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Hello, we have silica sand, we have a bank of
at least **0 **0 tons, and have another bank that can supply 4
million tons would like to now whats the percentage of purity your
looking for, we have a high percentage that gave us on labs
checkups for *9.2% of purity, and what grade are you intredted on
your product , we are located at Hermosillo Sonora Mexico. We have
one of the largest Deposits of the region with the best
purity.
And we have an inmense Deposit of Perlite that
can reach at least *4 million tons if your intrested. we can Send
all around the world, we have to check out or FOB, and we have
worked on this for some years now.
Silica sand is
one of the most common varieties of sand found
in the world. It is used for a wide range of applications, and can
be purchased from various suppliers throughout
the world. Silica sand is
used in industrial processing, to make glass, as fill, and to
create molds and castings.
Sand is the general term
for broken down granules of minerals or rocks,
technically between about one-sixteenth of a millimeter to two
millimeters in diameter, falling between silt and gravel in the
spectrum of sizes. There are many varieties of sand in the world, each
with their own unique composition and qualities. The white sandy
beaches of iconic tropical destinations, for example, are made up
primarily of limestone that has been broken down, while
many black sands are either volcanic in origin or
contain magnetite. Other sands have high levels of iron in
them, and so are rich and yellow in
color.
The most common mineral in the Earth’s
continental crust is quartz, and most silica sand is made up of broken
down quartz crystals. Silica is another name
for silicon dioxide, SiO2, of which quartz is a specific
latticed structure. So silica sand is quartz that over
the years, through the work of water and wind, has been broken down
into tiny granules. These granules can be used for many different
purposes, and can be found in most non-tropical regions of the
world.
Silica sand is used throughout the world, and
in so many different ways it is hard to imagine a world without it.
From water filtration, to glass manufacture, to industrial casting,
to sand blasting, to producing concrete, to adding texture to slick
roads, silica sand impacts every aspect of daily life. Many
industrial suppliers carry silica sand in bulk quantities, while
some smaller household stores sell it in smaller amounts for home
or home construction use. One of the major uses of silica sand in
the modern world is as an ingredient in industrial concrete. Silica
sand produces the bulk of a great deal of concrete, although some
concrete bypasses its use for safety and strength reasons. At
industrial scales, silica sand can cost less than $0.*0 US Dollars
(USD) per pound, while the consumer rate is around $1.*0 USD per
pound.
Because of the fine grains involved in silica
sand, it can present a health risk if not properly handled. In
projects where products containing silica sand are being cut or
pounded, such as demolition projects involving concrete, or
sandblasting operations, care must be taken to keep the silica sand
out of the lungs. Failure to wear a respirator or mask can result
in lung irritation, and prolonged exposure can cause a chronic
condition known as silicosis. Silicosis has no ready treatment, and
can cause severe pain or death. Additionally, silicosis increases
the likelihood of secondary infections, such as tuberculosis, and
has been linked to an increased incidence of lung cancer. As a
result, all materials containing more than 0.1% of silica sand must
be clearly labeled, and workplace health codes apply.
SILICA is the most
abundant mineral found in the crust of the earth. It forms an
important constituent of practically all rock-forming minerals. It
is found in a variety of forms, as quartz crystals, massive forming
hills, quartz sand (silica sand), sandstone, quartzite, tripoli,
diatomite, flint, opal, chalcedonic forms like agate, onyx etc.,
and in with numerous other forms depending upon colour such as
purple quartz (amethyst), smoky quartz, yellow quartz or false
topaz (citrine), rose quartz and milky quartz. Only pure quartz
crystal or rock crystal, untwinned, clear, free from any inclusion,
has an important property:
It expands
(mechanically) under the influence of electric current and
conversely pressure induces a measurable electric current. This
property is known as piezoelectricity. The current thus developed
is called piezoelectric current.
This property resulting
from the asymmetry of its atomic groups makes quartz an effective
transducer for coverting electrical energy into mechanical energy
and vice-versa. This property in quartz crystals was discovered in
******2 by Pierre and Jacques Curie and remained a laboratory
curiosity till in ***1 when W.G. Cady, a physicist, discovered that
quartz plates could be used to control the frequency of wireless
transmission circuits.
This discovery
marked the dawn of quartz crystal application in modern
communication equipments. A very thin plate of quartz is so cut
that the frequency of the oscillating circuit corresponds with the
quartz plate and when such plate is inserted in a radio receiving
set or radio transmitter it prevents frequencies from wandering and
deviation and greatly reduces interference.
Quartz plate
is used in controlling frequencies in air and water media as well.
It is largely used in radio circuit, radar, ultrasonic and in
multiple telephone lines. Quartz plates keep the bradcast on the
right beam.
Quartz cystals
cut into prisms, wedges and lenses are used for microscopes and
other optical instruments. Quartz wedge is the commonest accessory
which students use in the petrological microscope.
A number of
other crystals giving piezoelectricity are known but none compares
with quartz. Chemically prepared Rochelle salt and Barium titanate
have been found good substitutes for piwzoelectric
quartz.
The commonest use of
quartz and glass-sand, also referred to as silica-sand, is in the
manufacture of glass. Great advancement has been made in the
manufacture of translucent, transparent, coloured and clear glass
in sheets or in glassware.
The size of
the sand grains is important in glass industry. It should be
between *0 to *0 mesh (BSS). It should be of high purity containing
a minimum of *8% SiO2. In the manufacture of
colourless glass the iron content (Fe2O3) should not exceed 0.*4%.
for optical purposes, the presence of iron oxide
(Fe2O3) more than 0.**8% is not
tolerated.
Iron and
chromium are both objectionable impurities in glass-sand. The
minutest presence of these impurities gives colour effect in the
glass melt. Glass is manufactured by melting a mixture in suitable
proportion of felspar, dolomite, limestone and soda ash together
with glass-sand at ***0º - ***0ºC in the furnace when clear molten
glass is formed.
The average
composition of the mixture by parts is: soda ash 1; silica sand 2½;
limestone / dolomite ¼; borax 1/**0; saltpetre 1/**0; felspar 1/*0
and selenium 1/****0. Selenium is added to neutralise the colour
effect imparted by the presence of iron
oxide.
Twelve grams
of selenium are sufficient to neutralise the colour effect of one
tonne glass containing 0.*5% Fe2O3. Borax is used to
manufacture borosilicate glass of low alkali content including
laboratory wares and optical glass. Boron confers a low
co-efficient of expansion, increases resistance to mechanical and
thermal shocks and gives a bright and pleasing appearance to
glass.
Abrasives Glass-sand free from
organic and clayey impurities is used in the manufacture of
sand-paper, abrasive cloth etc. generally sands crushed from
sandstone and quartzite are used. River-borne sands are unsuitable
as they do not possess the angular faces.
Refractory Quartzite, sandstone,
quartz and other siliceous rocks lime mica schists are used in the
manufacture of silica bricks. Quartzite contains mainly silica and
has high refractoriness. The purity of raw material i.e., the high
silica content is essential with least possible
Al2O3. Phase diagram study has
sown that even about 5% Al2O3 present brings down
the refractoriness from ***8ºC to ***5ºC when eutectic is formed.
The presence of 0.*1% Al2O3 lowers the
refractoriness of silica by 4.8ºF and 0.4% of
Al2O3 by
**0ºF. Silica-rock of metamorphic origin is better than that of
igneous origin because silica grains cemented with cristobalite and
tridymite are stable phases of silica. Silica bricks are used in
the steel industry. The importance of silica bricks is fast losing
ground because of a gradual change in the practice of manufacturing
steel by basic hearth furnace. L.D. process also eliminates much
use of silica bricks as instead dolimite bricks are used. At
present the estimated rate of consumption of silica bricks in the
domestic steel plants in open hearth process using silica roof is 8
kg. per ingot tonne of steel as against 2.8 kg. consumed in the
advanced countries.
Metallurgical Quartz and quartzite are
used in making ferro-silicon for the manufacture of silicon steel.
The specification of quartz and quartzite provided by the industry
manufacturing ferro-silicon is as follows:
Ball mill use Rounded pebbles of
chalcedony are used in ball mills for finer crushing of minerals
like felspar, calcite, and barytes. Chalcedony being the
cryptocrystalline variety of silica is very hard and has good
abrasive effect on the material to be pulverized. Some of the ball
mills use steel shots for this purpose. Chalcedony pebbles are used
to advantage where product absolutely free from iron contamination
is required.
The agate
pieces after cutting to requisite sizes and shapes are utilized in
the manufacture of fulcra of scientific balances and making edges,
planes and bearing of precision instruments. Cambay and Varanasi
are important agate cutting centres. Big pebbles are used for
making mortar and pestle.
Glass-sand in
large quantities is used as moulding sand in the foundry industry,
as body constituent in the ceramic industry in the preparation of
glazes and sometimes added to the raw material for cement
manufacture to balance SiO2, Al2O3 and
Fe2O3 percentages. Silica
flour made by grinding silica sand is used in paints. Paint
manufacturers generally prefer diatomite powder which has a wide
covering powder.
Take Note Silica is a specialist
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