阅读说明：本技术 高强度低导热氧化锆复相耐火保温砖的制备方法 (Preparation method of high-strength low-heat-conduction zirconia complex-phase refractory insulating brick ) 是由 张昂 王海啸 韩伟 向帅 于 2020-05-29 设计创作，主要内容包括：本发明涉及一种高强度低导热氧化锆复相耐火保温砖的制备方法,属于耐火保温砖技术领域。本发明所述的高强度低导热氧化锆复相耐火保温砖的制备方法,以氧化锆空心球、钙稳定氧化锆细粉、钙稳定氧化锆微粉和漂珠为原料,添加粘合剂和聚轻球,经过混料、困料、压制成型、干燥和烧成制成。本发明制备的产品不仅具有较高的强度,还具有低导热率,生产成本低,具有显著的经济效益。(The invention relates to a preparation method of a high-strength low-heat-conductivity zirconia complex-phase refractory insulating brick, belonging to the technical field of refractory insulating bricks. The preparation method of the high-strength low-heat-conductivity zirconia complex-phase refractory insulating brick is characterized in that zirconia hollow spheres, calcium-stabilized zirconia fine powder, calcium-stabilized zirconia micro powder and floating beads are used as raw materials, an adhesive and light gathering spheres are added, and the high-strength low-heat-conductivity zirconia complex-phase refractory insulating brick is prepared by mixing, ageing, press forming, drying and firing. The product prepared by the invention not only has higher strength, but also has low thermal conductivity, low production cost and obvious economic benefit.)

1. A preparation method of a high-strength low-heat-conduction zirconia complex-phase refractory insulating brick is characterized by comprising the following steps: the calcium-stabilized zirconia hollow sphere is prepared by taking a zirconia hollow sphere, calcium-stabilized zirconia fine powder, calcium-stabilized zirconia micro powder and floating beads as raw materials, adding an adhesive and a light gathering sphere, mixing, ageing, pressing, forming, drying and sintering.

2. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: the diameter of the zirconia hollow sphere is 0.5-2 mm.

3. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: the particle size of the calcium-stabilized zirconia fine powder is 20-80 μm; the particle size of the calcium-stabilized zirconia micro powder is 5-10 mu m.

4. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: the floating beads are waste floating beads, and the particle size of the floating beads is 0.5-4 mm.

5. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: the adhesive is one or more of cellulose solution or calcium lignosulfonate water solution.

6. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory insulating brick according to claim 5, characterized in that: the mass concentration of the cellulose solution is 5-20%; the mass concentration of the calcium lignosulphonate aqueous solution is 10-30%.

7. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: the poly light ball has particle diameter of 0.5-2mm and density of 0.02-0.04g/cm³。

8. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: the following materials are adopted by mass percent:

9. the preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: the method comprises the following steps:

(1) pouring castor oil into the polymerized light ball for impregnation;

(2) mixing zirconia hollow spheres, calcium-stabilized zirconia fine powder, calcium-stabilized zirconia micro powder, floating beads, poly light spheres soaked with castor oil and an adhesive, ageing, pressing, drying at normal temperature, and firing in a kiln.

10. The preparation method of the high-strength low-thermal-conductivity zirconia complex-phase refractory and heat-insulating brick according to claim 1, characterized in that: ageing for 3-24 hr, pressing under 40-80MPa for 24-72 hr, drying at 1500-1550 deg.c for 2-8 hr, and sintering in kiln.

Technical Field

The invention relates to a preparation method of a high-strength low-heat-conductivity zirconia complex-phase refractory insulating brick, belonging to the technical field of refractory insulating bricks.

Background

Various thermal equipment is an important facility in industrial production and is also an energy consumer, therefore, heat insulation layers and fire-resistant layers of various thermal equipment are all used for heat preservation, fire resistance and heat insulation of refractory bricks, and various refractory bricks are used for ensuring that the thermal equipment is used safely for a long time, and the energy is saved, the consumption is reduced, and the economic benefit is higher.

In order to meet the market demand, numerous refractory insulating brick enterprises develop low-heat-conduction high-strength refractory insulating bricks. At present, the raw materials of the refractory heat-insulating brick made of various materials basically adopt sawdust, poly light ball, kaolin, bauxite chamotte and the like, but the product made of the raw materials belongs to a high-aluminum or silicon-aluminum product, and has the defects of multiple impurity types, high impurity content, poor high-temperature resistance and poor heat-insulating effect, and is difficult to meet the heat-insulating and heat-preserving requirements of high-temperature and light-weight thermal equipment.

The zirconia material not only has the advantages of high melting point, high strength, extremely low thermal conductivity, good chemical stability (erosion resistance) and the like, but also has the advantages of high strength, high temperature resistance, erosion resistance, low thermal conductivity and good heat preservation effect, but also is a reason for difficult popularization due to higher firing temperature and higher raw material cost.

CN 101229979A discloses a heat-insulating universal brick and a manufacturing method thereof, which is prepared by mixing 10-15% of bauxite, 15-25% of synthetic mullite, 25-30% of kaolin, 1-3% of wood chips, 10-18% of poly light balls and 15-20% of floating beads, has excellent high temperature resistance and heat insulation, is used as a heat-insulating fire-resistant heat-insulating material of a special steel cast steel die orifice, but adopts an alumina-silica series material, and only discloses that the density of the prepared product is 0.65-0.72g/cm³The compressive strength, softening onset temperature under load, and thermal conductivity of the product are not disclosed.

Disclosure of Invention

The invention aims to provide a preparation method of a high-strength low-heat-conductivity zirconia complex-phase refractory insulating brick, and the prepared product has high strength, low heat conductivity, low production cost and obvious economic benefit.

The preparation method of the high-strength low-heat-conductivity zirconia complex-phase refractory insulating brick is characterized in that zirconia hollow spheres, calcium-stabilized zirconia fine powder, calcium-stabilized zirconia micro powder and floating beads are used as raw materials, an adhesive and light gathering spheres are added, and the high-strength low-heat-conductivity zirconia complex-phase refractory insulating brick is prepared by mixing, ageing, press forming, drying and firing.

Preferably, the diameter of the zirconia hollow sphere is 0.5-2 mm.

Preferably, the particle size of the calcium stabilized zirconia fine powder is 20 to 80 μm.

Preferably, the particle size of the calcium-stabilized zirconia fine powder is 5 to 10 μm.

Preferably, the floating beads are waste floating beads, and the particle size of the waste floating beads is 0.5-4 mm.

Preferably, the binder is one or more of a cellulose solution or an aqueous solution of calcium lignosulfonate.

Further preferably, the mass concentration of the cellulose solution is 5-20%; the mass concentration of the calcium lignosulphonate aqueous solution is 10-30%.

Preferably, the poly-light ball has a particle size of 0.5-2mm and a density of 0.02-0.04g/cm³。

The preparation method of the high-strength low-heat-conductivity zirconia complex-phase fireproof insulating brick adopts the following materials in percentage by mass:

the preparation method of the high-strength low-heat-conductivity zirconia complex-phase fireproof insulating brick preferably comprises the following steps:

(1) pouring a proper amount of castor oil into the polymerized light balls for impregnation, wherein the use amount of the castor oil is based on the condition that the polymerized light balls are immersed in the castor oil;

(2) mixing zirconia hollow spheres, calcium-stabilized zirconia fine powder, calcium-stabilized zirconia micro powder, floating beads, poly light spheres dipped with castor oil and an adhesive, ageing the mixture for 3 to 24 hours, pressing the mixture to form the mixture under 40 to 80MPa, drying the mixture for 24 to 72 hours at normal temperature, putting the mixture into a kiln for sintering, keeping the sintering temperature at 1500 ℃ and 1550 ℃ and preserving the heat for 2 to 8 hours.

According to the invention, zirconia is used as a main crystal phase, mullite and zirconite are used as a secondary crystal phase, the high-temperature characteristics of the zirconia hollow sphere, the calcium-stabilized zirconia fine powder, the calcium-stabilized zirconia micro powder and the floating bead are fully exerted, the excellent performance of ultralow thermal conductivity is realized by utilizing the porous structure of the product, and meanwhile, the added pore-forming agent made of other materials obviously reduces the comprehensive cost of the product.

In the preparation process, the floating characteristic of the poly light balls is fully considered, and the uniform mixing degree of the poly light balls is improved after the poly light balls are soaked by the castor oil, so that the poly light balls are fully dispersed in other raw materials; in addition, the castor oil has high hydroxyl content and high viscosity, so that the raw materials are favorably bonded together; the castor oil only contains C, H, O elements, and generates harmless gas under the action of high temperature in the sintering process.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the invention, the advantages of the zirconia material are fully utilized, the zirconia hollow spheres with different particle sizes, the calcium-stabilized zirconia fine powder and the calcium-stabilized zirconia fine powder are organically mixed together, and the prepared product takes zirconia as a main crystal phase and mullite and zirconite as a secondary crystal phase;

(2) the light gathering balls are introduced, so that the porosity of the product is increased, and the production cost is obviously reduced;

(3) the floating beads introduced by the invention can utilize waste floating beads, realize waste recycling, save energy and protect environment;

(4) the volume density of the product prepared by the invention is 0.8-1.5g/cm³The room temperature compressive strength is 5-15MPa, the 0.1MPa refractoriness under load is 1580-;

(5) the method is simple and easy to implement, is beneficial to industrial production, and has remarkable economic benefit.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the practice of the invention.