A manufacturing method of a carbide includes steps as follows. A carbon source is provided, a contacting step, a heating step and an electrochemical step are performed. The carbon source includes an amorphous carbon and a compound. The compound is a chalcogen compound, a pnictide compound, a halide, a hydroxide or a salt of a metal or a metalloid. In the contacting step, the carbon source is disposed in an alkaline earth metal halide to form a reactant. In the heating step, the reactant is heated to form a heated reactant. In the electrochemical step, a current is applied to the heated reactant, wherein the current passes through the carbon source, so as to make the alkaline earth metal halide, the amorphous carbon and the compound react with one another to form a carbide of the metal or the metalloid.

A heating element is used, a periphery of the heating element is covered with a net-shaped conductor, the conductor and a carbon fiber bundle are electrically connected with a connecting tool at one end of the heating element, a periphery of the conductor is covered with an outer skin having flexibility, thermal conductivity and an insulating property, and the other end of the heating element is provided with a power supply terminal configured to supply power.

A heating element is used, a periphery of the heating element is covered with a net-shaped conductor, the conductor and a carbon fiber bundle are electrically connected with a connecting tool at one end of the heating element, a periphery of the conductor is covered with an outer skin having flexibility, thermal conductivity and an insulating property, and the other end of the heating element is provided with a power supply terminal configured to supply power.

In a process for manufacturing foamed material an expansion agent, a ceramic base material and water are blended together. The blend is heated and pressurized to homogenize and liquefy or plasticize it. The blend is then extruded through a die where, in the course of the extrusion, superheated water in the blend vaporizes to foam the blend. To make articles of manufacture, extrudate is cut to length, machined and fired, or is injection molded while still malleable and then fired.

Methods of making sintered ceramic particles include preparing an aqueous slurry containing an alumina-containing raw material and a binder containing a raw plant material, forming the slurry into green pellets, and sintering the green pellets to provide the sintered ceramic particles.

An extrusion method and apparatus are described for producing ceramics, glass, glass-ceramics, or composites suitable for use as proppants. The method includes forming one or more green body materials, extruding the green body materials to form a green body extrudate, separating and shaping the green body extrudate into individual green bodies, and sintering the green bodies to form proppants. The apparatus includes a means for forming an intimate mixture of green body materials, means to produce a green body extrudate, means for separating and shaping the green body extrudate into individual green bodies, and means to sinter the green green bodies to form proppants.