Ralph, let me know if any of this in new to you. Found in in an industrial toxicology textbook from 1992.
Uses of cobalt:
1) superalloys, esp. for gas turbine, incl jet engine use.
Contain up to 60% cobalt, with 15-20% Cr, Ni, and W (tungsten for those of you who went to US public schools)
Account for 35% of US use, amounted to 3.8 mil lbs in 1982.
2) Corrosion and abrasion resistant alloys, incl stainless steels:
Stellites: 60% Co, 30% Cr, lesser amounts of W and C.
Tribaloy: 50-60% Co, 30% Mo with small amounts of Cr and Si.
Used for machine tools.
Vitallium: 65% Co, 30% Cr, 5% Mo. Used for surgical and dental implants.
3: Co serves as the binder in cementing tungsten carbide and other metal carbides. The resulting wear-resistant 'hare metal' accounts for 10% of US consumption.
4: Magnet steel: 35% Co, lesser amounts of Al, Ni, Fe, W and Cr.
Soft magnets are also Co based and are used in mfr of radio and TV communications equipment.
5: Cobalt salts and compounds,
a) organic complexes used as drying agents in paints, varnishes and inks and as bonding agents between rubber and metals or textiles, for example in tires. The color change in between blue to pink of many Co salts make them useful in dessicants.
b) addition of less than 2 ppm of Co oxide to glass masks the yelllow tinge imparted by the presence of Fe oxides, larger amount leads to blue coloring in glass and ceramics.
c) Additions of up to 0.5% provide absorptive effects of welder's goggles.
d)mixtures of CoO with other oxides produce pigments ranging in color from blue, green and violet to pink and brown, while K3Co(NO2)6 based paints are yellow. Considering drying agents and paints, the paint industry consumes over 2 mil lbs/pa in the US.
e) Unfortunately for bulls on CMR, but fortunately for the health of alcoholics, CoSO4 and CoCl2 are no longer used as foam stalizers in beer (Is that where Labatt's Blue comes from?)
f) CoCl2 is added to animal feeds, fertilizer and salt licks in areas where the soil is deficient in Co.
So Ralph, what do you think? I didn't know the concentrations in the superalloys, or the volume of Co used in paints, especially drying effects and non blue pigments.
Just in case CMR wants to update their official website, and research shows you have to update at least once per week to get traffic, the reference is Hazardous Material Toxicoloby by Sullivan & Krieger, pub. Williams and Wilkins, Baltimore, 1992, p. 853-854. |
