Optimal raw material control
FLSmidth’s QCX/BlendExpert™ suite of applications supports product optimisation from quarry to delivered cement. Finnsementti was the first test site for the latest generation, upgrading from QCX/BlendExpert™ V7 to QCX/BlendExpert™ V8 in 2015, in order to prioritise raw material quality. Achieving better than expected results, Finnsementti has experienced a positive shift in performance, cement quality and customer satisfaction.
When the team turned on the new V8 system, it became immediately clear that this was a very good system.
Finnsementti, part of the global building materials group CRH, is the only Finnish manufacturer of cement and has more than a century of experience producing cement. The majority of Finland’s cement demand is produced at Finnsementti’s plants in Pargas and Lappeenranta. The Finnsementti Lappeenranta plant does not have systems for the pre-homogenisation of raw materials. A conveyor delivers raw material from the quarry directly to the raw mill silo. No homogenisation piles are used in the operation. In the past this meant the production team were
not receiving analysis of their raw materials, which was affecting their end product.
They knew that this had to change. They began a journey of improving processes to a point that their quality was comparable to if they had pre-homogenisation systems in place. They have now achieved these high quality levels at a significantly lower cost compared to establishing pre-homogenisation piles.
Over the years, Finnsementti invested in a number of quality improvements:
- In 1967 and 1991 the Lappeenranta plant installed FLSmidth’s Pfaff samplers which take raw meal samples every hour and kiln feed samples every two hours.
- In 2003 the plant supplemented their existing samplers with an FLSmidth QCX/Autosampling system.
- In 2003, the plant invested in FLSmidth QCX/BlendExpert™ V7 to control the raw material feeders and the blending.
- In 2013, to enhance the sampling programme, they invested in a PGNAA (Prompt Gamma Neutron Activation Analyser) before the raw mill to provide minute-by-minute measurement of the entire stream.
Finnsementti was on a journey of renewing customer confidence by improving the quality of their end product, which meant first improving raw material quality and blending processes. Processes were improving, however, there was still significant scope for further improvement. The goal of installing QCX/BlendExpert™ V8 was to reduce kiln feed LSF standard deviation to <1.
Defining the project
In 2015, FLSmidth invited Finnsementti Lappeenranta to be the first test site of Version 8 (V8) QCX/BlendExpert™, which had been in development for several years. The project involved installing the new QCX/BlendExpert™ V8 software at the Lappeenranta site on a new PC as well as installing the drivers for the XRF (X-ray fluorescence) spectrometer and the PGNAA.
Finnsementti needed more stable operations that would lead to better clinker quality, fuel savings and improved systems to detect production disturbances. QCX/BlendExpert™ V8 was an ideal choice of software to provide this solution through strict quality control and chemical optimisation.
QCX/BlendExpert™ is a world-class high level control system where the complex task of controlling varying raw material qualities is no longer manual. The user interfaces are designed so that operators are only informed of high level information, such as process disturbances.
Due to the process setup with no pre-homogenisation, Finnsementti operators were accustomed to closely monitoring every change in the raw material department and occasionally making manual interventions. The operators were hesitant to migrate so quickly to a system that made all decisions on their behalf. FLSmidth adapted the user interface to suit the needs of Finnsementti operators so that the information about QCX/BlendExpert™ decisions could be provided to them as per their old system.
Since first implementing the new system, Finnsementti operators have come to rely on QCX/BlendExpert™ V8 to make informed and intelligent decisions for them, now referring to the LSF, SIM and ALM green tick mark as their most valuable first point of information.
For Finnsementti Lappeenranta, the raw material estimator of QCX/BlendExpert™ V8 has proven to be as accurate as the physical samples taken from the raw materials, thus eliminating the need for a sampling of the raw materials. Their original goal with QCX/BlendExpert™ V8 was to reduce kiln feed LSF standard deviation to <1. This goal has the physical samples taken from the raw materials, thus eliminating the need for a sampling of the raw materials. Their original goal with QCX/BlendExpert™ V8 was to reduce kiln feed LSF standard deviation to <1. This goal has now been achieved and, with some further fine tuning, their Quality Engineer is confident of achieving a more ambitious goal of 0.6. They have attained a more stable operation with fuel savings and enhanced clinker quality and strength. They can also immediately detect and address the smallest disturbances, which was not possible previously. This allows for more efficient operations.
The improved processes have resulted in an increase in positive feedback from customers regarding cement strength, which has improved the reputation of the business. The operators are now at a point where they can start fine tuning the process - having complete control when before they felt like the process was running them.
Cost efficient additive control and reduced fuel consumptionFinnsementti Lappeenranta uses more environmental friendly and cheaper alternative fuels. These include refusederived fuel (RDF) in the calciner and waste oil, mixed with traditional fuels, in the main burner. With QCX/BlendExpert™ V8 the kiln feed stability and burnability has improved. The upshot is more stable kiln operation and a better fuel split between the main burner and calciner. In total, the alternative fuel rate is >55%. This saves the plant money. Finnsementti Lappeenranta uses more environmental friendly and cheaper alternative fuels. These include refusederived fuel (RDF) in the calciner and waste oil, mixed with traditional fuels, in the main burner. With QCX/BlendExpert™ V8 the kiln feed stability and burnability has improved. The upshot is more stable kiln operation and a better fuel split between the main burner and calciner. In total, the alternative fuel rate is >55%. This saves the plant money.
Immediate response to feeder starvation
From time to time, during winter, the Lappeenranta plant experiences frozen raw materials, which are prone to stick in feeders. Now, with QCX/BlendExpert™ V8 and its easy-to-see “green tick mark” indicating if all chemical constraints can be met under current conditions, the operators can immediately detect an error with the process chemistry. The problem can be eliminated straightaway with no need to wait for a laboratory sample.
The new raw material estimator in QCX/BlendExpert™ V8 predicts if the plant can meet the LSF, ALM and SIM targets. The system alerts operators if a feeder is in starvation so they can immediately activate process operators to clear the blockage in the given feeder. This has been a great benefit for Finnsementti, saving them from producing off specification clinker.
We have experienced excellent service from FLSmidth during this period - always receiving fast replies and very competent assistance from people who know the issues in a cement process.