阅读说明：本技术 一种用于卫生陶瓷的低锆洁白釉及其制备工艺 (Low-zirconium white glaze for sanitary ceramics and preparation process thereof ) 是由 伍军玲 潘欢欢 钟保民 徐瑜 于 2019-11-04 设计创作，主要内容包括：一种用于卫生陶瓷的低锆洁白釉及其制备工艺,其低锆洁白釉按质量分数,包括以下原料：6.5-7.5％的硅酸锆、24-27％的石英、5-7％的高岭土、2.5-3.5％的氧化铝、12-18％的钾长石、9-15％的钠长石、6-8.5％的方解石、9-13％的硅灰石、2-5％的白云石、2-3.5％的烧滑石、2-3.5％的氧化锌和1.5-4％的熔块；其制备工艺通过步骤(1)-(3)的操作,制备出低锆洁白釉。本发明能在较低的硅酸锆含量条件下,仍能保持高光泽度、陶瓷白度、高温流动性和低放射性,使本品既具有有高光泽度、高陶瓷白度、较好的高温流动性和放射性低的效果。(A low-zirconium white glaze for sanitary ceramics and a preparation process thereof are disclosed, wherein the low-zirconium white glaze comprises the following raw materials in percentage by mass: 6.5-7.5% of zirconium silicate, 24-27% of quartz, 5-7% of kaolin, 2.5-3.5% of alumina, 12-18% of potassium feldspar, 9-15% of sodium feldspar, 6-8.5% of calcite, 9-13% of wollastonite, 2-5% of dolomite, 2-3.5% of calcined talc, 2-3.5% of zinc oxide and 1.5-4% of frit; the preparation process comprises the steps (1) to (3) to prepare the low-zirconium white glaze. The invention can still maintain high glossiness, ceramic whiteness, high temperature fluidity and low radioactivity under the condition of lower zirconium silicate content, so that the product has the effects of high glossiness, high ceramic whiteness, better high temperature fluidity and low radioactivity.)

1. The low-zirconium white glaze for sanitary ceramics is characterized by comprising the following raw materials in parts by mass: 6.5 to 7.5 percent of zirconium silicate, 24 to 27 percent of quartz, 5 to 7 percent of kaolin, 2.5 to 3.5 percent of alumina, 12 to 18 percent of potassium feldspar, 9 to 15 percent of sodium feldspar, 6 to 8.5 percent of calcite, 9 to 13 percent of wollastonite, 2 to 5 percent of dolomite, 2 to 3.5 percent of calcined talc, 2 to 3.5 percent of zinc oxide and 1.5 to 4 percent of frit.

2. The low-zirconium white glaze for sanitary ceramics according to claim 1, wherein Na in the low-zirconium white glaze⁺And K⁺The content ratio of (0.9-1.1) to (1).

3. The low-zirconium white glaze for sanitary ceramics according to claim 1, wherein Ca in the low-zirconium white glaze²⁺The content of (A) is less than 11%.

4. The sanitary ceramic low-zirconium white glaze according to claim 1, wherein wollastonite is sieved by a 400-mesh screen, and the balance is less than 3%;

the quartz is filtered by a 325-mesh screen, and the balance is less than 1%;

the calcined talc is sieved by a 325-mesh screen, and the balance is less than 5%;

the zirconium silicate has a content of > 98.5% with a particle size of less than 10 μm.

5. A preparation process of low-zirconium white glaze is characterized by comprising the following steps:

(1) mixing the raw materials including zirconium silicate, wollastonite, dolomite, frit and burning talc, ball-milling until the content of the clinker with the granularity less than 10 mu m accounts for 70-74 percent, and preparing the whitening agent;

(2) mixing the raw materials including quartz, kaolin, alumina, potash feldspar, albite, calcite and zinc oxide, adding the mixture into a ball, and adding the whitening agent in the step (1) when the ball milling granularity is lower than 10 mu m and the content of the whitening agent accounts for 45-65%; continuously carrying out ball milling and uniformly mixing to obtain coarse white glaze;

(3) and (4) removing iron from the coarse white glaze and sieving to obtain the low-zirconium white glaze.

6. The process for preparing a low-zirconium white glaze according to claim 3, wherein in the step (2), after the brightener is added, the glaze slurry is ball-milled until the content of the glaze slurry with the particle size of less than 10 μ is 56-60%, and the glaze slurry is sieved by a 325-mesh screen, and the balance is less than or equal to 0.1%.

7. The process for preparing a low-zirconium white glaze according to claim 6, wherein the coarse white glaze passes through a screen of 160-200 meshes.

8. The process for preparing a low-zirconium white glaze according to claim 6, wherein the step (3) is performed at least 2 times.

9. The process for preparing the low-zirconium white glaze according to claim 5, wherein the low-zirconium white glaze is prepared according to the proportion of the low-zirconium white glaze according to any one of claims 1 to 4.

Technical Field

The invention relates to the technical field of ceramic glaze, in particular to low-zirconium white glaze for sanitary ceramics and a preparation process thereof.

Background

The existing ceramic glaze can use a large amount of zirconium silicate to achieve high brightness and high whiteness, and the internal composition and matching of the whole ceramic glaze are not considered after the zirconium silicate is used, so that although the finished product has high whiteness, the finished product has unsatisfactory processability, product performance and environmental protection; particularly, in the aspect of radioactivity, impurities of zirconium silicate contain radioactive substances, so that the use of the zirconium silicate needs to be reduced as much as possible in the actual preparation process; it is therefore the current direction of research how to reduce the use of zirconium silicate and without affecting the performance of high whiteness.

Disclosure of Invention

The invention aims to provide a low-zirconium white glaze for sanitary ceramics, which is added with burning talc and reduces the content of zirconium silicate.

The invention also provides a preparation process of the low-zirconium white glaze for sanitary ceramics, which can prepare the low-zirconium white glaze.

In order to achieve the purpose, the invention adopts the following technical scheme:

the low-zirconium white glaze for sanitary ceramics comprises the following raw materials in percentage by mass: 6.5 to 7.5 percent of zirconium silicate, 24 to 27 percent of quartz, 5 to 7 percent of kaolin, 2.5 to 3.5 percent of alumina, 12 to 18 percent of potassium feldspar, 9 to 15 percent of sodium feldspar, 6 to 8.5 percent of calcite, 9 to 13 percent of wollastonite, 2 to 5 percent of dolomite, 2 to 3.5 percent of calcined talc, 2 to 3.5 percent of zinc oxide and 1.5 to 4 percent of frit.

Further, the low-zirconium white glaze contains Na⁺And K⁺The content ratio of (0.9-1.1) to (1).

Further, Ca in the low-zirconium white glaze²⁺The content of (A) is less than 11%.

Further, the wollastonite is sieved by a 400-mesh sieve, and the balance is less than 3%;

the quartz is filtered by a 325-mesh screen, and the balance is less than 1%;

the calcined talc is sieved by a 325-mesh screen, and the balance is less than 5%;

the zirconium silicate has a content of > 98.5% with a particle size of less than 10 μm.

A preparation process of low-zirconium white glaze comprises the following steps:

(1) mixing the raw materials including zirconium silicate, wollastonite, dolomite, frit and burning talc, ball-milling until the content of the clinker with the granularity less than 10 mu m accounts for 70-74 percent, and preparing the whitening agent;

(2) mixing the raw materials including quartz, kaolin, alumina, potash feldspar, albite, calcite and zinc oxide, adding the mixture into a ball, and adding the whitening agent in the step (1) when the ball milling granularity is lower than 10 mu m and the content of the whitening agent accounts for 45-65%; continuously carrying out ball milling and uniformly mixing to obtain coarse white glaze;

(3) and (4) removing iron from the coarse white glaze and sieving to obtain the low-zirconium white glaze.

Further, in the step (2), after the whitening agent is added, the glaze slurry is ball-milled until the content of the glaze slurry with the granularity lower than 10 mu is 56-60%, and the glaze slurry passes through a 325-mesh screen, and the balance is less than or equal to 0.1%.

Further, the coarse white glaze passes through a screen with 160-200 meshes.

More specifically, the step (3) is performed at least 2 times.

The invention has the beneficial effects that:

the low-zirconium white glaze is prepared by adding albite and potash feldspar for matching, adding calcined talc for matching wollastonite and frit, and controlling Ca²⁺The content of the zirconium silicate is not more than 11 percent, and the obtained product can still keep high glossiness, ceramic whiteness, high temperature fluidity and low radioactivity under the condition of lower zirconium silicate content, so that the product has the effects of high glossiness, high ceramic whiteness, better high temperature fluidity and low radioactivity.

Drawings

FIG. 1 is an XRD crystal phase analysis chart of the glaze powder prepared in example D2.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

The low-zirconium white glaze for sanitary ceramics comprises the following raw materials in percentage by mass: 6.5 to 7.5 percent of zirconium silicate, 24 to 27 percent of quartz, 5 to 7 percent of kaolin, 2.5 to 3.5 percent of alumina, 12 to 18 percent of potassium feldspar, 9 to 15 percent of sodium feldspar, 6 to 8.5 percent of calcite, 9 to 13 percent of wollastonite, 2 to 5 percent of dolomite, 2 to 3.5 percent of calcined talc, 2 to 3.5 percent of zinc oxide and 1.5 to 4 percent of frit.

The low-zirconium white glaze is prepared by adding albite and potash feldspar for matching, adding calcined talc for matching wollastonite and frit, and controlling Ca²⁺The content of the zirconium silicate is not more than 11 percent, and the obtained product can still keep high glossiness, ceramic whiteness, high temperature fluidity and low radioactivity under the condition of lower zirconium silicate content, so that the product has the effects of high glossiness, high ceramic whiteness, better high temperature fluidity and low radioactivity.

Further, the low-zirconium white glaze contains Na⁺And K⁺The content ratio of (0.9-1.1) to (1).

Na⁺The main source of (A) is Na of albite₂O；K⁺The main source of (A) is K of potassium feldspar₂O; both of them are used as alkaline flux to dissolve zircon and promote the formation of fine zirconium silicate crystal, when Na is present⁺And K⁺When the content ratio is close to 1, Zr suppression is most advantageous⁴⁺The crystal type transformation of the zirconium silicate promotes the formation of fine crystals of the zirconium silicate, thereby achieving the whitening effect.

Further, Ca in the low-zirconium white glaze²⁺The content of (A) is less than 11%.

Ca²⁺Can inhibit Zr⁴⁺The crystal form of (b) is changed, thereby contributing to the opacifying effect, but when Ca is used²⁺When the content of (B) exceeds 11%, CaO, MgO, 2SiO in the glaze is promoted₂CaO & Al decomposed to form transparent₂O₃·2SiO₂And reduces the opacifying effect. Meanwhile, it is to be noted that Ca in this case²⁺Refers to Ca in the low-zirconium white glaze²⁺The primary source is CaO in dolomite, wollastonite, frit or calcite.

Further, the wollastonite is sieved by a 400-mesh sieve, and the balance is less than 3%;

the quartz is filtered by a 325-mesh screen, and the balance is less than 1%;

the calcined talc is sieved by a 325-mesh screen, and the balance is less than 5%;

the zirconium silicate has a content of > 98.5% with a particle size of less than 10 μm.

The early-stage mixing and ball milling can increase the combination degree of all the substances, inhibit the crystal transformation of zirconium silicate to the maximum extent, and control the proper particle size to accelerate the formation of CaO, MgO, 2SiO₂The finer the granularity is, the lower the reaction temperature can be, and the crystal forming time can be prolonged under the condition of ensuring that the performance of the glaze slip is not influenced. Therefore, the ball milling time can be reduced by controlling the conditions of the raw materials, a more fine and stable glaze surface can be obtained, and the formation of crystals in the glaze can be promoted.

A preparation process of low-zirconium white glaze comprises the following steps:

(1) mixing the raw materials including zirconium silicate, wollastonite, dolomite, frit and burning talc, ball-milling until the content of the clinker with the granularity less than 10 mu m accounts for 70-74 percent, and preparing the whitening agent;

(2) mixing the raw materials including quartz, kaolin, alumina, potash feldspar, albite, calcite and zinc oxide, adding the mixture into a ball, and adding the whitening agent in the step (1) when the ball milling granularity is lower than 10 mu m and the content of the whitening agent accounts for 45-65%; continuously carrying out ball milling and uniformly mixing to obtain coarse white glaze;

(3) and (4) removing iron from the coarse white glaze and sieving to obtain the low-zirconium white glaze.

Further, in the step (2), after the whitening agent is added, the glaze slurry is ball-milled until the content of the glaze slurry with the granularity lower than 10 mu is 56-60%, and the glaze slurry passes through a 325-mesh screen, and the balance is less than or equal to 0.1%.

Further, the coarse white glaze passes through a screen with 160-200 meshes.

More specifically, the step (3) is performed at least 2 times. The iron removal needs to be carried out by mixing an iron remover and a magnetic bar, and needs to be carried out twice, so that iron impurities are prevented from being generated and the whiteness of the glaze surface is reduced.

Further, in the preparation process, the low-zirconium white glaze comprises the following raw materials in percentage by mass: 6.5-7.5% of zirconium silicate, 24-27% of quartz, 5-7% of kaolin, 2.5-3.5% of alumina, 12-18% of potassium feldspar, 9-15% of sodium feldspar, 6-8.5% of calcite, 9-13% of wollastonite, 2-5% of dolomite, 2-3.5% of calcined talc, 2-3.5% of zinc oxide and 1.5-4% of frit;

and is defined by any one or more of the following conditions:

A. na in low-zirconium white glaze⁺And K⁺The content ratio of (0.9-1.1) to (1);

B. ca in the low-zirconium white glaze²⁺The content of (A) is less than 11%;

C. the wollastonite passes through a 400-mesh screen, and the balance is less than 3%; the quartz is filtered by a 325-mesh screen, and the balance is less than 1%; the calcined talc is sieved by a 325-mesh screen, and the balance is less than 5%; the zirconium silicate has a content of > 98.5% with a particle size of less than 10 μm.

And (3) performance testing:

gloss:

measured directly with a Graeme MN60-D gloss meter.

And (3) ceramic whiteness:

the higher the ceramic whiteness value is, the whiter the glaze is when the ceramic is detected by the Shanghai plain Xuan WSB-2 model.

High temperature fluidity:

the GB/T23460.1-2009 ceramic glaze performance test method is used, which means that the glaze flows viscously in the melting process, and in the range of the melting length of 50-70mm, the better the fluidity is, the fewer the glaze surface pinholes are, and the better the glaze surface flatness is.

Radioactivity:

the synthesized glaze is applied to a closestool, the working environment of the application is adopted, and a low-background multi-channel energy spectrometer is used for detecting the same position.