Laserfiche WebLink
<br />Southdown News <br />Lyons Cement Plant <br />5134 Ute Highway; PO Box 529 <br />Lyons, CO 80540 <br />(303)823-2109 <br />What is new at Southdown? <br />We are improving cost and quality; while, we reduce waste and particulate <br />emissions. This past spring, the plant submitted an application to amend our air <br />permits to support this work. The project consists of two major operational <br />changes at the plant which will dramatically improve particulate emissions from <br />the facility. <br />1. High Efficiency Finish Mill Separator -- The plant is currently using two <br />obsolete separators in the finish mill circuit. The typical cement particle passes <br />through the mill 4 or 5 times before it is ground to the required fineness. The <br />separator is supposed to separate fine material which requires no additional <br />grinding from the coarser particles. Unfortunately, the old separators do a poor <br />job of this separation. As a result, a substantial amount of fine material is <br />returned to the mill and is ground to "super-fines" . This material is a bad actor in <br />concrete batches because it requires more water to be added to achieve good <br />workability. The higher the water addition, the lower the potential strength of the <br />concrete. <br />The high efficiency will virtually eliminate these super-fines which will result in a <br />dramatic improvement in product quality. As a consequence of this change, the <br />mill capacity will increase slightly which will help the plant meet the summer peak <br />demands for cement. Typically, 70+% of our product is shipped in the six <br />months from May -October, the peak construction season. <br />Air movement is the principle used for separating fine and coarse particles. This <br />high efficiency separator has a iargt:: fan ar~d baghouse as key elements of its <br />operation. Any new discharge to the atmosphere must be permitted. This fan <br />and associated baghouse is a large portion of the permit changes. <br />2. Recycling of CKD - We heat pulverized limestone and shale to 2700 <br />degrees F in our kiln using coal or natural gas. Our Kiln system is equipped with <br />large fans and baghouses to trap the particulate that is pulled through the <br />system along with the combustion gases. The material collected in the <br />baghouse is called "Cement Kiln Dust" (CKD). This material is very close to <br />finished product in its chemical and physical characteristics. Unfortunately, it has <br />a higher sulfur content than desirable. Much of this material is returned to the <br />kiln. However, some portion cannot because of the sulfur limit for our finished <br />1 <br />