FIELD OF INVENTION
The present invention generally relates to a process and device for sampling of
slag from the blast furnaces. More particularly, the invention relates to an
improved method for sampling of slag from blast furnaces. The invention further
relates to a probe device for direct collection of hot liquid slag from the blast
furnace.
BACKGROUND OF INVENTION
Slag is generated at the blast furnaces during the production of iron.
Approximately 250 kg of slag is generated per ton of iron produced. Analysis of
the Slag is essential for controlling the blast furnace operation. Chemical
composition of the slag provides useful data for evaluating its utility as an input
in cement manufacturing.
The steps involved in the analysis of a slag by an X-ray fluorescence method
comprises: powdering the slag; mixing the powered slag with the binder; and
preparation of a pellet that can be exposed to a primary radiation.
The prior art sampling of slag from blast furnaces includes: collection of the
liquid slag from the runner of the blast furnace with a spoon; allowing the liquid
slag to solidify; and cooling the solidified slag with water for ease of handling.
Further, the solidified slag is crushed to smaller pieces and kept in a hot air oven
for drying. It is then powdered to - 200 mesh size in a pulveriser. The powdered

sample is mixed with a binder in a fixed ratio and pressed to a pellet with the
help of a hydraulic press. The pellet is exposed to X rays for analysis.
However, the prior art method of preparing the slab sample for analyzing by a
spectrometer is quite complex and time-consuming. Further the step of mixing
the powdered slag with a binder calls for skilled measurement and maintenance
of the mixing ratio, and any error in the preparation step may lead to incorrect
result while analyzing the slag sample by the spectrometer. Further, the prior art
method is expensive too.
OBJECTS OF INVENTION
It is therefore an object of the invention to propose an improved method for
sampling of slag from blast furnaces, which eliminates the disadvantages of prior
art.
Another object of the invention is to propose an improved method for sampling
of slag from blast furnaces, which enables direct analysis of the slag sample by
an XRF spectrometer without separately preparing the slag sample.
A still another object of the invention is to propose an improved method for
sampling of slag from blast furnaces, which reduces the cycle time for the
analysis.

Yet another object of the invention is to propose an improved method for
sampling of slag from blast furnaces, which eliminates the time and cost for
heating, pulverizing, and pelletising in the sample preparation subprocess.
A further object of the invention is to propose a probe device for direct collection
of hot liquid slag from the blast furnace which can straightway be analyzed by
the spectrometer.
A still further object of the invention is to propose a probe device for direct
collection of hot slag from the blast furnace, which has a frontal portion
configured with card board such that after collection and cooling of the slag, the
front portion of the probe can be broken for taking - out the solidified slag for
sampling.
Yet further object of the invention is to propose a probe device for direct
collection of hot liquid slag from the blast furnace, which can be repetitively used
for sampling by replacing only the frontal portion which is made of cheap
material such as card board.
SUMMARY OF THE INVENTION
Accordingly, there is provided an improved method for sampling of slag from
blast furnaces, comprising the steps of: providing a probe device for direct
collection of hot liquid slag from the blast furnace; dipping the probe device into
the slag runner for a predetermined time of the blast furnace having hot liquid

slag; allowing the probe device to remain in the dipped condition into the slag
runner for a second predetermined time; taking - out the probe device from the
slag runner and allowing the device to cool under ambient condition for a third
predetermined time; breaking the frontal portion of the probe device by using a
small hammer to take- out the slag sample; and directly analyzing the obtained
slag sample by an XRF spectrometer.
Advantages of the improved method are the following :
1. Reduction in cycle time.
2. Elimination of heating, pulverizing and pelletising.
3. Scope for air pollution is eliminated.
4. It enhances the life of the spectrometer, specially the vacuum pump, as
no loose particles can enter into the system.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure -1 - shows a probe device for direct collection of hot liquid slag from the
blast furnace according to the invention.
Figure - 2 - shows a slag sample collected by the probe device of the invention.

DETAIL DESCRIPTION OF THE INVENTION
A probe (P) is designed as shown in Figure 1, for the collection of slag from a
slag runner of the blast furnace. The probe (P) is dipped into the liquid slag, and
it is allowed to stay within the slag runner for at least 15 seconds, so that the
liquid slag enters a collection chamber (1) of the probe (P). The probe is
thereafter taken out form the slag runner and allowed to cool under normal
temperature for about 20 min. The front portion of the probe (P) is formed of a
card board (s) and is broken with the help of a small hammer to take out the
slag sample. The sample thus obtained is directly analyzed by an XRF
spectrometer. This method enables the analyst to eliminate the steps of
powdering, mixing with a binder in a fixed ration, and compressing the mixture
to a pellet.
According to the invention, the probe (P) comprises a cylindrical collection
chamber (1) having a diameter between 35 to 45 mm, and a height in the range
of 8 to 10mm. Both the top (la) and bottom (lb) portions of the chamber (1)
are covered by ceramic discs (2) of same diameter as that of the collection
chamber (1). Thickness of the ceramic discs (2) is maintained between 6 to 8
mm. The liquid slag sample is held in the collection chamber (1) where it is
allowed to solidify and later taken out. A hole of diameter between 8 to 12 mm
on the cylindrical portions serves as an inlet (4) for the liquid slag.

The collection chamber (1) including the two ceramic discs (2) is housed inside a
ceramic casing (3). The ceramic casing (3) is fixed to on e end of a card board
tube (5) of 1000 mm length.
Figure - 2 shows a slag sample collected by the probe device in the form of a
coin.

WE CLAIM
1. An improved method for sampling of slag from blast furnaces, comprising
the steps of:
providing a probe device for direct collection of hot liquid slag
from the blast furnace;
dipping the probe device into the slag runner for a predetermined
time of the blast furnace having hot liquid slag;
allowing the probe device to remain in the dipped condition into
the slag runner for a second predetermined time;
taking - out the probe device from the slag runner and allowing
the device to cool under ambient condition for a third
predetermined time;
breaking the frontal portion of the probe device by using a small
hammer to take- out the slag sample; and
directly analyzing the obtained slag sample by an XRF
spectrometer.

2. The method as claimed in claim 1, wherein the second and third
predetermined time is identical, and wherein the second predetermined
time is 33% more than the first predetermined time.
3. A probe device for direct collection of hot liquid slag from blast furnaces,
comprising :
a collection chamber (1) having a diameter and height to
commensurate with the slag collection schedule;
at least two ceramic discs (2) of diameter identical to that of the
collection chamber (1) covering a top (la) and a bottom (lb)
portions of the chamber (1) a ceramic casing (3) accommodating
the ceramic discs (2);
an inlet (4) provided in the chamber (1) for ingress of liquid slag
from the slag runner; and
a frontal portion constituting a breakable card board tube (5)
attached to the ceramic easing (3).
4. An improved method for sampling of slag from blast furnaces, as
substantially described herein with reference to the accompanying
drawings.

5. A probe device for direct collection of hot liquid slag from blast furnaces,
as substantially described herein with reference to the accompanying
drawings.
Dated this 20stday of April, 2009

This invention relates to a An improved method for sampling of slag from blast furnaces, comprising the steps of; providing a probe device for direct collection of hot liquid slag from the blast furnace; dipping the probe device into the slag runner for a predetermined time of the blast furnace having hot liquid slag;
allowing the probe device to remain in the dipped condition into the slag runner for a second predetermined time; taking - out the probe device from the slag runner and allowing the device to cool under ambient condition for a third predetermined time; breaking the frontal portion of the probe device by using a small hammer to take- out the slag sample; and directly analyzing the obtained slag sample by an XRF spectrometer. The invention further relates to a probe device for direct collection of hot liquid slag from furnaces.