Exprimental Research On Kyanite Ore From Gansu

Kyanite plays a very important role in industrial production.It is widely used and its usage is very large.With the reserves of high-grade and less-impurities Kyanite ore is less and less,researching on separating Kyanite from low-quality Kynaite ore is more and more important.This paper includes the process mineralogy of the Kynite ore from Gansu province,the grinding test,acid and alkaline flotation test.At last,throuth the dry magnetic concentration-gravity concentration-flotation-strong magnetic separation process,we get the viable Kyanite concentrate product.The main chemical composition of the Kynatie ore is Al₂O₃19.37%,SiO₂63.76%.It also contains a lot of Fe₂O₃.The content of Fe₂O₃ even reach up to 7.37%.It mainly exists in Biotite and Garnet.The dissemination size of Kyanite is large,but the symbiotic relationship between Kyanite and gangue minerals are very complicated.So,the key and difficult points of the subject are to separate Kyanite from gangue minerals and to reduce the content of Fe₂O₃.The grinding test tells us that rod mill is fit for this Kyanite ore.The grinding fineness is the size of the ore bellow 0.074mm account for 70.09%.High gradient magnetic separation has a good effect on iron removal.The efficiency of iron-removal is 79.05%.So,high gradient magnetic separation can be used to remove the iron in Kyanite concentrate.The optimal experimental condition of high gradient magnetic separation is magnetic field intensity 1.0T,pulsation frequency 800r/min.There is a mass of mica in raw ore.Reverse floating before floating Kyanite can remove some mica,but it can give rise to the loss of some Kynite,which lead to the recovery of Kyanite is very low.The dosage of lauryl amine in reverse flotation is 120g/t.The sodium oleate is used as collector in alkaline flotation test.Throuth one time reverse flotation,two times scavenging,one time roughing,three times concentration,one time high gradient magnetic separation,we get the Kyanite concentrate.It's grade of Al₂O₃ is 48.00%,it's recovery is 16.04%.It is difficult to get the Kyanite concentrate with high grade and high recovery by alkaline flotation.Petroleum sulfonate is used as collector in acid flotation test.Throuth one time reverse flotation,one time roughing,three times concentration,one time high gradient magnetic separation,we get the Kyanite concentrate.It's grade of Al₂O₃ is 54.75%,it's recovery is 15.25%.The grade of the concentrate is approach but still not reach the standard of LJ-55,and it's recovery is very low.The dry magnetic concentration and spiral test can remove some gangue ores before flotation.We take the raw with size of-2mm four times dry magnetic concentration,griding the nonmagnetic roduct to-0.15mm account for 50%,and then take the spiral test.This process is good for reducing the gangue ores and iron in the pulp.The flotation is in acid medium.After dry magnetic concentration-spiral test-flotation-strongmagnetic separation,we get the qualified Kyanite concentrate.It's Al₂O₃ grade is 58.74%,recovery is 20.97%.It's Kyanite grade is 95.26%,recovery is 75.53%.It reaches the standard of LJ-55.The mechanism study tells us that it is easy forpetroleum sulfonate to separate pure from pure quartz in acid medium?pH=3⁴?,but in real ores flotation,Fe³⁺and Al³⁺can activate quartz,which can reduce selectivity of petroleum sulfonate,and citric acid can be used to depress the quartz activated by Fe³⁺and Al³⁺.Petroleum sulfonate adsorbs on the surface of Kyanite is mainly throuth physical absorption.