THE CELLULOSE GRINDING

We continue to introduce our readers to interesting queries that come to us for miscalculation of grinding balls assortment.

The first request, in 2022, came from Belgium. The company is a cellulose grinding company. Cellulose shredding is the first and so far only case where the conversion of natural cellulose into hydrate cellulose is done without chemical action on cellulose. Cellulose can be grinded in different types of ball mills, namely tubular, planetary or vibration mill.

In our case, a ball mill of 2500x3000mm is used for grinding; the main electric motor has a power of 160kW. The armor in the mill is made of rubber, wavy-shaped plates with small elevators. The load of the mill is 20t. The grinding media is a 50 mm diameter steel balls. This grinding process is characterised by two factors:

• Flammability of the ground medium in the ball mill;
• The periodic type of grinding. One grinding cycle lasts 8 hours.

We want to note that our specialists first encountered such a production. We studied cellulose grinding in ball mills. The most important factor in the choice of grinding balls (for these conditions) is the complete absence of a possible split of balls during operation. A split (under normal operating conditions) may result from an excess of internal tension within the ball. At the moment of splitting (release of internal energy), a very high probability of occurrence of «spark», which can lead to burning of ground material. Based on the information collected, our specialists were able to offer the quality of grinding balls (chemical composition and hardness), which would be the optimal for grinding material in given specific conditions. At present, our offer currently under consideration by technical specialists of the client.