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# OAR Box 

# 1313 Preppedby LaTeiaShed



### Document

Number: 

# 10 ) l-B- 3 Docket Number: 

# A-88-0 2

Printed 6/12/20089:03:27AM

Sheet 10of 99P. 2

• H 

# 0

Date : February25 , 198 5

(Finalize d Apri l 2 , 1985 ) 

## A-88-0 2 MIDWES TRESEARC H INSTITUT E •3T
- o- 3 450 5 Creedmoo rRoa d Raleigh , N.C

. 2761 2 Telephon e (919 ) 781-575 0 

# FINA L 

# FIL EOOP ?

Subject : Sit e Visit--Gibb s Plating Compan y Surve yo f Chromiu

mEmissio n Sources—Chromiu m Plating EP AContrac t 68-02-3817 ; ESE D Projec t 85/0 2 MR I Projec t 7711- L From : Barb Duletsk y&u^- * To : A

l Vervaer t ESED/ISB/SS S (MD-13 ) U . S . Environmenta l Protectio n Agenc y Researc h Triangl e Park , N.C . 2771 1 I . Purpos e Th e purpos e o f thi s sit e visi t wa s twofold : (1 ) t o gathe r backgroun

d informatio n on thi s chromiu mplating plant , an d (2 ) t o determin e th e suitabilit yo f thi s plan t fo r chromiu memission s testing
. II . Plac e an

d Dat e Gibb s Plating Compan y 521 0 Hovi s Road Charlotte , N.C . 2820 8 (704 ) 392-738 2 Decembe r 20 , 198 4 III . Attendee s Gibb s Plating Compan y E d Gibbs , Presiden t Doug Fairchild , Plan t Manage r U . S . Environmenta l Protectio n Agenc y(EPA ) A l Vervaert , Lea

d Enginee r Midwes t Researc h Institut e (MRI ) Bar b Duletsk

y IV . Discussio n W e arrive d a t 9:4 0 a.m . a t the plant , wher e w e wer e greete d b y Messrs . E d Gibb s an d Doug Fairchild
. Th e plan t visi t consiste d o f a discussio n abou t chromiu mplating , followe d b ya guide d tou r o f the facility
. 

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Principa l Laboratorie s 42 5 Volke rBoulevard

. Kansa s City

. Missour i 6411 0P. 3

A . Genera l Th e Gibb s Plating Co . facilit yi s a n average-size d job sho p involve d i n the hard chromiu mplating o f items such a s pum p parts , textil e manu facturing equipmen t parts , an d othe r machinerycomponents . Othe r operation s performe d a t the plan t includ e zin c barrel-plating , cadmiu m plating , coppe r plating , an d chromating
. Ther e ar e 1 7 full-time employee s working i n the plant , on e o f whomi s responsibl e fo r operating the chromiu mplating tank . Abou t 2 5 percen t o f th e company' s tota l annua l sale s i s a resul t o f th e chromiu mplating operations
. Th e Gibb s Plating Co . move d t o the facilit yw e visite d abou t a yea r ago . I t ha

d previousl yoperate d a t anothe r locatio n i n Charlotte , Nort h Carolina
. Ove r th e pas t year , the compan yha s installe d electrica l an d plumbing fixtures , relocate d severa l planting tank s fro mthei r previou s location , an d acquire d a newautomate d zin c plating tank ; however , the relocatio n i s no t complete . Presently , th e plan t operate s 1 shift/day , 5 days/week . B . Proces s Informatio n 1 . Hard Chromiu

mPlating
. Currently , th e compan yoperate s on e hard chromiu

mplating tank . Th e tan k measure s 6 fee t (ft ) in length , 3 f t i n width , 4 f t i n depth , an d hold s abou t 45 0 gallon s (gal ) o f plating solution
. Anothe r tan k wa s expecte d t o g o on-lin e withi n the nex t 9 0 days . Thi s secon d tan k measure s 2 1 f t in length , 3 f t i n width , an d 7 f t i n depth . Th e plating solutio n consist s o f chromi c aci d (Cr0 3 ) in a concen tratio n o f 3 2 ounces/gallo n (oz/gal) . Th e aci d i s manufacture d b y Allie d Chemica l an

d supplie d b

yM & T Chemica l Company . Historically , the compan

yha s used betwee n 12,00 0 an d 15,00 0 pound s (lb ) o f dr ychromi c aci d annuall yfo r thi s chromiu mplating tank . (Mr . Gibb s sai d tha t chromi c aci d consumptio n i s a good indicato r o f the siz e o f a chromiu m plating facility. ) Sulfuri c aci d (H 2 S0 4 ) i s use d a s a catalys t in the plating solution
. I t i s use d in the proportio n o f 1 par t o f sulfuri c aci d t o 10 0 part s o f chromi c acid
. Mr . Gibb s indicate d tha t fluorid e i s no t used a s a chromiu mcatalys t fo r har

d chromiu

mplating a t thi s plan t becaus e o f it s tendenc yt o corrod e unp'rotecte d surface s o f stee l part s tha t remai n in th e tan k fo r severa l hour s t o obtai n thicke r deposit s o f chromium
. Asampl e o f th e plating solutio n i s teste d weekl yt o ensur e tha t the prope r concentratio n o f constituent s i s maintained
. Mr . Gibb s note d tha t a plating tan k can operat e fo r a s lon g a s 2 0 year s withou t needing t o be emptie d an d cleaned , providing tha t the buildu p o f con taminant s such a s coppe r an d iron in the tank s i s avoided
. Th e plating solutio n i s normall ymaintaine d a t 125°F . The temperatur e i s regulate d b ybot h a

n electri c heating syste man d a wate r cooling system . Th e plating tan k i s energize d b

ya singl e transformer / rectifier
. Maximu

moperating voltag e an d curren t ar e 9 volt s (V ) an dP. 4

3,00 0 ampere s (amps) , respectively . Typica l job s requir e tha t part s remai ni nth e tan kfo r 1 t o 4 hours ; however , some job s ma y requir e tha t part s b e plate da s long a s 2 4 hours . Thi s typ e o f jo binvolve s leavin g part s i nth e tan kovernigh t an doccur s onl y abou t onc e a week . Afte r bein g plated , th e part s ar e rinse dove r th e to po f th e platin g tan kwit hwate r fro m a hose . Thi s allow s exces s platin g solutio n o nth e part s t o drai nbac kint o th e platin g tank , thu s reducin g drag-out . ("Drag-out " refer s t o th e carry-ove r o f platin g solutio nwit hpart s whe n the y ar e transferre dfro m on e tan kt o another. ) Afte r th e initia l rinse , th e part s ar e transferre dt o a nadjacen t rinse tan kwher e the y ar e submerged . Afte r rinsing , th e part s ar e air-dryed , buffed , and packe dfo r shipment . 2 . Chromating . Gibb s Platin g Co . operate s a chromatin g tan kbu t doe s no t conside r i t t o b e a sourc e o f chromiu m emissions . Th e chromi c aci dsolutio ninth e tan ki s ver y dilute , containin g onl y abou t 1 percen t o f th e amoun t o f chromi c aci dtha t i s use di nth e har dchromiu m platin g solution . Chromatin g i s performe dfo r colorin g purpose s only . Ther e i s no electri c curren t i nth e tank , andth e proces s i s performe da t roo m temperature . Becaus e no mis t i s generated , there ar e no emission s t o captur e o r control . 3 . Decorativ e Chromiu m Plating . Thi s plan t i s no t involve di n decorativ e chromiu

m plating , bu t Mr . Fairchil dprovide dth e followin g informatio nbase donhi s ow nexperience . I ndecorativ e chromiu m plating , a thi nlaye r o f chromium (abou t 0.0 1 mil ) i s applie dove r a nicke l coate dsubstrat e t o provid e a bright , tarnish-resistan t surface . Becaus e th e laye r o f chromiu m plat e i s ver y thin , part s onl y

nee dt o b e i nth e chromi c aci dsolutio n1 0 t o 3 0 minutes . Decorativ e plater s usuall y proces s a hig hvolume o f part s andar e likel y t o hav e automate dlines . A variet y o f substrate s ca nb e chromiu m plated , bu t some o f the m requir e specia l pretreatment . Fo r instance , aluminu m part s mus t b e plate dwit hzin c befor e bein g plate dwit hchromiu m becaus e chromiu

m doe s no t adher e wel l t o aluminum . Also , plasti c part s requir e chemica l pretreatmen t befor e the y ca nb e effectivel y

chromiu

m plated . Plasti c i s no t conductiv e and , therefore , canno t attrac t chromiu m ion s i nth e electrolyti c solution . Abou t hal f o f th e platin g cycl e time fo r plasti c i s spen t renderin g th e part s conductive . Mos t o f th e plasti c tha t i s plate dconsist s o f acrylonitrile-butadiene-styren e (ABS) . Th e butadien e i s sensitiv e t o solven t attack ; therefore , th e firs t ste pi nplatin g plasti c involve s etchin g i t i na stron g chromi c aci dsolutio ntha t i s heate dt o 71° C (160°F) . Thi s etchin g leave s microscopi c hole s o nth e surfac e o f th e plasti c par t wher e th e aci dha s dissolve dth e butadiene . Th e par t i s the ntreate dwit hpaladium , whic hi s adsorbe dinth e hole s onth e surface . Th e paladiu

m attract s nicke l o r coppe r molecule s fro m anelectroles s solution , thereby

formin g a continuous , conductiv e surface . Subsequen tP. 5

step s includ e electrolyti c coppe r plating , electrolyti c nicke l plating , an d the n electrolyti c chromium plating
. I n dippin g plasti c part s int o th e variou s solutions , th e arrange men t o f th e part s o n th e rac k i s critical
. Becaus e th e platin g temperature s ar e high , part s mus t b e arrange d i n a wa ytha t doe s no t appl ystres s i n anydirectio n s o tha t warpin g doe s no t occur . O n th e othe r hand , goo d contac t mus t b e achieve d betwee n th e par t surfac e an d th e rac k s o tha t th e par t ca n conduc t electricit yand , thus , attrac t meta l ion s fro mth e electrolyti c platin g solutions
. C . Pollutio n Contro l 1 . Emission s Control . Mis t i s generate d i n th e har d chromiu m plating tan k du e t o th e evaporatio n o f wate r an d th e formatio n o f hydroge n ga s o n th e surfac e o f th e cathode s (parts) . Th e mis t carrie s entraine d hexavalen t chromiu m(Cr+ 6 ) molecule s a s i t escape s fro mth e surfac e o f th e platin g solution
. Ther e wa s visibl e misti'n g fro mth e har d chromiu m tan k durin g th e plan t visi t bu t n o visibl e mistin g fro mth e chromatin g tank . Ther e i s nothin g o n o r i n th e plating tank s t o preven t misting
. Althoug hMr . Gibb s i s familia r wit hth e us e o f polypropylen e balls , an d chemica l foam s t o retar d misting , neithe r i s use d a t th e plan t becaus e h e doe s no t conside r eithe r metho d t o b e ver yeffective
. Th e chemica l tha t produce s th e foam laye r i s ver yexpensiv e an d cause s a pitte d appearanc e o n th e plate d parts . Also , th e agitatio n o f th e bat hdu e t o th e bubblin g o f hydroge n ga s fro m th e surfac e o f th e cathode s i s usuall y sufficien t t o displac e a laye r o f ball s o r foamfro maroun d th e cathodes . Th e har d chromiumplatin g tan k i s equippe d wit ha side-draf t hoo d alon g on e side
. An induce d draf t fa n i s use d t o dra wabou t 10,00 0 cubi c feet/minut e (ftVmin ) o f ai r acros s 1 8 squar e fee t (ft 2 ) o f tan k surfac e are a an d th e throug hth e hood . Th e fa n i s upstrea mo f a Dual l inclined , packed-be d fum e scrubber . Th e scrubbe r collect s chromiumemission s whe n th e mis t impinge s o n th e packed-be d plates . Th e contro l system , whic h include s th e scrubber , ductwork , hood , an d fan , wa s installe d fo r abou t $14,00 0 an d i s shown i n Figur e 1 . Wate r i s recirculate d continuousl yt o flus hth e scrubbe r plates . Whe n th e chromiumconcentratio n i n th e wate r reache s a certai n level , th e wate r i s draine d and treate d b ya n on-sit e effluen t treatmen t system . Th e syste mi s designe d s o tha t eventuall yth e wate r wil l b e emptie d int o th e har d chromiu mplatin g tank , bu t th e pipin g t o accommodat e thi s ha s no t bee n installe d yet . I t i s expecte d t o b e installe d withi n th e nex t 9 0 days . Emission s fro mth e secon d har d chromiu m platin g tan k tha t i s t o b e installe d wil l als o b e treate d b ya scrubber . Thes e emission s wil l b e ducte d t o th e existin g scrubbe r i f th e compan ydetermine s tha t thi s scrubbe r ca n accommodat e ai r flow s fro mbot htanks . Otherwise , a ne w scrubbe r wil l b e designe d an d installe d b yeithe r Dual l o r KCH .

/.P. 6

T O ATflOSPHERE

SCRUBBER

HOLDING

TANK

T O EFFLUEN T TREATMEN T

HAR DCHROME PLATINGTANK

Figur e 1 . Contro l syste m o nhar dchrom e platin g tank .



### S.P. 7

2 . Effluen t Treatment . Th e company ha s permissio nt o direc t it s effluent t o th e local , publicly-owne dwastewate r treatmen t plant . Th e company i s i nth e process , however , o f installin g it s ow ncomplet e effluen t treatmen t system . Th e system include s a sodiu

m bisulfit e tan k fo r th e reductio no f hexavalen t chromiu m i nth e chromiu

m platin g waste s t o trivalen t chromium . Othe r processe s bein g installe dfo r the , treatmen t o f combine dwastewate r fro m th e plan t ar e a pHneutralizatio ntank , a flocculatio ntank , a primar y clarifier , anda sandfilter . Mr . Fairchil d i s overseein g th e installatio no f thi s system , whic hrepresent s a tota l capita l investmen t o f abou t $100,000 . Currently , sludg e fro m th e effluen t treatmen t system i s no t considere dt o b e hazardous , s o i t ca nb e dispose do f a t a loca l sanitar y landfill . However , becaus e o f th e heav y meta l conten t o f th e sludge , Mr . Gibb s expect s thi s nonhazardou s statu s t o chang e soon . Whe nth e sludg e i s officiall y

considere dt o b e hazardous , i t wil l hav e t o b e haule dt o Pinewood , Sout hCarolina , fo r disposa l a t a secur e sanitar y landfill . D . Conclusion s Th e tri pt o Gibb s Platin g Co . wa s ver y informative . Becaus e o f Mr . Gibbs ' involvemen t wit hth e America nElectroplater s Societ y (AES ) andth e Nationa l Associatio no f Meta l Finisher s (NAMF) , he wa s abl e t o suppl y informatio nonth e chromiu m platin g industr y

i ngeneral . I t wa s suggeste dtha t th e projec t tea m attendth e AES/EP A

conferenc e inOrlando , Florida , inJanuar y

198 5 fo r mor e informatio nonth e industry . Thi s plan t i s representativ e o f othe r jo bshop s performin g har d chromiu m plating . Emission s fro m th e platin g tan kwer e observe dt o b e effectivel y

draw nint o th e hoo dalon g th e bac kedge . Th e fum e scrubbe r wa s effectiv e i ncollectin g emissions , a s evidence db y th e clea nexhaus t stream . Inle t andoutle t testin g o f th e fume scrubbe r i s feasible ; however , a por t woul dnee dt o b e installe da t th e inle t locatio nan da stac kwoul dnee dt o b e constructe da t th e outle t location . Tes t dat a fro m thi s plan t coul db e use dt o determin e uncontrolle demission s fro m a typica l har dchromiu

m platin g tan kandth e performanc e o f a fum e scrubbe r incontrollin g thos e emissions .