Semi-Quantitative Spectrochemical Analysis of Zinc Concentrates for Gallium, Germanium, and Indium

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library COLORADO SCHOOL OF H IN E S GOLDEN, COLORADO

SEMI -QUANTITATIVE SPECTHOCHEMICAL MALtSIS OF ZING m m w r n m t m fob oio^iuM, gbbmanium,

ARB INDIUM

Lawrence Joeoph ChocJ&e

ProQuest Number: 10781411

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o g o*A r~* A v>

chamois* and dried on the Bietert plate drier# The Applied Be search Laboratories compare tor-densiteaeter was given a three-hour warm-up period before any readings were attempted,

The stability of the densitometer

was greatly Jj^reved by this warm-up period#

The densit­

ometer was then adjusted to read 100J& transmission on the unexposed portion of the plate directly above the 2475*3 A lithium line#

All the lines of the desired element in the

spectrum exposed were examined for possible use in the calibration curves*

The percent transmission value of

the 2475*8 A lithium line was recorded* with the transmis­ sion values of all possible lines of the desired element• Ho background corrections were made* These transmission values were then referred to the emulsion calibration curve and converted to relative intensities.

The ratios of line intensities to intensity

of the lithium line were calculated*

The ratios for each

sample were then averaged* and the average plotted versus percentage composition of the sample on two by three-cycle logarithmic graph paper*

an

Ehess plots should ho straight lines* and a partial elimination of m m m of the lines ©an he made by eaessiinabiom of the graph*

Other lines mar he later eliminated hy

interferences or suppressions, as in the ease of the interference of the 5059*1 A gerMnium line hy a very strong indium line at 5039*5 A in subsequent analysis of unknown samples*

A list of interferences is given hy

Harvey^ in conjunction with sensitivity values of the various lines of the elements. fha lines used for the condos Ition calibration curves are given in the following tablet

mme n

Sleanent Qa

Ge la

Li

Line, A

Meage* %

ms.e

0,001 «* 0*1

2689.9

0*1 *. 1*0

3124.8

0 *001 '•*' 0 *1

3269.4

0*05 ♦ 1*0

2932.6

0*001 4* 0*1

8997.0

0*1 - 1*0

8475.3

Reference

On the following pages are photographic copies of the composition calibration curves for gallium, germanium, and indium*

zz

s

o

o

T*l/»0 ‘ot»*h

H n/*0 *®W»»

0.1

o

24

3 « 44 »

1 t

8 O

1Q,Q

m

n/*i ‘m n

2S Analysis at Sandies* Seven selected samples of zinc coneexitrates and one sample of indium metal were then treated by the following procedure to determine the amount of gallium* germanium* and indium contained in the nine concentrates* and the amount of gallium and germanium in the indium metal# A tMHnilligrm sample of each of the zinc ooneen** trates were carefully weighed and mimed with 90: milligrams of lithium carbonate and thoroughly ground and mired In the mortar#

Three portion® of each sample were then charged to

the cups of three Easier electrodes# and carefully packed so that each electrode contained approximately the same quantity of sample#

the arcing# exposure* and plate

development were performed under the same conditions as outlined under the procedure for the Composition Calibre** tlon Curves*

the percentage transmission values of the

lithium line were recorded with the transmission values of the lines of germanium# gallium* and indium#

These trans*

mission values were then converted to relative intensities from the emulsion calibration curve and the ratio of line intensity to lithium carbonate intensity determined*

fhe

ratios from the three samples were then averaged* and the average ratio read directly-from the calibration curve® as percentages of elements contained in the total sample* These percentage® were then multiplied by the dilution factor of ten to obtain the percentage of the element present in the original sample. two milligram® of Indium metal was carefully filed

m

into 18 milligrams of lithium carbonate on the balance pan, ana. the entire sample was transferred to the cup of the electrode*

this quantity of ■sample nearly filled- -the cup

of the electrode#

The sample was arced in the same manner#

the plate developed, and percentage transmission mines were read*

The transmission m l ties were converted into relative

intensities, and the ratios averaged and referred to the calibration curves be determine the'quantity of gallium and germanium present in the total sample*

These percent­

age mines were then multiplied by the dilution factor of ten to obtain the percentage mine of the gallium and germanium present in the Indium metal* A tabulation of the transmission mines* ratios* and percentages found for each run on a sample is given in Table XXX on the following pages*

Table

b s >9