Title of Invention	A PROCESS FOR DETERMINATION OF COAL CHAR REACTIVITY AND COAL CHAR STRENGTH AFTER REDUCTION IN A SMELTING REDUCTION IRON MAKING PROCESS.
Abstract	A process for determination of Coal Char Reactivity Index (CCRI) arid Coal Char Strength After Reduction (CCSR) directed to favour deciding on the suitability of coal for processes especially the Corex process, smelting reduction iron making process and Finex process. Importantly, the above process would favour simulating and giving an understanding of the condition such as reactivity of coal char near tuyeres, strength and permeability of coal char. Thus, the invention is directed to the development of much desired test procedure which can simulate the coal char reactivity and its strength after reaction near tuyeres of Corex and Finex processes for effective and proper utilization of such processes where melter-gasifier function is involved.

Title of Invention

A PROCESS FOR DETERMINATION OF COAL CHAR REACTIVITY AND COAL CHAR STRENGTH AFTER REDUCTION IN A SMELTING REDUCTION IRON MAKING PROCESS.

Abstract

A process for determination of Coal Char Reactivity Index (CCRI) arid Coal Char Strength After Reduction (CCSR) directed to favour deciding on the suitability of coal for processes especially the Corex process, smelting reduction iron making process and Finex process. Importantly, the above process would favour simulating and giving an understanding of the condition such as reactivity of coal char near tuyeres, strength and permeability of coal char. Thus, the invention is directed to the development of much desired test procedure which can simulate the coal char reactivity and its strength after reaction near tuyeres of Corex and Finex processes for effective and proper utilization of such processes where melter-gasifier function is involved.

Full Text	FORM 2 THE PATENT ACT 1970 (39 OF 1970) & The Patent Rules, 2003 COMPLETE SPECIFICATION (See Section 10 and Rule 13) 1 TITLE OF THE INVENTION : A PROCESS FOR DETERMINATION OF COAL CHAR REACTIVITY AND COAL CHAR STRENGTH AFTER REDUCTION IN A SMELTING REDUCTION IRON MAKING PROCESS. 2 APPLICANT (S) Name : JSW Steel Limited. Nationality : An Indian Company. Address : Jindal Mansion, 5-A, Dr. G. Deshmukh Marg ,Mumbai State of Maharastra, India. - 400 026, 3 PREAMBLE TO THE DESCRIPTION COMPLETE The following specification particularly descibes the invention and the manner in be performed. which it is to Field of the invention The present invention relates to processes for smelting reduction iron making processes and in particular to a process for determination of Coal Char Reactivity Index (CCRI) and Coal Char Strength After Reduction (CCSR) which favour deciding on the suitability of coal for such processes including the Corex process, smelting reduction iron making process and Finex process. Importantly, the above process of the invention would provide simulating and giving an understanding of the condition such as reactivity of coal char near tuyeres, strength and permeability of coal char. Thus, the invention would favours the development of much desired test procedure which can simulate the coal char reactivity and its strength after reaction near tuyeres of Corex and Finex processes where melter-gasifier function is involved. BACKGROUND ART It is known in the art that Corex is a smelting reduction iron making process developed as an alternative to Blast Furnace (BF) .Such Corex process usually consist of two reactors (i) the reduction shaft and (ii) the melter gasifier. It is also well known that in Corex process, non coking coal is used for heat generation, production of reducing gases and to maintain adequate bed permeability unlike in Blast Furnace (BF) where coke meets such requirements. Thus, the non coking coals which can be used in Corex have to meet physical, chemical and high temperature properties for stable process and to attain high performance levels. Importantly, it is also observed during years of Corex operation that high temperature properties of coal play a major role for stable performance. It is also known that the development of the Corex process also provided procedures to test the high temperature properties of coal such as thermal decrepitation and thermo mechanical stability. The thermal decrepitation test measures the grain preservation index (+ 10 mm), and dust generation index (- 2mm) of coal during rapid heating condition in the melter - gasifier, which simulates the dome conditions. The thermo mechanical stability determines the strength of char found after devolatilization of coal in the char bed of melter - gasifier. Both the above tests however only simulate the condition and behaviour of coal in the melter gasifier dome and in the fixed char bed. The 2 behavior of coal char formed after devolatilization in dome and fixed bed in front of the tuyeres could not be determined with the above tests. Importantly, similar to coke ,CSR and CRI, the coal char reactivity and strength after reaction, are a major concern, as these play a major role in the formation of stable char beds. However, in the absence of any such method to determine char reactivity and its strength after reaction, no effective process of determining such coal char reactivity and strength after reaction was possible which in turn affected the possibility of understanding the reaction process in Corex. Moreover, the absence of any manner of determination of coal char reactivity and strength after reaction which are a major concern in the formation of stable char bed, there had been a continuing problem to effectively decide on the suitability of the coal for such processes including the Corex, Finex processes which involve melter - gasifier functions. Moreover, the absence of such tests procedure also make it extremely difficult to understand related conditions of such process such as the reactivity of coal char near tuyeres, strength and permeability to the coal char. Also, such limitations in carrying out the Corex or Finex processes involving such melter -gasifier functions also, lead to concerns which affect optimizing the coal blend and the stabilization of the processes especially such as the Corex or Finex process. OBJECTS OF THE INVENTION It is thus the basic object of the present invention to provide a process for simple yet effective determination of coal char reactivity index and coal char strength after reaction which would favour effective and proper utilization of processes such as the Corex or Finex process involving melter gasifier functions. Another object of the present invention is directed to provide for better efficacy and utilization of Corex process where non-coking coal is used for heat generation, production of reducing gases and to maintain adequate bed permeability by providing for meeting physical, chemical and high temperature properties for stable process and to attain high performance levels. Another objects of the present invention is directed to facilitate smelting reduction iron making processes such as Corex, Finex were the high temperature properties of coal is known to play a major role for stable performance. 3 Yet another objects of the present invention is directed to avoid the limitations of presently available methods of simulation of the conditions and behavior of coal in the melter-gasifier dome and in the fixed char bed and provide for processes for determination of behavior of coal char (formed after devolatalization in dome and fixed bed) in front of the tuyeres and thereby favour the iron making processes such as Corex and Finex. A further objects of the present invention is directed to a process for simulating coal char reactivity and its strength after reaction near tuyeres of Corex melter-gasifier. Another objects of the present invention is provided to favour iron making processes by making available decisions on suitability of Corex process. A further objects of the present invention is directed to achieve optimization of coal blend and stabilization and improvement in efficiency of Corex process and Finex process where melter - gasifier functions are involved. SUMMARY OF THE INVENTION Thus according to the basic aspect of the present invention there is provided a process for determination of coal char reactivity comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C in N2 atmosphere under selective flow rate; after attaining the desired temperature the N2 flow is suspended and the sample reacted with C02 at a desired flow rate for a defined period; after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at desired flow rate till the sample reaches a temperature of the weighed sample is next tumbled and selectively screened and recorded; and obtaining the Coal Char Reactivity Index (CCRI) based on 4 (Initial wt of the sample - wt of the sample after reaction with CO2) X 100 CCRI = ( Initial wt of the sample) In accordance with a preferred aspect of the present invention there is provided a process for determination of coal char reactivity comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C preferably 1100 °C in N2 atmosphere with a flow rate in the range of 200 to 400 Iph; after attaining the 1100°C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.; after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow arte of 200 to 400 Iph; preferably 300 lph till the sample reaches a temperature of the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and obtaining the Coal Char Reactivity Index (CCRI) based on (Initial wt of the sample - wt of the sample after reaction with CO2) X 100 CCRI = ( Initial wt of the sample) In accordance with yet another aspect of the present invention there is provided a process for determination of coal char strength after reaction comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C in an inert atmosphere with a desired flow rate; after attaining the said temperature the inert flow is suspended and the sample reacted with C02 at desired flow rate for a defined period.; after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in inert atmosphere at desired flow rate till the sample reaches a temperature of 5 the weighed sample is next tumbled and selectively screened and recorded; and obtaining the Coal Char Strength after Reaction (CCSR) based on the following: (Wt. of +10mm sample) x 100 CCSR= (wt of the sample after reaction with C02) According to a further preferred aspect of the invention there is provided a process for determination of coal char strength after reaction comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C preferably 1100 °C in N2 atmosphere with a flow rate in the range of 200 to 400 Iph; after attaining the 1100 °C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 Iph preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.; after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow arte of 200 to 400 Iph preferably 300lph till the sample reaches a temperature of the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and obtaining the Coal Char Strength after Reaction (CCSR) based on the following: (Wt, of +10mm sample) x 100 CCSR = (wt of the sample after reaction with C02) In the above disclosed processes of the invention for determining the CCRI and CCRS process as above the said step of providing coal char sample comprises: screening of non coking coal samples in the range of 20-25 mm; soaking a representative sample at a temperature in the range of 800 to 1200°C for a period of 30 to 90 min. in an inert atmosphere to remove the VM; 6 cooling the representative sample in an inert atmosphere to a temperature of less than 200°C; further screening of the sample and preparation of the coal char therefrom. The said coal char is prepared involving a Coal Decrepitation apparatus. Preferably, the char sample comprises of 19-21 mm size char having Thus according to a further aspect of the invention there is provided a smelting reduction iron making process involving melter-gasifier functions comprising the steps of: determination of coal char reactivity and/or determination of coal char strength after reaction as discussed above. Such a smelting reduction iron making process involving such simulated determination of coal char reactivity and coal char strength can selectively comprise Corex and Finex processes. Advantageously, in the above smelting reduction iron making processes the coal bed can be optimized and the process stabilized based on the determined simulated CCSR and CCRI values of various coals and selective provision of coal blends and optimization of the iron making process and make it more user friendly and cost-effective. It is thus possible by way of the present invention to facilitate iron making processes such Corex and Finex processes by way of procedures to simulate the coal char reactivity and its strength after reaction near tuyeres of melter - gasifier used in such processes. Importantly, the process of the invention would favour decisions on suitability of coal for such Corex and Finex processes. Importantly, the test procedures of the invention would favour simulating and understanding of conditions such as reactivity of coal char near tuyeres, strength and permeability of coal char. Advantageously, the above processes for the determination of coal char reactivity index and coal char strength after reaction of various coals and in the process enable optimization of coal blend stabilization of the iron 7 making processes in particular, the Corex and Finex processes where melter - gasifier functions are involved. Also the above disclosed process for determination of coal char reactivity index and coal char strength after reaction would facilitate improving the performance of the Corex or Finex processes by way of favouring determination of behavior of coal char (formed after devolatalization in dome and fixed bed) in front of the tuyeres which was not possible under the known procedures to test high temperature properties of coal such as thermal decrepitation and thermo mechanical stability. The details of the invention, its objects and advantages are explained hereunder in greater detail in relation to non-limiting exemplary illustration of the process for determination of coal char reactivity index and coal char strength after reaction in accordance with the present invention. EXAMPLES : Example 1: Under this example, the preparation of the coal char for testing the coal char reactivity index and coal char strength after reaction in accordance with the present invention was carried out as follows:- The gross sample was collected from yard and screened to 20-25 mm and 500 g of representative sample was taken for the test; the representative sample was next soaked at a temperature of 1000° C for a period 1h in an inert atmosphere (N2) to remove the VM; the representative sample was next cooled in an inert atmosphere to a temperature of about 80°C; the representative sample was next screened at 19-21 mm; and Coal decrepitation apparatus was used for the preparation of coal char as above. 8 Example 2: Under this example, the test procedure for determining the coal char reactivity index and coal char strength after reaction in accordance with the invention was carried out as detailed hereunder:- 200 g of 19-21 mm size char sample having after reaching 1100°C, the N2 flow was suspended and sample reacted with C02 at flow rate of about 300 Iph for 120 min.; after 120 min., the C02 flow was suspended and the sample cooled in N2 atmosphere at a flow rate of about 300 Iph till the sample reached to a temperature the sample was next weighed and the weight recorded. The sample was tumbled in a tumbler drum of size about 130mm dia, 700mm length for 600 rev at 20 rpm; the tumbled sample was screened at 10mm and wt. pf +10mm & -10mm was recorded; the Coal Char Reactivity Index (CCRI) and Coal Char Strength after Reaction (CCSR) was calculated as follows: CCRI _ (Initial wt of the sample - wt of the sample after reaction with CO2) X 100 ( Initial wt of the sample) CCSR _ (Wt. of +10mm sample) x 100 (wt of the sample after reaction with C02) In accordance with an embodiment, the dimensions of the CO gas generator retort which is used for CCRI & CCSR determination include dimensions such as Length: 750 - 900 mm;Intemal Diameter: 90 - 124 mm and Plate thickness: 5-10 mm. Following the above process of the invention, the CCRI % and CCRS % of variety of coals were determined as indicated in the following Table I: TABLE I Coal A B C CCSR, % 60 47 35 CCRI, % 24 34 40 9 Based on the above identified CCRI % and CCRS % of the above variety of coals Coal A, Coal B and Coal C ,it was possible to formulate different coal blends and further studies were carried out to ascertain the Corex performance and its dependency based on the coal blend CCRS%. For such purpose the following coal blends involving the above Coal grades A,B and C were obtained as per the Examples D,E and F as further detailed under Table II hereunder: TABLE II Coal Blend Coal Blend D E F Coal A, % 15 10 10 Coal B, % 45 40 30 Coal C, % 40 50 60 Blend CCSR, % 45 43 41.5 The Corex performance of the above Coal Blends were noted and the results are noted hereunder in Table III: TABLE III Corex Performance Parameters Coal Blend D E F Production rate, t/hr 105 103 102 Fuel rate, kg/thm 943 1037 1053 It would be clearly apparent from the above that selective use of coal blends with high CCSR resulted in superior performance of Corex. It is thus possible by way of the present invention to determine the suitability of coal for Corex process. Advantageously, the process of the invention would simulate and provide for the much required understanding of the conditions, such as reactivity of coal char near tuyeres, strength, and permeability of coal char. As illustrated by way of the present invention, the CCSR and CCRI values of various coals obtained from the tests detailed above would favour optimizing the coal blend and stabilize the Corex process. Importantly, the invention demonstrates that the use of blend with high CCSR resulted in much desired superior performance of Corex. As also discussed hereinbefore the above process of the invention is applicable also to Finex process, where the melter-gasifier function is same as in Corex. 10 Advantageously, the invention would avoid the limitations of presently available method of simulation of the conditions and behavior of coal in the melter-gasifier dome and in the fixed char bed and provide for processes for determination of behavior of coal char (formed after devolatalization in dome and fixed bed) in front of the tuyeres and thereby favour the iron making processes such as Corex and Finex. Thus the present invention would provide the required process for simple yet effective determination of coal char reactivity index and coal char strength after reaction which would favour effective and proper utilization of processes such as the Corex or Finex process involving melter gasifier functions. Importantly also the invention would favour better efficacy and utilization of Corex process where non-coking coal is used for heat generation, production of reducing gases and to maintain adequate bed permeability by providing for meeting physical, chemical and high temperature properties for stable process and to attain high performance levels. 11 We Claim: 1. A process for determination of coal char reactivity comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950 to 1250°C in N2 atmosphere under selective flow rate; after attaining the desired temperature the N2 flow is suspended and the sample reacted with C02 at a desired flow rate for a defined period; after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at desired flow rate till the sample reaches a temperature of the weighed sample is next tumbled and selectively screened and recorded; and obtaining the Coal Char Reactivity Index (CCRI) based on (Initial wt of the sample - wt of the sample after reaction with CO2) X 100 CCRI = ( Initial wt of the sample) 2. A process for determination of coal char reactivity comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950 to 1250°C preferably 1100 °C in N2 atmosphere with a flow rate in the range of 200 to 400 Iph; after attaining the 1100°C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 Iph preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.; after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow rate of 200 to 400 Iph preferably 300 lph till the sample reaches a temperature of 12 the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and obtaining the Coal Char Reactivity Index (CCRI) based on (Initial wt of the sample - wt of the sample after reaction with CQ2) X 100 CCRI = ( Initial wt of the sample) 3. A process for determination of coal char strength after reaction comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950 to 1250°C in an inert atmosphere with a desired flow rate; after attaining the said temperature the inert flow is suspended and the sample reacted with C02 at desired flow rate for a defined period.; after said reaction for the desired period with C02/ the C02 flow is suspended and the sample cooled in inert atmosphere at desired flow rate till the sample reaches a temperature of the weighed sample is next tumbled and selectively screened and recorded; and obtaining the Coal Char Strength after Reaction (CCSR) based on the following: (Wt. of +10mm sampled X100 CCSR = (wt of the sample after reaction with C02) 4. A process for determination of coal char strength after reaction comprising: providing coal char sample; subjecting the coal char sample to heating in the temperature range of 950 to 1250°C preferably 1100 °C in l\l2 atmosphere with a flow rate in the range of 200 to 400 Iph; after attaining the 1100°C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 Iph preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.; 13 after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow rate of 200 to 400 Iph preferably 300lph till the sample reaches a temperature of the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and obtaining the Coal Char Strength after Reaction (CCSR) based on the following: (Wt. of +10mm sample) x 100 CCSR = (wt of the sample after reaction with C02) 5. A process as claimed in anyone of claims 1 to 4 wherein said step of providing cola char sample comprises: screening of non coking coal samples in the range of 20-25 mm; soaking a representative sample at a temperature in the range of 800 to 1200 °C for a period of 30 to 90 min. in an inert atmosphere to remove the VM; cooling the representative sample in an inert atmosphere to a temperature less than 200°C; further screening of the sample and preparation of the coal char therefrom. 6. A process as claimed in claim 5 wherein said coal char is prepared involving a Coal Decrepitation apparatus. 7. A process as claimed in anyone of claims 1 to 6 wherein the char sample comprises of 19-21 mm size char having 8. A process as claimed in anyone of claims 1 to 7 wherein the sample is tumbled in a tumbler drum. 14 9. A smelting reduction iron making process involving melter-gasifier functions comprising the steps of: determination of coal char reactivity and/or determination of coal char strength after reaction as claimed in anyone of claims 1 to 8. 10. A smelting reduction iron making process as claimed in claim 9 wherein the smelting reduction iron making process is selected from Corex and Finex process. 11. A smelting reduction iron making process as claimed in anyone of claims 9 or 10 wherein coal bed is optimized and the process stabilized based on the CCSR and CCRI values of various coals. 12. A process for simulation of coal char reactivity, a process for simulation of coal char strength after reaction and a smelting reduction iron making process involving such process of simulation of coal char reactivity and coal char strength substantially as here in described and illustrated with reference to the accompanying examples. Dated this 6th day of August, 2007 Anjan Sen Of Anjan Sen & Associates (Applicants Agent) 15 ABSTRACT A PROCESS FOR DETERMINATION OF COAL CHAR REACTIVITY AND COAL CHAR STRENGTH AFTER REDUCTION IN A SMELTING REDUCTION IRON MAKING PROCESS. A process for determination of Coal Char Reactivity Index (CCRI) arid Coal Char Strength After Reduction (CCSR) directed to favour deciding on the suitability of coal for processes especially the Corex process, smelting reduction iron making process and Finex process. Importantly, the above process would favour simulating and giving an understanding of the condition such as reactivity of coal char near tuyeres, strength and permeability of coal char. Thus, the invention is directed to the development of much desired test procedure which can simulate the coal char reactivity and its strength after reaction near tuyeres of Corex and Finex processes for effective and proper utilization of such processes where melter-gasifier function is involved. 16

Full Text

FORM 2 THE PATENT ACT 1970 (39 OF 1970) & The Patent Rules, 2003 COMPLETE SPECIFICATION (See Section 10 and Rule 13)
1 TITLE OF THE INVENTION :
A PROCESS FOR DETERMINATION OF COAL CHAR REACTIVITY AND COAL CHAR STRENGTH AFTER REDUCTION IN A SMELTING REDUCTION IRON MAKING PROCESS.
2 APPLICANT (S)
Name : JSW Steel Limited.
Nationality : An Indian Company.
Address : Jindal Mansion, 5-A, Dr. G. Deshmukh Marg ,Mumbai State of Maharastra, India. - 400 026,
3 PREAMBLE TO THE DESCRIPTION
COMPLETE
The following specification particularly descibes the invention and the manner in be performed. which it is to

Field of the invention
The present invention relates to processes for smelting reduction iron making processes and in particular to a process for determination of Coal Char Reactivity Index (CCRI) and Coal Char Strength After Reduction (CCSR) which favour deciding on the suitability of coal for such processes including the Corex process, smelting reduction iron making process and Finex process. Importantly, the above process of the invention would provide simulating and giving an understanding of the condition such as reactivity of coal char near tuyeres, strength and permeability of coal char. Thus, the invention would favours the development of much desired test procedure which can simulate the coal char reactivity and its strength after reaction near tuyeres of Corex and Finex processes where melter-gasifier function is involved.
BACKGROUND ART
It is known in the art that Corex is a smelting reduction iron making process developed as an alternative to Blast Furnace (BF) .Such Corex process usually consist of two reactors (i) the reduction shaft and (ii) the melter gasifier. It is also well known that in Corex process, non coking coal is used for heat generation, production of reducing gases and to maintain adequate bed permeability unlike in Blast Furnace (BF) where coke meets such requirements.
Thus, the non coking coals which can be used in Corex have to meet physical, chemical and high temperature properties for stable process and to attain high performance levels. Importantly, it is also observed during years of Corex operation that high temperature properties of coal play a major role for stable performance.
It is also known that the development of the Corex process also provided procedures to test the high temperature properties of coal such as thermal decrepitation and thermo mechanical stability. The thermal decrepitation test measures the grain preservation index (+ 10 mm), and dust generation index (- 2mm) of coal during rapid heating condition in the melter - gasifier, which simulates the dome conditions.
The thermo mechanical stability determines the strength of char found after devolatilization of coal in the char bed of melter - gasifier. Both the above tests however only simulate the condition and behaviour of coal in the melter gasifier dome and in the fixed char bed. The
2

behavior of coal char formed after devolatilization in dome and fixed bed in front of the tuyeres could not be determined with the above tests.
Importantly, similar to coke ,CSR and CRI, the coal char reactivity and strength after reaction, are a major concern, as these play a major role in the formation of stable char beds. However, in the absence of any such method to determine char reactivity and its strength after reaction, no effective process of determining such coal char reactivity and strength after reaction was possible which in turn affected the possibility of understanding the reaction process in Corex.
Moreover, the absence of any manner of determination of coal char reactivity and strength after reaction which are a major concern in the formation of stable char bed, there had been a continuing problem to effectively decide on the suitability of the coal for such processes including the Corex, Finex processes which involve melter - gasifier functions. Moreover, the absence of such tests procedure also make it extremely difficult to understand related conditions of such process such as the reactivity of coal char near tuyeres, strength and permeability to the coal char. Also, such limitations in carrying out the Corex or Finex processes involving such melter -gasifier functions also, lead to concerns which affect optimizing the coal blend and the stabilization of the processes especially such as the Corex or Finex process.
OBJECTS OF THE INVENTION
It is thus the basic object of the present invention to provide a process for simple yet effective determination of coal char reactivity index and coal char strength after reaction which would favour effective and proper utilization of processes such as the Corex or Finex process involving melter gasifier functions.
Another object of the present invention is directed to provide for better efficacy and utilization of Corex process where non-coking coal is used for heat generation, production of reducing gases and to maintain adequate bed permeability by providing for meeting physical, chemical and high temperature properties for stable process and to attain high performance levels.
Another objects of the present invention is directed to facilitate smelting reduction iron making processes such as Corex, Finex were the high temperature properties of coal is known to play a major role for stable performance.
3

Yet another objects of the present invention is directed to avoid the limitations of presently available methods of simulation of the conditions and behavior of coal in the melter-gasifier dome and in the fixed char bed and provide for processes for determination of behavior of coal char (formed after devolatalization in dome and fixed bed) in front of the tuyeres and thereby favour the iron making processes such as Corex and Finex.
A further objects of the present invention is directed to a process for simulating coal char reactivity and its strength after reaction near tuyeres of Corex melter-gasifier.
Another objects of the present invention is provided to favour iron making processes by making available decisions on suitability of Corex process.
A further objects of the present invention is directed to achieve optimization of coal blend and stabilization and improvement in efficiency of Corex process and Finex process where melter - gasifier functions are involved.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention there is provided a process for determination of coal char reactivity comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C in N2 atmosphere under selective flow rate;
after attaining the desired temperature the N2 flow is suspended and the sample reacted with C02 at a desired flow rate for a defined period;
after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at desired flow rate till the sample reaches a temperature of the weighed sample is next tumbled and selectively screened and recorded; and obtaining the Coal Char Reactivity Index (CCRI) based on
4

(Initial wt of the sample - wt of the sample after reaction with CO2) X 100
CCRI = ( Initial wt of the sample)
In accordance with a preferred aspect of the present invention there is provided a process for determination of coal char reactivity comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C preferably 1100 °C in N2 atmosphere with a flow rate in the range of 200 to 400 Iph;
after attaining the 1100°C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.;
after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow arte of 200 to 400 Iph; preferably 300 lph till the sample reaches a temperature of the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and
obtaining the Coal Char Reactivity Index (CCRI) based on
(Initial wt of the sample - wt of the sample after reaction with CO2) X 100
CCRI = ( Initial wt of the sample)
In accordance with yet another aspect of the present invention there is provided a process for determination of coal char strength after reaction comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C
in an inert atmosphere with a desired flow rate;
after attaining the said temperature the inert flow is suspended and the sample reacted with C02 at desired flow rate for a defined period.;
after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in inert atmosphere at desired flow rate till the sample reaches a temperature of 5

the weighed sample is next tumbled and selectively screened and recorded; and obtaining the Coal Char Strength after Reaction (CCSR) based on the following:
(Wt. of +10mm sample) x 100
CCSR= (wt of the sample after reaction with C02)
According to a further preferred aspect of the invention there is provided a process for determination of coal char strength after reaction comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950°C to 1250°C preferably 1100 °C in N2 atmosphere with a flow rate in the range of 200 to 400 Iph; after attaining the 1100 °C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 Iph preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.;
after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow arte of 200 to 400 Iph preferably 300lph till the sample reaches a temperature of the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and
obtaining the Coal Char Strength after Reaction (CCSR) based on the following:
(Wt, of +10mm sample) x 100
CCSR = (wt of the sample after reaction with C02)
In the above disclosed processes of the invention for determining the CCRI and CCRS process as above the said step of providing coal char sample comprises:
screening of non coking coal samples in the range of 20-25 mm;
soaking a representative sample at a temperature in the range of 800 to 1200°C for a period of 30 to 90 min. in an inert atmosphere to remove the VM;
6

cooling the representative sample in an inert atmosphere to a temperature of less than 200°C;
further screening of the sample and preparation of the coal char therefrom. The said coal char is prepared involving a Coal Decrepitation apparatus.
Preferably, the char sample comprises of 19-21 mm size char having Thus according to a further aspect of the invention there is provided a smelting reduction iron making process involving melter-gasifier functions comprising the steps of:
determination of coal char reactivity and/or determination of coal char strength after reaction as discussed above.
Such a smelting reduction iron making process involving such simulated determination of coal char reactivity and coal char strength can selectively comprise Corex and Finex processes.
Advantageously, in the above smelting reduction iron making processes the coal bed can be optimized and the process stabilized based on the determined simulated CCSR and CCRI values of various coals and selective provision of coal blends and optimization of the iron making process and make it more user friendly and cost-effective.
It is thus possible by way of the present invention to facilitate iron making processes such Corex and Finex processes by way of procedures to simulate the coal char reactivity and its strength after reaction near tuyeres of melter - gasifier used in such processes.
Importantly, the process of the invention would favour decisions on suitability of coal for such Corex and Finex processes. Importantly, the test procedures of the invention would favour simulating and understanding of conditions such as reactivity of coal char near tuyeres, strength and permeability of coal char. Advantageously, the above processes for the determination of coal char reactivity index and coal char strength after reaction of various coals and in the process enable optimization of coal blend stabilization of the iron
7

making processes in particular, the Corex and Finex processes where melter - gasifier functions are involved.
Also the above disclosed process for determination of coal char reactivity index and coal char strength after reaction would facilitate improving the performance of the Corex or Finex processes by way of favouring determination of behavior of coal char (formed after devolatalization in dome and fixed bed) in front of the tuyeres which was not possible under the known procedures to test high temperature properties of coal such as thermal decrepitation and thermo mechanical stability.
The details of the invention, its objects and advantages are explained hereunder in greater detail in relation to non-limiting exemplary illustration of the process for determination of coal char reactivity index and coal char strength after reaction in accordance with the present invention.
EXAMPLES : Example 1:
Under this example, the preparation of the coal char for testing the coal char reactivity index and coal char strength after reaction in accordance with the present invention was carried out as follows:-
The gross sample was collected from yard and screened to 20-25 mm and 500 g of representative sample was taken for the test;
the representative sample was next soaked at a temperature of 1000° C for a period 1h in an inert atmosphere (N2) to remove the VM;
the representative sample was next cooled in an inert atmosphere to a temperature of about 80°C;
the representative sample was next screened at 19-21 mm; and
Coal decrepitation apparatus was used for the preparation of coal char as above.
8

Example 2:
Under this example, the test procedure for determining the coal char reactivity index and coal char strength after reaction in accordance with the invention was carried out as detailed hereunder:-
200 g of 19-21 mm size char sample having after reaching 1100°C, the N2 flow was suspended and sample reacted with C02 at flow rate of about 300 Iph for 120 min.;
after 120 min., the C02 flow was suspended and the sample cooled in N2 atmosphere at a flow rate of about 300 Iph till the sample reached to a temperature the sample was next weighed and the weight recorded. The sample was tumbled in a tumbler drum of size about 130mm dia, 700mm length for 600 rev at 20 rpm;
the tumbled sample was screened at 10mm and wt. pf +10mm & -10mm was recorded;
the Coal Char Reactivity Index (CCRI) and Coal Char Strength after Reaction (CCSR) was calculated as follows:
CCRI _ (Initial wt of the sample - wt of the sample after reaction with CO2) X 100
( Initial wt of the sample)
CCSR _ (Wt. of +10mm sample) x 100
(wt of the sample after reaction with C02)
In accordance with an embodiment, the dimensions of the CO gas generator retort which is used for CCRI & CCSR determination include dimensions such as Length: 750 - 900 mm;Intemal Diameter: 90 - 124 mm and Plate thickness: 5-10 mm.
Following the above process of the invention, the CCRI % and CCRS % of variety of coals were determined as indicated in the following Table I:
TABLE I
Coal A B C
CCSR, % 60 47 35
CCRI, % 24 34 40
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Based on the above identified CCRI % and CCRS % of the above variety of coals Coal A, Coal B and Coal C ,it was possible to formulate different coal blends and further studies were carried out to ascertain the Corex performance and its dependency based on the coal blend CCRS%. For such purpose the following coal blends involving the above Coal grades A,B and C were obtained as per the Examples D,E and F as further detailed under Table II hereunder:
TABLE II
Coal Blend
Coal Blend D E F
Coal A, % 15 10 10
Coal B, % 45 40 30
Coal C, % 40 50 60
Blend CCSR, % 45 43 41.5
The Corex performance of the above Coal Blends were noted and the results are noted hereunder in Table III:
TABLE III

Corex Performance Parameters
Coal Blend D E F
Production rate, t/hr 105 103 102
Fuel rate, kg/thm 943 1037 1053
It would be clearly apparent from the above that selective use of coal blends with high CCSR resulted in superior performance of Corex.
It is thus possible by way of the present invention to determine the suitability of coal for Corex process. Advantageously, the process of the invention would simulate and provide for the much required understanding of the conditions, such as reactivity of coal char near tuyeres, strength, and permeability of coal char.
As illustrated by way of the present invention, the CCSR and CCRI values of various coals obtained from the tests detailed above would favour optimizing the coal blend and stabilize the Corex process. Importantly, the invention demonstrates that the use of blend with high CCSR resulted in much desired superior performance of Corex. As also discussed hereinbefore the above process of the invention is applicable also to Finex process, where the melter-gasifier function is same as in Corex.
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Advantageously, the invention would avoid the limitations of presently available method of simulation of the conditions and behavior of coal in the melter-gasifier dome and in the fixed char bed and provide for processes for determination of behavior of coal char (formed after devolatalization in dome and fixed bed) in front of the tuyeres and thereby favour the iron making processes such as Corex and Finex.
Thus the present invention would provide the required process for simple yet effective determination of coal char reactivity index and coal char strength after reaction which would favour effective and proper utilization of processes such as the Corex or Finex process involving melter gasifier functions. Importantly also the invention would favour better efficacy and utilization of Corex process where non-coking coal is used for heat generation, production of reducing gases and to maintain adequate bed permeability by providing for meeting physical, chemical and high temperature properties for stable process and to attain high performance levels.
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We Claim:
1. A process for determination of coal char reactivity comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950 to 1250°C in N2 atmosphere under selective flow rate;
after attaining the desired temperature the N2 flow is suspended and the sample reacted with C02 at a desired flow rate for a defined period;
after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at desired flow rate till the sample reaches a temperature of the weighed sample is next tumbled and selectively screened and recorded; and
obtaining the Coal Char Reactivity Index (CCRI) based on
(Initial wt of the sample - wt of the sample after reaction with CO2) X 100
CCRI = ( Initial wt of the sample)
2. A process for determination of coal char reactivity comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950 to 1250°C preferably 1100 °C in N2 atmosphere with a flow rate in the range of 200 to 400 Iph;
after attaining the 1100°C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 Iph preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.;
after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow rate of 200 to 400 Iph preferably 300 lph till the sample reaches a temperature of 12

the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and
obtaining the Coal Char Reactivity Index (CCRI) based on
(Initial wt of the sample - wt of the sample after reaction with CQ2) X 100
CCRI = ( Initial wt of the sample)
3. A process for determination of coal char strength after reaction comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950 to 1250°C in an inert atmosphere with a desired flow rate;
after attaining the said temperature the inert flow is suspended and the sample reacted with C02 at desired flow rate for a defined period.;
after said reaction for the desired period with C02/ the C02 flow is suspended and the sample cooled in inert atmosphere at desired flow rate till the sample reaches a temperature of the weighed sample is next tumbled and selectively screened and recorded; and
obtaining the Coal Char Strength after Reaction (CCSR) based on the following:
(Wt. of +10mm sampled X100
CCSR = (wt of the sample after reaction with C02)
4. A process for determination of coal char strength after reaction comprising:
providing coal char sample;
subjecting the coal char sample to heating in the temperature range of 950 to 1250°C preferably 1100 °C in l\l2 atmosphere with a flow rate in the range of 200 to 400 Iph;
after attaining the 1100°C the N2 flow is suspended and the sample reacted with C02 at a flow rate of 200 to 400 Iph preferably 300 Iph for a period of 90 to 150 min. preferably 120 min.;
13

after said reaction for the desired period with C02, the C02 flow is suspended and the sample cooled in N2 atmosphere at flow rate of 200 to 400 Iph preferably 300lph till the sample reaches a temperature of the weighed sample is next tumbled and screened at 10mm and wt. of +10 mm & -10 mm recorded; and
obtaining the Coal Char Strength after Reaction (CCSR) based on the following:
(Wt. of +10mm sample) x 100
CCSR = (wt of the sample after reaction with C02)
5. A process as claimed in anyone of claims 1 to 4 wherein said step of providing cola
char sample comprises:
screening of non coking coal samples in the range of 20-25 mm;
soaking a representative sample at a temperature in the range of 800 to 1200 °C for a period of 30 to 90 min. in an inert atmosphere to remove the VM;
cooling the representative sample in an inert atmosphere to a temperature less than 200°C;
further screening of the sample and preparation of the coal char therefrom.
6. A process as claimed in claim 5 wherein said coal char is prepared involving a Coal Decrepitation apparatus.
7. A process as claimed in anyone of claims 1 to 6 wherein the char sample comprises of 19-21 mm size char having 8. A process as claimed in anyone of claims 1 to 7 wherein the sample is tumbled in a tumbler drum.
14

9. A smelting reduction iron making process involving melter-gasifier functions
comprising the steps of:
determination of coal char reactivity and/or determination of coal char strength after reaction as claimed in anyone of claims 1 to 8.
10. A smelting reduction iron making process as claimed in claim 9 wherein the smelting reduction iron making process is selected from Corex and Finex process.
11. A smelting reduction iron making process as claimed in anyone of claims 9 or 10 wherein coal bed is optimized and the process stabilized based on the CCSR and CCRI values of various coals.
12. A process for simulation of coal char reactivity, a process for simulation of coal char strength after reaction and a smelting reduction iron making process involving such process of simulation of coal char reactivity and coal char strength substantially as here in described and illustrated with reference to the accompanying examples.
Dated this 6th day of August, 2007 Anjan Sen
Of Anjan Sen & Associates (Applicants Agent)
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ABSTRACT
A PROCESS FOR DETERMINATION OF COAL CHAR REACTIVITY AND COAL CHAR STRENGTH AFTER REDUCTION IN A SMELTING REDUCTION IRON MAKING PROCESS.
A process for determination of Coal Char Reactivity Index (CCRI) arid Coal Char Strength After Reduction (CCSR) directed to favour deciding on the suitability of coal for processes especially the Corex process, smelting reduction iron making process and Finex process. Importantly, the above process would favour simulating and giving an understanding of the condition such as reactivity of coal char near tuyeres, strength and permeability of coal char. Thus, the invention is directed to the development of much desired test procedure which can simulate the coal char reactivity and its strength after reaction near tuyeres of Corex and Finex processes for effective and proper utilization of such processes where melter-gasifier function is involved.
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Patent Number

269056

Indian Patent Application Number

1538/MUM/2007

PG Journal Number

40/2015

Publication Date

02-Oct-2015

Grant Date

29-Sep-2015

Date of Filing

08-Aug-2007

Name of Patentee

JSW STEEL LIMITED

Applicant Address

JINDAL MANSION, 5-A,DR.G.DESHMUKH MARG, MUMBAI

Inventors:

#	Inventor's Name	Inventor's Address
1	PEDDOLLA PRACHETHAN KUMAR	JSW STEEL LIMITED, R&D AND SS, VIDYANAGER, TORANAGULLU, BELLARY-583275
2	BOYALLA MASTAN REDDY	JSW STEEL LIMITED, R&D AND SS, VIDYANAGER, TORANAGULLU, BELLARY-583275
3	KODAL THIMMANA SHARANA GOUDA	JSW STEEL LIMITED, R&D AND SS, VIDYANAGER, TORANAGULLU, BELLARY-583275
4	RANJAN MADHU	JSW STEEL LIMITED, R&D AND SS, VIDYANAGER, TORANAGULLU, BELLARY-583275

PCT International Classification Number

C21B11/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA