Abstract: Taking fine crushing ores from Qidashan iron ore as study object, the grinding characteristics and liberation characteristics of high pressure grinding roller product were investigated and compared with that of the laboratory jaw crushing products. The results showed that: the Bond ball mill work index of HPGR products were respectively lower by 13.96% and 28.23% than that of the jaw crushing product when the particle was in 0.074 mm and 0.280 mm. With regrinding fineness of -0.074 mm 80%, the relative grind-ability of HPGR and JC product in particle size of -3.2 mm and 3.2~0.074 mm reached 0.83 and 0.86. Compared with the JC products, the liberation degree of HPGR product in -0.5 mm was increasing by15.16%, and the liberation degree of iron ore in HPGR product is higher by 5.55 to 0.98 percent point under different grinding fineness. In addition, the intergrowth of valuable minerals in HPGR product can be easily liberated at secondary grinding, while JC product was in reverse.

Key words: High-pressure grinding roller, Grinding characteristics, Liberation characteristics