Methods of making titanium diboride powders

#In the production of aluminum and other metals, materials that withstand extreme conditions (i.e. high temperatures and/or corrosive environments) are used for various electrolysis cell components. An example of one such material is titanium diboride.

#Titanium diboride (TiB2) has unique mechanical, physical, and chemical properties which make it a desirable material for various applications, including for example, electrolysis cell components. The particle size of the titanium diboride affects processing parameters, including: sinterability and formability into TiB2-based products, and thus, the titanium diboride particle size affects the performance of TiB2 products.

#Broadly, the present invention is directed to synthesizing titanium diboride with a specific particle size (e.g. average particle size). The present inventor has discovered that by controlling one or more processing variables; the resulting particle size of the titanium diboride product is also controlled. Thus, the particle size of the titanium diboride product may be directed by varying the amount of sulfur in the chemical reaction of titanium diboride (e.g. carbothermic reaction); by varying the soak time of the precursor mixture; by varying the reaction temperature, and/or by varying the flow rate of an inert gas through the reactor. One of more of these factors may be varied individually, or in combination, in order to effectively produce a titanium diboride product having a specified average particle size (or average particle diameter when a spherical/circular particle). Other parameters, including purity and/or surface area may also be controlled with one or more of these variables. Thus, the titanium diboride made in accordance with the present disclosure may be used in various applications which may require different average particle sizes and/or purity of the titanium diboride. In some embodiments, the titanium diboride products of the present disclosure may be used in electrolysis cell components and/or electrodes, including, for example, cathodes.

#FIG. 1 is a flow chart depicting an embodiment of a method of the present disclosure.

#FIG. 2 is an embodiment of a process flow chart for the chemical production of titanium diboride.

#FIG. 3 is a diagram of an embodiment of a reactor which can be used in accordance with the embodiments of the instant disclosure.

#Carbothermic Reduction and Related Reactions:

#Carbothermic reduction is a solid state synthesis method to make TiB2, which utilizes a carbon source to reduce boron and titanium oxides at temperatures in excess of 1350° C. (e.g. 1375° C. In some embodiments, titanium diboride particles may be prepared by carbothermal reduction of titanium dioxide, boric oxide and carbon in accordance with Equation (1). TiO2+B2O3+5C→TiB2+5CO  (1)

#In one embodiment, titanium diboride particles can be produced by carbothermal reaction of titanium dioxide, boric acid, and carbon in accordance with Equation (2). TiO2+2H3BO3+5C→TiB2+5CO+3H2O  (2)