| It has been long time that the local white cement is difficulty to be applied into high-end construction markets. And the high-end market for building decoration is mainly occupied by the foreign brands. The main reasons given for this are that the product quality is poor and energy-consumption is high. Yet,the problems mentioned above are the result of a number of factors including small size of cement kiln, backward cooling technology and unsteady component in the local white cement production. Since 2012, School of Materials Science and Engineering at Nanchang University cooperated with Jiang Xi YS white cement co., LTD and developed a serious of new technology for the cooling of white cements, such as Distributing type of white cement cooling process and horizontal white cement clinker bleaching machine. Meanwhile they transformed an ordinary Portland cement production line with 1500 t/d to a white Portland cement production line with 1200t/d. As part of the renovation project work, the effect of the raw materials and cooling process on the energy consumption and whiteness will be mainly discussed in this paper.By analyzing the performance characteristics of raw materials, we confirmed the adaptability of the local raw materials as white cement raw material. We compared the property of petroleum coke with coal; the impact on the whiteness of cement was also analyzed. We probed into the problems when the petroleum coke was used in the process of production in pre-decomposed kiln and put forward replying the measure. In this paper, a new process for chemical removal of Iron from porcelain clay was developed. Emphases studied the effect on the whiteness and strength of cement under different cooling process and explored the mechanism of the differences. We also analyzed the effect of fineness on the whiteness of clinker and white cement.Experiments found that the Gujiang and Taihe limestone were high-quality calcareous materials, Wanjiashan and Zhumaqiao clay were easy to burn, and other mines of raw materials could be used in accordance with the production situation. By analyzing the characteristics of petroleum coke,we found that it could be used as burning fuel for white cement production, and it had no adverse effect on the clinker whiteness. Moreover, the petroleum coke was in the use of low cost. Aiming at the problem of high combustion ignition, high combustion temperature and high sulfur content, we tried to solve them by mixing biomass fuel materials, adding alkali materials. The method of chemical removal of iron from the porcelain clay can effectively improve the whiteness of the porcelain clay, and iron removal rate was 40.9%. Compared with air cooling and water cooling technology of white cement in the physical and mechanical properties, they were similar in the intensity of 3d and 28 d. Compared the clinker burn both in laboratory electric furnace and in YS, the whiteness of clinker under water cooling process was generally higher than that under air cooling process in 1~2 Hunter whiteness. There was no significant difference, and the difference mainly came from vitreous content and the Ca(OH) 2 content generated of mineral hydration. The whiteness of clinker increased with the increase of specific surface area, but the growth of whiteness was not the same rate as the fineness.When the specific surface area was 550m2/kg, the whiteness would not basically improve. The fineness had a greater influence on the whiteness of cement, when the specific surface area was 600m2/kg, the whiteness was basically in a state of saturated. |
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