Abstract This research was an attempt to use the currently available activity coefficient methods with universal sets of parameters to simultaneously predict ternary liquid-liquid equilibrium data. The focus of this research was to calculate phase equilibrium data within fair error using set of Parameters obtained from the above-mentioned models. The significance of this work is to study the liquid-liquid phase equilibrium of the ternary system at several temperatures and to test the capability of the various equilibrium models to correlate these data. A series of liquid-liquid equilibrium measurements were performed by changing the composition of the mixture.The prepared mixtures were placed in the extraction vessel and stirred for 2 h and then left to settle for 4 h. Samples were taken by a syringe from both the upper phase and lower layers. Both phases were analyzed using gas chromatography equipped. Liquid-liquid equilibrium for the ternary system acetonitrile + benzene + n-heptane was measured at 298,313,333 K. The results were used to estimate the interaction parameters between each of the three compounds for the NRTL and UNIQUAC models as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models. The UNIQUAC equation was the most accurate model in correlating the overall equilibrium compositions of the studied system. NRTL models satisfactorily predicted the equilibrium compositions. In each of the mentioned the ternary system, the calculated and experimental data were compared. The root mean square deviation (RMSD) between the observed and calculated mole percent for NRTL, UNIQUAC was 1.44%, 1.35% for acetonitrile + benzene + n-heptane
عماد الدين محمد الزغداني (2014)

Rotary Kilns are one of the most widely used pieces of processing equipment. They are used for drying or calcinng a variety of products including sand, aggregates, limestone and food products. Heat transfer in rotary kilns encompasses all the modes of transport mechanisms, that is conduction, convection and radiation. In rotary kiln operations the chemical reactions in the bed required high temperatures. The energy to raise the temperature and drive endothermic reactions is from the combustion of a range fuels such as heavy oil, natural gas, coal and more alternative fuels. Heat transfer from the gas to the bed is complex and occurs from the gas to the bed surface and kiln wall to bed surface via conduction, convection and radiation. The study concerned to perform a mathematical modeling to simulate of the heat transport in the cement rotary kiln to predict the temperatures at internal and external wall surfaces of the rotary kiln to preventing many industrial problems through the operation process such as (loss of coating, red spots formation, ….) also to predict the optimum range conditions for safe operation. The results obtained show that, the predicted data using a mathematical model satisfied with industrial data for burning zone. The study showed a derived mathematical model can be used with a good reliability to description of heat transfer in burning zone of rotary cement kilns.
abdulati Elhadi tater Elalem, Mohamed A.E. Aldeib, Hesham G. Ibrahim(5-2010)

Abstract This study is to develop the specifications of the present cement products so as to comply with the quality and quantities requirements of the local market. The subject of this thesis is to present the results of a series of laboratory trials on a number of raw material mixtures prepared to produce moderate and high sulfate resistance cement at EL- Mergheb cement factory which currently produces ordinary Portland cement. At first, six different raw material sample mixtures were prepared from marlstone,marl and iron ore. The clinker (cement ) produced from these samples was within the moderate sulfate resistance cement ( MSRC ) specifications which mainly requires the tri calcium aluminate (C3A) to be less than 8 % by weight. The trial runs on other three raw material samples made that from mixing marlstone , clay , and iron ore produced clinker specifications that were out of those for MSRC namely, C3A is greater than 8 % . This means that the addition of clay to the raw mix prevents the production of cement with MSRC specifications. This was due to the high percentage of Al2O3 in the clay . The specifications of the clinker products based on these results , MSRC was successfully produced at the factory from raw material mixtures ( marlstone, marl and iron ore ) without any clay addition . Finally three raw mix samples were prepared from marlstone, marl, iron ore, and sand and tested in the laboratory to explore the possibility of producing high sulfate resistance cement ( HSRC) which requires C3A to be less than 5 % . The results of these laboratory trials showed that when the sand in the raw mix is kept under 1.80 % , the produced clinker specifications are within those of HSRC. The permission to carry out these trials in the factory is underway. The expected economic benefits from producing both MSRC and HSRC is highly feasible. Both types will be sold in local market without any additional operating or capital costs .
صالح محمد صالح (2013)