Synthesis And Hydration Research Of Ternersite

Ternesite is one of the mineral phases appearing in the calcination process of sulfoaluminate cement clinker.The formation and stabilization temperature of ternisite is between 1000℃ and 1200℃,which is about 100℃ lower than the calcination temperature of sulfoaluminate cement,and the energy consumption can be reduced in production.Compared with Belite,ternesite has a lower calcium-silicon ratio and consumes less limestone during the production process,thus reducing carbon emissions.Actually,ternesite has potential hydration activity.This paper mainly explores the preparation and hydration of ternesite with different raw materials,so as to find out the application range of ternesite minerals.Firstly,this paper explores the produce method of ternesite mineral influence factors.Starting from raw materials,the synthesis of ternesite mineral was investigated by using analytical pure reagents and common raw materials.The results show that the synthesis of ternesite mineral with pure analytical reagent as raw material requires the addition of mineralizers.The better mineralizers are calcium fluoride,sodium sulfate and calcium phosphate.Calcium fluoride and sodium sulfate can obtain the most ternesite mineral when the active component is 0.2%.The addition of calcium phosphate can make the ternesite exist in large quantities at higher temperature,make the ternesite exist more stably,and also have an effect on the morphology of the prepared ternesite.In addition,ternesite mineral and sulpho-aluminate cement containing ternesite mineral can also be prepared in large quantities by using common raw materials such as limestone,gypsum,kaolin and silica fume.Secondly,the hydration of ternesite mineral is studied deeply.The experiment proves that ternesite mineral has good long-term hydration performance.The strength of curing at room temperature for 450 days reaches 28 MPa,and the hydration p H stabilizes at about12.The hydration products are mainly dihydrate gypsum,hemihydrate gypsum,and calcium carbonate.The hydration activity of ternesite can be improved by increasing curing temperature,and the strength of 91 d is 3 times that of normal temperature.At the same time,the influence of the ions doped during the preparation process and doped during hydration were also investigated.The results show that sodium ions can increase the activity of ternesite and hydration p H,both internal and external.However,fluoride ion has little effect on the hydration of ternesite.The addition of aluminum ions has little effect on hydration,but the addition of calcium sulfoaluminate can promote the hydration degree of calcium sulfosilicate.Finally,the hydration of ternesite mineral prepared from common raw materials limestone,gypsum,silica silica and kaolin was explored,and the hydration of sulphoaluminate cement clinker with high content of ternesite prepared from common raw materials was also explored.The test results on the basic hydration properties and hydration degree show that the high ternesite minerals prepared from common raw materials have the same long-term hydration properties.The hydration performance of ternisite-sulfoaluminate cement is related to the content of ternesite,and increasing the content of ternesite is beneficial to the development of late strength and improve the carbonization resistance.