Type:sphalerite,Other minerals, from which zinc is extracted, include smithsonite
(zinc carbonate),
hemimorphite
(zinc silicate),
wurtzite
(another zinc sulfide), and sometimes hydrozincite
(basic zinc carbonate). With the exception of wurtzite, all
these other minerals were formed as a result of weathering processes on the
primordial zinc sulfides.
Chemical composition:Zn
Listing description:
Zinc (pronounced /ˈzɪŋk/ zingk, from
German:
Zink), also known as spelter, is a
metallic chemical
element; it has the symbol Zn and atomic
number 30. It is the first element in group
12 of the periodic table. Zinc is, in some respects,
chemically similar to magnesium, because its ion is of similar size
and its only common oxidation state is +2.
Detailed description:
Zinc is the 24th most abundant element in the Earth's crust and has
five stable isotopes.
The most exploited zinc ore
is sphalerite,
a zinc
sulfide. The largest exploitable deposits are found in Australia, Canada,
and the United States. Zinc production includes froth
flotation of the ore, roasting, and final extraction using electricity (electrowinning).
Brass,
which is an alloy
of copper and zinc, has been used since at least the 10th century BC.
Impure zinc metal was not produced in large scale until the 13th century in
India, while the metal was unknown to Europe until the end of the 16th century.
Alchemists
burned zinc in air to form what they called "philosopher's wool" or "white
snow".
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Characteristics
Physical properties
Zinc, also referred to in nonscientific contexts as spelter, is
a bluish-white, lustrous, diamagnetic metal, though most common commercial grades
of the metal have a dull finish. It is somewhat less dense than iron and has a
hexagonal crystal structure.
The metal is hard and brittle at most temperatures but becomes
malleable between 100 and 150 °C. Above
210 °C, the metal becomes brittle again and can be pulverized by beating.
Zinc is a fair conductor of electricity. For a metal, zinc
has relatively low melting (420 °C) and boiling points (900 °C). Its
melting point is the lowest of all the transition
metals aside from mercury and cadmium.
Many alloys
contain zinc, including brass, an alloy of zinc and copper. Other
metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium and
sodium. While
neither zinc nor zirconium are ferromagnetic,
their alloy ZrZn2 exhibits ferromagnetism below 35 K.
Occurrence
Zinc makes up about 75 ppm (0.0075%) of the Earth's
crust, making it the 24th most abundant element there. Soil contains
5–770 ppm of zinc with an average of 64 ppm. Seawater has only
30 ppb zinc and the atmosphere contains
0.1–4 µg/m3.
The element is normally found in association with other base metals
such as copper and lead in ores. Zinc is a chalcophile , meaning the element has a
low affinity for oxides
and prefers to bond with sulfides. Chalcophiles formed as the crust solidified under
the reducing
conditions of the early Earth's atmosphere. Sphalerite,
which is a form of zinc sulfide, is the most heavily mined zinc-containing ore
because its concentrate contains 60–62% zinc.
Other minerals, from which zinc is extracted, include smithsonite
(zinc carbonate),
hemimorphite
(zinc silicate),
wurtzite
(another zinc sulfide), and sometimes hydrozincite
(basic zinc carbonate). With the exception of wurtzite, all
these other minerals were formed as a result of weathering processes on the
primordial zinc sulfides.
World zinc resources total about 1.8 gigatonnes. Nearly 200 megatonnes
were economically viable in 2008; adding marginally economic and subeconomic
reserves to that number, a total reserve base of 500 megatonnes has been
identified. Large deposits are in Australia, Canada and the United States with
the largest reserves in Iran.
At the current rate of consumption, these reserves are estimated to be depleted
sometime between 2027 and 2055. About 346 megatonnes have been extracted
throughout history to 2002, and one estimate found that about 109 megatonnes of
that remains in use.
Applications
The main end-uses for zinc are as follows:
1.
Galvanizing:
59% - cars and construction
2.
Diecasting:
16% - motor housings, door furniture, toys
4.
Rolled zinc: 6.5% - roofing and
guttering in some parts of Europe, coffins in southern Europe, and batteries
5.
Chemicals: 6.0% - tyres and zinc
cream
6.
Miscellaneous: 2.5% - includes
dust in batteries
Alloys
A widely used alloy which contains zinc is brass, in which copper is
alloyed with anywhere from 3% to 45% zinc, depending upon the type of brass.
Brass is generally more ductile and stronger than copper and has superior corrosion resistance. These properties make it
useful in communication equipment, hardware, musical instruments, and water
valves.
Other widely used alloys that contain zinc include nickel
silver, typewriter metal, soft and aluminium solder, and
commercial bronze.
Zinc is also used in contemporary pipe organs as a substitute for the
traditional lead/tin alloy in pipes.[102]
Alloys of 85–88% zinc, 4–10% copper, and 2–8% aluminium find limited use in
certain types of machine bearings. Zinc is the primary metal used in making American
one cent coins since 1982.[103]
The zinc core is coated with a thin layer of copper to give the impression of a
copper coin. In 1994, 33,200 tonnes (36,600 short tons) of zinc were used
to produce 13.6 billion pennies in the United States.[104]
Other industrial uses
Roughly one quarter of all zinc output, in the United States (2006), is
consumed in the form of zinc compounds;[92]
a variety of which are used industrially. Zinc oxide is widely used as a white
pigment in paints, and as a catalyst in the manufacture of rubber.[10]
It is also used as a heat disperser for the rubber and acts to protect its
polymers from ultraviolet radiation (the same UV protection
is conferred to plastics containing zinc oxide).[10]
The semiconductor
properties of zinc oxide make it useful in varistors and
photocopying products.[111]
The zinc zinc-oxide cycle is a two step thermochemical
process based on zinc and zinc oxide for hydrogen production.[112]
Zinc chloride is often added to lumber as a fire
retardant[113]
and can be used as a wood preservative.[114]
It is also used to make other chemicals.[113]
Zinc
methyl (Zn(CH3)2) is used in a number of organic syntheses.[115]
Zinc
sulfide (ZnS) is used in luminescent pigments such as on the hands of clocks, X-ray and television
screens, and luminous paints.[116]
Crystals of ZnS are used in lasers that operate in the mid-infrared part
of the spectrum.[117]
Zinc
sulfate is a chemical in dyes and pigments.[113]
Zinc
pyrithione is used in antifouling paints.[118]
Zinc has been proposed as a salting
material for nuclear weapons (cobalt is another,
better-known salting material).[121]
A jacket of isotopically enriched 64Zn,
irradiated by the intense high-energy neutron flux from an exploding
thermonuclear weapon, would transmute into the radioactive isotope 65Zn
with a half-life of 244 days and produce massive gamma radiation,
significantly increasing the radioactivity of the weapon's fallout
for several days.[121]
Such a weapon is not known to have ever been built, tested, or used.[121]
65Zn is also used as a tracer
to study how alloys that contain zinc wear out, or the path and the role of
zinc in organisms.[122]
Medicine
Zinc is included in most single tablet over-the-counter daily vitamin
and mineral supplements.[126]
It is believed to possess antioxidant properties, which protect against premature
aging of the skin and muscles of the body, although studies differ as to its
effectiveness.[127]
Zinc also helps speed up the healing process after an injury.[127]
The efficacy of zinc compounds when used to reduce the duration or
severity of cold symptoms is controversial.[128]
Zinc
gluconate glycine and zinc acetate are used in throat
lozenges or tablets to reduce the duration and the severity of cold
symptoms.[129]
Preparations include zinc oxide, zinc acetate, and zinc gluconate.[126]
Zinc gluconate is one compound used for the delivery
of zinc as a dietary supplement
Zinc preparations can protect against sunburn in the
summer and windburn
in the winter.[51]
Applied thinly to a baby's diaper area (perineum) with
each diaper change, it can protect against diaper rash.[51]
The Age-Related Eye Disease Study
determined that zinc can be part of an effective treatment for age-related macular degeneration.[130]
Zinc supplementation is an effective treatment for acrodermatitis enteropathica, a
genetic disorder affecting zinc absorption that was previously fatal to babies
born with it.[51]
Zinc lactate is used in toothpaste to prevent halitosis. Zinc
pyrithione is widely applied in shampoos because of its anti-dandruff
function. Zinc ions are effective antimicrobial agents even at low
concentrations.Gastroenteritis
is strongly attenuated by ingestion of zinc, and this effect could be due to
direct antimicrobial action of the zinc ions in the gastrointestinal tract, or to the absorption
of the zinc and re-release from immune cells (all granulocytes
secrete zinc), or both.
Deficiency
Main article: Zinc deficiency
Zinc deficiency is usually due to insufficient dietary intake, but can
be associated with malabsorption, acrodermatitis enteropathica, chronic
liver disease, chronic renal disease, sickle cell disease, diabetes,
malignancy, and other chronic illnesses.[2]
Symptoms of mild zinc deficiency are diverse.[159]
Clinical outcomes include depressed growth, diarrhea, impotence and delayed
sexual maturation, alopecia, eye and skin lesions, impaired appetite, altered
cognition, impaired host defense properties, defects in carbohydrate utilization,
and reproductive teratogenesis.[154]
Mild zinc deficiency depresses immunity,[168]
although excessive zinc does also.[141]
Animals with a diet deficient in zinc require twice as much food in order to
attain the same weight gain as animals given sufficient zinc.[116]
Packaing
details:
We usually
bag ores in 50kg,100kg,150kg and 200kgs depending on specifications. Now for a
50kg bagged ore it will contain 480 bags for
20ft container,610 bags for 40ft
container, 642 and 674 bags for 48ft and 53ft containers respectively. For a
100kg bagged ore we shall have 240 bags for
20ft container, 305 bags for 40ft
container,329 bags for a 48ft and 344 bags for a 53ft container. However, the
best method to transport ores such as iron is through ship loads such as 25000
,50000, tonnes and so on, because through this way the transporting is less
cumbersome and one can transport more materials at a given time.
PRICE
$2.68/KG
OR $1.21/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
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