Research On Preparation And Thermal Mechanism Of The Exothermic Insulating Riser Based On Organosilicon Residue

In recent years,as China’s silicone production capacity continues to expand,the production and use of silicone products are also increasing,resulting in a large number of silicone waste slurry generation.Usually,after the slurry has been treated by hydrolysis,most of the silane peroxide is recovered,but most of the residual solid waste silicone residue is disposed of in landfills.The main component of organosilicon residue is monomeric silicon,and at the same time contains a small number of impurities such as metals,organic substances,etc.If not handled properly,it will not only cause environmental resource pollution but also threaten people’s health and safety.To establish the concept of sustainable development and adhere to green manufacturing,there is an urgent need to explore a resource utilization method for organosilicon residue.In this paper,the waste silicone residue from the production of silicone material company as raw material was selected,and after harmless treatment,a new type of heat-insulating casing with silicone residue left as the basic heating agent was developed,which can solve the problem of resource utilization of silicone residue,and at the same time apply it to the casting field to reduce the production cost of the heat-insulating casing.First,the study of the physical and chemical properties of the organosilicon residue after harmless treatment,through scanning electron microscope（SEM）,X-ray diffraction system（XRD）,and other characterization means,as well as calorific value,ignition point,and thermal stability of the test method,to determine the feasibility of organosilicon residue as a heating agent.The results show that:the treated silica residue was dominated by monomeric Si,with surface impurities lower than 1%,and the silica residue particles were porous junction,which could effectively reduce heat conduction;the calorific value of silica residue combustion was slightly lower than that of general pure silica powder,and the ignition point was 173.1℃,and the thermal stability was good at 120℃.Then,by studying the heating mechanism of the heating insulation riser,the influencing factors affecting the heating performance of the riser were analyzed,and the main composition ratio parameters of the riser were determined through single-factor experiments.The results show that:the best effect was achieved when the heating agent was mixed with21%organosilicon residue and 14%aluminum powder.The best use parameters of single oxidizer were Fe₃O₄ at 8-12%,Mn O₂ at 4-8%,and KNO₃ at 4-6%;flux Na₃Al F₆ had a better combustion effect than K₃Al F₆,with the additional amount of 4%;binder alkali phenolic resin was added at 12%.When the particle size base is composed of 75-150μm organic silicon slag and 75μm fine hollow floating beads,the compressive strength was above 4Mpa and the air permeability is above 70mm/s.Finally,the optimized formulations were analyzed by the orthogonal optimization method for the heating agent and oxidizing agent,and the optimized results were used to make the riser sets for actual combustion and casting tests.The results show that the optimal ratio of heating agent and oxidizing agent was 21%of organosilicon residue,14%of aluminum powder,12%of Fe₃O₄,6%of Mn O₂,and 4%of KNO₃.The holding time for burning the homemade riser set was 14%more than that of the aluminum powder riser set.Casting found that the internal profile of the casting is not defective,and the hardness is around 200 HB.