What are the types of grinding media for Ball Mills
There are many different kinds of grinding media used in ball mills, such as forged grinding media and cast grinding media. Among them, forged grinding media are called forging balls for short; cast grinding media are called casting balls for short; cast grinding media are divided into high, medium, and low chrome. Today, the main ball mill is the quality of these different indicators of grinding media, we hope to bring help.
Quality Index of Forging Ball
The forging ball is made of round steel by different process, the carbon content is below 1.0% , the quality of the material is very important to the quality of the product (Alloy Element) , there is no pouring port on the surface, the ball will not be deformed in the grinding process, and the ball is always spherical At present, there are two kinds of production technology: Air Hammer forging and rotary cutting and rolling.
Quality Index of High Chrome Ball
The National Standard requires that the hardness (HRC) of high chrome ball should be ≥58 and the impact value AK should be ≥3.0 J / 2. If the hardness of high chrome ball is lower than 54 HRC, the high chrome ball has not been quenched.
Quality Index of medium Chrome Ball
The impact value AK ≥2.0 j / 2, the hardness (HRC) of medium chrome ball must ≥47. In order to ensure the quality of grinding media, the chrome balls need to be tempered at high temperature (in order to eliminate the casting stress) , if the grinding media surface dark red indicates that the product has been high-temperature tempering, if the grinding media surface is still metallic color indicates that the product is not high-temperature tempering.
Quality Index of low Chrome Ball
The content of chrome is 0.5%-2.5 %, the carbon content is 1.80%-3.20 %, which is called low chrome ball. The National Standard requires that the hardness (HRC) of low chrome ball must be over 45, the impact value AK ≥1.5 j / 2. In order to ensure the quality of low chrome ball also need to use high temperature tempering (in order to achieve the goal of eliminating casting stress) , if the grinding media surface dark red indicates that the product has been high-temperature tempering, if the grinding media surface is still metallic color indicates that the product is not high-temperature tempering.
The forging ball is made of high-quality steel and the Casting Ball is scrap iron; the forging ball is not easy to be deformed in use because of its better surface quality than the casting ball; the casting ball is only suitable for dry grinding, while the forging ball is naturally corrosion resistant due to the use of high-quality steel in Casting Suitable for both dry and wet grinding.
Generally speaking, the cast ball can be said to be “heat-resistant” ball, suitable for dry grinding, cement plant with the cast ball is more suitable, forging ball can be said to be “corrosion-resistant” ball, suitable for wet grinding, ore dressing, such as forging ball is more suitable, especially semi-automatic mill or 100 mm above the ball.