KR20220081575A - Colored concrete composition using red mud - Google Patents

Abstract

The present invention relates to a colored concrete composition using red mud, and more particularly, sand and red pigment, which are aggregate materials used in the production of colored concrete by recycling red mud, a bauxite residue treated as a filling agent or industrial waste. By replacing iron phosphate, it relates to a color concrete composition capable of reducing manufacturing cost and preventing environmental pollution problems.

Description

Colored concrete composition using red mud}

The present invention relates to a colored concrete composition using red mud, and more particularly, sand and red pigment, which are aggregate materials used in the production of colored concrete by recycling red mud, a bauxite residue treated as a filling agent or industrial waste. By replacing iron phosphate, it relates to a color concrete composition capable of reducing manufacturing cost and preventing environmental pollution problems.

The aluminum hydroxide manufacturing process is based on the Bayer process, which is divided into a pulverization and desiliconization process, an elution process, a purification process, a precipitation process, and a classification process.

In the pulverization and desiliconization process, since bauxite has different properties and properties depending on the region where it is produced, it is pulverized to 200 μm, and then the silicon component contained in the pulverized bauxite is removed.

On the other hand, the reason for removing silicon is that the reaction temperature of silicon is low, so it is easily dissolved during the process and flows into the final product, aluminum hydroxide, to lower the purity and form scale in pipes or equipment.

The elution process includes a process for extracting alumina from bauxite.

The elution temperature condition varies depending on the chemical composition of the input bauxite. Gibbsite elutes at a relatively low temperature, whereas bamite elutes at a high temperature and diaspore elutes at a higher temperature.

Here, sodium hydroxide is added to bauxite, and heating and pressurization to 200-400° C. are included.

At this time, 1 to 2 tons of redmud, a bauxite residue, is generated in the production of 1 ton of aluminum hydroxide, and about 280,000 to 300,000 tons are generated annually.

The purification process includes the process of separating solids and liquids between the sodium aluminate solution dissolved in the elution process and the insoluble residue.

This process is to separate the supersaturated sodium aluminate solution from the precipitation tank, send only the clear liquid to the next precipitation process, and to recover the expensive caustic soda.

In the precipitation process, a process solution containing a lot of alumina is added to seeds to promote particle growth and cooled to precipitate aluminum hydroxide in a sedimentation tank.

The precipitation process aims to produce a product with desired output, quality, and particle size distribution, and the impurity content varies during this process.

The sorting process involves sorting the finished product by particle size.

To classify this, wet cyclone or multi-stage sedimentation tank is used, and the fine particles that are disadvantaged in the first stage are used as seeds, and the coarser particles in the next stage are classified as manufactured products.

In general, two kinds of seeds (Fine and Coarse seed) and two kinds of products (Normal and Coarse product) are produced.

Red mud, a process waste, contains 10 to 15% aluminum, 25 to 40% iron, 5 to 10% sodium, and 1 to 5% titanium, and is very viscous with a moisture content of 35 to 45%. .

In addition, it is a red color similar to the expensive iron oxide used as a pigment in the color concrete composition, and since landfill is impossible due to strong alkalinity, there are many difficulties worldwide in treating red mud.

Conventional treatment techniques include a method of treating with embankment material or industrial waste, or mixing red mud with cement to harden it to some extent and then dumping it into the sea, adding water to make a fluid slurry, and then sinking it into the deep sea through a pipe. It is a general treatment method.

However, these treatment methods are expensive, adversely affect the environment, and require a lot of recycling, use and maintenance costs.

In addition, iron oxide, which is a pigment of conventional colored concrete, is subjected to a separate heat treatment in order to express red color.

The present invention has been devised to solve a constant problem, and an object of the present invention is to recycle red mud, a bauxite residue, to replace iron oxide, which is a pigment in color concrete, thereby providing an environmentally and economically excellent color concrete composition. will be.

On the other hand, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention provides a color concrete composition comprising a mixture comprising cement, admixture, gravel and red mud.

In a preferred embodiment, the mixture further comprises an admixture.

In a preferred embodiment, the admixture uses any one selected from the group consisting of fly ash, blast furnace slag fine powder and silica fume.

In a preferred embodiment, the admixture uses any one selected from the group consisting of AE admixtures, quick-setting agents, fluidizing agents, water reducing agents and retarders.

In a preferred embodiment, the mixture consists of 100 to 130 parts by weight of admixture, 140 to 160 parts by weight of cement, 260 to 280 parts by weight of red mud, and 350 to 390 parts by weight of gravel.

In a preferred embodiment, the admixture is added in an amount of 1% to 5% based on the weight of the mixture.

In a preferred embodiment, the red mud has a moisture content of 20% to 45% and an iron oxide component of 40% or more.

The present invention has the following excellent effects.

According to the color concrete composition of the present invention, it is possible to prevent environmental pollution problems and reduce manufacturing costs by using red mud as an alternative resource for iron oxide, which is an expensive pigment used in manufacturing conventional colored concrete products, and sand, which is an aggregate material. It has the advantage that it can bring excellent environmental and economic advantages.

As for the terms used in the present invention, general terms that are currently widely used are selected, but in specific cases, there are also terms arbitrarily selected by the applicant. should be taken into account to understand its meaning.

Hereinafter, the technical configuration of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

The color concrete composition of the present invention is composed of a mixture including cement, admixture, gravel and red mud.

That is, the color concrete composition of the present invention is characterized by using red mud by replacing sand and iron oxide, unlike the existing color concrete composition containing cement, admixture, gravel, sand and iron oxide.

In addition, the concrete product manufactured using the color concrete composition of the present invention has a red color, and the concrete product having various chroma according to the iron oxide content, which is the main component of the red mud, can be manufactured.

In addition, the concrete product can be used as a construction material such as Lego blocks, fish farms, fish blocks, reinforced soil blocks, special blocks, etc..

In addition, the mixture is preferably mixed in 90 to 140 parts by weight of admixture, 130 to 170 parts by weight of cement, 250 to 290 parts by weight of red mud, and 340 to 400 parts by weight of gravel.

More preferably, the mixture is mixed with 100 to 130 parts by weight of an admixture, 140 to 160 parts by weight of cement, 260 to 290 parts by weight of red mud, and 340 to 400 parts by weight of gravel.

In addition, the cement may be one or more mixed cements selected from portland cement, slag cement, alumina cement, and super-velocity cement, preferably Portland cement.

It is preferable to use any one selected from the group consisting of fly ash, blast furnace slag fine powder, and silica fume as the admixture, and more preferably, fly ash may be used as the admixture.

The red mud is a bauxite residue generated during the production of aluminum hydroxide, and preferably has a moisture content of 3% to 10%, more preferably 20% to 45%.

In addition, it is preferable to use the red mud containing 30% or more of the iron oxide component in order to express red color, and more preferably, use the iron oxide component containing 40% or more.

In addition, the red mud can be neutralized using an acidic substance such as acetic acid, sulfuric acid, hydrochloric acid, etc. so that the strong alkaline component has a certain level of concentration (ph), thereby suppressing the whitening of the red mud.

In addition, it is preferable to use the gravel having a maximum size of 13mm to 25mm.

In addition, gravel of various sizes may be used as the gravel according to the required strength, and the type is not limited.

In addition, the color concrete composition of the present invention may be configured by further adding an admixture to the mixture.

Here, the admixture may be added in an amount of 0.5% to 5% based on the weight of the mixture, more preferably 1% to 5% based on the weight of the mixture.

In addition, the admixture may use any one selected from the group consisting of an AE admixture, a quick-setting agent, a fluidizing agent, a water reducing agent, and a retarder, and the type is not limited.

<Experimental example> Comparative Example and Example Compressive Strength Comparison

In order to evaluate the performance of the concrete composition using the red mud of the present invention, concrete products (comparative examples, examples) were prepared by mixing as shown in Tables 1 and 2 below.

division cement sand gravel (25mm) comparative example 1 (150 kg) 2.6 (390 kg) 2.5 (375 kg)

division cement fly ash red mud gravel (25mm) Example 1 (150 kg) 0.78 (117 kg) 1.82 (273 kg) 2.5 (375 kg)

Referring to Table 1, in the case of Comparative Example, standard concrete was prepared by mixing cement in a ratio of 1, sand 2.6, and gravel (25mm) 2.5. Color concrete was prepared by mixing mud at a ratio of 1.82 and gravel (25mm) of 2.5. As a result of measuring the compressive strength of the comparative examples and examples, it was found that the comparative example had a compressive strength of 210 kpa, and the example had a compressive strength of 230 kpa to 250 kpa. It was confirmed that it has compressive strength.

Accordingly, it was found that when colored concrete was manufactured using the concrete composition using red mud of the present invention, the compressive strength was superior to that of conventional concrete, and the color of colored concrete could be controlled by controlling the content of fly ash and red mud. There are advantages.

In addition, the present invention has the advantage of preventing environmental pollution problems and reducing manufacturing costs by using red mud as an alternative resource to iron oxide, which is an expensive pigment used in manufacturing conventional colored concrete products, and sand, which is an aggregate material. have.

As described above, the present invention has been illustrated and described with reference to preferred embodiments, but it is not limited to the above-described embodiments, and those of ordinary skill in the art to which the present invention pertains within the scope not departing from the spirit of the present invention Various changes and modifications will be possible.

Claims (7)

Color concrete composition comprising a mixture comprising cement, admixture, gravel and red mud
The method of claim 1,
Color concrete composition, characterized in that the mixture further comprises an admixture The method of claim 1,
The color concrete composition, characterized in that the admixture uses any one selected from the group consisting of fly ash, blast furnace slag fine powder and silica fume. 3. The method of claim 2,
The admixture is a color concrete composition, characterized in that any one selected from the group consisting of AE admixtures, quick-setting agents, fluidizing agents, water reducing agents and retarders is used. The method of claim 1,
The mixture is 100 to 130 parts by weight of admixture, 140 to 160 parts by weight of cement, 260 to 280 parts by weight of red mud, and 350 to 390 parts by weight of gravel. 3. The method of claim 2,
Color concrete composition, characterized in that the admixture is added in an amount of 1% to 5% based on the weight of the mixture The method of claim 1,
The red mud color concrete composition, characterized in that it has a moisture content of 20% to 45% and an iron oxide component of 40% or more