Grinding steel balls are used in mining, coal, construction (for example, to make cement) and other industries. They are used in ball mills as grinding bodies for grinding materials by impact, abrasion and crushing. The balls are produced from iron and steel which helps in the grinding effect due to their weight and durability.
The most common technology for producing steel grinding balls is hot-rolling. Cross-rolling is used when the initial round billet, after heating in the furnace to a predetermined temperature, is fed to a ball rolling mill, where it is reduced in rolls with screw gauges rotating in the same direction. A schedule of two or three rolls can be used. When leaving the rolling stand, the grinding media are cooled with water or a water-air mixture to increase strength properties, with further self-tempering in the bins.
An alternative method for producing grinding balls is stamping, but it is less common due to lower line productivity (two to three times) and higher metal consumption (10-20% more).
Main Features Of Grinding Steel Balls
The main features and classifiers are:
- Product material: iron, steel, carbide material, ceramics
- Production technology: centrifugal casting, hot-rolling, casting, stamping, sintering
- Ball diameter: mm
- Hardness: normal, higher, high
The main quality parameters of steel grinding balls manufactured according to DSTU 8538 are: rated diameter, nominal diameter, maximum deviations of diameter and hardness. The rated diameter is the diameter of the ball, rounded to the nearest values of the standard series. The nominal diameter is the diameter against which the limit deviations are determined. Maximum deviations are the difference between the limit and nominal diameters.
Sizes & Packaging.
The sizes of steel grinding balls can be designed according to customer requirements. Generally, the diameter of steel balls for sale is between 20mm and 125mm.
1. Small steel balls: 40mm or 60mm.
2. Medium balls: 80mm.
3. Large steel balls: 100mm or 120mm.
4. Super large balls: 130mm to 150mm.
To pack these grinding balls, steel drums are used. These are often shipped and stored in warehouses. Below is an image of a customer’s grinding balls that are being stored at Seamaster Warehouse right here in Durban, South Africa. These drums are stored until the customers want the grinding balls delivered.