7/30/2019 What is the Cement Manufacturing Process

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What Is the Cement Manufacturing Process?The cement manufacturing process involves several key steps, including preparing the raw

materials, grinding the materials together, heating the newly formed clinker in akiln, and

finishing the cement with fine grinding. Some of the main ingredients used to make cementincludelimestone, clay, shale, iron, and sand. Different manufacturing techniques will use either

wet ordry grinding, but each cement manufacturing process will culminate in heating and fine

grinding to finish the product.

Preparing the raw materials is often the first step in the cement manufacturing process, and

involves mining the limestone or obtaining safe industrial waste products. Drilling, blasting, andcrushing machinery convert mined limestone to fragments about 0.39 inches (about 1 cm) in

diameter, after which it is stored until needed. Crushing practices will sometimes be used on the

other materials as well, especially if they contain large or irregularly sized fragments.

Grinding is the next step in the cement manufacturing process, and it can occur in either wet ordry forms. Wet grinding involves combining all of the materials in a mill with water and

grinding it into slurry. In contrast, dry grinding processes combine and grind the materialswithout water, creating a substance known as kiln feed. Both types of grinding will yield

material that contains an average particle size of about 75 micrometers. After each process, the

materials are further mixed for proper homogeneity and placed in storing units.

Heating occurs next, and it takes place in arotary kilnthat is fired at high temperatures. The kiln

heats the clinker, the name for the dried material formed after the grinding process, until itreaches upwards of 2732F (about 1500C). Afterward, the material is sent to a clinker cooler

where the temperature lowers to a reasonable level, at which point the material can be stored

once again.

The cement manufacturing process is completed when the cooled clinker is ground once again in

a rotating finishing mill. A combination of gypsum and limestone will usually be added in smallamounts to the heated cement during this last grinding step, and coloring agents can also be

added here. The fineness of the finished particles will vary according to individual preferences,

and the cement can reach a level of fineness where it will travel through liquid sieves.

Completion of the finishing step means that the cement is ready to be packaged and distributed tobuilders and consumers.

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