Commissioning a 2.2 mt/y cement plant in Midlothian, Texas

TXI operates and maintains a cement plant in Midlothian, Texas. The original plant consisted of four wet process lines with a yearly clinker production of about 1088400 mtpy (1200000 stpy). The fuels utilized are natural gas and coal along with waste fuels. With the increasing demand for cement in the Texas market, TXI decided to expand the plant capacity by adding a large dry process clinker production line and shut down two of the existing wet kiln lines. Due to strict environmental restrictions, the plant's overall clinker production after the capacity increase had to be achieved while maintaining the new stringent emission permit limits. This was a challenge as the raw materials contain significant amounts of carbon and pyritic sulfur. TXI commissioned equipment for a new 2200000 stpy (6000 stpd) dry clinker production line, designed and supplied by FL Smidth Inc., that more than doubled the yearly capacity of the existing facility. This modem clinker production line incorporates all of the latest technology, in terms of chemical control, emissions control and abatement, and process features that allows the plant to operate under these strict environmental conditions. This paper covers TXI's expansion project and identifies the relevant system design issues and operational results.