Field 1
Cobalt is a very significant and valuable element. While it is mainly known for its blue
color and its magnetic qualities, it is of more worth to society. Without it people and animals
would lack vital nutrients. Yet there are also many precautions necessary when being around
cobalt. When cobalt is a part of a compound, such as with tin, calcium, or nickel, there are
processes that can separate it from them. Cobalt should be valued as it is fundamental to
recognize the importance of all elements because of the impact they have on life.
The name “cobalt” was first utilized in the 15th century deriving from the German word
“Kobald” which means “goblin” or “evil spirit”. Miners first used this name for a detrimental
mineral that gave off arsenic trioxide (As4 O6). It then became known that this occurred in the
element cobalt. Cobalt was first discovered in 1735 by a Swedish chemist named Georg Brandt.
Compounds of cobalt have been used as early as 1400 B.C. to dye glasses and glazes blue. By
observing a dark blue pigment that was discovered in copper ore, Brandt proved that it contained
a new element which became known as cobalt. Cobalt had always been used as people obtained
it from the earth to color with its vivid blue tint. Previously copper and cobalt compounds were
easily disarrayed, so Brandt had to prove to together chemists that the cobalt mineral had a much
deeper blue than the copper compounds. Finally all of Brandt’s research paid off as he was
acknowledged for his uncovering of a new element. The symbol for cobalt is Co and its atomic
number is 27. The true atomic mass is 58.9332 amu. Cobalt is a transition metal and its family is
Group nine (VIII B). Cobalt looks like iron and nickel. It is a gray, hard metal. It is ductile
(capable of being drawn into thin wires), but not always malleable (capable of being hammered
into thin sheets). Cobalt is probably most known for being a natural magnetic metal, along with
iron and nickel. Cobalt’s magnetic characteristics are easily seen in alloys which are made by at
least two metals being melted or mixed. These mixture’s characteristics are not the same as that
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of just a metal. Cobalt’s melting point is 1,493˚C (2,719˚F). Its boiling point is approximately
3,100˚C (5,600˚F). Cobalt’s density is 8.9 grams per cubic centimeter (Newton).
Cobalt has copious uses and occurrences. It is generally used to color glass blue and for
forming highly magnetic alloys (Smith). It helps steel with its resistance to corrosion. It forms
stellite, and alloy, when mixed with tungsten and copper. That metal is very valuable in drilling
and cutting because of it being able to remain hard at high temperatures. Around 25% of cobalt
makes alcino along with aluminum and nickel. This alloy is a very powerful magnetic substance
that makes industrial magnets. Cobalt is vital for human nutrition that prevents pernicious
anemia (when the blood is reduced of the necessary amount of red cells that carry oxygen).
Around 65% of cobalt is used for making alloys or superalloys (used when metals are under
extreme stress at high temperatures) (Stwertka).
Cobalt is naturally found in its chemically combined form. It is hard, gray, and magnetic.
Cobalt is fairly abundant. It is in the top third based on its abundance in the earth’s crust. It is
approximately ten to thirty parts per million. The formation of coloring materials is used by
cobalt compounds. Some examples are cobalt oxide (Co2 O3), cobalt potassium nitrite (CoK3
(NO2)6), cobalt aluminate (Co (AlO2) 2), and cobalt ammonium phosphate (CoNH4PO4). Cobalt
compounds are also known to be used as catalysts (speeds up or slows down chemical reactions).
An example is cobalt molybdate (CoMoO4) produces gasoline from crude oil. It also separates
sulfur from crude oil. The naturally occurring cobalt can be inserted into a nuclear reactor which
exposes it to many neutrons. This allows it to become cobalt-60 which is a very radioactive
isotope that puts out gamma rays. These rays are very much like X-rays and they are used for
sterilizing food and the treatment of some cancers. This isotope is extremely easy to transport so
it is valuable for field functions. It also lasts for a long time as a result of its half-life being 5.2
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years. These compounds benefit around 25% of the cobalt that the United States uses. Cobalt is
densely used in the United States, yet it is not mined here. Zambia, Canada, Russia, Australia,
Zaire, and Cuba are main suppliers of cobalt (Newton).
The atomic structure of cobalt has four energy levels. The first level has two electrons,
the second has eight, the third has fifteen, and the fourth has two. See appendix A for diagram.
Cobalt contains 27 protons and its normal form has 32 neutrons (Yinon). The filling order is 1s2
2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p5 (Electron). The electron configuration is [Ar]4s23d7
(Cobalt-Co). The oxidation states of cobalt are +2 and 3 (Elements – Cobalt (Co)). The
minimum oxidation number is -1, the maximum oxidation number is +5, the common minimum
oxidation number is 0, and the common maximum oxidation number is +3 (Cobalt-Co). The only
naturally occurring isotope of cobalt is cobalt-59. Cobalt-60 is the most common radioactive
isotope. Cobalt alone is not radioactive. There are ten radioactive isotopes of cobalt known. See
appendix B for list of isotopes. The extraction of cobalt is accomplished
by heating its ores to produce cobalt oxide (Co2O3). That compound is then heated with
aluminum to free the pure metal: 2Al + Co2O3  Al2O3 + 2Co. Cobalt oxide can be
converted to cobalt chloride (CoCl3). An electric current is then passed through molten
(melted) cobalt chloride to obtain the free element: 2CoCl3 –electric current 2Co + 3Cl2
(Newton).
Cobalt is very helpful in the industry. As previously stated, it forms stellite which is used in
high-speed drills and cutting instruments. Alcino also produces industrial magnets. Cobalt also
has many effects on health which are both positive and negative. Cobalt is used to make enzymes
(catalyst in a living organism) in animals. These are necessary for cells to function. Cobalt is a
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trace mineral for the human body and not having it can lead to problems. Cobalt is essential for
the production of vitamin B12 which produces enough red blood cells. Cobalt is also necessary in
the soil. Although cobalt is helpful, too much can cause problems. Inhaling it can cause
vomiting, diarrhea, or breathing problems. It can form rashes and irritation on the skin. It is
known that cobalt is also used for its rich blue coloring. Cobalt is very significant in world
economy. Cobalt is not mined in the United States, so it must be attained from foreign countries.
Gasoline can be produced from crude oil by cobalt molybdate (CoMoO4). This causes cobalt to
be extremely beneficial in society’s economy. Cobalt is considered to have a pretty short half-life
which causes it to be less dangerous. It enters the land by the wind blowing dust and enters the
water by run-off from the rain running through sediments with cobalt. Once penetrated in the
environment, it is unable to be destroyed. Cobalt is good to have in the soil so that plants contain
some amount of it. Yet, if it is too much, it can cause negative health effects (Cobalt -Co).
Now the separation process will be explained. The most common ions of cobalt are
cobaltous (Co2+) and cobaltic (Co3+). It can be separated from tin, nickel, and calcium. First is
the separation of cobalt and tin. In the experiment, 20 c.c. of the solution is dilated to 50 c.c. with
sulfuric acid. It is then heated along with bivalent metallic sulphates which are “prepared by high
temperature reaction of the constituent elements in sealed evacuated tubes. When the metal
sulphide is quite suitable, metathetical reaction between suitable components yields the product”
(Gopalakrishnan). As it is heated more, a precipitate is separated out from the first solution. The
precipitate is filtered through a glass crucible by heating it and washed three times with sulfuric
acid which is then removed by washing it with absolute alcohol. It is then dried around 220o C
and dissolved in hydrochloric acid (Patel). Next is the separation of cobalt and nickel. The most
common ions are nickelous (Ni2+) and nickelic (Ni3+). The separation of the two elements has
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caused a lot of confusion. There are different processes with different levels of efficiency,
complexity, and expense. There is one invention that proves to be efficient. The first method
involves the “precipitated solid phase containing the nickel and cobalt is separated from the
solution by conventional means and then treated with hot concentrated caustic solution” (Bizot).
This is all done when “a sufficient quantity of the desired caustic hydroxide is added directly to
the hot solution to make a mixture containing the requisite concentration of dissolved caustic
hydroxide” (Bizot). Lastly there is the separation of cobalt from calcium. The common ion for
calcium is Ca2+. It can be separated from cobalt by using synergistic mixtures of carboxylic acid
in solvent extractions (Preez and Preston). The separations were established by ion exchange
chromatography. “Pairs of isotopes (one stable and one radioactive) were partially separated on
ion exchange columns using the band elution technique. A combination of radioactive counting
and microanalytical chemistry was used to isotopically assay the samples” (Lee). It is always
important to take safety precautions in any experiment. In these separations, it is important to
prevent spilling and explosions because it can create contaminations and many other hazards.
Safety gear, such as goggles and aprons, is a necessity. Be sure to be familiar with all safety rules
in chemical explosions (Bate and Leddicotte). It is important to be informed how to dispose the
chemicals to prevent any damage. Sustain the chemicals so that they do not pollute anything else.
Water down the chemicals and put them in protective and labeled jars. The hazardous wastes
should be picked up by the Chemical Waste Program (Chemical).
It is easy to see how noteworthy cobalt is. It benefits society in many ways. One way is in
health through providing vitamins and helping to treat cancer. It also helps in the industry
because of it naturally being a magnet. Another main advantage is it being used to seize its blue
shade. Cobalt is an exceptionally influential element.
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Works Cited
Bate, L.C., G.W. Leddicotte. “The Radiochemistry of Cobalt.” Google Documents. 4 Dec. 2010
<http://docs.google.com>.
Bizot, Hyland. “Process for Nickel-Cobalt Separation.” 15 Feb. 1972. Free Patents Online. 20042010 <http://www.freepatentsonline.com/3642440.html>.
Chemical Waste Program FAQs. Stanford University
<http://www.stanford.edu/dept/EHS/prod/enviro/waste/Waste_FAQs.html>.
Cobalt-Co. 1998-2009. Lenntech Water Treatment & Purification Holding B.V
<http://www.lenntech.com/periodic/elements/co.htm>.
Electron Configuration. Thinkquest
<http://library.thinkquest.org/10429/low/eleconfig/electron.htm>.
Elements – Cobalt (Co). 2008-2010. ChemicalAid
<http://www.chemicalaid.com/element.php?symbol=Co>.
Everett, Mr. “Cobalt.” 21 December 2010
< http://www.mrteverett.com/Chemistry/pdictable/q_elements.asp?Symbol=Co>.
Gopalakrishnan, J. “Preparation of Some Transition Metal Sulphides.” Springer, Part of Springer
Science and Business Media
<http://resources.metapress.com/pdfpreview.axd?code=m175334601760m57&size=large
st>.
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Isotopes of Cobalt.1 November 2010. Wikipedia.
<http://en.wikipedia.org/wiki/Isotopes_of_cobalt>.
Lee, D.A. “Separation of Isotopes of Selected Divalent Elements by Ion Exchange.”
ScienceDirect. 7 May 2003.
<http://www.sciencedirect.com/science>.
Newton, David E. Chemical Elements from Carbon to Krypton. Farmington Hills, MI: The Gale
Group, 1999. Print.
Patel, S.R. “The Preparation of the Double Sulphates of Tin and Certain Bivalent Metals.”
Springer, Part of Springer Science and Business Media
<http://www.springerlink.com/content/p80m4l14r4854m67/>.
Preez, A.C., Preston, J.S. “Separation of Nickel and Cobalt from Calcium, Magnesium and
Manganese by Solvent Extraction with Synergistic Mixtures of Carboxylic Acids.” The
Journal of The South African Institute of Mining and Metallurgy. July 2004
<http://www.saimm.co.za/Journal/v104n06p333.pdf>.
Smith, Richard F. Chemistry for the Million. New York: Charles Scribner’s Sons, 1972. Print.
Stwertka, Albert. A Guide of the Elements. New York: Oxford University Press, 1996. Print.
Yinon, Bentor. Periodic Table: Cobalt. Dec. 11, 2010
<http://www.chemicalelements.com/elements/co.html>.
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Appendix A
Electron Dot Diagram:
x
Co
x
(Everett)
(Elements – Cobalt (Co))
Appendix B
List of Isotopes:
Decay
Isotop
mechanis
Half life
e
m
44
Co-50
Co-51
positron
millisecon
emission
d
positron
Unmeasur
emission
ed
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Co-52
Co-53
positron
0.12
emission
second
positron
0.24
emission
second
193.2
Co-54
positron
millisecon
emission
d
positron
Co-55
emission
17.53 h
electron
capture,
positron
Co-56
emission
77.3 d
electron
Co-57
capture
271.8 d
electron
Co-58
capture
70.88 d
Co-59
stable
∞
Co-60
beta decay
5.271 yr
Co-61
beta decay
1.65 hr
Co-62
beta decay
1.5 min
27.5
Co-63
beta decay
second
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0.30
Co-64
beta decay
second
1.17
Co-65
beta decay
second
0.190
Co-66
beta decay
second
0.43
Co-67
beta decay
second
0.20
Co-68
beta decay
second
0.22
Co-69
beta decay
second
0.13
Co-70
beta decay
second
0.21
Co-71
beta decay
second
90
millisecon
Co-72
beta decay
(Isotopes of Cobalt)
d
Field 11
Flow Diagram
Separation of
cobalt, nickel, tin,
and calcium:
NiSnCoCa
H2SO4 is
added
Heated with
bivalent
metallic
sulphates
Washed in
H2SO4
Washed with
absolute alcohol
Conventional
Means, treated with
concentrated
caustic solution
Use R-COOH
in solvent
extractions
Used by band
elution
technique
OH added to
hot solution
Makes a mixture
of concentration
of dissolved OH
Radioactive
counting
Microanalytical
Chemistry
Dried at 220oC
Dissolved in
HCl
Sn is
separated
Ni is
separated
Ca is
separated