Experimental Study On Preparation Of Foamed Ceramics From Iron-enriched Coal Gangue

Coal gangue is a kind of solid waste discharged in the process of coal mining.With the increasing demand for energy in China,the storage of coal gangue is increasing year by year.A large number of coal gangue has brought great damage to the surrounding environment.At present,the comprehensive utilization of coal gangue is mainly reflected in three aspects:power generation,production of building materials,land reclamation and backfilling.Coal gangue contains a certain amount of calorific value,so it has the advantage of saving energy in the production of building materials.At present,the types of coal gangue used in the production of building materials are mostly concentrated in high alumina and silica.In the sintering process of preparing building materials,the production of liquid glass phase of Iron-enriched gangue is low at low temperature and impurity bubbles appear during sintering,therefore,there are few studies related to it.Based on this,this paper takes the Iron-enriched coal gangue accumulated in Dongshechang of Fushun City,Liaoning Province as the breakthrough point,relying on the "union research center on solid waste resource utilization" unite established by Fushun Hanwang green building materials Co.,Ltd.and Northeast University.Through theoretical and experimental research,the foamed ceramics with 75%gangue content,light weight,high strength and good thermal insulation performance were prepared by adding pore forming agent,the specific work is as follows:(1)Based on the experimental results and related theories,the foaming mechanism of Iron-enriched coal gangue foamed ceramics was studied.This paper explores the problems of sintering foamed ceramics with Iron-enriched coal gangue,and puts forward practical solutions to these problems.(2)The formulation design of foamed ceramics prepared with Iron-enriched coal gangue as the main raw material was studied.Firstly,through single-factor variable experiments,separately analyze the law of action and influence mode of each raw material on the performance of foamed ceramics,and determine the appropriate dosage range of each raw material at the same time.Afterwards,by designing a total of 18 sets of orthogonal experiments with five factors and three levels,using the compressive strength,bulk density and thermal conductivity of the foamed ceramics as the evaluation indicators to explore the relationship between each factor and the performance of the foamed ceramics to accurately obtain the best formula.(3)The relationship between firing parameters and foamed ceramic properties was studied.Based on the thermodynamic analysis of the foamed ceramic formula preformed body during the heating process,four parameters that affect the performance of the foamed ceramic are determined:preheating temperature,preheating time,sintering temperature,and sintering time.A single factor variable experiment was performed on the four major parameters to determine the appropriate range of each factor.On the basis of the single factor experiment of the four major factors,each factor was selected at four levels to design the L16(44)orthogonal experiment.Density,compressive strength and thermal conductivity are the indicators,and through variance and range analysis,the relationship between the influence size and significance of each factor and the performance of the foamed ceramic sample is explored,and the best firing parameters are determined.(4)By referring to the relevant economic data,combined with the formula and sintering parameters of foamed ceramics,the industrialization planning of Iron-enriched coal gangue foamed ceramics was carried out.This paper takes Iron-enriched coal gangue as the research object,explores the method of preparing foamed ceramics using Iron-enriched coal gangue as the main raw material,realizes the high value-added utilization of Iron-enriched coal gangue,and reduces the environmental pressure of coal gangue dump,can make a certain contribution to local environmental protection.