_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

~. ~ ~ • •
5.5 FIIME 3CRIIBHER AND 3TACR (04-SR-O1)
The scrubber consists of a packed tower followed by a mist
eliminator. A pump (04-PP-22) circulates sodium hydroxide
solution through the scrubber. Make-up NaOH is added in
response to changes in pH as measured by a probe in the
solution recirculation line. Liquid level is maintained in
the reservoir by the addition of process water via valve
HV437 which operates in response to the signal from level
probe LIT440, located in a stilling well.
Air is drawn through the scrubber by a fan (04-FA-O1) and
exhausted to atmosphere via a 30-ft high stack.
5.6 SODIIIM HYDROXIDE STORAGE TANK (06-TR-16)
A 50$ NaOH solution is metered into the scrubber from the
storage tank, which also supplies NaOH to the strip circuit,
'~ via a separate pump and line. The 5,000-gallon tank is
insulated and equipped with a thermostatically-controlled
electric heater to maintain the solution temperature at 75
-95°F and prevent freezing.
~ 5.7 BODIOM HYDROXIDE METERING PIIMPS
,~ (06-PP-37 and 06-PP-38)
•~ Two pumps are installed, one of which is a standby. The
duty pump meters NaOH solution from the storage tank to the
' Fume Scrubber in response to the signal from the pH probe.
[~ The duty pump is manually selected by opening or closing the
~1 appropriate suction and delivery valves.
The duty pump is started when the pH of the recirculating
~'~ scrubber solution falls to 10.5 and stops when the pH has
risen to 11.5. The diaphragm-type .pumps can. ]pe adjusted
locally to regulate the output. During commissioning, the
~~ outputs will be- set so that the duty pump runs almost
continuously, to minimize cycling.
5.8 3IILFIIRIC ACID STORAGE TANK (06-TR-15)
`~ Sulfuric acid (93$) is stored in a 10,000-gallon tank
constructed of high density polyethylene, fiber reinforced
plastic.
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