T-

COPY AD-A221 135AD

NEHOAANDUH REPOAT ARCCB.MN.gOO I O

DETERMINATION OF SOD'UM CYAN/,DE IN COPPER

AND CADMIUM CYANIDE PLATING SOLUTIOA'S

BY PRECIPITATION.FORMATION TITRATION

SAMUEL SOPOK

,IARCH '990

US TRilY ARIilIiIETT RESEARCII,

DETEIOPiIEIIT AIIII EII EI II EERI 1I C C EIITERCLOSE COMBAS ABUAUENTS CENTEB

BENÉT TABOBáIOBIE§wt[EnvLIET, N.Y. 12189-{060

APPROVED tOR PUBLIC RELEASE; DISIRIBUIIOX UNIIMITED

DTIC

§,ff0

I 05 o" 04lf

II

OISCIAIMER

Thc findings in this repozi arc not to be coastrucd as ü 6ffi¡f,¡rDcPartncnt of thc tuny position r¡rlcss so dcsiErated by othcr ar¡cbtlddocrr¡cnts.

Tlrc usc of trade nanc(s) ard/or n¡nufacturcr(s) docs not conscitute

an official indorsenent or approval

DESTRUCTIGi NOTIG

For classificd docuncnts, follow the procedu¡es in DoD s2oo.22-t¿1,

Industrial sccurity Manual, section II-lg or I}oD s2oo.l-R, Info:rationSecurity Progran Regulation, Chaptcr IX.

For tnclassificd, linitcd docunents, destroy by a¡ry nethod thst willPrevent discl0su¡e of contents or rGconstruction of thc docunent.

For r.¡nclassified, tmliuited docr¡nents, dcstroy rhen the rcpo¡t isno longer ncedcd. Do not lcturn it to thc originator.

stcñeponr oocutlENTATloN rlGE

ARCCB-¡a-900I0 ;=ñ; REFoRT ¡ PERloo covEtÉoa. flf LE (rd Su¡tlt¡')

DETERMINAÍION OF SODIIJM CYA¡{IDE TN COPPER

AND CADMIIJ}'! CYA}¡IDE PIATING SOLUTIONS BY

PRECIP ITATION-FORMATION TTTRATION¡ErG ,ffiñé.nEPonr truraen

A!,lCt,lS No. 6126. 23. 1BL0.OAP'PRON No. I¡.O2ZRAENI'LSC

iññEIx¿rttox xa¡E

U.S. A¡rnY A3DEC

Benet laloratories, SMCAR-CCB-TL

wateti\rliet, NY 12189-405 12. REPORf OATE

March l99Offi^Ho^oonEssU.S. Arff,Y ARDEC

Close Conbat Armaments Center

UNCLA.SSIFIED

Approved for public release' olst'ribution unlÍtrriEed'

20' tl dttl'?at laa

@oc¡nGD")

Che¡nical AnalYsisSodiLún CYanideCopper Cyanide

Plating SolutionsCad¡nium CYanide PlatinqPreciPitat ion-Formation

SolutionsTitration

ffirrtrDlocliú'at.I;l:T.ff; il"r..*" lacks an acceptable analvtical merhod ro adequarelv

detennine and monitor sodium cva'¿aá-li coPper ád cadmirm-::::t:i*:tl:::::ffiH i:"J:";;:i"n"ni""';;;:- ii'r'i",'"r::: -1"^:':il:':,T:'l:ui:presented providing "."ápi"¡r"

.rr"ry=i" .r,a *"it"ring of this salt in these

plating nrocess.-.s.' *: épti¡n* o'.r"iir,i--t*g""-of sáalu¡n cyanide are 58 g'l1

maxi.mum in copper .r.r,iuá'n,;;i"; ="i:il;":I?- 1:-n1:-'.?:tTH :1"::T.,*§]}lH ;1.;::;':";íil;:.'^il."l"lii.1ns preclsiel: 1:" in rhe ranse of

. ÍCONTID ON RE:VERSE)

DOtoL

t ,at rl rm Éor?¡o¡ o, t tloY aS 13 o.l¡o|.Etc

¡¡c¡?ror or'l'rat¡ rlcgfD- D-.

ABSTIACT (COT.D)

'0.5 to 4.O g/L, prowiding adequate monitoringsolutions sr4{pr:ted by six years of testing.

of these metal finishine

[,NCI.ASSIFIED¡aCUtttV CLA3¡tFtCAftOX OF fXt3 ,AOClrñrñ D... ¿a..?.¿)

TAELE OF COIITEI{TS

Eese

ACKNOI{LEDGEMENTS i i

I¡¿TROOUCTION.... 1

EXPERIHENTAL PROCEDURE ... 1

RESULTS ANO OISCUSSION . 2

REF EREI{cES Á

TABLES

:, EXPERIHENTAL TITRATION CATA FOR THE SODIUM CYANIDE STANDARDSOLUTION

:I. IXPERII'IENTAL fITRATION OAÍA FOR SOOIUM CYANIDE IN COPPERCYANIDE SAMPLE SOLUTIONS

III. EXPERII,IENTAL fITRATION DATA FOR SO0IUtl CYANIDE IN CAOMIUMCYA}.IIDE SATPLE SOLUTIONS

:V. PRECISION 0F A 2-ml CLASS-A PIPET

v. PRECISION OF 5O-g/1 SOotUr{ CyANtO€

VL PRECISION OF 11-9/1 SILVER NITRATE

VII. PRECISION OF A sO-m.I CLASS-A EURET

STANOARO SOLUTION

TITRANT SOLUTION

NTIS GFA&IDTI,C IÁBU¡annou¡¡ced

i Justtflr¡aLl

6

6

7

un

I

,-- frvalr ;Ed/oiDlst I Speotet

in,t I Iidi-_t_

ACTilOXLEDGE!,IET{TS

Specia) thariks are given to E'l]en Fogarty and Rose Neifeld of Benet

;aboratories for their rssDective word processing and technical editing work on

th'is nanuscriot.

11

^l

IT{TROOUCTIOtr

The chemical Iiteratune Iacks an acceptab'le analytical method to deternine

and monitor sodium cyanide in copper and cadmium cyan'ide plat'ing solutions in

the plating processes. Lack of optim'ization of these plating solutions causes

serious problems for the me'ral finishing industry sueh as poor quality products

and wasted resources.

The only common chemica'l analysis method to determine sod'ium cyanide in

these solutions is a co] or comparison test kit such as the one Drovided by l¡lerck

Corporation (ref 1), however, th'i s method provides poor precis.ions.

The specific method described in this report provides acceptab'le analysis

and mon'i toring of this salt in the meta.l f inish'i ng processes. The method con-

sists or a precipitatioil-tormation ritration (refs 2,3). Re'lative precisions of

this method are in the raige of 2 to 3 peneent.

EXPERIIIEnIAL PROCEOURE

Strict analytical chemistry methods and procedures are foi'lowed throughout

thls exoerimental orocedure sect.ion. An excellent source of reference for these

rethods and orocedures is by Fritz and Schenk (ref 3).

Two analytical reagent grade standard solutions are required. The first rs

a 50 + 0.S-gt '1 sodium cyanide solution (l g/1 sodium hydroxide for stabil ira-

tion), and the second is a 1? 1 0.1-gll si lver nitrate t,i trant so.l ution. These

:,{o solut'ions are prepared and standardized as described'in References 2 and 3.

Two orher analytical reagents are required. The first is potassium iodide

indicator powder and the second is concentrated ammoni,¡m hydrox.ide solution.

The procedure to prepare standard and sample solutions is the same for the

copper anc, cadmium cyanide solutions. This titration analysis requ.ires that a

mi'l 'l i'l iters (ml ) of sanpie or standard solution i.s pipetted into a 400-mi

S

beaker. Then the beaker is fil]ed to about the 100-ml mark with deionized v{ater

and a stirring bar is added. Also added to this beaker is 0.1 gram of potassium

iodtde'indicator anc! 5 nl of concentrated ammoniun hydroxide solution.

The solution is titrated using the si'lver nitrate titrant to a fa'int ye11ow

turoid pernanent endpo'int, recording the amount of titrant dispensed in millili-

ters at the endgoint.

All standard and samole solutions are analyzed in triplicate. Sod'ium

cyan'ide concentrations in the samo'les are calcul ated by normal chemical

stoiciliometry.

RESULTS ANO OISCUSSIOI{

Exoerimenta'l standard titration data are presented in Table I for these

solutions. Experimenta'l sample titration data are presented in Table II for

copper cyanide sample so] ut'i ons one and two and in Table III for cadmium cyanide

sample solutions three and four. The titration can be summarized using the

fo!lowing equations. The f irst tvro involve the cyanide-si'l ver ion relationsh'io

ano the th'i rd involves the iod'ioe-si lver ion endpoint indicator re'l ationship:

Ag* * 2CN- <--> (Ag(CN)e)-

(Ag(CN)2)- + Ag+ <--> 2A9CN

Ag+ * I- <--> AgI

(1)

\¿)

(3)

Sriver cyan'icle vúil'l not precipitate in these solutions due to the presence of

ammonium ions allowing on'ly the silver iodide to precipitate at the endpoint.

The calcu'lat'ion for determining the concentration of sodium cyanide in the

original sample so'l utions is

g/'l NaCN = (50)(All(B) (¿)

1

where

A=n'l of

= m] of

titrant for samole

titrant for standard

is the combined result of many constants

B

iwhere the constant va'l ue

( refs 2,3 ) .

n Eq. (4 )

Using Eq. (4), -he respective sodium cyan'ide values for ccpper cyanide

samo'le solutions one and two in Table II are 35.1 and 49.9 g/1. Lirewise, rrs¡no

ihe same equation, the resoect'ive sodium cyanide vaiues for cadmium cyanidc

samo]e solutions three and foulin fable III are 84.9 and 140.1 gz1.

!t is useful to evaluate the variations in prec'ision for the materials and

rerhods ,lsed. Taoles IV through VII present the data for the 2-m'! c lass-A

oioets, 50-g; ! sod-¡um cyanide stanctard solution, 17-g/1 silver nitrate titrañt

sojution, and the 50-ml class-A burets, respective'ly.

The data obtained by this riethocl are sufficient to aclequately monitor the

sodiun cyanide'i n the meta'l finishing processes, thus prov'iding efficient use of

resources. fhe opt'imum operating ranges of sodium cyan'ide are 58 q,l max:rnr¡m :n

the coooer cyanide platrng solr¡tions and 149 gr'1 maximum in the caomium.:yan.:r)

oirting onl*.¡iions. Íhe nesu'l t'ing precisions are in the range of 0.5 rc t.0 § :.

orovioing adequate monitoring of these metal finishing solutions suoporteo bv

srx years of testing.

,a

t.

2.

REFEREIICES

"EM Quant Chlorine and Cyanide fests," El¡t Science Civision of Herck

Corooration, Cherry H'i l l, NJ, 1980.

0. Peters, J. Hayes. and G. HieftJe, themiqal separatio-!_q_a!q.Measure-rne¡ts:

Theorv and Prqglice of Analytical Chemistrv, W. B. Saunders Company

3.

ohl laclelphia, PA, |9?4.

i. Fritz and G. Schenk,

A1 lyn and Bacon. Inc.,

q@cal Chen.istrv, Fif th Ectitron.

Boston, l,tA, 198? .

_^

TAELE I. EXPERI}TENTAL TITRATIOÍI DATA FOR THESOOIUI{ CYATIIOE STA}TOARO SOLUTIOil

Rep I icates

1

2

3

¡((avgl

Titrant Used (ml)

10. 2s

10. 20

10.20

t0.22 r_t

TABLE II. EXPERII{EilTAL TITRATIOII DATA FOR

CYAilIOE It{ COPPER CYA}¡IOE SAI'{PLESOOIUil

SOLUfIONS

i Sample OneI - i '-¡nt Jsed (ml I

-----t---l

Sample TwoIitrant Used (ml I

, :<

?. i5

7 .20

?.1?

10. 20

10. 20

10. 20

10.20

?eO; rCareS

:

?

3

x(avg)

TAELE III.

----fI

I

I

iI

EXPERII{ENTAL TITRATIOT{ DAÍA FOR SOOIU}ICYAi|IDE I¡l CAOl,lIUl,l CYAiIIDE SAI'IPLE S0LUTIOI{S

--T--Samg le 'hree I Samole For¡r

' _ :::_:':11.'''' __L__""1: :'"0 '*''i?.35

1?.35

1?.35

1?.35

28. 60

28,65

28. 65

28. 63

ÍAELE IV. PRECISIOT¡ OF A 2-MI CLASS.A PIPET

I Rep l icatei

:

2

3

J

5

6

x(avg)

Sn

1

2

3

I

5

6

X(avg)

Sn

*Sodi ur¡ cyanide concentrat.ionsgiven in References 2 and 3.

49. 9?

49. 99

¿9.99

50.01

50.00

50.02

50.00

a,o2

are :alculated.by methods

2-ml Pipetvolume (ml)*

2 .00

2.01

i .99

1 .99

1 .99

2 .01

2 .00

0.01

rvoiumes are ca lcu'! ated f rom the *eignt-vo.l ume re,l ation_shio -f a croetted deionlzed ¡¡ater so'l ution corrected fortemoerature.

fAELE V. PRECISIO}I OF A 5O.g/.I soolu¡t CYA}IIOE STAN0ARO soLUTIoI{

I

Reo l i cate Sodium Cyanide (OZt¡*

TABLE /I. PRECISIOT{ C2 A 77.9/ I SILVER I{ITRATE T¡TRANT SOLUTIOT{

Repl icate Si'lver N'i trat

I

2

2

4

5

6

(avg)

Sn

1?.1

1? .0

t7 .2

16.8

16. 9

16.8

17.0

o.2

X

__J*Srlver nrtrate conceñtrations are ca¡culated by methodsEiven in References 2 and 3.

TABLE VII. PRECISION OF A sO.mI CLASS.A BURET

Rep I : cate Volume 1¡1 ¡*

'I

2

3

4

5

6

x(avg)

Sn

24.9A

2¿ .98

25.02

25.05

24.98

25. 05

25.00

0.0¿

*Volumes are calculated from the Height-volume relation-ship of a contained deionized ,rater solution correctedÉor temperature at a point one-half ful'l --25 rnt.

TECHI{ICAL REPORT INTERNAL OISTRIBUTION LIST

r{o. cFCOPIES

CHIEF, OEVELOPI,IENf ENG¡I.IEERING OIVISIONAÍTN: SIICAR-CC8-D

-DA-DC-0t!-0P-DR-0S (SYSfEtlS)

CHIEF, EI,IGINEERING SUPPORT 0IVISIONATTN: SIICAR-CCB-S

-sE

CHIEF, RESEARCH OIVISIONATTN: SI,ICAR.CCB.R

-RA-RH.RP

-RT

TECHNICAL LIERARYATTI{: SilCAR-CCB-TL

TECHNICAL PUBLICAfIONS & EDITING SECTIONATTi{: StlCAR-CCB-TL

OIRECTOR, OPERATIONS DIRECTORATEATTN: SttCt{V-0O

DIRECTCR, PROCUREI.IENT OIRECTORATEATTN: SilCWV-PP

OIRECTOR. PROOUCT ASSURAT¡CE DIRECTORATEAf fN: SliCiaV-QA

NOÍE: PLEASE t¡OTIFy 0IRECTOR,At{Y ADORESS CHANGES.

6€¡lET LABORATORIES, ATTN: SHCAR-CCB-TL, OF

1

1

I1

1

1

1

2

1

1

II

5

W

IECHN¡CAL REPORT EXTERNAL OISTRIBUTION LIST

¡¡0. 0FCOPIES

NO. OF

CCP I ES

ASST SEC OF THE ARMYRESEARCH ANO OEVELOPiIENTATTN: 0EPT FOR SCi ANO IECHTI{E PENTAGON

|{ASHINGToN, 0.c. 20310_0103

AOI¡{ It{I STRATOROEFENSE TECHIi¡ICAL INFO CENTERATTN: DTiC-FOACCAI¡TERON SfAfIONALEXANORIA, VA 22304-5145

COüMANOERUS ARI,IY AROECATIN: Sl,lCAR-AEE

St¡tCAR-AES, BLOG. 321SMCAR-AEf-0, BLDG. 351NSHCAR-CC

.SMCAR-CCP-ASIICAR-FSAst'tcAR-FSlr- E

SMCAR.FSS-0, 8LOG. 94STCAR-I}II-I (STINFO} BLDG. 59

PICATINNY ARSENAL, NJ 0?805-5OOO

O I RE CTOR

u§ ARl,lY EALrISf IC RESEARCH LABORAToRYATrN: SLCBR-00-T, BLDG. 3OsAEEROEEN PROVING GROUND, MD 21005-5066

O I RECfOR

COIfiANDERROCK ISLANO ARSENAL

I ATTN: SIIICRI-ENH lROCK ISLA¡|o, IL 61299_5ooo

OIRECTORUS ARI{Y INOUSTRIAL EASE ENGR ACTVATTN: AHXIB-p 112 RocK ISLAI{o, IL 61299_?260

C0f.lt'!AN0ERUS ARI{Y TANX-AUT! V R&D COiltt{ANOATTN: AIISTA-00I (TECH LIB) ¡[{ARREN, }t¡ 4839?_5000

COÍ.TMANDER

US Í.IILITARY AcAoEI,tY 1ATTN: OEPART¡IENT OF MECHANIcS[{EST POINT, NY 10996-1?92

US ARI{Y I,IISSILE COI,IMANOREDSTONE SCIENTIFIC INFO CTR 2ATTN: 0OCUMENTS SECT, 8LDG. 4484REDSÍONE ARSENAL, AL 35898-5241

COI,IiIANDERUS ARMY FGN SCIENCE ANO TECH CTR

I ATTN: DRXST-SO I220 lf]1. SÍREET, N.E.

US ARI¡IY I{AÍERIEL SYSTEilS A}IALYSIS ACTVATTN: AI.IXSY.IIPABEROEEN PROVING GROUNO, HO 21005-50?1

COI'I,TANDER

HQ, AHCCo¡.!ATTN: AíSMC-iMP-LROCI( ISLAi¡o, IL 61299_6000

CHARLOTTESVILLE, VA 2290i

cot-,tr{AN0ER

US ARIIY LAECOI.IMATERIATS TECHNOLOGY LABATTN: SLCttT-IlrL (TECH LIB)I{ATERTOI{N, üA 021?2_OOO1

NorE: PLEASE l"lorlFY cof'lf{AiloER, ARI{A]IENT_RESEARCH, 0EVELoP|{ENT, ANo ENGINEERINGCE}¡TER, US ARI,IY AI{CCOM, ATTN: BEI{ET U$OñAiOñiiéI SUCIR-CCB.TL,I{ATERVLIET, t{y 12189-¡1050, OF At{y ADDRESS CHA¡.GES.

TECHNICAL REPORT EXTERNAL OISTRIBUTIOI¡ LIST (COI{T'D)

¡¡0. 0FcoPrE

NO. OFq0P¿E§

1

col'll{At{0ERUS ARMY LASCO}I, ISAATTN: SLCIS.IM.TL 1

28OO POWDER t,IILL ROAO

AoELPHI, M0 20?83-1145

cor'li,tAN0ERUS ARIIY RESEARCH OFFICEATfN: CHIEF, IPOP.0. Box 12211RESEARCH TRIANGLE PARK. NC 21'I09-2271

3 I RECTOR

US NAVAL RESEARCH LA8ATTN: MATERIALS SCI & TECH OIVISION

c00E 26-2? (DoC LIB)I{ASHINGToN, 0. C. 203?5

C0Ml,lAN3!RAIR FORCe ARMA}IENT LABORAÍORYATft{: AFAÍ L/}lt{EGLIN AFB, FI 32512.5437

CO¡{I,IANDER

AIR FORCE AR¡1AMENT LAEORATORYATTN: AFATL/MNFEGLIN AFB, ;L 32542-343A

METALS AND CERAI.TICS INFO CTR

EATfELLE COLUMBUS DIViSION505 XING AVENUE

coLutrBus, 0H 43201-2693

NOÍE: PLEASE NOfIFY COtll,lANOER, ARl,tAl,lENT RESEARCH, OEVEI0Pi'iENT, AND ENG¡NEERIt{GCEi¡TER, US ARI{Y A}lCC0ii, ATTN¡ BE}'IET LAEoRATORIES, S!¡ICAR-CCB-TL,

IIATERVLIET, NY 12189-4050, OF AT{Y AOORESS CHAT{GES.