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Title: Process for cleaning undeslimed coal

Patent ·
OSTI ID:5649116

A process for cleaning undeslimed coal includes the steps of determining the scalar value of cross-correlation function of the measured values of the percent magnetics and the bulk specific gravity of a heavy media and coal slurry being fed to a cyclone, comparing the value to a set-point value determined after start-up when the recirculating suspension in the feed slurry is normally clean, and diverting at least a portion of the heavy media suspension that is separated from the underflow of the cyclone from being mixed with the feed coal slurry, to thereby correspondingly recycle the slime content of the feed slurry, and concurrently increasing the flow of cleaner heavy media suspension to the feed coal slurry until the cross-correlation function is brought up to the set-point value. Also disclosed is an embodiment of the process for cleaning coal, wherein the overflow from the cyclone is screened and screened solution is split between a first recycle loop for cleaning the suspension and the heavy media sump. Similarly, the underflow from the cyclone is screened and then split between a separate recycle loop and the heavy media sump. Suspension is diverted to the heavy media sump from one or both recycle cleaning loops as necessary. The remaining portions of the split suspension flows from the two screening devices are, in turn, respectively split between two further sumps and the heavy media sump, with more suspension coming from the cyclone overflow screen when cleaner suspension is indicated as being necessary by the aforesaid statistical analysis.

Assignee:
Envirotech Corp.
Patent Number(s):
US 4405453
OSTI ID:
5649116
Resource Relation:
Patent File Date: Filed date 23 Feb 1982; Other Information: PAT-APPL-351384
Country of Publication:
United States
Language:
English