添加剂防控准东高碱煤灰沉积问题的研究进展OA

Research findings related to the use of silicon-aluminum additives and phosphorus-based additives in controlling the ash deposition during the combustion of Zhundong coal are reviewed,providing references for the practical operation of boilers.The Zhundong region in Xinjiang is rich in coal resources,but due to the high content of alkali and alkaline earth metals in Zhundong coal,the resulting ash deposits and slag layers are difficult to remove,affecting the heat transfer on boiler heating surfaces.The most economically viable additive technologies are summarized,with a particular focus on the latest research findings regarding kaolin,vermiculite,and sludge in addressing the ash deposition problem of Zhundong coal.Kaolin,rich in Si-Al,can effectively capture Na and transform into high-melting-point substances such as quartz and mullite at high temperatures.Field boiler tests indicate that adding 6%‒8%kaolin can prevent the formation of obvious slag layers on the heating surfaces,and the boiler operates with favorable parameters,showing promising application prospects.Layered vermiculite can result in loose and porous ash and slag,facilitating the removal.By adding vermiculite,kaolin,and other industrial solid wastes or coal mine by-products in appropriate proportions according to the coal type,the ash accumulation and slagging of Zhundong coal can be effectively reduced.The addition of oil shale and coal gangue at proportions of 15%and 10%,respectively,can alleviate the slagging problem of Zhundong coal;however,if the proportions are too high,severe ash accumulation on boiler heating surfaces and pipelines may occur,increasing the risk of tube rupture.Sludge,which is rich in phosphorus,can serve as a phosphorus-rich additive,and controlling the addition ratio to within 10%is beneficial for increasing the melting point of coal ash,achieving the goal of"utilizing solid waste to control slagging".Phosphorus-based additives mainly include NH4H2PO4 and Ca3(PO4)2,which primarily react with Ca,Na,and Fe in Zhundong coal to form high-melting-point substances,but the feasibility of practical application and economic viability need to be further assessed.