Title of Invention	THERMAL SHOCK RESISTANT MAGNESITE BRICKS AND A PROCESS FOR PREPARATION OF THERMAL SHOCK RESISTANT MAGNESITE BRICKS
Abstract	ABSTRACT The invention in general relates to a Tliermal Shock Resistant Magnesite Bricks and a process of preparation of thermal shock resistant magnesite bricks which can be used in steel making furnaces, cement rotary kilns, glass melting furnaces, non-ferrous metal production etc. This invention provide a controlled process of preparation of magnesite bricks with high thermal shock resistance under high operating temperature having no disposal problem and without any environmental hazards. This process of preparation of magnesite brick consists of preparation of Dead Burnt Magnesite powder(DBM), and mixing of said DBM with additives and binders like Magnesium Sulphate or Mono-Aluminium phosphate - commercial grades in the preferred ratios. The quality of Additives, Binders and Dead Burnt Magnesites are tested prior to mixing. The DBM peas are crushed and graded into fine fractions of powder in the closed Mill House circuit and thereafter drawn into the IMT Counter current mixer through the load cell where it is mixed with desired quantities of additives, binders and water for a fixed duration. Then the mix is then shaped into bricks with programmable Hydraulic Friction Screw Press and then the bricks are dried at 150*c in Kilns and preheated gradually and fired at high temperature in accordance with pre-determined firing profile and then cooled at 100 °c. Then the bricks are then subjected to physical tests in order to attain the required physical and mechanical properties. These bricks are widely used in the sintering transition zones of Cement rotary kiln.

Title of Invention

THERMAL SHOCK RESISTANT MAGNESITE BRICKS AND A PROCESS FOR PREPARATION OF THERMAL SHOCK RESISTANT MAGNESITE BRICKS

Abstract

ABSTRACT The invention in general relates to a Tliermal Shock Resistant Magnesite Bricks and a process of preparation of thermal shock resistant magnesite bricks which can be used in steel making furnaces, cement rotary kilns, glass melting furnaces, non-ferrous metal production etc. This invention provide a controlled process of preparation of magnesite bricks with high thermal shock resistance under high operating temperature having no disposal problem and without any environmental hazards. This process of preparation of magnesite brick consists of preparation of Dead Burnt Magnesite powder(DBM), and mixing of said DBM with additives and binders like Magnesium Sulphate or Mono-Aluminium phosphate - commercial grades in the preferred ratios. The quality of Additives, Binders and Dead Burnt Magnesites are tested prior to mixing. The DBM peas are crushed and graded into fine fractions of powder in the closed Mill House circuit and thereafter drawn into the IMT Counter current mixer through the load cell where it is mixed with desired quantities of additives, binders and water for a fixed duration. Then the mix is then shaped into bricks with programmable Hydraulic Friction Screw Press and then the bricks are dried at 150*c in Kilns and preheated gradually and fired at high temperature in accordance with pre-determined firing profile and then cooled at 100 °c. Then the bricks are then subjected to physical tests in order to attain the required physical and mechanical properties. These bricks are widely used in the sintering transition zones of Cement rotary kiln.

Full Text	This invention nefates to Thermal Stack Resistant Magnesite Bricks and to a process for preparation of Thermal Shock Resistant Magnesite Bricks. Background of the Invention In steel making furnaces, cement rotary Wins, glass melting furnaces, non-femDus nvatal production etc., magnesite based bricks are used. The advantages of nnagnestte based brick is its high nr^ting poinl^ excellent chemical resistant, and non-toxic nature. In the currently known art, the nruiin disadvantages of magnesite bricks in use, is low thermal shock resistance of magnesite bricks. Conventionally the know art for improving the thermal shock resistance of magnesite bricks refracturing additives have been used, like chrome are, alumina and spinel. The Chrome are additive to Magnesite bricks, definitely improves the thermal-shock resistance. But simultaneously it leads to disposal problem for the used bricks due to hexa-valent chrome formation, which In turn residts In environnoentai hazard. The Alumina or spinel additives to magnesots bricks aiso improve the thermal shock resistance, but it reacts with clinker melts and destroys the microstructure. Also the brides made using the alumina and spinet additives cannot be used in higher operating temperatures. Pbjf ct of th« Inwntfon Arcordlngly the object of the invention is to provide a magnesite brick with hygh thermal shock resi^ance. It is another object of the invention to provide a magnesite brick which can be used in high operating temperature. It is another object of the invention to provide a magnesite brick which has no dls\|x>sal problem for the used bricks. It Is another object of the invention to provide a Magnesite brickds, which do not create any environmental hazards. It is another object of the invention to pnovide a magnesite brick, which does not react with ciirri It is another objert of the invention, to resolve all the afbresaid disadvartoges in the prk>r art, addittonalty use of r^ractory additives is being eliminated, instead formulate cost effective high thermal shock resistant magnesite bricks using the Dead Burnt Magnesite (DBM) with sonne additives. In so ^r as said preferences are absent in the prior art, both the product of this invention and the hereinafter described pi^ocess for the same are novei. These and other objects of the invention will be apparent fnsm ensuing description. Main Advantaggff of the Invntion - Systematic Prxjcess for manufiKture of ensured high thermal shock resistant nnagnesibe bricks. Cost ^fective of the process. The Wgh thermal shock resistant magneslte bricks as per the Inventiony enable use in operating tenrperatures ranging from 120CPC to 175Cy>C. - Use of easily available and cheap Dead Bcrnt f4agnesite in the process. PiMriptiftn ftf tht invntwn According to the invention, the enhanced thermal shock resistance Is the unique characteristic of magnesite bricks origirtates from the controlled process which has been developed by the inventors. CONTROLLED PROCESS, SEQVENCE ft TIME PVRAnOW - Compo»tion of the ingredients decided by Statistical Design of Experiments. Quality of Additives, Binders and Dead Burnt Magnesits are tested prior to mixing. Dead Burnt Magnesitse peas is cru^ied and grwled in ttie dosed Niil Hou— circuit Dead Burnt MagnesitB Powder is produced and drawn fhxn Ring & Roller (^11 (in dosed circuit with air sei^arator etc.) Dead Burnt Magnesite - graded fractions &. fines are drawn thnaugh load ceii into 1 MT Counter Current Mixer with provision of intensive mixing, of Inorganic chemicals / Birxiers are added into definite proportions along with specified additive and mixed for a fixed duration with water and the brick mix is taken for pressing. The brick mix is pressed into bricks of definite shapes In programnrtable Hydraulic Friction Screw Press of 400 MT capacity at definite pressure te achieve uniform Bulk Density & Apparent Porosity. Green bricks kept in cars are dried at ISQoc arxJ pushed Into Shuttle Win, dried bricks are pre-heated gradually and fired at high tem\|3erature in accordance with pre-determined firing profile. After firing, the bricks are cooled into lOO^C inside the Shutbe Kiln and the cars are pushed out to unk>adlng area, where bricks are cooled down further. The brkics are subjected to various phystcat tests such as Af^xirent Porosity. Bulk Density, Thermal Shock Resistance Cycles (Air Quenching) Cold Crushing Strength, Cold Modulus of Rupture, Hot Modulus of Rupture, Thermal Conductivity, Refractoriness Under load, Pyrometric Cone Equivalent; aseel & Cement Raw Meal Reactivity tests. According to the invention, there is provided a process for the manufocture of thermal shock resistant magneslte bricks comprising :- a. preparing of Dead Burnt MagnesitB powder (OBM) (mm the peas b. collecting the DBM powder in a mixer. c. adding additives to DBM powder. d. adding ftirther bind^^ to the said mix. e. rraxing of content in the nrwxer by nrwans of agitator. f. Pressing the rrvx to achieve solid brick form g. drying of bricks at temperature 15CP h. firing the dried bricks in siuittie i. cooling the fired bricks j. further cooling the fired bricks until room temperature in an open area. The process is now described herein below in Its broadest scopes and aspects and the possit^ variant feature and characteristics of the invention are described alongwith equivalent feature and characteristics in the preferred embodiment TTie pr^erred embodiment is described therein below. A mixer of Dead Burnt Magneslte Powder, Magnesium Sulphate and Mono Aluminum Phosphate as binders and additives are used for preparing the high thermal shock nesistant magnesite bricks. A set sequence of preparing and nixing the said preferred ingredients thereof having been worked out for maximum effect in the prefemed embodiment as per invention. Said use of mixture in the said preparaljon of the said high thermal shock resistance n>agnesite bricks is a novel development as per Invention. PREFERREP PURATIQW Mil. Dead Bumt Magnesite Crushing &, Grinding 60 Addition of one Binder & curing 24 hrs Ackiitk>n of Ch^nicais & special Additivie 5 Mixing 10 Unloading & Packing of Brick l^ix 15 Transfer of Bride h«x to Press Bin 15 Pressing 10 Drying &. Bring &. Cooling 90 hrs (cycle) PREFERREP RATIO Range Dead Bumt Magnesite O-1 mm 24.5-26.5: 1-3 mm 33.0-3&0; 100% by weight 0-0.1mm 39.5-41.5: Magnesi um Sulphate 1.5% by weig ht Mono AiiNminimiffn Phosphate as% by weight Special Additive 1.0% by weight The invention is further illustrated by the preferred embodiment in the flow- diagram given in Rg. 1. However the scope of the invention is not limited by the said preferred enr>bodiment While several diffienent formulation can be used, the prefierned formulation is the use of Dead burr* Magnesite (DBM) and some additives and binders. \A^i(e several diffenant binders can be used, the pnefemad binders ana Magnesium Sulphate and Mono Aluminum Phosphate of commercial grades. Ingredients used for high thermal shock resistant magnesite bricks are :- a. Dead Bumt Magnesite b. Additive c. Anders (Magne^ivn Si;riphate and Mono Miurraraim Phosphate) - Connmercial Grades. Design of experiment technique is applied for the purpose of experiments in quality is to examine various factors that may influence the characteristics of some pnxJuct and confirm whether or not the selected factors do. In fact; have an effect and how large that eftect is. With design of experiments techniques, we can use statistics to predict and estimate restits b^sre we actually lnrH>l«ment a process. Design of experiments refiens to the methods used to determine - the type of experiment to be conducted how to analyze the data obtained in the experiment and the mininum ninnber of trials needed to produce the naquinad amount of information The best combination of aii the Ingredients and addition of water is carried out by Statistical Design of Experiment as per beiow : - Factors and Leveis of Experiment Factors, Levels and Design of Experinrtent Drawing Standanj Linear Graph Layout of Bcpedment ' Miystcal Layout of Experiment Deciding control parameters to be icept constant - Rnat response Carrying out ANOVA (Analysis of Variance) on test results and arriving the best combination • Carrying out conflrmatory tests on the b^t combination and freezing the composition The Design of Experiment technique gives the perfect combination of various ingredients to actirave the best results. Ttie k>est combination of alt ingredients and the process of mixing; pressing; and fifing are ait arrived by statistical design of experirY>ents. The product lias been illustrated in the flow diagram i.e. Rg - 1. Typical physical and mechanical properties of thermal shock resistant magnesite brick is: - Property Testing Specification Bulk Density, g/cc = Z92-3.05 IS 1528 Part XII Apparent poitasfty, % = 13-17 IS 1528 Part VHI Cold Crushing Strength, kg/cm2 = 450 (Min.) IS 1528 Part IV Cold Modulus of Rupture, Kg/cm2 =70 (Mfn.) IS 1528 Part V Themiai Shock resistance lOOOoq/air quencNng, Cydes =clO0(MtnL) IS 1528 Part HI Refractoriness Under Load (RUL), ta=16500C (MIn.) IS 1528 Part II Cement clinker Reactivity =good Cement Clinker penetration depth Newly developed brick =7.56 mm Method Designed by Inventors {tto Brick widely used in the Sintering IS is available) TransitkMTk zones of Cem^mt rotery =9.35mm Test procedure is iCin given below & In Api^endix-l Stgtl KWQ&ViVi = good Liquid Steel Penetration Depth Newly developed brick = 0.960 mm Method designed by inventors (No Carbon containing basic brick used IS is available) In the mental zone of Steel Ladle =a800 mm Test Procedure is given in Appendix-2 »T—tino Method for Cement ClinkT Reacth/ity : 50 mm diameter and 40 mm depth hole is drilled in the brick sample. 100 gnrts of calcinated raw meal Is mixed with 6 gms of coal ash. The mix Is filled In the cavity made In the brick The brick fs fired at 14500C for 30 mlnutiss and increase the temperature to ISOQOC for 30 minutes and altow to cool the brick in side the fiimac» itself. The fired raw meal Is removed from the cavity of the brick 100 gms of fiiesh calcinated raw meal mixed with 6 gms coal ash and filled In the cavity again. The fresh raw meal filled brick is fired again at 1450C for 30 nrtinubes and increase the temperature to ISOOK, for 30 minutes and allowed to cool the brick Inside the furnace. The fired raw meat is removed from the cavity of the brick again. lOOgms of fresh calcinated raw nneal mixed with 6 gms coal ash and filled in the cavity again. The fresh raw meal filled brick Is fired again at 1450^ for 30 minutes and increase the temperature to 1500'> C for 30 minutes and allowed to cool the brick inside the fimace. The fired raw nneal is renrxwed from the cavity of the brick again. After carrying out the firing exercise for three times every time filling the cavity with fresh calcinated raw meal+coal a^ n^xture, the brick was cut into two sections (horizontal & vertical) to find out the penetration depth or clinker in the brick using optical microscope. A clirrfoer naacti^nty test was carried out in id^itkal conditions using Oil Werfl Cement raw meal whit coal ash In the said newly developed brick and the brick widely used in the transition and sintering zone of cenrwnt rotary kiln. The clinker penetration depth (nrwn) was measured after the clinker reactivity test and reported herewith. APPENDIX - 2 »Tertlna Method for Steel Reacth^ity 50 mm diameter and 40 mm deep hole is drilled in the brick. 100 gms of steel turnings is filled in the hole and fired the brick in leCXPC for 3 hours. After firing and cooling down tD nsom temperature, the brick is removed fixim the furnace and cut into sections (horizontal & vertical) to find out the penetration depth of steel in the brick using optical microscope. A steel resistance test was carried in iderrtical conditions using steel turnings In the said newly developed brick and the carbon containing basic brick widely used in metal zone wear lining of steel ladle. The liquid steel penetration depth (mm) was measured after the steel reactivity test and reported herewith. The present invention provides a speedy formulated cost effective High TTTemnal Srock Resistant Magnesite Bricks and the process using the Dead Burnt Magnesite (DBM) which can be operated at high operating temperatures and overcoming all the disadvantages of prior art WE CLAIM : 1. A process for the preparation of thermal shock resistant magneslte bricks comprising o f following steps : preparing of Dead Burnt Magnesite powder (DBM) from the peas, collecting the DBM powder in a mixer, adding additives to DBM powder, adding binders to tiie said mix, mixing of content in tiie mixer by means of agitator, pressing the mix to achieve solid bricks form drying of bricks at temperature 15OP, firing the dried bricks in shuttle, cooling the fired bricks, and further cooling the fired bricks until room temperature in an open area. Z A thermal shock resistant Magnesite brick as claimed in claim 1, comprising of fbltowing ingredients : dead Burnt Magnesite, additives, and binders like Magnesium Sulphate and Mono-Aluminium Phosphate -Commercial Grades. 3. A themrwl shock resistant Magnesite brick as claimed in claim 1, having high thermal shock Le. temperature ranging from 12000C to 17500C. 4. A thermal shock nesistant Magnesite txick as claimed in claim 1, ha^^ng physical and mechanical properties as : a. Bulk Density, g/cc = Z92-3.05 IS 1528 Part XII b. Apparent porosity, % = 13-17 IS 1528 Part VIII c. Cold Crushing Strength, kg/cm2 = 450 (MIn.) IS 1528 Part IV d. Cold Modulus of Rupture, Kg/ariZ =70 (Min.) IS 1528 Part V e. Themnai Shock resistance f. lOOOoC/alr quenching. Cycles =100(Mln.) IS 1528 Part III g. Refractoriness Under Load (RUL), ta=1650oc (MIn.) IS 1528 Part II h. Cement Clinker penetration depth = 7.56 mm 9.35mm i. Liquid Steel Penetration Depth = 0.960 mm 0.800 mm 5. A process of pneparatk>n of thermal shock resistant Magnesite brick as claimed in Claim 1, wherein binders means Magnesium Sulphate & Mono Aluminium Phosphates. 6. A process for preparation of thermal shock resistant Magnesite bricks, substantiaUy as herein described. 7. A thermal shock resistant Magnesite brick, substantially as herein described.

Full Text

This invention nefates to Thermal Stack Resistant Magnesite Bricks and to a process for preparation of Thermal Shock Resistant Magnesite Bricks.
Background of the Invention
In steel making furnaces, cement rotary Wins, glass melting furnaces, non-femDus nvatal production etc., magnesite based bricks are used. The advantages of nnagnestte based brick is its high nr^ting poinl^ excellent chemical resistant, and non-toxic nature.
In the currently known art, the nruiin disadvantages of magnesite bricks in use, is low thermal shock resistance of magnesite bricks. Conventionally the know art for improving the thermal shock resistance of magnesite bricks refracturing additives have been used, like chrome are, alumina and spinel.
The Chrome are additive to Magnesite bricks, definitely improves the thermal-shock resistance. But simultaneously it leads to disposal problem for the used bricks due to hexa-valent chrome formation, which In turn residts In environnoentai hazard.
The Alumina or spinel additives to magnesots bricks aiso improve the thermal shock resistance, but it reacts with clinker melts and destroys the microstructure.

Also the brides made using the alumina and spinet additives cannot be used in higher operating temperatures.
Pbjf ct of th« Inwntfon
Arcordlngly the object of the invention is to provide a magnesite brick with hygh thermal shock resi^ance.
It is another object of the invention to provide a magnesite brick which can be used in high operating temperature.
It is another object of the invention to provide a magnesite brick which has no dls|x>sal problem for the used bricks.
It Is another object of the invention to provide a Magnesite brickds, which do not create any environmental hazards.
It is another object of the invention to pnovide a magnesite brick, which does not react with ciirri It is another objert of the invention, to resolve all the afbresaid disadvartoges in the prk>r art, addittonalty use of r^ractory additives is being eliminated, instead formulate cost effective high thermal shock resistant magnesite bricks using the Dead Burnt Magnesite (DBM) with sonne additives.

In so ^r as said preferences are absent in the prior art, both the product of this invention and the hereinafter described pi^ocess for the same are novei.
These and other objects of the invention will be apparent fnsm ensuing description.
Main Advantaggff of the Invntion
- Systematic Prxjcess for manufiKture of ensured high thermal shock resistant
nnagnesibe bricks.
Cost ^fective of the process.
The Wgh thermal shock resistant magneslte bricks as per the Inventiony
enable use in operating tenrperatures ranging from 120CPC to 175Cy>C.
- Use of easily available and cheap Dead Bcrnt f4agnesite in the process.
PiMriptiftn ftf tht invntwn
According to the invention, the enhanced thermal shock resistance Is the unique characteristic of magnesite bricks origirtates from the controlled process which has been developed by the inventors.
CONTROLLED PROCESS, SEQVENCE ft TIME PVRAnOW
- Compo»tion of the ingredients decided by Statistical Design of Experiments.

Quality of Additives, Binders and Dead Burnt Magnesits are tested prior to
mixing.
Dead Burnt Magnesitse peas is cru^ied and grwled in ttie dosed Niil Hou—
circuit
Dead Burnt MagnesitB Powder is produced and drawn fhxn Ring & Roller (^11
(in dosed circuit with air sei^arator etc.)
Dead Burnt Magnesite - graded fractions &. fines are drawn thnaugh load ceii
into 1 MT Counter Current Mixer with provision of intensive mixing, of
Inorganic chemicals / Birxiers are added into definite proportions along with
specified additive and mixed for a fixed duration with water and the brick mix
is taken for pressing.
The brick mix is pressed into bricks of definite shapes In programnrtable
Hydraulic Friction Screw Press of 400 MT capacity at definite pressure te
achieve uniform Bulk Density & Apparent Porosity.
Green bricks kept in cars are dried at ISQoc arxJ pushed Into Shuttle Win,
dried bricks are pre-heated gradually and fired at high tem|3erature in
accordance with pre-determined firing profile.
After firing, the bricks are cooled into lOO^C inside the Shutbe Kiln and the
cars are pushed out to unk>adlng area, where bricks are cooled down further.
The brkics are subjected to various phystcat tests such as Af^xirent Porosity.
Bulk Density, Thermal Shock Resistance Cycles (Air Quenching) Cold
Crushing Strength, Cold Modulus of Rupture, Hot Modulus of Rupture,
Thermal Conductivity, Refractoriness Under load, Pyrometric Cone
Equivalent; aseel & Cement Raw Meal Reactivity tests.

According to the invention, there is provided a process for the manufocture of thermal shock resistant magneslte bricks comprising :-
a. preparing of Dead Burnt MagnesitB powder (OBM) (mm the peas
b. collecting the DBM powder in a mixer.
c. adding additives to DBM powder.
d. adding ftirther bind^^ to the said mix.
e. rraxing of content in the nrwxer by nrwans of agitator.
f. Pressing the rrvx to achieve solid brick form
g. drying of bricks at temperature 15CP
h. firing the dried bricks in siuittie
i. cooling the fired bricks
j. further cooling the fired bricks until room temperature in an open area.
The process is now described herein below in Its broadest scopes and aspects and the possit^ variant feature and characteristics of the invention are described alongwith equivalent feature and characteristics in the preferred embodiment
TTie pr^erred embodiment is described therein below.
A mixer of Dead Burnt Magneslte Powder, Magnesium Sulphate and Mono Aluminum Phosphate as binders and additives are used for preparing the high thermal shock nesistant magnesite bricks. A set sequence of preparing and nixing the said preferred ingredients thereof having been worked out for maximum effect

in the prefemed embodiment as per invention. Said use of mixture in the said
preparaljon of the said high thermal shock resistance n>agnesite bricks is a novel
development as per Invention.
PREFERREP PURATIQW
Mil.
Dead Bumt Magnesite Crushing &, Grinding 60
Addition of one Binder & curing 24 hrs
Ackiitk>n of Ch^nicais & special Additivie 5
Mixing 10
Unloading & Packing of Brick l^ix 15
Transfer of Bride h«x to Press Bin 15
Pressing 10
Drying &. Bring &. Cooling 90 hrs (cycle)
PREFERREP RATIO
Range
Dead Bumt Magnesite O-1 mm 24.5-26.5:
1-3 mm 33.0-3&0; 100% by weight
0-0.1mm 39.5-41.5:
Magnesi um Sulphate 1.5% by weig ht
Mono AiiNminimiffn Phosphate as% by weight
Special Additive 1.0% by weight
The invention is further illustrated by the preferred embodiment in the flow-
diagram given in Rg. 1.

However the scope of the invention is not limited by the said preferred enr>bodiment
While several diffienent formulation can be used, the prefierned formulation is the use of Dead burr* Magnesite (DBM) and some additives and binders.
\A^i(e several diffenant binders can be used, the pnefemad binders ana Magnesium Sulphate and Mono Aluminum Phosphate of commercial grades.
Ingredients used for high thermal shock resistant magnesite bricks are :-
a. Dead Bumt Magnesite
b. Additive
c. Anders (Magne^ivn Si;riphate and Mono Miurraraim Phosphate) - Connmercial
Grades.
Design of experiment technique is applied for the purpose of experiments in quality is to examine various factors that may influence the characteristics of some pnxJuct and confirm whether or not the selected factors do. In fact; have an effect and how large that eftect is. With design of experiments techniques, we can use statistics to predict and estimate restits b^sre we actually lnrH>l«ment a process. Design of experiments refiens to the methods used to determine - the type of experiment to be conducted
how to analyze the data obtained in the experiment and

the mininum ninnber of trials needed to produce the naquinad amount of information
The best combination of aii the Ingredients and addition of water is carried out by Statistical Design of Experiment as per beiow : -
Factors and Leveis of Experiment
Factors, Levels and Design of Experinrtent
Drawing Standanj Linear Graph
Layout of Bcpedment ' Miystcal Layout of Experiment
Deciding control parameters to be icept constant - Rnat response
Carrying out ANOVA (Analysis of Variance) on test results and arriving the
best combination • Carrying out conflrmatory tests on the b^t combination and freezing the
composition
The Design of Experiment technique gives the perfect combination of various ingredients to actirave the best results. Ttie k>est combination of alt ingredients and the process of mixing; pressing; and fifing are ait arrived by statistical design of experirY>ents.
The product lias been illustrated in the flow diagram i.e. Rg - 1.

Typical physical and mechanical properties of thermal shock resistant magnesite brick is: -
Property Testing Specification
Bulk Density, g/cc = Z92-3.05 IS 1528 Part XII
Apparent poitasfty, % = 13-17 IS 1528 Part VHI
Cold Crushing Strength, kg/cm2 = 450 (Min.) IS 1528 Part IV
Cold Modulus of Rupture, Kg/cm2 =70 (Mfn.) IS 1528 Part V
Themiai Shock resistance
lOOOoq/air quencNng, Cydes =clO0(MtnL) IS 1528 Part HI
Refractoriness Under Load (RUL), ta=16500C (MIn.) IS 1528 Part II
*Cement clinker Reactivity =good
Cement Clinker penetration depth
Newly developed brick =7.56 mm Method Designed
by Inventors {tto
Brick widely used in the Sintering IS is available)
TransitkMTk zones of Cem^mt rotery =9.35mm Test procedure is
iCin given below & In
Api^endix-l
*Stgtl KWQ&ViVi = good
Liquid Steel Penetration Depth
Newly developed brick = 0.960 mm Method designed
by inventors (No
Carbon containing basic brick used IS is available)
In the mental zone of Steel Ladle =a800 mm Test Procedure is
given in Appendix-2

»T—tino Method for Cement ClinkT Reacth/ity :
50 mm diameter and 40 mm depth hole is drilled in the brick sample. 100 gnrts of calcinated raw meal Is mixed with 6 gms of coal ash. The mix Is filled In the cavity made In the brick The brick fs fired at 14500C for 30 mlnutiss and increase the temperature to ISOQOC for 30 minutes and altow to cool the brick in side the fiimac» itself. The fired raw meal Is removed from the cavity of the brick 100 gms of fiiesh calcinated raw meal mixed with 6 gms coal ash and filled In the cavity again. The fresh raw meal filled brick is fired again at 1450C for 30 nrtinubes and increase the temperature to ISOOK, for 30 minutes and allowed to cool the brick Inside the furnace. The fired raw meat is removed from the cavity of the brick again. lOOgms of fresh calcinated raw nneal mixed with 6 gms coal ash and filled in the cavity again. The fresh raw meal filled brick Is fired again at 1450^ for 30 minutes and increase the temperature to 1500'> C for 30 minutes and allowed to cool the brick inside the fimace. The fired raw nneal is renrxwed from the cavity of the brick again. After carrying out the firing exercise for three times every time filling the cavity with fresh calcinated raw meal+coal a^ n^xture, the brick was cut into two sections (horizontal & vertical) to find out the penetration depth or clinker in the brick using optical microscope.
A clirrfoer naacti^nty test was carried out in id^itkal conditions using Oil Werfl Cement raw meal whit coal ash In the said newly developed brick and the brick

widely used in the transition and sintering zone of cenrwnt rotary kiln. The clinker penetration depth (nrwn) was measured after the clinker reactivity test and reported herewith.
APPENDIX - 2
»Tertlna Method for Steel Reacth^ity
50 mm diameter and 40 mm deep hole is drilled in the brick. 100 gms of steel turnings is filled in the hole and fired the brick in leCXPC for 3 hours. After firing and cooling down tD nsom temperature, the brick is removed fixim the furnace and cut into sections (horizontal & vertical) to find out the penetration depth of steel in the brick using optical microscope.
A steel resistance test was carried in iderrtical conditions using steel turnings In the said newly developed brick and the carbon containing basic brick widely used in metal zone wear lining of steel ladle. The liquid steel penetration depth (mm) was measured after the steel reactivity test and reported herewith.
The present invention provides a speedy formulated cost effective High TTTemnal Srock Resistant Magnesite Bricks and the process using the Dead Burnt Magnesite (DBM) which can be operated at high operating temperatures and overcoming all the disadvantages of prior art

WE CLAIM :
1. A process for the preparation of thermal shock resistant magneslte bricks comprising o f following steps :
preparing of Dead Burnt Magnesite powder (DBM) from the peas,
collecting the DBM powder in a mixer,
adding additives to DBM powder,
adding binders to tiie said mix,
mixing of content in tiie mixer by means of agitator,
pressing the mix to achieve solid bricks form
drying of bricks at temperature 15OP,
firing the dried bricks in shuttle,
cooling the fired bricks, and
further cooling the fired bricks until room temperature in an open area.
Z A thermal shock resistant Magnesite brick as claimed in claim 1, comprising of
fbltowing ingredients :
dead Burnt Magnesite,
additives, and
binders like Magnesium Sulphate and Mono-Aluminium Phosphate -Commercial Grades.
3. A themrwl shock resistant Magnesite brick as claimed in claim 1, having high
thermal shock Le. temperature ranging from 12000C to 17500C.
4. A thermal shock nesistant Magnesite txick as claimed in claim 1, ha^^ng
physical and mechanical properties as :

a. Bulk Density, g/cc = Z92-3.05 IS 1528 Part XII
b. Apparent porosity, % = 13-17 IS 1528 Part VIII
c. Cold Crushing Strength, kg/cm2 = 450 (MIn.) IS 1528 Part IV
d. Cold Modulus of Rupture, Kg/ariZ =70 (Min.) IS 1528 Part V
e. Themnai Shock resistance
f. lOOOoC/alr quenching. Cycles =100(Mln.) IS 1528 Part III
g. Refractoriness Under Load (RUL), ta=1650oc (MIn.) IS 1528 Part II
h. Cement Clinker penetration depth = 7.56 mm 9.35mm
i. Liquid Steel Penetration Depth = 0.960 mm 0.800 mm
5. A process of pneparatk>n of thermal shock resistant Magnesite brick as
claimed in Claim 1, wherein binders means Magnesium Sulphate & Mono Aluminium
Phosphates.
6. A process for preparation of thermal shock resistant Magnesite bricks,
substantiaUy as herein described.
7. A thermal shock resistant Magnesite brick, substantially as herein described.

Documents:

0958-mas-1999 abstract.pdf

0958-mas-1999 claims duplicate.pdf

0958-mas-1999 claims.pdf

0958-mas-1999 correspondence-others.pdf

0958-mas-1999 correspondence-po.pdf

0958-mas-1999 description (complete) duplicate.pdf

0958-mas-1999 description (complete).pdf

0958-mas-1999 drawings duplicate.pdf

0958-mas-1999 drawings.pdf

0958-mas-1999 form-1.pdf

0958-mas-1999 form-13.pdf

0958-mas-1999 form-19.pdf

0958-mas-1999 form-26.pdf

0958-mas-1999 form-5.pdf

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Patent Number

196412

Indian Patent Application Number

958/MAS/1999

PG Journal Number

30/2009

Publication Date

24-Jul-2009

Grant Date

23-Jan-2006

Date of Filing

29-Sep-1999

Name of Patentee

M/S. DALMIA MAGNESITE CORPORATION

Applicant Address

SALEM 636 012

Inventors:

#	Inventor's Name	Inventor's Address
1	JAI HARI DALMIA	NESALEM - 636 012
2	SRINIVASA VEERA RAGHAVAN	SALEM - 636 012

PCT International Classification Number

C04B7/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA