Dry grinding process for reducing ore to pelletizable particles
AssigneeMetallgesellschaft Aktiengesellschaft
InventorsFriedrich Rosenstock, Walter Hastik, Reinhold Becker
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Abstract
A dry grinding process for reducing ore to pelletizable particles comprises grinding the ore in a size-reducing unit and classfiying the ore in a centrifugal pneumatic separator which is automatically controlled to make the coarse fraction available at a substantially constant rate. The coarse fraction is recycled to the size-reducing unit and the total rate of fed ore and recycled coarse fraction is maintained substantially constant. The ore-feeding rate is varied when, and only when, a controlled variable of the pneumatic separator has a deviation in excess of a predetermined permissible deviation.
Claims4
A process for dry grinding ore to produce pelletizable particles which comprises the steps of:
- a. grinding ore in a size-reducing unit;
- b. classifying the ground ore in a centrifugal pneumatic separator into a coarse fraction and a fine fraction, said centrifugal pneumatic separator having a controllable operating parameter;
- c. recycling the coarse fraction into the size-reducing unit;
- d. discharging the fine fraction as a finished product;
- and
- e. maintaining a substantially constant total rate of ore feed and recycled coarse fraction feed to said size-reducing unit by
- maintaining the ratio of the ore-feed rate to the coarse fraction recycled rate substantially constant,
- automatically controlling the centrifugal pneumatic separator to make said coarse fraction available with a varying particle size fraction at a substantially constant rate, and
- varying the ore-feed rate when and only when, said controllable variable of the pneumatic separator has a deviation in excess of a predetermined permissible deviation.
Dependencies are inferred from the claim text.