KR20100071571A

KR20100071571A - Method for manufacturing titanium carbide

Info

Publication number: KR20100071571A
Application number: KR1020080130340A
Authority: KR
Inventors: 박종일; 정재영
Original assignee: 재단법인 포항산업과학연구원
Priority date: 2008-12-19
Filing date: 2008-12-19
Publication date: 2010-06-29

Abstract

The present invention relates to a titanium carbide production method using an electrolytic reduction technique, M ₁ X (M ₁ is one selected from the group consisting of Ca, Ba, Li and Cs, X is F or Cl) of the molten salt Preparing; And

Obtaining titanium carbide by electrolytic reaction using carbon and titanium dioxide mixture as a cathode in the molten salt

It is made, including.

According to the present invention, the mixture of carbon and titanium dioxide improves the current flow during the electrolytic reduction reaction, thereby quickly producing titanium and reacting with carbon to efficiently obtain titanium carbide from titanium dioxide.

Description

Titanium carbide production method {METHOD FOR MANUFACTURING TITANIUM CARBIDE}

The present invention relates to a method for producing titanium carbide, and more particularly, to a method for producing titanium carbide by electrolytic reduction reaction of a mixture of carbon and titanium dioxide in a molten salt.

The method for producing titanium carbide is obtained by reacting carbon powder and titanium powder at high temperature. This uses a costly titanium powder and there is a problem that it is not economical in terms of manufacturing through high temperature high energy reaction.

Meanwhile, techniques for electrolytic reduction include the following. International Patent PCT / GB99 / 01781, a titanium dioxide reduction technology using molten salt, proposes a method of removing oxygen from electrolytic reduction from metals and metal oxides, and US Pat. No. 5,211,775 uses calcium metal to reduce titanium. The technique to be used is proposed.

Okabe, Oishi and Ono (Mat. Trans B. 23B (1992): 583) also reduce titanium oxides by electrochemical reactions in molten salts of calcium chloride.

However, since the technology for manufacturing titanium carbide using electrolytic reduction has not been disclosed, the development of technology for this is required.

The present invention is to solve the above problems, and to provide a method for producing titanium carbide through the reaction with carbon while reducing the titanium dioxide in the molten salt.

The present invention comprises the steps of preparing a molten salt of M ₁ X (M ₁ is selected from the group consisting of Ca, Ba, Li and Cs, X is F or Cl); And

It provides a titanium carbide production method comprising a.

According to the present invention, it is possible to quickly obtain titanium carbide by an electrolytic reaction of a mixture of carbon and titanium dioxide, thereby quickly preparing titanium carbide (TiC) powder. It is also economical in that no expensive titanium powder is used.

Hereinafter, the present invention will be described in detail.

In the present invention, a method for producing titanium carbide is to produce titanium carbide faster by an electrolytic reduction reaction using a mixture of carbon and titanium dioxide as a cathode. Since the carbon and titanium dioxide mixture is porous as a sintered body, many channels are formed to increase the electrical conductivity in the electrolysis reaction so that the metal titanium powder in the molten salt can be efficiently obtained in a short time. The electrolysis is carried out under the condition that oxygen reacts at the electrode surface of the carbon and titanium dioxide mixed material and oxygen is dissolved in the electrolyte.

In order to prepare the titanium carbide of the present invention, a molten salt of M ₁ X is first prepared.

M ₁ is _one selected from the group consisting of Ca, Ba, Li, and Cs, and X is F or Cl. That is, compounds and mixtures of CaCl ₂ , BaCl ₂ , LiCl or CsCl ₂ , CaF ₂ , BaF ₂ , LiF, CsF _2, and the like may be used. According to one embodiment of the invention, a representative molten salt is calcium chloride salt (CaCl ₂ ).

For the electrolytic reduction reaction, the molten salt is electrolyzed with a mixture of carbon and titanium dioxide as a cathode.

In the present invention, a mixture of carbon and titanium dioxide may be used, which may be used if carbon is added to titanium oxide. The carbon and titanium dioxide mixture can be represented by C _X Ti _Y O _Z and can be obtained by wet mixing and sintering TiO ₂ with carbon or graphite powder.

For example, a method of preparing the carbon and titanium dioxide mixture is as follows. First, carbon powder is added to titanium oxide. The addition amount is preferably such that the atomic ratio of carbon to titanium oxide is 1: 1 to 1: 2. Examples of the carbon used include carbon, graphite, carbon nanotubes, and the like. Titanium oxide and carbon are mixed well, and the binder and water are kneaded to form various shapes (round pellets, rectangular blocks, cylinders, etc.) and sizes (mm to ㎝).

According to one embodiment of the present invention, the electrolytic reaction is preferably 800 ~ 1300 ℃. Raising the molten salt to the electrolytic reaction temperature removes moisture and can make the molten salt molten.

The electrolytic reaction according to the present invention may use an electrolytic reduction device as shown in FIG. 1, but the present invention is not limited thereto as one preferred example to which the device is applied.

As shown in FIG. 1, the molten salt 2 is accommodated in an alumina or graphite crucible 3 in an electric furnace 1. The carbon and titanium dioxide mixture 4 is used as a sintered body by drilling a hole in the sintered body and connecting it with the Kantal wire 5 to serve as a negative electrode, and the positive electrode connected to the graphite electrode 6. In FIG. 1, reference numeral 7 denotes a thermocouple. After the installation as described above, the potential difference between the two electrodes can be maintained between 2.5 and 3.2V. The electrochemical reaction between the two electrodes can be summarized as follows.

^{_{Anode: C + 2O - = CO 2}} + 4e - , and ^{C + O - = CO + 2e} -

Cathode: TiO ₂ + 4e- = Ti + 3O ^2-

Cathodic Secondary Reaction: Ti + C = TiC

Total: TiO ₂ + 2C = TiC + CO ₂

The carbon-added titanium oxide mixture has abundantly more conductive carbon inside the Ti oxide than the reduction of titanium dioxide alone, which promotes electron movement and forms more channels to improve the flow of electrons. Induction of the electrolysis reaction has the advantage of reducing the Ti to a short time to make a stable TiC compound.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described concretely.

(Example)

TiO ₂ powder (Anatase, Aldrich, purity 99.9 or higher: powder may contain surfactant) and carbon powder were mixed with water to form a slurry. The slurry was slip-cast into various forms (round pellets, rectangular blocks, cylindrical, etc.) and sizes (mm to cm), dried at room temperature, and sintered at 1000 ° C. in an inert atmosphere. The resulting solid has workable strength and porosity of 40-50%.

0.3-10 g of pellets were drilled and connected by Kantal wire and placed in a graphite crucible containing pure CaCl ₂ molten salt (typically 1 kg). Electrolysis was carried out at 950 ° C. for 5-15 hours under 3.1V (between cantal wire and graphite rod electrode) and argon environment.

After washing with acidic leaching (HCl, pH <2) and water, SEM and XRD analysis were performed on the electrolyzed pellets and the results are shown in FIGS. 2 and 3, respectively. As shown in FIG. 2 and FIG. 3, it can be confirmed that TiC powder is generated.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims, and various forms of substitution, modification, and within the scope not departing from the technical spirit of the present invention described in the claims. It will be apparent to those skilled in the art that changes are possible. For example, although CaCl ₂ is used as the molten salt in the embodiment of the present invention, other molten salts may be used.

1 is a schematic view showing an example of an electrolytic reduction reaction apparatus used in the present invention.

2 is a scanning electron microscope (SEM) photograph of titanium carbide obtained by molten salt electrolytic reduction.

3 is an XRD analysis result of titanium carbide.

Claims

Preparing a molten salt of M ₁ X (M ₁ is _one selected from the group consisting of Ca, Ba, Li, and Cs, and X is F or Cl); And

Titanium carbide production method comprising a.

The method of claim 1, wherein the carbon and titanium dioxide mixture is a titanium carbide production method, characterized in that the atomic ratio of carbon to titanium dioxide is 1: 1 to 2.

The method of claim 1, wherein the electrolytic reaction is carried out at a temperature range of 800 ~ 1300 ℃.