US 10,053,371 B2 · System and method for preparing high-purity vanadium pentoxide powder

Abstract

The present invention provides a system and method for preparing high-purity vanadium pentoxide powder. Industrial grade vanadium pentoxide is converted to vanadium oxytrichloride by low temperature fluidizing chlorination, wherein chlorinating gas is preheated via heat exchange between fluidizing gas and chlorination flue gas, and an appropriate amount of air is added to enable a part of carbon powder to combust so as to achieve a balanced heat supply during the chlorination, thereby increasing the efficiency of chlorination and ensuring good selectivity in low temperature chlorination. The vanadium oxytrichloride is subjected to purification by rectification, ammonium salt precipitation and fluidized calcination, thereby obtaining high-purity vanadium pentoxide, wherein the ammonia gas produced during calcination is condensed and then recycled for ammonium salt precipitation. The system and method have advantages of favorable adaptability to raw material, less pollution, low energy consumption in production, low operation cost, stable product quality, etc.

A system for preparing high-purity vanadium pentoxide powder, comprising a feeding device, a low temperature chlorination fluidized bed, a rectification and purification device, an ammonium salt precipitation device, an ammonium salt feeding device, a calcination fluidized bed, a tail gas washing absorber, an induced draft fan and a chimney;

wherein the feeding device comprises an industrial grade vanadium pentoxide hopper, an industrial grade vanadium pentoxide screw feeder, a carbon powder hopper and a carbon powder screw feeder;
the low temperature chlorination fluidized bed comprises a chlorination bed feeder, a chlorination fluidized bed body, a chlorination bed cyclone separator, a flue gas heat exchanger, a flue gas condenser, a chlorination bed acid-seal tank and a chlorination bed spiral slag-discharging device;
the rectification and purification device comprises a distilling still, a rectifying column, a distillate condenser, a reflux liquid collecting tank, a silicon-containing vanadium oxytrichloride storage tank, a rectification section acid-seal tank, a high-purity vanadium oxytrichloride condenser, and a high-purity vanadium oxytrichloride storage tank;
the ammonium salt precipitation device comprises an ammonium salt precipitation reaction tank and a washing filter;
the ammonium salt feeding device comprises an ammonium salt hopper and an ammonium salt screw feeder;
the calcination fluidized bed comprises an air purifier, a gas heater, a calcination bed feeder, a calcination fluidized bed body, a calcination bed cyclone separator and an ammonia gas condenser;
wherein a feed outlet at the bottom of the industrial grade vanadium pentoxide hopper is connected with a feed inlet of the industrial grade vanadium pentoxide screw feeder;
a feed outlet at the bottom of the carbon powder hopper is connected with a feed inlet of the carbon powder screw feeder;
and a feed outlet of the industrial grade vanadium pentoxide screw feeder and a feed outlet of the carbon powder screw feeder are both connected with a feed inlet of the chlorination bed feeder through a pipeline;
a feed discharge opening of the chlorination bed feeder is connected with a feed inlet at the upper part of the chlorination fluidized bed body through a pipeline;
a gas inlet at the bottom of the chlorination bed feeder is connected with a nitrogen gas source main pipe through a pipeline;
the chlorination bed cyclone separator is provided at the center of the top of the expansion section of the chlorination fluidized bed body;
a gas outlet at the top of the chlorination bed cyclone separator is connected with a hot flue gas inlet of the flue gas heat exchanger through a pipeline;
a cold flue gas outlet of the flue gas heat exchanger is connected with a gas inlet of the flue gas condenser through a pipeline;
a gas outlet of the flue gas condenser is connected with a gas inlet of the chlorination bed acid-seal tank through a pipeline;
a gas outlet of the chlorination bed acid-seal tank is connected with a gas inlet of the tail gas washing absorber through a pipeline;
a slag-discharge opening at the lower part of the chlorination fluidized bed body is connected with a feed inlet of the chlorination bed spiral slag-discharging device through a pipeline;
a gas inlet at the bottom of the chlorination fluidized bed body is connected with a hot gas outlet of the flue gas heat exchanger through a pipeline;
and a cold gas inlet of the flue gas heat exchanger is connected with a chlorine gas source main pipe, the nitrogen gas source main pipe and a compressed air main pipe through pipelines, respectively;
a liquid outlet at the bottom of the flue gas condenser is connected with a feed inlet of the rectifying column through a pipeline;
a steam outlet of the distilling still is connected with a steam inlet of the rectifying column through a pipeline;
a backflow inlet of the distilling still is connected with a liquid reflux outlet at the bottom of the rectifying column through a pipeline;
a gas outlet at the top of the rectifying column is connected with a gas inlet of the distillate condenser through a pipeline;
a liquid outlet of the distillate condenser is connected with a liquid inlet of the reflux liquid collecting tank through a pipeline;
a reflux liquid outlet of the reflux liquid collecting tank is connected with a reflux liquid inlet at the top of the rectifying column through a pipeline;
a feed discharge opening of the reflux liquid collecting tank is connected with an inlet of the silicon-containing vanadium oxytrichloride storage tank through a pipeline;
an exhaust gas outlet of the silicon-containing vanadium oxytrichloride storage tank is connected with a gas inlet of the rectification section acid-seal tank through a pipeline;
a gas outlet of the rectification section acid-seal tank is connected with a gas inlet of the tail gas washing absorber through a pipeline;
a rectificate outlet of the rectifying column is connected with a gas inlet of the high-purity vanadium oxytrichloride condenser through a pipeline;
a liquid outlet of the high-purity vanadium oxytrichloride condenser is connected with a liquid inlet of the high-purity vanadium oxytrichloride storage tank through a pipeline;
and an underflow outlet is provided at the bottom of the distilling still;
an ammonia solution inlet of the ammonium salt precipitation reaction tank is connected with a purified aqueous ammonia main pipe and an aqueous ammonia outlet at the bottom of the ammonia gas condenser through pipelines, respectively;
a chloride inlet of the ammonium salt precipitation reaction tank is connected with a liquid outlet of the high-purity vanadium oxytrichloride storage tank through a pipeline;
a slurry outlet of the ammonium salt precipitation reaction tank is connected with a slurry inlet of the washing filter through a pipeline;
a clear water inlet of the washing filter is connected with an ultrapure water main pipe through a pipeline;
a washing liquid outlet of the washing filter is connected with a wastewater treatment unit through a pipeline;
and a solid material outlet of the washing filter is connected with a feed inlet of the ammonium salt hopper through a pipeline;
a feed outlet at the bottom of the ammonium salt hopper is connected with a feed inlet of the ammonium salt screw feeder;
and a feed outlet of the ammonium salt screw feeder is connected with a feed inlet of the calcination bed feeder through a pipeline;
a gas inlet of the air purifier is connected with the compressed air main pipe through a pipeline;
a gas outlet of the air purifier is connected with a gas inlet of the gas heater and a gas inlet at the bottom of the calcination bed feeder through pipelines, respectively;
a combustion-supporting wind inlet of a combustion nozzle and a fuel inlet of the gas heater are respectively connected with the compressed air main pipe and a fuel main pipe through pipelines;
a gas outlet of the gas heater is connected with a gas inlet at the bottom of the calcination fluidized bed body through a pipeline;
a feed discharge opening of the calcination bed feeder is connected with a feed inlet at the lower part of the calcination fluidized bed body through a pipeline;
a feed outlet at the upper part of the calcination fluidized bed body is connected with a high-purity vanadium pentoxide product hopper through a pipeline;
the calcination bed cyclone separator is provided at the center of the top of the expansion section of the calcination fluidized bed body;
a gas outlet of the calcination bed cyclone separator is connected with a gas inlet of the ammonia gas condenser through a pipeline;
and a gas outlet of the ammonia gas condenser is connected with a gas inlet of the tail gas washing absorber through a pipeline;
a gas outlet of the tail gas washing absorber is connected with a gas inlet of the induced draft fan through a pipeline;
and a gas outlet of the induced draft fan is connected with a gas inlet at the bottom of the chimney through a pipeline.

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System and method for preparing high-purity vanadium pentoxide powder

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System and method for preparing high-purity vanadium pentoxide powder

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Abstract

Claims8