# Last edited on 2020-02-16 13:52:56 by jstolfi

Extracting cobalt from a "cobalt coloring" agent
for pottery.

Tried extracting with acetic acid and lactic acid.

Acetic acid gave a light red liquid and left a lilac (light purple) precipitate.
Microscope inspection showed colorless(?) ground glass like particles with some larger particles with deep cobalt blue color.

Lactic acid gave a very light pink liquid and a swollen purplish pink ppt mass, more than twice the
original pigment volume.  Microscope showed some larger ground glass like particles with deep cobalt blue color, as with acetic acid; but also a large number of transparent crystals in the form stubby needles, slightly pink. 

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2018-09-14 

Thermocouple readings during heating are in heating-2018-09-14.txt

  gnuplot << '  EOF'
  set term x11
  plot "heating-2018-09-14.txt" using 7:11 with linespoints
  pause 300
  EOF