FIELD OF THE INVENTION
The present invention relates to a development of a device for holding pellets for
chemical analysis in XRF spectrometer and method of forming the device thereof.
More particularly the invention relates to a device to hold pellets of oxide
materials such as slags, raw materials, fluxes etc for its chemical analysis in XRF
(X-ray fluorescence Spectrometer), which is an essential requirement as process
control activity in any steel making operations.
BACKGROUND OF THE INVENTION
In the existing practice the materials stated above are received in the form of
lumps which are ground to - 200 mesh powder form. Pellets formed from these
powders by pressing the powders in a steel ring to form a pellet as sample for
testing its chemical analysis in a XRF spectrometer.
The standard process of analysis in XRF spectrometer is done by preparing a
sample pellet of slag or raw material, fluxes etc for steel making by pressing
powders of those using a steel ring of diameter in a Herzog make pelletizing
press.

The pellet so formed with the ring is then inserted inside a cassette in a manner
so that the surface of the pressed powder is located centrally on opening of the
cassette on its reverse side. The cassette is then closed by a locking means of
fitting relationship by sliding a top closure with the body of the cassette.
The closed cassette is then placed onto the sample chamber in the XRF
spectrometer.
A gap of 0.8cm is maintained between the pellet and the edge of the cassette in
the existing arrangement. But due to this gap the sample pellet gets frequently
shifted from its central position thus creating hindrance for analysis when the
sample pellet is bombarded by X - rays or gamma rays through studying
spectroscopically secondary radiation characteristic of the elements present.
To ensure accurate test analysis of the sample pellet, it is essential that the
pellet remains in the central position without any shifting during analysis through
the spectrometer.

This invention is aimed to provide a device and method to remove the above
difficulties of prior art to keep the sample pellet in the central position for
accurate chemical analysis.
DESCRIPTION OF THE INVENTION
One of the objective of the invention is to provide within the device a plastic ring
of 5 cm diameter to be placed between the steel ring used for the pellet making
and the cassette holder, thus avoiding any gap of 0.8 cm between steel ring and
cassette edge as was carried out in the prior art.
According to another objective of the invention there is provided a method of
preparing a device by installing a plastic ring with an width approximate to the
gap between the steel ring and cassette edge to maintain the said ring in
register relationship with the steel ring of the pellet and the cassette holder to
maintain the pellet at the central position of the opening of the cassette.

Analysis by XRF spectrometer according to the proposed invention is carried on
by firstly preparing a sample of pellet from the powder materials by compressing
the powders using a steel ring of 4 cm diameter in a Herzog make palletizing
press, forming a plastic ring of 5 cm diameter and having a width of the gap
between the steel ring and the edge of the cassette and inserting the plastic ring
into the cassette followed by the sample pellet held in the steel ring and
subsequently locking the cassette.
The pellet through these forming steps is thus secured to be held in central
position of the cassette opening at its reverse side and sample pellet is then
analyzed for its chemical composition on placing the whole cassette in the
sample chamber of XRF spectrometer by X ray radiation falling on the sample
pellet through the opening of the cassette.
According to the invention there is provided a device to hold a sample pellet of
oxide materials for chemical analysis in a XRF spectrometer comprising a sample
pellet attached to a steel ring when formed on compression of powders of oxide
materials by the said steel ring in a palletizing press and put up in a cassette so

that the surface of the pressed powder is located centrally on the opening of the
cassette, a plastic ring of 5 cm diameter and width amounting to the gap
between the steel ring and the inside wall of the cassette being maintained in
register relationship with its inside surface to the outside surface of steel ring
and being supported by the inner wall of the cassette, a locking means to close
the cassette on the opposite side of the opening of the cassette, the device on
locking is thereafter placed in the sample chamber of the spectrometer for
chemical analysis of the materials of the sample pellet.
According to the invention there is also provided a method of forming a device to
hold a sample pellet of oxide materials for chemical analysis in XRF spectrometer
comprising the steps of inserting a plastic ring of 5 cm diameter and width
amounting to the gap between the steel ring holding the sample pellet formed
on compression by the steel ring of 4 cm diameter in a palletizing press, placing
the sample pellet held in the steel ring in register relationship of its outside
surface to the inside surface of the plastic ring being supported by the extreme
inner wall of cassette, the exposed surface of the pellet being maintained
centrally on the opening of the cassette, closing the cassette at the opposite side
of the opening of the cassette by a press fit sliding locking means and placing
the device so formed with the pellet in the sample chamber of the spectrometer
for chemical analysis of the oxide materials of the pellet.

The invention will be better understood by the following description with reference
to the accompanying drawings in which
Figure 1 represents a pellet of oxide materials formed by pressing using a steel
ring of 4 cm diameter in a Herzog make palletizing press according to
prior art.
Figure 2 represents a cassette with a press fit sliding locking means and an
opening on the reverse side of the cassette closure according to prior
art.
Figure 3 represents the sample pellet held in a steel ring being place in the
cassette when the surface of the sample pellet is located centrally on
the opening of the cassette on the reverse side of the closure side of
the cassette according to the prior practice.
Figure 4 represents the cassette holder with a plastic ring and the sample pellet
held in the steel ring according to the present invention.

Figure 1 shows the sample pellet (1) of oxide materials such as slag, flux and
raw materials for steel making formed on pressing by a steel ring (2) of 4 cm
diameter and held in the said ring with sample pellet being formed in a Herzog
make palletizing press (not shown).
Figure 2 shows a cassette (3) representing also as a cassette holder and cassette
edge/wall. The said cassette has a press fit sliding lock means (4) to be closed
by a closure (not shown) on the locking surface of the cassette. The cassette
holder (3) shows an opening (

5) on the reverse side of the closure side of the
cassette.
Figure 3 shows the cassette (3) in which the sample pellet (1) formed on the
steel ring (2) is placed in the cassette wherein the pellet surface is located
centrally on the opening of the cassette on the reverse side of the cassette
closure. In prior practice the gap between the pellet after placement in the steel
ring and the edge/inner wall of the cassette was maintained at 0.8 cm. The said
cassette being closed by a closure mating at the locking surface was put up in
the sample chamber in the XRF spectrometer for chemical analysis as in the prior
practice. The said cassette could not produce accurate analysis of the sample
pellet material due to shiftment of the pellet from the central position of the
opening (5) when placed in the spectrometer chamber.

Figure 4 shows the device formed according to the present invention. A plastic
ring (6) of 5 cm diameter and width of the gap between the steel ring holding
the sample pellet and the inside wall of the cassette is inserted within the
cassette followed by placement of the sample pellet (2) attached with the steel
ring (2) of 4 cm diameter in such a manner that the inside surface of the plastic
ring (6) and outside surface of the steel ring (2) keep a matching relationship
between themselves and the outside surface of the plastic ring (6) is supported
on the inner wall of the cassette. On closing the cassette by locking arrangement
(4) the whole device cassette is placed in the sample chamber of the
spectrometer for chemical analysis of the materials of the sample pellet.
The developed device for holding the sample pellet ensures accurate chemical
analysis of oxide materials of the pellet maintained through any non shiftment of
the sample when placed in the sample chamber of spectrometer and thus secure
safe process control activity during any steel making process operations.
The proposed invention as narrated and illustrated herein above with an
exemplary embodiment should not be read and construed in a restrictive manner
as various modifications, adaptations and alterations are possible within the
scope and limit of the invention as defined in the encompassed appended claims.

WE CLAIM
1. A device to hold a sample pellet of oxide materials for chemical analysis in a
XRF spectrometer comprising:-
- a plastic ring of 5 cm diameter and a width amounting to the gap between
the steel ring (2) and the inside wall of the cassette (3) being maintained in a
register relationship with its inside surface to the outside surface of the steel
ring (2) and being supported by the inner wall of the cassette (3);
- a locking means (4) to close the cassette on the opposite side of the opening
(5) of the cassette;
Characterized in that the said locked device carrying the sample pellet is
placed in the chamber of spectrometer wherein sample pellet remain at
centre and infront of the aperture of the cassettes such that the ingress X-ray
spectrum through the aperture of the cassette may directly impinge on the
sample pallet for chemical analysis.

2. A device to hold a sample as claimed in claim 1 wherein the oxide materials
for spectroscopic analysis are slags, fluxes and raw materials in steel making.
3. A device as claimed in claim 1 wherein the plastic ring (6) being kept is
matching relationship with the steel ring (2) holding the sample pellet and the
extreme inner wall of the cassette (3), ensure the surface of the pressed
powder forming the pallet to be positioned at the central location of the
opening (5) of the cassette during analysis on closing the cassette.
4. A method for the said device as claimed in claim 1 to hold a sample pellet of
oxide materials for chemical analysis in XRF spectrometer comprising the
steps of

- inserting a plastic ring of 5 cm diameter and width amounting to the gap
between the steel ring holding the sample pellet formed on compression by
the steel ring of 4 cm diameter in a palletizing press,
- placing the sample pellet held in the steel ring in register relationship of its
outside surface to the inside surface of the plastic ring being supported by

the extreme inner wall of cassette, the exposed surface of the pellet being
maintained centrally on the opening of the cassette,
- closing the cassette at the opposite side of the opening of the cassette by a
press fit sliding locking means and
- placing the device so formed with the pellet in the sample chamber of the
spectrometer for chemical analysis of the oxide materials of the pellet.

5. A method for a device to hold a sample pellet as claimed in claim 4 wherin
the oxide materials for analysis are slag, flux and one materials involved is
steel making.
6. A method as claimed in claims 4 and 5 wherein the pellet is formed by
grounding as received lumps of the said materials to - 200 mesh powder,
pressing the powders into a pellet in a steel ring on compressing the powders
by the steel ring in a Herzog make pelletizing press.

7. A method for a device as claimed in claim 4 to 6 wherein the devices so
formed through securing any non-shiftment of the sample pellet during
analysis provide accurate chemical analysis of oxide materials and safeguard
process control activity during any steel making process.

ABSTRACT

A DEVICE TO HOLD A SAMPLE PELLET OF OXIDE MATERIALS FOR
CHEMICAL ANALYSIS IN XRF SPECTROMETER AND METHOD OF FORMING
THE DEVICE THEREOF
The present invention is provided with a device to hold a sample pellet of oxide
materials for chemical analysis in a XRF spectrometer comprising a plastic ring of 5
cm diameter and a width amounting to the gap between the steel ring (2) and the
inside wall of the cassette (3) being maintained in a register relationship with its
inside surface to the outside surface of the steel ring (2) and being supported by the
inner wall of the cassette (3); a locking means (4) to close the cassette on the
opposite side of the opening (5) of the cassette; Characterized in that the said
locked device carrying the sample pellet is placed in the chamber of spectrometer
wherein sample pellet remain at centre and infront of the aperture of the cassettes
such that the ingress X-ray spectrum through the aperture of the cassette may
directly impinge on the sample pallet for chemical analysis.