A raw material processing technology for castable refractory

Abstract

This invention relates to the field of castable technology, specifically to a raw material processing technology for castables. After bauxite arrives at the site, it is purified by rinsing with a mixed solution made of sodium bicarbonate and water. Then, the bauxite is left to ferment for at least six months. The mixed solution reacts with the calcium oxide and calcium hydroxide generated in the bauxite to produce calcium carbonate. After fermentation, the bauxite is sieved to remove the calcium carbonate. Finally, the sieved bauxite is dried to obtain the raw material that meets the requirements, thus achieving the purpose of removing impurities from the raw material.

Description

Technical Field

[0001] This invention relates to the field of castable technology, and more specifically to a raw material processing technology for castables. Background Technology

[0002] Bauxite is one of the main raw materials for castables. Raw bauxite ore is associated with limestone (CaCO3), which turns into calcium oxide (CaO) after sintering. When used in castables, calcium oxide is prone to causing bridging, cracking, and pulverization. Calcium oxide reacts with water to form calcium hydroxide (Ca(OH)2). Calcium hydroxide is alkaline and has a certain accelerating effect on cement setting. Excessive calcium hydroxide can cause flash setting in the castable, affecting the product's usability.

[0003] Furthermore, the calcium element in the material also has a significant impact on the high-temperature performance of the product. At high temperatures, CaO reacts with aluminum and silicon in the matrix to form anorthite (CaAl2Si2O8), which shrinks after firing, thus affecting the product's usability. The presence of anorthite also adversely affects the product's high-temperature flexural strength, load softening temperature, and other hot-state properties. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a raw material processing technology for castables to remove calcium products from bauxite that affect the performance of castables.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a raw material processing technology for castables, comprising the following steps:

[0006] S1. After the bauxite arrives at the site, it is purified by rinsing with a mixed solution made of sodium bicarbonate and water.

[0007] S2, let the bauxite sit and digest for at least six months;

[0008] S3. After the bauxite has been left to sit and digest, it is sieved to remove small particles or fine powder. The remaining bauxite that meets the particle size requirements is then sorted to remove any impurities.

[0009] S4 involves drying the bauxite from step S3 to obtain raw materials that meet the requirements.

[0010] As an optional option, in step S1, the ratio of sodium bicarbonate to water is 1:3.

[0011] As an optional option, in step S1, the moisture content of the bauxite is ≤0.8%.

[0012] As an optional step, a vibrating sluice screen is used in step S3 to sieve the bauxite after it has been allowed to simmer. Using a vibrating sluice screen can better remove small particles or powder of calcium carbonate.

[0013] Compared with the prior art, the present invention has the following advantages: After rinsing and purifying bauxite with a mixed solution made of sodium bicarbonate and water, it is then left to ferment for at least six months. The water in the mixed solution reacts with the calcium oxide in the bauxite to produce calcium hydroxide, which then reacts with sodium bicarbonate to produce calcium carbonate. Since the calcium carbonate produced is in fine powder form, it can be removed by sieving the bauxite. Calcium oxide, calcium hydroxide, and other calcium products in the bauxite are removed, thereby avoiding any impact on the final quality of the castable and eliminating any adverse effects on the castable. Attached Figure Description

[0014] Figure 1 This is a comparative experimental diagram showing products made from raw materials containing calcium hydroxide and products made from raw materials after adding sodium bicarbonate to remove calcium hydroxide. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0016] A raw material processing technology for castable refractory includes the following steps:

[0017] S1, a mixed solution is prepared by mixing sodium bicarbonate and water in a 1:3 ratio; bauxite is selected, preferably bauxite with a moisture content of ≤0.8%; after the bauxite arrives on site, it is purified by rinsing with the mixed solution.

[0018] S2, bauxite should be left to digest for at least six months to ensure that the mixed solution and bauxite are completely digested.

[0019] After bauxite is sintered, the limestone in it will form calcium oxide. During the process of rinsing and purifying the bauxite with water and during the process of letting the bauxite sit and digest, the water in the mixed solution reacts with the calcium oxide to form calcium hydroxide. The calcium hydroxide then reacts with the sodium bicarbonate in the mixed solution to form calcium carbonate. The calcium carbonate formed is in the form of small particles. In subsequent steps, the bauxite is sieved to remove the calcium carbonate.

[0020] Figure 1The diagram shows a comparative experiment between products made from raw materials containing calcium hydroxide and products made from raw materials treated with sodium bicarbonate to remove calcium hydroxide. After adding water, the flow value of the product made from raw materials containing calcium hydroxide changed significantly around 30 minutes, and flash condensation frequently occurred, resulting in a decrease in flow value. In contrast, the flow value of the product made from raw materials treated with sodium bicarbonate to remove calcium hydroxide did not change significantly. This indicates that by using sodium bicarbonate to react with calcium hydroxide, the state of the castable can be maintained and flash condensation can be effectively avoided.

[0021] S3. The bauxite that has been left to sit and digest is sieved. The purpose of sieving is to remove small particles or powder of calcium carbonate generated during digestion. The sieved bauxite also needs to be sorted to remove impurities and ensure the purity of the final raw material.

[0022] In a preferred embodiment, a vibrating sieve is used to sieve the bauxite in this step. The use of a vibrating sieve is beneficial for fully removing small calcium carbonate particles or calcium carbonate powder.

[0023] S4 involves drying the bauxite processed in step S3 to obtain the raw material that meets the requirements. Calcium oxide, calcium hydroxide, and other calcium-containing products in this raw material are removed, effectively ensuring the quality of the castable.

[0024] In this specification, the terms "an embodiment," "example," "specific example," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0025] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A raw material handling process for a castable, characterized by: It comprises the following steps: S1, after bauxite is brought in, a mixed solution prepared by mixing sodium bicarbonate and water is used to leach and purify the bauxite; S2, the bauxite is left to digest for at least six months; S3, the bauxite after digestion is sieved to remove small particles or fine powder, and the remaining bauxite meeting the particle size requirement is selected to remove impurities; S4, the bauxite after S3 is dried to obtain raw materials meeting the requirements; In S1, the ratio of sodium bicarbonate to water is 1:3; In S1, the water content of bauxite is ≤0.8%; In S3, a vibrating sieve is used to sieve the bauxite after digestion.

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