FIELD OF INVENTION
The present invention generally relates to iron ore beneficiation. More
particularly, the present invention relates to an improved float-sink
apparatus to evaluate the yield of iron-ore beneficiation processes.
The invention further relates to a method of testing washability of
raw material in an improved float-sink apparatus.
BACKGROUND OF THE INVENTION
Iron ore beneficiation is traditionally confined to size reduction of the
ore through crushing followed by screening and classification of the
crushed ore at different size ranges. This simple method of
beneficiation of iron ore although produces concentrate of desired
grade, but from a high-grade feed. In the recent years, state -of-the-
art beneficiation equipment are being introduced in iron ore
beneficiation to produce desired grade concentrate, particularly from
a relatively low-grade feed. All such equipment are optimized based
on chemical analysis of feed, its concentrate and reject. However,

this kind of optimization of the equipment constitutes an indirect
method of process evaluation. Such optimization method does not
either portray a theoretical yield or a separation efficiency based on
the tromp curve. The direct and traditional method (involving float-
sink analysis) applicable to other process evaluation cannot be
pursued in case of the iron ore due to lack of availability of heavy
liquids specifically required for the purpose. The only liquid presently
used for this purpose is very costly and not safe to handle and thus
cannot be used on regular basis. Thus, there exists a need to provide
an improved apparatus to evaluate the efficiency of iron-ore
beneficiation process.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose an improved
float-sink apparatus adaptable to evaluate the efficiency and output
quality of iron-ore beneficiation processes, which eliminates the
disadvantages of prior art.

Another object of the invention is to propose an improved float-sink
apparatus adaptable to evaluate the efficiency and output quality of
iron-ore beneficiation processes which is operable with cheaper fluid.
A further object of the invention is to propose an improved float-sink
apparatus adaptable to evaluate the efficiency and output quality of
iron-ore beneficiation processes which is operable with liquid that can
be safely handled.
A still further object of invention is to propose a method of testing
iron-ore materials received as feed for beneficiation process.
SUMMARY OF THE INVENTION
According to the invention there is provided an improved float-sink
apparatus adaptable to evaluate the efficiency and output quality of
iron-ore benification process, comprising a fluidization column
receiving water via a homogeneous chamber from a water tank by
means of an electrically operated pump . The water

flow-rate to the fluidization column is monitored and controlled by a
rotameter, and a bypass line provided with a plurality of valves . A
plurality of pressure transducers operably disposed at different levels
across the length of the fluidization coloumn. The transducers are
connected to a data acquisition device to measure pressure at the
plurality of levels. A plurality of sample tapping points including a
corresponding number of sample tapping lines is provided at the
plurality of levels across the fluidization coloumn. The number of the
pressure transducers and the sample tapping points as identical. The
sample tapping lines each is provided with an electronically operated
valve , and one funnel with a top screen. The separated particles are
manually collected from the screens out of the slurry discharged by
the sample tapping lines .
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1- schematically shows an improved float-sink apparatus
according to the present invention.

Fig. 2- shows a flow-chart depicting the steps of the testing method
according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The improved float-sink apparatus according to the invention is
basically a fluidization column. Water is used as fluid. Water enters
into the fluidization column (FC) through a homogenization chamber
(1). Water is pumped to the fluidization column (FC) from a water
tank (2). Water flow-rate (l/min) to the fluidization column (FC) is
controlled by a bypass line (4) and a valve (3). The flow-rate is
monitored from the readings of a rotameter (5). Superficial water
velocity is calculated from the flow-rate and the cross-sectional area
of the column. A plurality of pressure transducers (PTO-PT6) is
operably disposed across the length of the fluidization column (FC).
Preferably seven transducers could be used which are connected to a
data acquisition device (6) to measure pressure at seven different
levels across the fluidization column (FC). A corresponding number of
sample tapping lines (STL0-STL6) are placed across the length of the
fluidization column (FC). A plurality of sample tapping points (STP0-

STP6) are configured in respect of the sample tapping lines (STL0-
ST6), which discharge the slurry to the respective screens (SR0-SR6)
provided on respective funnels (F0-F6). The sample tapping lines
(STL0-STL6) are arranged at the same levels at which the pressure
transducers (PT0-PT6) are disposed. All the sample tapping lines
(STL0-STL6) are each provided with an electronically-operable valve
(ECV0-ECV6). The separated particles are collected manually from the
screen top. The clean water goes back to the water tank (2). A fresh
water line (FWL) is connected to the tank (2) to supply the fresh
water via an electrically operated pump (8) before each test. The
fluidization column (FC) is made up of steel and Perspex cylindrical
section. The valves (3) and the pressure transducers (PT3) are
disposed in the steel section. The balance portion of the apparatus is
made up of Perspex. The different sections of the apparatus are fixed
through threaded joints (9). Teflon ribbon is used along the threaded
joints (8) while fixing the sections so as to stop any water leakage.

Testing Methods
The float-sink apparatus can be used for testing feed particles, for
example, -10.0 mm material. The material is tested as per the
flowchart shown in Figure 2.
The material will be first screened to different (say 4 nos.) size
fractions. The first size fraction (X1D) will be subjected to fluidization
tests. In the test, the first step is to fluidize the particles and the
complete fluidization will be ensured by a steady pressure drop
across the pressure transducers (PT0 and PT6). The pressure drop will
be noted down across the pressure transducers (PT0-PT3 and PT3-
PT6). In the next step, the electronic valves (ECV0 & ECV3) for the
transducers (TP3 and TP6 ) will be operated to collect fluidized
samples. These samples are X1DH and X1DL. Volume of the samples
will be measured using a measuring cylinder. Volume of the fluidized
column (FC) for which the sample will be collected can also be

measured as height of the portion and the cross-sectional area of the
section can be measured. These two values will provide the voidage
(s) for the X1DH and X1DL when they are fluidized. Therefore, the
testing method will give the following values; pressure drop across
certain height, the height, voidage in the fluidized solids. The density
of the fluid is known. Using these values, specific gravity of the solids
can be measured.

WE CLAIM
1. An improved float-sink apparatus adaptable to evaluate the efficiency and
output quality of iron-ore beneficiation process, comprising:
- a fluidization column (FC) receiving water via a homogeneous chamber
(1) from a water tank (2) by means of an electrically operated pump
(8), water flow-rate to the fluidization column (FC) being monitored
and controlled by a rotameter (5), and a bypass line (4) provided with
a plurality of valves (3);

- a plurality of pressure transducers (PT0-PT6) operably disposed at
different levels across the length of the fluidization coloumn (FC), the
transducers (PT0-PT6) being connected to a data acquisition device (6)
to measure pressure at said plurality levels;
- a plurality of sample tapping points (STP0-STP6) including a
corresponding number of sample tapping lines (STL0-STL6) configured
and provided at said plurality of levels across the fluidization coloumn
(FC), the number of the pressure transducers and the sample tapping
points being identical; and

- the sample tapping lines (STL0-STL6) each provided with an
electronically operated valve (ECV0-EGV6), and one funnel (F0-F6) with
a top screen (SCR0-SCR6), the separated particles being manually
collected from the screens out of the slurry discharged by said sample
tapping lines (STL0-STL6).
Characterized in that said apparatus provides testing data like pressure
drop and height of the column across that point, voidage in fluidized
state, cross-sectional area of the fluidize column, specific gravity of
solid particles, specific gravity of fluid, acceleration due to gravity
which are processed through a programmed logic to evaluate the
efficiency and output quality of iron ore.

2. The apparatus as claimed in claim 1, wherein the fluidization coloumn (FC)
comprises a first section formed of steel, and a second section made of
Perspex, the two sections being affixed via threaded joints (9).
3. The apparatus as claimed in claim 1, wherein the plurality of pressure
transducers (PT0-PT6) comprises seven pressure transducers.
4. The apparatus as claimed in claim 1, wherein the volume of the samples
(X1DH, X1DL) is measured using a measuring cylinder, and wherein the volume
of the fluidized column (FC) is measured as a height of the proportion (h) and
a cross-sectional area (A) of the section of the fluidized column (FC).

ABSTRACT

AN IMPROVED FLOAT-SINK APPARATUS TO EVALUATE THE EFFICIENCY
AND OUTPUT QUALITY OF IRON-ORE BENEFICIATION
An improved float-sink apparatus adaptable to evaluate the efficiency and output
quality of iron-ore beneficiation process, comprising a fluidization column (FC)
receiving water via a homogeneous chamber (1) from a water tank (2) by means of
an electrically operated pump (8), water flow-rate is controlled by a rotameter (5),
and a bypass line (4) provided with a plurality of valves (3); a plurality of pressure
transducers (PT0-PT6) operably disposed across the length of the fluidization
coloumn (FC), the transducers (PT0-PT6) being connected to a data acquisition
device (6) to measure pressure at said plurality of levels; a plurality of sample
tapping points (STP0-STP6) including a corresponding number of sample tapping
lines (STL0-STL6) configured and provided at said plurality of levels across the
fluidization coloumn (FC), and the sample tapping lines (STL0-STL6) each provided
with an electronically operated valve (ECV0-ECV6), and one funnel (F0-F6) with a top
screen (SCR0-SCR6), the separated particles being manually collected from the
screens out of the slurry discharged by said sample tapping lines (STL0-STL6)- The
apparatus provides testing data like pressure drop and height of the column across
that point, voidage in fluidized state, cross-sectional area of the fluidize column,
specific gravity of solid particles, specific gravity of fluid, acceleration due to gravity
which are processed through a programmed logic to evaluate the efficiency and
output quality of iron ore.