Investigation Into Quality Advantage Of Cement Clinker As Produced With A High Solid/Gas Ratio Preheating And Calcining System (XDL System)

With the consumption of high-quality limestone, and large numbers of low-gradelimestone raw materials and industrial waste into the discard, resource crisis becomesmore and more serious in our country.The sustainable development of the cementindustry needs to improve the performance of the clinker while a large number oflow-grade raw materials can utilize, reducing the production costs, and achieving goodeconomic and social benefits.The high solid/gas ratio preheating and calcining system(here after referred toXDL system)adopted the5stage cyclone-8cross material flow, the XDL suspensionpreheater and small volume decomposition furnace of low temperature, which madethe gas-solid contact area and contact time increased exponentiallycompared to anormal solid-gas handling system,and significantly improved the thermal efficiency ofthe preheater, apparent decomposition rate of the carbonate close to100%. Due togreatly improved the calcination temperature distribution of the rotary kiln, the coalusing proportion of kiln tail and head kiln up to8:2, which reduced the impact of ashlanding on the quality of clinker.In this paper, the clinker and fuel data of the high solid/gas ratio system inGansu-Sanyi, Yaobai of Shaanxi-Hancheng, Shaanxi eco-cement were investigatedcompared with ordinary solid/gas process ratio system in Shaanxi-Hanyu,Shaanxi-Shifeng,Qilianshan of Gansu-Pingliang to study effect of MgO on the clinkercompressive strength and flexural strength. Through comparative study on the calcination process of XDL system and thegeneral NSP system, such as the decomposition rate, calcination temperature, coal,MgO content of the clinker, the clinker quality superiority in a high solid/gas ratiopreheating and calcining system was analyzed.In this paper, various analyses (i.e. chemical analysis, XRD analysis, TG-DTGanalysis, BSE+EDS analysis and petrographic analysis) were carried out toinvestigate the properties of clinkers as produced with such magnesia-limestone in sixcement plants Northwest, China.Results as measured proved thata clinker productionline with a high solid-gas ratio system could be used to produce good quality clinkereven with high magnesium limestone as raw materials, and superior to a normal clinkerproduction line.