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CN-122010431-A - Method for preparing high-sulfur ferro-aluminate cement by utilizing slag iron extraction tailings

CN122010431ACN 122010431 ACN122010431 ACN 122010431ACN-122010431-A

Abstract

The invention relates to the technical field of cement materials, in particular to a method for preparing high-sulfur ferro-aluminate cement by utilizing slag iron extraction tailings, which takes the slag iron extraction tailings as a main raw material, takes carbide slag, aluminum ash and desulfurized gypsum as auxiliary materials to adjust the raw material composition, and adds a small amount of lithium slag to adjust the clinker mineral composition, the high-sulfur ferroaluminate cement clinker is prepared by a stage calcination process, and the anhydrite is added to prepare cement, so that the dependence on natural mineral resources and carbon emission in the traditional production of the ferroaluminate cement are effectively reduced, the prepared cement has excellent compressive strength, and a systematic solution is provided for the high added value utilization of the slag iron extraction tailings.

Inventors

  • WANG YALI
  • HUO BINGBING
  • CUI SUPING
  • Pei Tianrui

Assignees

  • 北京工业大学

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. The method for preparing the high-sulfur ferroaluminate cement by utilizing the slag iron extraction tailings is characterized by comprising the following steps: 1) Weighing 29-33 parts of steel slag iron extraction tailings, 17-24 parts of carbide slag, 21-27 parts of aluminum ash, 18-27 parts of desulfurized gypsum and 5-9 parts of lithium slag according to parts by weight, drying, crushing, grinding and uniformly mixing the raw materials to obtain raw materials, 2) Calcining the raw materials in stages, cooling to obtain clinker, 3) Weighing 85-89 parts of clinker by weight, uniformly mixing 11-15 parts of anhydrite by weight, and finely grinding to obtain the composite cement.
  2. 2. The method for preparing high-sulfur ferro-aluminate cement by utilizing the steel slag iron extraction tailings, which is disclosed in claim 1, wherein the steel slag iron extraction tailings comprise, by weight, 45-60% of CaO, 8-12% of total iron calculated by Fe 2 O 3 , 10-18% of Al 2 O 3 :3-7%,SiO 2 and 6-9% of MgO.
  3. 3. The method for preparing high-sulfur ferroaluminate cement by utilizing the slag iron extraction tailings according to claim 1, wherein the drying temperature in the step 1) is 100-110 ℃ and the drying time is 1-3h.
  4. 4. The method for preparing high-sulfur ferroaluminate cement by utilizing slag iron extraction tailings according to claim 1, wherein in the step 1), grinding is carried out to below 200 meshes.
  5. 5. The method for preparing high-sulfur ferroaluminate cement by using the slag iron extraction tailings according to claim 1, wherein the step 2) is performed by calcining at 1100-1200 ℃ for 30-40min and then at 1320-1350 ℃ for 20-30min.
  6. 6. The method for preparing high-sulfur ferroaluminate cement by utilizing slag iron extraction tailings according to claim 1, wherein the cooling in the step 2) adopts blast quenching.
  7. 7. The method for preparing high-sulfur ferro-aluminate cement by utilizing slag iron extraction tailings according to claim 1, wherein the main chemical components and the content of clinker in the step 2) are as follows ：CaO:40-49%,Fe 2 O 3 :3-6%,Al 2 O 3 :20-23%,SiO 2 :5-9%,SO 3 :12-16%.
  8. 8. The method for preparing high-sulfur ferro-aluminate cement by utilizing slag iron extraction tailings according to claim 1, wherein the main chemical components and contents of the anhydrite in the step 3) are 38-41% of CaO, 1-2% of SO 3 :50-54%、SiO 2 and 1-4% of MgO.
  9. 9. The method for preparing high-sulfur ferroaluminate cement by utilizing slag iron extraction tailings according to claim 1, wherein the step 3) is finely ground to a grain size less than or equal to 75 μm.
  10. 10. The cement produced by the method for producing high-sulfur ferroaluminate cement by using slag extracted iron tailings according to any one of claims 1 to 9.

Description

Method for preparing high-sulfur ferro-aluminate cement by utilizing slag iron extraction tailings Technical Field The invention relates to the technical field of cement materials, in particular to a method for preparing high-sulfur ferroaluminate cement by utilizing slag iron extraction tailings. Background The ferroaluminate cement is a special cement which is composed of anhydrous calcium sulfoaluminate (C 4A3 $), dicalcium silicate (C 2 S) and iron phases as main minerals, and has the characteristics of quick hardening, early strength, corrosion resistance and excellent freezing resistance. The traditional method for producing the ferroaluminate cement is to take limestone, aluminum/bauxite and gypsum as main raw materials and prepare and calcine the limestone, aluminum/bauxite and gypsum as main raw materials, wherein the method is seriously dependent on natural mineral resources, the aluminum/bauxite resources are increasingly deficient, the price is continuously increased, and meanwhile, the energy consumption and the carbon emission in the raw material exploitation and calcination processes are high, so that the development of the cement is restricted. In the steelmaking process, a large amount of steel slag is generated, which accounts for 15% -20% of the yield of coarse steel, and the steel slag has the problems of large fluctuation of components and phase compositions, poor stability (such as unstable volume caused by free CaO and free MgO), low gelation activity and the like, so that the comprehensive utilization rate of the steel slag is less than 30%, and besides being used for roadbed, backfill and other low-added-value applications or being used as a concrete admixture after modification, most of the steel slag is piled up for a long time, so that a large amount of land is occupied, the environment is polluted, and huge resource waste is caused. In order to reduce cost and resource consumption, the use of industrial solid waste to replace natural raw materials has become an industry trend, part of the prior art attempts to fire the aluminoferrite cement clinker by using industrial solid waste, CN117700134A discloses a red mud-based aluminoferrite cement, and after mixing high-calcium solid waste, high-silicon solid waste, high-aluminum solid waste and Bayer process red mud, the mixture is subjected to grinding, homogenization, sample preparation, calcination and cooling to prepare the red mud-based aluminoferrite cement clinker, and the red mud-based aluminoferrite cement clinker, the rest of the high-calcium solid waste, the high-aluminum solid waste and the high-sulfur solid waste are mixed and ground together to obtain the red mud-based aluminoferrite cement, but the cement mechanical strength obtained by the preparation is lower, CN118529953A discloses an aluminoferrite cement clinker, and a large amount of natural raw materials are still adopted for firing by adopting steel slag powder, bauxite, limestone, anhydrite and lithium carbonate as raw materials. The total iron content in the steel slag is 10-40%, by recycling the iron resources in the steel slag, not only can significant economic benefits be created, but also the dependence on primary iron ore can be reduced, the iron resources are extracted from the steel slag by adopting magnetic separation, carbon reduction and other processes in industry, however, the tailings after iron extraction also face the problems of stacking and low utilization rate, compared with the original steel slag, the iron content of the tailings after iron extraction is greatly reduced, and the calcium content is improved, however, the prior art lacks a systematic method for converting the tailings after iron extraction of the steel slag from 'hard solid waste' into 'iron aluminate cement raw materials' by taking the chemical composition of the tailings as a basis and through clinker design and sintering regulation. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a method for preparing high-sulfur ferroaluminate cement by utilizing slag iron extraction tailings, and in particular, the invention takes the slag iron extraction tailings as a main raw material, adds carbide slag, aluminum ash and desulfurized gypsum to adjust the raw material composition, adds a small amount of lithium slag to adjust the clinker mineral composition, prepares high-sulfur ferroaluminate cement clinker by a stage calcination process, and adds anhydrite to prepare cement, thereby not only effectively reducing the dependence of the traditional ferroaluminate cement production on natural mineral resources and carbon emission, but also ensuring that the prepared cement has excellent compressive strength and providing a systematic solution for the high-added value utilization of the slag iron extraction tailings. Specifically, the method for preparing high-sulfur ferroaluminate cement by utilizing the slag iron extraction tailings compri