23/8/2014 Ask Dr Clark - Raw materials | Whitehopleman
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Q:What is Integrated Value for SO3 and LSF ?
can u please send me the Values as per details below: Previous Data Current Data Mixed Bed LS Pile (with Clay-1500 Tons) Qty Total -30,000 Tons LS Pile (without Clay) Qty Total- 30,000 Tons Pile set Point for SO3 0.71 Pile set Point for SO3 To be Investi gate? for LSF 112 for LSF -To be Investigate-? Clay Composition SO3 is 3% and LSF is 11 Waiting the response soon.
It is not entirely clear to me what you are trying to do? Please explain. The correction of the lime content for SO3 c ontent is: %CaO - 0.7*%SO3. This derives derives f rom the molecular weights of CaO (=56) and SO3 (=80). 56/80 = 0.7.
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Q:what happen when i increase the vrm inlet air temperature and water pressure also
This depends on the c ontrol loops applied to y our VRM in your control system.
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Q:how much velocity is required for 1 kg of air at 38 degree celsius temprature to transport a coal partical of size 90 micron to a height of 2 meter?
please provide air and coal conveying calculation with formula if possible and please specify any assumption have taken in this calculation....
I only have rules of thumb. If the conveying distance is <30m then you need 0.2 kg of air per kg of coal. If the distance is further then you need more air. Also the dimensions of the piepwork must be suffic ient to ensure a conveying velocity of 25 m/s minimum, and ideally in excess of 30 m/s.
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Q:Do you have such si te for coal prparation
Please explain what you mean?
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Q:Is there any graphical representation or any excel sheet which shows what is the relation between the coalsh and coal tph.
As we know in our cement plant that when ever coal ash increases the % c oal consumption increases. Do we have any excel s heet or any graph which shows what is their relation and how much percentage the coal c onsumption increases by % ash increase.
Such a spreadsheet and chart should be easy to c onstruct. As the ash content of c oal rises so the calorific value will reduce. That means that you need more coal to maintain constant calorific input to the kiln.
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Q:What is the possiable reasons of ring formation inside ball mill?
ring sample analysis sio2 13.75 Al2o3 3.7 Fe2o3 2.35 cl 0.14 cao41.43 mgo 1.9 na2o 1.65 k2o .7 caco3 73.95 mgco3 3.93 water content 5% note clay water content 8 %li me stone water content 3.9%
There should be no ring formation in a ball mill as the action of the grinding media should prevent any material sticki ng to the liners inside the mill. Damp material may stick to the mill li ners when the mill is standing. Perhaps such material could s tick right around the mill liners during slow turning of the mill.
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Q:Burning SR and NP clinker?
Hi Dr. We are making both SR and NP types of cl inker. While making NP our alumina ratio target is 1.6 while making SR our alumina ratio target is more like 0.8. Should these ratios be affected by making different clink er or should we adjust to k eep the ratio constant? One of the reasons I am asking is because i recently began working here and they are currently doing raw mix control based around C3S, C3A and Fe2O3 and I would like to see this s witched to LSF, SR, and AR. The people here have the understanding that if you have C3S, C3A and Fe2O3 on target the LSF, SR, and AR will als o be on target. Should we be able to maintain the LSF, AR, and SR for different clinker types while obtaining a different C3S in the final clink er?
You need to lower the alumina ratio when main s ulphate resisting cli nker in order to reduce the C3A content of the clink er. When the potential C3S, C3A and Fe2O3 contents of cinker are used for raw mix control you have to make an assumption about the degree of
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23/8/2014 Ask Dr Clark - Raw materials | Whitehopleman A: A: A: A: A: A: A: A: A:
combination of the cl inker and the residual free lime in cli nker. When controlling to LSF, SR and AR you do not need to do that.
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Q:What is SO3 in clink er if SO3 in lime stone is 0.35%.
Sulphur in Petcoke is 6-6.5%.Petcoke is firing in kiln with a 40-45% of total coal consumption per hour.if any direct f ormula/calculation is t here for getting SO3 in clinker.Please suggest.
The contribution to the clink er SO3 from the limestone will be given by 0.35 x 0.8 x 1.55. The contribution from the fuel will be given by SO3 content of fuel x kg fuel/k g clinker.
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Q:new cement plant to be built and needs expert advice
do you offer such a service i n which you provide expert advice for newly built c ement manufacturers?
Certainly. That is our main line of busi ness.
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Q:High MgO limestone
We are in the process of doing s ampling of limestone to check on their quality before making a proposal to acquire the li mestone hill f or setting up an integrated cement plant.We have taken random surface samples covering about 10% of total hil l area and found out that CaO/MgO reading as follows 55.3/0.22,
55.2/0.25,53.3/1.49,51.8/2.79,41.3/11.0,36.4/13.9,54.1/1.32,55.4/0.17,48.6/6.16,55.5/0.24.We have now used jack hammer so that we can deeper sample at the high MgO areas again just to retest the quality..Do u expect difference in MgO level between surface sample and sample at 2 feet depth?Is the limestone hill usable if we carefully mix it?What is the li mit for MgO at raw mix stage?Can we use the high MgO limestone as additive for c ement grinding? Appreciate your further advice on our next st ep.
I know no reason to expect a difference in MgO content of the limestone between surface samples and those at 2 feet depth. Based on the information provided some of the limestone is high purity and therefore certainly useable with careful blending. 3% MgO in limestone is the maximum limit, dependent to some extent on MgO content of secondary materials and your national standard for cement. The high MgO limestone can be used as an additive f or cement grinding.
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Q:Which slag is suitable for producing Portland slag cement ?
Which slag is suitable for producing portland composite cement? Air cooled sl ag or Blast furnace slag? Tahmid
Granulated blastfurnace slag that has been quenched in water when drawn off the blastfurnace. Air-cooled slag has little or no hydraulic properties and is not suitable.
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Q:How I can detect slag i n Portland Composite Cement
Dear Sir, How I c an detect Slag or quantity of s lag mixed in portland composite cement by chemical method? Tahmid
That will be difficult because the slag will be composed mainly of li me, silica, alumina and iron oxide therefore undistinguishable from the clink er minerals by chemical methods.
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Q:Raw Mill Residue
Dear Sir, is there any effect of raw mill residue on the bag house bags either we grind finer or coarser.
No, I don't expect the fineness of grinding the raw meal will have any eff ect on the baghouse bags.
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Q:How I c an estimate flyash,slag,limestone content in portland composite cement
How I c an estimate of Fly ash, slag ,limestone in portland composite cement The best way would be by X-ray diff raction.
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Q:Dear Sir, we are using high sulphur coal. Clinker Lt. wt. is 1300 -1350. we want to inc rease C3S more than 45%. Please advice f or required liquid phase in the cl inker. Our kiln feed LSF= 112, SM= 2.24, Al2O3= 2.9, Fe2O3= 2.4. Our clinker SO3= 2.6 to 2.8
To achieve a higher C3S content in cli nker you need to raise the lime saturation of the clinker. Your kiln feed lime saturation is high but so is your clinker SO3. The full analysis of kiln f eed, coal ash and clink er would be required to properly adtvise you this.
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Q:How to f ix the raw mix ratio with f ollowing raw materials
Dear Sir, I have following c omposition of raw materials. LOI SiO2 Al2O3 Fe2O3 CaO MgO Limestone 42.58 3.24 0.79 0.38 50.01 1.24 Clay 5.87 74.98 8.80 6.20 0.98 0.24 Iron Ore 4.65 9.16 2.00 83.04 0.06 0.41 By using of these raw materials I want to fix the raw mix with following modulus but I can't s uccess to get following target modulus in raw mix HM=2.3 SM=2.5 IM=1.5 Here, I am kindly ask ing what are the ratios of raw mix to get the above modulus of the raw mix. If not, what kind of correcting raw mat should I used to obtain above target modulus in raw mix? Your valuable suggestions will be very appreciable for me Regard Dinesh Koirala
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factor. In order to control 3 rations i n the mix you need four raw materials. You only have 3 so can only control 3 ratios.
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Q:Belite
What is t he major difference between alpha-belite and beta-belite ? H igher content of whic h crystal f orm of belite is preferable ? Explain.
These are different crystal forms of the belite. beta-belite has the most hydraulic reacttivity and this therefore preferred. It is what is normally produced in an industrial cement kiln.
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Q:Laterite
Hello Dr., Can you suggest any material that would replace laterite and still produce high strength cement ? If poss ible ,please state the chemical composition of such material.
Laterite is normally added to cement raw mixes to increase the Fe2O3 content of the mix. Therefore any source of i ron oxide can be used instead of l aterite. Alternatively a higher alumina modulus mix can be prepared which will reduce the amount of l aterite used and still produce high strength cement. The Fe2O3 containing clinker mineral (C4AF) does not make a major contribution to cement st rength.
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Q:Coating
Hi Sir, What is coating index ? what is its significance ?
The coating index is an indic ator the likelihood that a raw mix of a particular chemistry will give rise to coating with the cement rotary kil n.
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Q:Clinker Burning
Hi Sir, What is the general expression for calc ulating burning temperature of cli nker ? There is no general expression for c alculating the burning temperature of cli nker.
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Q:Coal Ash
Hello Dr., How do coal as h gets added to the kiln feed ? Please clarify with explanation The fine coal burnt in the kiln contains some ash. That ash is predominatly sili ca and alumina so the ash combines with the lime from the limestone to produce the clinker minerals C3S, C2S, C3A and C4AF.
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Q:Effect of Ash
What is the effect of as h on LSF, SM, AM of clinker ?
Coal ash is mainly c omposed of silic a, alumina and iron oxide so the LSF is reduced. The effect on sil ica and alumina modulus depends on the exact composition of the ash.
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Q:Hydraulic Modulus
Hello Sir, What is the signifi cance of hydraulic modulus in the present days ?
The hydraulic modulus i s the ratio of CaO to the sum of SiO2, Al2O3 and Fe2O3. It was often used historically and for good cement quality, it should be between 1.7 and 2.3. However, this is not a useful as the lime saturation factor so it does not have major significance today.Back to Top
Q:industrial waste in c ement
Sir,Can we use zinc metallurgical waste, jarosite in cement manufacturing process either as raw material for raw meal preparation or as set retarder by partial replacement of gypsum? anybody in the world uses hazardous waste jarosite in cement manufacturing process?
I am not aware of anyone using jarosite in the c ement manufacturing process. The first step would be to know the chemical compositi on of the jarosite.
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Q:Online Analyser for Raw Mix
Hello Sir, Can you provide some i nformation about online analyser used for monitoring raw mix ? Nowadays what are the online analysers cement manufacturer use for controlling the raw mix ? Please advice.
The most widely used would be Gammametrics or the Scantech analysers.
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Q:Lime Saturation Factor (LSF)
Hello Sir, It is found that LSF of output of the Raw mill (Vertical Roll Mil l) is 94% whereas the LSF of Kiln feed is 95%. Can you provide any possible reason for this change ? Please advice.
This might arise from how the dust from the kiln is handled. The kiln feed will contain the dust. The raw mill product might not contain the dust.
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Q:kiln not giving rated production
sir our kiln with c apacity 600 tonns per day is not going on rated capicity.it is operating upto 60% of rated capacity.As soon as f eed rate is increased proper clinker formation does not take place also s ometimes there is sudden feed surge.It also accompanies decaoting and ball formation.What can be the possi ble causes?
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There could be many causes. A technical audt is required to identfy the poss ible causes.
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Q:what happend in k iln when latarite is not gone in rawmeal
The laterite is presumably added for it's iron oxide content. Therefor if has not gone into the raw meal for whatever reason there will be a deficiency of iron oxide in the meal in the kiln. That will mean less liquid phase or fl ux and changed properties of the remaining flux. The clinker will be more difficult to combine therefore fuel consumption is likely to be higher. Coating tendency will c hange and perhaps the coating wi ll be st ripped out of the kiln. Potentially the clink er will be over 100% lime s aturated and there will be high levels of residual free lime.
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Q:Excessiv e Dust in Preheater
Sir our CF is 1.85 you said that it is caused by excessive dust loss f rom the top stage of the preheater. So how do we reduce this dust los s from Pre Heater Section?
That depends on the wider situation. Things to be checked are the condition of the internal fittings (dip tubes, feed distribution plates, feed fl aps) in the preheater. Also the drafting of the preheater, excess air, inleaking air, etc. Als o the fineness of the kiln f eed. The give more specific advice a technical audit would be required.
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Q:Excessiv e fines in raw material
Hi Sir I pos ted a question on excessive fines i n raw material for which you said that the fines c an be added directly to the VRM separator Thanks f or your answer. If we do the above exercise will our clinker factor c ome down? (now it is at 1.85). Is there any other plant where the above exercise is successfully followed. Thanks
There is no reason why the raw mix to cl inker factor would reduce from it's current value. 1.85 is a very high factor which must be caused by excessiv e dust loss from the top stage of the preheater. How you handle the fines in the raw milli ng circuit wi ll not make any
difference in the top stage of t he preheater.
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Q:Excessiv e fines in Raw Material
Hi Sir We are having excessive fines in our raw material. this is directly grinded by Imapct type crusher and is carried to stack er reclaimer. My doubts are 1. Since excess ive fines are there it reduces the capacity of crusher and when it comes to raw mill it is grinded excessiv ely. 2. Our cooler has IKN KIDS and we also are faced with Red river formation and spillage in cooler due to which stoppages happen often. Our suggestion is to provide screen in crusher area to remove excessive f ines thereby improving the capacity of c rusher. I have a doubt on where can the fines be supplied either to raw mill or after raw mill based on the s ize. Please suggest your valuable inputs on how to get rid of this problem.
Certainly a screen to scalp the feed to the crusher seems to be a good i dea. Whether the fines can be added back to the raw mill feed or product will depend on the sieve residues of the fines. One solution would be to add the fines to the separator of the raw mill. Then any material already fine enough will go s traight to the product while the coarser material will be returned to the mill for regrinding.
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Q:method of raw mix pile avg c alculation according to hourly tonnage in excel?
This requires that the weighted average of each oxide in the pile be c alculated after each new sample using the analysis of the sample and the wieght of material added to the pile. The composition to c orrect the pile to target can then be calculated.
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Q:Sir, Why we multiply with 2.8 to Sio2, 1.18 to Al2O3 & 0.65 to Fe2O3 in LSF f ormula i.e. CaO/(2.8SiO2+1.18Al2O3+0.65Fe2O3)
These are the coeffici ents in the Lea and Parker formula for the maximum combinable lime in Portland cement clinker. They are derived from the phase equilibria of t he CaO-SiO2-Al2O3-Fe2O3 system.
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Q:How 5 or more components raw mix design are calculated ?
it is too important for me please answer it to me
By setting up 5 si multaneous equations with the 4 targets in the raw mix that you want to control. Then solvng those s imultaneous equations.
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Q:chemical and physical analysis for white cement (LSF- SIM -ALM & C3S - C2S - C3A - C4AF)?
LSF = 95%, SM = 4+, AM = 10+. C3S = ~60%, C2S = ~20%, C3A = ~15%, C4AF <1%. Strengths higher than grey cement due to higher silicate c ontent.
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Q:lime stone is pure cristaline calc ite @ 87% T.CO3 and in the same bench it has very low T.CO3% as pegmatite or gniees with 16 % MgO , si r our raw mill is 170 TPH VRM and is there any difficulty of raw mill fine grinding of this calcite and gniees
dear sir , good evening. here in kenya we are going to instal 3000 TPD clinker unit with 170 TPH VRM for raw mix and is there any difficult to get fine grinding like 212 mic residue up to 2% and 90 mic residue up to 18% with this lime st one pure calcite c rystalline and bottom layer is very low phlegmatic or genies with 2 to 16% mgo. one place we find low cao stone with 56 silic a and
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i came to know that this stone silic a should not be good reactive as i t formed from calcite washed with water and cao is eliminated. i think that in ball mill we can maintain finesse as we required. please give me reply at the earliest thanking you RAO . Y . S NATIONAL CEMENT CO. LTD NAIROBI - KENYA
There is no reason to suppose that a V RM would not be able to grind this material while a ball mill would.
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Q:Difference Between Limestone & Shale
How to Dis tinguish between Limestone & Shale with chemical compostion.
Limestone is a f orm of calci um carbonate. Pure limestone has 56% CaO. Shale is geologically altered clay so c omposed of alumino silic ate minerals. The CaO content of shale is very low. It's silica content is likely to be around 50-60%.
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Q:Why we set carbonates 77 or 76 per in pile formation ?
what happened when we increase the carbonates or decrease in pile like 70 or 80? why we set 80 or 70 per carbonates in pile formation?
Because that level of carbonate will give you the required amount of CaO in the pile. I f you set lower then you will need to add high grade limestone at the raw mill to bring the kiln feed LSF up to target. If you s et higher then you will have to add si lica, alumina or iron oxide at the raw mill to bring the LSF down to t arget.
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Q:crusher for kaolin
Hi si r What is the best crusher for Breaking kaolin? Also i n our factory for kaolin Breaking use of jaw crusher & Gyratory crusher.What do you think about using impact crusher? Best regards
Impact crushers are normally us ed for brittle materials. Kaolin is normally quite s oft. The only problems that might arise are if the kaloin i s wet and stick y.
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Q:low liter weight cl inker and decrease product
LSF X- RAY : 90-92 SI M : 2.3-2.4 ALM :1.3-1.4 LSF CHEMICAL :88-90 SIM :2.4 ALM 1.3 Well, it seems t hat you X-ray is reading high on CaO, if the c hemical analyses are correct. That does not explain the decreased productivity. My suspicion that there is some other problem.
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Q:How to c alcualate or simulate the alkali enrichment in the preheater when alkali rich material is used as additive?
I am substituting Trass for Sand to get sili ca in the raw mix. The trass c ontains 1.2% K2O and 3.2% Na2O. Consequently, the total alk alies in the raw meal inceases from 0.34 % to 0.56%. How calculate or s imulate the alkali enrichment in the preheater circulation material?
It is of course possible to do this with an Excel based model of the alkali cycles, as I demonstrated at Cemtech in Dubai and Jakarta. However, it is not just a question of calculating. That depends on y he volatility of the Na2O and K2O, which is dependent on the amount of chloride and sulphate present. It is too complic ated for a simple calculation and depends on a model. However at 0.56% total alkali there should be no problems.
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Q:what is sil ica modules & alumina modules give me defination.
Silica modulus is the ration of the %silic a to the sum of the %alumin and %iron oxide. Alumina modulus is the ration of the %alumina to %iron oxide.
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Q:LSF FORMULA
Dear sir,kiln feed is: Cao=42.3%, Mgo=2.7% ,sio2=12.90%, Al2o3=3.37%, Fe203=2.23% .some plants do not consider Mgo in calculation of LSF and they use the formula
LSF=100*cao/(2.8*sio2+1.18*Al203+0.65*Fe2o3)is it right?or they should add 0.75*Mgo in numerator. if we want to announce kiln feed LSF with above analysis what should we say about LSF? LSF=102(without Mgo)or LSF=105(with considering Mgo).
Normally for kiln f eed LSF the MgO is not inc luded.
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Q:Finess of raw meal influenced snow man
Hi Dr Clarck , Can raw meal fineness(212) influenced formation of snowman?
Only indirectly. This will not be the primary cause of snowman formation in a cement kiln clinker cooler.
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Q:what is the ess ential raw materials to produce white cement
Raw materials which give the required CaO, SiO2 and Al2O3 c ontent with the minimum of Fe2O3 contamination. No other first row transition elements can be tolerated, but they are rare components on cement raw materials or fuels.
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Q:Raw mix design of 4 components
How 4 components raw mix design are calc ulated and what are the LSF,SM, and AM for the mix design?
23/8/2014 Ask Dr Clark - Raw materials | Whitehopleman
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and solving 4 s imultaneous equations. The LSF, SM and AM targets are variables within those simultaneous equations. I s uggest that the enrol of the CemNet Cement Manufacturing Technology course.
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Q:Sweetner grade (High Grade ) Lime stone
Sir, Pls tell me, is i t possible that CaO % 57 in Hi gh grade lime stone (Its LSF aprox 1050) The maximum CaO content in pure limestone (calc ium carbonate) is 56%.
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Q:The ingredients in ASTM C150....
Dear Dr. Clark, I have some questions on ASTM C150/C150m-11 Standard Specification f or Portland Cement revised in April 1, 2011. There are several ingredients specif ied in Item 5. Ingredient of the specific ation, 5.1.1 Portland Cement Clinker 5.1.2 Water or Calcium Sulfate 5.1.3 Limestone (not more than 5 %) 5.1.4 Inorganic Processing additions (not more than 5 % ) 5.1.5 Organic Process ing additions (not more than 1 %) 5.1.6 Air-entraining addition Would you be more specific about the following aspects? 1. What's the meaning of Water of "5.1.1 Water or Calcium Sulfate" ? 2. What's the meaning of Processing additions ? What's the difference between 5.1.3 and 5.1.4 ? 3. What's the maximum addition rate ? Not more than 10 %? 4. What's the meaning of 5.1.5 ? Does it mean grinding aids? 5. What's the purpose the us government revised the specification l ike this? For the reduction of CO2 emission? I really thank you for your help up to now! Best Regards.
Dear Obong, The short answer is I don't knnow exactly. I presume the reference to water or calcium sulphate is s aying that the calcium sulphate addition might be gypsum with 2 molecules of water of crystall isation. I think inorganic processing additions are pfa, gbs, etc. so the same as limestone. As f ar as I I am aware the total additions are 10%, including the gypsum. I think organic process ing additions are grinding aids and organic quality improvers. I don't know the motives of ASTM or the US Government but this seems to be a move towards EN197 CEM I cements.
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Q:Intensity of kiln feed
Hi s ir How we c an get the analyze of material , f rom intensity of kiln f eed? Best regard I presume you mean the intensify of the fluorescent X-radiation from a kil n feed sample in X-ray f luorescense spectrometer. These are calibrated so that the SiO2, Al2O3, Fe3O3, CaO, etc.content of the kiln feed is c orrelated with the X-ray intensity.
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