A high-Belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 and its preparation method

Abstract

The present invention relates to the technology of solid waste resource utilization, and specifically relates to a high-belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 , and a preparation method thereof, belonging to the technical field of cementitious materials. The high-belite sulphoaluminate cement clinker is composed of five mineral phases: larnite (C 7 MS 4 ), Q-belite (C 2 S), calcium sulphoaluminate (C 4 A 3 $), and ferrite phase (C 4 AF). The present invention uses high-magnesium limestone with very low current utilization degree supplemented by other various industrial solid wastes, and through high-temperature calcination, turns it into a high-belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 . The C 7 MS 4 in the clinker endows the material with good carbonation activity, and the Q phase endows the material with excellent early mechanical properties. The present invention not only effectively utilizes a large amount of industrial solid wastes and high-magnesium limestone, but also the produced high-belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 has excellent mechanical properties and durability, good production economic benefits, and great market potential, and has important significance.

Description

Technical Field

[0001] The present invention relates to the technology of solid waste resource utilization, and particularly relates to a high belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 and its preparation method, belonging to the technical field of cementitious materials. Background Technique

[0002] In recent years, with the continuous development of the cement industry, the consumption of high-quality limestone has been increasing, its reserves have gradually decreased, and the low-grade of limestone is expected to become normal, with high-magnesium limestone being the most widespread. At the same time, during the process of human industrial production, a large amount of industrial solid waste residues are generated. The increasing amount of these residues directly endangers the property and human life safety near the slag yard, poses a serious threat to the environment and resources, and is difficult to be effectively utilized.

[0003] High belite sulphoaluminate cement (HB$AC) is a new type of low-calcium cement with C 2 S and C 4 A 3 $ as the main mineral phases, and it has excellent mechanical and durability properties. Compared with traditional Portland cement, the calcination of this low-calcium cement has a lower requirement for the grade of calcareous raw materials. Therefore, in terms of composition, low-grade high-magnesium limestone can be used to produce HB$AC. The disadvantage is that high-magnesium limestone brings in excessive MgO during the clinker firing process, which is likely to cause poor volume stability of the cement stone. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the present invention provides a high belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 , and this system can efficiently utilize various solid waste residues and high-magnesium limestone to produce clinker, can consume the stock of high-magnesium limestone, and promote the resource utilization of high-magnesium limestone and the functional utilization of MgO.

[0005] The present invention also provides a preparation method of a high belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 . This method has a simple technological process, can consume a large amount of solid waste residues, and can carry out industrial production of solid waste resource utilization.

[0006] The technical solution adopted by the present invention to achieve the above purpose is as follows:

[0007] The present invention provides a high belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 , and this high belite sulphoaluminate cement clinker is composed of larnite (C 7 MS 4 ) - Q - belite (C 2(S)-calcium sulfoaluminate (C 4 A 3 (S)-ferrite phase (C 4 AF) and consists of five mineral phases.

[0008] Preferably, the percentage of the mineral phase composition of the cement clinker is: C 7 MS 4 : 5 - 10%, Q phase: 10 - 20%, C 2 S: 45 - 60%, C 4 A 3 $: 10 - 25%, C 4 AF: 5 - 10%.

[0009] The percentage of the raw material oxide composition of the cement clinker provided by the present invention is: CaO: 42 - 67%, SO 3 : 1 - 4%, SiO 2 : 18 - 26%, Al 2 O 3 : 10 - 25%, Fe 2 O 3 : 1 - 4%, MgO: 2 - 5%.

[0010] Preferably, the percentage of the low - grade / non - traditional raw material composition of the raw material of the cement clinker is: desulfurized gypsum: 2 - 5%, high - magnesium limestone: 60 - 72%, medium - low - grade bauxite: 11 - 18%, steel slag tail mud: 1 - 4%, antimony slag: 10 - 17%.

[0011] The present invention also provides a preparation method of the above - mentioned high - belite sulphoaluminate cement clinker containing Q phase and C 7 MS 4 , which includes the following steps:

[0012] a) Grinding and uniformly mixing the raw materials according to the formula to obtain powdered cement raw material;

[0013] b) Pressing and drying the powdered cement raw material, then calcining, taking it out and quenching rapidly after keeping warm for a period of time, grinding and sieving to obtain the high - belite sulphoaluminate cement containing Q phase and C 7 MS 4 .

[0014] Preferably, in step b), the heat preservation is carried out at 1300 - 1350 °C for 30 - 90 min.

[0015] The present invention aims to prepare high - belite sulphoaluminate cement containing Q phase and C 7 MS 4 by using multiple solid wastes and high - magnesium limestone, which can not only protect the environment but also generate benefits, and has great potential.

[0016] The beneficial effects of the present invention are as follows: The present invention uses high-magnesium limestone with a very low current utilization rate supplemented by other various industrial solid wastes and turns them into a high-belite sulphoaluminate cement clinker containing Q-phase and C 7 MS 4 by high-temperature calcination. The C 7 MS 4 in the clinker endows the material with good carbonation activity, and the Q-phase endows the material with excellent early mechanical properties. The present invention not only effectively utilizes a large amount of industrial solid wastes and high-magnesium limestone, but also the produced high-belite sulphoaluminate cement clinker containing Q-phase and C 7 MS 4 has excellent mechanical properties and durability, good production economic benefits, great market potential, and is of great significance. Specific Embodiments

[0017] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments.

[0018] The experimental raw materials used in the present invention are desulfurized gypsum, high-magnesium limestone, medium- and low-grade bauxite, steel slag tailings: 1-4, and antimony slag. The compositions of the raw materials used in Examples 1-3 are shown in Table 1.

[0019] Table 1 Chemical Compositions of Experimental Raw Materials

[0020]

[0021] Example

[0022] A high-belite sulphoaluminate cement clinker containing Q-phase and C 7 MS 4 has the following percentage of mineral composition: C 7 MS 4 : 10%, Q-phase: 10%, C 2 S: 45%, C 4 A 3 $: 25%, C 4 AF: 10%.

[0023] The specific preparation method is as follows:

[0024] Weigh the raw materials according to the mineral composition, grind the raw materials, mix them evenly to obtain powdered cement raw meal, press the raw meal into circular cake specimens with a size of φ60mm×10mm, dry them, then calcine them in a high-temperature furnace, take them out and cool them rapidly after holding at 1300°C for 60 minutes, and knock them into small pieces with a hammer to obtain cement clinker.

[0025] Example

[0026] A high-belite sulphoaluminate cement clinker containing Q-phase and C 7 MS4 The composition percentage of high belite sulphoaluminate cement clinker minerals is: 7 MS 4 :7%, Q phase: 12%, C 2 S: 60%, C 4 A 3 $:15%, C 4 AF: 6%.

[0027] The specific preparation method is as follows:

[0028] The raw materials are weighed and calculated according to the mineral composition, ground and mixed evenly to obtain powdered cement raw material, which is pressed into round cake specimens with a size of φ60mm×10mm, dried, and then calcined in a high-temperature furnace. After being kept at 1330℃ for 60min, the raw materials are taken out and quenched, and then hammered into small pieces with a hammer to obtain cement clinker.

[0029] Example

[0030] A phase containing Q and C 7 MS 4 The composition percentage of high belite sulphoaluminate cement clinker minerals is: 7 MS 4 :5%, Q phase: 20%, C 2 S: 55%, C 4 A 3 $: 15%, C 4 AF: 5%.

[0031] The specific preparation method is as follows:

[0032] The raw materials are weighed and calculated according to the mineral composition, ground and mixed evenly to obtain powdered cement raw material, which is pressed into round cake specimens with a size of φ60mm×10mm, dried, and then calcined in a high-temperature furnace. After 90 minutes at 1350℃, the raw materials are taken out and quenched, and then hammered into small pieces to obtain cement clinker.

[0033] Example

[0034] The above-obtained clinker and appropriate amount of steel balls were placed in a ball mill, fully ground on a planetary ball mill to a certain fineness, passed through a 200-mesh sieve, and the residue on the sieve was controlled at 0.2%-5%. According to the water-cement ratio of 0.3-0.35, cement slurry was prepared using a cement slurry mixer. A 2×2×2cm 3 The mold was formed and the samples were cured in a room at room temperature for 24 hours before demolding. Then, the samples prepared in each embodiment were placed in a curing box and cured for 3 days, 7 days, and 28 days under standard conditions of constant temperature and humidity. The compressive strength tests were performed respectively. The specific results are shown in Table 2.

[0035] Table 2 Mechanical properties of the specimens in the examples at different ages

[0036]

Claims

1. A high-belite sulphoaluminate cement clinker containing Q phase and C7MS4, characterized in that: The high-belite sulphoaluminate cement clinker is composed of five mineral phases: calcite (C7MS4)-Q-belite (C2S)-calcium sulphoaluminate-iron phase (C4AF); The mineral phase composition percentage of the cement clinker is: C7MS4: 5-10%, Q phase: 10-20%, C2S: 45-60%, calcium sulfoaluminate: 10-25%, C4AF: 5-10%; The raw material oxide composition percentage of the cement clinker is: CaO: 42-67%, SO3: 1-4%, SiO2: 18-26%, Al2O3: 10-25%, Fe2O3: 1-4%, MgO: 2-5%; The raw materials of the cement clinker are composed of low-grade / non-traditional raw materials in the following percentages: desulfurized gypsum: 2-5%, high-magnesium limestone: 60-72%, medium-low-grade bauxite: 11-18%, steel slag tailings: 1-4%, and antimony slag: 10-17%.

2. A method for preparing high-belite sulphoaluminate cement clinker containing Q phase and C7MS4 as claimed in claim 1, characterized in that: The following steps are included: a) Grinding the raw materials according to the formula and mixing them evenly to obtain powdered cement raw meal; b) The powdered cement raw material is tableted, dried, calcined, kept warm for a period of time, taken out and rapidly cooled, ground and sieved to obtain high-belite sulphoaluminate cement clinker containing Q phase and C7MS4.

3. The preparation method according to claim 2, characterized in that: In step b), the heat preservation is carried out at 1300-1350° C. for 30-90 min.

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