Pulp and Paper Technical Association of Canada/TAPPI Bleaching Committee Joint Meeting

• Harmac - same as AlPac
  
• Elk Falls, Mackenzie, Kamloops - Epo into suction of MC pump
  
• Liebergott - no difference between Epo and Eop if within 2 seconds, if added too early will oxidize the filtrate
  
• Grand Prairie - Eop - reduced 12 lbs/t to 8 lbs/t, found no difference in pulp, but effluent colour increased
  
• Howe Sound, Marathon - just above suction of pump
  

• no

• Mackenzie - add 93% to minor dilution, control to 3.5 before lO2 addition
  
• Harmac - add 93% to static mixer just before static mixer, control to 2.5 pH before ClO2 addition, see huge savings in ClO2
  
• Liebergott - if you go too low in pH (best 2.5 to3 pH) will make chlorate
  
• Howe Sound - pH control on minor dilution which is controlled by pH controller on stock line
  
• Kamloops - acid to filtrate from brown decker and control to 6.2-6.3 to get 2.5 in Do stage washer, in chip mill add into pulp before HiD to 6 pH then after HiD, saw no redeposition in HiD
  
• PG Pulp - 40 min retention in HiD, savings of $1.50/t
  
• Histed - redeposition could be due to poor washing if lots of lignin present - precipitates at pH 7
  

• Irving P&P - CO2 to press conveyors dilution to improve bs washing, see decrease in conductivity on second post oxygen washer
  
• Crofton - 25% savings in COD and soda losses, even larger drop in unwashed k number, no corrosion problems noted, should not drop below 8 pH due to lignin precipitation
  
• Elk Falls - to wash water for chemiwasher, some reduction in COD and soda
  
• Western - CO2 to shower bar on bp pre washer, get reduction in COD, soda, higher consistency off washer
  
• Marathon - BL filters may get eaten out due to low pH
  

• Celgar - Ahlmix and Kamyr - both did a good job
  
• Crofton - Kamyr changed out to Ahlmix, but too large, so changed back to Kamyr
  

• Northwood - post Eop, on control, 3-5 k number
  
• Stone Consolidated - post Eop - 2.8 kappa
  
• Irving - Eop to vat - 2.4-2.6 k number
  
• Canton - CEK - target 2.0 on control
  
• P&T Halsey - CEK - 2-3 K number
  

• Celgar - oxygen -2 gpl sulphide, run oxidation at 10-15 gpl
  
• Howe Sound - oxygen - haven't used their system either so use caustic
  
• AlPac - oxygen system - also had problems, so put recirculation line in to keep efficiency up, but have serious scaling problems, found that unit was initially oversized, have a lot of calcium in system
  
• Union Camp - oxygen - use oxidized WL in extraction and oxygen systems, modify to put extra retention time to get efficiency up, but have a problem with "muddy" wl
  
• Cariboo - air - use BL as catalyst, runs efficiently unless running to high a rate
  
• Espanola - air -BL as catalyst, get 88-90% efficiency
  

• Marathon - .03-.04 gpl ClO2 residual, so don't need it
  
• ElkFalls - .07 gpl , don't use it
  
• Harmac - use SO2, considered sodium bisulphide, decided to stay with SO2
  
• Buckeye - SO2, nitrogen padding eliminated a lot of problems - well maintained system is no problem
  
• Howe Sound - SO2 required for TCF to eliminate peroxide residuals
  
• Westvaco - papermakers add SO2 when pulp mill tells them about high residuals
  
• Histed - if sodium sulphite will lose brightness, caustic will lose even more
  
• Liebergott - two mills use peroxide to kill ClO2
  
• Halsey - bisulphite to white water on pulp machine
  
• Harmac - peroxide is too expensive as a replacement for SO2
  

• Hinton - yes
  
• Grande Prairie - used sesqui in bs to control pH until it corroded all mild steel, now use in green liquor
  

• Liebergott - pH shock from 3.5 pH to 9.5 pH - need to stop and clean out once in awhile
  
• Kamloops - found lots of pluggage on wire and ring dilution line to tower, cleaned on the run by switching from caustic to SO2 on that line. Now don't use caustic.
  
• AlPac - startup with DND at 7-8 pH, when changed to 9-10 pH found plugging of ring dilution line so went back to lower pH. Since then have gone to open three stage wash.
  
• HASimons - above pH 9 calcium scale is insoluble
  

• Harmac - same problem, but did not find on-line device
  
• AlPac - at startup had this problem, now have frequent PMs
  
• Mackenzie - PM every month check screens
  
• Northwood - testing does not pick up big stuff - there is an on-line device, but very expensive
  
• Buckeye - do decker shive counts every hour, but probably not very useful, PM outage every eight weeks
  
• Champion - no good test, PM on baskets is probably the only way, where possible go from slots to holes
  
• Espanola - operator can make handsheets of every screen
  
• Northwood - can't see on individual screens
  
• Crofton - go through 4 to 5 sets of baskets per year, do Pulmac tests whenever a problem is identified
  
• Champion - run stock over light box continuously - Crofton and Northwood had these, but eliminated them
  
• P&T - installing Krebs cleaners ahead of screens
  

• sell into LWC market - Mackenzie, Elk, Crofton, Howe Sound, Harmac, Northwood, Kamloops, Cariboo, Grande Prairie, Alpac
  
• 5 mills use Paprispec full time, 1 only runs on demand
  
• background levels of plastic range from 1 to 20 specks per bale, concerns at 5, 10 specks per bale
  
• Marathon - 1.8 specks/100kg = 5 / bale
  

• CEK number - 5 mills
  
• Eo brightness - 9 mills
  
• kappa factor - 2 mills
  
• Do brightness - 3 mills (must have residual or will get reversion)
  

• Buckeye - platform all around car
  
• Elk Falls - if short term exposure, then there is a clause in the regulation allowing a variance
  
• Celgar - hand rails swing down
  

• Kamloops - vent to solution tank
  
• Harmac - vent to Eop filtrate tank
  
• Northwood - vent to Turbotac
  
• Cariboo - vent to Turbotac
  

• Howe Sound - all towers have flow control
  
• Elk Falls - level control, then vat dilution downstream of stock flow, cameras so operators can see thickness. Broke D2 tower J tube, so now have pressure control loop on gooseneck
  
• Champion - stock flow control
  
• Harmac - stock flow control
  
• Buckeye - stock flow control
  

• metal buckets
  

• Crofton - .15/3.6
  
• Marathon - .18 / 2.8-3.1 in
  
• Howe Sound - .22/2.2 going in
  
• Buckeye - .3/2.4 going in
  
• Harmac - in 2.5, out 2.0/.15, .17,.22
  
• Elk Falls - .3/.25 for both lines 2.5
  
• Northwood - pH 3-3.5, .13 low consistency, .18 MC
  
• Stone - 3.5 / .24
  
• AlPac .22-.28/3-3.5in, 2.8-3 vat
  
• Kamloops - vat 2.5/.2
  
• Champion - .22/vat 2.5
  
• Sterling - Doug Prycke's survey has all mills in Canada
  
• Grande Prairie - .22/vat 2
  
• Mackenzie - .28/3.5 in
  
• Cariboo - .19/2.2 in
  

• no
  

• Potlatch, Arkansas has a bunch
  

• Irving - finished pulp ground up and measured with Mutek
  
• Potlatch - streaming current detectors (zeta potential)
  
• HASimons - Stora is testing COD on purchased pulp
  

• Western - check vat level - found too low resulted in cycling
  
• Sterling - centre valve may be the problem
  
• P&T - Corrudec 3 seems to be a really finicky washer, so piped up filtrate to vacuum show to flood it and keep a seal
  

• SVP 98%
  
• R8 90%+, 89%, 87%, 96%, 92%, 92%, 95%
  

• Elk Falls, Mackenzie, Crofton, P&T, Howe Sound, Intercon, Kamloops - 50%
  
• Interox - concentration doesn't matter if you have good mixing
  
• Buckeye, Donohue, Irving, Canfor, Northwood, Domtar, Alpac, Ft. Frances, Marathon, Woodfibre, Grande Prairie, Celgar - diluted peroxide
  

• PG Pulp - .1% peroxide, 10.5 pH, get 1.5 points, stops reversion, use Na2SO3 to sour
  
• Western.1%, .5 points brightness gain, but no longer used
  
• Domtar - .05% to prevent reversion because using white water from paper machines
  
• Interox - Georgia Pacific- Palatka used for years
  
• Champion, Portland, 1 kg/t, gained 1 point, residual too small to measure
  

• Buckeye - control pH to keep H2S from generating
  

• Elk Falls - consistency indication but not on control
  
• HASimons - see notes from last year's BS Washing course
  

• Howe Sound - Dupont
  
• Mackenzie, Elk Falls - EIT
  
• Mallette - Clotan
  

• Harmac - similar due to logging second growth
  
• Elk Falls - sulphidity caused reduced tear, also found seasonal variation
  
• Kamloops - did fibre line audits through mill and compared to lab bleaches and measured strength properties to determine if something in the process has changed - found it was not the bleach plant
  
• HASimons - check residuals in digesters
  
• Liebergott - storage in chip pile can make a difference
  
• Espanola - good correlation between fibre length and tear
  
• Histed - any change in Do stage temperature? pH out of ClO2 stage?
  
• Harmac - did profile through plant similar to Kamloops, found no change since 10 years ago
  

• Howe Sound - raised temp from 75 to 90 and confirmed lab results
  
• Celgar - similar to Howe Sound
  
• Grande Prairie - did not find a benefit
  

• Crofton - 140 to 160, but now below 100 since increasing E2 caustic
  
• Liebergott - normally 150
  
• Harmac - 135
  
• Marathon -158
  
• Celgar - Tony did a survey for the bleaching committee - see minutes
  
• Histed - depends on lignin in pulp at Do stage
  

• Canfor - heat seal the ends
  
• Crofton, Marathon - fold the ends