Study On Foam Insulation Ceramics Of Coal Mine Solid Reject

Foam insulation ceramic is a new kind of green energy-efficiency buildingmaterial, which owns uniform distribution of a large number of closed pores. It hashigh apparent density and high porosity, and because of the characteristics of lightweight, heat insulation, thermal insulation, fire prevention, non-combustibility and soon, it is especially suitable for building exterior wall, roof insulation off-grade systemand fire isolation, etc.Coal gangue and shale are solid wastes resulting from the process of coal miningand washing, quartz and kaolinite are the main mineral composition of them. They aregenerally disposed by piled or landfilled; it’s not only invaded land, causedenvironment pollution, but also brought great security risks. Furthermore, it’s a wasteof resources. In this paper, coal mining waste coal gangue and shale were used asmain materials, polishing slag as the main pore-forming agent and talc as flux. Theapparent density, porosity rate and water absorption were influenced by the combinedfunction of different composition of raw materials and preparation process.Design a3factors and3levels orthogonal test to investigate the effect of thesintering temperature, talc content and polishing slag content on foam insulatingceramics. The results show that sintering temperature was the main influence whilethe content of talc and polishing slag were fixed. When sintering temperature at1250°C, talc and polishing slag content were10%and25%respectively, the productshad better performance. The specimens were light with closed pores of uniformdistribution, and apparent density were0.80~0.90g/cm3, porosity were over50%andwater absorption were less than2%.Analyzed the materials’ composition and structure, it would be found that themain crystal phase of foam insulation ceramics at1250°C were cordierite(2MgO·2Al2O3·5SiO2) and quartz (SiO2), which have uniform distribution of closedpores, and the pore size were less than1mm. While specimens’ grain growth weremore perfect at1270°C, and the main crystal phase was cordierite. Materials’ porositywere higher and aperture is bigger.On this basis, controllable preparation was studied for the materials. The resultsshow that sintering temperature should be chosen at1230~1250°C;heating rate wouldbe appropriate of around10°C/min; By stage type of warming way, and the holdingtime was controlled in10min can get closed pores materials with same size inprinciple of apertures. Based on the study of ternary phase diagram，using Surfer8.0to draw contour maps, the results show that under the conditions of coal gangue toshale ratio was kept at4:1and65~70%total content,10~15%talc content,20~25%polishing slag content, the apparent density of foam insulating ceramics were lessthan1g/cm3, porosity were greater than50%and bibulous rate were less than1%.