_REVISION - M1988112 ‎(2)‎

• Permit No: M1988112
• IBM Index Class Name: Revision
• Doc Name: TAILINGS PH ADJUSTMENT SYSTEM OPERATIONS REVIEW
• Type & Sequence: TR5
• Media Type: D
• Archive: No

~'
.l
7.1 EQIIIPMENT FAILURE
SECTION 7.0
FAILIIRE ANALY328

The following paragraphs describe the consequences of
failure of each of the equipment items in the p~FI Adjustment
System.
pH Adjustment Tank Agitator (04-AG-09)
J Mechanical or electrical failure of the agitator will result
in a reduction in the level of mixing within the tank. A
fault stop of this drive does not cause any other drive to
stop. The slurry in the tank is agitated by the large
volume of air provided by blower 04-CP-03 via the four
1 sparge pipes. Operation of the system can cohtinue until
it is convenient to shut it down for repair. Failure of the
agitator does not present a hazard.
Carbon safety Screen (04-SC-10)
Failure of the Carbon Safety Screen necessitates stoppage
of feed to the plant. The pH Adjustment System is shut down
in sequence in the normal way. The agitator continues to
run to maintain suspension of the solids. The situation
does not constitute a hazard. However, precautions must be
1 taken to prevent exposure of personnel to iesidual HCN
J during repair of the screen. Refer to Section 8.0 for
details.
J pH Adjustment Hlover (04-CP-03)
Failure of the blower stops the flow of air into the slurry
in the pH Adjustment Tank. The Sulfuric Acid Metering Pump
stops, the pH increases and HCN stripping ceases. The Fume
Scrubber continues to run to absorb any Residual HCN _
evolved. The agitator continues to run to maintain y, •5}0~
suspension of the solids. The situation does nat constitute or,c~
a hazard. However, continued operation will result in ~;.~`
discharge to the tailings impoundment of slurry containing
higher than normal levels of cyanide.
1

1 pj/1504rp 012591 7-1