Classification of ball mills according to industrial and mining conditions

    There are many different kinds of steel balls for ball mill, such as forged steel balls and cast steel balls, among which forged steel balls are abbreviated as forged balls; cast steel balls are abbreviated as cast balls, and cast balls are divided into high, middle and low chromium. We have very limited knowledge of ball mill steel balls. Today, we mainly talk about the quality indicators of these different ball mills, hoping to bring help to you.

I. Quality Index of Forging Ball

Forging balls are made of round steel by different processes. The carbon content is less than 1.0%. The quality of materials is very important to the quality of products (alloy elements). There is no gate on the surface. The balls will not deform during grinding. They are always spherical. The current production processes include air hammer forging and rotary cutting rolling sections.

II. Quality Indicators of High Chromium Balls

High chromium spheres with chromium content (>10.0%) and carbon content (>1.80%-3.20%) are called high chromium spheres. The national standard requires that the hardness of high chromium spheres (HRC) must be (>58) and the impact value AK (>3.0J/2). If the hardness of high chromium spheres is reached, they must be quenched by high temperature and tempering (at present, there are two quenching methods of oil quenching and air quenching in domestic high chromium spheres). If the hardness (HRC) is lower than 54, it means that Fire treatment.

III. Quality Indicators of Medium Chromium Balls

The chromium content ranges from 3.0% to 7.0% and the carbon content ranges from 1.80% to 3.20% are called medium chromium spheres. The impact value AK is more than 2.0J/2. The hardness of chromium spheres (HRC) required by national standards must be more than 47. In order to ensure the quality of chromium spheres, high temperature tempering treatment (in order to eliminate casting stress) should be adopted. If the surface of steel spheres is dark red, the products have been tempered at high temperature, such as the surface of steel spheres is still gold. Natural color indicates that the product has not been tempered at high temperature.

IV. Quality Indicators of Low Chromium Balls

Low chromium spheres with chromium content of 0.5%-2.5% and carbon content of 1.80%-3.20% are called low chromium spheres. The national standard requires that the hardness of low chromium spheres (HRC) must be more than 45 and the impact value AK should be more than 1.5J/2. In order to ensure the quality of low chromium spheres, high temperature tempering treatment (in order to eliminate casting stress) is also needed. If the surface of steel spheres is dark red, the product has been tempered at high temperature, such as the surface of steel spheres is still gold. Natural color indicates that the product has not been tempered at high temperature.

Forged balls are made of high-quality steel, while cast balls are scrap iron. Forged balls are not easy to deform in use because of their better surface quality than cast balls. Cast balls are only suitable for dry grinding, while forged balls are inherently corrosion-resistant due to the use of high-quality steel casting. Both dry and wet grinding are applicable.

Generally speaking, cast balls can be called heat-resistant balls, suitable for dry grinding, suitable for cement mills, suitable for forging balls can be called corrosion-resistant balls, suitable for wet grinding, mineral processing and other forging balls, especially for semi-autogenous mills or balls over 100mm.