The quality of zirconium concentrate varies with resources, and there is no international standard. Therefore, the companies or manufacturers of each producing country have their own standards according to their resource characteristics and user requirements. The national standards for zirconium concentrate in China are shown in the table below. Table National Standard for Zircon Concentrates in China level chemical composition,% Particle size mm (Zr, Hf)O 2 Impurity content TiO 2 P 2 O 5 Fe 2 O 3 Al 2 O 3 SiO 2 Premium product 65.50 0.3 0.20 0.10 0.3 34 -0.4 First grade 65.00 0.5 0.25 0.25 0.8 34 -0.4 Second grade product 65.00 1.0 0.35 0.30 0.8 34 -0.4 Third grade 63.00 2.5 1.50 0.50 1.0 33 -0.4 Fourth grade 60.00 3.5 0.80 0.80 1.2 32 -0.4 Five grade 55.00 8.0 1.50 1.50 1.5 31 -0.4 Timing Cover,Front Timing Cover,Timing Chain Cover,Timing Belt Cover Ningbo Maixun International Trade Co., Ltd , https://www.nbmachinery.com