Search

CN-121999894-A - Solid waste base C2S−C3S2−C4A3Ŝ energy-saving low-carbon cement preparation method

CN121999894ACN 121999894 ACN121999894 ACN 121999894ACN-121999894-A

Abstract

The invention discloses a solid waste base C 2 S C 3 S 2 C 4 A 3 The energy-saving low-carbon cement preparing process includes preparing raw material, calculating raw material, homogenizing and calcining corresponding raw material based on the mixing proportion to obtain clinker, and based on C in each gram of clinker 4 A 3 Determining the mixing amount of gypsum based on the mass of SO 3 in each gram of gypsum, and mixing and grinding corresponding gypsum and clinker to obtain C 2 S C 3 S 2 C 4 A 3 And (3) cement. The invention optimizes the specific surface area and the mineral quality composition range based on hydration heat, mechanical strength and CO 2 absorption capacity, provides a preparation theory of solid waste base CSSAC cement, and can provide a new idea for producing novel energy-saving, low-carbon and environment-friendly cement in the cement industry.

Inventors

  • Xie Gangchuan
  • WU YONGQI
  • GONG JINGWEI
  • JIN QIANG
  • WANG HUI
  • LI JIANLIN
  • Tang Gezhou
  • Su Zhejun
  • ZHU YING
  • CUI YIBIN

Assignees

  • 新疆农业大学
  • 新疆天山水泥有限责任公司

Dates

Publication Date
20260508
Application Date
20260121

Claims (10)

  1. 1. Solid waste base C 2 S C 3 S 2 C 4 A 3 The method for preparing the energy-saving low-carbon cement is characterized by comprising the following steps of: preparing raw materials including carbide slag, silica fume, bauxite and gypsum; Raw material calculation was performed to give a liquid phase viscosity coefficient LPV of 2.50 In the region of 3.87, the ratio SSC of the amount of SiO 2 to the sum of the amounts of SiO 2 and CaO is 0.33 Determining an oxide content range and a mineral composition range according to the LPV value and the SSC value of the liquid phase viscosity coefficient in a 0.37 interval range, and further determining raw material consumption to obtain a mixing ratio; homogenizing and calcining the corresponding raw materials based on the mixing ratio to obtain clinker; based on C in clinker per gram 4 A 3 Determining the gypsum doping amount by the mass of SO 3 in each gram of gypsum; based on the mixing amount of the gypsum, corresponding gypsum and clinker are mixed and ground to obtain C 2 S C 3 S 2 C 4 A 3 And (3) cement.
  2. 2. The method of claim 1, wherein the calculated expression for the liquid phase viscosity coefficient LPV value is: ; Wherein the method comprises the steps of Represents the ratio of the sum of the mass of the oxide having an increased liquid phase viscosity to the sum of the mass of the oxide having a decreased liquid phase viscosity, p, q, x and y are each the number of corresponding atoms, Representing the mass fraction.
  3. 3. The method of claim 1, wherein the oxide content range comprises 59.65% 61.13% CaO、36.47% 37.68% SiO 2 、4.16% 8.79% Al 2 O 3 、2.18% 4.61% SO 3 , a mineral composition range including 37.19% 55.53% C 2 S、14.74% 19.77% C 2 AS、15.73% 25.03% C 3 S 2 、3.05% 5.55% CS、0.87% 1.66% C 4 A 3 。
  4. 4. The method according to claim 1, characterized in that the specific method for determining the raw material composition, resulting in the compounding ratio, comprises the steps of: Correcting the mass fraction of SO 3 to obtain the corrected mass fraction of SO 3 , wherein the expression is as follows: ; Wherein the method comprises the steps of For the mass fraction of corrected SO 3 ,%; mass percent of SO 3 originally designed; Firing the maximum C in the clinker for the initial SO 3 mass 4 A 3 Mass fraction,%; the mixing ratio of silica fume, carbide slag, bauxite and gypsum is calculated, and the expression is as follows: ; Wherein a 11 、a 12 、a 13 、a 14 represents the mass percent of CaO in the silica fume, the carbide slag, the bauxite and the gypsum respectively,%, "a 21 、a 22 、a 23 、a 24 represents the mass percent of SiO 2 in the silica fume, the carbide slag, the bauxite and the gypsum respectively,%," a 31 、a 32 、a 33 、a 34 represents the mass percent of Al 2 O 3 in the silica fume, the carbide slag, the bauxite and the gypsum respectively,%, "a 41 、a 42 、a 43 、a 44 represents the mass percent of SO 3 in the silica fume, the carbide slag, the bauxite and the gypsum respectively,%," x 1 、x 2 、x 3 、x 4 represents the mass percent of the silica fume, the carbide slag, the bauxite and the gypsum respectively,%; for designing the mass fraction,%; The molar mass ratio of CaO to SiO 2 is designed; For the design of the mass fraction of Al 2 O 3 ,%.
  5. 5. The method according to claim 1, wherein the homogenized and calcined raw material is a raw material baked to constant weight, wherein carbide slag, bauxite, gypsum are ground to 75 μm square mesh screen and silica fume is ground to 75 150 μm。
  6. 6. The method according to claim 5, characterized in that homogenization is carried out for 30 minutes, after which the homogenized raw meal is placed in a silicon carbide crucible and vibrated to a stabilization plane.
  7. 7. The method according to claim 1, wherein the calcination regime of the raw meal is such that when the free CaO content is 0.15% or less, the raw meal is heated from 50 ℃ to 900 ℃ at a rate of 5 ℃ per minute, heated to 1200 ℃ at 3 ℃ per minute after 30 min ℃, and finally heated to 1250 ℃ at 5 ℃ per minute and heated to 1h, and the melt used for calcination is required to be rapidly cooled to room temperature at 245 ℃ per minute to produce clinker.
  8. 8. The method of claim 1, wherein the calculated expression of the gypsum doping amount is: ; Wherein the method comprises the steps of For every gram C 4 A 3 Corresponding gypsum mixing amount, g; for C in each gram of clinker 4 A 3 G, mass of (a); g is the mass of SO 3 per gram of gypsum.
  9. 9. The method of claim 1, wherein the gypsum is mixed with clinker to be ground by grinding the mixture to a 45 μm square mesh screen.
  10. 10. The method according to claim 2, wherein when the liquid phase viscosity coefficient LPV value exceeds a preset range, the liquid phase viscosity coefficient LPV value is brought into conformity with the preset range by adding iron powder, wherein the iron powder mass is calculated by the following formula: ; Wherein IM represents the iron ratio,% (Al 2 O 3 ) represents the mass fraction of design Al 2 O 3 ,% (Fe 2 O 3 ) represents the mass fraction of design Fe 2 O 3 .

Description

Method for preparing solid waste based C 2S−C3S2−C4A3 Ŝ energy-saving low-carbon cement Technical Field The invention relates to the technical field of cement, in particular to a solid waste base C 2 SC3S2C4A3A method for preparing energy-saving low-carbon cement. Background Carbon emissions from the cement industry account for 7% of global carbon emissions8%, It has become the primary battlefield for carbon abatement. The carbon emissions of the cement industry mainly originate from the decomposition of CaCO 3 (50%60 Percent, combustion of fuel (40 percent) and power consumption (5 percent)10%) Of which the power consumption mainly derives from the grinding of the raw materials and cement and the cooling of the clinker. Prior studies have found that the production of a silicate containing tricalcium silicate (C 3S2) and dicalcium silicate (C 2 S, including betaC 2 S and gammaC 2 S) can be reduced by 15%33% CO 2 emissions, which is mainly due to the low calcium, low temperature requirements and self-pulverization characteristics of C 3S2 and C 2 S. Therefore, the use of calcareous, alumino-silicate fully solid waste materials to replace limestone, clay and sandstone to produce low-calcium silicate cements has become a research hotspot in order to achieve multiple effects of energy conservation, emission reduction and sustainability. Unfortunately, these low-calcium silicate minerals (e.g., beta-C 2S、γ-C2S、C3S2, CS) are low-active and non-hydratable, and although CO 2 mineralization can excite the reactivity of these calcium silicate minerals and promote early strength, it is limited by low water to gel ratio (0.10.2 If in a high water to gel ratio (0.4) environment, the early (< 2 d) strength improvement of the calcium silicate mineral by CO 2 mineralization is not very significant. Of interest is calcium sulfoaluminate (Ye' elinite, C 4A3) Has the characteristics of high hydration activity, rapid early strength development and the like, and is a core mineral of sulphoaluminate cement (SAC) and high belite-sulphoaluminate cement. Thus, reconstruct C 2S、C3S2 and C 4A3Preparation of the main component, C, of calcium silicate minerals 4A3The method creates a new opportunity for the preparation of the auxiliary solid waste-based calcium silicate-calcium sulfoaluminate cement for realizing energy saving, low carbon, strength and sustainable multiple lifting. In recent years, calcium silicate minerals and C 4A3The study of reconstitution to produce low carbon cements was performed in an unlimited number of ways, of which the most typical are high belite-calcium sulfoaluminate cements (HBSAC) and alite-calcium sulfoaluminate cements. Huang and Li et al 1100 using phosphogypsum and aluminum-rich mud as industrial by-products1150 ℃ Heat preservation 3060 The successful preparation of HBSAC in min shows that P 2O5 and F impurities in phosphogypsum can promote C 4A3And C 2 S mineral formation, but inhibits C 4A3Hydration and strength development of (c). The scholars also adopt carbide slag, silica fume, fly ash, desulfurized petroleum coke slag, red mud, electrolytic manganese slag, barium slag and other bulk solid wastes in 12001300 ℃ Heat preservation 3060 Making HBSAC min, and C 2S、C4A3And C 4 AF content of 40.01%56.60%、22.30%37.25%、1.58%At 11.60%, the compressive strength of 28 d can reach 36.060.0 And (5) MPa. Gao et al prepared HBSAC clinker by using Bayer process red mud, blast furnace slag, steel slag, flue gas desulfurization slag and carbide slag total solid waste as raw materials at 1300 ℃ and 60 min 2S、C4A3The mass fractions of C 4 AF and dodecacalcium heptaluminate (C 12A7) were 60.0%, 10.0%, 9.0% and 21.0%, respectively, and the compressive strength of cement 28 d was only 29.3 MPa. Obviously, the early strength and C of HBSAC cements 4A3In positive correlation with the content of C 12A7, which is mainly attributed to C 4A3And rapid hydration of C 12A7. Also, the scholars prepared a mixture of C 3S(41.6%)、C2S(26.9%)、C3A(7.1%)、C2(AF)O5 (3.7%) and C by heat preservation at 1300 ℃ of 60 min by using phosphorus slag, copper slag and fly ash as partial raw materials 4A3(1.3%) Predominantly C 3S- C4A3Clinker, cuO and P 2O5 in copper and phosphorus slag were found to promote C 3 S and C 4A3The coexistence of phases, clinker hydration 28 d, achieved a compressive strength of about 61.25 MPa. Obviously, even C 3 S and C 4A3Coexisting but C 4A3Is of little quality, which the authors believe is C 4A3Is suppressed from increasing in the formation iron receiving rate (IM). Ma et al for fired C 3S- C4A3C coexisting with C 3 S after the clinker is subjected to the secondary heat treatment at 1250 DEG C 4A3Mass compared with C before secondary heat treatment 4A3The mass (0.8%) was raised to 3.6%, which is believed to be due to the acceleration of the reaction of the following formula: 。 In addition, cho et al has recently prepared low-calcium silicate cement with C 3S(5.8%)、C2S(25.5%)、C3S2 (16.6%) and CS (29.2%) coexist