Title of Invention

"METHOD FOR MANUFACTURING CEMENT CLINKER"

Abstract A process and apparatus by which blast-furnace slag can be added to the feedstock materials fed into the feed-end of a rotary cement kiln to form cement clinkers. The blast-furnace slag is crushed and screened to provide blast-furnace slag particles having particles with a predominant size of up to a maximum diameter of substantially 2" or less.
Full Text 1. FILED OF THE INVENTION
This invention relates in general internal if to the manufacturing of cement clinker in long rotary kilns. In particular, the invention relates to the method and apparatus for the manufacture of cement clinker in conventional long; wet or dry rotary kilns wherein blast-furnace slag is added at the input-end of kiln with a stream of feedstock material containing lime such (hat as (the stream of feedstock and blast-furnace slag moves toward the heat at the heat-end of the kiln, the blast-furnace slag is melted and defused into the feedstock material to form cement clinkers.
2. ST ATE: OF THE: AR I
As stated in U.S. Patent No. 5.156,676, the htetature is replete with processes by which the calcining and clinkering of cement ingredicms". can he accomplished. The typical process using a rotary kiln. either wet or dry. is well known. Cement raw materials such as limestone, clay and sand, or the like, are finely ground and intimately mixed to provide ;. substantially homogeneous mixture at the input or feed-end of the kiln. the kiln is tipped dowiiuardly at an angle such that the heat-end of the kiln is below the feed-end. The kiln has generally lour operating zones including a proclaiming zone, a calcining /one, a clinkering zone., and a cooling zone. Conventional fuel is combined with preheated air and injected into the Li'n at the he- it end. Fuels such as natural gas, oil of powdered coad are conventionally) employed in cement manufacturing processes.
A-. the finely divided cement raw materials pass into the rotating, kiln at tne feed-end thereof, the material, are heated from neal ambient temperature to about .5380C' (10000F) in the proclaiming zone., in this zone, the heat of the combustion gases from the calcining /one is used to raise the temperature of the raw materials. Additionally, in the kihi. chain systems or the like may be attached :o the interior ol the kiln and aic employed to improve the efficiency of heat exchange between the gases and raw materials.
The temperature of the raw materials is increased from about :5380C to about 10930C (1000°F to about .20000I) as they pass through the calcining zone and in this zone CaCO. is decomposed with the evolution of CO,.
Calcined material at the temperature of about 1093°C (2000°F) (hen [passes into the clinkering or burning zone when, the temperature is raised to about 15000C (2732°F). It is in this zone that the primary raw material are converted into the typical cement compounds such as tricalciam ilicate
dicalcium silicate, tricalcunn ahminato, and tctracalcium-aluininolerrite. The cement clinker:- then leave the clinuering zone where the clinkers are cooled and thereafter processed further such as by grinding.
Further, the use of ground blast-furnace slag as a cementitious material dates back to 1774. In the production of iron, the blast furnace is continuously charged from the top with iron oxide sources, fluxing stone, and fuel. Two products are obtained from the furnace: molten iron that collects in the bottom of the furnace and liquid iron blast-furnace slag floating on the pool of iron. Both are periodically tapped from the furnace at a temperature of about 1500°C (2732°F). The slag consists primarily of silica and alumina combined with calcium and magnesium oxides from the fluxing stone. Cementitious activity of this slag for use in mortar or concrete is determined by its composition and the rate at which the molten material is cooled when it comes from the furnace.
Further, in the production of steel, a similar process occurs wherein liquid steel slag floats on the pool of steel. Again, the steel slag consists primarily of silica and alumina combined with calcium and magnesium oxides. Disposing of both the steel slag and the blast-furnace slag poses a major disposal problem for the manufactuier thereof because ol the amount ol materials involved.
Both the steel slag and the blast-furnace slag is composed of particles that are very hard. The blast-furnace slag, when used, has always been in a finely powdered or granulated form, which means that a great deal of energy must be used to grind and pulverize the slag into the finely powdered form or to granulate it. Such a process is disclosed in U.S. Patent 2,600,515 in which a blast-furnace slag, in a finely powdered mixture with limestone, is fed in rotary cement kilns and is infoducrd directly into the flame of the kiln. The slag powder i; blown in at the same time and by the- same channels as the fuel,
namely, pulverized coal, heavy oil or gas. 1 his process has several
disadvantages. One of the most signilicant disadvantages is that enormous
amounts of energy are requiled to pulverize and dry the matenal so thai il
could be blown into the furnace.
Many of the chemical compounds, in steel :,lag and blast-furnace slag are
common to cement chemical compounds and their heat of formation is already
been accomplished in their respective processes. The American Concrete
Institute defines blast-fuinace slay as follows:
blast-furnace slag — the nonmetallic product, consisting essentially of silicates and alunu'nosilicates of calcium and other bases, that is developed in a molten condition simultaneously with iron in a blast furnace.
1. '.air-cooled blast-furnace slag is the material resulting
from solidification of molten blast-furnace slag under
atmospheric conditions: subsequent cooling may be
accelerared by application of water to the solidified
storage
2. expanded blast-furnace slag is the lightweight,
cellular material obtained by controlled processing of
molten blast-furnace slag with water, or water and other
agents, such as steam or compressed ai:, or both.
3 granulated blast-furnace slag is the glassy, granular material formed when molten biast-iurnace slag is rapidly chilled, as by immersion in water.
In the present case, the term "blast-furnace slag" will be used hereafter to designate only "air-cooled blast-furnace slag" and not expanded or granulated blast-furnace slag unless otherwise stated.
These products, with the addition of Ca(.)14, can be converted to 3CaO SiO2 (C3S), 2CaO • SiO, (C,S). 2CaO Fo,(,vC2F), 4CaO A1,O, Fe2O3(C4AF), 3CaO A12O,(C3A) in the burning zone of the rotary kiln.
Experience has shown blasl-furnace slag has no deleterious effect on the operation of a cement rotary kiln. Amission ot volatile materials from the rotary kiln is improved because the slag has previously been heat Heated and most volatile materials have been removed, i.e. carbon dioxide, catbon, volatile organics, and the like. However, as stated in the prior art, fine grinding or comminution or pulverization of the- slag is required, thus adding an expensive step to the cement-making process. Also, granulated slag is also very expensive to form.
SUMMARY OF THE INVENTION
Because it has long been recognized that many of the chemiels and chemical compounds in blast-furnace slag are common to cement making materials and because blast-furnace slag is available in large quantities, it would be advantageous to be able to use the blast-furnace slag in the cement-making process if it could be used in a much coarser state than the pulverized or granulated state now required and if it could be added to the feedstock materials being fed to the kiln at the feed-end of the kiln instead of the heat-end thereof.
The present invention provides such use of blast-furnace slag and provides a method and apparatus for utilization of various blast-furnace process slags that have been crushed and screened to provide a coarse state with a predominant particle size having diameters up to 2" with the coarse blast-furnace slag being fed into the input-end of the kiln with the feedstock materials, thereby obtaining all of the advantages of the prior art use of blastfurnace slag without the disadvantage of the requirements to provide granulation of the slag or fine grinding, pulverizing or comminution of" the slag and introducing the fine blast-furnace slag into the heat-end of the kiln.
As stated previously, Applicant's experience has shown blast-furnace slag to have no deleterious effect on the operation of a cement rotary kiln. Emission of volatile materials from the rotary kiln is improved because the blast-furnace slag has previously been heat-treated and most volatile materials have been removed, i.e. carbon dioxide, carbon, volatile organics, and the like. Because of the previous history of the blast-furnace slag, the required blastfurnace slag cheinistn,' has already been achieved during the steel making process thus conserving erevgv in the iron-making process. Thus there are a number of advantages of lthe of his slag united as stated earlier. no fine
grinding, pulverizing or comminution of the slag is lequined. Large quantities of coarse slag (defined herein as blast-furnace siag having predominant particle sizes that are substantially up to in diameter can be incorporated into the cement clinker composition with only minor chemical changes to the regulat material feed to the rotary kiln. causing and screening is required only for slag panicles m access of 2 in diameter.
second. no drying of the, slag is equired, inherent moisture normally runs %to 050. in the wet process rotary kiln system, substantial moisture reduction and .savings are realized. In the dry piocess rotary kiln system, it is not required thai the blast-furnace siag be dried.
Third, no plugging of the kiln has been experienced due to mud ring or clinker buildup. In both the wet and the dry process rotary kilns, the coarse blast-furnace slag has a cleaning effect on material buildup as it moves through the kiln.
Fourth, the coarse blast-furnace slag can be utilized as part of the initial feedstock and is introduced into the kiln at the feed-end thereof. The blastfurnace slag and wet or dry feed.Mock may be injected into the feed-end of the rotary kiln as separate materials and may be injected together at the feed-end of the kiln without prior blending,.
Fifth, only slight chemical changes in the feedstock composition are required for the normal feedstock to accommodate the blast-furnace slag. This usually means the feedstock must be richer in lime content.
Six, the coarse blast-furnace slag chemical compound structure transforms to the desired cement clinker structure during, the heal treatment within the rotary kiln by diffusion.
Seventh, substantial energy savings are realated when the blag lumer slag is utilized because of the low temperature at which the blast-furnace .SLAG
melts and because no grinding or pulverizing of the blast-furnace slag is required.
Eight, cement clinker production increases are almost propotional to the amount of blast-furnace slag united.
Ninth, the environmental condition of the totary kiln process improves because of the low volatile content oi the blast lurnace slag.
Tenth, recycling of the blast-furnace slag improves the environment because it provides an important use for the lags quanties of blast-furance slag available and avoids any so-called problems with disposal of the blastfurnace slag.
Eleventh, the cost of cement production is substantially reduced because of the energy savings, and the plentiful supply ol low cost blast-furnace slag.
Thus, it is an object to the present invention to provide an improved method and apparatus for operating a rotary kiln for the production of cement clinker using coarse blast-lumance slag, a by-product of the iron-making processes.
Ii is another object to the present invention to introduce the coarse blastfurnace slag into " cement- totly kiln at the feed-end thereof.
It is still another object of the present invention to use coarse blastfurnace slag having predominant practile sizes that are substantially 2" in diameter or .
1 Thus the present invention relates to a method of cement clinker manufacture using an elongated totlycement kiln having a feed-end and a heat-end, the heat-end being lilted downwardly with respect to the feed-end, the method comprising the steps of directing heat from a heat source into the hear-end of the kiln, introducing a person of feedstock mateial containing iime into the feed-end of the that the stream of feedstock material moves toward the heat at the and adding a predected mired
amount of crushed and screened b;ast furanace slag to the stream of feedstock material at the feed-end of the kiln such that as the stream of feedstock material and blast-furnace slag merges toward the heat-end of the kiln, the blast-furnace slag is melted by the that and dilfused into the feedstock material to form cement clinkers
The invention also relates to apparatus for forming cement clinkers comprising a rotary cement kiln having a feed-end and a heat-end, the heat-end being tilted downwardly with respect to the leed-end, a heat source: at the heat-end for heating the interior of the rotary kiln, and conveying means for introducing a stream of feedstock material containing lime and blast-furnace slag into the feed-end of the rotary kiln such that as the stream of feedstock material and blast-furnace slag move toward the heat-end of the kiln, the blastfurnace slag is diffused by the heal into the feedstock material to form cement clinker.
Accordingly the present invention relates to a method of manufacturing cement clinker using an elongated rotary cement kiln having a feed-end and a heat-end, the heat-end being tilted downwardly with respect to the feed-end, the method comprising the steps of: directing heat from a heat source into said heat-end of the kiln; introducing a stream of feedstock material containing lime into said
feed-end of the kiln such that the stream of feedstock material moves toward said heat at the heat-end of the kiln; crushing and screening air-cooled blast-furnace slag to obtain particles with a
predominant size of up to a maximum diameter of substantially 2"; and adding an amount of said crushed and screened air-cooled blast-furnace slag to said stream of feedstock material at said feed-end of the kiln, such that as the stream of feedstock material and blast-furnace slag moves toward said heat-end, the blast-furnace slag is melted by said heat and diffused into the feedstock material to form cement clinkers.
BRIEF DESCRIPTION OF THE DRAWINGS?
These and other more detailed objects of the present invention will be more fully disclosed in the following DETAILED DESCRIPTION OF THE DRAWINGS in which:
FIG. 1 is a basic diagrammatic representation of a rotary kiln system of the present invention for forming cement clinkers in which the feedstock material and the blastfurnace slag are fed together into the input-end of the rotary kilns;
FIG. 2 is a diagrammatic representation of the feedstock material and the blastfurnace slag being feed separately into the inlet-end of the rotary kiln.
FIG. 3 is a flow chart representation of the process in which the feedstock material and the blast-furnace slag are fed into the input-end of the kiln in a combined mixture; and
FIG. 4 is a flow chart representation of an alternate process in which the feedstock material and the blast-furnace slag are fed separately into the input or feed-end of the rotary kiln.

: DETAILED DESCRIPTION OF THE DRAWINGS
The present invention allows crushed and screened raw blast lurnance slag to be added to the kiln feed as a separate component at the feed-end of the rotary cement kiln in various parcle sizes wherein the predominant particle size is up to a maximum of 2" in diameter. The term "raw" blast-furnace slat;, as used herein, means blast-furnace slag that is unprocessed in any manner except for crushing and screening of the blast-furnace-slag that is in a solid state. Most blast-furnace slay has particles below 2" in diameter. However, some of it is over 2" in diameter and thus a crushing and screening process is required to achieve only the desired predominant particle size thai is substantially 2" in diameter or less. No line grinding, pulvcii/mg oi comminution of blast-furnace slag is required by (the present invention The invention provides a method of utilization of \atious blast-furnace .slags in a much coarser .state than previously recognized in lolaly cement kiln processes which allows the elements in the chemical compounds of the blast-furnace slag, i.e., silicates, and aluminosilictes of calcium, and the like, to become an integral part of tiie cement clinker. As- understood by those skilled in the art, the chemistry of the slag must be understood and controlled as pari of the overall ingredients of the cement and thus the quantity of the blast-fuinace slag being added to the feedbook brust be balanced with the feed.slock materials and t-'.eir chemical compounds.
In a laboratory furance burst test of 100' \ Mast-furance slag, the melting, point of the blast-furancd slag has determined and is the key to its use in a cement kiln. As canbe seen ot fable in the inching point was determined to be 255C°F/S% 180oC for blast furance slag which allows the blast-furnace slag to 'be added to the feed and of the kiln in farly large particle sizes, the

I AB FURNACE BURANCE BURM
EFFECTS ON SLAG

(Table Remoaved)
Table 1 o;;istrates the effects on blast-furnace slag when heated to various temperatures. The tests set forth in Table I were run 15 minutes at each tempotatare with slag size approximating 3/8" panicles. As a result of the tests, it has been determined tIi;it (he shig will not thicken slurry in the chain section of tliv roiary kiln, cause mua rings or increase dust loss because of particle s'ze. Further, it will reduce moisture content as much as 2.2% or more depending upon the quartify of blast-liiniacc slag. The blast-furnace slag begins to melt and combine with oilier raw materials somewhere between the calcination zone and the burning zone in the rotary kiln. Because of the low melting point, it is not necessary , pulverize or comminute this material such us in the prior art which requires 30% of the material to pass through a
200-mesh screen for a chemical combination with other ingredients. The formation ol silicates and aluminosilicates of calcium and other bases which are similar to cement clinker compounds, if not the same, have already been accomplished in the blast-furnace slag during the steel-making process. These compounds, with the addition of CaO, can be converted to 2CaO • SiO2(C2S), 3CaO SiO, (C3S), 2CaO Fe2O3(C2F), 3CaO ALO3(C3A), and 4CaO AI2O, Fe2O3(C4AF) with very little additional heal. These are the major chemical compounds of cement clinker.
The apparatus of the present invention is illustrated in FIG. 1. The apparatus 10 includes the rotary kiln 12 supported in a well-known manner by flanges 14 that rotate with the kiln. The kiln has a feed-end 16 and a heat-end or burning zone 18. The heat-end IS is tilted downwardly with respect to the feed-end 16 as is well known in the art. A fuel source 20 creates a flame 22 in the heat-end 18 of the rotary kiln 12 to provide a temperature of approximately 15()0°C (2732°F). Cement raw materials or feedstock such as limestone, clay, sand and the like is carried by a variable speed conveyor belt 24 to the rotary kiln 12. If a wet slurry is used, the variable speed conveyot belt 24 will convey the feedstock to a grinder 26 and from the grinder 26 to the feed-end 16 of the rotary kiln 12. The feedstock moves in a stream 28 through the rotating kiln 12 lowaid the flame 22. The well-known chemical processes lake place within the kiln 12 and the cement clinker 30 exits the heat-end 18 of kiln 12 lor further processing. Pollution control devices 32 and 34, well known in the art, are at the heat-end and feed-end, respectively, of the kiln 12. At the heat-end 18. out of the pollution control device 32, waste gases 38 are expelled to atmosphere an'1 leclaimed waste products 40 are recovered. At the heat-end 16, the pollution control equipment 34 removes tin-vaste gasses:'inch are espell and the waste products at 42.
In the present invention, the blast-furnace slag 44 is carried by a conveying device 46, such as a variable speed con\eyor be it, to the feedstock material 48 that is being fed through a dust hopper 56 (FIG. 2) at the feed-end 16 of the rotary kiln 12. A controller 25 controls the speed of the conveyor belts 24 and 46 so that the proper proportion of blast-furnace slag 44 is provided relative to the feedstock depending upon the chemical compositions thereof. Such control is well known in the art and will not be discussed in detail.
FIG. 2 is a diagrammatic representation of the apparatus for providing a separate feed of the blast-furnace slag and the feedstock into the input-end of the rotary kiln 12. In FIG. 2, it can be seen that the bla.st-furnace slag 50 is dropped into a hopper 52 and carried upwardly by a conveying system 54 where it is deposited at 55 so as to pass through the dust hopper 56 to the input-end 16 of the rotating kiln 12. The feed of the material to the input-end of the kiln can be done in any well-known manner. In like manner, the feedstock materia! 58 is dropped into a hopper 60 where it is carried upwardly by conveyor means 62 and dropped at 64 into the hopper 56 for feeding into the input-end '6 of the rotary kiln 12. Fuller the apparatus of FIG. 1 or FIG. 2 produces tl.e desined results.

Table ii sets forth the result of the chemecal analysis of a sample of blast-furnace slag from a blast furance slag stockpile at random. Of course, the chemical analysis of blast furance slag may the values in Table II depending upon the skg.
Table II
BI AST FURNACE Si \G

(Table Remoaved)
It can be seen that the blast-furnace slag composition is suitable for the manufacture of cement.
Tablc III illustrates the typical mix calculations for a feedstock having 0% blast-furnace slag, 89.679'f limestone, 4.12% shale, 4.M29J' sand, and 0.99% shale.
TABLE-: III TYPE I LA MIX CALCULATION - (K7 SLAG
is
(Table Remoaved)
Table IV illustrates a test nii\ calculation having 5% blast-furnace slag, 8b. 1 11% Limestone, 4.14% shale, 3.70% sand, and 0.97% mill scale.
Table IV fYPE I WITM 5r.i H; AST 1-URNACIi SLAG ADDLO

(Table Remoaved)
Table V illustrates a test mix calculation Max int.' 10% Blast furnace slag 82.66% limestone, 2.94% shale, 3.32%' sand, and 1.08% mill .scale.
TABLE: V TYPE I WITH 10% BI.AST-FURNACE SLACJ ADDED


(Table Remoaved)
Table VI illustrates a test mix calculation having 15% blast-furnace slag. 74.22% limestone, 1.68% shale, 2.93% sand, and 1.10% mill scale.
TABLE: VI TYPE 1 WITH \5r,i Bl AST-FURNAC I SI AC, ADDED

(Table Remoaved)
Table VII illustrates a test mix calculation having 30% blast-furnace slag. 1.81% mill scale. 0.33% sand, and 67.80%' limestone.
TABLE-; VII TYPii I WITH 30% BLAST I URNAC H SLAG ADDED

(Table Remoaved)
Clearly, Tables III, IV, V, VI, and VII confirm that the addition of blastfurnace (air-cooled) slag is suitable as the raw material for the manufacture of cement ciinkcr.
FIG. 3 illustrates the process of the present invention wherein the feedstock material and blast-furnace slag are combined as illustrated in FIG. 1 before entering the kiln at the feed-end thereof. At step 76, the feedstock material is provided and combined at step 78 with the blast-furnace slag that has been crushed and screened to obtain particles of which the predominant particle sizes have a maximum diameter of substantially 2 inches or less at step 80. The combined material is then fed into the feed-end of the rotary kiln at step 82.
In FIG. 4, the process feeds the blast-furnace slag and the feedstock into the feed-end of the rotary kiln separately as illustrated in FIG. 2. In such case, at step 66 the feedstock material is provided and conveyed by a conveying means at step 68 to the inlet or feed-end of the totary kiin. The blast-furnace slag is crushed and screened to obtain the particle sizes having a predominant particle size with a maximum diameter of substantially two inches or less at step 72 and the resultant end product is conveyed at step 74 to the inlet or feed-end of the rotary kiln. At step 70, the feedstock and blast-furnace slag is heated in the rotary kiln until cement clinker is formed.
Thus there has been disclosed a method and apparatus for forming cement clinker with the addition of coarse blast-furnace slag which is led, with the feedstock material into the feed-end of the rotary kiln. Coarse blastfurnace slag is defined herein as blast-furnace slag that has been crushed and screened in particles having a predominant panicle size up to a maximum diameter of substantially 2" in diameter. Many advantages are obtained by the present invention. No fine grinding, pulverizing or comminution of the slag is
required. Large quantities of coarse slag up to the predominant 2" particle size can be incorporated into the cement clinker composition with only minor chemical changes required in the regular material fed to the rotary kiln.
No drying of the slag is required. Inherent moisture normally runs one to six percent. In the wet process rotary kiln system, substantial moisture reduction and savings are realized. In the dry process rotary kiln system, the blast-furnace slag may be dried but it is not nesessary.
With the present invention, coarse blast-furnace slag can be utilized in the production of cement clinker by the way of the rotary kiln as part of the initial feedstock. The blast-furnace slag and wet (or dry) feedstock arc injected into the feed-end of the rotary kiln as separate materials. They also may be injected together at the feed entrance of the kiln with prior blending. No plugging of the kiln has been experienced due to mud ring or clinker buildups. In both the wet and the dry process rotary kilns, the blast-furnace slag has a cleaning effect on material buildup as it moves through the kiln.
Only slight chemical changes are required for the normal feedstock to accommodate the blast-furnace slag. This usually means that the feedstock must be richer in lime content. The chemical compound structure of the coarse blast-furnace slag transforms to the desired cement clinker structure during the heat treatment within the rotary kiln by diffusion. Because grinding, pulverizing or comminution of the blast-furnace slag is not required, substantial energy savings are realized using this invention to produce cement clinker. Production increases are almost proportional to the amount of slag utilized. Further, the environmental condition of the rotary kiln process improves because of the low volatile content of the blast-furnace slag. Further, recycling of the blast-furnace slag improves the environment and provides a useful outlet for blast-furnace slag rather than the blast-furnace slag occupying vast areas of land space for storage. Thus recycling of the blast-furnace slag
improves the environment and reduces the cost of cement production substantially.
While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but. on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.




We Claim:
1. A method of manufacturing cement clinker using an elongated rotary
cement kiln having a feed-end and a heat-end, the heat-end being tilted
downwardly with respect to the feed-end, the method comprising the steps of:
directing heat from a heat source into said heat-end of the kiln;
introducing a stream of feedstock material containing lime into said
feed-end of the kiln such that the stream of feedstock material moves toward said heat at the heat-end of the kiln;
crushing and screening air-cooled blast-furnace slag to obtain particles with a predominant size of up to a maximum diameter of substantially 2"; and
adding an amount of said crushed and screened air-cooled blast-furnace slag to said stream of feedstock material at said feed-end of the kiln, such that as the stream of feedstock material and blastfurnace slag moves toward said heat-end, the blast-furnace slag is melted by said heat and diffused into the feedstock material to form cement clinkers.
2. A method as in claim 1 wherein the blast-furnace slag is added to the feed-end of kiln as a material separate from the feedstock material.
3. A method as in claim 1 wherein the blast-furnace slag and the feedstock material are blended prior to being introduced into the feed-end of the kiln.
4. A method as in claim 1 wherein a wet process rotary kiln is used to receive the stream of feedstock material and blast-furnace slag.
5. A method as in claim 1 wherein a dry process rotary kiln is used to receive the stream of feedstock material and the blast-furnace slag.
6. A method as in claim 1 wherein said blast-furnace slag has a chemical composition of silicates and aluminosilicates of calcium.
7. A method of cement clinker manufacture substantially as herein described with reference to and as illustrated by the accompanying drawings.

Documents:

2180-del-1995-abstract.pdf

2180-del-1995-assignment.pdf

2180-del-1995-claims.pdf

2180-del-1995-correspondence-others.pdf

2180-del-1995-correspondence-po.pdf

2180-del-1995-description (complete).pdf

2180-del-1995-drawings.pdf

2180-del-1995-form-1.pdf

2180-del-1995-form-2.pdf

2180-del-1995-form-3.pdf

2180-del-1995-form-4.pdf

2180-del-1995-form-6.pdf

2180-del-1995-gpa.pdf

2180-del-1995-pa.pdf

2180-del-1995-petition-138.pdf


Patent Number 254004
Indian Patent Application Number 2180/DEL/1995
PG Journal Number 37/2012
Publication Date 14-Sep-2012
Grant Date 12-Sep-2012
Date of Filing 27-Nov-1995
Name of Patentee TEXAS INDUSTRIES INC.
Applicant Address 1341 W. MOCKINGBIRD LANE, DALLAS, TEXAS 75247, USA
Inventors:
# Inventor's Name Inventor's Address
1 ROM DEWITT YOUNG 411 TOWN CREEK DRIVE, DALLAS, TEXAS 75247, USA
PCT International Classification Number C04B 7/147
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 08/404,902 1995-03-15 U.S.A.