TECHNICAL FIELD
[001] The present disclosure relates in general to sinter production in a process plant. More
specifically, the present disclosure relates to measuring amount of iron oxide (FeO) sinter.
BACKGROUND
[002] A sintering plant has become successful for providing an increase in the productivity and
saving coke rate in the blast furnace. The blast furnace demands sinter with a high cold strength,
low Reduction Degradation Index (RDI) and high Reducibility Index (RI), in a very narrow
band of chemistry variation, with the lowest possible fines content, and a good average size.
The chemical and structural composition are very important in sinter. Sinter reducibility, and
sinter quality in general, improves with a higher level of hematite than magnetite, and its
structure improves with a higher level of primary or residual hematite and ferrites than
secondary or precipitated hematite.
[003] Iron oxide (FeO) content is an important control parameter in the sinter plant. When the
chemical composition of an ore mix is fixed, FeO can provide an indication of sintering
conditions, in particular the coke rate. Increase in the FeO content in sinter is found to lower
(improve) the RDI. However, a higher FeO content negatively affects reducibility. It is
important to find an optimum FeO content in order to improve the RDI without altering other
sinter properties.
[004] Currently in process plants, the amount of FeO in sinter is determined at each shift
through chemical analysis in labs. Chemical analysis is a very lengthy and cumbersome
process. Therefore it takes longer time for the process of sinter making which affect the blast
furnace coke rate.
[005] Therefore, there exists a need to determine the FeO content in sinter in real-time and
reduce downtime of the process plant.
[006] The information disclosed in this background of the disclosure section is only for
enhancement of understanding of the general background of the invention and should not be
taken as an acknowledgement or any form of suggestion that this information forms the prior
art already known to a person skilled in the art.

SUMMARY
[007] In an embodiment, the present disclosure discloses a system for measuring iron oxide
(FeO) in sinter in a process plant. The system comprises a current carrying coil placed
proximate to a conveyor belt transporting the sinter. The conveyor belt may be transporting the
sinter to the blast furnace. The system further comprises a circuit configured for measuring a
value of inductance of the current carrying coil and a signal processor configured for
determining an amount of FeO in the sinter based on measurements received from the circuit.
[008] In an embodiment, the present disclosure discloses a method for measuring iron oxide
(FeO) in sinter in a process plant. The method comprises measuring a value of inductance of a
current carrying coil placed proximate to a conveyor belt transporting the sinter, determining a
variation in the value of inductance of the current carrying by comparing the measured value
of inductance with a reference value of inductance and determining an amount of FeO in the
sinter based on the variation in the value of inductance and a weight of the sinter in a zone of
magnetic influence on current carrying coil.
[009] The foregoing summary is illustrative only and is not intended to be in any way limiting.
In addition to the illustrative aspects, embodiments, and features described above, further
aspects, embodiments, and features will become apparent by reference to the drawings and the
following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0010] The novel features and characteristic of the disclosure are set forth in the appended
claims. The disclosure itself, however, as well as a preferred mode of use, further objectives
and advantages thereof, will best be understood by reference to the following detailed
description of an illustrative embodiment when read in conjunction with the accompanying
figures. One or more embodiments are now described, by way of example only, with reference
to the accompanying figures wherein like reference numerals represent like elements and in
which:
[0011] Fig. 1 is an illustration of a system for determining FeO content in sinter in a process
plant, in accordance with an embodiment of the present disclosure;
[0012] Fig. 2 is an illustration of a zone of magnetic influence, in accordance with an
embodiment of the present disclosure;

[0013] Fig. 3 is an illustration of a circuit for measuring inductance in current carrying coil, in
accordance with an embodiment of the present disclosure;
[0014] Fig. 4 illustrates a block diagram of electronic components for determining FeO content
in sinter, in accordance with an embodiment of the present disclosure;
[0015] Fig. 5 is a flowchart illustrating method steps for determining FeO content in sinter, in
accordance with an embodiment of the present disclosure;
[0016] Fig. 6 is an exemplary graph showing a relationship between variation in inductance
and amount of FeO in sinter, in accordance with an embodiment of the present disclosure; and
[0017] Fig. 7 and Fig. 8 are illustration of exemplary GUI showing the readings of the
measurements and calculations in while determining FeO content in sinter, in accordance with
an embodiment of the present disclosure.
[0018] It should be appreciated by those skilled in the art that any block diagrams herein
represent conceptual views of illustrative systems embodying the principles of the present
subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state
transition diagrams, pseudo code, and the like represent various processes which may be
substantially represented in computer readable medium and executed by a computer or
processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION
[0019] In the present document, the word "exemplary" is used herein to mean "serving as an
example, instance, or illustration." Any embodiment or implementation of the present subject
matter described herein as "exemplary" is not necessarily to be construed as preferred or
advantageous over other embodiments.
[0020] While the disclosure is susceptible to various modifications and alternative forms,
specific embodiment thereof has been shown by way of example in the drawings and will be
described in detail below. It should be understood, however that it is not intended to limit the

disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all
modifications, equivalents, and alternative falling within the scope of the disclosure.
[0021] The terms “comprises”, “comprising”, or any other variations thereof, are intended to
cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of
components or steps does not include only those components or steps but may include other
components or steps not expressly listed or inherent to such setup or device or method. In other
words, one or more elements in a system or apparatus proceeded by “comprises… a” does not,
without more constraints, preclude the existence of other elements or additional elements in
the system or apparatus.
[0022] Embodiments of the present disclosure relate to a system and method for determining
iron oxide (FeO) content in sinter. The system is used to determine the FeO content present in
the sinter in real-time while the sinter is transported to a blast furnace in a process plant. The
system uses magnetic properties of components present in the sinter to determine the amount
of FeO. Magnetic inductance principle is used to determine a change in inductance value of a
current carrying coil when a certain amount of sinter is near the current carrying coil. Using
the change in inductance value of the current carrying coil, the amount of FeO is determined.
[0023] Fig. 1 is an illustration of a system for determining FeO content in sinter in a process
plant. Fig. 1 shows an exemplary process plant where sinter (102) is transported to blast furnace
(not shown) on a conveyor belt (101) in a process plant. The process plant may be for example
a sintering plant. The sinter (102) along with other components are heated in the blast furnace
for producing steel. Raw material (iron ore fines) is mixed with other components such as
limestone and coke, and the resulting mixture is called as the sinter (102). Iron ore comprises
magnetite and magnetite influences the properties of the sinter. For example, increase in
magnetite decreases physical strength of pellets of the sinter (102). According to the amount
of magnetite temperature and additives for the blast furnace are determined. The magnetite
content is determined using the below formula:
Magnetite % = 3.222 * FeO % (1)
From equation 1, it is clear that FeO content in the sinter (102) is required to determine the
magnetite content, which is a driving factor for reduction process in the blast furnace. The FeO

is determined based on its magnetic properties, i.e., magnetic permeability. Magnetic
permeability is the measure of the ease with which the magnetic flux lines can settle in a given
material. When a magnetic sample (e.g., sinter (102)) is placed in a magnetic field, the sample
becomes magnetized in the same direction as the flux lines of the applied field, thus increasing
the overall magnetic flux density. The below equation describes the magnetic flux density:
B = µH (2)
Where B – magnetic flux
µ - magnetic permeability
H – magnetizing force
[0024] The proposed system uses coils (104) which is magnetically coupled to the sinter (102)
for determining the amount of FeO in the sinter (102). The coils (104) may be wound around
a frame (103) as shown in the Fig. 1. The frame (103) may be mounted such that the conveyor
below (101) is passed through the coils (104). The coils (104) are energized to carry current,
which results in a magnetic field around the coil (104) according to the principle of
electromagnetic induction. Inductance is a property of a conductor to resist change in current
in the substance and is denoted by L. The inductance L of the coil (104) is given by below
equation:
L = µN2A / l (3)
Where N – number of turns of the coil (104)
A – Area of the coil (104)
l – length of the coil (104)
[0025] The value of inductance L of the coil (104) changes due to the presence of FeO in the
sinter (102). The change in inductance L of the coil (104) can be measured to determine amount
of FeO in the sinter (102).
[0026] The system further comprises a circuit (106) for measuring the inductance L of the coil
(104). Furthermore, the system comprises a signal processor (105) for determining the amount
of FeO in the sinter (102) based on measurements made by the circuit (106).

[0027] In an embodiment, the frame (103) may be made of steel or any other suitable material.
Further, the frame (103) is constructed such that it encircles the conveyor belt (101) as shown
in the Fig. 1. For example, the frame dimensions may be 1000mm in length, 400mm in breadth
and 500 mm in height.
[0028] Fig. 2 is an illustration of a zone of magnetic influence. As described above, the coils
(104) are influenced by the FeO content in the sinter (102) due to their magnetic properties.
The inductance L of the coil (104) may be influenced by the magnetic flux of the FeO at a
certain zone around the coils (104). The zone of influence (201) is shown as an example in the
Fig. 2 and may vary depending on the construction of the coils (104). As shown in the Fig. 2,
the zone of influence (201) may lie on the conveyor belt (101) surrounded by the coils (104).
The pellets of sinter (102) passing through the zone of influence (201) may cause variation in
the inductance value L of the coils (104).
[0029] In an embodiment, a wight of the sinter (102) in the zone of influence (201) may be
determined using a weight sensor (not shown). The weight sensor may be mounted on the
conveyor belt (101) inside the zone of influence (201) or may be placed underneath the
conveyor belt (101) below the zone of influence (201). When the weigh sensor is placed
underneath the conveyor belt (101), the weight of the conveyor belt (101) may be offset from
the measurements of the wight of the sinter (102). The weight of the sinter (102) in the zone of
influence is used to determine the amount of FeO in the sinter (102).
[0030] Fig. 3 is an illustration of the circuit (106) for measuring inductance value L in coils
(104). The circuit (106) shown in the Fig. 3 may be a Maxwell bridge circuit for measuring the
inductance value L of the coils (104). From Fig. 3, R1 and R4 are generally known and fixed
values. Further, R2 and C2 are generally known and variable. R3 and L3 are calculated using
the below equation:

(4)
[0031] Fig. 4 illustrates a block diagram of electronic components for determining FeO content
in the sinter (102). Fig. 4 shows the signal processor (105) comprising a signal generator (401),
an Analog to Digital (A2D) converter (402) and an analyzer (405). Fig. 4 also shows a amplifier
(403), the coils (104), the circuit (106), a rectifier (404), a Distributed Control System (DCS)
(406) and a display (407).
[0032] The signal processor (105) may be connected to the DCS (406) via a communication
network (not shown). The communication network may be a plant network facilitating
communication between various devices in the process plant. The signal processor (105) may
receive an indication from the DCS (406) when the conveyor belt (101) is operated. In an
embodiment, the signal processor (105) may begin to operate after receiving the indication
from the DCS (406). The signal generator (401) generates a signal at a predefined frequency.
For example, the signal may be a 5V sine wave. Further, the amplifier (403) amplifies the signal
generated by the signal generator (401) and supplies the amplified signal to the coils (104). The
coils (104) conduct the amplified signal and a magnetic field is generated in a direction
perpendicular to the direction of flow of current. The coils (104) is also associated with the
inductance L. When the sinter (102) present in the conveyor belt (101) reaches the zone of
influence (201), the FeO in the sinter (102) influences the magnetic field of the coils (104).
Therefore, the inductance L of the coils (104) is varied due to influence of the magnetic field
of the FeO. In an embodiment, the circuit (106) ma measure the inductance L of the coils (104)
before the influence of the magnetic field of the FeO and after the influence of the magnetic
field of the FeO. L1 and L2 may be inductance of the coils (104) measured before and after the
influence of the magnetic field of the FeO on the magnetic field of the coils (104). L1 may act
as a reference value of inductance. In an embodiment, the L1 is measured when sinter (102) is
not present in the zone of influence (201). A variation the inductance (L2 ~ L1) may be
calculated. The variation in the inductance (L2 ~ L1) along with the weight of the sinter (102)
are used to determine the amount of FeO in the sinter (102).

[0033] In an embodiment, the circuit (106) may output a current signal corresponding to
measured inductance value. The rectifier (404) may convert the full wave current signal into
half wave current signal. Further, the rectifier (404) provides the rectified current signal to the
signal processor (105). The A2D converter (402) converts the half wave current signal into
digital signals. Digital signals are easier to process, hence the rectified signal is converted to
digital signal using sampling technique. The A2D converter (402) may sample the rectified
current signal at or greater than Nyquist rate to generate the digital signal.
[0034] In an embodiment, the analyzer (405) is configured to analyze the digital signal and
determine the amount of FeO in the sinter (102). The analyzer (405) may use relationship
between the amount of FeO and the variation in the inductance (L2 ~ L1) and the weight of the
sinter (102) in the zone of influence (201) to determine the amount of FeO in the sinter (102).
In an embodiment, a speed of the conveyor belt (101) may be adjusted according to time taken
by the analyzer (405) to determine the amount of FeO in a sample of the sinter (102) present
on the zone of influence (201). For example, the analyzer (405) may consume 10ms to
determine the amount of FeO in a sample of the sinter (102). Hence, the speed of the conveyor
belt (101) may be adjusted such that a first sample of the sinter (102) passes through the zone
of influence (201) in 10ms – 15ms (considering delay caused in displaying the result or
operating the DCS (406)). Further, when the second sample of the sinter (102) passes through
the zone of influence (201), the signal processor (105) again determines the amount of FeO in
the second sample. Likewise, this procedure is repeated for a plurality of samples. In an
embodiment, the analyzer (405) may also determine the amount of magnetite in the sinter (102)
using equation 1.
[0035] In an embodiment, the analyzer (405) provides the determined amount of FeO in the
sinter (102) to the DCS (406) and / or the display (406). In an embodiment, the DCS (406) may
be configured to automatically control parameters of the blast furnace based on the amount of
FeO in the sinter (102). For example, the DCS (406) may control amount of coke added to the
blast furnace based on the amount of FeO in the sinter (102). Further, the DCS (406) may also
be responsible for controlling the speed of the conveyor belt (101).
[0036] In an embodiment, the determined amount of FeO in the sinter (102) may be displayed
on the display (407). A plant operator may view the amount of FeO in the sinter (102) and may
take appropriate actions. For example, in process plants where chemicals are added manually

into the blast furnace, the plant operator may determine amount of coke that needs to be added
to the bast furnace based on the amount of FeO in the sinter (102).
[0037] Figure 5 is an illustration of a circuit for measuring inductance L in the coils (104). As
illustrated in Figure 3, the method (500) may comprise one or more steps. The method (500)
may be described in the general context of computer executable instructions.
[0038] The order in which the method (500) is described is not intended to be construed as a
limitation, and any number of the described method blocks can be combined in any order to
implement the method. Additionally, individual blocks may be deleted from the methods
without departing from the spirit and scope of the subject matter described herein. Furthermore,
the method can be implemented in any suitable hardware, software, firmware, or combination
thereof.
[0039] At step (501), the circuit (106) measures the value of inductance (L1, L2) of the coils
(104) placed proximate to the conveyor belt (101) transporting the sinter (102). In an
embodiment, the circuit (106) measures the reference value of inductance (L1) of the coils
(104) when the sinter (102) is not present on the conveyor belt (101). Further, the circuit (106)
measures the value of inductance (L2) of the coils (104) when the sinter (102) passes through
the zone of influence (201). In an embodiment, the coils (104) carries current which is provided
by the signal generator (401) via the amplifier (403). As the coils (104) carries current,
magnetic field is generated around the coils (104) and the inductance (L1) (self-inductance) is
developed in the coils (104). The circuit (106) may be configured to measure the self-
inductance (L1) of the coils (104) when the sinter (102) is not placed on the conveyor belt (101)
and the measurement is saved as reference inductance value. When the sinter (102) is closer to
the coils (104), the FeO in the sinter (102) having its own magnetic field interacts with the
magnetic field of the coils (104). Due to the variation in the magnetic field of the coils (104)
the inductance (L1) varies.
[0040] At step (502), the signal processor (105) determines the variation in the value of
inductance (L2 ~ L1) of the coils (104). The signal processor (105) receives each measurement
of inductance (L) from the circuit (106)as described earlier. The signal processor (105) may
store the value of inductance (L1) in its memory (not shown) as the reference inductance value.
Further, the signal processor (105) may compare subsequent inductance values (L2) with the

reference inductance value (L1). A difference between the L2 and L1 indicates that the
inductance of the coils (104) has varied and can be correlated to the sinter (102) transported on
the conveyor belt (101).
[0041] At step (503), the signal processor (105) determines the amount of FeO in the sinter
(102) based on the variation in the values of inductance (L2 ~ L1) and the weight of the sinter
in the zone of influence (201) at the time of measuring the value of inductance (L2). As
described before the weight sensor may be used to measure the weight of the sinter (102) in
the zone of influence (201). The signal processor (105) uses the below equation to determine
the amount of FeO in the sinter (102):
FeO% = K (L2 ~ L1) / weight (5)
Where K – constant.
[0042] Fig. 6 is an exemplary graph showing a relationship between variation in inductance
(L2 ~ L1) and amount of FeO in sinter (102). As seen in the Fig. 6, the amount of FeO in the
sinter (102) is proportional to the variation in the value of inductance (L2 ~ L1). For example,
a variation of 44mH corresponds to 10.9% of FeO in the measured sample of the sinter (102).
[0043] Fig. 7 and Fig. 8 are illustration of exemplary GUI showing the readings of the
measurements and calculations in while determining FeO content in sinter (102). As shown in
the Fig. 7, the readings on the display (407) is illustrated. The reference value of inductance
(L1) is measured as 1.43491mH and the measured inductance corresponds to 15.088mA as
received from the circuit (106). The current output from the circuit (106) is translated to
inductance value and the variation is determined to be 34.65mH. Using equation 5, the amount
of FeO in the sample of the sinter (102) is determined to be 9.30075%. Likewise, in the Fig. 8,
the reference value of inductance (L1) is measured as 1.43491mH and the measured inductance
corresponds to 17.5168mA as received from the circuit (106). The current output from the
circuit (106) is translated to inductance value and the variation is determined to be 42.24mH.
Using equation 5, the amount of FeO in the sample of the sinter (102) is determined to be
10.4466%.

[0044] In an embodiment, the present disclosure provides a system and method for determining
amount of FeO in the sinter (102) in real-time. Advantages of this includes reduced downtime
of the process plant, dynamic operation of blast furnace as DCS (406) can control parameters
of the blast furnace based on result of the proposed system and method. Also, manual
intervention is reduced. Furthermore, the accuracy of the determination is vastly increased as
automated system determines the amount of FeO.
[0045] From the above description, it is evident that the present disclosure provides a secure
mechanism to control the joysticks (103) of the heavy equipment. Thus, injuries and fatalities
can be reduced, while operating the heavy equipment.
[0046] The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the
embodiments", "one or more embodiments", "some embodiments", and "one embodiment"
mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified
otherwise.
[0047] The terms "including", "comprising", “having” and variations thereof mean "including
but not limited to", unless expressly specified otherwise.
[0048] The enumerated listing of items does not imply that any or all of the items are mutually
exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or
more", unless expressly specified otherwise.
[0049] A description of an embodiment with several components in communication with each
other does not imply that all such components are required. On the contrary a variety of optional
components are described to illustrate the wide variety of possible embodiments of the
invention.
[0050] When a single device or article is described herein, it will be readily apparent that more
than one device/article (whether or not they cooperate) may be used in place of a single
device/article. Similarly, where more than one device or article is described herein (whether or
not they cooperate), it will be readily apparent that a single device/article may be used in place
of the more than one device or article or a different number of devices/articles may be used
instead of the shown number of devices or programs. The functionality and/or the features of
a device may be alternatively embodied by one or more other devices which are not explicitly

described as having such functionality/features. Thus, other embodiments of the invention need
not include the device itself.
[0051] Finally, the language used in the specification has been principally selected for
readability and instructional purposes, and it may not have been selected to delineate or
circumscribe the inventive subject matter. It is therefore intended that the scope of the
invention be limited not by this detailed description, but rather by any claims that issue on an
application based here on. Accordingly, the disclosure of the embodiments of the invention is
intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in
the following claims.
[0052] While various aspects and embodiments have been disclosed herein, other aspects and
embodiments will be apparent to those skilled in the art. The various aspects and embodiments
disclosed herein are for purposes of illustration and are not intended to be limiting, with the
true scope being indicated by the following claims.
REFERRAL NUMERALS:
Reference number Description
101 Conveyor belt
102 Sinter
103 Frame
104 Coils
105 Signal processor
106 Circuit
201 Zone of influence
401 Signal generator
402 A2D converter
403 Amplifier
404 Rectifier
405 Analyzer
406 DCS
407 Display

We claim:
1. A system for measuring iron oxide (FeO) in sinter (102) in a process plant, the system
comprising:
a current carrying coil (104) placed proximate to a conveyor belt (101) transporting the
sinter (102);
a circuit (106) configured for measuring a value of inductance (L2) of the current
carrying coil (104); and
a signal processor (105) configured for determining an amount of FeO in the sinter
(102) based on measurements received from the circuit (106).
2. The system as claimed in claim 1, wherein the conveyor belt (101) is configured to pass
through the current carrying coil (106) wound around a frame (103).
3. The system as claimed in claim 1, further comprises a weight sensor mounted on the
conveyor belt (101) to measure the weight of sinter in a zone of magnetic influence (201).
4. The system as claimed in claim 1, wherein the circuit (106) is configured for measuring a
reference value of inductance (L1) when the sinter (102) is not present on the conveyor belt
(101).
5. The system as claimed in claim 1, wherein the signal processor (105) determines the FeO in
the sinter (102), wherein the signal processor (105) is configured to:
determine a variation in the value of inductance of the current carrying coil (104) by
comparing a current value of inductance (L2) with a reference value of inductance (L1); and
determine an amount of FeO in the sinter (102) based on the variation in the value of
inductance and a weight of the sinter (102) in a zone of magnetic influence (201) on current
carrying coil (104).
6. The system as claimed in claim 1, further comprises a display (407) for displaying a value
of FeO in the sinter (102).
7. A method for measuring iron oxide (FeO) in sinter in a process plant, the method comprising:

measuring, by a system, a value of inductance (L2) of a current carrying coil (104)
placed proximate to a conveyor belt (101) transporting the sinter (102);
determining, by the system, a variation in the value of inductance of the current carrying
coil (104) by comparing the measured value of inductance (L2) with a reference value of
inductance (L1); and
determining, by the system, an amount of FeO in the sinter (102) based on the variation
in the value of inductance and a weight of the sinter (102) in a zone of magnetic influence (201)
on the current carrying coil (104).
8. The method as claimed in claim 7, wherein the magnetic zone of influence (201) is present
on the conveyor belt (101).
9. The method as claimed in claim 7, wherein the weight of the sinter (102) is determined by
one of, using a weight sensor, and calculating a volume of the zone of influence (201) on the
conveyor belt (101).

10. The method as claimed in claim 7, wherein the reference value of inductance (L1) is
determined by measuring the value of inductance of the current carrying coil (104) when the
sinter (102) is not present on the conveyor belt (101).
11. The method as claimed in claim 7, wherein the amount of FeO in the sinter (102) is
determined further using the equation FeO % = K(L2 – L1) / weight of sample, wherein K is a
constant, L2 and L1 are the current measurement of value of inductance and reference value of
inductance respectively.

SYSTEM AND METHOD FOR MEASURING FeO IN SINTER