| Stone coal vanadium ore is a sort of unique vanadium-bearing resource in China.The characteristic of stone coal vanadium ore is related to Geological environmental factors and other factors.The stone coal vanadium ores from different areas have different characteristic.In this paper,aiming at the stone coal vanadium ore of Shaanxi Qinfeng Technology Co.,Ltd.,breaking through the traditional static roasting process,carried out research on suspension oxidizing roasting and acid leaching from stone coal vanadium ore.Therefore,it is of great practical significance to carry out relevant technical and basic theoretical.It has important guiding significance for the stone coal vanadium ore for the area and the same type as the stone coal vanadium ore to exploitation and utilization.Firstly,in this paper,the vanadium-containing mica ore from Shanxi was used as the raw material.This paper carried out research on suspension oxidizing roasting and acid leaching from vanadium-bearing mica.The effects of roasting temperature,roasting time,roasting gas flow and roasting O2 concentration on the rate of leaching vanadium were studied.The vanadium-containing mica ore and the roasted products were investigated by relevant modern testing techniques.The results showed that the vanadium-containing mica was concentrated with the roasting temperature at 950℃,the roasting time at 4 h,the O2 concentration at 35%,the total gas volume at 600 mL/min.The vanadium-containing mica ore and the roasted products were leached by leaching temperature 90℃,leaching time 3 h at liquid-solid mass ratio 6:1,and addition of sulfuric acid(mass fraction)20%.Finally,the rate of leaching vanadium can reach 73.34%.The goal of breaking crystal and extracting vanadium from vanadium-containing mica was achieved.it provided guiding significance for vanadium extraction from mica-type vanadium-containing stone coal.Secondly,in this paper,the mica-type vanadium-containing stone coal from Shaanxi Qinfeng Technology Co.,Ltd.was used as the raw material.This paper carried out research on different stages on suspension oxidizing roasting and acid leaching from the stone coal vanadium ore.The results show that the best roasting particle size is-0.074 mm content accounts for 95.59%.The stone coal vanadium was concentrated with the roasting temperature at 650℃,the roasting time at 0.5 h in the first stage.The carbon content of the roasted material can be reduced to 0.034%.The roasted products were leached by leaching temperature 90℃,leaching time 3 h at liquid-solid mass ratio 6:1,and addition of sulfuric acid(mass fraction)20%.The rate of leaching vanadium can reach 46.47%.The stone coal vanadium was concentrated with the roasting temperature at 850 ℃,the roasting time at 3 h,the O2 concentration at 35%,the total gas volume at 600 mL/min in the second stage.The roasted products were leached by leaching temperature 90 ℃,leaching time 3 h at liquid-solid mass ratio 6:1,and addition of sulfuric acid(mass fraction)20%.Above all,the rate of leaching vanadium can reach 68.89%.The results showed that the different first stage of roasting-acid leaching process has achieved the purpose of low-temperature decarburization and high-temperature crystal breaking to extract vanadium from stone coal vanadium ore.The investigations on thermomechanical analysis from the roasting process of stone coal vanadium showed that the oxidation reaction of carbon and pyrite is easier than the oxidation reaction of vanadium.In order to prevent reducing substances such as carbon and pyrite from hindering the conversion of low-priced vanadium to high-priced vanadium,it should be removing the carbon and pyrite from the stone coal vanadium ore at the low temperature(below 873.15 K),and roasting at high temperature.At the same time,chemical analysis,TG-DSCDTG,XRD,FTIR,SEM-EDS,BET and other analytical methods were used to analyze the chemical composition,phase composition analysis,microscopic morphology and structure analysis of the stone coal vanadium ore which were roasted at different stages.The results showed that,the first roasting stage mainly removed carbon and pyrite from stone coal vanadium,and the second roasting stage mainly transformed the low-value vanadium for highvalue vanadium by oxidation reaction.When the temperature at the range of 20 to 1200℃,the weight loss rate of stone coal vanadium was 11.34%.The microstructure analysis results of the products before and after the ore roasting show that the first stage roasting could make the mineral particles of stone coal vanadium become porous,and the second stage roasting can change the morphology and structure of the mineral particles of stone coal vanadium.Therefore,the low-temperature decarburization-high-temperature oxidation staged roasting method for mica-type vanadium-bearing stone coal can achieve the purpose of crystal breaking and vanadium extraction from the ore.In this paper,the technological process of suspension oxidizing roasting on stone coal vanadium ore was carried out,and the phase transformation,the valence transformation microstructure evolution of the samples were verified.It enriched that the theoretical system of suspension oxidation roasting of complex refractory from stone coal vanadium ore and laid the foundation for the efficient use of mica-type stone coal vanadium ore. |
PDF Full Text Request