and the compressive strength 18.4N/piece. It shows that the adhesive prepared by the present invention has good bonding performance, can obviously improve the pelletizing performance of the hard-to-form nodular iron ore resources; the amount is small, and the production cost of iron ore pellets is reduced.
进一步比较表2不同粘结剂成品球团矿的主要化学成分，采用本发明制备的粘结剂生产的成品氧化球团中铁品位54.65%，比膨润土粘结剂生产的成品氧化球团铁品位提高1%。根据高炉生产实践，入炉成品球中铁品位提高1%，高炉焦比下降2%，炼铁产量提高3%，高炉渣量减少20kg/t，因此采用本发明制备的粘结剂能够大大降低炼铁生产成本。Further comparing the main chemical components of the finished pellets with different binders in Table 2, the iron grade of the finished oxidized pellets produced by the binder prepared by the present invention is 54.65%, which is higher than the iron grade of the finished oxidized pellets produced by the bentonite binder 1%. According to the blast furnace production practice, the iron grade of the finished ball into the furnace is increased by 1%, the blast furnace coke ratio is reduced by 2%, the iron production is increased by 3%, and the blast furnace slag volume is reduced by 20 kg/t. Therefore, the binder prepared by the invention can greatly reduce the refining rate. Iron production costs.
表2 成品氧化球团的主要化学成分/wt%Table 2 The main chemical composition of the finished oxidized pellets/wt%
 To TFeTFe FeOFeO SiO 2 SiO 2 CaOCaO MgOMgO Al 2O 3 Al 2 O 3 TiO 2 TiO 2 V 2O 5 V 2 O 5 Na 2O Na 2 O
对比例3Comparative example 3 53.6353.63 1.711.71 5.355.35 0.480.48 3.523.52 3.413.41 9.169.16 0.620.62 0.210.21
实施例2 Example 2 54.6554.65 2.012.01 5.075.07 0.430.43 3.473.47 3.563.56 9.249.24 0.620.62 0.260.26
对比例 4。 Comparative Example 4 .
以低阶褐煤为原料，其腐植酸含量为32wt%。将其磨至粒度小于0.1mm颗粒质量占煤粉总质量的85%；在煤粉中加入占其质量25%的固体苛碱和400%的水制得煤浆，将煤浆加热至温度95℃并持续搅拌3h，得到氧化球团粘结剂。钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量1.0wt%的水份和2.0wt%的粘结剂浆液使其造球时水份保持在8.0wt%，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为2.1次/（0.5m），抗压强度为8.3N/个，爆裂温度为510℃。Using low-rank lignite as raw material, its humic acid content is 32wt%. Grind it to a particle size of less than 0.1mm. The particle mass accounts for 85% of the total mass of pulverized coal; add 25% of the mass of solid caustic soda and 400% of water to the pulverized coal to prepare a coal slurry, and heat the coal slurry to a temperature of 95 ℃ and continue to stir for 3h to obtain the oxidized pellet binder. The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized. The iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10-12min and the pellet size is 10-12mm. The obtained iron ore green balls were tested, the green balls falling strength was 2.1 times/(0.5m), the compressive strength was 8.3N/piece, and the burst temperature was 510℃.
对比例 5。 Comparative Example 5 .
以对比例4得到氧化球团粘结剂。钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量4.0wt%的粘结剂浆液使其造球时水份保持在8.0wt%，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为2.8次/（0.5m），抗压强度为9.6N/个，爆裂温度为460℃。In Comparative Example 4, an oxidized pellet binder was obtained. The vanadium-titanium magnetite is pelletized after being pretreated by a high-pressure roller mill for 3 times, and a binder slurry of 4.0wt% of its mass is added to the iron ore powder to keep the water content at 8.0wt% during pelletizing. Mix evenly, then sieve the material to below 1mm, and use a disc pelletizer to pelletize the pellets. The pelletizing time is 10~12min and the pellet size is 10~12mm. The obtained iron ore green balls were tested and found that the falling strength of the green balls was 2.8 times/(0.5m), the compressive strength was 9.6N/piece, and the burst temperature was 460℃.
比较实施例1-2与对比例4-5中的生球指标数据，当低阶褐煤不经过氧化发酵处理直接制备粘结剂浆液时，所制得的生球无法满足生产要求。Comparing the green ball index data in Example 1-2 and Comparative Example 4-5, when the binder slurry is directly prepared from low-rank lignite without oxidative fermentation treatment, the prepared green ball cannot meet the production requirements.
实施例 3低阶褐煤在120℃温度下充分氧化发酵6h，进一步将其磨至粒度小于0.1mm颗粒质量占煤粉总质量的85%；在煤粉中加入占其质量20%的固体苛碱和400%的水制得煤浆，将煤浆加热至温度80℃并持续搅拌3h，得到氧化球团粘结剂。钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量1.0wt%的水份和2.0wt%的粘结剂浆液使其造球时水份保持在8.0wt%，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为7.3次/（0.5m），抗压强度为20.6N/个，爆裂温度为550℃。 Example 3 Low-rank lignite was fully oxidized and fermented at a temperature of 120°C for 6 hours, and then ground to a particle size of less than 0.1 mm. The particle mass accounted for 85% of the total mass of pulverized coal; solid caustic alkali accounting for 20% of its mass was added to the pulverized coal Prepare a coal slurry with 400% water. The coal slurry is heated to a temperature of 80°C and continuously stirred for 3 hours to obtain an oxidized pellet binder. The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized. The iron ore powder is mixed with 1.0wt% of its mass and 2.0wt% of binder slurry to make the water during pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10-12min and the pellet size is 10-12mm. The obtained iron ore green balls were tested and found that the falling strength of the green balls was 7.3 times/(0.5m), the compressive strength was 20.6N/piece, and the burst temperature was 550°C.
实施例 4。 Example 4 .
以实施例3所得的发酵后的煤粉为原料，加入占其质量30%的固体苛碱和400%的水制得煤浆，将煤浆加热至温度80℃并持续搅拌3h，得到氧化球团粘结剂。钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量1.0wt%的水份和2.0wt%的粘结剂浆液使其造球时水份保持在8.0wt%，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为9.6次/（0.5m），抗压强度为22.1N/个，爆裂温度为530℃。Using the fermented coal powder obtained in Example 3 as raw materials, adding 30% of the mass of solid caustic soda and 400% of water to prepare a coal slurry, the coal slurry is heated to a temperature of 80°C and continuously stirred for 3 hours to obtain oxidized pellets Group binder. The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized. The iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10-12min and the pellet size is 10-12mm. The obtained iron ore green balls were tested and found that the falling strength of the green balls was 9.6 times/(0.5m), the compressive strength was 22.1N/piece, and the burst temperature was 530°C.
对比例 6。 Comparative Example 6 .
以实施例3所得的发酵后的煤粉为原料，加入占其质量15%的固体苛碱和400%的水制得煤浆，将煤浆加热至温度80℃并持续搅拌3h，得到氧化球团粘结剂。钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量1.0wt%的水份和2.0wt%的粘结剂浆液使其造球时水份保持在8.0wt%，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为2.8次/（0.5m），抗压强度为12.8N/个，爆裂温度为480℃。Using the fermented coal powder obtained in Example 3 as raw materials, adding 15% of its mass of solid caustic soda and 400% of water to prepare a coal slurry, heat the coal slurry to a temperature of 80°C and continue stirring for 3 hours to obtain oxidized pellets Group binder. The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized. The iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10-12min and the pellet size is 10-12mm. The obtained iron ore green balls were tested, and the green balls had a falling strength of 2.8 times/(0.5m), a compressive strength of 12.8N/piece, and a burst temperature of 480°C.
对比例 7。 Comparative Example 7 .
以实施例3所得的发酵后的煤粉为原料，加入占其质量35%的固体苛碱和400%的水制得煤浆，将煤浆加热至温度80℃并持续搅拌3h，得到氧化球团粘结剂。钒钛磁铁矿经高压辊磨3次预处理后进行造球，在铁矿粉中配加占其质量1.0wt%的水份和2.0wt%的粘结剂浆液使其造球时水份保持在8.0wt%，充分混合均匀，再将物料过筛至1mm以下，采用圆盘造球机进行造球，其中造球时间10~12min，球团尺寸10~12mm。所得铁矿生球经检测，生球落下强度为3.2次/（0.5m），抗压强度为13.2N/个，爆裂温度为390℃。Using the fermented coal powder obtained in Example 3 as raw materials, adding 35% of the mass of solid caustic soda and 400% water to prepare a coal slurry. The coal slurry is heated to a temperature of 80°C and continuously stirred for 3 hours to obtain oxidized pellets. Group binder. The vanadium-titanium magnetite is pretreated by high-pressure roller mill for 3 times and then pelletized. The iron ore powder is mixed with 1.0wt% water and 2.0wt% binder slurry to make the water when pelletizing. Keep it at 8.0wt%, mix thoroughly, and then sieve the material to below 1mm. Use a disc pelletizer to pelletize the pellets. The pelletizing time is 10-12min and the pellet size is 10-12mm. The obtained iron ore green balls were tested, and the green balls had a falling strength of 3.2 times/(0.5m), a compressive strength of 13.2N/piece, and a burst temperature of 390°C.
比较实施例3-4与对比例6-7中的生球指标数据，当固体苛碱配加量在优选范围之外时，所制得的粘结剂浆液无法同时满足铁矿生球落下强度高于3.0次/（0.5m）和爆裂温度大于450℃的最低要求。Comparing the green ball index data in Example 3-4 and Comparative Example 6-7, when the dosage of solid caustic alkali is outside the preferred range, the prepared binder slurry cannot satisfy the iron ore green ball falling strength at the same time. The minimum requirement is higher than 3.0 times/(0.5m) and burst temperature higher than 450℃.
实施例 5。 Example 5 .
取另一种低阶煤为原料，其腐殖酸含量51%，在150℃温度下充分氧化发酵3h，腐殖酸含量达到64%。在煤粉中加入占其质量20%的固体苛碱和200%的水制得煤浆，将煤浆加热至温度60℃并持续搅拌5h，得到氧化球团粘结剂浆液。粘结剂用于磁铁矿精粉造球，粘结剂配入量1%，经过高压辊磨后造球，造球时间10~12min，生球粒径14~16mm。生球落下强度8.1次/(0.5m)，抗压强度27.8N，爆裂温度为570℃，均满足球团生产要求。Take another low-rank coal as the raw material, its humic acid content is 51%, and fully oxidized and fermented at 150°C for 3 hours, and the humic acid content reaches 64%. A coal slurry is prepared by adding 20% of the mass of solid caustic soda and 200% of the coal powder to the coal powder. The coal slurry is heated to a temperature of 60°C and continuously stirred for 5 hours to obtain an oxidized pellet binder slurry. The binder is used to pelletize the magnetite concentrate. The binder content is 1%, and the pellets are pelletized after high-pressure roller milling. The pelletizing time is 10-12 minutes, and the green pellet size is 14-16mm. The green ball has a drop strength of 8.1 times/(0.5m), a compressive strength of 27.8N, and a burst temperature of 570°C, which all meet the requirements of pellet production.
实施例 6。 Example 6 .
取实施例5制得的氧化球团粘结剂浆液，用于赤铁矿精粉造球，粘结剂配入量1.5%，经过高压辊磨后造球，造球时间10~12min，生球粒径14~16mm。生球落下强度9.2次/(0.5m)，抗压强度25.2N，爆裂温度为520℃，均满足球团生产要求。将制得的合格生球进行氧化预热焙烧，预热温度1000℃，预热时间4min，抗压强度达1050N/个，氧化预热球团用于直接还原铁生产。Take the oxidized pellet binder slurry prepared in Example 5 and use it to pelletize hematite concentrate. The binder content is 1.5%. The pellets are pelletized after high-pressure roller milling. The pelletizing time is 10-12 minutes. The ball size is 14~16mm. The drop strength of the green ball is 9.2 times/(0.5m), the compressive strength is 25.2N, and the burst temperature is 520℃, which all meet the requirements of pellet production. The prepared qualified green balls are oxidized and preheated and roasted at a preheating temperature of 1000°C, a preheating time of 4 minutes, and a compressive strength of 1050N/piece. The oxidized preheated pellets are used for direct reduced iron production.
实施例 7。 Example 7 .
取实施例5制得的氧化球团粘结剂浆液，用于普通铁精粉造球，粘结剂配入量1.0%，造球时间10~12min，生球粒径14~16mm。生球落下强度8.7次/(0.5m)，抗压强度23.2N，爆裂温度为580℃，均满足球团生产要求。将制得的合格生球进行氧化预热焙烧，预热温度900℃，预热时间5min，抗压强度达970N/个，氧化预热球团用于直接还原铁生产。The oxidized pellet binder slurry prepared in Example 5 was used to pelletize ordinary iron fine powder, the binder content was 1.0%, the pelletizing time was 10-12 minutes, and the green pellet size was 14-16mm. The green ball has a drop strength of 8.7 times/(0.5m), a compressive strength of 23.2N, and a burst temperature of 580°C, which all meet the requirements of pellet production. The prepared qualified green pellets are oxidized and preheated and roasted at a preheating temperature of 900°C, a preheating time of 5 minutes, and a compressive strength of 970N/piece. The oxidized preheated pellets are used for the production of direct reduced iron.

Claims (10)

  1. 一种由低阶煤制造氧化球团粘结剂的方法，其特征在于：将低阶煤破碎后进行氧化发酵，再加入固体苛碱和水调制浆液，经加热搅拌即得氧化球团粘结剂；所述固体苛碱的添加量占低阶煤质量的20%~30%；水的添加量为低阶煤质量的2~5倍。A method for producing oxidized pellet binder from low-rank coal, which is characterized in that: the low-rank coal is crushed and then subjected to oxidative fermentation, then solid caustic alkali and water are added to prepare a slurry, and the oxidized pellet binder is obtained by heating and stirring Agent; the addition of the solid caustic soda accounts for 20% to 30% of the quality of low-rank coal; the addition of water is 2 to 5 times the quality of low-rank coal.
  2. 根据权利要求1所述的一种由低阶煤制造氧化球团粘结剂的方法，其特征在于：所述低阶煤中的腐植酸含量不低于25wt%，经破碎至粒度小于10mm。The method for producing oxidized pellet binder from low-rank coal according to claim 1, wherein the humic acid content in the low-rank coal is not less than 25wt%, and the particle size is less than 10mm after being crushed.
  3. 根据权利要求2所述的一种由低阶煤制造氧化球团粘结剂的方法，其特征在于：所述低阶煤中的腐植酸含量不低于30wt%。The method for producing an oxidized pellet binder from low-rank coal according to claim 2, wherein the content of humic acid in the low-rank coal is not less than 30wt%.
  4. 根据权利要求1所述的一种由低阶煤制造氧化球团粘结剂的方法，其特征在于：所述氧化发酵的温度为80~200℃，时间为2~10h，且氧化发酵完成后进一步将低阶煤磨至粒度小于0.1mm颗粒含量达到70%以上。The method for producing an oxidized pellet binder from low-rank coal according to claim 1, wherein the temperature of the oxidative fermentation is 80~200°C, the time is 2~10h, and after the oxidative fermentation is completed The low-rank coal is further ground until the particle size is less than 0.1mm and the particle content reaches more than 70%.
  5. 根据权利要求1所述的一种由低阶煤制造氧化球团粘结剂的方法，其特征在于：所述加热搅拌的温度为50~100℃，时间为1~5h。The method for producing an oxidized pellet binder from low-rank coal according to claim 1, wherein the heating and stirring temperature is 50-100°C, and the time is 1-5h.
  6. 权利要求1-5任一项所述的一种由低阶煤制造氧化球团粘结剂的方法制得的氧化球团粘结剂。The oxidized pellet binder prepared by the method for producing oxidized pellet binder from low-rank coal according to any one of claims 1-5.
  7. 权利要求6所述的氧化球团粘结剂的应用，其特征在于：将其添加至铁矿粉中进行造球，得到氧化球团用铁矿生球。The application of the oxidized pellet binder according to claim 6, characterized in that it is added to iron ore powder for pelletizing to obtain green iron ore pellets for oxidized pellets.
  8. 根据权利要求7所述的氧化球团粘结剂的应用，其特征在于：所述铁矿粉先进行润磨或高压辊磨处理再进行造球。The application of the oxidized pellet binder according to claim 7, wherein the iron ore powder is first subjected to wet grinding or high-pressure roller milling treatment before pelletizing.
  9. 根据权利要求8所述的氧化球团粘结剂的应用，其特征在于：所述氧化球团粘结剂的添加量占铁矿粉质量的1%~4%，氧化球团粘结剂中的腐殖酸量占铁矿粉质量的0.2%~0.5%。The application of the oxidized pellet binder according to claim 8, wherein the additive amount of the oxidized pellet binder accounts for 1% to 4% of the mass of the iron ore powder, and the oxidized pellet binder is The amount of humic acid accounts for 0.2% to 0.5% of the mass of iron ore powder.
  10. 根据权利要求7~9所述的氧化球团粘结剂的应用，其特征在于：所述制得的铁矿生球于900~1050℃下氧化预热焙烧4~12min后用于氧化球团矿或直接还原铁生产。The application of the oxidized pellet binder according to claims 7-9, characterized in that: the prepared iron ore green pellets are oxidized, preheated and roasted at 900~1050°C for 4~12 minutes and then used for oxidized pellets. Mine or direct reduced iron production.
PCT/CN2021/083574 2020-03-30 2021-03-29 Oxidized pellet binding agent made from low-rank coal, preparation method for same, and applications thereof WO2021197258A1 (en)

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CN114854984A (en) * 2022-04-13 2022-08-05 昆明理工大学 Preparation method and application method of composite binder for producing oxidized pellets
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