الفهرس 
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Abstract
This thesis was carried out to investigate the potential to improve productivity by optimizing the grinding circuit, measure cement fineness by different fineness indicating parameters, obtain the separator efficiency under different separator speeds ,apply the Markov chain theory to simulate clinker grinding in a closed circuit and conduct numerical simulation and analysis of the grinding circuit parameters, determine the effect of adjusting parameters on the specific surface area and particle size distribution of the final product using Markov chain model.
Field experiments were carried out tomeasure the fineness of cement through different tests; Sieve Analysis of the fresh feed mix and air permeability test (Blaine test) of the final product .The Particle size distributions (PSD) of the three separator streams were obtainedvia Laser light scattering technique. All experiments were done at three different separator speeds.In addition, data regarding the improvements in the closed circuit after installation of high efficiency separators (HES) was alsocollected.
The results of the field experimentsshowedthat all the fineness indicating and Tromp curve parameters were consistent with the testing conditions ,also the separator showed normal separation at all speeds.The data collected showed that installation of high efficiency separatorsimproved the production rate and quality and decreased the energy consumption. Results of the field experiment were then utilized to identify the model’s parameters.
The Markov chain theory was introduced to describe the processes of grinding, classification, and particle transport in a closed finish mill circuit.It was utilized to allow calculation of all parameters of continuous grinding process in a mill.
The parameters of the Markov chain model were successfully identified, then these parameters were held constant and the different operational regimes were simulated. The simulation showed that the specific surface area and the 45 μm percent passing values derived from the model-calculated size distributions were consistent with the corresponding testing conditions.
Using the identified Markov chain model, the ideal grade efficiency curve was simulated and analyzed.Simulation showed that PSD followed the shape of ideal separation, the specific surface area increased and the calculated 45-μm sieve passing value was 100% indicating that all the final product was finer than the cut size.
The model simulated the fresh feed rate adjustment effect on PSD and specific surface area.The response of the circuit to the change in the fresh feed rate was in agreement with the nature of the classification process.
If a certain shape of the PSD of the final product is desired, the combination of adjustments in the parameters can be simulated in order to achievethat shape.These adjustmentscan improve the target performance characteristics of cementthrough enhancing the levels of fineness of the final product and optimizing the shapes of PSD.
Incorporation of HES saves energy by preventing over grinding of the finer particles and controls the product quality through improving the fineness of the final product.
This thesis was carried out to investigate the potential to improve productivity by optimizing the grinding circuit, measure cement fineness by different fineness indicating parameters, obtain the separator efficiency under different separator speeds ,apply the Markov chain theory to simulate clinker grinding in a closed circuit and conduct numerical simulation and analysis of the grinding circuit parameters, determine the effect of adjusting parameters on the specific surface area and particle size distribution of the final product using Markov chain model.
Field experiments were carried out tomeasure the fineness of cement through different tests; Sieve Analysis of the fresh feed mix and air permeability test (Blaine test) of the final product .The Particle size distributions (PSD) of the three separator streams were obtainedvia Laser light scattering technique. All experiments were done at three different separator speeds.In addition, data regarding the improvements in the closed circuit after installation of high efficiency separators (HES) was alsocollected.
The results of the field experimentsshowedthat all the fineness indicating and Tromp curve parameters were consistent with the testing conditions ,also the separator showed normal separation at all speeds.The data collected showed that installation of high efficiency separatorsimproved the production rate and quality and decreased the energy consumption. Results of the field experiment were then utilized to identify the model’s parameters.
The Markov chain theory was introduced to describe the processes of grinding, classification, and particle transport in a closed finish mill circuit.It was utilized to allow calculation of all parameters of continuous grinding process in a mill.
The parameters of the Markov chain model were successfully identified, then these parameters were held constant and the different operational regimes were simulated. The simulation showed that the specific surface area and the 45 μm percent passing values derived from the model-calculated size distributions were consistent with the corresponding testing conditions.
Using the identified Markov chain model, the ideal grade efficiency curve was simulated and analyzed.Simulation showed that PSD followed the shape of ideal separation, the specific surface area increased and the calculated 45-μm sieve passing value was 100% indicating that all the final product was finer than the cut size.
The model simulated the fresh feed rate adjustment effect on PSD and specific surface area.The response of the circuit to the change in the fresh feed rate was in agreement with the nature of the classification process.
If a certain shape of the PSD of the final product is desired, the combination of adjustments in the parameters can be simulated in order to achievethat shape.These adjustmentscan improve the target performance characteristics of cementthrough enhancing the levels of fineness of the final product and optimizing the shapes of PSD.
Incorporation of HES saves energy by preventing over grinding of the finer particles and controls the product quality through improving the fineness of the final product.