1. Guided by:- Ass. Prof. Piyush modi Dept. of Chemical Engg. Pacific School of Engg. Surat. Cement

2. Gangani Sandip 131120105012 Dhaduk Nikunj 131120105009 Gojiya Mayur 131120105014 Patel Karan 131120105036 Boghani Divyesh 131120105006 Group members

3. C EMENT Cement is a generic name for powdered materials which initially have plastic flow when mixed with water or other liquid,but form a solid structure in several hours with varying degree of strength and bonding properties which continue to improve with age. The most common is portland cement which is the basis for a number of cement products.

4. P ORTLAND C EMENT It is defined as finely ground calcium aluminates and silicates of varying compositions which hydrate when mixed with water to form a rigid continuous structure with good compressive strength.

5. T YPES OF P ORTLAND C EMENT INormal IIModerate sulfate resistance IIIHigh early strength IVLow heat of hydration VHigh sulfate resistance

6. S TANDARD C EMENTS  Type I: Ordinary Portland Cement Suitable to be used in general concrete construction when special properties are not required.  Type II: Modified Portland Cement Suitable to be used in general concrete construction. Main difference between Type I&II is the moderate sulfate resistance of Type II cement due to relatively low C3A content (≤%8). Since C 3 A is limited rate of reactions is slower and as a result heat of hydration at early ages is less. *It is suitable to be used in small scale mass concrete like retaining walls.

7.  Type III: High Early Strength P.C. Strength development is rapid. 3 days f’ c =7 days f’ c of Type I It is useful for repair works, cold weather & for early demolding. Its early strength is due to higher C 3 S & C 3 A content.  Type IV: Low Heat P.C. Generates less heat during hydration & therefore gain of strengthis slower. In standards a maximum value of C 3 S&C 3 A& a minimum value for C 2 S are placed. It is used in mass-concrete and hot-weather concreting.

8.  Type V: Sulfate Resistant P.C. Used in construction where concrete will be subjected to external sulfate attack – chemical plants, marine & harbor structures. i) During hydration C 3 A reacts with gypsum & water to form ettringite. In hardened cement paste calcium-alumino-hydrate can react with calcium&alumino sulfates, from external sources, to form ettringite which causes expansion & cracking. ii) C-H and sulfates can react & form gypsum which again causes expansion & cracking.

9. R AW M ATERIALS N ECESSARY FOR P ORTLAND C EMENT M ANUFACTURE Calcium Silica Alumina Iron

10. CHEMICAL COMPOSITION OF P.C.  Portland cement is composed of four major oxides (CaO, SiO 2, Al 2 O 3, Fe 2 O 3 ≥90%) & some minor oxides. Minor refers to the quantity not importance.

11. OxideCommon NameAbbreviationApprox. Amount (%) CaOLimeC60-67 SiO 2 SilicaS17-25 Al 2 O 3 AluminaA3-8 Fe 2 O 3 Iron-oxideF0.5-6 MgOMagnesiaM0.1-4 Na 2 OSodaN 0.2-1.3 K2OK2OPotassaK SO 3 Sulfuric Anhydride Ś 1-3 CaO→limestone SiO 2 -Al 2 O 3 →Clay Fe 2 O 3 →Impurity in Clays SO 3 →from gypsum→not from the clinker

12. C63.6 S20.7 A6 F2.4 Ś 2.1 M2.6 N0.1 K0.9 Free C1.4 Total99.8  The amount of oxides in a P.C. Depend on the proportioning of the raw materials and how well the burning is done in the kiln. The chemical composition is found by chemical analysis.  A typical analysis of O.P.C. Insoluble residue=0.2 Loss on ignition=1.4

13. CalciumIronSilicaAluminaSulfate Alkali waste AragoniteCalcite Cement-kiln dust Cement rock ChalkClay Fuller’s earth LimestoneMarbleMarlSeashellsShaleSlag Blast-furnace flue dust Clay Iron ore Mill scale Ore washings Pyrite cinders Shale Calcium silicate Cement rock Clay Fly ash Fuller’s earth LimestoneLoessMarl Ore washings Quartzite Rice-hull ash SandSandstoneShaleSlagTraprock Aluminum-ore refuse Bauxite Cement rock Clay Copper slag Fly ash Fuller’s earth GranodioriteLimestoneLoess Ore washings ShaleSlagStauroliteAnhydrite Calcium sulfate Gypsum

14. COMPOUND COMPOSITION OF P.C.  Oxides interact with eachother in the kiln to form more complex products (compounds). Basically, the major compounds of P.C. can be listed as: NameChemical FormulaAbbreviations Tri Calcium Silicate3CaO.SiO 2 C3SC3S Di Calcium Silicate2CaO.SiO 2 C2SC2S Tri Calcium Aluminate3CaO.Al 2 O 3 C3AC3A Tetra Calcium Alumino Ferrite 4CaO.Al 2 O 3.Fe 2 O 3 C 4 AF

15. M ANUFACTURING OF PORTLAND CEMENT Chemical reaction CaCO 3 1000°C CaO + CO 2 ; +44 Kcal Cao+Al 2 O 3 +sio 2 Mix. Of C 3 s,c 2 s,c 3 A Quntitative requirements (a)Basis: 1 ton of type I cement clay 0.1-0.3 ton limestone 1.2-1.3 tons Gypsum 0.03-0.05 ton Coal 0.25-0.40 ton Water 3 tons Elecctricity 80 KWH (b) Plant Capacities : 200-1200 tons/day

17. PRODUCTION STEPS 1) Raw materials are crushed, screemed & stockpiled. 2) Raw materials are mixed with definite proportions to obtain “raw mix”. They are mixed either dry (dry mixing) or by water (wet mixing). 3) Prepared raw mix is fed into the rotary kiln. 4) As the materials pass through the kiln their temperature is rised upto 1300-1600 °C. The process of heating is named as “burning”. The output is known as “clinker” which is 0.15-5 cm in diameter.

18. 5) Clinker is cooled & stored. 6) Clinker is ground with gypsum (3-6%) to adjust setting time. 7) Packing & marketting.

20. GENERAL INFORMATION ABOUT CEMENT INDUSTRY Cement is a basic material for building and civil engineering construction. Cement is a finely ground, non-metallic, inorganic powder when mixed with water forms a paste that sets and hardens. World cement production has grown steadily since the early 1950s, withincreased production in developing countries, particularly in Asia.

21. MAIN PROCESS ROUTES FOR THE MANUFACTURE OF CEMENT There are four main process routes: 1) Dry process: raw materials are ground and dried to raw meal in the form of a flowable powder. 2) Semi-wet process: the slurry is first dewatered in filter presses.

22. MAIN PROCESS ROUTES FOR THE MANUFACTURE OF CEMENT 3 ) Semi-dry process: dry raw meal is pelletised with water and fed into a grate preheater before the kiln or to a long kiln equipped with crosses. 4) Wet process, the raw materials (often with high moisture content) are ground in water to form a pumpable slurry.

23. BEST AVAILABLE TECHNIQUES FOR THE CEMENT INDUSTRY Heat recovery from waste gas. Power management systems. Grinding equipment and other electricity based equipment with high energy efficiency. Careful selection and control of substances entering the kiln can reduce emissions.