Using On-line Nuclear Elemental Analyzers to Optimize Boiler Operation at Choctaw Generation Station in Northeast Mississippi
In fiscal 2001 the Choctaw Generation Limited Partnership put into operation a 440-megawatt power production facility in Northeast Mississippi. The operation is a state-of-the-art facility using clean coal technology to burn lignite coal mined near the plant by North American Coal. The power plant uses twin fluidized bed boilers to generate the steam used to create the power ultimately delivered to TVA. In keeping with the advanced technology used in the original design of the facility, an on-line nuclear elemental analyzer** has been added upstream of the boilers to ensure optimum operation. This paper will take a detailed look at the application and provide data on the benefits of the technology to minimize boiler shutdown and optimize boiler performance.
Using a Nuclear Elemental Static Analyzer to Optimize the Operation of a Preparation Plant
A large coal preparation plant in West Virginia is using a SABIA Model L-2000 to analyze the ash levels in product as it leaves the plant in order to adjust the circuits in real time and optimize the plant output. Operating at nearly 4M tons of coal per year the site delivers both steam and metallurgical coal to customers in the United States and around the world. The static sample analyzer, which delivers a sulfur and ash analysis in 15 minutes or less on one-gallon samples is being used to give the customer a quicker turn around on prep plant adjustments as the coal ash levels vary coming out of the prep plant. This paper takes a look at both the economics as well as application details and the difference this analyzer could make for the operation.
A Report on an Investigation into SABIA’s Ability to Provide a Coal Heating Value Analysis Utilizing Carbon
Beginning in 2000 SABIA began shipping PGNA based analyzers to the customers who processed coal. From the outset, SABIA’s approach for delivering a heating value reading to the customer was a moisture, ash dilution approach based on the following equation:
CV=MAFCV* (100% – Ash% – Moisture%)
Improving Product Uniformity & Process Efficiency in Rapidly Changing Market Conditions Using PGNAA Technology
When the Colorado cement plant was commissioned, its associated quarry and reserves made it suitable and economical to produce an ASTM Type I cement, requiring a low percentage of limestone and a high percentage of shale. As has been the case with many cement plants around the world, changing market conditions and customer demands for ever increasing cement performance forced the plant to move to Type II and Type V production and eventually oil well cements which require a much higher percentage of limestone in the mix. These demands combined with a complex quarry led the plant’s management to utilize an online nuclear (PGNA) analyzer.
Fine-tuning the Raw Mix
Changing market conditions and customer needs can impact significantly on raw material requirements. This shift in raw material specification combined with the complexities of quarrying the right materials has prompted the Cemex-owned Lyons cement plant in Colorado, USA to upgrade its raw material analyisng capabilities.
Using On-line Nuclear Elemental Analyzers (PGNA) to Control Cement Production
Unequaled Homogeneity Now Possible
A Brief History of Cement Production
Even in ancient times the use of cement played a vital role in the advance of civilization. Egyptians used calcined gypsum as a cement and the Greeks and Romans used lime made by heading limestone and added sand to make mortar, with coarser stones for concrete. At some point the Romans discovered that by adding crushed volcanic ash to lime that a cement could be made which set under water and this was used for the construction of harbors. This was later called a ‘pozzolanic’ cement, named after the village of Pozzuoli near Versuvius.
The History and Future of Nuclear Elemental Analyzers for Product Optimization in the Cement Industry
This paper takes a critical look at the use of nuclear elemental analyzers** for the manufacturing of cement- past, present and future. The paper begins with a brief historical tour of analyzers and then discusses in detail the strengths and trade-offs of current equipment, where they work, the value they deliver, and where they failed, concluding with a look at the latest development in the technology, and the future for nuclear elemental analysis in cement manufacturing control and cost reduction.
Lafarge Whitehall Achieves Record Low Kiln Feed Variability with Online Raw Mix Control
Lafarge North America’s Whitehall Plant, located in the Lehigh Valley in Pennsylvania, has one of the company’s most heterogeneous quarries, but due to high silica and alumina content, the raw mix also includes purchased limestone. Reducing quarry variability and improving raw-mix control tend to reduce the used of purchased material, and important cost factor for the plant.
To improve the raw mix control Lafarge Whitehall decided to implement an online raw-mix control strategy using a SABIA on-belt elemental analyzer in conjunction with the company’s proprietary raw-mix software.
Extending the Life of Your Legacy PGNA Cement Analyzer through a 3rd Party Retrofit
PGNA Nuclear Elemental Analyzers are now widely used around the world in the cement industry. They add significant value in controlling the quality of the raw materials prior to firing in the kiln. The two main applications are pile building after the quarry and raw mix control using crushed quarry rock and material additives such as iron, silica, calcium, and aluminum. In almost all cases the ultimate goal is reduced C3S or LSF variability and in many cases the variability is reduced by greater than 50%. It has been documented that this can result in a plant savings of as much as $1M per year for a 1M TPY plant.
The useful life of a typical PGNA Analyzer is somewhere from 10 to 15 years. At that point most customers can either buy a new analyzer or get an upgrade from the OEM, which historically has been a fairly expensive option. Third party upgrades of existing legacy machines are now available, making it possible to have up-to-date technology at competitive prices. This paper will examine the uses of analyzers, the economics for cement plants, and take a quick look at the third party upgrade option now available to the cement market.
Lafarge, Whitehall Opts for PGNA Analyzer
Located in the Lehigh Valley near Bethlehem, Pennsylvania, just a mile away from Coplay, the US birthplace of cement production during the late 19th Century, the Whitehall Plant fired up its first cement kiln in 1899. Originally built by the Whitehall Portland Cement Company, the plant is owned today by Lafarge North America. The plant produced ten different types of cement, addressing a wide market with 700,000 tpa cement production, utilizing two preheater kilns and two raw mills. The relatively urban plant setting requires careful plant operation (minimal dust and noise) and limits the plant’s footprint.
Whitehall’s quarry contains relatively low and variable calcium concentrations in one of the company’s most heterogeneous quarries. Due to the high silica and alumina content, the raw mix also includes purchased limestone. Reducing quarry variability and improving raw-mix control tend to reduce the use of purchased material, and important cost factor for the plant.