Incorporating non-ferrous slag from Zn smelter as an alternative raw material in clinkerisation-An Industrial experience
Mohan MedheR M SahuManish KuchyaV K JainSubrato Chowdhury
Central R&D,UltraTech Cement Ltd.
摘要：Currently,Indian cement industry is having option of increasing production of blended Portland cements using supplementary cementitious.materials and utilizing raw materials principally derived from industrial by-products,such as various siags,for responding rapidly to the perceived societal need of sustainability in manufacturing practice and green development,It will not only help in solving the environmental pollution problems associated with the disposal of these wastes but also help in conservation of natural resources which are fast depleting.However,careful analysis of the industrial practice reveals that majority of the commercial manufacturers rely more on using supplementary cementitous materials/blended coment route for increasing sustainability while very limited population try and utilize industrial by products while clinkerisation.Additionally,it can also be observed from scientific literature that although numerous industrial by-products are demonstrated to be useful for clinkerisation at laboratory scale,the data seriously lacks in any information about experiences of such materials on industrial scale.Consequently,absence of data related to industrial wastes with respect to material handling and grinding,clinker grindability,operational problems while clinkerisation in kiln and effect on sp.heat consumption,influence of minor constituents on cement properties,etc.,largely deter manufacturers from using such wastes since economic consequences related to disturbances in quality/productivity remains a concern.For achieving fuller potential of industrial wastes in cement manufacturing more and more plant experiences and data are desired,which may reduce the inhibition.Present paper exemplifies the approach by elaborating on a case study on utilization of non-ferrous slag from Zn smelter as a raw mix component from a detailed lab-scale investigation involving physico-chemical and mineralogical characterization,burnability study,etc.followed by experiences about 2 months full scale plant trial operating at 5,500 Tonnes/day for addressing practical concerns.The study establishes practicality of replacing one of the raw mix additives,namely Laterite using Pb-Zn slag,based on plant observations while using about 10,000 Metric Tonnes of this slag with dosage rate in the range of 1.5- 2.8%with limestone stock pile LSF levels of 115-116,in terms of its impact on raw materials grinding,pyro-processing（burning）,cement mill performance and product quality.Although kiln operations were fairly steady without any process problems,material hardness of the given slag was observed to affect raw mill productivity marginally by around 6 tph for maintaining given fineness.Introduction of Pb-Zn slag in the system was observed to be almost neutral in terms of specific heat consumption（kcal/kg clinker） and clinker liter weight.Use of Pb-Zn slag did not cause any refractory related problems during continuous operations over a period of two months.Cement qua
The 14th International Congress on the Chemistry of Cement（ICCC 2015）