IS 3810-1: Solid Mineral Fuels - Vocabulary, Part 1: Terms Relating to Coal Preparation

24 Pages·2002·2.2 MB·English

by  Bureau of Indian Standards

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IS 3810-1 (2002): Solid Mineral Fuels - Vocabulary, Part 1:
Terms Relating to Coal Preparation [PCD 7: Solid Mineral
Fuels]
“!ान $ एक न’ भारत का +नम-ण”
Satyanarayan Gangaram Pitroda
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“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै”
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IS 3810 (Part 1) :2002
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Indian Standard
SOLID MINERAL FUELS — VOCABULARY
PART 1 TERMS RELATING TO COAL PREPARATION
(Second Revision )
Ics 01.040.73; 73.040

0 B[S 2002
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

December 2002 Price Group 8
Solid Mineral FLIelsSectional Committee, PCD 7
FOREWORD
This lndian Standard (Part I) (Second Revision) was adopted by the Bureau of Indian Standards, after the draft
finalized by the Solid Mineral Fuels Sectional Committee had been approved by the Petroleum, Coal and
Related products Division Council.
This standard was first published in 1966 and subsequently revised in 1977 based on ISO recollltlletldatiolls
R 1213- i : 1971. lSO/R 1213-1 has been subsequently revised in 1982 and 1983 which is now available as
IS() [2 13-I : 1993 ‘Solid mineral fuels — Vocabulary — Part I Terms relating to coal preparation’. The
Committee, therefore, decided to revise this standard to incorporate more terlms. ISO 1213-1 : 1993 could not
be adopted as Indian Standard since some of the terms have been modified from the definitions given in ISO
and also a new term. namely, yield/relative density curve has been ordered which isnot existing in ISO standard.
‘Hle composition of the Committee responsible for formulation of this standard is given in Annex A.
IS 3810 (Part 1) :2002
Indian Standard
SOLID MINERAL FUELS — VOCABULARY
PART 1TERMS RELATING TO COAL PREPARATION
(Second Revision )
1SCOPE Recirculation — The operation in which the whole
or part of a product from a process is returned to the
This standard (Part 1) defines terms commonly
feed to aprocess, for example the return ofthe crushed
employed in coal preparation.
overflow from a screen to the screen feed for
rescreening.
2 GENERAL
Reject; Refuse — The material extracted from the
2.1 General Coal Preparation Terms
feed during cleaning, for retreatment or discard.
Cleaned Coal; Clean Coal — Coal produced by a
Segregation — Partial separation of a material into
cleaning process (wet or dry).
its constituents, occurring as a result of differences in
Coal Preparation — Collectively, physical and particle characteristics, such asparticle size or relative
mechanical processes applied to coal to make it density.
suitable for a particular use.
True Middlings; Bone — Middlings so nearly
Coal Cleaning — The treatment of raw coal to lower homogeneous that their quality cannot readily be
the quantity of undesirable constituents, through the improved by crushing and recleaning.
difference in either density or surface properties.
2.2 Cleaning Characteristics
Discard; Dirt; Stone — The material extracted from
the raw coal and finally discarded. Actual Performance Curve — A performance curve
showing the results actually obtained from a coal
False Middlings; [nterbanded Middlings —
preparation treatment<
Middlings in which the particles consist of bands of
coal and shale, and from which the coal may be Ash/Relative Density Curve — The curve obtained
liberated by crushing. from the float-and-sink analysis by plotting the ash
percentages of successive fractions against the mean
Foreign Coal — Coal received at apreparation plant
relative density of the fraction.
from a source other than that to which the plant is
attached. Characteristic Ash Curve — The curve obtained
from the results of a float-and-sink analysis showing,
Imported Coal — Coal coming from a foreign
for any mass percentage of floats (or sinks) the ash
country.
percentage of the highest density (or lowest density)
Low-G rade Coal — Combustible material that has fraction passing into these floats (or sinks), the mass
onIyIimited uses owing to undesirable characteristics percentage being plotted on the ordinate (vertical axis)
(for example ash percentage). and the ash percentage on the abscissa (horizontal
axis).
Middlings — A product of coal preparation that,
because of its ash percentage, is intermediate between Cumulative Curve — Any curve expressing the
coal and discard. results of combining successive relative density
fractions or size fractions.
NOTE — [t follows, therefore,that the relativedensityof
middlings is intermediate between those of coal and discard. Cumulative Floats Curve — The curve obtained from
Mi&llin&maybe reprocessed.
the results of a float-and-sink analysis by plotting the
Run of Mine (ROM) Coal — Coal produced by cumulative mass percentage of floats at each relative
mining operations, before screening, crushing or density against the cumulative ash of the total floats
preparation. at that density.
Raw Coal — Coal that has received no preparation Cumulative Sinks Curve — The curve obtained from
other than possibly screening or crushing. the results of a float-and-sink analysis by plotting the
cumulative mass percentage of sinks at each relative
Raw Coal Feed — Raw coal supplied to a plant or
density against the cumulative ash of the total sinks
machine, in which it undergoes some form of
at that density.
preparation.

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IS3810 (Part 1) :2002
Densimetric Curve; Relative Density Curve — The Design Capacity — The rate of feed atwhich specific
curve obtained from the results of a float-and-sink items of plant must operate continuously and give the
analysis by plotting the cumulative mass percentage guaranteed results on a particular quality of feed.
of tloats or sinks against the relative density.
Equipment Flowsheet — A diagram indicating, by
Expected Performance Curve — A performance standard symbols, the units of equipment used in the
curve showing the expected results of a coal various operational steps carried out within a coal
preparation treatment. preparation plant.
Float-and-Sink Analysis — The division of asample Feed — Material for treatment supplied to an
into relative density fractions having defined limits, appliance or plant.
the amounts of the fractions being expressed as
Liquids Flowsheet — A flowsheet to indicate the flow
percentages of the total sample, commonly with an
of liquids throughout a series of operations.
indication of the ash percentage (and other
characteristics, if required) of each fraction. Materials Flowsheet — A flowsheet principally
concerned with solid materials.
M-Curve; Mayer Curve — A vectorial curve,
obtained by plotting the cumulative ash percentages Mechanical Maximum Capacity — The highest rate
against their cumulative yields, used to express the of feed at which specific items of equipment, not
washability of a coal, plotted on a vectorial diagram subject to performance guarantees, will function on
in which the projection of the vector on the ordinate thetype and quality of feed for which they are supplied.
(vertical axis) represents the percentage ofthe product
Nominal Capacity — A notional figure, expressed
(coal) and the direction of the vector represents the
in mass per hour, used in the title of a flowsheet and
percentage of a particular constituent of the product.
in the general description of a plant, applying to the
Near-Density Curve; Difficulty Curve — The curve plant as a whole and to the specific product under
obtained from the results of a float-and-sink analysis, consideration.
or from the densimetric curve, by plotting the mass
Operational Capacities — Figures given on a
percentage within the limits + 0.1 of a given relative
flowsheet to indicate quantities per unit time passing
density against that relative density.
various points in the plant, taking account of
Performance Curve — Any curve used to show the fluctuations in the rate of supply and composition (as
relationship between properties of coal and results of to size and impurity content).
a specific treatment.
Peak Design Capacity — A rate of feed in excess of
Washability — The amenability of a coal to the design capacity that specific items of plant will
improvement inquality by clean in g, generally through accept for short periods with warranty without
its relative density/ash relationship . necessarily fulfilling the performance guarantee given
in respect of them.
Washability Curve — Any curve obtained from the
results of a float-and-sink analysis permitting the Process Flowsheet — A basic flowsheet indicating
theoretical yield of floats or sinks to be read off. the main operational steps within the plant, the
movement of the various materials between the steps
NOTE — TINfollowing are the five main types ofwasbability
and the final products obtained, and often also the
curves:
a) Characteristic ash curve; average mass flow at various points in the plant.
b) Cumulative floats curve;
Weighted Flowsheet; Capacity Flowsheet — A
c) Cumulative sinks curve;
materials flowsheet used in the design of a plant,
d) [)ensimctric (relative density) curve; and
including statements of the mass flow per hour at
e) Near density curve,
principal points in the plant.
Yield/Relative Density Curve – The curve obtained
from the tloat-and-sink analysis by plotting the yield 3 SIZING
percentages of successive fractions against the mean
3.1 General
relative density of the fraction,
Classification — The separation of particles according
2.3 Capacity and Throughput to their size, density and shape by control of their
settling rate through a fluid medium.
Basic Fiowsheet — A schematic diagram representing
the various preparation process stages inthe treatment Dust — Particles of solid material sufficiently fine to
of the raw coal. allow suspension in air (see a/so 5.4).
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[S 3810 (Part 1) :2002
Fines — Coal having amaximum particle size usually Effective Area (Screen); Working Area
less than 3 mm, and having no lower limit. (Deprecated) — The nominal area less any area
occupied by fixings or supports that obstruct the
NOTI; — ‘i% upper limit may vary widely. To avoid confusion
passage of material over or through the screen deck.
[heterm shrruid always bequalified bystating thenominal size.
Mean Size — The weighted average particle size of Fines Removal — The removal of fine particles from
any salmple, batch or consignment of particulate a feed material, by either wet or dry methods, to
material. facilitate treatment or utilization of the remainder.
NOIE — Several bases for calculating mean size have been Misplaced Undersize — Particles inascreen overflow
proposed, giving results that vary widely for the same size that are smaller than a reference size.
distribution. The method ofcalculation should, therefore, always
bestated whenever results arereported. Misplaced Material (Screening) — Undersize
contained in the overflow, or oversize contained in
Nominal Size; Limiting Size — The limit or limits
the underflow.
of particle size used to describe a product of a sizing
operation. Misplaced Oversize — Particles inascreen underflow
that are larger than a reference size,
Oversize — Material in a product of size greater than
the upper nominal size limit; may be expressed as a Near-Mesh Material; Near-Size Material —
percentage of the product. Material approximating in size to a reference size,
usually within + 25 percent of that reference.
Sizing — Division of amaterial into products between
nominal size limits. Nominal Area (Screen) — The total area ofthe screen
deck exposed to the flow of the material feed,
Size Analysis — The process or the result of the
division of a sample into size fractions, each within Open Area — The ratio of the total area of the
defined Iilmits,the mass or number of particles ineach apertures to the total area of the wire cloth, perforated
fraction being expressed as percentage of the total pIate or wedge-wire panel, expressed as a percentage.
salmple.
Probability Screening — Amethod of screening that,
Sieve Analysis — Size analysis inwhich the division by making extended use ofthe probability of aparticle
is carried out by the use of test sieves. passing through an aperture, allows sizing at fine sizes
to be performed with relatively large apertures.
Smalls — Coal having a maximum particle size
usually less than 25 mm, and having no lower limit. Scqeening — The separation of solid materials of
NOTE —The upper limit may vary widely, Toavoid confusion, different sizes, by causing part to remain on a surface

lheterm should always bequalitied by stating the nominal size, provided with apertures through which the remainder

passes.
Undersize — Material in a product of size smaller
[ban the lower nominal size limit; may be expressed Screen
as a percentage of the product.
a) A device for carrying out the operation of
3.2 Screening screening; and
b) A commonly used abbreviation for screen
Amplitude — The maximum displacement from the
deck orscreening surface, for example woven-
mean position in an oscillating motion.
wire screen.
Nt.)’l’~—Inthe case ofascreen having astraight linemotion or
elliptical motion, itishalf ofthe total movement orhalf ofthe Screen Overflow — That portion of the feed material
major axis otfhe ellipse. Inthecase ofacircular motion, itisthe discharged from the screen deck without having passed
!-adiosol’the circle, through the apertures.
Aperture Size — The dimension or dimensions
Screen Underflow — That portion ofthe feed material
defining the opening inthe screening surface, qualified
that has passed through the apertures in ascreen deck.
as to the shape of aperture, for example ‘round-hole’,
‘square-mesh’, ‘long-slot’. Sieve
Desliming — The removal of slimes from coal or a a) Generally, ascreen of relatively small area, and
mixture of coal and water, however accomplished.
b) Particularly, a screen used for size analysis.
Dedusting — Fines removal by dry methods.
Stroke; Throw — The distance between the extreme
Dry Screening — The screening of solid materials of positions of an osci Ilating or vibrating motion, that
different sizes without the aid of water. is, the stroke is equal to twice the amplitude.

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IS 3810 (Part 1) :2002
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Wet Screening — The screening of solid materials Sizing Screen(s); Grading Screen(s), Classifying
of different sizes with the aid of water. Screen(s) (Deprecated) — A screen or set of screens
normally used for dividing a product (for exaimple
3.3 Parts of Screens
clean coal) into a range of sizes.
Loose-Rod Deck — A screening surface consisting
Undersize Control Screen; Breakage Screen
of loosely held parallel rods positioned at right angles
(Deprecated) — A screen used for the removal or
to the flow of material over the screen. undersize from a product.
Relieving Deck — A screen plate having large
3.5 Screens According to Principle of Construction
apertures mounted over the screening deck to reduce
the load and wear thereon. Bar Screen — A stationary inclined screen,
comprising longitudinal bars, spaced at intervals, onto
Screen Deck; Screening Surface — A surface
which the material is fed at the upper end.
provided with apertures of specified size for carrying
out the operation of screening. Grizzly — A rugged screen for rough sizing at
comparatively large size (for example >150 mm).
Screen Plate — A plate provided with apertures of
specified size and range for use as a screen deck. NOTE —Agrizzly cancomprise fixed ormoving bars, discs, or
shaped tumblers orrollers.
Screen Cloth; Screen Mesh — A mesh of wires
Jigging Screen; Reciprocating Screen; Shaking
woven in a consistent manner to form the ape~tures.
Screen (Deprecated) — A screen to which. a
Wedge-Wire Deck; Wedge-Wire Sieve — A screen combined horizontal and vertical motion is imparted,
deck, comprising wires of wedge-shaped cross-section normally by a crankshaft and connecting rod, the
spaced from each other at afixed dimension, inwhich screen deck being horizontal or inclined at a smal I
the underflow passes through an aperture of increasing angle.
cross-section.
Multi-Deck Screen — A screen having two or more
NOTE — Normally, aloose-rod deck isused only onhigh-speed superimposed screening surfaces mounted rigidly
vibrating screens.
within a common frame.
3.4 Screens According to Purpose Resonance Screen — A screen having a period of
oscillation at or very close to the natural period of
Dewatering Screen — A screen used for the
oscillation of the resilient mounting.
separation of water from solids.
Rotating Probability Screen — A device for
Deslim ing Screen — A screen used for the removal
of slimes from larger particles, u sually with the aid of probability screening, consisting of a rotating
water sprays. horizontal deck having radial spokes, the separation
point being obtained by varying the rotational speed.
Guard Screen; Oversize Control Screen — Ascreen
Roll Screen — A screen consisting of a number of
used to prevent the entry into a machine of coarse
horizontal rotating shafts, fitted with elements
particle which can interfere with its operation.
arranged to provide screening apertures.
Primary Screen; Raw Coal Screen — A screen used
to divide coal (usually raw coal) into sizes more Single-Deck Screen — Ascreen having one screening
suitable for the subsequent cleaning of some or all of surface, not necessarily limited to one size or shape of
them. aperture.
Rinsing Screen; Spray Screen — A screen tfsed for Sieve Bend — A device for the sizing of fine particles
the removal of fine solids by spraying, especially dense suspended in water by means of a stationary curved
medium solids present among or adhering to larger panel, usually of wedge-wire, the aperture of which is
particles. at right angles to the flow of feed, whereby the finer
particles are removed with the bulk of the water in
Run-of-mine Screen — A screen used for dividing
the underflow.
run-of-mine coal into two or more sizes for further
treatment or disposal. Trammel Screen; Revolving Screen — A screen in
which the screening surface is formed into a cylinder
NO’TE— Arun-of-mine screen isusually employed toremove
or frustum of a cone, mounted upon a horizontal or
the Iargest pieces forcrushing andre-addkion tothe run-of-mine
near horizontal rotating shaft, or on revolving rollers.
coal.
Slurry Screen — A screen used to recover and de- Vibrating Screen — Ascreen oscillated at high speed
water granular products from circulating water in a by either mechanical or electrical means.
coal preparation plant.

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IS 3810 (Part 1) :2002
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NOW —The amplitude ofmovement ofthevibrating screen is Rinsing Water; Spray Water — Water used to
smaller than that of the jigging screen, and its frequency of remove tine particles from larger sizes.
oscillation ishigher.
Suspension — A mixture of solid particles and water
3.6 Sizing in a Current of Air or Water
or air in which the solid particles are completely and
Air Classification — The process of sizing in a individually supported.
current of air.
Slimes — Extremely fine particles in suspension or
Classifier — A device that separates particles, adhering to larger particles.
according to their size, shape and density, by physical
Slurry (Coal Preparation) — Fine particles
means other than screening.
concentrated in aportion of the circulating water and
Cyclone Classifier — A device for classification by water-borne for treatment or disposal.
centrifugal means of fine particles suspended inafluid,
Teeter (In); Fluidized Suspension (In) — The
whereby the coarser particles are discharged tlom the
condition of a suspension of solids in an upward-
apex of the vessel, and the finer particles are removed
moving current of water or air, whereby the support
with the buIkof the fluid at the overflow orifice.
given to the particles reduces the internal friction
between them to such an extent that the suspension
4 CLEANING
acquires fluid or partially fluid properties.
4.1 General
Wet Cleaning — The mechanical separation of
Circulating Water — The water in the water circuit. impurities from coal by methods involving the use of
a liquid.
Closed Water Circuit — A water circuit designed so
that the only water added is that necessary to replace Washery — A coal preparation plant in which a wet
the loss on the washery products and that due to cleaning process is carried out.
atmospheric evaporation.
Washery Products — The final products from a
Dry Cleaning — The separation of impurities from washery.
coal by manual or mechanical methods that avoid the
use ofa liquid. Water Circuit — The complete system of pipelines,
pumps, sumps, tanks, launders and accessories used
Froth Flotation — A process for cleaning fine ‘coal
for the circulation of water in a washery.
inwhich the coaI, with the aid of areagent or reagents,
becomes attached to air bubbles in a liquid medium Waste Water; Surplus Water, Bleed Water
and floats as a froth. (Deprecated) — Excess water allowed to run to waste
from the water circuit.
Head Tank — A tank or vessel in the water circuit

that is used to maintain the delivery pressure of the 4.2 Dry cleaning
water by constant level to the washing units.
Air Jig — A machine in which the feed is stratitied
Launder — A trough or channel along which liquids by means of pulsating currents of air and from which
or a mixture of liquids and solids flow. the statified products are separately removed.
Middlings Elevator — An elevator that removes
Dry Cleaning Table — An apparatus in which dry
middlings for further treatment or for disposal as an
cleaning isachieved by the application of air currents
inferior product.
and agitation to a layer of feed of controlled depth
Make-up Water — Water supplied to a plant to moved along the surface of the table, usually by a
replace that lost from the circuit. reciprocating action.
Pump Sump — A tank into which the process water Hand Cleaning— The removal by hand of impurities
gravitates and from which it is re-circulated by means from coal, or coal from impurities.
of a pump.
Hand Selection — The selection by hand of pieces of
Pit Water; Mine Water — Water from underground coal having certain specific qualities according to
workings or an open-cut mine. surface appearance.
Reject Elevator; Refuse Elevator (Deprecated) — Picking Belt; Picking Table — A continuous
An elevator for removing and draining the reject from conveyor (for example in the form of a rubber belt or
a washing appliance. of a steel apron, steel plate or link construction) on
which raw coal is spread for hand cleaning and/or
Reclean; Rewash — To re-treat aproduct inthe same
hand selection.
or in another plant.

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