A Brief Discussion on the Preparation Methods of Industrial-Grade Zirconium Sponge

Industrial Grade Zirconium Sponge is a silver-gray metal that resembles steel in appearance and has a metallic sheen, used in aerospace, defense industries, nuclear applications, and more.

Industrial-grade zirconium sponge has a melting point of 1,852°C, an auxiliary boiling point of 4,377°C, and a density of 6.49 g/cm³. Zirconium readily absorbs hydrogen, nitrogen, and oxygen. It exhibits a strong affinity for oxygen—up to 1,000 times its volume can dissolve in zirconium under certain conditions, significantly expanding its size. However, zirconium is relatively stable in air. On the other hand, powdered zirconium burns easily; fine zirconium particles can even be ignited with a match. At high temperatures, it directly reacts with dissolved oxygen, nitrogen, and hydrogen gas.

The classification of zirconium smelting products is based on the needs of various industrial applications, including Industrial Grade Zirconium Sponge, fire-resistant zirconium, nuclear-grade Industrial Grade Zirconium Sponge, and zirconium powder. Since the raw materials and final products differ, the smelting processes employed also vary accordingly.

1. Industrial-grade zirconium sponge production process: Using industrial-grade zirconia as the raw material, ZrCl₄ is obtained via chlorination and subsequently reduced with metallic magnesium. The resulting product is then purified and further processed through vacuum distillation to yield industrial-grade zirconium sponge. Alternatively, zircon sand can be directly chlorinated to produce crude ZrCl₄, which is then refined before undergoing magnesium-based reduction and final vacuum distillation to produce industrial-grade zirconium sponge.

2. Industrial-Grade Zirconium Sponge Production Process. Nuclear-grade Industrial-Grade Zirconium Sponge must undergo hafnium separation; however, the overall production process is similar to that of industrial-grade zirconium sponge. The industrial-scale methods for separating zirconium from hafnium include: an extraction-based method using oxygen chlorides as feedstock, a gas-phase separation technique employing zirconium tetrachloride, and a stepwise crystallization method utilizing potassium bromate as the raw material.

3. Electrolytic zirconium production process: The metal powder produced via the potassium bromate molten-salt electrolysis method is subsequently processed into finished products through die-casting and subsequent melting.

4. Thermal Reduction and Hydrogenation of Zirconium Powder: The thermal reduction method uses zirconium oxide as the raw material and calcium (calcium hydride) as the reducing agent to produce zirconium powder. The hydrogenation method involves reacting the raw material at temperatures between 400°C and 800°C to form zirconium hydride. After crushing and ball milling, the material is heated further at 800–1000°C to remove hydrogen, yielding the final powdered product.

Industrial-grade zirconium sponge is used in a wide range of applications, including aerospace, defense industries, nuclear reactors, atomic energy, the addition of ultra-hard metal materials, the production of alloy steels, and uranium fuel-coated alloys for use in reactors. Zirconium readily releases electrons at high temperatures. Key product features include exceptional corrosion resistance, as well as ultra-high hardness and strength.

The preparation method for Industrial-Grade Zirconium Sponge involves the following steps: (1) Heat a mixture of Zirconium Tetrachloride and Hafnium Tetrachloride at temperatures exceeding 331°C to produce a gaseous mixture. (2) After heating, introduce the resulting gas mixture into a protective gas environment and condense the Zirconium Tetrachloride within it under constant temperature conditions maintained between 317°C and 330°C. Subsequently, separate the solid Zirconium Tetrachloride from the remaining gaseous mixture. (3) Refine the collected solid Zirconium Tetrachloride at least once to obtain Zirconium Tetrachloride of atomic-grade purity, along with concentrated Hafnium Tetrachloride in trace amounts. (4) Reduce the high-purity Zirconium Tetrachloride to yield Atomic-Grade Industrial-Grade Zirconium Sponge. This invention’s method for producing Atomic-Grade Industrial-Grade Zirconium Sponge boasts several advantages: a streamlined process, efficient separation using non-toxic reagents, environmental friendliness, and significantly reduced production costs.