Views: 0 Author: Site Editor Publish Time: 2022-10-07 Origin: Site
Zirconium metal products can be divided into two categories. One is nuclear grade zirconium, which is mainly used as the structural materials of nuclear aircraft carriers, nuclear submarines and civil power reactors, as well as the cladding of uranium fuel elements. It is an important strategic metal; The other is industrial grade zirconium (or chemical zirconium, firearms zirconium), which is mainly used to make chemical acid and alkali resistant equipment, military industry, and electronic industry.
Zirconium production process: Zirconium ore is carefully extracted from zirconium ore sand (concentrate), and then smelted into sponge zirconium. Zirconium and hafnium are separated while smelting sponge zirconium to smelt sponge hafnium. Then, sponge zirconium is melted and cast into zirconium ingots (the same as titanium ingots), zirconium ingots are processed into zirconium billets (zirconium tube billets, zirconium slab billets, zirconium rod billets, etc.), and finally zirconium materials are made through extrusion and other pressure processing.
At present, the main production method of metal zirconium is magnesium thermal reduction, that is, the method of preparing sponge zirconium by reducing zirconium tetrachloride (ZrCl4) with metal magnesium. It mainly includes three main links: decomposition of zircon sand and preparation of zirconium tetrachloride; Separation of zirconium and hafnium; Zirconium tetrachloride refining and magnesium thermal reduction to produce sponge zirconium. Nuclear grade sponge zirconium can be produced after three procedures are completed. If general industrial grade sponge zirconium is prepared, it is not necessary to separate hafnium, and industrial grade sponge zirconium can be obtained after completing steps 1 and 3. The sponge zirconium obtained by reducing ZrC14 with magnesium has no plasticity and cannot be directly processed. In addition, zirconium can react with oxygen in the air when heated. Therefore, the sponge zirconium must be melted into ingots after adding a small amount of tin, iron, niobium and other elements according to the characteristics of the nuclear reactor. In the process of smelting sponge zirconium, the extraction and separation of zirconium and hafnium to produce atomic level sponge zirconium is the core technology of its production. If zirconium and hafnium cannot be separated, only industrial grade sponge zirconium (containing about 4-5% hafnium) can be manufactured.
The sponge zirconium standards widely used in the world are mainly American ASTM standards: ASTM B 349 (for atomic energy industry) and ASTM B 494 (for general industry). ASTM B 349 contains one grade R60001, and ASTM B 494 contains two grades R60702 and R60703. The standard of sponge zirconium in China is divided into atomic energy level and industrial level. The atomic energy level includes HZr-01 and HZr-02, among which HZr-01 is basically the same as R60001 in the United States; Industrial grade includes two standards: HZr-1 and HZr-2. HZr-2 is basically the same as R60702 in the United States.
This category is empty.