Ceramic Resource Evaluation?Performance Improvement And Porcelain Research Of Granite Porphyry From Ehu

The depletion of traditional porcelain making materials and the lack of innovative porcelain making technology in Jingdezhen once turned Jingdezhen from the birthplace of porcelain production into a tourist city of ceramic culture.The discovery of Ehu town's granite porphyry is expected to revitalize the porcelain making industry in Jingdezhen.In this paper,the ceramic resources of Ehu town's granite porphyry were firstly evaluated,and then the plasticizing and iron removal of the mineral were studied in view of its poor plasticity and high content of harmful element iron.Further,the trial production of high-temperature daily ceramic body and the preliminary test of porcelain formation were carried out.The main conclusions are as follows:(1)The raw material of Ehu town's granite porphyry is the weathering product of bedrock.Its chemical composition is similar to that of traditional porcelain stone.Its mineral composition is mainly Kaolinite,Muscovite,microplagioclase and Quartz.The content of iron oxide in the ore sample is > 1wt%,which is of poor grade as ceramic raw material.The amount of strong magnetic iron is small.Most of the iron in the colloidal state is weak magnetic iron,which exists in the interlayer structure of Kaolinite or Muscovite.(2)The addition of bentonite,CMC or glycerol can improve the plasticity of the clay from low plasticity to medium plasticity;The addition of PVA can improve the plasticity of clay samples to high plasticity.Considering the price factor,4wt%bentonite or 0.4wt% CMC should be added.Adding a small amount of burnt talc or cobalt-containing leek edge(panting slag)can make the burning whiteness of the formula body slightly increased in the oxidation and reduction flames.(3)Chashan ore sample was bleached by reduction-complexation method.The optimal bleaching conditions were as follows: p H=10,temperature 70?,EDTA dosage 7.5wt%,Thiourea dioxide dosage 2.5wt%,reaction time 20min;Under the optimum technological conditions,the natural whiteness of Chashan ore sample is increased from 62.65% to 72.19%,and the iron removal rate is 22.29%.(4)Magnetic separation was used to remove iron from Chashan ore sample.The optimal iron removal process was as follows: the average particle size of slurry was9.55?m,solid content of slurry was 20%,and removal times were 2 times;Adding dispersant has great influence on iron removal,and the best dispersant is sodium tripolyphosphate.When adding 0.2wt%,iron removal rate can be increased from38.55% to 46.98%.The compound additive----0.2wt% sodium tripolyphosphate+0.2wt% 2-ethylhexaoxy propyl amine had better iron removal effect,and the iron removal rate could reach 62.65% at one time,and the aluminum content was basically the same as that of the single addition of sodium tripolyphosphate.(5)Using Jingdezhen traditional high temperature daily ceramic production process and Chashan iron removal concentrate as raw material,the body formula and glaze formula with good adaptability were obtained.The whiteness of firing was60.21%,and the thermal stability test(180??20?)passed the test,meeting the requirements of the national standard of first-class porcelain for daily use.The specific formula is as follows:Tea mountain concentrate body formula(wt%): Chashan concentrate 65,kaolin35,bentonite 1.Glaze formula(wt%): Kaolinite 7,Barium carbonate 3.5,Zinc oxide 1.7,Burnt talc 3.5,Chashan concentrate 30.4,Quartz 19.1,Potassium feldspar 26.1,Limestone 8.7.