World Cement InFocus: Hot Topic Articles: Analytical Solutions

Title: ED (P)XRF: A decade of success
Author(s): Katarína Martauzová, Povazská Cementáren, a.s., Slovak Republic, presents the results of 10 years of experience testing ED(P)XRF technology to establish whether the technique is a viable alternative for analysis within the cement industry.
Synopsis:
- Nearly a decade ago, when EDXRF technology was first proposed for cement industry applications, significant questions were raised regarding the potential risks involved in using such an unconventional measurement technique for this vitally important quality control function. In order to prove the acceptability of the technology, and to disprove any potential risks, Povazská Cementáren, a.s., Slovak Republic, undertook a long-term study. The analyser selected to conduct the tests was the Spectro X-Lab. Even though individual tests had been conducted prior to this undertaking, there was no long-term experience documenting the uninterrupted performance of the X-Lab over time on a cement application.

Title: XRF and XRD based solutions
Author(s): Theodor Feldmann and Rainer Schmidt, Bruker AXS GmbH, Germany, discuss the implementation of industrial strength process and quality analysis tools across the entire cement production process.
Synopsis:
- The control of chemical and mineralogical compositions of both intermediate and finished products, as well as of raw materials, is of paramount importance to the cement industry. This is even truer today as fierce competition grows and cement prices drop, meaning that high quality analyses are required during the entire production process. Currently, determination of chemical composition and free lime are well-established methods, while full phase quantification is becoming a more popular tool for process optimisation. Modern technology no longer requires highly trained specialists to operate X-ray fluorescence (XRF [a method to determine elemental composition]) and X-ray diffraction (XRD [a method to determine phase composition]) systems. This allows ever easier implementation of these reliable and advanced methods in the entire production process.

Title: Multivariable process control
Author(s): Michael Tay and Steve McGarel, Pavilion Technologies, Inc., USA, describe how multivariable process control (MPC) software solutions have reduced energy costs whilst improving product quality and production output at two cement plants.
Synopsis:
- The cement industry is one of the most energy intensive manufacturing industries worldwide. As a result, any reduction in energy use per ton directly reduces production costs and positively impacts upon the profitability of a plant. Process control software solutions have been used in a variety of industries to increase production, improve product quality, and minimise raw material use. In addition, process control solutions have been deployed to reduce energy costs per ton. This paper describes how multivariable process control (MPC) software solutions have reduced energy costs at two cement plants, while simultaneously improving product quality and production output.

Title: On-line raw meal analysis and control
Author(s): Reiner Koenig, APC GmbH, Germany and Adhi Narayanan, CemPro Analytics Ltd, Canada, present results of tests conducted on raw meal samples using a new EDXRF based on-line analyser.
Synopsis:
- Minimising the variation of the raw meal composition and keeping it on target is a major objective in all cement plants. This has substantial direct and indirect cost implications. The traditional method is to take composite samples from the process and analyse them in the laboratory. X-ray fluorescence has been in use for many years for this purpose. The methods and techniques developed over the past two decades provide very reliable and accurate analysis in the laboratory.
  Increasing the frequency of analysis or performing analysis ‘on-line’ is a natural extension of this methodology, in order to provide more information about the process and enable the fastest possible response to process variations. There have been many developments in automating the laboratory, which can generally reduce labour costs and improve analytical quality.

Title: Cement laboratories: State of the art
Author(s): Materials Technology Group, Construction Technology Laboratories, Inc., USA, looks at a number of the newest tools being used in today’s most advanced cement laboratories and how the industry can benefit from their use.
Synopsis:
- Over the past 75 years, scientists and manufacturers have learned much about cement and concrete through laboratory exploration and analysis. And although people might not expect a typical cement laboratory to be high-tech, advances in computer-controlled equipment, robotics, sophisticated software, electronics, and optics are all changing the way work is carried out in cement laboratories. These advances reduce analysis time, increase the accuracy and precision of results, and enhance our knowledge of cement properties. This article discusses some of the newest tools being used in today’s most advanced cement laboratories and how the industry can benefit from their use.

Title: The value of analysis
Author(s): Dr Peter van Velzen, Managing Director, PANalytical B.V., The Netherlands, provides a personal view of the value of X-ray analysis when developing new generations of building materials and manufacturing processes, and managing the environmental aspects of the industry.
Synopsis:
- To be successful, businesses must deliver products and services that add value in ways that distinguish them from their competition. Achieving this demands that suppliers perfectly understand the requirements of, and work seamlessly with, their customers throughout the value chain. In this way they become part of the process of generating and supporting sustainable, competitive and economic advantage. An efficient supply chain is especially important in sectors such as the cement industry where growth over the past decade has been modest and the challenges many. Materials characterisation is an important link in this chain, with X-ray analysis generating invaluable data on various cement processes. This brings the expertise and process monitoring capability needed to develop new generations of building materials and manufacturing processes, and to help manage the increasingly important environmental aspects of the industry.

Title: Raw Mix Control
Author(s): Duane Crutchfield, Lloyd Young, Ash Grove Cement, USA, and Victor Lanz, Analyser Systems (ASYS), USA, discuss the PGNAA driven Raw Mix Control at Ash Grove Cement.
Synopsis:
- Ash Grove Cement Company, the largest independent US cement producer, has standardised on a combination of PGNA online analysers with QCX blend control in six of its nine cement plants. In the summer of 2003 the Leamington, Utah plant installed an ASYS Full Stream Analyser FSA. The following report shows the operating results after 14 months of experience with the new system.
  The Leamington plant produces two types of clinker from the following five raw materials: low alkali shale, high alkali shale, sandstone, mill scale, limestone. Sandstone is imported from a nearby quarry and comes in varying qualities. Limestone is prehomogenised in a longitudinal preblend bed located between the quarry and the plant. One limestone pile is built whilst the other is reclaimed. Changes in chemistry between the two stockpiles are observed. All raw materials are stored in bins for raw mix proportioning and extracted by automatic weigh feeders.

Title: Flexibility in Online Analysis
Author(s): Darrell Leetham and Rick Ackermann, Thermo Electron, USA, look back on a long term involvement with online analysis and the company’s continued contributions to advances in this field.
Synopsis:
- In 1984 a revolutionary new way of process control was introduced to the cement industry from a little known yet innovative company based in San Diego California. That same company, originally known as Gamma-Metrics, is today part of Thermo Electron and has continued its technology driven legacy by introducing countless improvements to its original concept. Thermo Electron’s latest offering in online Prompt Gamma Neutron Activation Analysis (PGNAA) for the cement industry combines leading-edge analytics with unprecedented installation flexibility in a package that has significantly lowered the installed cost.

Title: Mix design from Quarry to Cement
Author(s): Henrik Weisberg Andersen and Steen Tokkesdal Pedersen, F.L. Smidth Automation, Denmark, and Mette Herold, F.L. Smidth, Denmark, describe the benefits of the new QCX/BlendDesigner application module.
Synopsis:
- F.L.Smidth Automation has marketed applications for computerised quality control of stockpile, raw mill and cement mill production for more than 30 years. In that time close to 400 QCX/BlendExpert (formerly “Proportioner”) software modules of the QCX system have been supplied to cement plants all over the world. Whilst these applications provide quality optimisation at the plant floor level, they have so far not been targeted for design work at the quality management level.
  The new QCX/BlendDesigner application module is the quality manager’s toolbox for mix design from quarry to cement. It provides guidance on how to produce a new cement type, minimise the cost of raw materials, and examine the impact of new raw materials, additives, dust, fuel, etc.
  It has been developed using the Microsoft .NET platform. It is browser-based and may, therefore, be distributed via the local area network, the intranet or even the internet, without the need to install QCX client software.