Why You Should Choose COSMA for On Line
Process and Quality Control

Why COSMA?
Why XRD?
Why continuous analysis?
What is analysed?


Why COSMA?
COSMA measures the quantity of minerals present in cement and other dry materials continuously and in real time. COSMA is installed in the plant near the product stream to be analysed, and uses X-ray diffraction (XRD) and Rietveld techniques to deliver an accurate quantitative analysis of approximately 250kg of material per day. COSMA forms part of the plants control system (PC based or DCS), supporting process control via the plant?s expert system or the operator interface system.



COSMA Leamington Auger COSMA leamington room

COSMA curved detector




Why XRD?
The mineralogy of cement and clinker, complimented by their chemistry, plays a vital role in determining the performance of a cement plant, as well as cement product. For example, the burnability and grindability of materials, and the strength development and setting times of the final product depends on the minerals present in those materials.

X-ray diffraction (XRD), together with Rietveld analysis, measures the quantity of important minerals such as C3S, C2S, C3A and C4AF, which directly influence the performance of clinker and cement. It is now widely accepted that direct mineral analysis by XRD is superior to chemical analysis by such methods as X-ray fluorescence (XRF) and the calculation of theoretical mineralogy using Bogue equations for the analysis and control of the cement production process.

Graph of Gypsum States and Cement S03 by XRD

XRD Free Lime Trend

Why continuous analysis?
Continuous analysis of a flowing stream of material has several benefits.

First, COSMA analyses an extremely large sample in comparison to laboratory based techniques. COSMA analyses as much material in 5 minutes as a laboratory-based automated XRD analyser examines in 24 hours. This increases confidence in the result and greatly reduces the potential for sampling errors associated with a small sample tablet analysed in a distant laboratory.

Second, COSMA is a Quality Control tool rather than merely a Quality Assurance tool. COSMA delivers its analysis in real time so that the information can be used in an automatic control loop to manage kiln burning conditions, cement mill operation, weighfeeder operation, or other aspects of plant operation. Using distant laboratory-based equipment the lag time between taking samples and delivering analytical information is too great for automatic control, particularly if complete mineral phase composition information is required.

Third, COSMA provides a trend of analytical information in the same way that temperature or pressure can be trended. This means that control decisions can be based on trended information rather than single analysis points, which makes for a highly robust control system using mineralogical information in the control strategy.

With laboratory systems, even automated ones, the lag time between sample collection, preparation and analysis is always too great for the implementation of truly automated control actions. With continuous input from COSMA, needed adjustments can be made at the time when variations actually occur instead of some time after their effects are already a matter of history and any corrective action may be too late, or may cause other problems in the process.

What is analysed?
COSMA accurately and simultaneously measures the following minerals:

Clinker - C3S, C2S, C3A, C4AF, CaO and any other minerals of interest in clinker ground to 20% +45micron. Identification of alpha, beta and gamma phases of some of the clinker minerals is also possible, allowing relationships to be developed between the phases in clinker, the kiln conditions and the performance of the product.

Cement - C3S, C2S, C3A, C4AF, CaO, Ca(OH)2, CaCO3, CaSO4.2H2O, CaSO4.1/2H2O, CaSO4 and other crystalline minerals are analysed in cement flowing directly from the finish mill.