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Safe operation of batch ball mills used in potteries and allied industries

OC 690/13v2

Safe operation of batch ball mills used in potteries and allied industries

This OC draws attention to the attached information document (ID) which deals with safety aspects of the design, operation and maintenance of batch ball mills used in pottery and allied industries. The ID should be made available to potteries with ball mills and may be copied to other interested parties outside HSE.


1 Sealed Batch ball mills (BBMs) are closed containers used for fine grinding of the raw materials used in the production of ceramic products. The mill is filled with the material, grinding media and water and operates continuously for periods typically between 2 and 40 hours. Whilst this type of mill is also used in other industries, particularly paint making, the advice in the ID has been produced only with the conditions in the ceramics and allied industries in mind.

2 This revision of the ID has come about because of further incidents of over pressurisation resulting in explosions. It takes into account advances in monitoring methods and the findings of research work commissioned by the British Ceramics Confederation, carried out by SIRIUS (Structural Integrity Research Institute University of Sheffield).

3 The ID has been produced in conjunction with users, manufacturers and other interested parties. It deals in particular with the:

1) safe working practices;

2) periodic inspection of BBMs as required by the Provision and Use of Work Equipment Regulations 1998 reg.6;

3) methods of monitoring the conditions within the BBM;

4) steps which can be taken to detect errors in charging before they present dangerous conditions.

Action by inspectors

4 When discussing BBMs, inspectors should alert users to this new guidance.

Cancellation of instructions

5 OC 690/13 (January 1995 version) - cancel and destroy .

Date first issued: 17 January 1995

Updated 2012-03-21