阅读说明：本技术 一种白色硅酸盐水泥熟料及其制备工艺 (White portland cement clinker and preparation process thereof ) 是由 杨德勇 陈武双 于 2019-11-20 设计创作，主要内容包括：本发明涉及一种白色硅酸盐水泥熟料以及制备工艺,包括以下重量百分比计原料制成：硅石16-18%；铝矾土0.5-0.7%；矿化剂0.8-1%；石灰石余量。通过采用本发明中的原料配比,提高白色硅酸盐水泥熟料白度和强度的同时,降低了白水泥熟料的KH值,使得熟料从原来的KH：0.98±0.02和n：5.2±0.1,调整为KH：0.95±0.02、n：6.1±0.1,从而使得窑的煅烧变得好控制,便于熟料的制得,以及提高了熟料的质量,合格率大大提高,降低了生产成本。(The invention relates to a white portland cement clinker and a preparation process thereof, wherein the white portland cement clinker is prepared from the following raw materials in percentage by weight: 16-18% of silica; 0.5 to 0.7 percent of bauxite; 0.8 to 1 percent of mineralizer; and (4) the balance of limestone. By adopting the raw material proportion in the invention, while the whiteness and the strength of the white portland cement clinker are improved, the KH value of the white cement clinker is reduced, so that the white portland cement clinker is prepared from the original KH: 0.98 ± 0.02 and n: 5.2 +/-0.1, adjusting to KH: 0.95 ± 0.02, n: 6.1 +/-0.1, thereby leading the calcination of the kiln to be well controlled, being convenient for preparing clinker, improving the quality of the clinker, greatly improving the qualification rate and reducing the production cost.)

1. A white portland cement clinker is characterized in that: the material is prepared from the following raw materials in percentage by weight:

2. a white portland cement clinker as recited in claim 1, wherein: the white portland cement clinker also comprises the following raw materials in percentage by weight: 0.2-0.4% of bleaching agent.

3. A white portland cement clinker as recited in claim 2, wherein: the bleaching agent comprises the following raw materials in percentage by weight:

30-40% of barium sulfate;

30-40% of coke;

20-40% of ammonium chloride.

4. A white portland cement clinker as recited in claim 1, wherein: the mineralizer adopts CaF₂Natural fluorite with content over 50%.

5. A preparation process of white portland cement clinker is characterized by comprising the following steps: the method comprises the following process steps:

s1: crushing raw materials: crushing silica, bauxite, a mineralizer and limestone into blocks;

s2: raw material proportioning: taking the following raw materials in percentage by weight:

s3: grinding raw materials: mixing the raw materials in the step S2, and then grinding to obtain a grinding material;

s4: raw material homogenization: homogenizing the ground material to obtain a homogenized material;

s5: calcining clinker: introducing the homogenized material into a rotary kiln for calcination treatment, and obtaining finished clinker after the calcination treatment is finished;

s6: and (3) clinker storage: and (5) warehousing and storing the finished product clinker obtained in the step S5.

6. A process for the preparation of a white Portland cement clinker according to claim 5, characterized in that: the clinker after the calcination in the step S5 is further processed by: and grinding the calcined clinker into powder, adding a whitening agent, and stirring for 20-30min under a vacuum condition to obtain a finished product clinker.

7. A white Portland cement clinker according to claim 6, characterized in that: the weight ratio of the whitening agent to the calcined clinker is 1: (2-3).

8. A white Portland cement clinker according to claim 7, characterized in that: the whitening agent is prepared from the following raw materials in percentage by weight: 26-30% of kiln dust, 20-24% of pyrophyllite, 16-20% of cellulose nanocrystal, 1-5% of silane coupling agent and the balance of deionized water.

9. The process for preparing a white portland cement clinker according to claim 8, wherein: the particle size of the whitening agent is 0.1-0.3 micron.

10. A process for the preparation of a white Portland cement clinker according to claim 5, characterized in that: the residue on a 45-micron sieve of the finished clinker is less than or equal to 1 percent.

Technical Field

The invention relates to the technical field of cement manufacture, in particular to white portland cement clinker and a preparation process thereof.

Background

White cement, also known as white portland cement, is widely used in the construction industry. The white cement is prepared by using clay and limestone with low iron content as main raw materials through the steps of proportioning, grinding, molding, calcining and grinding.

The white cement has the gelatinization characteristic and excellent physical and mechanical properties of common portland cement, and has bright white luster and beautiful elegance. With the rapid development of national economy, the requirements of people on living environment are higher and higher, and the quality requirements on white cement are further improved.

However, when white cement clinker is prepared, the KH value (lime saturation coefficient) of the white cement clinker is generally increased to about 0.98 so as to improve the whiteness of the white cement clinker. Although the larger the KH value of the white cement clinker, C₃The higher the S content is, the cement has the characteristics of high hardness and high strength and has higher whiteness; however, the calcination temperature is required to be higher, and when calcination is insufficient, clinker contains more free calcium oxide, which affects the stability of the clinker.

Disclosure of Invention

The invention aims to provide a white portland cement clinker and a preparation process thereof, which can improve the whiteness and the strength of the white portland cement clinker and reduce the KH value of the white cement clinker, thereby facilitating the preparation of the clinker and reducing the production cost.

The above object of the present invention is achieved by the following technical solutions:

the white portland cement clinker is prepared from the following raw materials in percentage by weight:

by adopting the technical scheme, the whiteness and the strength of the white portland cement clinker are improved, and meanwhile, the KH value of the white cement clinker is reduced, so that the clinker is changed from the original KH: 0.98 ± 0.02 and n: 5.2 +/-0.1, adjusting to KH: 0.95 ± 0.02, n: 6.1 +/-0.1, thereby leading the calcination of the kiln to be well controlled, being convenient for preparing clinker, improving the quality of the clinker, greatly improving the qualification rate and reducing the production cost.

The invention is further configured to: the white portland cement clinker also comprises the following raw materials in percentage by weight: 0.6-1% of bleaching agent.

By adopting the technical scheme, the bleaching agent is added for bleaching the clinker, so that the whiteness of the white cement clinker is improved, and the strength of the white cement clinker is improved.

The invention is further configured to: the bleaching agent comprises the following raw materials in percentage by weight:

30-40% of barium sulfate;

30-40% of coke;

20-40% of ammonium chloride.

By passingBy adopting the technical scheme, the barium ions in the barium sulfate can be replaced by calcium ions during calcination, so that the whiteness and the strength of the white cement clinker are improved, the effects of quick hardening and block coagulation of the white cement clinker are achieved, and the early strength of the white cement is improved. And barium sulfate can be compounded with fluorite for use to generate synergistic effect, so that C in clinker is improved₃The forming speed and the forming amount of S, thereby improving the strength and the whiteness of the white cement clinker.

During calcination, coke reacts with oxygen and carbon dioxide to generate carbon monoxide with reducing property, so as to reduce coloring metal oxide (ferric oxide) and improve whiteness of white cement clinker.

The ammonium chloride can react with ferric oxide in the clinker to form ferric chloride which is removed, thereby improving the whiteness of the white cement clinker. Meanwhile, the pH value of the raw material is adjusted to make the raw material be slightly alkaline, so that the lowest eutectic temperature of a material system is reduced, the liquid phase quantity is increased, the liquid phase viscosity is reduced, and the burnability of the raw material is improved.

The invention is further configured to: the mineralizer adopts CaF₂Natural fluorite with content over 50%.

A preparation process of white portland cement clinker comprises the following process steps:

s1: crushing raw materials: crushing silica, bauxite, a mineralizer and limestone into blocks;

s2: raw material proportioning: taking the following raw materials in percentage by weight:

s3: grinding raw materials: mixing the raw materials in the step S2, and then grinding to obtain a grinding material;

s4: raw material homogenization: homogenizing the ground material to obtain a homogenized material;

s5: calcining clinker: introducing the homogenized material into a rotary kiln for calcination treatment, and obtaining finished clinker after the calcination treatment is finished;

s6: and (3) clinker storage: and (5) warehousing and storing the finished product clinker obtained in the step S5.

The invention is further configured to: the clinker after the calcination in the step S5 is further processed by: and grinding the calcined clinker into powder, adding a whitening agent, and stirring for 20-30min under a vacuum condition to obtain a finished product clinker.

By adopting the technical scheme, the clinker is stirred for 20-30min under the vacuum condition, and the adhesion amount and the adhesion effect of the whitening agent on the clinker are improved, so that the light reflecting capacity of the surface of the clinker and the mechanical strength of the clinker are improved, and the whiteness of the clinker is increased.

The invention is further configured to: the weight ratio of the whitening agent to the calcined clinker is 1: (2-3).

By adopting the technical scheme, the whitening agent is added to block the pores on the surface of the clinker and improve the smoothness of the surface of the clinker, thereby improving the light reflecting capacity of the surface of the clinker and the whiteness of the clinker.

The invention is further configured to: the whitening agent is prepared from the following raw materials in percentage by weight: 26-30% of kiln dust, 20-24% of pyrophyllite, 16-20% of cellulose nanocrystal, 1-5% of silane coupling agent and the balance of deionized water.

By adopting the technical scheme, after the clinker is calcined, the porosity of the clinker is increased, so that the surface of the clinker is rough, and the reflection effect of the clinker on light is influenced. The kiln dust, the pyrophyllite and the cellulose nanocrystals are added to block pores on the surface of the clinker, so that the smoothness of the surface of the clinker is improved, and the light reflecting capacity of the surface of the clinker and the whiteness of the clinker are improved. And the kiln dust and the pyrophyllite both have good mechanical strength and whiteness, and the whiteness of the clinker is not reduced while the strength of the clinker is improved.

After the cellulose nanocrystals are attached to the surface of white cement clinker, the light-reflecting capacity of the clinker surface is enhanced, so that the whiteness of the clinker is increased. The silane coupling agent is used for modifying the kiln dust, the pyrophyllite and the cellulose nanocrystals, and improving the bonding strength of the kiln dust, the pyrophyllite and the cellulose nanocrystals on the surface of clinker and the dispersion uniformity on the surface of the clinker, so that the surface of the clinker is smoother, and the whiteness of the clinker is improved.

The invention is further configured to: the particle size of the whitening agent is 0.1-0.3 micron.

By adopting the technical scheme, the particle size of the whitening agent is 0.1-0.3 micron, so that the whitening agent is convenient to attach to the surface of the clinker, and is used for blocking pores on the surface of the clinker and improving the smoothness degree of the surface of the clinker, thereby improving the light reflecting capacity of the surface of the clinker and the whiteness of the clinker. The particle size of the whitening agent is prevented from being too small, so that the dispersibility of the whitening agent is influenced, or the particle size of the whitening agent is prevented from being too large, so that the adhesion of the whitening agent on the surface of clinker is influenced.

The invention is further configured to: the residue on a 45-micron sieve of the finished clinker is less than or equal to 1 percent.

In conclusion, the beneficial technical effects of the invention are as follows:

1. by adopting the raw material proportion in the invention, while the whiteness and the strength of the white portland cement clinker are improved, the KH value of the white cement clinker is reduced, so that the white portland cement clinker is prepared from the original KH: 0.98 ± 0.02 and n: 5.2 +/-0.1, adjusting to KH: 0.95 ± 0.02, n: 6.1 +/-0.1, so that the calcination of the kiln becomes well controlled, the clinker is convenient to prepare, the quality of the clinker is improved, the qualification rate is greatly improved, and the production cost is reduced;

2. by adding the bleaching agent to bleach the clinker, the whiteness of the white cement clinker is improved, and the strength of the white cement clinker is improved;

3. the whitening agent is added to block pores on the surface of the clinker, so that the smoothness of the surface of the clinker is improved, and the light reflecting capacity of the surface of the clinker and the whiteness of the clinker are improved.

Detailed Description