System and method for purifying vanadium pentoxide

Patent metadata

Field	Value
Publication number	US-10294118-B2
Application number	US-201615547079-A
Country	US
Kind code	B2
Filing date	Jan 28, 2016
Priority date	Jan 30, 2015
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

The present invention provides a system and method for purifying vanadium pentoxide. 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 purified by rectification, and then subjected to plasma oxidation, thereby obtaining a high-purity vanadium pentoxide product and chlorine gas. The chlorine gas is returned for low temperature chlorination. The system and method have advantages of favorable adaptability to raw material, no discharge of contaminated wastewater, low energy consumption and chlorine consumption in production, stable product quality, etc.

First claim

What is claimed is:

1. A system for purifying vanadium pentoxide, comprising a feeding device, a low temperature chlorination fluidized bed, a rectification and purification device, a plasma oxidation device, 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 plasma oxidation device comprises an air filtration purifier, a reactant nozzle, a plasma reactor, a primary cyclone separator, a secondary cyclone separator, a rotary-vane pump and a gas compressor;
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 reflux 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;
a gas inlet of the air filtration purifier is connected with the compressed air main pipe through a pipeline; a gas outlet of the air filtration purifier is connected with an air inlet of the reactant nozzle and a gas inlet of the secondary cyclone separator through pipelines, respectively; a liquid outlet of the high-purity vanadium oxytrichloride storage tank is connected with a chloride inlet of the reactant nozzle through a pipeline; the reactant nozzle is provided at the center of the upper part of the plasma reactor; a feed outlet at the bottom of the plasma reactor is connected with a gas inlet of the primary cyclone separator through a pipeline; a gas outlet of the primary cyclone separator is connected with a gas inlet of the rotary-vane pump through a pipeline; a gas outlet of the rotary-vane pump is connected with a gas inlet of the gas compressor through a pipeline; a gas outlet of the gas compressor is connected with a cold gas inlet of the flue gas heat exchanger through a pipeline; a feed discharge opening at the lower part of the primary cyclone separator is connected with a gas inlet of the secondary cyclone separator through a pipeline; a gas outlet at the top of the secondary cyclone separator is connected with a gas inlet of the tail gas washing absorber through a pipeline; and a feed outlet at the bottom of the secondary cyclone separator is connected with a high-purity vanadium pentoxide product hopper 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.

2. A method for purifying vanadium pentoxide based on the system of claim 1 , comprising the following steps:
allowing industrial grade vanadium pentoxide powder in the industrial grade vanadium pentoxide hopper and carbon powder in the carbon powder hopper to enter the chlorination bed feeder simultaneously through the industrial grade vanadium pentoxide screw feeder and the carbon powder screw feeder respectively and be mixed therein, and then enter the chlorination fluidized bed body; allowing chlorine gas from the chlorine gas source main pipe, nitrogen gas from the nitrogen gas source main pipe, air from the compressed air main pipe and chlorine-containing gas returned from the gas compressor to be preheated by exchanging heat with chlorination flue gas by the flue gas heat exchanger, and then enter the chlorination fluidized bed body to allow the vanadium pentoxide and the carbon powder to be kept at a fluidized state and chemically reacted, wherein the air enables a part of the carbon powder to combust to provide heat for maintaining the temperature of the fluid bed, and the chlorine gas and the carbon powder function together to make vanadium pentoxide and a s

Assignees

• Inst Process Eng Cas
• Beijing Zhongkaihongde Tech Co Ltd

Inventors

• Zhu Qingshan
• Fan Chuanlin
• Mu Wenheng
• Liu Jibin
• Wang Cunhu
• Ban Qixun

Classifications

• B01D3/14

  Fractional distillation {or use of a fractionation or rectification column} · CPC title

• C01P2006/80

  Compositional purity · CPC title

• C01G31/02 Primary

  Oxides · CPC title

• C01G31/04

  Halides · CPC title

• B01D19/0057

  the centrifugal movement being caused by a vortex, e.g. using a cyclone, or by a tangential inlet · CPC title