| Nowadays China is developing at top speed both in society and economy.The coordinated development between industrialization and urbanization is a key path to building a harmony society roundly.Building energy saving and Industrial solid waste resource utilization were two momentous areas which were developing actively in our country.Hydrothermal synthesis reaction has quite strong containment to varied raw materials.Meanwhile,Hydrothermal-synthesis energy-saving porous material?HEPM?is one of the structure function integration wall materials which can achieve self-heat insulation with sole material.Therefore,researching of green manufacturing raw material system and process system of HEPM has the dual significance of environmental protection and energy saving.This article was funded by National Science and Technology Support Project of China?2011BAJ03B03?.Effect and mechanism of siliceous solid waste,calcareous solid waste on HEPM slurry property and physical-mechanical properties was discussed systematically.Based on the influence of slurry performance adjusting components on rough-body forming process and physical-mechanical properties,rough-body forming process adjustment method suitable for high-waste content HEPM system was proposed.Influence mechanism of calcium-silicon solid waste and slurry performance adjustment component on HEPM hydrothermal synthesis of hydration products were investigated by microcosmic measures and tests such as field-emission high resolution transmissionelectron microscopy?FESEM?,energy dispersive X-ray?EDX?,X-ray diffraction?XRD?,differential scanning calorimetry-thermogravimetry?DSC-TG?and nuclear magnetic resonance?NMR?.Based on design of green material system,calcium-silicon solid waste hydrid ball mill technology and microwave gas forming and pre-curing technology were presented innovatively.Through systematically research of green raw material system,rough-body forming process and green manufacturing technology,efficient and stable green manufacturing technology of B04,A2.0 and B05,A2.5 HEPM by utilizing more than85%industrial solid waste which using low-silicon iron tailings and quartz tailings as siliceous material and carbide slag as main calcareous material was achieved.The main research and obtained important achievement of this article as follows:1.HEPM green raw material system and influential mechanism.?1?The increasing proportion of low-silicon iron tailings,which is siliceous solid waste,has significant adverse effects on mechanical property of HEPM.It can meet the requirements ofB05,A2.5 grade in GB 11968-2006 when iron tailing specific surface area reaches 340m2/kg,the ratio in siliceous materials is lower than 60%in single component substitution system,however,the value decreased to 50%in high-waste content HEPM system.?2?As low content of SiO2 in low-silicon iron tailings and most were existed in composite silicate minerals,total content of C-S-H significantly reduced when the low-silicon iron tailings substitution amount increased.When specific surface area of low-silicon iron tailings fluctuation between 250m2/kg to 370m2/kg,the amount of C-S-H has no significant variation.However,reaction of white mica in hydrothermal-synthesis was promoted and tobermorite crystallinity declined when low-silicon iron tailings fineness increased.?3?Rough-body forming process was severely affected by substitution content of carbide slag to quicklime.With increasing of carbide slag substitution content,quick lime hydration exothermic effect weakened gradually,rough-body 0.8 gas rate time prolonged from 9mins to 30mins,final gas rate reduced from 1.5 to 1.2,products bulk density increased and rough-body thickening velocity significantly retarded.Kalklk varied between 0.460.66 and specific surface area of carbide slag fluctuation between 228m2/kg to 325m2/kg has little effect on rough-body forming process.?4?From the angle of mechanical property,quicklime can be totally substituted by carbide slag.Kalk increases between 0.460.66 gradually enhance the compressive strengthof products.Along with the specific surface area of carbide slag increasing from 228m2/kg to 325m2/kg,the compressive strength promoted from 2.5MPa to2.7MPa.?5?The increasing of carbide slag substitution content caused a few reductions of C-S-H?B?and tobermorite.Meanwhile,increasing of Kalk between 0.460.66and carbide slag fineness can improve the formation of C-S-H.2.Rough-body forming process adjustment method and the influence on physical-mechanical property and hydration products.?1?Adjusting water to material ratio?W/R?to 0.540.56,which slurry fluidity between 180mm to 190mm,not only improve slurry stability but also achieve high specific strength of high-waste content HEPM.The reduction of bulk density and compressive strength was attributed to the increasing of capillary pores in pore-wall structure which generated by water evaporation.?2?Due to the quick hydration speed and high hydration heat of sulphate aluminium cement?SAC?,slurry gas forming rate boosted in early stage,thickening accelerated after gas foaming ended and the porous structure rapidly stabilized.Substituting 25%50%PO42.5 by SAC,the compressive strength of HEPM increased from 2.55MPa to 2.93.0MPa.?3?Highly active compound siliceous enhancer?HCSE?can improve slurry foaming in the early stage.The bulk density reduced to 420kg/m3 with 2.152.2MPa in compressive strength,which meet the requirements of grade B04,A2.0 when content of HCSE was 2%.3.Green manufacturing key technologies based on high-waste contentHEPM system.?1?Based on characteristics of high-waste content raw material system,calcium and silicon solid waste mixed wet milling technology which using siliceous material as grinding media of calcareous material was proposed to improve grinding efficiency.The new mix milling method promoted grinding efficient of calcium and siliceous material,improved mix uniformity,furthermore,hydrothermal synthesis reaction rateof calcium and siliceous was promoted and generating of C-S-H was improved with compressive strength increased by 58%.On the other hand,the quicklime crushing,grinding and storage process could be discarded.?2?Based on technological requirements of high-waste content HEPM system rough-body forming process,a new rough-body forming process control technology which was based on microwave heating was proposed.Comparing with the rough-body forming process under the traditional curing condition,final gas rate increased by 37%,gas forming time decreased by 1030%and rough-body thickening rate accelerated by different levels with different microwave curing temperature with this new pre-curing process.?3?The application of high-waste content HEPM system to industry indicated that rough-body forming process is stable and efficient,Physical-mechanical property meet the requirements of grade B05,A2.5,thermal conductivity is 0.1250.131W/?m·K?and over 95%products were qualified during the process. |
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