| The mass stack of industrial solid wastes not only pollutes the ecological environment, but also does great harm to the human beings, as well as a waste of natural resources. It is of important significance to make comprehensive use of the waste, and change it to the profitable one.This research is to produce top rated split brick with extrusion technology, taking hematite tailings in western Hubei as main material, and clay or Kaolin as assistant one, by doing which to realize comprehensive use to solid wastes and improve the ecological environment.By using TG-DTA,SEM and XRD testing measures, we analyzed the characters,microcosmic features and pattern forms of hematite tailings in western Hubei,clay and Kaolin, and the result shows:it is feasible to produce new type split brick using hematite tailings in western Hubei, and the addition of clay or Kaolin can make its plasticity meet the need of extrusion. From the chemical composition aspect, all of hematite tailings in western Hubei,clay and Kaolin are feasible to produce tiles.This research has designed ingredients for G-series samples with hematite tailings and Kaolin, and N-series with hematite tailings and clay in, and also produced split brick for the both series. By using SEM and XRD testing measures to analyze the characters and microcosmic features, we get analysis on influential elements to the characters and reaction mechanism during the firing process of raw tiles. The result shows that the best ingredient of G-series is G2, to which the scale rate of hematite tailings in western Hubei is 60%, and its best firing temperature is 1140℃. To the samples of G2, the Wa value is 4.91%, the firing bending strength is 39.70Mpa,and the losing rate of bending strength after freeze thawing is 13.45%; and the best ingredient of N-series is N2,to which the scale rate of hematite tailings in western Hubei is 60%,and its best firing temperature is 1120℃To the samples of N2, the Wa value is 3.59%, the firing bending strength is 39.26Mpa,and the losing rate of bending strength after freeze thawing is 13.07%. Generally speaking, the characteristics of both samples of G2 and N2 exceed industrial standard of split brick.The main component of the samples of G2 and N2 are CaAl2Si2O8,SiO2 and Fe2O3,these are the sample's skeleton which increase the strength. From SEM chart, internal evenly with samples of quartz, needle bar granular calcium feldspar a1nd large glass phase. There are evenly distributed open pores and closed pores Inside sample, evenly distributed closed pores not only reduce the Wa, but also increase the resistance to freezing and thawing.The reaction mechanism during firing process of raw tiles:when the firing temperature achieves between 900℃and 100℃, the flux K2O,Na2O and CaO form low eutectic with MgO and SiO2; along with the rising temperature, CaO,Al2O3 and SiO2 react to be anorthite (CaAl2Si2O8), and the rest SiO2 reacts to beα-quartz.Based on the small test, the N2 ingredi-ent is chosen to the pilotscale experiment, and gets success. The best technical parameters in the pilotscale experiment:the best mustiness time is 3 days; the best drying method:4 hours with a temperature of 30℃, and 5 hours with a temperature of 60℃; the best firing method:keep the temperature for 30min at a increasing speed 2℃/min from 100℃to 200℃,300℃,700℃,800℃,till 900℃, and keep the temperature for 60min at the highest temperature 1100℃, after which the product has a water absorption of 3.50%, and it also has a bending strength of 30.24MPa and 28.25MPa before and after freeze thawing, with a losing rate of 6.58%. the characteristics of the product achieves the industrial standard of split brick. Besides, we discussed the technical problems appeared in extrusion%drying and calcinations, and get the solutions.We've done an analysis on the technology and economic indexes in the project of producing split brick using hematite tailings in western Hubei, and the result, based on its production chain project investment payback period and rate of return, shows that this project is feasible and profitable, which is of high economic and social benefit as well as risk resistance capacity.
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