Document ID: EPA-HQ-OAR-2002-0051-2050
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2009-05-06T04:00Z

Hector.Ybanez@holcim.com 
03/02/2009 03:00 PM	To
	Barnett.Keith@epamail.epa.gov
	cc
	Joel.Bolduc@holcim.com, marvin@rti.org, meg.garakani@holcim.com, "Michael 
Laney" <mnl@rti.org>, ngarnett@txi.com, Thorneloe.Susan@epamail.epa.gov, 
tmatz@htcnam.com, giri.bhavani@holcim.com
	bcc
	
	Subject
	Re: Wet scrubber water treatment
	
	
	History:	
		This message has been replied to and forwarded.

Keith

You are correct; gypsum is recovered from the scrubber by sending the
material to a dewatering facility where the gypsum is dewatered and stored
until it is consumed in the finish mill.  This is a continuous process.
The water is returned back to the wet scrubber.

Additionally, the scrubber is equipped with a storage reservoir.  This is a
non-continuous process; however, when the need arises to bled-down the
reservoir water is consumed by either of the two following methods: (i)
Water from the reservoir is routed to a storage tank where it is stored
till it is consumed as process water.  This is the case for Portland.  (ii)
At Midlothian, the water from the reservoir is routed to a clay-lined pond
where it is stored until it is consumed as process water.  There is no
discharge from this clay-lined pond.

If you have nay questions please let me know.

_____________________

Hector Ybanez
Corporate Manager, Environmental
122 West Carpenter Freeway
Suite 485
Irving, Texas 75039
Phone (214) 524 - 2814
Cell (972) 268-1139
Hector.Ybanez@holcim.com
hybanez@gmail.com
www.holcim.com/us
This e-mail is confidential and intended only for the use of the above
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                   Barnett.Kei                                             
                   th@epamail.                                             
                   epa.gov                                              To 
                                       meg.garakani@holcim.com,            
                   03/02/2009          Joel.Bolduc@holcim.com,             
                   11:52 AM            HECTOR.YBANEZ@holcim.com,           
                                       tmatz@htcnam.com, ngarnett@txi.com  
                                                                        cc 
                                       Thorneloe.Susan@epamail.epa.gov,    
                                       "Michael Laney" <mnl@rti.org>,      
                                       marvin@rti.org                      
                                                                   Subject 
                                       Wet scrubber water treatment        
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           

To All:

A question has come up about treatment of water from kilns that use wet
scrubbers for SO2 control.  In our analysis we assume that the scrubber
blow-down is sent to a dewatering facility where the gypsum is dewatered
and stored prior to being sent to the finish mill.  The water from the
dewatering step is assumed to be sent back to the wet scrubber.

Is there some type of water treatment process that takes place after the
solids are removed from the scrubber blowdown? Or is the water simply
sent directly back to the scrubber?  Is there any liquid waste stream
that leaves the scrubber process?  If so, how is this stream treated and
where does it go?

Keith W. Barnett
USEPA/OAQPS/SPPD/MMG
Mail Code D243-02
Research Triangle Park, NC  27711
919-541-5605
barnett.keith@epa.gov