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# OAR Box 

# 1814 Prepped by Ollie Stewart



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Number: 

# 45 ) ll-B-2 3

Docket Number: 

# A-88-0 2

Printed 11/7/20087:22:08AM

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## A-88-0 2 MIDWES T RESEARC H INSTITUT I

450 5 Creeamoo rRoa

. Raleig h N C 276 1 Telephon e (919 ) 781-57 5

Date : Marc h16 , 198 7

(Revise dan

d update dfro

m Ma y 21 , 1985 , Tri pReport ) (Finalize dApri l 2 , 1987 ) Subject : Sit e Visit—Delc o Product s Division , Genera l Motor s Corporatio n

Chromiu m Electroplatin g NESHA P EPA Contrac t 68-02-3817 ; ESE D Projec t 85/02 a MR I Projec t 7717- K
From : Robi nBarker j \ hfi
To : A l Vervaer t

ESED/ISB/SS S (MD-13 ) U . S . Environmenta l Protectio nAgenc y Researc hTriangl e Park , N.C . 2771 1
I . Purpos e Th e purpos e o f thi s sit e visi t wa s t o determin e th e suitabilit y o f th e decorativ e chromiu m platin g operation s fo r uncontrolle dchromium emission s testing . Th e backgroun dinformatio non th e decorativ e chromiu m platin g operation s a t thi s plan t wa s gathere d1n a previou s visi t t o th e plan t o n Marc h15 , 1985 . II . Place and Dat e Delc o Product s Divisio n Genera l Motor s Corporatio n Livoni a Plan t 1300 0 Eckle s Roa d Livonia , Michiga n4815 1 (313 ) 464-515 5
Januar y 21 , 198 7
III . Attendee s Delc o Product s Division , Genera l Motor s Corporatio n(Delco )
Harr y Cameron , A1 r Pollutio nContro l Superviso r Larr y Siersma , Environmenta l Contro l Enginee r U . S . Environmenta l Protectio nAgenc y (EPA )
A l Vervaert , IS B

/P. 3

Midwes t Researc hInstitut e (MRI ) Robi nBarke r IV . Discussio n Th e visi t bega nwit ha discussio nabou t th e emissio ncontro l syste m 1nplac e o nth e decorativ e chromiu m platin g line s a t th e Delc o Product s plant . Th e discussio nwa s followe db y a tou r o f th e platin g facility . A . Genera l Th e Delc o Product s plan t 1 s anorigina l equipmen t manufacturer o f bumper s fo r th e automotiv e Industry . Ther e ar e fiv e decorativ e chromiu m platin g line s a t thi s plant : Lin e Nos . 1 throug h3 wer e Installe d fro m 2 7 t o 3 2 year s ago , an

dLin e Nos . 4 an

d5 wer e Installe d 1 7 year s ago . Th e plan t operate s tw

o shift s pe r day , 5 day s pe r week . B . Proces s Eac hplatin g lin e consist s o f abou t 2 0 tank s tha t contai nvariou s platin g an

dcleanin g solutions . Th e line s ar e service db y automatically controlle dconveyor s tha t transfe r rack s containin g upt o 1 4 bumper s t o eac htan k 1 nsequence . Th e chromiu m platin g segmen t o f eac hlin e consist s o f a platin g tank an

dsevera l rins e tanks . Eac hchromiu

m platin g tank measure s 6.1 0 meter s (m ) (2 0 fee t [ft] ) 1 nlength , 3.6 6 m

(1 2 ft ) I nwidth , an d2.7 4 m ( 9 ft ) 1ndept han

d1 s divide dInt o thre e cell s tha t ar e 2.0 4 m (6. 7 ft ) 1 nlength . Eac h 3-celle d tank hold s 64,36 0 liter s (a ) (17,00 0 gallon s [gal] ) o f platin g solution , whic hcontain s chromi c ad d 1na concentratio no f 24 7 t o 37 4 gram s pe r lite r (3 3 t o 5 0 ounce s pe r gallon ) o f water . Sulfuri c ad d 1 s use da s a catalys t 1 na 180: 1 (chromi c ad dt o sulfuri c acid ) ratio . Th e solution s have bee ndispose do f onc e sinc e the y wer e originall y

mad e up ; makeu pwate r an

dchromi c ad dar e adde dcontinuall y t o replac e losse s du e t o evaporatio nan d dragout . Th e tota l chromi c ad dconsumptio na t thi s plan t 1 s 6,80 4 kilogram s (15,00 0 pounds ) pe r month . Typically , a rac k remain s 1 non e cel l o f a chromiu m platin g tank fo r a littl e ove r 2 minute s t o receiv e a chromiu m plat e thicknes s o f 0.30 5 micrometer s (0.01 2 mils) . Th e electrode s 1neac hcel l ar e charge d b y two separat e transformer/rectifiers . Durin g a typica l platin g cycle , th e tan k operate s a t 1 6 t o 1 7 volt s (V ) an d8,50 0 t o 10,00 0 ampere s (A) . Th e electrica l setting s ar e determine db y th e require dcurren t densit y fo r a particula r rac k o f bumpers . Typica l curren t densitie s ar e 1nth e rang e o f 1,61 5 t o 2,15 0 ampere s pe r squar e mete r (15 0 t o 20 0 ampere s pe r squar e foot) . C . Emissio nContro l Plan t personne l sai d tha t abou t 9 9 percen t o f th e ga s emitte dfro m a chromiu m platin g tan k 1 s du e t o th e formatio no f hydroge nga s bubble s a t



# - eP. 4

th e surfac e o f th e Item s bein g plate d(cathode) . Th e remainin g 1 percen t 1 s cause db

y th e formatio no f oxyge nga s a t th e surfac e o f th e lea d anodes . Th e plan t believe s operatin g curren t i s th e predominan t facto r affectin g emission s fro m a typica l tank . Th e ventilatio nsystem o nth e tank s appeare dt o b e effectivel y drawin g mis t int o th e contro l syste m durin g th e visit . Eac hchromiu m platin g tan k ha s two single-side dlatera l hood s o nth e end s o f th e tank an dtw o double-side dlatera l hood s betwee neac hplatin g cel l tha t draw emission s fro

m alon g th e 3. 7 (|2-ft ) widt h(se e Figur e 1) . Abou t 850 3 cub1 c meter s pe r minut e ( m /min ) (30,00 0 cubi c fee t pe r minut e [f t /m1n] ) o f ai r ar e draw nfro m th e platin g tank s o nLin e Nos . 1 an d3 . Abou t 99 0 m

/m1 n(35,00 0 f t /m1n ) ar e draw nfro m th e tank s o nLin e Nos . 4 an d5 . Th e Occupationa l Safet y an dHealt hAdministratio n(OSHA ) require s tha t ambien t chromiu

m level s remai nbelow 0.0 5 milligram s pe r cubi c mete r (mg/ m ) (2.19x10 " grain s pe r cubi c foo t [gr/f t ]) , an dmonthl y

monitorin g ha s show nth e level s a t thi s plan t t o b e unde r 0.0 2 mg/ m (8.74x1 0 gr/f t ) . Thi s plan t ha s ha

dabou t si xdifferen t contro l devic e configuration s sinc e 1 t bega noperating . Th e emissio ncontro l system 1 s uniqu e an

d combine s bot hoff-the-shel f an dspeciall y

designe dequipment . Eac hsystem route s exhaus t gase s fro m on e chromiu

m platin g tank throug ha packed-be d spra y towe r scrubber , animpingemen t mis t eliminator , a 2-1nch-th1c k polypropylen e blanket , a fan , a wate r impingemen t tank , a second Impingemen t mis t eliminator , an da 2-1nch-th1c k fiberglas s blanket . Eac hscrubbe r i s 4.8 8 m (1 6 ft ) hig han

d2.7 4 m

( 9 ft ) 1 ndiamete r an dha s 1.2 2 m

( 4 ft ) o f "Maspac® " packing . Ther e i s a 6-1nc hpressur e dro pacros s eac hscrubber . Th e Maspac ®packin g i s mad e o f Saran ®(Do w Chemical ) an

dha s bee n1nservic e sinc e 1975 . Prio r t o 1975 , poly propylen e wa s use da s a packin g material , bu t thi s materia l disintegrate d an dha dt o be replace dafte r onl y 1. 5 years . Chromi c ad ddisintegrate s certai nplastic s a s wel l a s causin g corrosio n1nmeta l ducts . Part s o f th e contro l system

tha t come int o contac t wit hchromi c ad dmis t ar e mad e o f titaniu

m o r fiberglass-reinforce dPV C t o withstan dth e corrosiv e aci d attack . Th e scrubbe r packin g i s flushe dwit hclea nwate r fo r 1 5 minute s eac h week . Condensat e fro m th e scrubbe r an

dspen t wate r fro

m th e wate r Impingemen t tan k ar e draine dt o a nevaporato r extensio ntank . Th e concentrat e fro

m th e evaporato r extensio ntank 1 s returne dt o th e chromiu m platin g tank a s makeu psolution . Plan t personne l estimate dtha t th e efficienc y

o f chromiu

m utilizatio na t thi s plan t Increase d fro m 1 0 percen t t o ove r 9 0 percen t whe nthi s recover y syste m wa s Installed . Th e scrubbe r als o serve s a s th e coolin g devic e fo r controllin g th e temperatur e o f th e platin g bath . Th e exces s hea t 1nth e platin g tank 1 s transferre dt o th e scrubbin g liqui dvi a a I1qu1d/liqu1 d hea t exchanger . Th e warme dscrubbin g liqui denter s th e scrubbe r abov e th e towe r packin g an dflow s b

y gravit y dow nthroug hth e packing . Th e contaminate dai r tha t 1 s draw nfro m th e platin g tank enter s th e scrubbe r below th e towe r packin gAIRFLO W LEGEN D

^ii d FLOO R

1 0 FA N 

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I VAI'UI'AluK , . 1 Kin.1. 1 l PLATIN G TAN K

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Figur e 1 . Schemati c o f decorativ e chromium platin g tank . ^P. 6

an d1 s draw

nu pthroughth e packin g b y th e exhaus t fan . Th e liqui dwashe s th e chrom e contaminatio nou t o f th e ai r stream an dals o warm s th e ai r stream , resultin g 1 nth e absorbtio n(evaporation ) o f 15. 1 i ( 4 gal ) o f liqui d1 nt o th e ai r stream . Thi s evaporatio nproces s cool s th e scrubbin g liquid . Th e coole dliqui d1 s recirculate dt o th e hea t exchange r an d reheated . Th e remova l efficienc y o f th e contro l system o non e o f th e tank s wa s teste d1 n1979 . A

cop y o f th e tes t repor t wa s obtaine db y EPA durin g th e visit . Port s o nth e Inle t sid e o f th e scrubbe r ar e stil l 1nplace ; however , th e duc t containin g port s o nth e outle t sid e ha s bee nreplace d sinc e th e tes t wa s performed . No visibl e emission s wer e observe dexitin g th e contro l device . D . Conclusion s Delc o 1 s representativ e o f a large-siz e captiv e sho ptha t perform s decorativ e chromiu

m electroplatin g o f automobil e bumpers . Suitabl e tes t port s ar e locate da t th e inle t t o th e evaporator/scrubber , th e platin g bat hdoe s no t contai na fume suppressant , an dth e amoun t o f wor k plate d woul dgenerat e chromiu m emission s adequat e fo r testing . Therefore , 1 t 1 s recommende dtha t emissio ntestin g be performe da t th e Inle t o f th e evaporator/scrubbe r t o obtai nanuncontrolle demissio nleve l fo r decorativ e chromiu

m electroplatin g operations . V . Referenc e 1 . Memo fro

m Duletsky , B. , MRI , t o Vervaert , A. , EPA/ISB . Ma y 21 , 1985 . Tri prepor t fo r Chevrolet-Pontlac-Canad a Group , Livonia , Michigan , pp . 1-5 .



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