CN110563335B

CN110563335B - Lead-free transparent fritted glaze and preparation method thereof

Info

Publication number: CN110563335B
Application number: CN201910853138.9A
Authority: CN
Inventors: 黄红军; 郑德胜; 胡岳华; 张群英
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2019-09-10
Filing date: 2019-09-10
Publication date: 2021-12-21
Anticipated expiration: 2039-09-10
Also published as: CN110563335A

Abstract

The invention discloses a lead-free transparent frit glaze and a preparation method thereof. It consists of the following components: 22-32% of potassium feldspar powder with high potassium and low iron, 5-8% of talc powder, 20-28% of quartz sand, Calcium carbonate 13-17%, boric acid 2.5-5%, borax 3.5-6%, zinc oxide 6-8%, strontium carbonate 2.5-4%, barium carbonate 3-5%, magnesium carbonate 1.5-3%, the balance is Lithium Carbonate. The method adopts potassium feldspar powder with high potassium and low iron as raw material, which can reduce the addition of potassium feldspar powder and save raw materials; at the same time, during the firing process of lead-free transparent frit glaze, the lower the iron content is, the lower the iron content is, the more glaze bubbles and There are fewer imperfections such as pinholes, while the frit itself is clearer. In the mixing process of the present invention, the quartz sand is first sprinkled, and then other materials are added in an orderly manner; the purpose is to make water form a water film on the surface of the quartz particles, so as to dissolve part of the solvent-soluble raw materials (such as boric acid, borax), and make the solution Adhesion to the surface of quartz particles, contributing to the accelerated melting of quartz.

Description

Lead-free transparent fritted glaze and preparation method thereof

Technical Field

The invention belongs to the technical field of ceramic materials and production processes, and particularly relates to a lead-free transparent fritted glaze and a preparation method thereof.

Background

Along with the improvement of living standard of people, people pay more and more attention to environmental protection and health, and in the aspects of daily contacted building ceramics, daily ceramics and sanitary ceramics, the safety of use of the daily contacted building ceramics, daily used ceramics and sanitary ceramics becomes the focus of attention besides the fashionable and beautiful appearance of the products. Although the lead glaze ceramic product used in the past has the advantages of good melting property, good transparency, high glossiness, wide glaze firing temperature range, low cost and the like, the lead glaze ceramic product gradually exits the market due to the inevitable lead dissolution phenomenon in the using process and directly harms the body health of producers and consumers, and under the background, the lead-free glaze is produced at present, and through years of research and development of numerous researchers, the lead-free transparent fritted glaze is developed and maturely at present, but compared with similar ceramic products abroad, domestic products mostly have the defects of narrow firing range, poor transparency, low glossiness, high raw material cost and the like. Potassium feldspar is mostly adopted as a raw material of a plurality of lead-free glazes, but the potassium feldspar generally has high iron content and can influence the transparency of the potassium feldspar as a transparent glaze; and the preparation method of a plurality of glaze materials has the characteristic of high cost.

Disclosure of Invention

The invention aims to provide the lead-free transparent fritted glaze with good transparency, high glossiness and low production cost and the preparation method thereof.

The lead-free transparent fritted glaze disclosed by the invention comprises the following raw materials in percentage by mass: 22-32% of high-potassium low-iron potassium feldspar powder, 5-8% of talcum powder, 20-28% of quartz sand, 13-17% of calcium carbonate, 2.5-5% of boric acid, 3.5-6% of borax, 6-8% of zinc oxide, 2.5-4% of strontium carbonate, 3-5% of barium carbonate, 1.5-3% of magnesium carbonate and the balance of lithium carbonate.

Preferably, the mass percent of the high-potassium low-iron potassium feldspar powder is 24-30%, and the mass percent of the quartz sand is 20-26%.

The potassium feldspar powder with high potassium and low iron is K₂Potassium feldspar powder with O content higher than 16% and iron content lower than 0.17%.

The preparation method of the lead-free transparent fritted glaze comprises the following steps:

1) mixing materials: preparing materials according to the proportion of the raw materials, firstly adding quartz sand into a mixer, adding water, uniformly stirring, then adding boric acid, borax, lithium carbonate and strontium carbonate serving as fluxing agents, uniformly stirring, adding the rest other raw materials, and uniformly mixing to obtain a batch mixture;

2) melting: conveying the batch in the step 1) to a smelting furnace, and melting into molten glass;

3) water quenching: pouring the glass liquid obtained in the step 2) into a water tank, performing water quenching and cooling to obtain crisp granular frits, and drying to obtain dry frits;

4) ball milling: adding an additive and water into the dry molten mass in the step 3), and performing wet ball milling to obtain the glaze slurry.

In the step 1), the adding amount of water is 3-5% of the total weight of the raw materials.

In the step 2), in the melting process, firstly adding melted frits which have the same components as the raw materials into a melting furnace, and adding the batch materials in the step 1) after the frits are melted; wherein the mass of the fusion cake is 8-12% of the mass of the batch.

In the step 2), the melting temperature is 1250-1350 ℃, and the melting time is 2-3 h.

In the step 3), the particle size of the granular frit is 1-2 mm, and the drying temperature is 90-110 ℃.

In the step 3), the frit comprises the following chemical components in percentage by mass: SiO 2₂:52.5～56.5％,Al₂O₃:5～7％,Fe₂O₃：0.06～0.08％,CaO:9.5～10.5％,MgO:3～4％,Li₂O:0.1～1％,Na₂O:0.5～1.5％,K₂O:5～6％,ZnO:8～9％,BaO:4～5％,SrO:2～3％,B₂O₃:5～7％。

In the step 4), zirconium oxide is adopted for ball milling in wet grinding; the mass ratio of the zirconia ball grinding balls to the frits to the distilled water is 2:1: 0.4-0.8; the additive is methylcellulose, and the addition amount of the methylcellulose is 0.3 percent of the mass of the clinker. The ball milling time is 1-2 h, and the final ball milling granularity is less than or equal to 10um, and the particles account for more than 90%.

The invention has the beneficial effects that: 1) the invention adopts the potassium feldspar powder which can be high in potassium and low in iron as the raw material, so that the addition of the potassium feldspar powder can be reduced, and the raw material is saved; meanwhile, in the glaze firing process of the lead-free transparent fritted glaze, the lower the iron content is, the less the glaze surface generates flaws such as glaze bubbles and pinholes, and the more clear the fritted glaze. 2) The invention develops Li based on the traditional lead glaze₂The frit glaze prepared according to the formula has the characteristics of wide firing range, good compatibility, high glossiness, good smoothness, good thermal stability and wear resistance, 0 lead dissolution amount and the like, and is widely applicable to the fields of building ceramics, daily ceramics, sanitary ceramics and the like. 3) In the mixing process, the stones are firstly sprinkledQuartz sand, and then adding other materials in order; the purpose is to make water form a water film on the surface of quartz particles so as to dissolve part of solvent soluble raw materials (such as boric acid and borax) and make the solution adhere to the surface of the quartz particles to promote the accelerated melting of the quartz. 4) In the melting process, a small amount of frit with the same components is added in advance, so that firstly, the crucible is slushed and washed, and the corrosion of batch materials to the crucible is reduced; secondly, because the melting point of the remelted frit is lower than that of the batch material melted for the first time, the infusible substances such as quartz and the like in the batch material clamped between the melting bodies are melted at an accelerated speed, the clamping yield is obviously reduced, the quality of the frit is greatly improved, and the energy conservation and emission reduction of a factory are facilitated.

Drawings

FIG. 1 is a report of the detection and analysis of the raw ore components of potash feldspar ore in Jilin.

FIG. 2 is a report of the composition detection analysis of the treated potassium feldspar ore.

Fig. 3 frit pictures prepared in example 1(a) and comparative example 1 (b).

Detailed Description

Pretreatment of potassium feldspar powder: the composition of the raw ore of the potassium feldspar ore of the Jilin₂O 16.52％、Al₂O₃17.81％、SiO₂、Fe₂O₃0.42% of the total weight of the powder is shown in figure 1, and the treated high-potassium low-iron potassium feldspar powder obtained by the treatment method of patent CN201811592181.6 has the composition shown in figure 2 and the composition K₂O 16.39％、Al₂O₃、17.72％，SiO₂65.01％、Fe₂O₃0.17 percent. The pretreated potassium feldspar powder meets the requirements of first-class products in the standard QB/T1636-.

Example 1

The raw material components are as follows: 27.03 percent of high-potassium low-iron-potassium feldspar powder, 6.42 percent of talcum powder, 25.14 percent of quartz sand, 15.05 percent of calcium carbonate, 3.14 percent of boric acid, 5.21 percent of borax, 7 percent of zinc oxide, 3.33 percent of strontium carbonate, 4.63 percent of barium carbonate, 2.02 percent of magnesium carbonate and 0.96 percent of lithium carbonate; sieving the above materials with 60 mesh sieve.

Preparing glaze:

(1) putting quartz sand into a mixer, adding water accounting for 3.5 percent of the total raw material mass, uniformly stirring, adding raw materials of lithium carbonate, strontium carbonate, boric acid and borax fluxing agent, uniformly stirring, adding the rest raw materials, and uniformly stirring for 0.5h to obtain a batch.

(2) Preheating a smelting furnace to 1300 ℃, adding molten clinker with the same components accounting for 8% of the mass of the batch into the furnace, adding the batch after the molten clinker is molten, repeating the steps, and adding a little ready-made molten clinker before each charging; and after 2h of smelting, selecting materials by using iron wires to judge the melting condition, opening a material flowing hole when the selected materials are in a slender, transparent and bubble-free state, allowing glass liquid to flow into a water tank along the hole, and performing water quenching and cooling to obtain the crisp granular lead-free transparent frit.

Wherein the frit comprises the following chemical components: SiO 2₂:53.56％,Al₂O₃:5.46％,Fe₂O₃:0.07％,CaO:9.86％,MgO:3.49％,Li₂O:0.46％,Na₂O:0.99％,K₂O:5.06％,ZnO:8.2％,BaO:4.21％,SrO:2.73％,B₂O₃:5.91％.

(3) Drying the frit in an oven at 100 ℃, placing the frit in a zirconium ball tank, adding CMC (sodium carboxymethyl cellulose) and a proper amount of water, wherein the mass ratio of the CMC to the mass of the frit is 0.3%, and performing ball milling, wherein the mass ratio of zirconia ball milling balls to the frit to the distilled water is 2:1:0.5, after ball milling is performed for 1.5h, the particle size of the glaze slurry is controlled to be less than or equal to 10um, and the particles account for more than 90%, and obtaining the glaze slurry after ball milling.

(4) And (3) applying the glaze slip obtained in the step (3) on the biscuit, slowly heating to 1050 ℃ for glaze firing, preserving the temperature for 30min at the temperature, and cooling to room temperature to obtain the high-quality lead-free transparent frit glaze ceramic product.

Comparative example 1

The clinker was obtained by replacing only the high potassium low iron potassium feldspar powder with untreated potassium feldspar powder according to the process and formulation of example 1. Wherein the frit comprises the following chemical components: SiO 2₂:53.46％,Al₂O₃:5.45％,Fe₂O₃：0.26％,CaO:9.85％,MgO:3.48％,Li₂O:0.46％,Na₂O:0.99％,K₂O:5.05％,ZnO:8.18％,BaO:4.2％,SrO:2.72％,B₂O₃:5.90％(because the iron content in the fusion cake is less, two bits after a decimal point have errors and are normal).

As shown in fig. 2, it can be seen from fig. 2 that the frits prepared in example 1 are colorless and transparent, the frits prepared in comparative example 1 are yellowish, and the transparency of example 1 is significantly better than that of comparative example 1.

Example 2

The raw material components are as follows: 28.58 percent of high-potassium low-iron-potassium feldspar powder, 7.86 percent of talcum powder, 20.63 percent of quartz sand, 15.72 percent of calcium carbonate, 4.91 percent of boric acid, 4.03 percent of borax, 7.86 percent of zinc oxide, 2.95 percent of strontium carbonate, 4.91 percent of barium carbonate, 1.57 percent of magnesium carbonate and 0.98 percent of lithium carbonate after pretreatment; sieving the above materials with 60 mesh sieve.

Preparing glaze:

(1) putting quartz sand into a mixer, adding water accounting for 4% of the total raw material mass, uniformly stirring, adding raw materials of lithium carbonate, strontium carbonate, boric acid and borax fluxing agent, uniformly stirring, adding the rest raw materials, and uniformly stirring for 0.5h to obtain a batch.

(2) Preheating a smelting furnace to 1300 ℃, adding molten clinker with the same components accounting for 10% of the mass of the batch into the furnace, adding the batch after the molten clinker is molten, repeating the steps, and adding a little ready-made molten clinker before each charging; and after 2h of smelting, selecting materials by using iron wires to judge the melting condition, opening a material flowing hole when the selected materials are in a slender, transparent and bubble-free state, allowing glass liquid to flow into a water tank along the hole, and performing water quenching and cooling to obtain the crisp granular lead-free transparent frit.

Wherein the frit comprises the following chemical components: SiO 2₂:53.30％,Al₂O₃:5.32％,Fe₂O₃0.07％,CaO:9.62％,MgO:3.52％,Li₂O:0.44％,Na₂O:0.71％,K₂O:5.0％,ZnO:8.59％,BaO:4.17％,SrO:2.26％,B₂O₃:6.99％。

(3) Drying the frit in an oven at 100 ℃, placing the frit in a zirconium ball tank, adding CMC (sodium carboxymethyl cellulose) and a proper amount of water, wherein the mass ratio of the CMC to the mass of the frit is 0.3%, and performing ball milling, wherein the mass ratio of zirconia ball milling balls to the frit to the distilled water is 2:1:0.8, controlling the particle size of the glaze slurry to be less than or equal to 10um, wherein the particles account for more than 90% after ball milling for 1.5h, and obtaining the glaze slurry after ball milling.

Claims

1. a lead-free transparent frit glaze, is characterized in that, its raw material is made up of following components according to mass percentage: potassium feldspar powder 27.03～28.58% of high potassium and low iron, talcum powder 6.42～7.86%, quartz sand 20.63% ~25.14%, calcium carbonate 15.05~15.72%, boric acid 3.14~4.91%, borax 4.03~5.21%, zinc oxide 7~7.86%, strontium carbonate 2.95~3.33%, barium carbonate 4.63~4.91%, magnesium carbonate 1.57~2.02% , lithium carbonate 0.96~0.98;

The potassium feldspar powder with high potassium and low iron is potassium feldspar powder with K ₂ O content greater than 16% and iron content less than 0.17%;

The preparation method of lead-free transparent frit glaze comprises the following steps:

1) Mixing: Prepare materials according to the proportion of raw materials, then add quartz sand into the mixer first, add water, stir and mix well, then add flux boric acid, borax, lithium carbonate and strontium carbonate, stir and mix well , add the remaining other raw materials, and mix well to get the batching material;

2) Melting: The batch material in step 1) is transported to the furnace and melted into glass liquid;

3) Water quenching: pour the glass liquid in step 2) into a water tank, and after water quenching and cooling, a crisp granular frit is obtained, and after drying, a dry frit is obtained;

4) Ball milling: adding additives and water to the dry frit in step 3), and performing wet ball milling to obtain glaze slurry;

In the step 3), the chemical composition of each component of the frit is composed of the following components according to mass percentage: SiO ₂ : 52.5~56.5%, Al ₂ O ₃ : 5~7%, Fe ₂ O ₃ : 0.06 ~0.08%, CaO: 9.5~10.5%, MgO: 3~4%, Li ₂ O: 0.1~1%, Na ₂ O: 0.5~1.5%, K ₂ O: 5~6%, ZnO: 8~9 %, BaO: 4~5%, SrO: 2~3%, B ₂ O ₃ : 5~7%.

2 . The lead-free transparent frit glaze according to claim 1 , wherein, in the step 1), the amount of water added is 3 to 5% of the total weight of the raw materials. 3 .

3. The lead-free transparent frit glaze according to claim 1, characterized in that, in the step 2), in the melting process, firstly add the already smelted frit with the same composition as the raw material into the furnace, After the frit is melted, the batching material in step 1) is added; wherein the mass of the frit is 8% to 12% of the mass of the batching material.

4 . The lead-free transparent frit glaze according to claim 1 , wherein, in the step 2), the melting temperature is 1250° C.˜1350° C., and the melting time is 2˜3 h. 5 .

5 . The lead-free transparent frit glaze according to claim 1 , wherein in the step 3), the particle size of the granular frit is 1-2 mm, and the drying temperature is 90-110° C. 6 .

6. The lead-free transparent frit glaze according to claim 1, wherein in step 4), zirconia ball milling is adopted for wet grinding; the mass ratio of zirconia grinding balls, frit and distilled water is 2:1 : 0.4~0.8; the additive is methyl cellulose, and its addition amount is 0.3% of the mass of the frit; the ball milling time is 1~2h, and the final ball milling particle size is less than or equal to 10um, accounting for more than 90% of the particles.