The manufacture of Portland cement depends upon many factors, including chemical composition of raw materials, firing temperatures, and particle size. Of particular interest in Particle Size Measurement of Cement by Laser Diffraction Using Microtrac S3500 is particle size measurement, since it can affect the efficiency of process grinding and quality of the final product. While there is continuing progress in automated process control, many plants throughout the world control grinding manually and measuring particle size by Blaine air permeability, Wagner photo-sedimentation, and sieve particle size techniques. Blaine and Wagner values are generally related empirically to surface area, which is an indicator of fineness while sieve values provide information on the coarser portion of the particle distribution. These methods do not lend themselves to timely measurements and, therefore, lag various stages of production. The Microtrac particle size analyzer has been used for over 20 years to shorten the time between measurement of particles and process intervention indicated by particle size while aiding the quality control efforts.

Coal represents a major contributor to the production of electric power. It also provides coke for production of steel, gasified coal for production of carbon monoxide and hydrogen to produce Tylenol and NutraSweet, and coal tar for light oils and ammonia. The large amount of coal used for power generation produces by-products that are deemed deleterious: sulfur dioxide contributes to production of acid rain; nitrogen oxides contribute to acid rain, ozone, and smog; particulates contribute to production of smog; CO2 is believed by some scientists to contribute to global warming. The Clean Air Act of 1970 advanced a beginning to reduce the quantities of these substances emitted to the environment. Subsequent acts placed further requirements to reduce environmental exposure to acid rain (1990) or to adopt Clean-Coal Technology (2005).

Use of Electric Power Generation By-Products in Wallboard, Cement and Plastics provides a short outline of some of the advances and positive actions taken by the electric power companies to comply with these acts by using by-products of coal burning for electric power.