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CN-121976035-A - High-silicon fluxed pellet binder and preparation method thereof, fluxed pellet and preparation method thereof

CN121976035ACN 121976035 ACN121976035 ACN 121976035ACN-121976035-A

Abstract

The invention discloses a high-silicon fluxed pellet binder and a preparation method thereof, fluxed pellets and a preparation method thereof, wherein the fluxed pellets comprise 66-78% of calcined desulfurization ash, 20-32% of converter OG mud, 1-3% of pregelatinized starch and 0.5-1.5% of guar gum in percentage by weight on a dry basis. The invention prepares the novel binder suitable for the high-silicon flux type pellets by taking the desulfurized fly ash as a calcium-based material and the converter mud as an iron-based material and adding the high-molecular organic matters as auxiliary materials, thereby realizing the recycling of waste and green resources of ferrous metallurgy and improving the quality of the high-silicon flux type pellets.

Inventors

  • LI JINLIAN
  • Shi Miqiang
  • SUN TAO
  • JIN JIN
  • ZOU QIANG
  • YAN QINGSHUANG
  • XIA FENG
  • LIU XINZHANG
  • HE CHONG
  • LI ZHEN

Assignees

  • 鞍钢股份有限公司

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. The high-silicon fluxed pellet binder is characterized by comprising the following components in percentage by weight on a dry basis: 66% -78% of calcined desulfurization ash, 20% -32% of converter OG mud, 1% -3% of pregelatinized starch and 0.5% -1.5% of guar gum.
  2. 2. The high silicon fluxed pellet binder of claim 1, wherein the weight percentage of CaO/CaSO 4 in the calcined desulfurization ash is greater than or equal to 1.0; the moisture content of the converter OG mud is <1%; The index of the pregelatinized starch is that the viscosity of a 2% aqueous solution of the pregelatinized starch is more than 65pas; the guar gum has the indexes that the viscosity of a guar gum 2% aqueous solution is more than 2000pas; The granularity composition of the high-silicon fluxed pellet binder comprises more than 96% of particles with the particle size of less than 0.044mm in percentage by weight.
  3. 3. A method of preparing the high silicon fluxed pellet binder of any one of claims 1-2, comprising the steps of: (1) Roasting the desulfurization ash at medium temperature to obtain calcined desulfurization ash, wherein the calcined desulfurization ash is a composite of CaO and CaSO 4 ; (2) Drying the converter OG mud at a low temperature to obtain pretreated converter OG mud; (3) According to the dry basis ratio, mixing the calcined desulfurization ash obtained in the step (1), the pretreated converter OG mud obtained in the step (2), pregelatinized starch and guar gum, and then performing ball milling and sieving to obtain the high-silicon fluxed pellet binder.
  4. 4. The method for preparing the high-silicon fluxed pellet binder according to claim 3, wherein in the step (1), the medium-temperature roasting temperature is 650-700 ℃, and the medium-temperature roasting time is 10-30 min; In the step (2), the low-temperature drying temperature is 110-150 ℃, the low-temperature drying time is 20-40 min, and the moisture content of the pretreated converter OG mud is less than 1%; In the step (3), the ball milling time is 15-35 min, and the sieving number is 200 meshes.
  5. 5. The preparation method of the fluxed pellets is characterized by comprising the following steps: Mixing, pelletizing and screening a high-silicon fluxed pellet binder and iron ore concentrate in sequence to obtain green pellets, roasting the green pellets to obtain fluxed pellets, wherein the high-silicon fluxed pellet binder is the high-silicon fluxed pellet binder according to any one of claims 1-2 or the high-silicon fluxed pellet binder prepared by the preparation method according to any one of claims 3-4, and the mixing ratio is as follows: W 1 = （R×W 2 ）/（W 3 +R)×100; Wherein W 1 is the mass percent (%) of the iron concentrate, W 2 is the sum (%) of the mass percent of SiO 2 in the iron concentrate and the high-silicon fluxed pellet binder, and R is the target binary basicity of the pellet (CaO/SiO 2 ）,W 3 is the mass percent (%) of CaO in the high-silicon fluxed pellet binder).
  6. 6. The method for preparing the fluxed pellets according to claim 5, wherein the roasting process comprises drying, preheating, roasting and cooling in sequence, wherein the drying temperature is 20-500 ℃, and the drying time is 7-15 min; the preheating temperature is 500-1050 ℃, and the preheating time is 10-15 min; The roasting temperature is 1150-1200 ℃, and the roasting time is 10-20 min.
  7. 7. The method for producing fluxed pellets as defined in claim 5, wherein the target binary basicity r=cao/SiO 2 of pellets is in the range of 0.6 to 1.0.
  8. 8. The fluxed pellet prepared by the preparation method according to any one of claims 5 to 7, wherein the fluxed pellet has a compressive strength of 2000 to 5000n, a drum strength of 85 to 97%, an expansion ratio of 5 to 15%, a reduction degree of 65 to 90% and a pulverization rate RDI +3.15mm to 90%.
  9. 9. The fluxed pellet of claim 8, wherein the basicity of the fluxed pellet is 0.6 to 1.0.
  10. 10. The fluxed pellet of claim 8, wherein the fluxed pellet comprises 57-63% of TFe, 0.3-2% of FeO, 5.5-8% of SiO 2 , 4-10% of CaO and 0.1-1.0% of MgO.

Description

High-silicon fluxed pellet binder and preparation method thereof, fluxed pellet and preparation method thereof Technical Field The invention relates to the technical field of sintered pellets, in particular to a high-silicon fluxed pellet binder and a preparation method thereof, fluxed pellets and a preparation method thereof. Background Compared with the sintering process, the pellet process has remarkable advantages in the aspects of energy conservation, emission reduction and environmental improvement. Compared with acid pellets, the fluxed pellets have the advantages of high reduction degree, high softening initial temperature, narrow reflow zone, low expansion rate and the like, and are one of the main raw materials for realizing high quality, high yield, energy conservation and emission reduction in blast furnace ironmaking. The flux pellet is prepared through mixing finely ground limestone powder, iron ore powder, bentonite and other material, pelletizing in a disc pelletizer, preheating in a grate-rotary kiln or a belt roaster, and roasting. The flux pellets are generally produced by adding limestone to increase CaO content to adjust the alkalinity, and the alkalinity is generally 0.8-1.2. When the SiO 2 content in the iron concentrate powder is higher, more limestone is needed to be added, the consumption of the binder is increased, and the SiO 2 content of the pellet is increased. The patent with publication number CN104988308A discloses a preparation method and application of an iron-rich composite binder for iron ore pellets, and the iron-rich composite binder for iron ore pellets comprises iron mud and a tackifier, wherein the tackifier is carboxymethyl cellulose, the total iron content in the iron-rich composite binder is 35-40 wt%, and the content of (SiO 2+Al2O3) is less than or equal to 25wt%. The patent with the publication number of CN106191432A discloses a production process of a novel iron-containing metallurgical pellet binder, which comprises the following specific operations of (1) preparing materials according to the following weight percentages, 88-92% of dedusting plaster, 4-6% of hydroxypropyl methyl cellulose and 4-6% of sodium carboxymethyl cellulose, (2) mixing the raw materials in the step (1), and (3) crushing the materials in the step (2) to more than 200 meshes to form a binding material with the viscosity value of more than 2000pas, thereby obtaining the novel metallurgical pellet binder product. The patent with the publication number of CN105861818A discloses high-efficiency composite bentonite for pellets, which comprises, by weight, 60-80 parts of bentonite, 12-26 parts of organic cellulose, 5-10 parts of sodium carbonate, 7-14 parts of magnesium oxide, 4-6 parts of diboron trioxide and 5-11 parts of high-temperature explosion-proof agent. The patent with publication number CN108796216A discloses a pellet iron-magnesium composite binder and a preparation and use method thereof, wherein the pellet iron-magnesium composite binder comprises, by weight, 0.02-0.10 part of an organic polymer material, 0.06-0.30 part of a thickener, 99.64-99.90 parts of an iron-magnesium additive, one or two of tragacanth gum and tamarind polysaccharide gum, the thickener is a mixture of polyethylene methyl ether and polyacrylamide, and the iron-magnesium additive is one or two of magnesia powder and iron-containing materials. The patent with publication number CN104164560A discloses a sodium humate binder solution for iron ore pellets, a preparation method and application thereof, wherein the solute of the sodium humate binder solution consists of sodium humate, sodium hydroxide and a viscosity regulator, the solvent is water, the viscosity regulator consists of one or more of soluble salts of Al 3+、Fe3+、Ca2+、Mg2+, and the preparation method comprises the steps of dissolving sodium humate in NaOH solution, adding the viscosity regulator and stirring uniformly. The patent with publication number CN105087912A discloses a preparation method and application of humic acid modified bentonite for iron ore pellets, wherein natural calcium bentonite is crushed and ground, then mixed solution of sodium humate and organic quaternary ammonium salt is added into the ground natural calcium bentonite in a spraying mode, uniformly mixed, and then pressed into a block for forming, and the obtained block is aged, dried, crushed and ground in sequence to obtain the humic acid modified bentonite. In conclusion, when the content of SiO 2 in the iron concentrate is less than 4%, the method can be used for preparing normal fluxed pellets, when the content of SiO 2 in the iron concentrate is 4% -6%, the method can be used for preparing medium silicon fluxed pellets, when the content of SiO 2 in the iron concentrate is more than 6%, the method can be used for preparing high silicon fluxed pellets, and because the content of SiO 2 in the high silicon fluxed pellets is high, a large amount of calcium flux needs to be