Title of Invention

A PROCESS FOR MANUFACTURING BILENDED CEMENT USING FERRO CHROME SLAG

Abstract This invention relates to a process for manufacturing blended cement using ferro -chrome slag comprising the following sequential steps of g) screening of granulated ferro chrome slag at 10 mm; h) rejecting the +10 mm fraction of ferro chrome slag; i) screening of- 10 mm fraction of ferro chrome elag at 3 mm; j) crushing the + 3 mm fraction of ferro chrome slag to - 3 mm; k) the -3 mm fraction is subjected to two magnetic separation at 2000 to 2500 gauss; 1) the non - magnetic fraction upto 40% is blended with ordinary Portland Cement by separate grinding of the clinker (with gypsum) to fineness of 450 and 305 m2/kg respectively and blending them uniformly; the binary blends of ferro chrome slag and ordinary Portland Cement being tested for their physical and chemical properties to meet IS specification.
Full Text The invention relates to a process for manufacturing blended cement using ferro chrome slag.
At present steel plant slag particularly blast furnace slag is being utilised for the manufacture of slag cement and which conforms to Indian Standards as specified for slag cement.
The ferro chrome slag produced particularly at Fe-Cr plant hitherto has never been used for manufacture of
blended cement. In fact, there was no use of this slag.
50,000 tpa On an average a medium size/ Fe-Cr plant produces about
54,000 tpa of slag.After granulating the slag is disposed off as a waste. Due to ecological problems created by disposal of this slag and limitation of dumping space, its proper utilisation has become a great concern.
The disadvantages associated with the ferro-chrome slag for utilising in the manufacture of blended cement is that the slag contains metal which is as high as 5 wt.%.
Therefore the main object of the present invention Us to propose a process for separating the metal from ferro Chrome slag and using the remaining slag in making blended cements.
Another object of the present invention is to propose a process for manufacturing blended cements utilising ferro-chrome slag which leads to the utilisation of 70-. 75% of the waste. This would eliminate the space cscniitfed for* dumping the slag and the consequential environmental problem by 70-75%.
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Further object of the present invention is to propose a process for manufacturing blended cement utilising ferro - chrome slag which h will meet the Indian Standard at low cost and shall meet the ever increasing demand of the country.
According to the present invention there is provided a process for manufacturing blended cement using ferro-chrome slag comprising the following steps;
a) screening of granulated ferro chrome slag at 10 mm;
b) reject +10 mm ferro chrome slag;
c) screening of-10 mm ferro chrome slag at 3 mm;
d) crushing the+ 3 mm ferro chrome slag to -3 mm;
e) The - 3 mm fraction is subjected to two stage magnetic separation at 2000
to 2500 gauss;
f) The non - magnetic fraction upto 40% is blended with ordinary Portland
Cement by separate grinding of the clinker (with gypsum) to fineness of
450 and 305 m2/Kg respectively and blending them uniformly;
binary blends of ferro chrome slag and ordinary Portland Cement being tested for their physical and chemical properties to meet IS specification. The nature of the invention, its objective and further advantages residing in the same will be apparent from the following description made with reference to non - limiting exemplary embodiments of the invention represented in the accompanying drawings.
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Figure 1 - Flow sheet for removal of metal from granulated slag.
In accordance with the present invention the process details for manufacturing of blended
cement using ferro - chrome slag is given below.
Figure 1 shows a flow chart of the detailed process steps.
(i) Hie ferro chrome slag is granulated at 4 Kg/cm3 minimum water pressure.
(ii) The granulated slag is then screened at 10 mm.
(iii) Hie +10 mm which forms 5 wt % is rejected The - 10 mm fraction (granulated
slag) which is 95 wt% and 9.2% Cr and 4.1% Fe is again screened at 3 mm. The
coarser + 3 mm fraction again being crushed to -3 mm and recycled and screened
at 3 mm. (iv) Hie - 3 mm fraction is subjected to first stage magnetic separation at 2000-2500
gauss for metal removal and magnetic (I) material is rejected, (v) Hie non - magnetic (I) fraction is again subjected to second stage magnetic
separation. Hie first and second stage magnetic (I & II) material which comprised
20.7 wt % and 16.7 Cr % and 6:9 Fe % is rejected (vi) Hie non - magnetic (II) fraction (comprising 74.3 wt % and 7.0S Cr % and 1.6 Fe
%) is blended with ordinary Portland Cement by separate grinding of the clinker
(with gypsum) and slag upto 40% to the fineness of 450 and 305 m2 / Kg
respectively and blending them uniformly, (vii) Binary blends of ferro chrome slag and ordinary Portland Cement (FS-4- & FS-5)
are tested for their physical and chemical properties. Details of physical
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and chemical properties of cement blends are shown below.
SAMPLE

PROPERTIES

FS4

FS5

SPECIFICATION OF PORTLAND
SLAG CEMENT (IS:455)



BLENDED COMPOSITION

(%)
OPC 75 60
Fe-Cr Slag 25 40
CHEMICAL
COMPOSITION, %
LOI 2.5 2.5
CaO 47.2 38.3
SO^ 1 .70 1 .70
IR 9-3 15.8
MgO 7.4 10.2
S 0 .09 0.07
PHYSICAL PROPERTIES
387
Fineness, (rn^/kg) 389 Setting Time(min)

ajlnitial setting 140 time 120
b) Final setting 185 time 170
compressive Strength (Mpa)
ai) 3 days 34.7 29.2
bi) 7 days 42.5 34.3
i c) 28 days 53.3 49.6


5 max.
3 max
4 max
8 max
1 . .5 max
> 225
>; 30

>16
>22
>33

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The invention described hereinabove is in re^tion to a non - limiting embodiment and as defined by the accompanying claims.
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WE CLAIM
A process for manufacturing blended cement using ferro - chrome slag comprising the following sequential steps of
a) screening of granulated ferro chrome slag at 10 mm;
b) rejecting the +10 mm fraction of ferro chrome slag;
c) screening of-10 mm fraction of ferro chrome slag at 3 mm;
d) crushing the + 3 mm fraction of ferro chrome slag to - 3 mm;
e) the -3 mm fraction is subjected to two magnetic separation at 2000 to 2500 gauss;
f) the non - magnetic fraction upto 40% is blended with ordinary Portland Cement
by separate grinding of the clinker (with gypsum) to fineness of 450 and 305
nvVkg respectively and blending them uniformly; the binary blends of ferro
chrome slag and ordinary Portland Cement being tested for their physical and
chemical properties to meet IS specification.

2. A process for manufacturing blended cement using ferro-chrome slag as claimed
in claim 1 wherein the ferro chrome slag is granulated at 4 Kg minimum water
pressure and screened at 10 mm and 5 wt % is rejected as +10 mm.
3. A process for manufacturing blended cement using ferro-chrome slag as claimed
in claim 2 wherein - 10 mm fraction of 95 wt%, comprising 9.2 Cr% and 4.1
Fe% is further screened at 3mm and - 3mm fraction is subjected to two stage
magnetic separation at 2000 - 2500 gauss for metal removal.
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4. A process for manufacturing blended cement using ferro-chrome slag as claimed
in claim 3 wherein the final non-magnetic separation comprises 74.3 wt %.
5. A process for manufacturing blended cement using ferro chrome Blag as herein
described and illustrated
This invention relates to a process for manufacturing blended cement using ferro -chrome slag comprising the following sequential steps of
g) screening of granulated ferro chrome slag at 10 mm;
h) rejecting the +10 mm fraction of ferro chrome slag;
i) screening of- 10 mm fraction of ferro chrome elag at 3 mm;
j) crushing the + 3 mm fraction of ferro chrome slag to - 3 mm;
k) the -3 mm fraction is subjected to two magnetic separation at 2000 to 2500 gauss;
1) the non - magnetic fraction upto 40% is blended with ordinary Portland Cement by separate grinding of the clinker (with gypsum) to fineness of 450 and 305 m2/kg respectively and blending them uniformly; the binary blends of ferro chrome slag and ordinary Portland Cement being tested for their physical and chemical properties to meet IS specification.

Documents:

00046-cal-1999 abstract.pdf

00046-cal-1999 claims.pdf

00046-cal-1999 correspondence.pdf

00046-cal-1999 description (complete).pdf

00046-cal-1999 drawings.pdf

00046-cal-1999 form-1.pdf

00046-cal-1999 form-18.pdf

00046-cal-1999 form-2.pdf

00046-cal-1999 form-3.pdf

00046-cal-1999 letters patent.pdf

00046-cal-1999 p.a.pdf


Patent Number 201225
Indian Patent Application Number 46/CAL/1999
PG Journal Number 09/2007
Publication Date 02-Mar-2007
Grant Date 02-Mar-2007
Date of Filing 20-Jan-1999
Name of Patentee P V TAYAR RAO
Applicant Address TATA IRON & STEEL CO.LTD., RESEARCH AND DEVLOP.DIV. JAMSHEDPUR 831001
Inventors:
# Inventor's Name Inventor's Address
1 P V TAYAR RAO TATA IRON & STEEL CO.LTD., RESEARCH AND DEVLOP.DIV. JAMSHEDPUR 831001
2 TAYAR RAO TATA IRON & STEEL CO.LTD., RESEARCH AND DEVLOP.DIV. JAMSHEDPUR 831001
3 KAMAL CHANDRA PIPLAI TATA IRON & STEEL CO.LTD., RESEARCH AND DEVLOP.DIV. JAMSHEDPUR 831001
4 SARI PALLI MOHAN RAO TATA IRON & STEEL CO.LTD., RESEARCH AND DEVLOP.DIV. JAMSHEDPUR 831001
5 MRS.SONAL ARORA TATA IRON & STEEL CO.LTD., RESEARCH AND DEVLOP.DIV. JAMSHEDPUR 831001
PCT International Classification Number C04B28/04
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA