Clay- Generally speaking clay is defined as an extremely small piece of soil. Clay almost always consists of particles of alumina and silica joined together by water. There are different forms of Clay that differ because of the other compounds that are mixed in with the alumina and silica. For example, in the case of cement we would want very red clay because the red signifies that it also contains iron oxide. It is hard to say where clay would be easy to find on Arda because it is formed by natural occurrences in soild that don’t relate to a specific location. As long as there is soil on Arda it is high likely that clay would be extremely easy to find.

II. How to make cement

The first step in making cement is to gather limestone, clay and pyrite and place them into a large container that will be made out of steel in order to make sure no other chemical reactions occur before the cement making process begins. Then, using a large tool that will probably be made by the hunting group, we will smash all the different substances until they are in small pieces about three fourths of an inch long. Once this is finished the heart of the cement making process begins when all the ground up substances are placed in a kiln.
A kiln is a large steel cylinder that is usually about 200 feet long. The kiln has a hot end and a cold end. The crushed substances are placed in the cold end, and as the kiln rotates they slowly move toward the hot end. The crushed coal is placed at the hot end because it is used as a fuel source for the fire. The whole cement making process can be summarized in five major steps.
Steps:
1. Before entering the heart of the kiln the mixture of ground substances enter a preheating chamber that is attached to the end of the kiln. The tower, which can be made out of steel, contains a series of cyclone chambers, which the ground up substances move through on its way to the kiln. The hot gases exiting the kiln heat the mixture of substances as they “ swirl” through the cyclone chambers.

2. The substances then enter a furnace at the bottom of the preheating tower which can reach temperatures of 900 degrees Celsius. This evaporates any water that might have been mixed with the substances while removing ninety five percent of the carbon dioxide from the limestone, which will leave only lime ( calcium oxide), a process known as “calcining” the lime stone.

calcium carbonate + Heat --->calcium oxide + carbon dioxide
CaCO₃ + Heat ---> CaO+ CO₂

3. The substances then enter a kiln at the cold end and as the kiln rotates it slowly moves towards the hot end, reaching higher and higher temperatures. When the temperature in the kiln reaches about 1200 degrees Celsius many chemical reactions occur. The calcium oxide reacts with silicates to form tricalcium silicate(3CaOSiO₂), and dicalcium silicate(2CaOSiO₂). The calcium oxide also reacts with aluminates to form tricalcium aluminate (3CaOAl₂O₃), and tetrecalcium aluminoferrite (4CaOAl₂O₃).
4. At the hot end of the kiln powdered coal creates a white flame that can reach up to 1870 degrees Celsius. When the materials reach the heart of this flame they are at the end of the kiln and are now partially molten. When they reach the end of the kiln they are red-hot pellets called clinkers.
5. The clinkers are cooled down and then grinded up until they are in powder form.. Once the cement is in powder all one has to do is add water and then cement is ready to go. The process of when cement is mixed with water is called hydration and consists of many chemical reactions. See Diagram.

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