In considering concrete foundations
In considering concrete foundations we must recognize that the human factor plays a greater part than where steel or timber is used, for these products come to us with known qualities while concrete has but one ingredient (cement) of the three that is known and we must depend upon a proper selection of sand and [...]
Cement Manufacturing
Industry Description and Practices The preparation of cement includes mining; crushing and grinding of raw materials (principally limestone and clay); calcining the materials in a rotary kiln; cooling the resulting clinker; mixing the clinker with gypsum; and milling, storing and bagging the finished cement. The process results in a variety of wastes, including dust, which [...]
Variability of Portland cement
Portland cement variability can occasionally cause problems. “Are all nominally similar cements the same?” “Does cement from the same source (same cement works, same kiln) always behave consistently?” The answer to both questions is ‘not necessarily.’ That said, let us first look at the other side of the coin. Consider a modern cement works – [...]
Cement hydration
By the process of hydration (reaction with water) Portland cement mixed with sand gravel and water produces the synthetic rock we call concrete. Concrete is as essential a part of the modern world as are electricity or computers. Other pages on this web site describe how PC is made and what is in it. Here, [...]
Cement Manufacturing – the cement kiln
Most Portland cement is made in a rotary kiln. Basically, this is a long cylinder rotating about its axis once every minute or two. The axis is inclined at a slight angle, the end with the burner being lower. The rotation causes the raw meal to gradually pass along from where it enters at the [...]
Cement manufacturing:components of a cement plant
This page and the linked pages below summarize the cement manufacturing process from the perspective of the individual components of a cement plant – the kiln, the cement mill etc.. Summary of production process Cement is typically made from limestone and clay or shale. These raw materials are extracted from the quarry crushed to a [...]
Cement Milling
Cement milling is usually carried out using ball mills with two or more separate chambers containing different sizes of grinding media (steel balls). Grinding clinker requires a lot of energy. How easy a particular clinker is to grind (“grindability”) is difficult to predict, but rapid cooling of the clinker is thought to improve grindability due [...]
Clinker: Cement chemistry notation
Cement chemists use a form of notation which, at first sight – and maybe second or third sight – may seem a little odd. Oxides are referred to by their first letter: ‘C’ represents CaO; ‘M’ is MgO and so on, for all the oxides likely to be encountered in cementitious systems, as shown below. [...]
Cement manufacturing – raw materials
If you happen to be a geologist, the raw materials quarry is probably the most interesting part of a cement works, maybe unless you view the clinkering process as igneous rocks in the making. The most common raw rock types used in cement production are:- Limestone (supplies the bulk of the lime) – Clay, marl [...]
Portland cement clinker
Portland cement clinker is a dark grey nodular material made by heating ground limestone and clay at a temperature of about 1400 C-1500 C. The nodules are ground up to a fine powder to produce cement, with a small amount of gypsum added to control the setting properties. Polished section of nodule (scanning electron microscope [...]