Zero-liquid discharge technology utilized for Texas pipe mill
TPCO America, the steel pipe-making plant going up near Gregory, Texas, is set to give its host community additional benefits by building a wastewater treatment facility. The multimillion-dollar project not only will serve the pipe plant but also will provide services to Gregory.
This story began with environmental engineering company McWong Environmental Technology (MET) receiving a request for proposal from TPCO for design-build circulating cooling water systems and wastewater treatment facilities on Oct. 9, 2012. Planning to build a seamless pipe mill that includes steelmaking, continuous casting, hot pipe rolling, heat treatment pipe finishing and complete utilities, TPCO also made a commitment to the state of Texas that its pipe mill will be an environmentally friendly manufacturing facility.
TPCO’s new 253-acre Texas pipe mill is designed to produce approximately 500,000 metric tons per year of seamless steel pipe. In order to properly run this manufacturing facility, the engineering requires building circulating water treatment facilities with daily treatment capacity of approximately 7,000 cu meters for the steelmaking, continuous casting and pipe rolling lines, as well as the heat treatment and finishing lines. Water used for cooling the steel and pipe and for flushing the flume contains scale, oil, grease, chemical oxygen demand, and other chemical contaminants, and must be cleaned before being circulated back to the cooling systems.
Free From Contamination
MET was given the opportunity to offer water recycling, reuse and zero-liquid discharge solutions to the pipe mill. The $80 million project not only will clean up the contaminated cooling water within the battery limits of the pipe mill, but also likely will bring dozens of jobs to Texas, where MET plans to house the crucial engineering, design, procurement, and research and development needed to complete the massive facility.
In order to satisfy the water quality requirements of the pipe mill, MET will design and build four water treatment facilities for its pipe rolling, steelmaking, pipe finishing mill and entire plant wastewater treatment station individually. The heat load of the circulating water will be removed by various types of cooling towers. Suspended solids will be separated using an inclined plate settler, horizontal flow or rotational flow sedimentation tanks. An advanced reverse osmosis (RO) system also will be deployed to concentrate the dissolved solids. Solids separated from circulating water eventually will be dewatered using a sludge thickener and filter press. The brine from the RO system will be used for flushing the scale. The entire wastewater treatment system will be able to clean all of the wastewater and will never discharge any of the dirty water to the environment. A portion of the equipment that will serve this pipe mill will be imported from China.
The construction of the pipe mill is scheduled for completion in 2016, and will be one of the largest single investments by a Chinese company in the U.S. manufacturing industry. Meanwhile, the pipe mill will make a contribution to the global economy without polluting land or water.