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CN-121974581-A - Portland cement clinker based on marl and preparation method thereof

CN121974581ACN 121974581 ACN121974581 ACN 121974581ACN-121974581-A

Abstract

The invention discloses a Portland cement clinker based on marl and a preparation method thereof, and relates to the technical field of cement. The method comprises the steps of crushing, grinding and drying natural marl rock, spraying and activating mixed impregnating solution containing sodium hydroxide, lanthanum nitrate and cerium nitrate, drying and roasting at low temperature to obtain modified marl rock powder, mixing the powder with calcium carbonate, quartz powder, ferric oxide, dihydrate gypsum, calcium fluoride and barium carbonate, pressing the mixture into a green body, and finally carrying out two-stage mineralization calcination on the green body in sequence, introducing oxygen-enriched air in a heat preservation stage for continuous calcination, and cooling to obtain cement clinker. The invention uses the marl as the main raw material, and the cement clinker obtained by the impregnation activation and the multi-stage calcination process has excellent sulfate erosion resistance.

Inventors

  • YANG JINHUA
  • WU YIFENG
  • MIN JUNTAO
  • CHEN HONGMEI
  • NING JIANFENG
  • Wan Jinyuan

Assignees

  • 湖北白兆山水泥有限公司

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. 1. The preparation method of the silicate cement clinker based on the marl is characterized by comprising the following steps of: (1) Crushing, grinding and drying natural marl to obtain marl powder; (2) Mixing sodium hydroxide solution, lanthanum nitrate and cerium nitrate to prepare mixed impregnating solution; (3) Uniformly spraying the mixed impregnating solution into the marl powder, and standing for activation to obtain activated powder; (4) Drying and roasting the activated powder at low temperature, and grinding a roasting product to obtain modified shale powder; (5) Mixing the modified shale powder with calcium carbonate, quartz powder, ferric oxide, dihydrate gypsum, calcium fluoride and barium carbonate, and performing compression molding to obtain a blank; (6) Carrying out two-stage mineralization calcination on the green body; (7) And (5) preserving heat, introducing oxygen-enriched air, continuously calcining, and cooling after the calcining is finished.
  2. 2. The method for preparing Portland cement clinker based on marl according to claim 1, wherein in the step (1), the natural marl is ground to a grain size of 75um or less.
  3. 3. The method for preparing the Portland cement clinker based on the marl according to claim 1, wherein in the step (2), the mass ratio of lanthanum nitrate to cerium nitrate is 5 (2-4).
  4. 4. The method for preparing Portland cement clinker based on marl according to claim 1, wherein in the step (3), the standing activation time is 2-4 hours.
  5. 5. The method for preparing the Portland cement clinker based on the marl according to claim 1, wherein in the step (4), the roasting temperature is 550-600 ℃, and the roasting time is 2-3 hours.
  6. 6. The method for preparing the Portland cement clinker based on the marl according to claim 1, wherein in the step (5), the mass ratio of the modified marl powder to the calcium carbonate is 9 (11-12).
  7. 7. The method for preparing the Portland cement clinker based on the marl according to claim 1, wherein in the step (5), the mass ratio of calcium fluoride to barium carbonate is 1 (2-4).
  8. 8. The method for preparing Portland cement clinker based on marl according to claim 1, wherein in the step (6), the calcination temperature in the first stage of mineralization and calcination is 950 ℃ and the calcination time is 45min; the second stage of mineralization calcination has a calcination temperature of 1380 ℃ and a calcination time of 30min.
  9. 9. The method for preparing Portland cement clinker based on marl according to claim 1, wherein in the step (7), the oxygen content of the oxygen-enriched air is 25% -30%.
  10. 10. Portland cement clinker based on marl, characterized in that it is prepared by the method according to any of the preceding claims 1-9.

Description

Portland cement clinker based on marl and preparation method thereof Technical Field The invention relates to the technical field of cement, in particular to a Portland cement clinker based on marl and a preparation method thereof. Background Silicate cement is used as the cementing material which is most widely applied in the field of constructional engineering, and plays a central role in various projects such as house construction, bridge roads, ocean engineering, underground tunnels and the like by virtue of the advantages of high strength, rapid setting and hardening, strong adaptability and the like. However, in sulfate erosion scenes such as marine environments, salt lake areas, underground sulfur-containing mineral deposits, sewage treatment facilities and the like, cement hydration products (such as calcium hydroxide, calcium aluminate hydrate and the like) are easy to chemically react with sulfate in the environments to generate volume expansion products such as ettringite, gypsum and the like, internal stress, structural cracking and strength reduction are caused in the set cement, and even engineering structural failure is caused when the internal stress, structural cracking and strength reduction are serious, so that the service life of engineering is greatly shortened, and the problem has become a key bottleneck for restricting the application of silicate cement in the erosion environments. In order to solve the above problems, various proposals have been made in the prior art to improve the sulfate attack resistance of cement. For example, by optimizing the composition of clinker minerals, reducing the content of tricalcium aluminate which is easy to react with sulfate, improving the proportion of tetracalcium aluminoferrite, improving the overall performance by utilizing the erosion resistance of a tetracalcium aluminate hydration product, or adding mineral admixtures such as slag, fly ash, silica fume and the like into cement, refining the pore structure of cement stone through secondary hydration reaction, reducing the permeation rate of an erosion medium, and also adopting a mode of adding chemical admixtures such as nanogel, an organic rust inhibitor and the like to block the reaction path of sulfate and hydration product. In addition, some schemes attempt to replace part of the clinker raw materials with industrial waste residues (such as steel slag and slag), and the active ingredients in the waste residues are utilized to optimize the erosion resistance while reducing the cost. However, the prior art still has a plurality of defects to be solved, firstly, the preparation of the high sulfur-resistant cement clinker depends on chemical raw materials such as high-purity calcium oxide, silicon dioxide and the like or specific industrial waste residues, the cost of the raw materials is higher, the sources are limited by regions, the marl is used as a natural mineral raw material with abundant reserves and wide distribution, the main components of the marl are calcium carbonate and clay minerals, the marl contains core elements such as silicon, aluminum, calcium and the like required by the cement clinker, but the natural mineral has compact structure, low reactivity and uneven component distribution, and when the marl is directly used for cement production, the mineral phase of the clinker is insufficiently formed, the stability is poor, and the sulfate erosion resistance is difficult to meet the requirements, so that the cheap natural resource cannot be effectively developed and utilized. Disclosure of Invention The invention aims to provide a Portland cement clinker based on marl and a preparation method thereof, which are used for solving the technical problems of the background technology. The silicate cement clinker based on the marl, which is prepared by the invention, has excellent sulfate erosion resistance. In order to achieve the above purpose, the present invention provides the following technical solutions: The preparation method of the silicate cement clinker based on the marl comprises the following steps: (1) Crushing, grinding and drying natural marl to obtain marl powder; (2) Mixing sodium hydroxide solution, lanthanum nitrate, cerium nitrate and water to prepare mixed impregnating solution; (3) Uniformly spraying the mixed impregnating solution into the marl powder, and standing for activation to obtain activated powder; (4) Drying and roasting the activated powder at low temperature, and grinding a roasting product to obtain modified shale powder; (5) Mixing the modified shale powder with calcium carbonate, quartz powder, ferric oxide, dihydrate gypsum, calcium fluoride and barium carbonate, and performing compression molding to obtain a blank; (6) Carrying out two-stage mineralization calcination on the green body; (7) And (5) preserving heat, introducing oxygen-enriched air, continuously calcining, and cooling after the calcining is finished. According to the technical