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July 25, 2017 Liners

Grinding balls are usually regard as the commodity within mineral processing plants. According to production technology, they are generally divided into cast and forged balls. Let’s make a further understanding of forged grinding balls and the product performances of Shandong Iraeta. 


The raw material of forged grinding media are usually as follows: 45# steel, 60Mn, 65Mn, 40Cr, 42 CrMo, B2, B3, B6, etc. grinding media can be manufactured by hot rolling and forging with air hammer when the carbon content is 0.4-0.85, manganese content 0.5-1.2, chromium content 0.05-1.2. Such kind of grinding media are mainly used for mining separation as well as electricity plant. In Shandong Iraeta, the grinding balls with 25-125 mm in diameter are manufactured by automatic hot rolling production lines controlled by computer, while diameters within the range of 125-150 mm are forged by air hammer.

The production process of air hammer forged grinding media is as follows:
1. Inspect raw material. Shandong Iraeta only purchase steel bars from standard steel enterprises. Besides, we have rigorous supplier evaluation system and the purchasing specialists with over 10 years of experience.
2. Feed the qualified steel bars according to grinding media demand size. To get the good deformation, steel blank will be heated in intermediate frequency electric furnace to a certain temperature.
3. The heated steel blank will be transmitted to air hammer and forged repeatedly by skilled workers.
4. Shift the hyperthermal grinding media to the continuous tempering furnace to do quenching and tempering heat treatment. With the specially designed heat treatment equipment, our grinding media will obtain a uniform and relatively high hardness value. 


Currently, forged grinding balls are widely used by the international mining giants in wet grinding, including Rio Tito, BHP Billiton, CVRD, South Africa Gold, Codelco. In China market, cast ball is in the majority while the demand quantity of forged ball is increasing gradually. China Minmetals, Zijin Mining, China Gold, and TISCO are also using forged balls. In recent years, because of the high broken rate of high chrome steel balls in semi-self-grinding machine, forged ball becomes the only choice.

With the prevalence of forged grinding media, its advantages are quite obvious, smooth surface, high impact toughness as well as low breakage. Actually, with competitive price and high abrasion resistant performance, the cost effectiveness of forged steel ball is much better than high chrome balls. 

Grinding media specifications in Shandong Iraeta are as follows.
1.Breakage: less than 0.5%
2. Impact toughness: over 18J/cm2.
3. Surface hardness: 58-65HRC; volume hardness: 56-63HRC.
4. No deformation: without losing round and never deformation.


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