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CN-121976034-A - High magnesium aluminate sintered ore and production method thereof

CN121976034ACN 121976034 ACN121976034 ACN 121976034ACN-121976034-A

Abstract

The invention relates to the field of iron-making sintering technology, and discloses a high-magnesium aluminate sintered ore and a production method thereof, wherein the high-magnesium aluminate sintered ore comprises the steps of proportioning, mixing, granulating, sintering, cooling, crushing and screening, wherein high-silicon high-aluminum economic mineral powder and return ore are selected as iron-containing raw materials, dolomite powder is used for partially replacing magnesite powder and quicklime, the moisture of the mixture is controlled to be 6.8% -7.2%, the mass fraction of fine particles with the particle size of less than 3mm is controlled to be 30% -40%, the thickness of a material layer is not less than 800mm, the ignition temperature is 1150-1250 ℃ and the sintering negative pressure is not less than 14kPa, so that the contents of silicon dioxide, magnesium oxide, calcium oxide, alkalinity R and FeO of the obtained sintered ore are in a preset range, the mass fraction of 5-40 mm is not less than 80%, and the comprehensive cost and the unit sintering fuel consumption of a flux are reduced on the premise that the components and metallurgical performance of the sintered ore are ensured to be stable and up to standard.

Inventors

  • YU XIAOBO
  • WANG DIANLIANG
  • DONG HONGCHANG
  • ZHU TIANWEI
  • GAO SHUANGLONG
  • FAN HAIWEI
  • LI ZHEN
  • CHEN XIUJUN
  • LI BEIBEI
  • MIAO SHULEI

Assignees

  • 日照钢铁控股集团有限公司

Dates

Publication Date
20260505
Application Date
20260204

Claims (10)

  1. 1. The production method of the high-magnesium aluminate agglomerate comprises the following steps: s1, adding an iron-containing mineral raw material, a flux raw material, a fuel raw material, return ores and other ingredients into a mixture according to mass percentage, wherein the iron-containing mineral raw material comprises at least two of high-alumina powder ore, high-silica powder ore and sea sand magnetite, the flux raw material comprises dolomite powder, magnesite powder and quicklime, the fuel raw material comprises coke powder and anthracite, the silicon dioxide content in the prepared mixture is 6.5% -8.0%, the magnesium oxide content is 4.5% -5.5%, the calcium oxide content is 3.6% -4.6%, and the alkalinity R=CaO/SiO 2 is 0.45-0.60; S2, adding water into the mixture for mixing and granulating, wherein the water content of the mixture is controlled to be 6.8% -7.2%, and thus mixture particles with preset particle size distribution are obtained; S3, paving the mixture particles on a trolley of a sintering machine to form a material layer, wherein the thickness of the material layer is not less than 800mm, igniting the material layer by adopting converter gas and introducing oxygen-enriched air above the trolley, controlling the ignition temperature to 1150-1250 ℃, and sintering under the negative pressure condition not lower than 14kPa to obtain a sintered ore cake; S4, cooling the sinter cake, and crushing and screening to obtain the high-magnesium aluminate sinter product with qualified granularity.
  2. 2. The method for producing high-magnesium aluminate sintered ore according to claim 1, wherein the addition of dolomite powder, magnesite powder and quicklime in the flux raw material is 1.5% -2.0% of the total mass of the mixture, the magnesite powder is 8.0% -10.0% of the total mass of the mixture, and the quicklime is 2.5% -3.5% of the total mass of the mixture.
  3. 3. The method for producing high magnesium aluminate agglomerate according to claim 1, wherein the total addition of the fuel raw materials is 5.8% -6.2% of the total mass of the mixture, wherein the coke powder is 3.0% -3.5% of the total mass of the mixture, and the anthracite coal is 1.5% -2.0% of the total mass of the mixture.
  4. 4. The method for producing high-magnesium aluminate sintered ore according to claim 1, wherein the iron-containing mineral raw materials comprise, by mass, 15% -25% of high-alumina powder ore, 10% -20% of sea sand magnetite and 15% -20% of high-silica powder ore, and the balance of other iron ore powder and return ore.
  5. 5. The method for producing high magnesium aluminate agglomerate according to claim 1, wherein the sintering end point temperature is controlled to 900-1000 ℃, and the sintering end point criterion is that the position of the combustion zone in the material layer is close to the bottom quarter of the trolley.
  6. 6. The method for producing high magnesium aluminate agglomerate according to claim 1, wherein the fuel raw material addition amount and ignition heat degree are set so that the content of iron oxide in FeO form in the obtained high magnesium aluminate agglomerate is in the range of 11.0% -14.0%.
  7. 7. The method for producing high-magnesium aluminate agglomerate according to claim 1, wherein the amount of dolomite powder is adjusted relative to the amounts of magnesite powder and quicklime, and the magnesia and the calcium oxide provided by the dolomite powder meet the requirements that the magnesia content in the agglomerate is 4.5% -5.5%, the calcium oxide content is 3.6% -4.6% and the alkalinity R=CaO/SiO 2 is 0.45% -0.60.
  8. 8. The method for producing high magnesium aluminate sintered ore according to claim 1, wherein the mass fraction of fine particles with the granularity smaller than 3mm in the mixture is controlled to be 30% -40%.
  9. 9. The high-magnesium aluminate agglomerate is prepared by adopting the production method of the high-magnesium aluminate agglomerate according to any one of claims 1-8, and is characterized in that the chemical components of the high-magnesium aluminate agglomerate are 6.5% -8.0% of silicon dioxide, 4.5% -5.5% of magnesium oxide, 3.6% -4.6% of calcium oxide, 0.45% -0.60% of alkalinity R=CaO/SiO 2 and 11.0% -14.0% of FeO.
  10. 10. The high-magnesium aluminate agglomerate according to claim 9, wherein the particle size distribution of the high-magnesium aluminate agglomerate satisfies the mass fraction of 5 mm-40 mm.

Description

High magnesium aluminate sintered ore and production method thereof Technical Field The invention relates to the technical field of iron-making sintering technology, in particular to a high-magnesium aluminate sintered ore and a production method thereof. Background In blast furnace ironmaking production, sinter is one of the highest-proportion furnace charges, and the component stability, metallurgical performance and cost level of the sinter directly influence the fuel ratio, slag amount and molten iron cost of the blast furnace. With the development and utilization of low-grade high-silicon high-aluminum economic ores in large quantities, acid sintered ores are widely used for matching blast furnace smelting by virtue of lower alkalinity and higher magnesium-aluminum ratio so as to realize the low cost of the raw fuel structure. In the prior art, in order to utilize high-silicon high-aluminum economic ores such as coarse printing ores and laterite nickel ores, magnesite powder is added into sintering ingredients in a large proportion, so that the magnesium oxide content in the sintering ores is increased, the magnesium-aluminum ratio of the acidic sintering ores is increased from about 1.0 to about 1.4, and magnesium fluxes such as serpentine are added to the side of a blast furnace to balance the magnesium-aluminum ratio of slag. Although the process can meet the requirement of the blast furnace on the MgO content to a certain extent, the magnesite powder has higher price and large decomposition heat absorption, and is easy to cause higher sintering flux cost, increased fuel ratio and reduced blast furnace utilization coefficient. In summary, under the condition that low-grade high-silicon high-aluminum economic ore is mixed in a large proportion, the existing acid sinter production scheme often depends on high-cost magnesite powder and a magnesia flux at the side of a blast furnace to improve the magnesium content of sinter and slag, and the synchronous reduction of the comprehensive cost of the flux and the burnup of unit sinter is difficult to realize on the premise that the components and metallurgical properties of the sinter meet the use requirements of the blast furnace, so that the economic stable production of the high-magnesium aluminate sinter is restricted. Disclosure of Invention The invention aims to provide a high-magnesium aluminate sintered ore and a production method thereof, which are used for solving the problems that under the condition of using high-silicon high-aluminum economic ore in a large proportion, the comprehensive cost of a flux and the unit sintering burn-up are difficult to reduce on the premise of ensuring that the chemical components and metallurgical properties of the sintered ore reach the stable standards. In order to achieve the aim of the invention, the invention adopts the following technical scheme that the method for producing the high-magnesium aluminate agglomerate comprises the following steps: s1, adding an iron-containing mineral raw material, a flux raw material, a fuel raw material, return ores and other ingredients into a mixture according to mass percentage, wherein the iron-containing mineral raw material comprises at least two of high-alumina powder ore, high-silica powder ore and sea sand magnetite, the flux raw material comprises dolomite powder, magnesite powder and quicklime, the fuel raw material comprises coke powder and anthracite, the silicon dioxide content in the prepared mixture is 6.5% -8.0%, the magnesium oxide content is 4.5% -5.5%, the calcium oxide content is 3.6% -4.6%, and the alkalinity R=CaO/SiO 2 is 0.45-0.60; S2, adding water into the mixture for mixing and granulating, wherein the water content of the mixture is controlled to be 6.8% -7.2%, and thus mixture particles with preset particle size distribution are obtained; S3, paving the mixture particles on a trolley of a sintering machine to form a material layer, wherein the thickness of the material layer is not less than 800mm, igniting the material layer by adopting converter gas and introducing oxygen-enriched air above the trolley, controlling the ignition temperature to 1150-1250 ℃, and sintering under the negative pressure condition not lower than 14kPa to obtain a sintered ore cake; S4, cooling the sinter cake, and crushing and screening to obtain the high-magnesium aluminate sinter product with qualified granularity. Preferably, the addition amount of dolomite powder, magnesite powder and quicklime in the flux raw material is 1.5% -2.0% of the total mass of the mixture, 8.0% -10.0% of the total mass of the mixture, and 2.5% -3.5% of the total mass of the mixture. Preferably, the total addition amount of the fuel raw materials is 5.8% -6.2% of the total mass of the mixture, wherein the coke powder accounts for 3.0% -3.5% of the total mass of the mixture, and the anthracite coal accounts for 1.5% -2.0% of the total mass of the mixture. Preferably, the iron-containing min