UMS Unidan Ball Mill

Wear-resistant and easy to maintain, the FLSmidth ball mill is the clinker grinder that just keeps rolling

  • The basics
  • Design
  • Maintenance

Key benefits

  • Highly reliable
  • Easy operation, easy maintenance
  • Wear-resistant parts – durable shell lining
  • Open or closed circuit operation
  • Grinds to any level of fineness
  • Energy efficient; large through-flow area ensures low pressure drop
  • Adapts to capacity, plant layout and end product

How it works

The FLSmidth ball mill grinds cement clinker, gypsum and similar materials of moderate moisture content in a one-compartment or two-compartment system. As the crushing compartments rotate, the balls inside them grind the clinker. Ball size determines the degree of product fineness.

The FLSmidth ball mill can operate in an open or closed circuit and has a corrugated lining in the grinding compartment for added effectiveness.

The ball mill consists of standard modules that can be configured for capacity, plant layout and end-product specifications. The drive can be fitted as a side or central drive upon request, and mills can be fitted with pre-grinders to achieve maximum grinding efficiency for any specified end-product quality. When fitted with the Hydraulic Roller Press (HRP) as a pre-grinder, for example, the power consumption of the whole mill system can be reduced by up to 30%.

The FLSmidth ball mill is easy to operate and maintain, ensuring production efficiency and high mill run time. A large through-flow area facilitates the flow of venting air, which in turn ensures a low pressure drop across the mill and thus lower energy consumption.

STANEX diaphragm

The STANEX diaphragm is situated between the grinding chambers of the two-compartment FLSmidth ball mill. It effectively screens the material for size as it passes from the coarse to the fine grinding compartments. The diaphragm is fitted with adjustable lifters to ensure an adequate level of material in the coarse grinding compartment. It has segmented, bolted, wear-resistant grates, and its structural parts are made of mild steel.

Efficient cooling and drying

An internal water-cooling system can be installed in the grinding compartments to optimise mill performance and control the material temperature inside the mill and at the mill discharge point.

For grinding of materials with a higher moisture content, drying compartments with lifters can be added to the system.

Mill linings

The linings inside the mill compartments are very durable and can last up to five years with proper care.

The shell lining of the first compartment in the two-compartment FLSmidth ball mill is a highly wear-resistant step lining specifically designed for the coarse grinding chamber. A rubber backing prevents damage to the mill shell and lowers the noise emission from the mill during operation.

For the second compartment, and for the single compartment mill, the lining is corrugated for maximum power absorption and grinding efficiency.

For fine grinding requirements, a classifying lining is employed.

Durable wear parts

Wear parts that are exposed to high stress are protected by bolted-on, wear-resistant lining plates. Mill linings are very durable and can last for up to five years with proper maintenance.

The most critical zones on a FLSmidth ball mill shell in regard to cracks are the areas around bolt and man holes, due to high stress levels in those areas.

Preventive maintenance

The FLSmidth ball mill requires little service, and a few simple maintenance procedures will keep it going strong for extended periods.

Preventive maintenance of ball mills should always be condition based. This allows for planned production stoppage for maintenance. The main focus should be on systematic observation and inspection of the mill body, bearings and mill drive, both when the mill is running and stopped.

It is important always to keep the surrounding area free of debris.
Mill maintenance
Mill maintenance