PGNAA Cement Analyzer Optimization

Abstract

Optimizing PGNAA performance in the cement manufacturing process can be achieved with cooperation between the analyzer vendor and plant operations by understanding the limitations of the technology in the process. This paper focuses on optimizing the plant process, belt loading, weigh scale signals and other factors that effect the analyzer results.The first bulk material analyzer utilizing Prompt Gamma Neutron Activation Analysis (PGNAA) technology to measure the elemental composition of raw materials in the cement manufacturing process was installed at an Arizona Cement Plant in 1987. Today, PGNAA analyzers are a staple in most modern cement plants and are used to reduce variations in material composition for improving production quality in the manufacture of cement. Typically, an analyzer is used to build pre-blend limestone stockpiles or to control the composition of the raw mix that is fed to the raw mill. Analyzer measurements allow closed loop automation control of the additive feeders. Some cement plants also use a PGNAA coal analyzer to ensure the consistent fuel quality for the kiln.There are still many new and existing cement plants that are installing PGNAA analyzers in their processes. It is important to understand that PGNAA can provide significant benefits to the production process. To be most successful, the installation and commissioning of the technology requires cooperation between the analyzer vendor and plant operations. Technology advancements have made PGNAA more forgiving to highly variable processes and there are techniques to mitigate sources of performance degradation. However, the technology is bound by laws of physics, and the best analyzer performance can be achieved by following PGNAA optimization guidelines.