KR20180029782A - The manufacturing method of the vaterite type calcium carbonate - Google Patents

Abstract

The present invention provides a method for manufacturing vaterite type calcium carbonate, comprising the following steps: supplying sodium hydroxide into a solution containing calcium ions and controlling the solution supplied with sodium hydroxide to have pH value of 12-13; and supplying a gas containing carbon dioxide to the solution supplied with sodium hydroxide and agitating the solution to control final pH to 8.5-9.5 after agitating to manufacture vaterite type calcium carbonate. According to the method, the vaterite type calcium carbonate, which is used as inkjet dyes of high cost, can be manufactured from industrial byproducts of low cost, and no further additives or solutes are required while manufacturing the vaterite type calcium carbonate, thereby having an economical effect due to low cost for a process operation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a bariumite type calcium carbonate,

The present invention relates to a process for the preparation of a vartite-type calcium carbonate from industrial by-products.

Carbon Capture Utilization and Storage (CCUS) refers to CO2 capture technology and technologies that utilize or store it. In recent years, due to the geographical or environmental issues, it is becoming more and more difficult to store large amounts of carbon dioxide, so research and development are being actively carried out on technologies that utilize the captured carbon dioxide as a substitute for the technology for storing captured carbon dioxide . Among them, mineral carbonation technology is attracting attention as a technique to store carbon dioxide generated in a large amount in a industrial site stably and permanently.

Mineral carbonation proceeds through the steps of securing the raw material, carbonation, and product separation. Among the inorganic carbonates, PCC (Precipitated Calcium Carbonate) has a domestic market of 150,000 tons / year and is used in various fields such as paper, rubber, plastic, paint / coating, adhesive / sealant. Such calcium carbonate includes calcite, aragonite and vaterite. Of these, vaterite is a hydrophilic substance having a large specific surface area of porosity. It is an expensive inkjet dye than the other two types of calcium carbonate. It is widely used.

On the other hand, studies have been carried out to produce a bariumite-type calcium carbonate using calcium chloride (CaCl ₂ ) or calcium acetate (Ca (CH ₃ COO) ₂ ) as raw materials. However, the necessity of expensive raw materials and the use of additional additives have.

The present invention aims to provide a method for producing a vatellite-type calcium carbonate for use as an expensive ink-jet dye from low-cost industrial by-products.

According to an embodiment of the present invention, there is provided a method for controlling a pH of a solution to which sodium hydroxide is supplied by supplying sodium hydroxide to a calcium ion-containing solution and controlling the pH of the solution to 12 to 13 and supplying a carbon dioxide- And controlling the final pH after stirring to 8.5 to 9.5 to produce bariumite-type calcium carbonate. The present invention also provides a method for producing bariumite-type calcium carbonate.

And recovering the calcium ion-containing solution by eluting calcium ions from industrial by-products containing calcium by using an eluent.

The concentration of the eluent may be 0.5 to 2M.

The weight ratio of industrial byproducts to the eluent may be 0.01 to 0.1.

The eluent is a hydrogen chloride (HCl), nitric acid (HNO _3), sulfuric acid (H ₂ SO _4), acetic acid (CH ₃ COOH), ammonium nitrate (NH ₄ NO _3), ammonium acetate (CH ₃ COONH _4), ammonium chloride (NH ₄ Cl) and an aqueous solution of ammonium nitrate (NH ₄ NO ₃ ).

The industrial by-products may be at least one selected from the group consisting of steel slag, fly ash, bottom ash, fly ash, waste cement, waste concrete, and paper sludge.

The carbon dioxide-containing gas may be at least one selected from the group consisting of FOG, FINEX off gas, FINT tail gas, BFG (blast furnace gas), converter gas, coal power plant exhaust gas, , Glass-dissolved flue gas, thermal facility flue gas, petrochemical process flue gas, petrochemical process gas, post-combustion flue gas, and gasifier flue gas.

According to one embodiment of the present invention, there is an effect of producing a vatellite-type calcium carbonate used as an expensive inkjet dye from low-cost industrial by-products.

In addition, the method of producing bariumite-type calcium carbonate of the present invention is economically effective because it does not require an additive or a solvent additionally, and the process operation cost is low.

FIG. 1 is a graph showing a change in calcium ion elution efficiency according to the concentration of the eluent. FIG.
FIG. 2 is a graph showing a change in calcium ion elution efficiency depending on the weight ratio of industrial by-products to the eluent. FIG.
FIG. 3 is a graph showing changes in XRD pattern according to a final pH change of calcium carbonate produced by carbonating eluted calcium ions. FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to various embodiments. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.

More particularly, the present invention relates to a process for producing bariumite-type calcium carbonate from industrial by-products, and more particularly, to a process for producing bariumite-type calcium carbonate from industrial by- Type calcium carbonate.

According to an embodiment of the present invention, there is provided a method for controlling a pH of a solution supplied with sodium hydroxide by supplying sodium hydroxide to a calcium ion-containing solution and controlling the pH of the solution to 12 to 13, And controlling the final pH after stirring to 8.5 to 9.5 to produce bariumite-type calcium carbonate. The present invention also provides a method for producing bariumite-type calcium carbonate.

The calcium ion-containing solution can be prepared by a method of eluting calcium ions from industrial by-products containing calcium. Specifically, when an industrial by-product containing the calcium is supplied to an eluent, for example, an ammonium chloride aqueous solution and then stirred, calcium ions are eluted from the industrial by-product. When the substance from which the calcium ions are eluted is subjected to solid-liquid separation, the supernatant in which the calcium ions are dissolved can be recovered. The supernatant solution in which the calcium ions are dissolved corresponds to the calcium ion-containing solution.

On the other hand, the calcium-containing industrial by-products are generated in an industrial process such as a steelmaking process and are not particularly limited as long as they are calcium-containing materials. However, for example, steel-containing slag, coal fly ash, bottom ash, fly ash, waste cement, Sludge (Paper Sludge) may be selected from the group. Accordingly, the present invention not only recycles resources by producing calcium carbonate using waste industrial byproducts, but also does not require additional after-treatment of industrial by-products, which is advantageous from the environmental viewpoint.

For example, the leaching agent for eluting calcium ions from the industrial byproduct may be hydrochloric acid (HCl), nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), sulfuric acid An aqueous solution of acetic acid (CH ₃ COOH), ammonium nitrate (NH ₄ NO ₃ ), ammonium acetate (CH ₃ COONH ₄ ), ammonium chloride (NH ₄ Cl), and ammonium nitrate (NH ₄ NO ₃ ) Or more.

When calcium ions are eluted from industrial byproducts, the concentration of the eluent may be 0.5 to 2M, more preferably 1 to 2M. If the concentration of the eluent is less than 0.5M, the elution efficiency for eluting calcium ions from the industrial by-products is remarkably low, so that the calcium ion concentration of the supernatant may be very low. On the other hand, when the concentration of the eluent exceeds 2M, the pH is lowered, and a large amount of buffer solution for the carbonation reaction is required, and the use of an excessive eluting agent separates the unreacted eluent and the additional cost Or the production of by-products by side reaction with a solvent may occur.

The weight ratio of the industrial byproduct to the solvent may be 0.01 to 0.1, more preferably 0.02 to 0.05. If the weight ratio of the industrial byproduct to the solvent is less than 0.01, the amount of the raw material that can be treated with a certain eluting agent, that is, the amount of the industrial byproduct is too small, On the other hand, when the weight ratio is more than 0.1, the amount of raw materials that can be treated with a certain eluting agent is too much, so that sufficient inactivation of the industrial by-product and the eluting agent can not be achieved. Thus, the elution efficiency of calcium ions is significantly lowered, The concentration may be very low.

According to an embodiment of the present invention, sodium hydroxide is supplied to the calcium ion-containing solution. The sodium hydroxide is supplied as a pH adjusting agent. Specifically, since sodium hydroxide is supplied, carbon dioxide supplied in the subsequent step of producing bariumitic calcium carbonate is converted into carbonate ion (CO ₃ ^2- ) in the solution . Since the carbon dioxide is maintained in the form of carbonate ion in the solution, the generation of calcium carbonate can be facilitated by the reaction between the carbonate ion and the calcium ion. On the other hand, it is preferable to control the pH of the solution to 12 to 13 when sodium hydroxide is supplied. If the pH is not in the range of 12 to 13, the carbonate may be maintained in the form of bicarbonate ion (HCO ₃ ^- ) rather than carbonate ion (CO ₃ ^2- ) to lower the conversion to calcium carbonate.

The carbon dioxide-containing gas is supplied to the solution to which the sodium hydroxide is supplied and stirred to produce the bariumite-type calcium carbonate. At this time, the final pH of the solution supplied with the carbon dioxide-containing gas and stirred is preferably controlled to 8.5 to 9.5. When the final pH of the stirred solution satisfies 8.5 to 9.5, the bariumite-type calcium carbonate is dominantly produced. On the other hand, when the final pH of the stirred solution does not satisfy 8.5 to 9.5, Site type is dominantly generated.

On the other hand, the type of the carbon dioxide-containing gas supplied to the solution is not particularly limited, and examples thereof include pure carbon dioxide, FINO off gas, FINT tail gas, (BFG, blast furnace gas), converter gas, coal power plant flue gas, gas plant flue gas, incinerator flue gas, glass fired flue gas, thermal equipment flue gas, petrochemical process flue gas, petrochemical process gas, Lt; / RTI >

Hereinafter, the present invention will be described more specifically by way of specific examples. The following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

Example

1. Calcium ion elution efficiency change according to concentration of eluent

0.1 g of an ammonium chloride aqueous solution as an eluent was supplied to 1 g of steelmaking slag, stirred for 90 minutes at a stirring speed of 300 rpm at room temperature, and then the supernatant (calcium ion-containing solution) was recovered. At this time, the concentration of the ammonium chloride aqueous solution was controlled to 0.5, 1.0, 1.5, or 2.0 M, respectively, and the calcium ion elution efficiency was measured according to the concentration of the ammonium chloride aqueous solution. The content of the calcium ions was measured by ICP (Inductively Coupled Plasma), and the results are shown in FIG.

According to FIG. 1, as the concentration of the eluent was increased, the calcium ion elution efficiency was increased. However, when the eluent concentration was over 0.5M, the rate of increase was remarkably decreased and the elution efficiency was more than 60%.

2. Calcium ion elution efficiency change according to the weight ratio of industrial by-products to the eluent

0.1 L of a 2 M ammonium chloride aqueous solution as an eluting agent was supplied to the steelmaking slag, stirred at room temperature for 300 minutes at a stirring speed of 90 rpm, and then the supernatant (calcium ion-containing solution) was recovered. At this time, the slag / liquid ratio of the steel slag to the aqueous ammonium chloride solution was controlled to 0.01, 0.013, 0.02, 0.025, 0.033, 0.05 and 0.1, and the calcium ion elution efficiency was measured according to the weight ratio . The content of the calcium ion was measured by ICP (Inductively Coupled Plasma), and the results are shown in FIG.

According to FIG. 2, as the weight ratio (slag / liquid) increases, the elution efficiency decreases gradually, but when the ratio is more than 0.05, the elution efficiency decreases sharply.

3. XRD Pattern Change of Calcium Carbonate with Final pH Change after Stirring

0.5 g of a 2 M ammonium chloride aqueous solution as an eluent was supplied to 10 g of steelmaking slag, stirred at room temperature for 300 minutes at a stirring speed of 90 rpm, and then the supernatant (calcium ion-containing solution) was recovered. Sodium hydroxide was added to the supernatant to raise the pH to 13, and 300 sccm of carbon dioxide was supplied and stirred. After stirring, the final pH was controlled to be 7.7, 8, 9, or 10. At this time, the precipitated calcium carbonate was recovered, dried and analyzed by X-ray diffraction spectroscopy (XRD). The results are shown in Fig.

According to FIG. 3, only the calcite-type calcium carbonate was produced when the final pH was 7.7, 8, or 10 after stirring, but it was confirmed that the calcined calcium carbonate was dominantly formed when the pH was 9.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be obvious to those of ordinary skill in the art.

Claims (7)

Supplying sodium hydroxide to the calcium ion-containing solution to control the pH of the solution supplied with sodium hydroxide to 12 to 13; And
And a step of supplying carbon dioxide-containing gas to the solution to which the sodium hydroxide is supplied and stirring to control the final pH after stirring to 8.5 to 9.5 to produce bariumite-type calcium carbonate.
The method according to claim 1, wherein the calcium ion-containing solution is prepared by eluting calcium ions from industrial by-products containing calcium by using an extraction agent.
The method according to claim 2, wherein the leaching agent has a concentration of 0.5 to 2M.
3. The process for producing a bacteriocidal calcium carbonate according to claim 2, wherein the weight ratio of the industrial byproduct to the emulsion is from 0.01 to 0.1.
The method of claim 2 wherein the eluent is a hydrogen chloride (HCl), nitric acid (HNO _3), sulfuric acid (H ₂ SO _4), acetic acid (CH ₃ COOH), ammonium nitrate (NH ₄ NO _3), ammonium acetate (CH ₃ (NH ₄ Cl), and ammonium nitrate (NH ₄ NO ₃ ), in an aqueous solution of at least one selected from the group consisting of COONH ₄ , COONH ₄ , ammonium chloride (NH ₄ Cl) and ammonium nitrate (NH ₄ NO ₃ ).
The method according to claim 2, wherein the industrial byproduct is at least one selected from the group consisting of iron-based slag, coal fly ash, bottom ash, fly ash, waste cement, waste concrete and paper sludge.
The method of claim 1, wherein the carbon dioxide-containing gas is at least one selected from the group consisting of FOG, FINEX off gas, FINT tail gas, blast furnace gas, converter gas, coal- Wherein the at least one selected from the group consisting of gas power plant exhaust gas, incinerator exhaust gas, glass melting exhaust gas, thermal facility exhaust gas, petrochemical process exhaust gas, petrochemical process gas, post combustion exhaust gas and gasifier exhaust gas.

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