With the ever-increasing demand for quality products and stringent environmental policies and regulations, today’s manufacturing sector has been challenged like never before to put forward the right operational and business framework to achieve productivity with optimising cost, whereas consistently maintaining the quality of the end product.

The onset of a booming economy, calls for a better and sustainable infrastructure good housing and better connectivity across cities. Pertaining to the present scenario demand for cement is inevitable and the role of cement industries is as crucial while catering to the cement demand with the quality product they have to increase the productivity and have adhered to all the industrial rules and regulations. FLSmidth realises the optimal need and requirements and has been a preferred supplier of global cement plants for more than 135 years. The QCX Automation system by FLSmidth and has been a preferred solution for cement manufacturers globally seeking high standards of quality.

QCX
QCX, the acronym stands for quality control using computers and x-ray’s, is a solution for the cement and the mineral industries that has benefited in maintaining the quality standards consistently for years. QCX is equipped with predictive modeling, smart integrated technology and process oriented control philosophy that automates a total process of quality control, start from the right sampling till the measurement, logging and a right control action to process.

To further strengthen the system capabilities, QCX version 8 has been developed and released in 2014 commercially. With over 1,000 QCX products sold worldwide, it shows the quality of the solution and an immense history behind the journey of the QCX solution. The QCX product portfolio as a wide extends from optimising the raw material from the quarry to the analysis the final cement product from the packing discharge, which is completely automated thereby providing consistent quality 365 days a year, 7 days a week and 24 hours a day with very minimal human interference.

The following QCX products are commonly found in the cement industries that cater the needs of efficiency, productivity, cost saving and safety of the equipment and personals;

• QCX Manager
• QCX Blend Expert – Pile and Mill
• QCX Autosampling
• QCX Robolab

The QCX product mentioned above support quality control at all relevant stages of cement production in a single, integrated system and with the combined FLSmidth’ s extensive experience in the cement plant process control, incorporates in-depth understanding in process environment and the need for a faster and reliable analysis results in every stage of the cement process.

QCX history
It all began in 1969 when FLSmidth installed a process computer and an x-ray analyser at the Danish Cement Plant in Aalborg. The process computer was used as a data logger, and to calculate new feeder set points, based on the analysis of the rawmix control sample. In those days, it was very advanced to have a process computer and X-ray on a cement plant, so the following was called QCX-System;

Q = Quality
C = Computer
X = X-Ray
Today, the QCX have more than 40 years of development across multiple hardware platforms and a comprehensive base of installed systems has made the QCX system the front-runner in the cement industry. The QCX systems ensure that the processing laboratory delivers safe, efficient and accurate analysis quickly and with fewer laboratory operators as possible. The advanced, user-friendly system can be tailored per the specific cement production needs, including special cement fuels and support continuous 24 x 7 operations.

Automated laboratory solutions from FLSmidth are setting new industry standards in terms of ease of use, flexibility, reliability and scalability. The error from sampling is 10-fold bigger than the error originating from the analysis from the XRF.

So obviously, the maximum investment in automation should be in sampling, but, the more investment is made on sophisticated analysis equipment and less on proper sampling.

Therefore, the QCX products installed in a cement plant would typically follow the four steps:

• Step 1: Sampling – Eliminate the sampling error
• Step 2: Sample Preparation – Eliminate the sample preparation error
• Step 3: Analysis of the Sample: Eliminate the Analytic errors
• Step 4: Corrective action: Eliminate the judgmental errors

Step 1: Sampling: QCX V8 / Autosampling from FLSmidth controls automatic sampling and pneumatic transport of the sampled material from the process areas to the laboratories for further process of the collected representative samples. Automated sampling results in samples being taken at the correct time intervals and ensures;

a.Sampling quality is representative of the larger production;
b.A fail-safe sample identification including time stamping
c.Minimal sample to sample cross contamination
d.Automated composite/average sampling.
e.Fast turnaround time from sampling to analysis
f.Complete sample traceability
g.Improved quality control;
h.Optimisation and prioritisation of the overall sample taken schedule
i.Any time sample call for additional/verification test providing flexibility to the operators.
j.Efficient people and time management, allowing the use of operators in other areas.
k.No health and safety issues for personals
l.Improved and faster troubleshooting and maintenance through informative faceplates by providing the status of the equipment
m.The pneumatic transport system has been employed for fast transportation in harsh conditions since the 1960’s. FLSmidth has been involved since the early days and has gained leadership and prominence in the market through installation and execution of 100s of projects globally
n.Sampling equipment for powder granulates lumpy materials can be collected and sent automatically to the laboratories thereby ensuring a fully automated process.
o.The advanced programming logic ensures cost-effective engineering and reliability of the equipment and the high availability of the system.
p. World wide support by a dedicated team around the clock.

QCX/Autosampling V8 can be seamlessly configured in any work process and customised according to the specific requirement if raised. FLSmidth has both semi- and fully-automated sampler for all the cement plant applications – from the raw material to cement dispatch including an all new and improvised hot Kiln outlet sampler for a very fast clinker analysis and thereby fast feedback to chemical changes introduced in the kiln. FLSmidth has over 200 QCX Autosampling systems installed worldwide providing a greater quality control and production capabilities setting them apart from the rest of the cement plants.

Step 2: Sample preparations: QCX/Robolab
is a fully automated, robotics-based laboratory concept with a very high degree of flexibility for individual solutions. The concept is based on sample preparation and analysis equipment arranged in a circular configuration around a powerful industrial robot. Analytical instruments are located in an adjoining room, typically separated by a glass wall or integrated into the robotic circle. For the first mentioned set-up, sample loading takes place via transport belts and special sample loaders. These components may be eliminated when analytical equipment units are directly placed in the robotics circle.

Sample preparation and analysis equipment are sub-supplied by leading equipment suppliers, while FLSmidth automation as the system integrators designs the total automation solution and produces the QCX/Robolab software, engineered to the project specific configuration. Depending on the automation specifications existing equipment may be integrated. The system is software wise delivered as a completely integrated system, with efficient commissioning in mind.

Samples arrive either via the connected automatic sample transport system or via manual/Semi-automatic transfer points into the robot cell. Bar code scanning for identification of incoming samples is supported.

A wide range of sample preparation and analysis task can be automated by the QCX/Robolab. Multiple robot cells or individual robot cells – can be controlled from one QCX server, and there are no limitations as to the number of interfaced equipment units. Typically applied automation tasks comprise:

• Crushing (and drying)
• Splitting and dosing
• Pressed powder and/or fused bead preparation for X-ray analysis
• Specific surface (Blaine)
• Particle sizing
• Colour analysis
• Combustion analysis for carbon sulphur / H2O determination
• Composite sample collection

For automation of cement plant production laboratories, the standard robot model used has a load capacity of 5-7 kg and a reach of 1.8 m. Automation projects in the other mineral industries such as mine exploration sample preparation and sample preparation for ship loading/mining grade control, etc. often involves handling of large, bulky sample portions. This implies the use of robot models with load capacities in the range 30-200 kg and a reach 2.5 to 3.0 m. Multiple robots with exclusive overlapping working are also possible.

The Robolab at Aalborg Portland cement installed in 1993 is still in operation tirelessly after even two decades with the same vigor. Aalborg Portland Cement, the Robolab provides:

• 24 hours around the clock
• +98 per cent system availability
• No Monday morning blues
• Same ‘operator’ on duty means: High consistency and quality 0 of sample prep and analysis.

The First Robolab in India was installed and commissioned in 2008 at Sagar Cement, Mattampalli, Suryapet Dist, Telangana. QCX/Robolab features include:
1.Fully automated sample preparation with manual or semi-automatic equipment.
2.Fully automated transport of samples between equipment units
3.Very flexible in terms of the number and types of equipment handled by the robot.
4.The typical throughput capacity of 10-20 samples per hour or higher dependent on configuration.
5.Built-in manual back-up, since all equipment can also be handled by a human operator.

Step 3: Analysis of the sample: The wet analysis method is still been used in the cement industries till date as a reference at times, with the, increase in production capacity and the ever increasing demand the need for faster analysis and feedback for better quality was in the making. Elemental analysis online applications (PGNAA or XRF) for raw material mix control have been established and acknowledged in the market since the early 1990es. These latest technical developments resulted in improvements (e.g. a reduction in variability of the controlled parameters0 of the mix quality to the levels which would not have been achievable without the online analysers and the XRF’s.

With the combination of the QCX/ Autosampling, QCX/Robolab and the QCX/BlendExpert the faster and on-time arrival of the samples with a consistent sample preparation gives the added advantage to the analysers analysis to be more accurate and eventually a better-quality product. The WDXRF is the standard for lab instruments on cement plants. On cement plants, EDXRF is typically used for online applications or for fast C+S analysis for cement mill samples. FLSmidth QCX system can be integrated with many WDXRF and EDXRF suppliers per the site or customer requirements.

Solutions for at-line free lime analysis are also available and have been out there for many years. The Cement grinding department is the focus area for the next wave of online analysis solutions. The most applied application here is the laser particle sizing installed with the main objective of power savings. However, the strong market trend to apply online/at-line analysis techniques in the cement production process also comprise Blaine, carbon-sulphur (C/S), LOI and XRD. To meet this market demand, FLSmidth automation offers a complete range of solutions, which includes sampling, sample transport and preparation, and analysis.

Step 4: Corrective action: With the faster and on-time arrival of the representative samples to the laboratory via the QCX/Autosampling and reliable and faster sample preparation via the QCX/Robolab the analysis results from the analyser should be put into use for the corrective actions and the QCX/Blendexpert is the right choice for the cement industries. The QCX/BlendExpert controls the proportioning of the raw material feed to the stockpiles, raw mills and cement mills or other process blending system to obtain the desired chemical product quality with respect to chemical constraints, process constraints, material costs etc.

Complemented by functionality for quarry operation planning and chemical mass balance and mix design calculations the QCX/Blendexpert suite of application modules support quality optimisation from the quarry to bagged cement.

The typical application of QCX/Blendexpert is material feed set-point control based on periodical analysis of representative samples of the controlled material stream. The analysis data are received automatically from the laboratory XRF spectrometer and/or from the online XRF or PGNAA analysis devices. Upon completion of an analysis cycle, new feeder set-points are calculated and automatically positioned. The control algorithms support off-line control modes (e.g. manual set point positioning or operator inserted analysis/production figures).

In addition, the new developed FlSmidth high-level control system, QCX/Blendexpert V8, eliminated the need for specific sampling and analysis of raw materials into the feeder. In addition, it displays and manages dynamic bias correction from any online analyser in the process. Customer having the QCX/Blendexpert high-level control system are benefited with:

• Improved Chemical control results in stability of operations and delivers fast payback on investment
• Lower fuel consumptions in the kiln and preheater.
• Reduced equipment wear and longer lifetime of mechanical parts
• Less thermal stress is a direct benefit of the QCX/Blendexpert’s chemistry control.
• Up to 60 per cent lower standard deviation of LSF
• No need for sampling, sample preparation, and analysis of raw material ? chemical values are accurately estimated.
• Reduced need for blending silos.
• Higher alternative fuel substitution rate.
• Steady 24 x 7 control philosophy.
• New, intuitive user interface, providing an easy overview of ‘next step’ operations.
• Fast troubleshooting of material feeders through direct monitoring of feeder operation.
• Improved accuracy and enhanced benefits from the online analysers through dynamic bias correction.
• Best use of raw materials and additives, leading to cost savings.
• Optimal control of material blending during upset conditions – no need to switch to manual control.
• Existing users of QCX/Blendexpert V7 will enjoy significant improvements when upgrading to V8.

Challenges faced
Cement producers face many challenges and the QCX/Blendexpert helps them to overcome. QCX/Blendexpert optimise raw material blending to meet high-quality targets. The upshot is reduced fuel consumption and stable kiln operation. This, in turn, leads to less thermal stress on kiln parts, such as lining, resulting in fewer and shorter kiln stops.

Tight control of raw material blending negates the requirement for expensive blending silos. Silos can be considered storage buffers only and this dramatically reduces the need for capital expenditure. QCX/Blendexpert also compensates for poor functioning blending silos on existing plants.

QCX/Blendexpert is a world class control system, meaning the complex task of controlling varying raw material qualities is no longer manual. QCX/Blendexpert boasts a simple and intuitive user interface, making it easy for operators to use.

Alternative fuels are becoming an increasingly important option for cement plant to reduce their CO2 footprint. With QCX/Blendexpert Kiln operation is more stable and this enables stricter control emissions. In addition, the use of alternative fuels, without jeopardising clinker quality, opens new possibilities for many cement plants.

Results achieved with the QCX/BlendExpert V8
While high-frequency online analysers can result in improved control performance, automatic sampling and sample preparation result in more accurate and precise analysis. By integrating these analysis techniques QCX/BlendExpert delivers the vital link to attain substantial quality improvements.

FLSmidth has continuously demonstrated that QCX/BlendExpert provides considerable control improvements compared to manual set point control. QCX/BlendExpert has a proven track record to maximising performance improvements.

Quality improvement
Previous versions of QCX/BlendExpert software performed well. However, with the new QCX/BlendExpert V8, cement producers have seen a reduction of lime saturation factor (LSF) standard deviation of 60 per cent compared to earlier versions.

Auto correction of online analyser
Some plants trust their online analyser to provide correct analysis, however, this is not always the case. QCX/BlendExpert advanced process modeling takes all material process delays into the equation and compares between the quick online analyser results with a correct analysis from the laboratory XRF. Dynamic bias correction of the online analyser is based on this. This bias correction significantly enhances the value of the online analysis.

Maximum use of AFR
Alternative fuels are becoming important for most cement plants. Using by-products provides waste management options that can be economically viable, regionally available and environmentally sound. Some alternative fuels generate chemical constituents, such as alkalis or chlorides, that must be considered in the equation when designing the chemical targets of the cement.

QCX/BlendExpert is designed to handle these important factors.

• Less Homogenising requirements
• When engineering a cement line, eliminating or reducing the size of the homogenising equipment is often an important factor. This puts added pressure on blending the raw materials.
• The QCX/BlendExpert proves that it’s possible to operate a cement line with a direct feed from the quarry to the mill or from the mill to the kiln.
• This feature is effective when an existing homogenising silo is not functioning well and not blending to the desired factor.
• No need for sampling and analysis of raw material
• The raw material estimator had proven to be as accurate as the physical samples taken from the raw materials, thus eliminating the need for this manual process.

QCX/BlendExpert features:

• Automatic Feeder Offset correction
• Automatic handling of feeder starvation
• Multiple materials per feeder
• Silo Estimation
• Chemistry designer tool

QCX reporting
The QCX modules are designed to operate together with the QCX reporting. The modules generate the reports for shift, day, month and yearly which includes the chemical performance and the KPI of the equipment and the overall laboratory performance. The OCX Reports offers approximately two years of data storage capacity and manages all reports as well as trend curves. The extensive and flexible report generation and graphic presentation facilities provide:

• The configuration of general QA reports.
• Configuration of customer specific reports
• Auto-generation of reports.
• Automatic scheduling of reports.
• Report availability on the QCX website
• Report availability via email.
• The configuration of trend packages.
• Fast trending chemical results
• Trending up to 10 sample analyses in one view.

Alarm Handling: Sampling, analysis or equipment alarms and non-critical events are logged in-order-for the laboratory personnel to keep track of ‘bad’ samples and other important events, such as maintenance scheduling. Event historian: And event historian keeps track of alarms and events. The live events list and historical events are tracked and recorded. This record is useful should there be discussion regarding events or alarms or a need to review them. Easy to install, easier to use: FLSmidth has combined more than 40 years of experience in material proportioning in the development of the QCX modules in both software and hardware. The enhanced software and the hardware offer significant improvements for all cement plants. It has been designed using the latest control technologies and can be installed on a standard standalone PC, Physical or virtual. It has an easy to interpret graphical interface and advanced alarm and trend capabilities.
FLSmidth’ s eight-step implementation process

• Project planning: An FLSmidth project manager prepares a start-to-finish strategy.
• Client process interview: FLSmidth engineer interview the client regarding the blending control strategy, process models and other required details.
• Application Design and process strategy review: FLSmidth designs the right solution based on the site interview.
• Primary system commissioning; Commissioning is completed and the system is implemented and monitored on site.
• Operator and Super-User training: FLSmidth representatives train operators in the new system.
• Remote monitoring and fine-tuning: As the final part of commissioning. FLSmidth makes small adjustments to the system remotely – this requires a nternet connection to the system.
• After sales service: after commissioning is completed, FLSmidth transitions the project to the service phase.
• Establishing long-term support: FLSmidth can support the system with software updates and ensures it runs as efficiently as possible.