MICA
SCRAP
Scrap
mica basically, is a mica that is below specifications and not
suitable for use as sheet mica, because of size, or quality.
It is a by-product of mining, trimming, and fabricating sheet
mica. Scrap mica is Classified and marketed in the following
grades:
Mine
Scrap : Scrap mica is obtained in course of cobbing, rifting
and dressing crude mica as extracted from the mine, by means
of a sickle, as well as, recovered by means of hammer-crushing
cross-grained mica which cannot be used as sheet mica for commercial
purposes, is classified as mine scrap. It is screened over 1.9
sq.cm (or 0.75 sq.inch) openings, and have an average size between
25-50 mm (1-2 inches), and thickness ranging between 0.25-1.5
mm (0.010-0.060 inches). All mine scrap must be clean, dry ,
hard, free from mineral and non-mineral impurities, such as:
Quartz, felspar, garnet, tourmaline, stones, mud-stained or
biotite mica, Clay, sand, as well as, other foreign inclusions,
viz:paper, wood-leaves, straw, jute-strings, nails or any other
iron-contents etc. It is packed for export in string new gunny
(jute) bags containing 50 kilos net weight packings. Mine scrap
is primarily used as, paints, electrodes, oil-well drillings,
asphalt roofings, tyre, gypsum plaster board etc. Increasing
quantities of superior quality mine scrap are now used for manufacturing
of mica paper or reconstituted mica as a basic raw material.
Factory
Scrap or cuttings: Scrap Mica or mica cutting obtained in
course of trimming and dressing sheet mica in the factory by
sharp knife, as well as recovered during cutting and stamping
sheet mica into pieces of definite size and shape by sear and
punch is classified as factory scrap or cuttings. Factory scrap
is screened over 1.3 sq.cm (or half inch square) openings, and
have an average size between 0.12-0.50 cm (0.5-2 inches) and
thickness ranging between .015-0.5 mm (0.006-.020 inches). All
factory scrap or cuttings must be absolutely pure, fresh, clean,
hard and substantially free from mineral and non-mineral impurities
and other foreign inclusions. It is a highest grade and quality
of scrap mica, which is mostly used in forming mica paper or
reconstituted mica.
India
enjoys vast resources and deposits of Sheet Mica and produces
worlds finest quality of Mine and Factory Scrap, because all
of it is produced in course of Sheet Mica Production. Its present
annual output of Scrap Mica is approximately 40,000 tonnes,
which is next to the United States of America who are having
worlds largest known resources of Scrap Mica with an average
annual production of approximately 100,000tonnes. However, the
majority of scrap mica produced in the United States is recovered
as a by-product or co-product from domestic felspar and kaolin
benifications obtained from open quarries, as well as, from
other micaceous rocks. They are, therefore, of far inferior
quality as compared to Indian grade and quality of scrap mica
and are only suitable for use as raw material for ground mica
industries. The United States has no economic resources of Sheet
mica, its production of sheet mica having declined to almost
nil. As a result, its production of superior quality scrap mica,
suitable for use in reconstituted mica paper, has completely
declined. As such India remains World's primary source of supply
of superior grade and quality of scrap mica essential for use
in reconstituted mica paper and ground mica Pearlscent Pigment,
Cosmetic etc industries.
As
per the forecasts of economic indicators, namely, US Federal
Reserve Board (FRB), based on statistical projections derived
from analysis of historical time series data, it is estimated
that the probable world demand for scrap mica is expected to
have an average annual growth rate of 2.5 per cent, which means,
that the present annual world demand of 200,000 tonnes is likely
to be increased to 325,000 tonnes, if not more, by the end of
the century because of steady increase in demand for Ground
Mica, Reconstituted Mica Paper, Pearlscent Pigment, Cosmetic
industries etc.
(0.007
Inch), is called Block Mica. Block Mica is obtained in size as
large as 30 to 35 cm.sq. (12 to 14 Inches sq) beyond which is
practically rare and far too expensive. It is available in sheets
with an average thickness between 0.18 - 0.75mm (0.007 - 0.030
Inch). Block Mica is supplied both in natural (random) and calibrated
thickness as per customers demand.
Knife
dressed Sheet Mica in any specified range of thickness between
0.05 upto 0.18 mm (0.002 to 0.007 Inch), is called Thin Mica.
Pieces
of high quality Mica having thickness generally less than 2
mils are classified as Condensor Films. These Films are used
in the manufacture of Silver Mica Plates used in Mica Capacitors.
Laminae
split from block and thin Mica, the thickness of Ten Sheets
of which taken together does not exceed 0.30 mm (0.012 Inch),
is called Splitting Mica. Splitting Mica chiefly is used in
the manufacture of Built-Up Mica or Micanite products as raw
material for ultimate use as an Insulating Material.