CN105618162A - Recycling and reusing method of waste vanadium tungsten titanium-based denitration catalyst - Google Patents

Abstract

The invention relates to a recycling and reusing method of a waste vanadium tungsten titanium-based denitration catalyst. The method comprises: cleaning the waste vanadium tungsten titanium-based denitration catalyst by adopting first cleaning fluid and second cleaning fluid, drying and roasting. Optionally, the method further comprises: grinding the roasted recycled materials to prepare the 500-2000 mesh catalyst recycled materials and preparing the catalyst recycled materials into the waste vanadium tungsten titanium-based denitration catalyst. The waste catalyst is cleaned at two steps to remove total harmful toxic components of the waste catalyst. The method uses two kinds of cleaning fluid to ensure that the recycled materials are directly used for preparing the catalyst. The method can realize secondary use of the waste smoke denitration catalyst, realizes recycle of resource, reduces cost, saves energy, reduces environment protection control difficulty and is high in comprehensive benefits.

Description

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst

Technical field

The invention belongs to filed of flue gas purification and in particular it relates to a kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst.

Background technology

Selective catalytic reduction (SelectiveCatalyticReduction is called for short " SCR ") is the method controlling discharged nitrous oxides that coal-burning power plant of China is most widely used, and wherein SCR method core the most is catalyst. Commercial SCR denitration the most frequently used at present is V₂O₅-WO₃/TiO₂System's (out of stock catalyst of vanadium tungsten titanio), V₂O₅-WO₃/TiO₂Series catalysts, in actual application, due to reasons such as catalyst poisoning, duct blocking, abrasions, causes catalyst activity reduction and structural deterioration to go out of use, and the life-span of this catalyst is generally 2��4 years. According to statistics, domestic selective catalytic reduction reaction denitration catalyst requirement is about 300,000 m³/ a. Thus, a large amount of discarded catalyst can be produced after 2��4 years.

Chinese Ministry of Environmental Protection clearly proposes in " notice about strengthening waste flue gas denitration catalyst supervision " of issue in 2014, includes waste flue gas denitration catalyst in danger wastes and is managed, it is desirable to improves its regeneration and utilizes disposing capacity. Therefore, the discarded catalyst for denitrating flue gas of Appropriate application has become current urgent problem.

If at present the recoverying and utilizing method of discarded catalyst for denitrating flue gas being extracted metal-oxide therein by a series of physico-chemical process. Such as, Chinese patent application CN101921916A, title is " from waste flue gas denitration catalyst the method for Footwall drift oxide ", discarded catalyst for denitrating flue gas is damaged, high-temperature roasting is carried out with sodium carbonate after mixing, agglomerate filters after soaking dissolving in the hot water, and precipitate roasting after sulfuric acid treatment obtains titanium dioxide. Filtrate prepares vanadium oxide, tungsten oxide respectively through reconciling pH value. The product purity that the method prepares is relatively low, is difficult to directly apply to catalyst preparing.

Again such as, Chinese patent application CN103343236A, title is " from waste denitration catalyst the method for recovery Pd, vanadium, tungsten ", catalyst is ground, add highly basic and carry out fused salt reaction, add the solution separating of the deionized water solid by titaniferous and tungstenic, vanadium after cooling, tungstenic, vanadium solution through boiling the solution separating by the solid containing vanadium and tungstenic. End product is sodium titanate, sodium metavanadate and sodium tungstate. Product also cannot directly apply to Catalyst Production.

Therefore, develop the recovery method of a kind of vanadium tungsten titanio denitrating catalyst that reclaimed materials can be directly applied to Catalyst Production, meet the growth requirement that current catalyst reclaims.

Summary of the invention

Therefore, it is an object of the invention to provide a kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, the method can be recycled discarded vanadium tungsten titanio denitrating catalyst, the reclaimed materials prepared may be directly applied to prepare denitrating catalyst, the closed loop realizing catalyst utilizes, reduce cost, economize on resources, be more beneficial for avoiding because waste catalyst irrational utilization causes environmental pollution.

It is an object of the invention to be achieved through the following technical solutions.

On the one hand, the invention provides a kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, said method comprising the steps of:

(1) cleaning of discarded vanadium tungsten titanio denitrating catalyst: adopt the first cleanout fluid and the second cleanout fluid that discarded vanadium tungsten titanio denitrating catalyst is carried out successively, until iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, wherein, described first cleanout fluid comprises the water of the sodium hydroxide of 0.01��5wt% and/or potassium hydroxide, the sodium carbonate of 0.01��5wt%, the sodium ethylene diamine tetracetate of 0.001��2wt%, the diethylene-triamine pentaacetic acid sodium of 0.001��2wt%, the sodium nitrilo triacetate of 0��2wt%, the sodium citrate of 0.001��1wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt%, the sodium pyrophosphate of 0.001��1wt% and surplus; With the water that described second cleanout fluid comprises the sulphuric acid of 0.01��15wt%, the citric acid of 0.01��2wt%, the oxalic acid of 0��2wt%, the tartaric acid of 0��2wt%, the ethylenediaminetetraacetic acid of 0.001��1wt%, the nitrilotriacetic acid of 0��0.5wt%, the diethylene-triamine pentaacetic acid of 0��2wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt% and surplus;

(2) dry: the catalyst that step (1) is obtained is dried; With

(3) roasting: catalyst roasting at 300��600 DEG C that step (2) is obtained, it is thus achieved that reclaimed materials.

On the other hand, the invention provides the recovery of a kind of discarded vanadium tungsten titanio denitrating catalyst the method being prepared into catalyst, said method comprising the steps of:

(1) cleaning of discarded vanadium tungsten titanio denitrating catalyst: adopt the first cleanout fluid and the second cleanout fluid that discarded vanadium tungsten titanio denitrating catalyst is carried out successively, until iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, wherein, described first cleanout fluid comprises the water of the sodium hydroxide of 0.01��5wt% and/or potassium hydroxide, the sodium carbonate of 0.01��5wt%, the sodium ethylene diamine tetracetate of 0.001��2wt%, the diethylene-triamine pentaacetic acid sodium of 0.001��2wt%, the sodium nitrilo triacetate of 0��2wt%, the sodium citrate of 0.001��1wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt%, the sodium pyrophosphate of 0.001��1wt% and surplus; With the water that described second cleanout fluid comprises the sulphuric acid of 0.01��15wt%, the citric acid of 0.01��2wt%, the oxalic acid of 0��2wt%, the tartaric acid of 0��2wt%, the ethylenediaminetetraacetic acid of 0.001��1wt%, the nitrilotriacetic acid of 0��0.5wt%, the diethylene-triamine pentaacetic acid of 0��2wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt% and surplus;

(2) dry: the catalyst that step (1) is obtained is dried; With

(3) roasting: catalyst roasting at 300��600 DEG C that step (2) is obtained, it is thus achieved that reclaimed materials;

(4) pulverizing: pulverized by the reclaimed materials after roasting in step (3), the catalyst preparing 500��2000 orders reclaims powder;

(5) catalyst is prepared: the catalyst obtained in step (4) is reclaimed powder and makes vanadium tungsten titanio denitrating catalyst.

According to method provided by the invention, in order to remove the dust in catalyst surface and duct, described method also includes: before cleaning step, first discarded vanadium tungsten titanio denitrating catalyst is carried out dedusting of negative pressure, preferably, described dedusting of negative pressure is to carry out under the vacuum of 20��45kPa.

According to method provided by the invention, wherein, in the first cleanout fluid described in described step (1), the content of sodium nitrilo triacetate is 0.001��2wt%; The content of described second cleanout fluid mesoxalic acid is 0.01��2wt%, and the content of nitrilotriacetic acid is 0.001��0.5wt%'s and diethylene-triamine pentaacetic acid content is 0.001��2wt%.

In some embodiments, described first cleanout fluid comprises the water of the sodium hydroxide of 0.5��5wt% and/or potassium hydroxide, the sodium carbonate of 0.1��5wt%, the sodium ethylene diamine tetracetate of 0.01��1wt%, the diethylene-triamine pentaacetic acid sodium of 0.05��1wt%, the sodium nitrilo triacetate of 0.001��0.1wt%, the sodium citrate of 0.01��1wt%, the JFC of 0.01��1wt%, the OP-10 of 0.01��1wt%, the peregal of 0.01��1wt%, the sodium pyrophosphate of 0.05��1wt% and surplus; And in some preferred embodiments, described first cleanout fluid comprises the sodium hydroxide of 1��3wt% and/or the sodium carbonate of potassium hydroxide and 0.5��3wt%.

In some embodiments, described second cleanout fluid comprise the sulphuric acid of 0.5��15wt%, the citric acid of 0.01��2wt%, the oxalic acid of 0.01��1wt%, 0��2% tartaric acid, the ethylenediaminetetraacetic acid of 0.01��1wt%, the nitrilotriacetic acid of 0.01��0.5wt%, the diethylene-triamine pentaacetic acid of 0��1wt%, the JFC of 0.01��1wt%, the OP-10 of 0.005��1wt%, the peregal of 0.01��1wt% and surplus water; And in some preferred embodiments, described second cleanout fluid comprises the oxalic acid of the sulphuric acid of 0.5��5wt%, the citric acid of 0.1��1wt% and 0.1��0.8wt%.

According to method provided by the invention, wherein, described in described step (1), the consumption of the first cleanout fluid and described second cleanout fluid is each independently the every 0.001m of 1.2��5L cleanout fluid³Catalyst, it is preferred to the every 0.001m of 1.5��4L cleanout fluid³Catalyst.

According to method provided by the invention, wherein, cleaning operation in described step (1) includes: first discarded vanadium tungsten titanio denitrating catalyst is soaked in the first cleanout fluid such as 60��120min, ultrasonic waves for cleaning is or/and pressure pulse cleaning such as 15��480min, preferably 30��240min, more preferably 60��120min; But discarded vanadium tungsten titanio denitrating catalyst is soaked such as 60��120min in the second cleanout fluid, ultrasonic waves for cleaning is or/and pressure pulse cleaning such as 15��480min, it is preferable that 30��240min, more preferably 60��120min.

According to method provided by the invention, described method also includes: after adopting the first cleanout fluid and the second cleanout fluid that discarded vanadium tungsten titanio denitrating catalyst is carried out, catalyst is carried out deionized water cleaning.

According to method provided by the invention, wherein, adopting the temperature that discarded vanadium tungsten titanio denitrating catalyst is carried out by the first cleanout fluid and the second cleanout fluid in described step (1) is 10��90 DEG C, it is preferred to 20��60 DEG C, more preferably 30��60 DEG C.

According to method provided by the invention, wherein, dry in described step (2) temperature is 60��200 DEG C, it is preferred to 80��120 DEG C, the time is 1��48h, it is preferred to 2��30h.

According to method provided by the invention, wherein, in described step (3), the temperature of roasting is 300��500 DEG C, it is preferred to 350��500 DEG C.

According to method provided by the invention, wherein the time of roasting is 1��60h, it is preferred to 2��30h.

According to method provided by the invention, wherein, when adopting catalyst to reclaim preparation vanadium tungsten titanio denitrating catalyst, can be used alone catalyst and reclaim powder, the catalyst of acquisition can also being reclaimed powder and fresh denitrating catalyst is prepared raw material and is sufficiently mixed, obtaining molding denitrating catalyst thus producing.

In the cleanout fluid of the present invention, blocking or the dirt such as covering catalyst surface and the silicon dioxide in duct, calcium sulfate can effectively be removed by the combination of JFC, OP-10, peregal and acid or alkali. Additionally, under the combined effect being combined in all the other components of JFC, OP-10, peregal and acid or alkali, it is also possible to effectively remove the poisoning material such as arsenic, phosphorus.

The recovery method of the SCR denitration of the present invention has the advantage that

The priority effect of (1) two kind of cleanout fluid (i.e. the first cleanout fluid and the second cleanout fluid) can effectively remove the various dirt in SCR denitration surface (such as, silicon dioxide, alchlor, calcium sulfate etc.) and multiple catalysts poisoning (such as, alkalinous metal, phosphorus, heavy metal arsenic, chromium poisoning) material;

(2) recovery method of the present invention can realize the secondary utilization of waste denitration catalyst, and recovery utilization rate is high, it is easy to concentrating and quickly process, the use of the fresh feed of catalyst is prepared in saving. Decreasing dangerous solid waste discharge, it is achieved that resource circulation utilization, reduce cost, save the energy, comprehensive benefit is high.

(3) the SCR denitration activity prepared by the inventive method is high, and stability is good.

Accompanying drawing explanation

Hereinafter, describe embodiment of the present invention in detail in conjunction with accompanying drawing, wherein:

Fig. 1 is the process chart of a kind of embodiment of the recycling method of the discarded vanadium tungsten titanio denitrating catalyst of the present invention.

Fig. 2 is the SO adopted in the present invention₃Concentration sampling analysis device schematic diagram;

Fig. 3 is catalyst run of the present invention and the graph of a relation of denitration rate.

Detailed description of the invention

Below in conjunction with detailed description of the invention, the present invention being further described in detail, the embodiment provided is only for illustrating the present invention, rather than in order to limit the scope of the present invention.

In the present invention, if not refering in particular to, all of part, percentage ratio are unit of weight, and the equipment adopted and raw material etc. all can be buied from market or conventional in this area.

Embodiment 1

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.001m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 1%, the sodium carbonate of 0.5%, 0.05% sodium ethylene diamine tetracetate, 0.05% diethylene-triamine pentaacetic acid sodium, 0.03% sodium citrate, 1% JFC, 0.01% OP-10, the peregal of 0.01%, the sodium pyrophosphate of 0.05% and surplus deionized water; With the formula of the second cleanout fluid be: the sulphuric acid of 3%, the citric acid of 0.5%, 0.1% tartaric acid, 0.01% ethylenediaminetetraacetic acid, 0.01% JFC, the OP-10 of 0.005%, the peregal of 1% and surplus deionized water. The first and second cleanout fluid are prepared, stirring 2h after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 2.5L step (2) is put into and ultrasonic washing unit heats to 40 DEG C, immersion 2h, ultrasonic cleaning 1h in ultrasonic washing unit put into by catalyst after the ash disposal that step (1) is prepared; Then, by the first cleanout fluid emptying, the second cleanout fluid injecting 2.5L is warming up to 40 DEG C, soaks 1h, ultrasonic cleaning 1h; Finally, catalyst is put into deionized water for ultrasonic and cleans 0.5h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard in step (4), baking temperature is 120 DEG C, and drying time is 10h.

(6), calcination process: dried catalyst in step (5) is put into roaster and carries out roasting, it is thus achieved that reclaimed materials, wherein, sintering temperature is 450 DEG C, and roasting time is 10h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 1200 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: denitrating catalyst fresh to the recovery powder obtained in 300g step (7) and 700g is prepared raw material (wherein, 591g titanium dioxide, 36g ammonium paratungstate, 8g ammonium metavanadate, 35g methylcellulose and 30g glass fibre) it is sufficiently mixed, use catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) to produce and obtain molding denitrating catalyst.

Embodiment 2

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.001m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 1%, the potassium hydroxide of 1%, 1% sodium carbonate, 0.05% sodium ethylene diamine tetracetate, 0.1% diethylene-triamine pentaacetic acid sodium, 0.05% sodium nitrilo triacetate, 0.1% sodium citrate, 0.1% JFC, 1% OP-10, the peregal of 0.1%, the sodium pyrophosphate of 0.1% and surplus deionized water; With the second cleanout fluid formula be: the sulphuric acid of 1%, the citric acid of 1%, 1% oxalic acid, 0.5% tartaric acid, 0.02% ethylenediaminetetraacetic acid, 0.1% nitrilotriacetic acid, 0.02% diethylene-triamine pentaacetic acid, 1% JFC, the OP-10 of 0.1%, the peregal of 0.5% and surplus deionized water. The first and second cleanout fluid are prepared, stirring 1h after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 1.5L step (2) is put into and ultrasonic washing unit heats to 30 DEG C, catalyst after ash disposal in step (1) is put into immersion 1h, ultrasonic cleaning 2h in ultrasonic washing unit; Then, by the first cleanout fluid emptying, the second cleanout fluid injecting 1.5L is warming up to 30 DEG C, soaks 1h, ultrasonic cleaning 2h; Finally, catalyst is put into deionized water for ultrasonic and cleans 1h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard through step (4), baking temperature is 140 DEG C, and drying time is 5h.

(6), calcination process: dried catalyst in step (5) is put into roaster and carries out roasting, it is thus achieved that reclaimed materials, wherein, sintering temperature is 500 DEG C, and roasting time is 8h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 800 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: denitrating catalyst fresh to the recovery powder obtained in 200g step (7) and 800g is prepared raw material (wherein, 645g titanium dioxide, 45g ammonium paratungstate, 10g ammonium metavanadate, 45g methylcellulose and glass fibre 55g) it is sufficiently mixed, use catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) to produce and obtain molding denitrating catalyst.

Embodiment 3

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.003m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 1%, the potassium hydroxide of 1%, 1% sodium carbonate, 0.05% sodium ethylene diamine tetracetate, 0.1% diethylene-triamine pentaacetic acid sodium, 0.05% sodium nitrilo triacetate, 0.1% sodium citrate, 0.1% JFC, 0.1% OP-10, the peregal of 1%, the sodium pyrophosphate of 0.1% and surplus deionized water; Second cleanout fluid formula is: the sulphuric acid of 5%, the citric acid of 1%, 0.02% ethylenediaminetetraacetic acid, 0.1% nitrilotriacetic acid, 0.02% diethylene-triamine pentaacetic acid, 0.1% JFC, the OP-10 of 1%, the peregal of 0.5% and surplus deionized water. Cleanout fluid is prepared, stirring 1h after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 12L step (2) is put into and ultrasonic washing unit heats to 50 DEG C, catalyst after ash disposal in step (1) is put into immersion 1h, ultrasonic cleaning 2h in ultrasonic washing unit; Then, by the first cleanout fluid emptying, the second cleanout fluid injecting 12L is warming up to 50 DEG C, soaks 1h, ultrasonic cleaning 2h; Finally, catalyst is put into deionized water for ultrasonic and cleans 2h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard through step (4), baking temperature is 120 DEG C, and drying time is 8h.

(6), calcination process: dried catalyst in step (5) being put into roaster and carries out roasting, it is thus achieved that reclaimed materials, sintering temperature is 500 DEG C, and roasting time is 5h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 1000 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: by the recovery powder obtained in 500g step (7) and 500g (wherein, 395g titanium dioxide, 27g ammonium paratungstate, 6g ammonium metavanadate, 32g methylcellulose and glass fibre 40g) it is sufficiently mixed, use catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) to produce and obtain molding denitrating catalyst.

Embodiment 4

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.003m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 2%, 1% sodium carbonate, 0.2% sodium ethylene diamine tetracetate, 0.1% diethylene-triamine pentaacetic acid sodium, 0.1% sodium nitrilo triacetate, 0.2% sodium citrate, 0.1% JFC, 0.1% OP-10,0.1% peregal, 1% sodium pyrophosphate and surplus deionized water; Second cleanout fluid formula is: the sulphuric acid of 3%, the citric acid of 1%, 0.5% ethylenediaminetetraacetic acid, 0.1% nitrilotriacetic acid, 1% diethylene-triamine pentaacetic acid, 0.1% JFC, the OP-10 of 0.1%, the peregal of 0.5% and surplus deionized water. Cleanout fluid is prepared, stirring 40min after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 8L step (2) is put into and ultrasonic washing unit heats to 60 DEG C, in step (1), immersion 2h, ultrasonic cleaning 2h in ultrasonic washing unit put into by the catalyst after ash disposal; Then, by the first clear cleanout fluid emptying, the second cleanout fluid injecting 8L is warming up to 60 DEG C, soaks 2h, ultrasonic cleaning 2h; Finally, catalyst is put into deionized water for ultrasonic and cleans 1h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard through step (4), baking temperature is 130 DEG C, and drying time is 8h.

(6), calcination process: dried catalyst in step (5) being put into roaster and carries out roasting, it is thus achieved that reclaimed materials, sintering temperature is 500 DEG C, and roasting time is 20h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 1200 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: denitrating catalyst fresh to the powder obtained in 600g step (7) and 400g is prepared raw material (338.5g titanium dioxide, 22g ammonium paratungstate, 4.5g ammonium metavanadate, 25g methylcellulose, 10g glass fibre) and is sufficiently mixed, use catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) to produce and obtain molding denitrating catalyst.

Embodiment 5

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.02m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 2%, 1% sodium carbonate, 0.15% sodium ethylene diamine tetracetate, 0.2% diethylene-triamine pentaacetic acid sodium, 1% sodium citrate, 0.01% JFC, 0.01% OP-10,0.01% peregal, 0.05% sodium pyrophosphate and surplus deionized water; With the second cleanout fluid formula be: the sulphuric acid of 2.5%, the citric acid of 0.5%, 0.5% tartaric acid, 0.5% nitrilotriacetic acid, 0.1% ethylenediaminetetraacetic acid, 0.1% JFC, the OP-10 of 0.2%, the peregal of 0.2% and surplus deionized water. Cleanout fluid is prepared, stirring 1h after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 40L step (2) is put into and ultrasonic washing unit heats to 40 DEG C, the catalyst of ash disposal in step (1) is put into immersion 1h, ultrasonic cleaning 2h in ultrasonic washing unit; Then, by the first clear cleanout fluid emptying, the second cleanout fluid injecting 60L is warming up to 40 DEG C, soaks 1h, ultrasonic cleaning 3h; Finally, catalyst is put into deionized water for ultrasonic and cleans 2h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard through step (4), baking temperature is 120 DEG C, and drying time is 8h.

(6), calcination process: dried catalyst in step (5) being put into roaster and carries out roasting, it is thus achieved that reclaimed materials, sintering temperature is 500 DEG C, and roasting time is 15h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 800 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: the powder obtained in 2000g step (7) and 7000g (6021g titanium dioxide, 365g ammonium paratungstate, 74g ammonium metavanadate, 300g methylcellulose, 240g glass fibre) are sufficiently mixed, use catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) to produce and obtain molding denitrating catalyst.

Embodiment 6

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.001m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 5%, the sodium carbonate of 0.1%, 1% sodium ethylene diamine tetracetate, 0.05% diethylene-triamine pentaacetic acid sodium, 0.03% sodium citrate, 0.01% JFC, 0.01% OP-10, the peregal of 0.01%, the sodium pyrophosphate of 0.05% and surplus deionized water; With the formula of the second cleanout fluid be: the sulphuric acid of 0.5%, the citric acid of 2%, 2% tartaric acid, 0.5% ethylenediaminetetraacetic acid, 0.01% JFC, the OP-10 of 0.01%, the peregal of 0.01% and surplus deionized water. The first and second cleanout fluid are prepared, stirring 2h after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 3L step (2) is put into and ultrasonic washing unit heats to 40 DEG C, immersion 2h, ultrasonic cleaning 1h in ultrasonic washing unit put into by catalyst after the ash disposal that step (1) is prepared; Then, by the first cleanout fluid emptying, the second cleanout fluid injecting 3L is warming up to 40 DEG C, soaks 1h, ultrasonic cleaning 1h; Finally, catalyst is put into deionized water for ultrasonic and cleans 0.5h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard in step (4), baking temperature is 120 DEG C, and drying time is 10h.

(6), calcination process: dried catalyst in step (5) is put into roaster and carries out roasting, it is thus achieved that reclaimed materials, wherein, sintering temperature is 450 DEG C, and roasting time is 10h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 1200 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: denitrating catalyst fresh to the recovery powder obtained in 500g step (7) and 700g is prepared raw material (wherein, 591g titanium dioxide, 36g ammonium paratungstate, 8g ammonium metavanadate, 35g methylcellulose and 30g glass fibre) it is sufficiently mixed, use catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) to produce and obtain molding denitrating catalyst.

Embodiment 7

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.001m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 0.5%, the sodium carbonate of 5%, 0.01% sodium ethylene diamine tetracetate, 1% diethylene-triamine pentaacetic acid sodium, 0.01% sodium citrate, 0.01% JFC, 0.01% OP-10, the peregal of 0.01%, the sodium pyrophosphate of 0.05% and surplus deionized water; With the formula of the second cleanout fluid be: the sulphuric acid of 15%, the ethylenediaminetetraacetic acid of 1%, 0.01% JFC, the OP-10 of 0.01%, the peregal of 0.01% and surplus deionized water. The first and second cleanout fluid are prepared, stirring 2h after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 2.5L step (2) is put into and ultrasonic washing unit heats to 30 DEG C, immersion 1h, ultrasonic cleaning 1.5h in ultrasonic washing unit put into by catalyst after the ash disposal that step (1) is prepared; Then, by the first cleanout fluid emptying, the second cleanout fluid injecting 2.5L is warming up to 25 DEG C, soaks 1h, ultrasonic cleaning 1h; Finally, catalyst is put into deionized water for ultrasonic and cleans 0.5h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard in step (4), baking temperature is 120 DEG C, and drying time is 10h.

(6), calcination process: dried catalyst in step (5) is put into roaster and carries out roasting, it is thus achieved that reclaimed materials, wherein, sintering temperature is 450 DEG C, and roasting time is 10h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 1200 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: denitrating catalyst fresh to the recovery powder obtained in 250g step (7) and 700g is prepared raw material (wherein, 591g titanium dioxide, 36g ammonium paratungstate, 8g ammonium metavanadate, 35g methylcellulose and 30g glass fibre) it is sufficiently mixed, use catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) to produce and obtain molding denitrating catalyst.

Embodiment 8

A kind of recycling method of discarded vanadium tungsten titanio denitrating catalyst, it specifically comprises the following steps that

(1), 0.001m is taken³Run more than the inactivation honeycomb type catalyst V of the 150mm �� 150mm �� 1100mm of 24000h₂O₅-WO₃/TiO₂Series catalysts carries out dedusting of negative pressure by negative-pressure vacuum equipment, with the dust in fully erased catalyst surface and duct.

(2), prepare the first cleanout fluid and the second cleanout fluid: the formula of the first cleanout fluid is: the sodium hydroxide of 2%, the sodium carbonate of 2%, 0.01% sodium ethylene diamine tetracetate, 0.05% diethylene-triamine pentaacetic acid sodium, 0.05% sodium nitrilo triacetate, 0.03% sodium citrate, 0.01% JFC, 0.01% OP-10, the peregal of 0.01%, the sodium pyrophosphate of 0.05% and surplus deionized water; With the formula of the second cleanout fluid be: the sulphuric acid of 3%, the citric acid of 1%, 1% tartaric acid, 0.5% ethylenediaminetetraacetic acid, 0.01% diethylene-triamine pentaacetic acid sodium, 0.01% sodium nitrilo triacetate, 0.01% JFC, the OP-10 of 0.01%, the peregal of 0.01% and surplus deionized water. The first and second cleanout fluid are prepared, stirring 2h after the mixing of each material by above-mentioned formula.

(3), cleaning catalyst: first, first cleanout fluid prepared by 3L step (2) is put into and ultrasonic washing unit heats to 40 DEG C, immersion 2h, ultrasonic cleaning 1h in ultrasonic washing unit put into by catalyst after the ash disposal that step (1) is prepared; Then, by the first cleanout fluid emptying, the second cleanout fluid injecting 3L is warming up to 40 DEG C, soaks 1h, ultrasonic cleaning 1h; Finally, catalyst is put into deionized water for ultrasonic and cleans 0.5h.

(4), detection is analyzed: the catalyst after step (3) is cleaned carries out elementary analysis, if iron sesquioxide (Fe in catalyst₂O₃), arsenic trioxide (As₂O₃), sodium oxide (Na₂And potassium oxide (K O)₂O) content is below 0.001wt% and phosphorus pentoxide (P₂O₅) content lower than 0.01wt%, then up to standard, carry out next step operation, otherwise, then repeat step (3).

(5), dried: being dried process by detecting catalyst up to standard in step (4), baking temperature is 120 DEG C, and drying time is 10h.

(6), calcination process: dried catalyst in step (5) is put into roaster and carries out roasting, it is thus achieved that reclaimed materials, wherein, sintering temperature is 450 DEG C, and roasting time is 10h.

(7), pulverization process: the reclaimed materials after roasting in step (6) is crushed to 1200 orders, it is thus achieved that catalyst reclaims powder.

(8), catalyst preparing: the recovery powder obtained in 500g step (7) uses catalysis former (the vertical sleeping extruder of LWJ70 type vacuum) produce and obtains molding denitrating catalyst.

Embodiment 9

The catalyst and the catalyst prepared by fresh feed completely that use the preparation of embodiment 1��8 carry out catalyst activity contrast the oxidation rate of sulfur dioxide of testing catalytic agent.

1. test method

Catalyst is evaluated in 316L rustless steel fixed bed reactors. Reactor apparatus with catalyst inside filling basket, loads basket apparatus with catalyst inside. For preventing flue gas short circuit, the gap between catalyst and filling basket, between filling basket and reaction tube seals with silica wool. It is respectively provided with thermocouple in Catalyst packing basket upper and lower, with the temperature of test reactor, adopts N4440 type WEST precision temperature controller to control temperature of reactor.

Test adopts steel cylinder gas simulative power plant flue gas. Its composition is respectively as follows: N₂��O₂��CO₂��H₂O (gaseous state), 5 volume %NO+N₂, 5 volume %SO₂+N₂. Owing in typical case's flue gas, NO accounts for NO_xMore than the 95% of volume, NO₂Impact only small, it is possible to ignore, thus in test adopt NO replace NO_x. Wherein, with volume fraction, the composition of experimental condition flue gas is as follows: 200ppmNO, 200ppmNH₃��800ppmSO₂, 3.9%O₂, 13.5%CO₂, 12.5%H₂O and aequum N₂, air speed controls at 4500h^-1Left and right, reaction temperature controls at 350 DEG C.

Each gas component controls to enter after metering preheating mixer through mass flowmenter; Deionized water, through U.S.'s ELDEX brand P-81 type micro-precision dosing pump, adds steam after entering preheating mixer vaporization; Reducing agent 5 volume %NH₃+N₂Add before ammonia blender.

NO, SO in flue gas₂��O₂Concentration adopts silent your the on-line continuous flue gas analyzer of generation that flies of match to detect. SO₃Concentration adopts U.S. Environmental Protection Agency (EPA) M8 method manual sampling to analyze, with reference to Fig. 2, particularly as follows: absorb SO in flue gas by isopropanol₃, record exhaust gas volumn, carry out titrimetry by thorium indicator barium chloride.

2. denitration rate

Calculating denitration rate according to formula (I), result is in Table 1.

$\·\mathrm{\η}=\frac{{\[{\mathrm{NO}}_X\]}_{in}-{\[{\mathrm{NO}}_X\]}_{out}}{{\[{\mathrm{NO}}_X\]}_{in}}\×100\%---\left(I\right)$

In formula (I):

�� is catalyst denitration rate, %;

[NO_x]_inFor reactor inlet NO_xVolumetric concentration, ppm;

[NO_x]_outFor reactor outlet NO_xVolumetric concentration, ppm.

3. catalyst activity:

Catalyst activity is calculated according to formula (II), and the catalyst activity that the catalyst prepared of the compound calculating catalyst prepared by fresh feed and embodiment 1��5 is prepared relative to fresh feed, namely, relative activity (K/Ko), wherein Ko is the activity of catalyst prepared by fresh feed, and result is in Table 1.

$\·K=0.5\×\frac{Q}{V\×A_p}\×\ln \frac{MR}{(MR-\mathrm{\η})\×(1-\mathrm{\η})}---\left(II\right)$

In formula (II):

K is catalyst activity, m/h;

Q is flue gas flow, m³/ h;

V is catalyst volume, m³;

A_pFor catalyst geometric proportion surface area, m²/m³;

�� is catalyst denitration rate, %;

MR is ammonia nitrogen mol ratio.

4.SO₂/SO₃Oxygenation efficiency

Calculating catalyst activity by formula (III), result is in Table 1.

$\·K_{2/3}=\frac{{\[{\mathrm{SO}}_3\]}_{out}-{\[{\mathrm{SO}}_3\]}_{in}}{{\[{\mathrm{SO}}_2\]}_{in}}\×100\%---\left(III\right)$

In formula (III):

K_2/3For SO₂Oxygenation efficiency, %;

[SO₃]_inFor reactor inlet SO₃Volumetric concentration, ppm;

[SO₃]_outFor reactor outlet SO₃Volumetric concentration, ppm;

[SO₂]_inFor reactor inlet SO₂Volumetric concentration, ppm.

Table 1 catalyst performance test result

Catalyst sample	Denitration rate (%)	Relative activity (K/Ko)	SO2/SO3Oxygenation efficiency (%)
				Fresh catalyst	95.0	-	0.82
Embodiment 1	95.2	1.01	0.80
				Embodiment 2	94.5	0.97	0.76
Embodiment 3	93.8	0.93	0.77
				Embodiment 4	94.4	0.96	0.80
Embodiment 5	95.8	1.06	0.81
				Embodiment 6	94.3	0.95	0.72
Embodiment 7	96.1	1.08	0.61
				Embodiment 8	94.1	0.94	0.87

As it can be seen from table 1 result shows, the present invention utilize catalyst prepared by reclaimed materials can denitration performance good.

Fig. 3 shows the catalyst 3000h life assessment result figure of preparation in embodiment 1, and this catalyst denitration rate within the investigation time of 3000h is stable about 95%. Thus, catalyst stability of the present invention is good.

Claims (9)

1. a recycling method for discarded vanadium tungsten titanio denitrating catalyst, said method comprising the steps of:

(1) cleaning of discarded vanadium tungsten titanio denitrating catalyst: adopt the first cleanout fluid and the second cleanout fluid that discarded vanadium tungsten titanio denitrating catalyst is carried out successively, until iron sesquioxide in catalyst, arsenic trioxide, the content of sodium oxide and potassium oxide is below 0.001wt%, and the content of phosphorus pentoxide is lower than 0.01wt%, wherein, described first cleanout fluid comprises sodium hydroxide and/or the potassium hydroxide of 0.01��5wt%, the sodium carbonate of 0.01��5wt%, the sodium ethylene diamine tetracetate of 0.001��2wt%, the diethylene-triamine pentaacetic acid sodium of 0.001��2wt%, the sodium nitrilo triacetate of 0��2wt%, the sodium citrate of 0.001��1wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt%, the water of 0.001��1wt% sodium pyrophosphate and surplus, with the water that described second cleanout fluid comprises the sulphuric acid of 0.01��15wt%, the citric acid of 0.01��2wt%, the oxalic acid of 0��2wt%, the tartaric acid of 0��2wt%, the ethylenediaminetetraacetic acid of 0.001��1wt%, the nitrilotriacetic acid of 0��0.5wt%, the diethylene-triamine pentaacetic acid of 0��2wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt% and surplus,

(2) dry: the catalyst that step (1) is obtained is dried;

(3) roasting: catalyst roasting at 300-600 DEG C that step (2) is obtained, it is thus achieved that reclaimed materials.

2. a recycling method for discarded vanadium tungsten titanio denitrating catalyst, said method comprising the steps of:

(1) cleaning of discarded vanadium tungsten titanio denitrating catalyst: adopt the first cleanout fluid and the second cleanout fluid that discarded vanadium tungsten titanio denitrating catalyst is carried out successively, until iron sesquioxide in catalyst, arsenic trioxide, the content of sodium oxide and potassium oxide is below 0.001wt%, and the content of phosphorus pentoxide is lower than 0.01wt%, wherein, described first cleanout fluid comprises sodium hydroxide and/or the potassium hydroxide of 0.01��5wt%, the sodium carbonate of 0.01��5wt%, the sodium ethylene diamine tetracetate of 0.001��2wt%, the diethylene-triamine pentaacetic acid sodium of 0.001��2wt%, the sodium nitrilo triacetate of 0��2wt%, the sodium citrate of 0.001��1wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt%, the sodium pyrophosphate of 0.001��1wt% and the water of surplus, with the water that described second cleanout fluid comprises the sulphuric acid of 0.01��15wt%, the citric acid of 0.01��2wt%, the oxalic acid of 0��2wt%, the tartaric acid of 0��2wt%, the ethylenediaminetetraacetic acid of 0.001��1wt%, the nitrilotriacetic acid of 0��0.5wt%, the diethylene-triamine pentaacetic acid of 0��2wt%, the JFC of 0.001��1.5wt%, the OP-10 of 0.001��1.5wt%, the peregal of 0.001��1.5wt% and surplus,

(2) dry: the catalyst that step (1) is obtained is dried; With

(3) roasting: catalyst roasting at 300-600 DEG C that step (2) is obtained, it is thus achieved that reclaimed materials;

(4) pulverizing: pulverized by the reclaimed materials after roasting in step (3), the catalyst preparing 500-2000 order reclaims powder; With

(5) catalyst is prepared: the catalyst obtained in step (4) is reclaimed powder and makes vanadium tungsten titanio denitrating catalyst.

3. method according to claim 1 and 2, wherein, described method also includes: before cleaning step, first discarded vanadium tungsten titanio denitrating catalyst is carried out dedusting of negative pressure, it is preferable that described dedusting of negative pressure is to carry out under the vacuum of 20��45kPa.

4. according to the method in any one of claims 1 to 3, wherein, in the first cleanout fluid described in described step (1), the content of sodium nitrilo triacetate is 0.001��2wt%; The content of described second cleanout fluid mesoxalic acid is 0.01��2wt%, and the content of nitrilotriacetic acid is 0.001��0.5wt%'s and diethylene-triamine pentaacetic acid content is 0.001��2wt%;

Preferably, described first cleanout fluid comprises the water of the sodium hydroxide of 0.5��5wt% and/or potassium hydroxide, the sodium carbonate of 0.1��5wt%, the sodium ethylene diamine tetracetate of 0.01��1wt%, the diethylene-triamine pentaacetic acid sodium of 0.05��1wt%, the sodium nitrilo triacetate of 0.001��0.1wt%, the sodium citrate of 0.01��1wt%, the JFC of 0.01��1wt%, the OP-10 of 0.01��1wt%, the peregal of 0.01��1wt%, the sodium pyrophosphate of 0.05��1wt% and surplus; It is further preferable that described first cleanout fluid comprises the sodium hydroxide of 1��3wt% and/or the sodium carbonate of potassium hydroxide and 0.5��3wt%;

Preferably, described second cleanout fluid comprise the sulphuric acid of 0.5��15wt%, the citric acid of 0.01��2wt%, the oxalic acid of 0.01��1wt%, 0��2% tartaric acid, the ethylenediaminetetraacetic acid of 0.01��1wt%, the nitrilotriacetic acid of 0.01��0.5wt%, the diethylene-triamine pentaacetic acid of 0��1wt%, the JFC of 0.01��1wt%, the OP-10 of 0.005��1wt%, the peregal of 0.01��1wt% and surplus water; It is further preferable that described second cleanout fluid comprises the oxalic acid of the sulphuric acid of 0.5��5wt%, the citric acid of 0.1��1wt% and 0.1��0.8wt%.

5. method according to any one of claim 1 to 4, wherein, described in described step (1), the consumption of the first cleanout fluid and described second cleanout fluid is each independently the every 0.001m of 1.2��5L cleanout fluid³Catalyst, it is preferred to the every 0.001m of 1.5��4L cleanout fluid³Catalyst.

6. method according to any one of claim 1 to 5, wherein, cleaning operation in described step (1) includes: first discarded vanadium tungsten titanio denitrating catalyst is soaked in the first cleanout fluid such as 60��120min, ultrasonic waves for cleaning is or/and pressure pulse cleaning such as 15��480min, preferred 30-240min, more preferably 60��120min; But discarded vanadium tungsten titanio denitrating catalyst is soaked such as 60��120min in the second cleanout fluid, ultrasonic waves for cleaning is or/and pressure pulse cleaning such as 15��480min, it is preferable that 30��240min, more preferably 60��120min;

Preferably, described method also includes: after adopting the first cleanout fluid and the second cleanout fluid that discarded vanadium tungsten titanio denitrating catalyst is carried out, catalyst is carried out deionized water cleaning.

7. method according to any one of claim 1 to 6, wherein, adopting the temperature that discarded vanadium tungsten titanio denitrating catalyst is carried out by the first cleanout fluid and the second cleanout fluid in described step (1) is 10��90 DEG C, it is preferred to 20��60 DEG C, more preferably 30��60 DEG C.

8. method according to any one of claim 1 to 7, wherein, temperature dry described in described step (2) is 60��200 DEG C, it is preferred to 80��120 DEG C, the time is 1��48h, it is preferred to 2��30h.

9. method according to any one of claim 1 to 8, wherein, in described step (3), the temperature of roasting is 300��500 DEG C, it is preferred to 350��500 DEG C;

Preferably roasting time is 1��60h, it is preferred to 2��30h.