Spray chips with magnesium chloride to prevent freezing?

• will affect settling in recaust
• FMC – corrosion concern in recovery
• Consensus is that we do not want to add more chloride to mill

What order of addition of oxygen and peroxide?

• 7 peroxide first, 1 oxygen first, 1 simultaneous, 1 both

For HW pulp is there much variability in b*, and what is the cause?

• Domtar - Carryover of SO₂ excess ClO₂ also causes yellowing
• Paprican - normally can reduce it by adding a small amount of peroxide, did a trial adding 0.01% peroxide in HiD and reduced b*
• St Anne Nackawick and Gilles St. John may have some general information

Sesqui-saltcake filter titanium wire life?

• At least two years

Peroxide application in E2 stage – who uses more than 2 kg?

• KC – about 3 kg/t, none in E1

Do tradesmen work in gassy areas with SCBA.

• Repap – no problem if a leak, but don’t have areas that require SCBA under normal conditions
• Owen – limits that trip sensors are very low

• Other mills do not appear to require maintenance in areas which normally are gassy

Anybody using filter systems on showers?

• Repap - Kinney strainer
• Northwood – auto flush strainers
• Kamloops – Voith pressure screens for filtrate used fore wire cleaning showers, 4 thou, work continuously
• Harmac – 10 mesh, cleaned off weekly with high pressure water

Any mills banned smoking on the millsite?

• Harmac, Repap, Mackenzie, Crofton, Elk Falls

Do is now 20 minutes retention, considering switching to medium consistency, what experiences?

• HASimons – trouble converting tile HiD tank to MC, so would need another washer after HiD
• Howe Sound – rather than increase consistency they increased temperature 35⁰C to 55⁰C
• Northwood – converted, but did not see positive effect immediately, however saw benefit when went from fresh water to recycled Do filtrate
• Sandwell – chemical savings reported by Azim
• James MacLaren – 3% à 10%, reduced temp from 60⁰C à 50⁰C, reduced kappa factor 0.28 à 0.25, same brightness
• Kamloops – converted, no chemical savings seen, went from upflow to upflow-downflow with ring dilution, take Do filtrate back, scrub top of tower, no residual in vat

Who uses wireless bales?

• Prince George has used for a number of years
• Harmac – one customer will not take wires, so stack unwired bales on pallets
• Crestbrook – inquiries from US about animal products in pulp (mad cow disease), so need to be aware if glue contains animal products
• AlPac – gluing bales would slow down production

E2p stage had high brightness on D2, but did not show up on machine – anyone else?

• No-one saw this drop in brightness
• Crestbrook – sees increase from D2 to machine
• KC and Cariboo also see increase, even without peroxide on E2
• Northwood – use E2p
• Ross – E2 stage is not best place for increase in final brightness, even though it is good for reducing chemical cost

Tri-butyl phosphate defoamer is now added to methanol, saw step change in generator liqour test result, anybody else? (1 liter / 5000 USG = 35 ppm)

• Sterling – if you had foam before, then level measurement may have been fooled, now is reading correctly. If liquor boiling point changed, then you had a liquor change.
• Check pressure transmitter, steam consumption, actual level

Eop CEK number predictor analyzer?

• Intercon has a sensor, but it may be for peroxide control

Brightness meters have coating problem, does anybody else?

• Harmac – adjust D1 sensitivity with time
• Repap – couldn’t make it work
• U of T – acoustic cleaner available (Kajaani?)
• Mackenzie – do not have coating problem on brightness sensors on Do, D1 or D2

How high a temperature can you go in D1 and D2 to make high brightness (93%)?

• U of T – steam blowback?
• Owen – could get FRP delamination at high temperature (supplier says 90⁰C)
• Harmac – 175⁰F the FRP gets soft, pulp erodes it, so needs to be relined every few years
• Northwood – no benefit on final brightness going to high temperature because run out of residual

Need 0.2 lbs/t defoamer on ECF on D1 stage, but none when 70% substitution. Why?

• Harmac – switching 50% to 100% needed defoamer on Do

pH control on D1?

• Acid 4 mills, Caustic 8 plus one switching to caustic, Both 3, None 2

pH control on D2?

• Acid 3, caustic 4, none 3

How many measure pH on ClO2?

• 3

There are false claims for a "magic" chemical being marketed. It is said to be stabilized ClO2 at 25% - bogus claims! Sales demonstrations are hazardous to your conference room and to your personnel. Contains sodium chlorite.

• Heimburger – there are safe generators that can generate ClO2 from chlorite
• Sterling – check their WEB site for more information

Kajaani post Kajaani sensors were in automatic before ECF, now running in manual because can’t get to work. Anyone else?

• Howe Sound – post brightness no longer makes sense since on ECF
• Kajaani says the same thing – no longer recommend post sensors
• Harmac removed post sensors
• Thurso is implementing kappa control instead
• Slight residual at end of stage at Powell River

Had an acid spill last week and are questioning integrity of hoses.

• Crestbrook – found that if Flex Wing hoses are bent they will break
• Owen – hydro static test every year? (No, replace annually)
• Repap – hydro test annually
• Cominco, CXY – need to cap hoses when they are not in normal use to avoid corrosion

• Different experience levels, significant level of trust here, lots of interaction, this is Problem Based Learning, which is different from the lecture based learning at the Bleaching Course.

Why do mills send members to this committee meeting?

• Immediate value for the mill 20
• Opportunity of seeing what other mills are doing 20
• Habit (because you came last time) 0
• Orders from above 1 (Dennis’ wife kicked him out)
• No course fee some
• Doesn’t have a large social component – go to work 1
• Technical presentation, Problem sessions most

How many mills using CE Kappa as a routine test?

• 5

Anybody measured TRS, CO in vent gases off oxygen delignification blow tank?

• Harmac – have measured
• U of T – NCASI has done a huge survey of emissions, they may have data. H2S will survive a recovery boiler, so it makes sense that it won’t be oxidized in an oxygen reactor

Did TOX in pulp reduce when switching to oxygen delignification?

• Harmac – no change, noisy background
• Crofton measures TOX, wait until their oxygen bleaching is complete

How to lower TOX in pulp?

• Cariboo – reduce kappa factor, then use peroxide in HiD