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# OAR Box 1313 Prepped by LaTeia Shed



### Document

Number: 

# 45 ) ll-B-1 9
Docket Number: 

# A-88-0 2

Printed 6/12/20089:03:29AM

Sheet 45of 99P. 2 

# (§ ) A-88-0 2 MIDWES T RESEARC H INSTITUT E

450 5 Creedmoo r Roa

d Raleigh
. N.C
. 2761 2 Telephon e (919

) 781-575 0

Date : Marc h16 , 198 7

(Finalize dApri l 13 , 1987 ) Subject : Sit e Visit—Hamilto nStandar d

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 nBarke r 

# fe

To : Al 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 gathe r backgroun dInformatio n abou t th e chromi c aci danodizin g operation s a t thi s plan t an d t o asses s visuall y th e amoun t o f chromi c aci demission s generate db y chromi c ad d anodizin g operations . II . Plac e an

d Dat e Hamilto nStandar d Mai l Sto pI-B-3 A Bradle y Fiel dRoa d Windso r Locks , Connecticu t 0609 6 (203 ) 654-600 0 Decembe r 17 , 198 6
III . Attendee s Hamilto nStandar d Pau l LaQuerre , Manager-Facilitie s Complianc e Georg e Tompsett , Proces s Enginee r U . S . Environmenta l Protectio nAqenc y (EPA )
A l Vervaert , IS B

/P. 3

Midwes t Researc hInstitut e Robi nBarke r IV . Discussio n
W e arrive da t th e plan t a t 11:0 0 a.m . Th e visi t consiste do f a tou r o f th e anodizin g an

dplatin g sho pfollowe db y a discussio nabou t th e chromi c ad d anodizin g process . A . Genera l Hamilto nStandar d1 s a captiv e shopprimaril y engage d1 nchromi c a d danodizin g o f aircraf t part s suc ha s propelle r bulbs , gears , an d miscellaneou s smal l parts . Th e facilit y als o perform s sulfuri c ad d anodizin g an

dhardchromium , nickel , copper , an dcadmiu

m electroplating . Th e facilit y

employ s 8,00 0 peopl e an doperate s 3 shifts/day , 6 days/week . B . Proces s Descriptio n Ther e ar e tw

o chromi c ad danodizin g tank s a t thi s facility , arrange da s show

n1 nFigur e 1 . Bot htank s ar e 3. 6 meter s (m ) (1 2 fee t [ftl ) long , 1. 1 m

(3. 5 ft ) wide , an

d0.7 6 m

(2. 5 ft ) deep . Th e tank s bot h have a capacit y

o f 2,97 2 liter s (a ) (78 5 gallon s (gall) . Th e chromi c aci d anodizin g proces s Involve s th e followin g steps : 1 . Degrease ; 2 . Alkalin e cleaning ; 3 . Ho t wate r rinse ; 4 . Col dwate r rinse ; 5 . Chromi c ad danodizing ; 6 . Col dwate r rinse ; 7 . Nicke l acetat e seal ; 8 . Col dwate r rinse ; 9 . Ho t wate r rinse ; an d 10 . Blow

dry . Th e anodizin g bat hi s a wate r an dchromi c ad dsolution . Plan t personne l monito r th e bath s t o maintai nth e hexavalen t chromiu m concentratio na t 41. 6 t o 57. 2 gram s pe r lite r (g/a ) (12. 2 t o 16. 8 ounce s pe r gallo n[oz/gal] ) o f anodizin g solution . Sulfat e an dchlorid e concentration s ar e checke dperiodicall y t o ensur e tha t thes e parameter s ar e withi nth e norma l operatin g rang e fo r th e bath . I f thes e parameter s excee dth e norma l operatin g range , contaminatio no f th e bat h1 s indicated . Th e maximu m allowabl e value s fo r th e sulfat e concentratio nan d chlorid e concentratio nar e 0. 5 g/ a (0.0 7 oz/gal ) an d0. 2 g/ a (0.0 3 oz/gal) , respectively . Bot htank s ar e a1r-agitate dt o produc e a unifor m solution . Th e operatin g temperatur e 1 s 20° C (69°F) , 23° C (74°F) , o r 34° C (94°F ) dependin g upo nth e amoun t o f alloy s presen t 1 nth e aluminum . Th e highe r the amoun t o f alloys , th e lowe r th e operatin g temperature .



## 2LEGEND



### AIRFLO W ->

VENTILATIO N HOOD S

VENTILATIO N

HOOD S

< * Figur e 1 . Schemati c o f chromi c aci danodizin g tanks .

* •P. 5



### Th e tank s ar e equippe dwit h1,000-amper e rectifier s tha t have automati c control s t o ste pth e voltag e fro m 0 t o 4 0 volt s 1 n1 0 minute s an dthenmaintai nth e voltag e a t 4 0 volt s fo r 3 0 minutes . Th e aluminu m oxid e laye r tha t 1 s forme do nth e aluminu m durin g th e proces s 1 s ver y thi n (abou t 0.0 5 micrometer s [0.00 2 mils]) . C . Emissio nContro l Bot htank s ar e equippe dwit hdouble-side dlatera l hood s tha t ar e ducte doutsid e th e plant . A t th e time o f th e visi t onl y on e o f th e tank s wa s 1noperation . No mistin g wa s visibl e aroundth e anod e (workpiece ) o r cathod e (tank) . Th e ai r agitatio ncause da smal l amoun t o f th e solutio n t o be splashe dupInt o th e hood' s slots . Neithe r chemica l fume suppres sant s no r emissio ncontro l device s ar e use dt o contro l chromi c ad d emission s fro

m th e chromi c aci danodizin g tanks . V . Observation s Hamilto nStandar d1 s representativ e o f a captiv e sho ptha t perform s chromi c ad danodizin g o f aircraf t parts . A t th e time o f th e visit , n o visibl e mistin g wa s observe da t th e side s o f th e tank (cathode) o r around th e workpiec e (anode ) whil e th e tank s wer e 1 noperation . Ther e wa s n o chromi c ad dvisibl e o na piec e o f clea nwhit e pape r tha t wa s hel dove r on e o f th e bath s fo r a shor t perio do f time .



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