The interest of cement manufacturing in Saudi Arabia has started a long time ago where the dawn of this industry was the foundation of Jeddah cement (foundation
1374) although the planning of the cement integration industry commensurate with the kingdom's development plans and the importance of cement choice is because of the property it has such as coherence and cohesion that let the cement formats coherent structural blocks resulting from grinding and smoothing and roosting a mixture of limestone and mudstone with a small ratios iron oxides and SiO
2 and all that shows us what is the cement , what its importance and what it's the importance of its choosing.
(Qadi et al ., 1999).
There are some important sites for cement manufacturing in Saudi Arabia, and those are:

Jeddah cement factory (1374) exports 3000 tons/year.

Yamama company in Riyadh (1966).

Qassim cement company near Buraidh (1400) and it reaches 141000 tons in
1996.

Yanbu, ArAr and Tabuk but we mentioned the most important sites.
II.
used materials in cement and their sites in nature
The main constituents of cement are:
II.1-limestone (definition, its properties in cement ):
It is a sedimentary rock that is consisting mostly of calcium carbonate ( contains 50% percent of calcite or dolomite ), CaCO
3
, used as a building stone and in the manufacture of lime, carbon dioxide, and cement
(periodic media number 5 (1990) The Ministry of Petroleum and Minerals Resources)

Clay (definition, its properties in cement ) for brick making
Forming properties and cause of choice.
Plasticity , dry shrinkage and dry strength are interlinked properties which comprise the forming behavior of brick clay. Plasticity may be quantified using a 'plasticity index' derived from Atterberg liquid and plastic limits. The plasticity index acts as a guide to the workability of the clay when mixed with water; low values are generally considered acceptable for mechanised stiff extrusion processes, whilst higher values indicate suitability for slop-moulding of bricks by hand . The plastic limit gives an indication of likely shrinkage on drying. Dry shrinkage may be measured accurately using kerosene/mercury volume displacement . Although high shrinkage clays invariably show high dry strength, they may also exhibit a tendency to crack and distort.
Mudstone (definition, its properties in cement ) :
A fine-grained, dark gray sedimentary rock, formed from silt and clay and similar to shale but without laminations
Mudstone (also called mud rock) is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm (0.0025 in) with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the appearance of fissility or parallel layering. This finely bedded material that splits readily into thin layers is called shale, as distinct from mudstone. The lack of fissility or layering in mudstone may be due either to original texture or to the disruption of layering by burrowing organisms in the sediment prior to lithification. Mud rocks, such as mudstone and shale comprise some 65% of all sedimentary rocks. Mudstone looks like hardened clay and, depending upon circumstances under which it was formed, it may show cracks or fissures, like a sun-baked clay deposit.
( minerals for development 1835)

Limestone is contained in rocks of diverse origin usually containing calcium carbonate or calcium-magnesium carbonate although they constitute just 0.25% of the earth's total crust, carbonates account for 15% of the sedimentary section. Geographical distribution is virtually ubiquitous, and deposits range in age from
Precambrian to Holocene. Limestone is by far the most widespread carbonate, followed by dolomite and the metamorphic product marble. These three are also the most commercially significant. Related materials include marl, travertine, carbonatite, shells, vein calcite, and aragonite sand.
Limestone is formed in two ways. It can be formed with the help of living organisms and by evaporation.
Ocean-dwelling organisms such as oysters, clams, mussels and coral use calcium carbonate (CaCO3) found in seawater to create their shells and bones. As these organisms die, their shells and bones are broken down by waves and settle on the ocean floor where they are compacted over millions of years, creating limestone from the sediments and the pressure of the ocean water.
The second way limestone is formed is when water containing particles of calcium carbonate evaporate, leaving behind the sediment deposit. The water pressure compacts the sediment, creating limestone
.
Mudstone
Mudstone is formed from fine grained and worn rock material that is then transported to lakes and seas where it settles as clay or mud. This rock is then compressed under the weight of water where the water is squeezed out for particles to cement together.
Limestone (calcium carbonate) is used in cement because it is the key ingredient in its manufacture. Limestone provides quicklime (calcium oxide) when heated. This is blended with other materials like gypsum and ground to make cement.
III. cement industry
There are three ways to find a chemical compound optimization Cement .
III.1Wet method
Is the selection of raw materials and mixes with water to give the result of hanging

up the temperature of the raw materials (1430-1650) ° C , the clinker is formed when the ( 1480 ) ° m of this process depends on :
III.1.1. Crushing and mixing of raw materials
Break the raw materials of limestone and silicate , clay surface and dust , by crushers
, then dissolves and mobility, to be stored in the form of piles in areas open or
Magnetit .
2. Grinding
Movement of materials fifty in the mills pendants, where the mix of water and continue grinding suspense until it reaches the degree of softness required , transmits commentator then to the storage silos , where it becomes homogeneous after setting the final of its components, and take him samples periodically to ensure matching fittings specifications , then transported commentator to pendants basins , where the mills are converting to a homogeneous mixture .
3. The oven and cooled
Pulls commentator of pond bottom to slot fed rotary kiln (oven cylindrical long ), padded inside bricks heat , and slowly rotating slightly tilted from the horizontal plane. This allows the inclination to pay the contents of the oven during rotation forward. Are generated at the front end ( bottom), of furnace high temperature combustion gas flow to the upper part ( rear) of the furnace in the opposite trend to the movement of the contents of the oven surging down, the clinker is cooled by air cooler .
4. The final grinding and packing
Convey clinker to Core mills , where it is added gypsum and milled , and then packaged in bags.
III.2. Dry method
I 've taken using dry processes for the cement industry to spread to gradually replace wet processes , because of the abundance of energy which is characterized by dry processes , and precision in control processes and mixing of raw materials , without the addition of water . Major operations in this way are:
Crushing and mixing of raw materials
Break the raw materials of limestone and silicate , clay and dust surface by crushers,

then dissolves and mobility, to be stored on board piles in open areas or covered .
Grinding
Is the introduction of raw materials in the dryer roundabout , where dried by hot air or exhaust resulting from the operation of the furnace, and then grind the raw materials in the mills of raw materials and transported to silos storing pre- mixing, where they become homogeneous by compressed air , then the movement of raw materials heterogeneous from storage silos before mixing into storage silos . mixing process is 30% clay and 70 % limestone .
The oven and cooled
Withdraw heterogeneous raw materials from the bottom of the storage silos to the heating tower feed slot with the various stages primary , may reach 120 m high tower . Uses natural gas or fuel oil as a source of thermal energy , and uses hot air caused by the cooling clinker as an additional source of heat. Tends oven a little on the horizontal plane so as to allow slow motion of solids to the bottom, cut off the distance to the feed slot at the top of the oven to the lower limb ( hand combustion
), where the combustion gases generated high heat in a time period ranging from (1-
3) an hour, while moving the combustion gases to the top in the current opposite to the movement of solids. hot combustion gases is working on the heating of raw materials , when the oven and feed slot availability of calcium carbonate .
The final grinding and packing
Convey clinker to the Core mills where gypsum is added to packaged in bags .
III.3. Semi-dry method
The semi-dry method is a special case of dry processes , where the oven is used ( for urinating Killen ) or furnace provider pole , in both cases constitute raw materials milled in dry processes , in the form of granules ranging in diameter ( 10-15 mm) , where , in addition to 13 % of water.
The impact of the cement factory on human health.
Diseases caused by the cement - making and dealing with Lament , which lead to serious illnesses like:-
Lung saturation with Lament diseases.
is a fibrosis that affects respiratory bronchi and the lung , the cause of this disease is inhaling cements dust , and the size of the particles do matter because when the size is bigger than 10 micro becomes more likely to cause the fibrosis.

Prevention methods
- working in a humid atmosphere or in a covered devices placed in low places . -
Workers must take anti-dust masks . - You must observe air at least once a month. - accept worker only with a certificate of competency by a doctor , this certificate must be renewed at least once a year. - Workers are not accepted under the age of 18 years, and those who suffer from total disability or from poor health.
Lung Trays.
This disease is caused by inhaling the dust of silicium oxide or slice (sio, and the last one is the only one that causes trays lungs , as the business that gives Dust containing it , a particle diameter less than (5 microseconds) , and the danger starts when the particles are more than a number 3000-4000 molecules in molecule ( cubic cent ) , from the air.
Prevention methods
Prevention of this disease does not have any treatment that can stop the process of pulmonary fibrosis . , the only solution is to keep the worker away from the dust.
Inflammatory disease of the skin
This disease is the most dominated diseases and causes skin infections and those people who exposed to these kind of injuries are the ones who are dealing with cement. Where you note these infections at the level of the neck and shoulders for people who move the cement , especially in the hot weather. Cement intensity base ph> 10) ( this play a role at the level of respiratory tract , causing inflammation of the mucosa of the nose , which can develop into a hole in the nasal barrier . the most susceptible members to inflammation of the skin : ( back, hands, fingers, nails , feet, face), and at the eye level the disease causes a sharp inflammation such as inflammation of the connective tissue of the eyelids , and appear in a type of allergic reactions ( severe sore eye , tears ) .
Prevention methods
- reduce the cement connection by using gloves. - Good physical care with hand washing with pure water .- New workers must undergo medical selection , since the people who have sensitive skin cannot work in these places. - Work in an open air.
Impact on the human hearing
Noise is a health problem for the factory workers and the neighboring population and it can cause for them diseases such as high blood pressure .
Prevention methods
- observe the machine and watch those pieces that make noise and change them -

Must isolate the most noisy machines in private places . - Workers must wear masks and ear Close .
An example of cement-making in Duba (Tabuk region) introduction
In response to a Government proposal for the construction of a cement factory in
Tabuk region (BRGM) was requested by (DMMR) to investigate possible resources of usable raw material in four areas (Ar'ar ,Al Harrah , Al Jawf and Duba ). Duba was selected as the best area to extract the limestone due to the near distance from the factory. intensive surface reconnaissance resulted that the best areas for the raw material are
(Wadi Salma, Shurma and Maharish) the last one (Maharish) contains Limestone and
Gypsum which are compatible with the requirement for cement manufacture.
Manufacturing (specifications)
Cement-making in Taubk cement factory based on special standards .cement manufactures from clay and limestone In precise proportion to adjust the requirement of Fe2O3 ,Al2O3 , CaO and Cio2. The acceptable thresholds of the major impurities are 3% of MgO and 0.025%-.5% Cl, and the levels of alkalis and P2O5 should be very low.
Secondary components
Raw materials which feature pozzolanic properties when mixes with clinker (5-40%)
Portland clinker. This improvement appears to be desirable given the condition of cement use in Saudi Arabia . the nearest known pozzolans are located in volcanic cones of pyroclastic rock at Harrat Lunayyir to the east of UmmLajj. http://minerals.usgs.gov/minerals/pubs/commodity/cement/mcs-2013-cemen.pdf
http://minerals.usgs.gov/minerals/pubs/commodity/cement/myb1-2011-cemen.pdf