The analysis
of inorganic
spectrophotometry Part
V. The
analysis
siliceous
materials
and the hydrofluoric
by atomic
absorption
acid decomposition
technique.
of ferrosilicon
T11c: procluction of ferrosilicon is normdly controllccl by determining tile content of silicwn, aluiiiinium, calcium nnd l~liosplioriis: in ncidition, it is of importance to know tlw concxntration of a number of Ininor ant1 tract metals. Tile present scllcn1e
contains n1etiiocls for tl1c tietern1ination of silicon, niuminiun1, magncsiun~, calcium, lead ancl tin. It is highly titanium, i11angancsc, cliron1ium, copper, nickel, cohlt, probable tl1a.t tl1c principles of the prcscnt sclicme, wit11 proper riioclific~~tions, \vould lx applicable to tl1e analysis of otlkcr ferrous ;~lloys. Sniiiplcs of ferrosilicon arc (tlcscrilwcl in Pnrt I of this s;cricsl).
attacked
wcortiing
to
tlccoiiil”‘sitioll
nwtlioti
2
Analytical results for fcrrosilicon arc usually reportecl, not as asides, but as clcmcnts. Koutinc analyses of tllis mntcrinl arc tl1crcfore conveniently ninde with a special series of primary standards (dcsignatccl 1x10~ as metal stnndnrci I), Tlic corn--Ï lxAtir)n of the secondary stanclarcl solutions is also given below. Eacli of tl1csc scrics of stanriarcls is designed for nicnsurement of a dcfinitc clilution of tlic s:ui1pie solution ; tl1is tiilution is intiicatcd in each case. Silicorc. Wcij$i 0.1070 g of silicon diositie and preparc silicon stanclarcl I (0.5 mg Si/ml) as clescribccl in Part I. Transfer 9-37 ml, in steps of r ml, of tllis solution to plastic bottles and atlci water to a volume of TOOml. If the sample solutions are clilutcd I0 times, the series covers tluz range 22,5-92.5:4 Si, in steps of 2.sfl/“. Ahimi7~~~1~7rr.Weigh x.0000 g of tile nictal and prepare aluminium standard I (x mg Al/ml) as dcscribcci in Part I. Dilute standard I with water to give a concentration of 0.2 lng _4l/ml. Transfer up to 30 1111,in steps of 2.5 ml, of this solution to plastic bottles, add 50 ml of saturated boric acicl solution, 5 nil of liydrofluoric acicl, and water to a final volun1c of 100 ml. If tllc saml~lc solutions are iincliluted, tlic series covers tl1c ranKe up to 3OA, Al, in steps of 0.2504,. Mq7usirrsw. Weigl1 o.xGgS g of magnesium osicle ant1 prcparc magnesium standard I (0.1 mg Mg/ml) as described in Part I. Dilute standard I wit11 water to a concentration of 0.005 ing Mg/ml. Transfer up to 20 ml, in steps of 2 nil, of this solution to x00-ml volumetric flasks and dilute to volume with water. If tlie saniple solutions are undiluted, the series covers the range up to o.os~/~ Mg, in steps of o.oo~~/~. Cnlci.1~2. Weigh 0.2497 6 of calcium carbonate and preparc calcium stanclarcl I as described in Part I. Dilute standard I with water to give a solution containing 0.01 mg Ca/ml. Transfer up to 40 ml, in steps of 5 n11, of this solution to roe-ml volumetric flasks, acid xoo ml of potassium reagent solution (IO n1g K/ml) and dilute to tl1e mark with water. If tile sample solutions are diluted IO times, the series covers the range up to 2% Ca, in steps of 0.257/o. ?‘z’tnlzi?l?rt. Weigl1 x.oooo g of the metal and prepare standard I as described in Part I. Dilute standarcl I with water to a concentration of 0.1 mg Ti/ml. Transfer up add 50 ml of boric acid to 20 nil, in steps of 2 ml, of this solution to plastic bottles, solution, 5 ml of hydrofluoric acid and a volume of aluminium standard solution
I.25 I.11
I.24
75.8
75.5
75.8
8 Wot reported.
1.2j
la
1.6
0.21
Rel . dev.
76.0
4.9
0.03
0.16
Stand. dev.
Certificate value
0.001
I .2q
0.013
0.013
0.50
3.6
0.02
O._jG
0.54
0-57
O.jG
O.j7
O-59
-a
II
0.010
O.OSj
0.078
0.094 0.093
0.090
0.071
STAXDARDS SAMPLE SO. 30j
0.013 0.013
0.012 0.012
75.7
Averages
1.26 I .‘J
57
759
AXALYTICAL DATA FOR THE BRITISH CHEMC.tL
g
I
TABLE
g
Ln
c
_a
1.G
0.002
0.12s
0.127
0.IZf.i
0.128
0.131 0.1 ?g
-II
2.7
0.0026
O.Ogj
O.Ogj
O.Ogj
0.097
O.Cgj
0.090
(FERROSILICOS)
0.10
3-o
0.003
_a
1.6
0.0013
-*
-a
2.1
0.004
O.ISj
o.o;g 0.100
o.o;g
0.192
O.Cgi
below about o.olyO co O.OSl
0.1.34 O.lSG
O.IS4
0.1sg
o.cgs
Brlow detection limit, i.e. 0.079
o.oso
0.07s
0.100
0.104
0.102
-a
‘4
0.0026
0.01s
0.016
0.020 0.014
0.019
0.020
SHORT
COM~IUSICA1‘IOSS
175
corresponding approximately to the amount of aluminium present in the sample solution; finally, add water to a volume of 100 ml. If the saml>le solutions are undiluted, the series covers tile range up to x .oy{, ‘I’i, in steps of o.I%,. Manga~mxa. Weigh x .oooo g of tllc metal and prepare standard I as described in f’a;t I. Dilute standard I witli water to give a solution containing 0.0x nig ivln/inl. Transfer up to 60 ml, in steps of IO ml, of tllis solution to roo-ml volumetric flasks and dilute tq volunie with water. If sample solutions arc undiluted, tlic series covers tile range up to 0.3% Mn, in steps of 0.05($. C/rrorhzc?~l. \Vcigh 1.0000 g of tllc In&al and prepare standard I LLSclescrilxxl in I’art I. Dilute standard I with water to a concentration of 0.01 mg C~/inl. Transfer up to 80 ml, in steps of x0 ml, of this solution to Ic.xbinl volumetric flasks and make up to volume with water. If sample solutions are undiluted, tllc series covers tlic range up to o.~+y/oCr, in steps of 0.0 j"/". CofiFcr. Prepare copper standard I by dissolving 1.00oo g of tllc metal in a mixture of 50 &- 5 ml of water and ao& I ml of nitric acid; transfer tllc solution to a I-1 volumetric flask and dilute to volume witll water. Dilute standard L with water to a concentration of 0.01 ing Cu/rnl. Tt-ansfci- up to 80 ml, in steps of 5 nil. of this solution to xoo-nil volumetric flasks and iiiakc up to tlic inark with water. \\‘lien mcasurccl against undiluted sample solutions, the scrics covers tlic range up t.l? o.d(;{, Cu, in steps of 0.025’~~. Nic/wI. Preparc nickel standard I as dcscril~ed for copper. Dilute nickel standart1 I wit.11 water to give a solution containing 0.01 mg Ni/inl. Transfer up to So ml, in steps of 10 ml, to roe-ml volumetric flasks and dilute to volume with water. If tlic sample solutions are uncliluted, tile series covers tlic range up to o.4o/0 Ni, in steps ol 0.057;. Cobnll. Prepare cobalt standard I as &scribed alx~vc for the preparation of copper standard I. Dilute cobalt standard I witlL water to a concentration of 0.02 mg Co/ml. Transfer up to 50 ml, in steps of 5 ml, of tliis solution to roe-nil volumetric flasks and dilute to tlie mark witli water. \Vitli undiluted sample solutions, the scrics covers the range up to 0.5% Co, in steps of 0.05%. Lead. Weigh 2.0000 g of lead (purity not less tlian 99.9%) ancl transfer to a bf2iLlttX. Add 50 + x0 ml of water and 25 + 1 ml of nitric acid, cove;’ the beaker and heat the solution until tile metal has clissolvecl. Transfer the cooled solution to a r-l volumetric flask and dilute to volume with water. Dilute this solution with watci’ to a conccntration of 0.0x ing Pb/ml. ‘I’raiisfei up to 20 ml, in steps of 2 ml, of the diluted solution to IOO-ml volumetric flasks and dilute to volume with water. With undiluted sample solutions, the series covers tlie range up to o.xo/o I+, in steps of 0.010/o. Tin. Weigh I.OOOO g of the metal (purity 99.9%, or lxttey) and transfer to a beaker. Add 500+20 ml of water, roof 5 ml of hydrochloric acid and 2.0+0.2 ml of nitric acid, and proceed as described for the preparation of lead standard I. Dilute tin standard I with water to give a solution containing 0.x mg Sn/ml. Transfer up to 20 ml, in steps of 5 ml, of tlris solution to IOO-ml volumetric flasks and dilute to volume with water. With undiluted sample solutions, the series covers the range up to I ‘): Sn, in steps of 0.25%.
Transfer
0.2000 g of tile sample
to tile decomposition
vessel,
and add by pipette
5 ml of water and 5 ml of hyc!rofluoric acid. Cover the vcsscl and let it stand at room nitric acid, close temperature for some minutes. Acid by pipette 1 ml of concentrated tllc vcsscl witllout clclay and decompose by mctllocl 3 as described in Part Il. It is recommended to attack samples of ferrosilicon by heating for 30 min at I 10~. titanium, manganese, chromium, copper, Determine aluminium, magnesium, nickel, cobalt, lead and tin in tllc main solution. Ihtermine silicon in a solution prcparcd by diluting tllc main solution 10 times with water. Determine calcium on the solution obtainccl by pipetting xc) nil of tllc main solution into a Ioo-ml volumetric flask, adding 10 ml of potassium reagent solution (10 mg K/ml) and diluting to volume wit11 water. Detcrminc silicon, nlutniniunl, nmgncsiunl, cnlciunl, titanium and clu-omium wit11 acctylcne-nitrous oxicle flames, and tllc. other elements with tllc acetylencAi flames”. Measure and calculate the results as clescribed in Part I.
The sclicmc was tcstecl by analyaing tllc 13ritisli Clicmical Stanclmds sample Tile analytical results and the ccrtificatc values are shown in No. 305 (ferrosilicon). Table I. Tile autllors gratefully acknowlcdgc for Scientific and Industrial Rcscarcll.
L
2
1:. J, ~,ANGhIYIfli I,. CAI~AC~~O-D~LGADO
(Received
October
AND I’. 1;. l'hUS, AND
D.
C.
21 Id.
~TANNING,
grants from tllc Koyal
Chilib. rich, ‘1.3 (Lc)bH) 397. SpecftvcJriru. .-Ida, 22 (IgGG)
Norwegian
Council
rfjos.
Gth, xg6S)
* According to tlic litcraturc”, not found to bc csscntial.
it is bcttcr to tlctcrminc tin with hyclrogcn-air
The analysis of inorganic siliceous spectrophotometry and the hydrof Part VI. The analysis of felspars
Ilamcs, but this was
materials by atomic absorption luoric acid decomposition technique.
The felspars and some related materials, e.g. neplieline syenite, are of great importance to tlic ceramic, glass and other industries. Routine analyses of these materials are normally concentrated upon determining iron and the alkalis. Previous have described the determinations of iron, magnesium, calcium, soclipublicationsl’” urn, potassium and minor components in felspars. The present scheme describes