阅读说明：本技术 一种高抗蚀硅酸盐水泥的制备方法 (Preparation method of high corrosion-resistant portland cement ) 是由 陈敬 马树立 王九龙 张宇 王营和 王玉和 王海雨 李竹勤 于 2019-10-15 设计创作，主要内容包括：本发明提供一种高抗蚀硅酸盐水泥的制备方法,属于无机材料技术领域,将硅酸盐水泥熟料、粉煤灰、胶凝材料、石膏经单独研磨后混合或共同混合后研磨,获得高抗蚀硅酸盐水泥,其中,所用硅酸盐水泥熟料的制备方法为：将粘土质原料、钙质原材料和铁质原料烘干,混合,研磨,获得生料；烧结生料和矿化剂,冷却,获得硅酸盐水泥熟料；其中,在烧结之前或烧结过程中将包含珍珠岩和三氧化二锑的矿化剂加入到生料粉末中。本发明硅酸盐水泥熟料的制备方法能够提高硅酸盐水泥熟料的易烧性,增加熟料的结晶度,改善熟料在不同龄期的抗折和抗压强度；本发明制得的高抗蚀硅酸盐水泥具有良好的工作性能、较高的抗压强度和较高的抗侵蚀性能,耐久性能良好。(The invention provides a preparation method of high corrosion resistant portland cement, belonging to the technical field of inorganic materials, and the preparation method comprises the following steps of grinding portland cement clinker, fly ash, cementing material and gypsum separately or jointly, and then grinding the mixture to obtain the high corrosion resistant portland cement, wherein the preparation method of the used portland cement clinker comprises the following steps: drying, mixing and grinding the clay raw material, the calcium raw material and the iron raw material to obtain a raw material; sintering the raw material and the mineralizer, and cooling to obtain portland cement clinker; wherein a mineralising agent comprising perlite and antimony trioxide is added to the raw meal powder before or during sintering. The preparation method of the portland cement clinker can improve the easy burning property of the portland cement clinker, increase the crystallinity of the clinker and improve the bending strength and the compressive strength of the clinker at different ages; the high corrosion resistant Portland cement prepared by the invention has good working performance, higher compressive strength, higher corrosion resistance and good durability.)

1. A preparation method of portland cement clinker is characterized by comprising the following steps:

-raw material preparation, drying, mixing and grinding the clayey raw material, the calcareous raw material and the iron raw material to obtain raw material;

-clinker firing, sintering the raw meal and mineralizer, cooling to obtain portland cement clinker;

wherein a mineralising agent comprising perlite and antimony trioxide is added to the green powder before or during sintering.

2. The method for manufacturing portland cement clinker according to claim 1, wherein: the calcareous raw material is selected from one or more of quicklime, limestone, industrial by-products with high CaO content and waste.

3. The method for manufacturing portland cement clinker according to claim 1, wherein: the ferrous material is selected from iron ore, iron-containing material, and high Fe₂O₃The content of one or more of industrial by-products and wastes.

4. The method for manufacturing portland cement clinker according to claim 1, wherein: the sintering temperature is 1200-1400 ℃, the heat preservation time at the sintering temperature is 20-120min, and the cooling is rapid cooling.

5. The method for manufacturing portland cement clinker according to claim 1, wherein: the batch ratio value of the raw material is as follows: the lime saturation coefficient (KH) is 0.9-1.0, the silicon ratio (SM) is 2.0-3.0, and the aluminum ratio (IM) is 0.5-2.0.

6. Portland cement clinker obtained by the process according to any one of claims 1 to 5.

7. The portland cement clinker of claim 6, wherein: the main component of the portland cement clinker comprises C₃S、C₂S、C₃A、C₄AF of composition C in parts by weight₃S 50.7-56％、C₂S 20.2-25.4％、C₃A 8.5-12.3％、C₄AF 10.0-15.2％。

8. The portland cement clinker of claim 6, wherein: the strength of the portland cement clinker at each age exceeds the requirement of 52.5 standards.

9. A preparation method of high corrosion-resistant portland cement is characterized by comprising the following steps: the portland cement clinker of claim 6, 7 or 8, fly ash, cement and gypsum are ground separately or together to obtain high corrosion resistance portland cement.

10. The method for preparing high corrosion resistant portland cement according to claim 9, wherein: the high corrosion resistant Portland cement comprises the following components in percentage by weight: 50-80% of portland cement clinker, 6-14% of fly ash, 12-30% of cementing material and 4-6% of gypsum.

Technical Field

The invention belongs to the technical field of inorganic materials, and particularly relates to a preparation method of high-corrosion-resistance portland cement.

Background

The definition of the general portland cement in the current national standard GB 175-2007 general portland cement is as follows: the hydraulic cementing material is prepared by silicate cement clinker, a proper amount of gypsum and specified mixed materials. Portland cement is mainly composed of C₃S、 C₂S、C₃A and C₄The AF mineral composition, the sum of the four generally exceeding 95% of the total weight, in particular the first two silicate minerals, generally exceeding 75%. Portland cement and ordinary Portland cement, composite cement and the like derived from the Portland cement are one of the most important building materials with the largest use amount at present, are widely applied due to the advantages of high compressive strength, strong adaptability, low price and the like, and the application of concrete and reinforced concrete taking the Portland cement as a cementing material is increased day by day, so that the Portland cement is widely applied to basic construction of industry, agriculture, national defense, water conservancy, traffic, cities and the like to produce various concrete and other products. But the corrosion resistance of the cement material is poor due to the material composition and the internal pore structure of the cement. Accidents such as premature failure and collapse damage occur due to poor durability, and cause significant losses.

With the development of science and technology, the progress of society and the shortage of resources, the land environment is more and more difficult to meet the requirements of human development, and the ocean becomes a new development target as a wide resource. However, the particularity of the marine environment determines that the construction of marine engineering is necessarily subject to severe examination. In the marine environment, the durability problem of the cement-based material is very outstanding, and the service life of the marine structure is seriously influenced. The concentration of chloride ions in seawater is about 19g/L, the concentration of sulfate radicals is about 2.2g/L, which is much higher than the concentration of magnesium ions (about 0.8g/L) and aggressive carbon dioxide (about 0.04g/L), i.e. the aggressive media in seawater are mainly chloride ions and sulfate ions. Chloride ions easily pass through the interior of the cement-based material and migrate to the surface of the steel bar to cause corrosion, so that the bond stress of the steel bar is reduced, and the structure is failed; the sulfate attack is the cracking of cement-based materials due to the formation of expansive products such as ettringite, gypsum, etc. The sulfate attack process is inhibited in the presence of chloride ions, which are a major factor affecting the durability of cement-based materials in marine environments. Therefore, the improvement of the seawater erosion resistance, especially the chloride ion erosion resistance, of the Portland cement is an important method for solving the problem of poor durability of Portland cement-based materials in marine environments.

Disclosure of Invention

The invention aims to provide a method for preparing portland cement clinker, which can reduce the content of free CaO in the clinker, improve the burning easiness of the portland cement clinker, increase the crystallinity of the clinker and improve the bending strength and the compressive strength of the clinker in different ages, and the obtained portland cement clinker has the strength exceeding the requirement of the 52.5 standard in each age and has good corrosion resistance.

The technical scheme adopted by the invention for realizing the purpose is as follows: a preparation method of portland cement clinker comprises the following steps:

-raw material preparation, drying, mixing and grinding the clayey raw material, the calcareous raw material and the iron raw material to obtain raw material;

-clinker firing, sintering the raw meal and mineralizer, cooling to obtain portland cement clinker;

wherein a mineralising agent comprising perlite and antimony trioxide is added to the raw meal powder before or during sintering.

The invention uses the mineralizer, which can remarkably reduce the melting temperature and the liquid phase viscosity of the raw meal powder in the clinker sintering process, so that the temperature of the liquid phase is advanced, thereby being beneficial to the formation of the clinker and increasing the conversion rate of the clinker; moreover, the content of free state CaO (f-CaO) in the clinker can be reduced, and the easy burning property of the portland cement clinker is improved. In addition, the main mineral composition of the clinker is not influenced by the mineralizer, but the mineralizer is more beneficial to the development and crystallization of the clinker, can increase the crystallinity of the clinker, weaken the later strength reduction degree in the aluminate cement, improve the bending strength and the compressive strength of the clinker at different ages, and also can improve the corrosion resistance of the silicate cement clinker.

According to an embodiment of the present invention, the calcareous raw material is selected from one or more of quicklime, limestone, industrial by-products and wastes having a high CaO content.

According to an embodiment of the invention, the ferrous material is selected from iron ore, iron-containing material, with high Fe₂O₃The content of one or more of industrial by-products and wastes.

According to one embodiment of the invention, the sintering temperature is 1200-1400 ℃, the holding time at the sintering temperature is 20-120min, and the cooling is rapid cooling.

According to one embodiment of the invention, the batch rate values of the raw meal are: the lime saturation coefficient (KH) is 0.9-1.0, the silicon ratio (SM) is 2.0-3.0, and the aluminum ratio (IM) is 0.5-2.0.

It is a further object of the present invention to provide a portland cement clinker obtained by the above method.

According to an embodiment of the invention, the main component of the portland cement clinker comprises C₃S、C₂S、C₃A、C₄AF of composition C in parts by weight₃S 50.7-56％、C₂S 20.2-25.4％、C₃A 8.5-12.3％、C₄AF 10.0-15.2％。

According to one embodiment of the invention, the strength of the portland cement clinker at each age exceeds the requirements of the 52.5 standard.

The present invention also provides a method for preparing high corrosion resistance portland cement, which comprises grinding portland cement clinker, fly ash, a cementing material, and gypsum separately or together, and then mixing and grinding the mixture to obtain high corrosion resistance portland cement with good working performance, high compressive strength, high corrosion resistance, and good durability.

Preferably, the cementing material is nano silicon dioxide, nano aluminum oxide, nano calcium carbonate, silica fume, micro silicon powder, silicon aluminum calcium sodiumMore preferably, the rice particles are more than one of the rice particles. The cementing material can participate in hydration reaction to generate a cementing substance, improves the strength of a cement system, can fully play the physical filling role, reduces the porosity of the cement system, improves the density, and is favorable for inhibiting the migration of harmful ions and promoting the solidification of the harmful ions. The gypsum has good retarding and reinforcing effects, under the condition of the presence of the gypsum, the gypsum is consumed through hydration reaction to generate AFt, and the micro-expansion is generated, so that the strength of the cement can be improved, the porosity can be reduced, the density of a cement system is improved, and harmful substances in the external environment are effectively prevented from entering the inside of the cement concrete. The fly ash has the volcanic ash activity, the microscopic form of the fly ash is glass beads, the fly ash can play a role in lubricating through the ball effect, and the working performance of the cement concrete is improved. Has good cohesiveness, water retention and working performance. The high corrosion-resistant portland cement has good working performance, higher compressive strength, higher corrosion resistance and good durability, the strength of the high corrosion-resistant portland cement exceeds the requirement of a 52.5 standard when the high corrosion-resistant portland cement is maintained for 28 days, the sulfate corrosion resistance coefficient is 1.3-1.4, and the chloride ion diffusion coefficient is 0.3-0.5 multiplied by 10^-12m²And/s meet the index requirements of national standards of GB/T31289-2014-maritime work Portland cement. In conclusion, the high corrosion resistant Portland cement has better comprehensive performance and can be used for marine buildings with severe marine conditions and long design service life.

According to one embodiment of the invention, the high corrosion resistant portland cement comprises the following components in percentage by weight: 50-80% of portland cement clinker, 6-14% of fly ash, 12-30% of cementing material and 4-6% of gypsum.

Compared with the prior art, the invention has the beneficial effects that: the silicate cement clinker has low content of free CaO (f-CaO) in the silicate cement clinker, high crystallinity, strength of each age period exceeding the requirement of 52.5 standards and good corrosion resistance; the high corrosion-resistant portland cement prepared by the preparation method has good working performance, higher compressive strength, higher corrosion resistance and good durability, and the strength of the high corrosion-resistant portland cement exceeds 52.5 standard when the high corrosion-resistant portland cement is maintained for 28 daysThe standard requirement is that the sulfate erosion resistance coefficient is 1.3-1.4, and the chloride ion diffusion coefficient is 0.3-0.5 multiplied by 10^-12m²And/s meet the index requirements of national standards of GB/T31289-2014-maritime work Portland cement. The high corrosion resistant Portland cement has better comprehensive performance and can be used for marine buildings with severe marine conditions and long design service life.

The technical scheme provided by the invention is adopted to provide the preparation method of the high corrosion resistance portland cement, which makes up the defects of the prior art, and has the advantages of reasonable design and convenient operation.

Drawings

FIG. 1 is an X-ray diffraction pattern of the mineral composition of a silicate cement clinker in test example 1 of the present invention;

FIG. 2 is a histogram of the results of the sulfate erosion resistance test of the highly corrosion-resistant portland cement in test example 2 according to the present invention;

FIG. 3 is a histogram showing the results of the chloride ion diffusion coefficient test of the highly corrosion-resistant portland cement of test example 2 according to the present invention.

Detailed Description

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It is not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

These examples are provided only for more specifically illustrating the present invention, and it is apparent to those skilled in the art that the scope of the present invention is not limited to these examples according to the gist of the present invention.

One embodiment of the present invention provides a method for preparing portland cement clinker, comprising the steps of:

-raw material preparation, drying, mixing and grinding the clayey raw material, the calcareous raw material and the iron raw material to obtain raw material;

-clinker firing, sintering the raw meal and mineralizer, cooling to obtain portland cement clinker;

wherein a mineralising agent comprising perlite and antimony trioxide is added to the raw meal powder before or during sintering.

The weight ratio of perlite to antimony trioxide in the mineralizer is 1:0.02-0.1, and the mineralizer is added into a clayey raw material, a calcareous raw material and an iron raw material, so that the temperature of a liquid phase can be advanced by remarkably reducing the melting temperature and the viscosity of the liquid phase of raw material powder in the clinker firing process, the clinker can be formed easily, and the conversion rate of the clinker can be increased; moreover, the content of free state CaO (f-CaO) in the clinker can be reduced, the content of the f-CaO is less than 0.1 percent, namely, the CaO in the clinker exists almost completely in a mineral form, and the easy burning property of the portland cement clinker is improved. In addition, the main mineral composition of the clinker is not influenced by the mineralizer, but the mineralizer is more beneficial to the development and crystallization of the clinker, can increase the crystallinity of the clinker, weaken the later strength reduction degree in the aluminate cement, improve the bending strength and the compressive strength of the clinker at different ages, and also can improve the corrosion resistance of the silicate cement clinker.

In one embodiment of the invention, the calcareous raw material is selected from one or a mixture of lime, limestone, industrial by-products and wastes with a high CaO content. More preferably, the calcareous raw material is selected from limestone.

In one embodiment of the invention, the ferrous material is selected from iron ore, ferrous materials, having a high Fe content₂O₃The content of one or more of industrial by-products and wastes. More preferably, the ferrous feed material is selected from iron ore.

In one embodiment of the present invention, the sintering temperature is 1200-1400 ℃, such as 1225 ℃, 1250 ℃, 1270 ℃, 1300 ℃, 1320 ℃, 1350 ℃, 1370 ℃, 1380 ℃ and the like, the heat preservation time at the sintering temperature is 20-120min, such as 25min, 30min, 40min, 45min, 50min, 60min, 70min, 75min, 80min, 93min, 100min, 115min and the like, and the cooling is a rapid cooling.

In one embodiment of the present invention, the batch rate values of the raw meal are: the lime saturation coefficient (KH) is 0.9-1.0, the silicon ratio (SM) is 2.0-3.0, and the aluminum ratio (IM) is 0.5-2.0.

An embodiment of the present invention provides a portland cement clinker obtained by the above method.

In one embodiment of the present invention, the Portland cement clinker comprises C as a main component₃S、C₂S、C₃A、C₄AF of composition C in parts by weight₃S 50.7-56％、C₂S 20.2-25.4％、C₃A 8.5-12.3％、C₄AF 10.0-15.2％。

In one embodiment of the present invention, the strength of portland cement clinker at each age exceeds the 52.5 standard requirement.

An embodiment of the present invention provides a method for preparing high corrosion resistant portland cement, comprising grinding the portland cement clinker of claim 5 or 6, fly ash, a cementitious material, and gypsum individually or together, and then mixing and grinding to obtain the high corrosion resistant portland cement.

In an embodiment of the present invention, the gelling material is one or more of nano silica, nano alumina, nano calcium carbonate, silica fume, and micro silica fume, silica. The cementing material can participate in hydration reaction to generate a cementing substance, improves the strength of a cement system, can fully play the physical filling role, reduces the porosity of the cement system, improves the density, and is favorable for inhibiting the migration of harmful ions and promoting the solidification of the harmful ions. The gypsum has good retarding and reinforcing effects, under the condition of the presence of the gypsum, the gypsum is consumed through hydration reaction to generate AFt, and the micro-expansion is generated, so that the strength of the cement can be improved, the porosity can be reduced, the density of a cement system is improved, and harmful substances in the external environment are effectively prevented from entering the inside of the cement concrete. The fly ash has the volcanic ash activity, the microscopic form of the fly ash is glass beads, the fly ash can play a role in lubricating through the ball effect, and the working performance of the cement concrete is improved. Has good cohesiveness, water retention and working performance. The high corrosion-resistant portland cement has good working performance, higher compressive strength, higher corrosion resistance and good durability, the strength of the high corrosion-resistant portland cement exceeds the requirement of a 52.5 standard when the high corrosion-resistant portland cement is maintained for 28 days, the sulfate corrosion resistance coefficient is 1.3-1.4, and the chloride ion diffusion coefficientIs 0.3-0.5 × 10^-12m²And/s meet the index requirements of national standards of GB/T31289-2014-maritime work Portland cement. In conclusion, the high corrosion resistant Portland cement has better comprehensive performance and can be used for marine buildings with severe marine conditions and long design service life.

In one embodiment of the present invention, the high corrosion resistant portland cement comprises the following components by weight: 50-80% of portland cement clinker, 6-14% of fly ash, 12-30% of cementing material and 4-6% of gypsum.

The invention is further illustrated by the following examples. It is to be understood that the examples are for illustrative purposes only and are not intended to limit the scope and spirit of the present invention.