KR102406342B1 - Hemihydrate gypsum and manufacturing method there of - Google Patents

Abstract

Hemihydrate gypsum according to an aspect of the present invention contains 40 wt% to 80 wt% of dihydrate gypsum and 20 wt% to 60 wt% of a mixture containing anhydrite and quicklime as main components, , in the mixing step and mixing step of mixing 40 wt% to 80 wt% of the dihydrate gypsum prepared in the preparation step and preparing the dihydrate gypsum and 20 wt% to 60 wt% of the mixture agent having anhydrite and quicklime as main components It includes a dehydration step of dehydrating a part of the adhering moisture and crystalline moisture of the dihydrate gypsum through the mixed agent.

Description

Hemihydrate gypsum and manufacturing method thereof

The present invention relates to hemihydrate gypsum and a method for preparing the same.

Hemihydrate gypsum has been used as a frame (profile) to repeatedly produce ceramics of the same shape in the 1950s, and is now a material that greatly contributes to the cement industry and the electronic material industry.

This hemihydrate gypsum can be manufactured by a relatively simple manufacturing method of dehydrating a part of the attached and crystalline water of the dihydrate gypsum by applying heat to the dihydrate gypsum, making mass production possible through a fuel with high thermal efficiency. The manufacturing method has been disclosed in Korean Patent Publication No. 10-0443246 (application date: 2011.10.29., announcement date: 2004.07.26., hereinafter referred to as 'prior art').

However, in the prior art, as the use of fuel is inevitable in the step of applying heat to gypsum dihydrate, there is a problem in that the manufacturing cost also increases according to the amount of fuel used.

In addition, when manufacturing hemihydrate gypsum using the prior art, if the fuel consumption is reduced in order to reduce the cost, or if a fuel with low thermal efficiency is used, there is a problem that the performance of the hemihydrate gypsum may also be reduced.

An object of the present invention is to provide a hemihydrate gypsum manufacturing technology capable of maintaining performance while reducing manufacturing cost in order to solve the above problems.

Hemihydrate gypsum according to a preferred embodiment of the present invention, 40 wt% to 80 wt% of dihydrate gypsum; and 20 wt% to 60 wt% of a mixture containing anhydrite and quicklime as main components, wherein the mixture is mixed with the dihydrate gypsum and adheres moisture and crystal moisture of the dihydrate gypsum through heat of slaking It is characterized in that a portion of the dehydrated.

Here, the dihydrate gypsum is characterized in that it is prepared by mixing any one or two or more of flue gas desulfurization gypsum, phosphate byproduct gypsum, titanium byproduct gypsum, and natural gypsum.

In addition, the mixture is characterized in that it is prepared as a circulating fluidized bed fly ash, which is a by-product of the deoiling process of a heavy oil/lime combustion boiler.

On the other hand, the method for producing hemihydrate gypsum according to a preferred embodiment of the present invention includes a preparation step of preparing a mixture containing anhydrite and quicklime as main components and dihydrate gypsum; A mixing step of mixing the gypsum dihydrate in an amount of 40 wt% to 80 wt% and the mixing agent in an amount of 20 wt% to 60 wt%; and a dehydration step of dehydrating a portion of the adhering moisture and crystalline moisture of the dihydrate gypsum.

Here, the mixing step is characterized in that it is a step of preparing a dihydrate gypsum in which any one or two or more of flue gas desulfurization gypsum, phosphate byproduct gypsum, titanium byproduct gypsum, or natural gypsum is mixed.

In addition, the preparation step is characterized in that it is a step of preparing a mixture prepared from circulating fluidized bed fly ash, which is a by-product of the deoiling process of a heavy oil/lime combustion boiler.

And, the dehydration step, the circulating fluidized bed fly ash mixed with the dihydrate gypsum in the mixing step is a step of dehydrating a part of the adhering moisture and crystalline moisture of the dihydrate gypsum through heat of slaking. do.

On the other hand, in the dehydration step, only when the mixing ratio of the gypsum dihydrate in the mixing step is 60 wt% or more, auxiliary heat is generated through auxiliary fuel containing at least any one of heavy oil, coal, gas, or waste heat gas. , characterized in that it is a step of dehydrating some of the adhering moisture and crystalline moisture of the dihydrate gypsum through auxiliary heat and heat of slaking of the circulating fluidized bed fly ash mixed with the dihydrate gypsum.

In the hemihydrate gypsum according to a preferred embodiment of the present invention, since the quicklime component contained in the circulating fluidized bed fly ash mixed together dehydrates the adhering moisture and crystalline moisture of the dihydrate gypsum, for the production of hemihydrate gypsum, the adhering moisture and It is possible to exclude the use of fuel for dehydrating the crystal water, and even if the use of fuel is required, it is used less than before, so it has the effect of significantly reducing the manufacturing cost of hemihydrate gypsum.

In addition, in the hemihydrate gypsum according to a preferred embodiment of the present invention, as the anhydrite component contained in the circulating fluidized bed fly ash mixed with the dihydrate gypsum is a gypsum material of the same type as the hemihydrate gypsum, it does not stop at simply reducing the manufacturing cost, There is also the effect of improving the performance of hemihydrate gypsum.

1 shows a method for manufacturing hemihydrate gypsum according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the hemihydrate gypsum of the present invention and its manufacturing method will be described in detail with reference to the accompanying drawings.

Like reference numerals in each figure indicate like elements. In addition, specific structural or functional descriptions for the embodiments of the present invention are only exemplified for the purpose of describing the embodiments according to the present invention, and unless otherwise defined, all terms used herein, including technical or scientific terms They have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. It is preferable not to

[Hemihydrate gypsum according to a preferred embodiment of the present invention.]

Hemihydrate gypsum according to a preferred embodiment of the present invention may include dihydrate gypsum and a mixture.

), 배연탈황석고, 인산부산석고, 티타늄부산석고 또는 천연석고 중 어느 하나 또는 둘 이상이 혼합되어 마련될 수 있다.Dihydrate gypsum (calcium sulfate dihydrate,

), flue gas desulfurization gypsum, phosphate phosphate gypsum, titanium phosphate gypsum, or any one of natural gypsum or a mixture of two or more may be prepared.

The admixture contains anhydrite and quicklime as main components, and can be prepared as circulating fluidized bed fly ash, a by-product of the deoiling process of a heavy oil/lime combustion boiler. [Table 1] below shows the components of circulating fluidized bed fly ash.

division

)anhydrite
(

) quicklime
(

) uncalcined limestone
(

) Etc
ingredient Circulating Fluidized Bed Fly Ash 34.7% 43.7% 12.2% 9.4%

In a preferred embodiment of the present invention, the use of circulating fluidized bed fly ash, which is a by-product of the deoiling process of a heavy oil/lime combustion boiler, as a mixture to be mixed with dihydrate gypsum to produce hemihydrate gypsum, is as shown in [Table 1] . , to use anhydrite and quicklime, which are the main components of circulating fluidized bed fly ash. Because it is high, it can be used as a fuel that can dehydrate the attached moisture and crystal water of dihydrate gypsum.

The above-mentioned dihydrate gypsum and circulating fluidized bed fly ash can be mixed to produce hemihydrate gypsum. The production of hemihydrate gypsum can be accomplished by mixing 40 wt% to 80 wt% of dihydrate gypsum and 20 wt% to 60 wt% of circulating fluidized bed fly ash, preferably, 50 wt% to 70 wt% of dihydrate gypsum and circulating fluidized bed fly ash. It is preferable to mix 50 wt% to 70% wt% of ash.

) 성분은 아래의 [식 1]과 같이 함께 혼합된 이수석고의 2수화물과 반응하여 소화 열(heat of slaking)을 발생시켜 이수석고의 부착수분과 결정수를 탈수시키게 된다. At this time, quicklime (calcium oxide,

) component reacts with the dihydrate of dihydrate gypsum mixed together as shown in [Equation 1] below to generate heat of slaking to dehydrate the attached moisture and crystal water of dihydrate gypsum.

[Equation 1]

)를 얻을 수 있게 된다. As a result, quicklime, which is the composition of the circulating induced layer fly ash, reacts with the dihydrate of dihydrate gypsum to generate heat (dehydration), and calcium hydroxide is produced. In this process, the dehydration reaction of quicklime generates sufficient heat to dehydrate the adhering moisture and crystal water of dihydrate gypsum.

) can be obtained.

At this time, in the mixture of dihydrate gypsum and circulating fluidized bed fly ash, 40 wt% to 80 wt%, preferably, 50 wt% to 70 wt% of dihydrate gypsum is mixed for the following reasons. In manufacturing hemihydrate gypsum, if the mixing ratio of dihydrate gypsum is reduced, the dehydration temperature increases, but the performance of hemihydrate gypsum decreases. On the other hand, if the mixing ratio of dihydrate gypsum increases, the dehydration temperature decreases (= because the dehydration reaction of crystallized water does not occur smoothly), so hemihydrate gypsum is not manufactured correctly. Therefore, in the production of a preferable hemihydrate gypsum, a mixing ratio of 50 wt% to 70 wt% of dihydrate gypsum should be maintained. The composition of the hemihydrate gypsum prepared at this mixing ratio is shown in [Table 2] below.

division hemihydrate gypsum
(wt%) anhydrite
(wt%) slaked lime
(wt%) total
(wt%) other ingredients
(wt%) A 38.7 18.7 28.9 86.3 13.7 B 48.0 14.9 24.7 87.6 12.4 C 58.2 11.6 19.2 89.0 11.0

Here, A is 50 wt% dihydrate gypsum and 50 wt% circulating fluidized bed fly ash, B is dihydrate gypsum 60 wt% and circulating fluidized bed fly ash 40 wt%, C is dihydrate gypsum 70 wt% and circulating fluidized bed fly ash 30 wt% It is a hemihydrate gypsum prepared in a mixing ratio. The physical performance of the hemihydrate gypsum prepared according to the embodiment of the present invention prepared at the mixing ratio of [Table 2] is shown in [Table 3] below.

division Mixing ratio (wt%) coma
(%)

)compressive strength (

) Lee Soo Gypsum Circulating Fluidized Bed Fly Ash wet strength dry strength A 50 50 63 7 35 B 60 40 63 20 79 C 70 30 64 30 106 commercial product 1 - - 68 3 34 commercial product 2 - - 70 19 87

As can be seen in [Table 3] , when the mixing ratio of the dihydrate gypsum is 50 wt% to 70 wt%, it can be confirmed that the compressive strength is similar to or improved more than that of the commercial product. In particular, it can be seen that the compressive strength is significantly increased when the mixing ratio of the dihydrate gypsum is 70 wt%.

Therefore, hemihydrate gypsum according to a preferred embodiment of the present invention can be prepared by adding a process of applying auxiliary heat to maintain the dehydration temperature above a certain level. As such, the process of applying auxiliary heat is made only when the mixing ratio of the dihydrate gypsum is 60 wt% or more, and as described above, it is to improve the performance of the hemihydrate gypsum and at the same time increase the dehydration temperature of the dihydrate gypsum. In this case, the auxiliary fuel used to apply auxiliary heat may include at least one of heavy oil, coal, gas, and waste heat gas. At this time, hemihydrate gypsum is manufactured by putting dihydrate gypsum and circulating fluidized bed fly ash into a calcining furnace and mixing them, and then applying heat to the calcining furnace through auxiliary fuel. Hereinafter, a method of manufacturing hemihydrate gypsum according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

[Method for producing hemihydrate gypsum according to a preferred embodiment of the present invention.]

1 shows a method for manufacturing hemihydrate gypsum according to a preferred embodiment of the present invention. Referring to FIG. 1, the method for manufacturing hemihydrate gypsum according to a preferred embodiment of the present invention may include a preparation step (S100), a mixing step (S200) and a dehydration step (S300).

The preparation step (S100) is a step of preparing a mixture containing anhydrite and quicklime as main components and dihydrate gypsum. Dihydrate gypsum prepared in this step may be prepared by mixing any one or two or more of flue gas desulfurization gypsum, phosphoric acid gypsum, titanium byproduct gypsum, and natural gypsum, and the mixed agent is a circulating fluidized bed, which is a by-product of the deoiling process of a heavy oil/lime combustion boiler. It may be prepared as fly ash.

The mixing step (S200) is a step of mixing dihydrate gypsum and circulating fluidized bed fly ash according to a preset ratio. At this time, the dihydrate gypsum may be mixed in a mixing ratio of 50 wt% to 70 wt%, and the circulating fluidized bed fly ash may be mixed at a mixing ratio of 30 wt% to 50%, and the dihydrate gypsum and the circulating fluidized bed fly ash may be mixed in the calciner at this mixing ratio. do. At this time, the process of the dehydration step (S300) to be described later may vary depending on whether the dihydrate gypsum is mixed in an amount of 60 wt% or more.

)는 이수석고(황산칼슘 2수화물,

)의 2수화물과 발열반응을 일으키면서 이수석고의 부착수분과 결정수분의 일부를 탈수시킴으로써, 분말형태의 반수석고(황산칼슘 반수화물,

)가 제조되어진다.The dehydration step (S300) is a step of dehydrating a part of the adhering moisture and crystalline moisture of the dihydrate gypsum through the circulating fluidized bed fly ash mixed in the mixing step (S200). At this time, quicklime (calcium oxide,

) is dihydrate gypsum (calcium sulfate dihydrate,

) by dehydrating a part of the adhering and crystalline water of dihydrate gypsum while generating an exothermic reaction with the dihydrate of

) is manufactured.

On the other hand, in the dehydration step (S300), only when the dihydrate gypsum is mixed in 60 wt% or more in the mixing step (S200), a process of applying auxiliary heat may be added. At this time, by heating the calcination furnace through an auxiliary fuel including at least one of heavy oil, coal, gas, or waste heat gas, it is possible to help dehydration of the adhering moisture and crystalline moisture of the dihydrate gypsum. In addition, the dehydration step (S300) may further include a packaging step of packaging the produced hemihydrate gypsum gypsum in a subdivided form.

That is, the hemihydrate gypsum according to a preferred embodiment of the present invention uses the quicklime component contained in the circulating fluidized bed fly ash to dehydrate the adherent and crystalline moisture of the dihydrate gypsum, so the fuel for dehydrating the adherent and crystalline moisture of the dihydrate gypsum The use can be excluded, and even if the use of fuel is required, it has the effect of significantly reducing the manufacturing cost of hemihydrate gypsum because it uses less than the existing ones.

In addition, in the hemihydrate gypsum according to a preferred embodiment of the present invention, as the anhydrite component contained in the circulating fluidized bed fly ash mixed with the dihydrate gypsum is a gypsum material of the same type as the hemihydrate gypsum, it does not stop at simply reducing the manufacturing cost, There is also the effect of improving the performance of hemihydrate gypsum.

The above-described embodiments of the present invention have been disclosed for purposes of illustration, and various modifications, changes, and additions will be possible within the spirit and scope of the present invention by those skilled in the art with respect to the present invention, and such modifications, changes and additions should be regarded as belonging to the following claims.

Claims (8)

50 wt% to 70 wt% of gypsum dihydrate; and
Including; 30 wt% to 50 wt% of a mixture comprising anhydrite and quicklime;
The admixture is mixed with the dihydrate gypsum to dehydrate a part of the adhering water and crystal water of the dihydrate gypsum through heat of slaking,
The mixture is composed of 33wt% to 37wt% of anhydrite, 42wt% to 46wt% quicklime, 10wt% to 14wt% of uncalcined limestone and other components, and circulating fluidized bed fly ash, a by-product of the deoiling process of heavy oil/lime combustion boilers. characterized in that it is provided with
semi-hydrated gypsum.
According to claim 1,
The dihydrate gypsum is characterized in that any one or a mixture of two or more of flue gas desulfurization gypsum, phosphate phosphate gypsum, titanium phosphate gypsum, or natural gypsum is prepared.
semi-hydrated gypsum.
delete It is composed of 33wt% to 37wt% of anhydrite, 42wt% to 46wt% quicklime, 10wt% to 14wt% uncalcined limestone and other ingredients, and is prepared as circulating fluidized bed fly ash, a by-product of the deoiling process of heavy oil/lime combustion boilers. A preparation step of preparing a mixture and dihydrate gypsum;
A mixing step of mixing the mixing agent in an amount of 50 wt% to 70 wt% of the gypsum dihydrate prepared in the preparation step in an amount of 30 wt% to 50 wt%; and
A dehydration step of dehydrating a part of the adhering water and crystal water of the dihydrate gypsum through the mixing agent mixed in the mixing step; characterized in that it comprises a
A method for manufacturing hemihydrate gypsum.
5. The method of claim 4,
The mixing step, characterized in that it is a step of preparing a dihydrate gypsum in which one or two or more of flue gas desulfurization gypsum, phosphate byproduct gypsum, titanium byproduct gypsum, or natural gypsum is mixed.
A method for manufacturing hemihydrate gypsum.
delete 5. The method of claim 4,
The dehydration step is a step of dehydrating a part of the adhering moisture and crystalline moisture of the dihydrate gypsum through the heat of slaking of the circulating fluidized bed fly ash mixed with the dihydrate gypsum in the mixing step.
A method for manufacturing hemihydrate gypsum.
5. The method of claim 4,
In the dehydration step, only when the mixing ratio of the gypsum dihydrate in the mixing step is 60 wt% or more, auxiliary heat is generated through auxiliary fuel containing at least one of heavy oil, coal, gas, or waste heat gas, It is characterized in that it is a step of dehydrating part of the adhering moisture and crystalline moisture of the dihydrate gypsum through heat and heat of slaking of the circulating fluidized bed fly ash mixed with the dihydrate gypsum.
A method for manufacturing hemihydrate gypsum.

Images