Research On Using Desulphurization Dregs And Other Industrial Waste To Produce Ceramics

In this thesis, the fabrication of ceramic products using desulfurization slag, molybdenum mine tailings and other industrial waste as raw materials was studied. The chemical composition , mineral composition and thermal properties of desulphurization slag, molybdenum mine tailings and artificial stone powders were studied by XRD,TG-DSC,X-fluorescence elemental analysis,besides, the related properties of the products were characterized. The conclusions of the thesis are summarized as follows:1) Quartz–based molybdenum mine tailings with trace feldspar, mica and molybdenum can replace the feldspar and sand etc. as raw materials to produce ceramics. Using 30% molybdenum mine tailings and other clay materials can produce first-class sintered tile under the conditions of sintering between 1050℃and 1100℃for 1h , and its performance can reach the requirements of GB/T21149-2007"Sintered Tile".2)Adding 6% desulphurization slag of which the main component is CaSO3 to the experimental formula of 35% red mud, 35% yellow mud, 30% sand to produce sintered tile,its release rate of SO2 can be reduced from more than 90% to 56% under the conditions of switching atmosphere to oxidation atmosphere,changing the firing temperature from 1100℃to 1050℃and reducing the holding time from 2h to 1h.3)Using desulfurization slag to produce ceramics, when increasing the mCa /mS≥3 by adding waste stone powder can obviously reduce its release rate of SO2. Moreover, when adding 6% desulfurization slag and 10% calcic waste stone powder to the blank to produce ceramics, the calcium in the product mainly exists in the form of CaSO4 and CaAl2Si2O8 with no free CaO, so there is no affect to the quality of ceramic products. At this point, its release rate of SO2 can reduce from 56% to about 45%.4) Glazing the ceramic with calcic glaze can close the surface pores and absorb SO2. The efficiency of inhibiting the release of SO2 was enhanced with the increasing of calcium content in glaze. Calcium in the glaze layer mainly exists in the form of CaSO4 as well as glass phase, and the body-glaze combination is good. Moreover, replacing the sand with molybdenum mine tailings is also favourable to reduce the release rate of SO2 for the glass phase was increased by increasing K, Na content.5) Using desulfurization slag to produce ceramics, when adding waste stone powder, replacing the sand with molybdenum mine tailings and glazing to ceramic surface can finally reduce the release rate of SO2 to about 25%6) CoMPared with the sample without adding industrial waste, the flexural strength of the glazed product using 30% molybdenum mine tailings, 6% desulphurization slag and 10% waste stone powder as starting materials sintering at 1050℃for 1h increased from 1.7MPa to 10.7MPa, while the water absorption decrease from 6.5% to 5.3% Meanwhile, the rest performances of it can reach the requirements of first-class products of GB/T21149-2007"Sintered Tile".Utilization of molybdenum mine tailings, slag and artificial stone powder to produce sintered tile, not only makes waste to treasure with sustainable meaning, but also could open up a new way to apply industrial wastes.