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Cement Manufacturing Process Bonardo Pangaribuan



Definisi Semen Semen berasal dari bahasa latin “caementum yang berarti bahan perekat. Dalam pengertian umum, semen diartikan “Sebagai bahan perekat yang mempunyai sifat-sifat yang mampu mengikat bahan-bahan padat menjadi satu kesatuan yang kompak dan kuat”



Definisi Semen Semen Portland adalah : Semen hidrolisis yang dihasilkan dengan cara menggiling terak semen portland terutama yang terdiri atas dan digiling bersama-sama dengan bahan tambahan berupa satu atau lebih bentuk kristal senyawa kalsium sulfat dan boleh ditambah dengan bahan tambahan lain



Mineral pembentukan Semen



Sejarah



Sebelum mencapai bentuk seperti sekarang, perekat dan penguat bangunan ini awalnya merupakan hasil percampuran batu kapur dan abu vulkanis



Sejarah Baru pada abad ke-18 (ada juga sumber yang menyebut sekitar tahun 1700-an M), insinyur asal Inggris - menemukan kembali ramuan kuno berkhasiat luar biasa ini. Dia membuat adonan dengan memanfaatkan campuran batu kapur dan tanah liat saat membangun menara suar Eddystone di lepas pantai Comwall, Inggris.



Sejarah Ironisnya, bukan Smeaton yang akhirnya mematenkan proses pembuatan cikal bakal semen ini. Adalah , juga insinyur berkebangsaan Inggris, pada 1824 mengurus hak paten ramuan yang kemudian dia sebut semen portland. Dinamai begitu karena warna hasil akhir olahannya mirip tanah liat , Inggris. Hasil rekayasa Aspdin inilah yang sekarang banyak dipajang di toko-toko bangunan.



Content Overview



Raw Material Extraction & Preparation Raw Meal Preparation



Clinker Manufacture Cement Grinding Packing & Dispatch



Content Overview



Raw Material Extraction & Preparation Raw Meal Preparation



Clinker Manufacture Cement Grinding Packing & Dispatch



Overview Mechanical Processes Raw Materials Calcareous Argillaceous Silica correctives Iron correctives



Quarrying Crushing Pre-blending Grinding Homogenizing...



Thermal Process



Mechanical Process



Alternative



Raw Meal



Fuels



Gypsum



Clinker Burning... Chemical Processes



Mineral Components



Cement Grinding Blending...



Dispatch



Production Flow of Dry-Process Cement



Stepping Process of Cement



Cement Grinding Clinker Manufacturing Raw Meal Preparation



Raw Material Extraction & Preparation



Content Overview



Raw Material Extraction & Preparation Raw Meal Preparation



Clinker Manufacture Cement Grinding Packing & Dispatch



Raw Material Main Raw Mix Components



Calcareous (Calcium/Lime) Materials -- CaCO3 (Limestone) bring CaO



Argillaceous Materials -- SiO2, Al2O3 & Fe2O3 (Clay, Shale, Marl)



Compositions



Limestone, + 82%



Clay, + 13.5%



Silica, + 3%



Raw Meal



Iron Sand, + 1.5%



Drilling and Blasting



Haulage and Loading



Crushing ...  Purpose: to crush big rocks



into required small rocks  Maximum feed size 



Limestone: 1,500 mm



Shale / silica sand: 500 mm  Product size: max. 75 mm 



Crusher



Pre-homogenezation



Stacker/Reclaimer Configurations SIDE RECLAIMER CONICAL SHELL



CHEVRON CHEVCON



WINDROW



Not applied



FRONT RECLAIMER



Front Acting Reclaimer and Circular Storage Stacker – Circular Storage



Side Acting Reclaimer



Summary 1st Step



Content Overview



Raw Material Extraction & Preparation Raw Meal Preparation



Clinker Manufacture Cement Grinding Packing & Dispatch



Raw Materrial Grinding ....



Tube mill Vertical mill



Bin – bin Raw Material  Purpose: to temporary



storange and weighting raw material  Proportion raw material



LS, Clay, Iron ore, Sand



Vertical Roller Mill  Main purposes  



To grind, and To dry raw materials - Using exhaust gases from the kiln



 Product (“Raw Meal”)  







Fine powder Maximum size 90 micron Moisture of 1%



Vertical Roller Mill



Processes inside ..... • Grinding ▫ The material is trapped between the rollers and the table • Drying ▫ When the hot gas contact the material leaving the table • Transport ▫ From the table to the separator and filter by the gases • Separating ▫ The fine product from the coarses



Process : Grinding View from side



View from top



VRM – Process Inside Gas & Product Material Feed Material



Separator: removes fine material rejects coarse material



Internal gas flow



Separator Rejects Internal Circulation Large Material falls through to scraper



Material



Material & Gas Gas



Product is Raw meal



10 cm



90 m



VRM - Some Common Mill Configurations



G.Pfeiffer



Loesche



FLS Atox



Polysius



Raw Meal Homogenisation ... In Filter



FR



FR



Out Bypass



HS GKA



GKJ



Active Inactive



GAS



The raw meal is homogenised by a combination of the way it is added to/extracted from the silo and the air mixing in the silo.



Summary 2nd Step



Content Overview



Raw Material Extraction & Preparation Raw Meal Preparation



Clinker Manufacture Cement Grinding Packing & Dispatch



Process:Preheating/Pre-calcination...



Process:Preheating/Pre-calcination... Stages 1



315



50



Raw meal Exhaust gas



500 315 2



660



500 3 785 660



4



880 785 5 1000 0



500 Temperature 0C



1000



Process:Preheating/Pre-calcination... The preheating and precalcining processes are done in the preheater tower. In just a few seconds the raw meals is heated from 50oC up to 870oC and calcined up to 95% (CO2 dissociated) Temperature Type of reaction 20 – 100 Evaporation of free water 100 – 300 Loss of physically adsorbed H2O 600 – 900 Dissociation of carbonates (CO2) > 800 Formation of C2S, C3A and C4AF



Kiln



Process:Burning inside the Kiln a rotating steel tube 40 – 230 m long 2.5 – 7.5 m diameter Protected by refractory materials (resistant to heat) • Slope ~2 – 3o • Sinters material to clinker • • • •



Process:Burning inside the Kiln



Temperature



Type of reaction



> 1250



Liquid phase of C3A and C4AF forms



~ 1450



Complete of reactions and crystallizations of C3S and C2S



1300 - 1250



Crystallizations of liquid phase mainly aluminates and ferrite



Fuel  Heavy Fuel Oil  Pulverized Coal ( Sub-Bituminous &



Lignite)  Natural Gas  Pulverized Petroleum Coke



Fuel A complex burner is used to mix different fuels with air and deliver them to the burning zone of the kiln for combustion



Process: Clinker Cooling ...



Process: Clinker Cooling ...  The cooling occurs …



Kiln Clinker



Inside the kiln (cooling zone) - From 1,450 to 1,100oC  In the Cooler - From 1,100 until about 100200oC  Purposes  Heat recuperation  Safety for transport system and storage  Clinker Quality 



Cooler



Product is Clinker



Quality of Meal (Formula) LSF =



(100C) (2.8S + 1.1A + 0.7F) 90 – 105



(S) SM = (A + F) 2.1 – 2.5



(A) AM = (F)



1. 2 – 2.0



Sequences of chemical reactions Proportion



CaO



82.2%



51.6



3.8



1.4



0.4



Sand



2.9%



1.7



85.8



5.2



2.1



Clay



13.5%



2.6



55.7



16.2



6.1



1.4%



5.3



18.6



4.8



60.6



100%



42.9



13.4



3.6



2.1



Limestone



Iron ore



LSF = 100 Primary ingredients in kiln feed (raw meal)



SiO2 supplay Al2O3 These



SM = 2.3



Fe2O3



AM = 1.7



Sequences of chemical reactions CaO CaO CaO CaO CaO SiO2 SiO2 SiO2



CaO



CaO SiO2 1450oC



CaO



Al2O3 Fe2O3



Chemical reactions



Composition of Clinker Clinker Phase



Content



C3S



„Alite‟



~ 60 %



C2S



„Belite‟



~ 20 %



C3A



„Aluminate‟



~ 10 %



C4AF



„Ferrite‟



~ 10 %



In minor amounts :   



Free lime (CaOfree) Periclase (MgO) Alkali sulphates (Na2SO4, K2SO4)



Product is Clinker Minerals



alite



(under Microscope)



Summary 3rd Step



Content Overview



Raw Material Extraction & Preparation Raw Meal Preparation



Clinker Manufacture Cement Grinding Packing & Dispatch



Compositions



Clinker,



Gypsum,



Cement



MIC,



Cement Grinding....



Cement Grinding....



Operation principle of a Tube mill



Cement Grinding...



Cataracting motion for coarse feed Cascading for fine material



Cement Grinding...  Purpose 



To store cement



 How to Discharge 



For bag cement, through - Rotary packer







For bulk cement, through - Loading spout



Product is Cement



Summary 4th Step



Content Overview



Raw Material Extraction & Preparation Raw Meal Preparation



Clinker Manufacture Cement Grinding Packing & Dispatch



Cement Storage, Packaging & Dispatch Layout of dispatch / shipping station Cement from the mills Storage Cement Silo



Cement Silo



Dispatch/Transport Packing & Loading



Cement Packaging



Cement Palletizing



Bag Loading of Trucks



Bulk Loading of Trucks