Ultralow cement corundum castable formula and construction process

Abstract

The invention discloses an ultralow cement corundum castable formula which comprises the following components in percentage by weight: 32.5% of AL2O3 aggregate with the granularity of 1-3mm and the content of AL2O3 of more than or equal to 70, 32.5% of AL2O3 aggregate with the granularity of 3-8 and the content of AL2O3 of more than or equal to 70, 21.75% of 200-mesh aluminum oxide fine powder and alpha-aluminum oxide powder gt, 4% of 99% ultrafine activated alumina powder and 2% of kyanite powder with the purity of gt; 93% and a flow value gt; 10% of silica powder, 0.2% of sodium tripolyphosphate, 0.05% of expanded fiber and 2% of 80 # pure calcium aluminate cement. The invention also discloses a construction method of the ultralow cement corundum castable. Under the working condition that the highest use temperature reaches 1350 DEG C, the furnace lining is high in compressive strength, high in breaking strength, long in high-temperature service life, good in thermal stability and short in curing and demolding time.

Description

Technical Field

[0001] The invention relates to the technical field of industrial furnace refractory materials, and in particular to a formula and construction process of an ultra-low cement corundum castable. Background Art

[0002] In the prior art, the refractory layer of the furnace lining in a 1300℃ gas-fired industrial furnace is mostly made of low-cement castables. However, if the maximum operating temperature reaches 1350℃, the introduction of CaO in the cement will react with AL2O3 and alumina in the material at high temperature to form low-melting products such as calcite, causing the softening temperature of the material to decrease and the thermal shock stability to deteriorate, thereby shortening the high-temperature service life of the furnace lining and causing poor thermal stability. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention proposes an ultra-low cement corundum castable formula and construction process which can solve the problems of short high temperature service life and poor thermal stability of furnace lining under working conditions where the maximum operating temperature reaches 1350°C.

[0004] The present invention achieves the technical objectives through the following technical solutions.

[0005] The improvement of the formula of ultra-low cement corundum castable is as follows: by weight: 32.5% of AL2O3 aggregate with a particle size of 1-3mm and an AL2O3 content of ≥70, 32.5% of AL2O3 aggregate with a particle size of 3-8 and an AL2O3 content of ≥70, 21.75% of 200-mesh aluminum oxide fine powder, 4% of ultrafine activated alumina powder with an α-alumina powder content of >99%, 2% of kyanite powder, 5% of silica powder with a purity of >93% and a flow value of >10, 0.2% of sodium tripolyphosphate, 0.05% of expanded fiber, and 2% of No. 80 pure calcium aluminate cement.

[0006] The above-mentioned ultra-low cement corundum castable construction method comprises the following steps:

[0007] (1) Prepare ingredients according to the above formula;

[0008] (2) Prepare purified water according to drinking water standards;

[0009] (3) First, pour Al2O3 aggregate, 200 mesh aluminum oxide powder, ultrafine activated alumina powder with an α-alumina powder content of >99%, kyanite powder, silica powder with a purity of >93% and a flow value of >10, sodium tripolyphosphate, expanded fiber, and No. 80 pure calcium aluminate cement into a mixer and dry mix for 2 to 3 minutes, then add 1 to 5% by weight of the above ingredients of purified water, wet mix for 4 to 6 minutes, and the mixer speed is greater than 25 rpm;

[0010] (4) After the ingredients are mixed, they should be put into construction immediately and used within 30 minutes;

[0011] (5) After the construction is completed, the surface of the construction body is initially solidified and naturally dried for 24 hours;

[0012] (6) Repair the surface of the construction body immediately after removing the formwork;

[0013] (7) Bake according to the oven curve.

[0014] Compared with the prior art, the present invention has the following positive effects: by adopting the formula of the present invention and carrying out construction according to the present invention, the compressive strength and flexural strength of the furnace lining under the condition where the maximum operating temperature reaches 1350°C are significantly improved, the high-temperature service life and thermal stability of the furnace lining are significantly improved, and the maintenance and demoulding time are significantly shortened. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] The construction of ultra-low cement corundum castable includes the following steps:

[0017] (1) The ingredients are prepared according to the following formula (by weight): 32.5% of Al2O3 aggregate with a particle size of 1-3 mm and an Al2O3 content of ≥70%, 32.5% of Al2O3 aggregate with a particle size of 3-8 and an Al2O3 content of ≥70%, 21.75% of 200-mesh aluminum oxide fine powder, 4% of ultrafine activated alumina powder with an α-alumina powder content of >99%, 2% of kyanite powder, 5% of silica powder with a purity of >93% and a flow value of >10, 0.2% of sodium tripolyphosphate, 0.05% of expanded fiber, and 2% of No. 80 pure calcium aluminate cement;

[0018] (2) preparing 5% by weight of the ingredients in step (1) of pure water according to drinking water standards;

[0019] (3) First, pour AL2O3 aggregate, 200 mesh aluminum oxide fine powder, ultrafine activated alumina powder with an α-alumina powder content of >99%, lanzenite powder, silica powder with a purity of >93% and a flow value of >10, sodium tripolyphosphate, expanded fiber, and 80# pure calcium aluminate cement into a mixer and dry mix for 2-3 minutes, then add 1-5% pure water according to climatic conditions, environment, and humidity, and wet mix for 4-6 minutes, with the mixer rotating at a speed of more than 25 rpm;

[0020] (4) After the ingredients are mixed, they should be put into construction immediately and used within 30 minutes;

[0021] (5) After the construction is completed, the surface of the construction body is initially solidified and naturally dried for 24 hours;

[0022] (6) Repair the surface of the construction body immediately after removing the formwork;

[0023] (7) Bake according to the oven curve.

[0024] After construction, the compressive strength of the furnace lining is increased by 18-22% under the condition of the maximum operating temperature reaching 1350℃, the flexural strength is increased by 16-21%, the thermal stability is increased by 14-18%, the service life is >6 years, an increase of more than 20%, and the maintenance and demoulding time is shortened to 1 day (1 day shorter than low-cement castable).

[0025] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0026] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A formula of ultra-low cement corundum castable, characterized by: The weight ratio is as follows: 32.5% AL2O3 aggregate with particle size of 1-3mm and AL2O3 content ≥70, 32.5% AL2O3 aggregate with particle size of 3-8 and AL2O3 content ≥70, 21.75% 200 mesh alumina fine powder, 4% ultrafine activated alumina powder with α-alumina powder content >99%, 2% kyanite powder, 5% silica powder with purity >93% and flow value >10, 0.2% sodium tripolyphosphate, 0.05% expanded fiber, and 2% No. 80 pure calcium aluminate cement.

2. The construction method of the ultra-low cement corundum castable according to claim 1, characterized in that: The following steps are involved: (1) preparing the ingredients according to the formula of claim 1; (2) Prepare purified water according to drinking water standards; (3) First, pour Al2O3 aggregate, 200 mesh aluminum oxide powder, ultrafine activated alumina powder with an α-alumina powder content of >99%, kyanite powder, silica powder with a purity of >93% and a flow value of >10, sodium tripolyphosphate, expanded fiber, and No. 80 pure calcium aluminate cement into a mixer and dry mix for 2 to 3 minutes, then add 1 to 5% by weight of the above ingredients of purified water, wet mix for 4 to 6 minutes, and the mixer speed is greater than 25 rpm; (4) After the ingredients are mixed, they should be put into construction immediately and used within 30 minutes; (5) After the construction is completed, the surface of the construction body is initially solidified and naturally dried for 24 hours; (6) Repair the surface of the construction body immediately after demolding; (7) Bake according to the oven curve.