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# OAR Box 

# 1313 Preppedby LaTeiaShed



### Document

Number: 

# 16 ) l-B- 9
Docket Number: 

# A-88-0 2

Printed 6/12/20089:03:27

AM Sheet 16 of 99P. 2

MIDWES T RESEARC H INSTITUT E

J50 5 Creeamoo rRoa o Raleign

. N.C

. 2761 2 Teleononei9l9 ) 781-575 0 

## A-88-0 2

Date : Ma y

20 , 198 5 (Finalize dNovembe r 4 , 1985 ) - Subject : Sit e Visit—Moder nHar dChrome Servic e Company

Surve y o f Chromium

Emission s Sources—Chromiu m Platin g EP A Contrac t 68-02-3817 ; ESE D Projec t 85/0 2 MR I Projec t 7711- L From : Bar bDuletsky f>^^ - 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 th e sit e visi t wa s t o gathe r backgroun dinformatio no n th e chromiu

m platin g operatio na t th e subjec t plan t and t o determin e th e suitabilit y

o f th e plan t fo r chromium emission s testing . II . Plac e an

d Dat e Moder nHar dChrome Servic e Company 1288 0 Eas t Nin e Mil e Roa d.. . Warren , Michiga n4808 9 •" V (313 ) 371-033 0 . ' »- - ' Z l I Marc h14 , 198 5 

## ;m 18199 1
III . Attendee s Moder nHar dChrome Servic e Compan y •- . ' " Charle s Nicholl , Vic e Presiden t Midwes t Researc hInstitut e Bar bDuletsky IV . Discussio n I arrive da t th e plan t a t 9:3 0 a.m . an d me t wit hMr . Nichol l t o discus s har dchromiu m platin g an

d emissio ncontro l techiques . Followin g this , Mr . Nichol l gav e m e a tou r o f th e Moder nHardChrom e facility , durin g whic hh e provide dspecifi c informatio nabou t th e plant . ' i J

/ Principa l Laboratorie s 42 5 Volke rBoulevard

. Kansa s City

. Missour i 6411 0P. 3

A . Genera l Accordin g t o Mr . Nicholl , Moder nHar dChrome i s on e o f th e larges t har dchromium

platin g jobshop s i nth e country . Th e company ha s bee n operatin g a t thi s sit e sinc e 1952 . Presently , ther e ar e 7 5 employees , an d th e plan t operate s 3 shift s pe r day , 5 day s pe r week . Abou t 6 0 percen t o f th e company' s sale s i s du e t o har dchromiu m plating , an

dth e res t i s du e to-grinding , machining , an delectroles s nicke l plating . Har dchromiu

m platin g i s performe dfo r th e automotiv e industry , th e stee l foundr y

industry , an

dvariou s othe r industries . Th e plan t plate s item s rangin g fro

m 17-ft-lon g industria l roller s t o 2-inch-lon g scre w machin e parts . Items ma y b e plate dfo r an

y o f severa l reasons : (1 ) t o impar t specifi c propertie s suc ha s hardness , corrosio nresistance , an da lo w coefficien t o f frictio nt o th e surface s o f newl y manufacture ditems , (2 ) t o correc t error s mad e i nmachinin g ne w items , o r (3 ) t o rebuil d surface s o f use ditem s tha t hav e bee nwor ndown . B . Proces s Ther e ar e 1 6 hardchromiu m platin g tank s a t thi s facility , rangin g 1 n capacit y from 40 0 t o 3,29 0 gallons . Ther e i s on e vertica l tank equippe d wit ha mechanica l hois t use dt o plat e industria l rollers . Th e res t o f th e tank s ar e oriente dhorizontall y an dar e manuall y

operated . Th e specifi c dimension s o f th e tank s ar e show ni nTabl e 1 . Th e solutio n1 nth e tank s contain s chromi c ad di na concentratio no f 3 0 t o 3 3 ounce s pe r gallo n(oz/gal) . Sulfuri c aci di s use da s a catalys t i na 100 : 1 (chromi c aci dt o sulfuri c acid ) ratio . Th e plan t use s 60,00 0 pound s o f chromi c aci di na typica l year . Operatin g parameter s ar e highl y variabl e becaus e o f th e wid e variet y o f item s plated . Platin g time s rang e fro m 4 minute s t o 4 days , dependin g o nth e thicknes s o f chromiu m deposi t required , wit hth e averag e platin g time bein g betwee n5 an d8 hours . Th e temperatur e o f th e platin g solutio n i s maintaine da t 125 ° t o 140°F . Eac htank i s energize db y a separat e transformer/rectifie r set . Th e require dvoltag e i nth e tank s depend s o n th e distanc e betwee nth e electrode s an dth e items t o b e plated . A s thi s distanc e increases , th e voltag e mus t als o increas e t o overcom e th e highe r resistanc e an

dmaintai nth e desire dcurrent . The electrode s hav e th e capacit y t o draw

3 t o 6 volt s (V) , bu t usuall y operat e a t abou t 5 V . Curren t 1 s a functio no f th e siz e an dshap e o f the ite

m t o b e plated . Th e tank s hav e th e capacit y t o dra w

3,00 0 t o 15,00 0 ampere s (A) , althoug hth e operatin g curren t i s usuall y betwee n5,00 0 an

d10,00 0 A . Mr . Nichol l explaine dtha t highe r curren t densitie s increas e th e abilit y o f th e stee l t o attrac t chromiu m electrolyte , enablin g chromiu m t o b e plate dont o area s tha t ar e farthe r fro m th e electrodes . Figur e 1 show s th e differen t electrica l field s tha t resul t whe nthe sam e curren t densit y i s use dt o plat e thre e differentl y shape dsurfaces . Th e exterio r corne r ca nb e adequatel y

plate db

y applyin g a curren t densit y o f 0. 5 ampere s pe r squar e foo t (A/ft 2 ) . I ncontrast , th e interio r corne r i s no t adequatel y



### Ji.P. 4

TABL E 1 . SURFAC E ARE A O F HAR D CHROMIU

M PLATIN G TANK S A T MODER N HAR D CHROM E SERVIC E COMPAN

Y

Tan k Surfac e area , f t

1 - 2 8 2 4 2 3 4 2 4 4 4 5 2 8 6 2 6 7 1 6 00 7 2 5 8 1 9 9 1 9 1 0 1 9 1 1 6 0 1 2 3 6 1 4 5 6 2 0 2 5

a Note : Th

e solutio

nleve l i s generall y 6 inche s fro

m the blower s alon

g th e side s o f the tank . Tota l workin g volum e o f solutio

nat thi s plan t i s 18,70 0 gallons .P. 5

EXTERIORA CORNE R/

/ / INTERIOR CORNE R

CURREN T DENSIT Y=0. 5 A/ft 2

NARROW GROOV E 

### 7~7

Figur e 1 . Electrica l field s o nthre e differentl y

shape dsurfaces .

/
.P. 6

plate da t thi s curren t densit y becaus e th e attractio nbetwee nth e stee l an d th e chromiu

m i s no t stron g enoug ht o allow penetratio no f th e chromiu m int o th e recesse s o f th e corner . Likewise , chromiu m canno t penetrat e int o a narrow groov e becaus e th e stron g attactio no f th e stee l fo r th e chromiu m a t th e exterio r corner s inhibit s th e passag e o f chromium int o th e groove . T o provid e a protectiv e surfac e o ngroove do r recesse dareas . Moder nHar dChrome use s electroles s nicke l plating . Althoug hnicke l doe s no t provid e th e sam

e wea r resistanc e an dcorrosio nresistanc e a s chromium , th e absenc e o f electrica l field s allow s fo r penetratio no f th e platin g materia l Int o groove dan drecesse dareas . C . Emissio nContro l Emissio ncontrol s o neac hhar dchromiu m platin g tan k ar e similar . A n exampl e o f a typica l contro l configuratio n1 s show ni nFigur e 2 . Emission s fro

m eac htan k ar e drawnb y anInductio nfa nthroug hhood s o n tw o side s o f th e tank . Emission s ar e the nforce d throug ha simpl e impingement-typ e mis t eliminato r (collector) , locate d o nth e roof . Th e collector s wer e designe d specificall y fo r thi s facilit y

b y Mr . Nicholl' s grandfathe r 1 n1952 . Mos t o f th e unit s hav e bee nreplace d twic e sinc e then . A typica l collecto r consist s o f a nenclosure , measurin g 5 fee t (ft ) b

y 4 f t b y 4 ft , housin g mor e tha n10 0 fla t meta l strips . Adjacen t row s o f meta l strip s han g a t abou t 120°-angle s t o eac hother , creatin g a baffl e system o nwhic hth e add-bear1n g mis t Impinges . Th e cleane d ga s exit s throug hvent s o ntwo side s o f th e collector , an d th e solutio ntha t 1 s collecte ddrip s bac k Int o th e platin g bath . Th e collector s appea r t o provid e adequat e contro l o f chromiu m emissions , a s evidence db y th e absenc e o f visibl e emission s fro m th e vent s durin g th e visit . Th e actua l contro l efficiencie s o f th e collector s hav e neve r bee nmeasured , however . Th e physica l desig no f th e collector s 1 s no t suitabl e fo r measurement . Ther e ar e fe w section s o f straigh t ductwor k upstrea m o f th e collector s an d ther e ar e no stack s o nth e collectors . Mr . Nichol l note dtha t emission s canno t b e estimate d b y a mas s balance , either , becaus e extremel y accurat e scale s ar e neede d t o detec t th e fe w ounce s o f chromiu

m use dt o plat e a par t tha t weigh s 6,00 0 pounds . Mr . Nichol l note dtha t ther e ar e man y factor s affectin g emission s fro m chromiu m platin g tanks . Th e proces s itsel f i s highl y inefficient , 1

n tha t mor e energy

1 s use dt o generat e hydroge nga s tha ni s use d t o appl y chromiu m plate . Th e degre e o f visibl e mistin g increase s a s th e voltag e an damperag e throughth e electrode s increase . Th e surfac e are a o f part s being plate ddirectl y affect s emission s becaus e i t affect s th e require d current . Finally , ther e appear s t o be a correlatio nbetwee nth e freeboar d dept h(distanc e fro

m to po f solutio nt o hoo dvent ) an

d th e amoun t o f solutio ncollecte db

y th e contro l devices . Thi s ha s no t bee n substantiate db

y actua l experimentation , bu t Mr . Nichol l ha s notice d tha t increasing th e freeboar ddept hdecrease s the amoun t o f solutio ncollecte d b y the contro l devices .



### ^T(FAr U 

### -7-7-7 /

J s / 

# f 

# M

7

\ IMPINGEMEN T

MIS T ELIMINATO R / /////// /

ROO

F

CONTROLLE D MIS T RETURN S TO TAN

K



# 1- 1 r- t HAR D CHROMIU

M PLATINGTANK S S / S / / 7 /////////// / FLOO

R

Figur e 2 . Typica l contro l syste m o n a hard chromiu

m platin g tank .P. 8



### D . Conclusion s Th e sit e visi t t o the Moder nHar dChrom e Servic e Compan y plan t wa s very informative . Th e plan t doe s no t appea r t o b e a goo dcandidat e fo r sourc e testing , however . Th e captur e an dcontro l device s ar e in satisfactor y

workin g condition , bu t the - 

### configuration s ar e no t suitabl e fo r EP A Metho d5 testing .

7 .