Vanadium and tungsten separating and purifying method for spent vanadium and tungsten SCR (selective catalytic reduction) catalysts

A technology of SCR catalyst, vanadium and tungsten, applied in the field of solid waste treatment, can solve the problems of not fully considering the separation steps and removal methods of impurities, not involving the secondary utilization of heat energy of calcination tail gas, and unable to realize the effective separation and purification of vanadium and tungsten , to achieve good economic benefits, low cost, and low drug consumption

Active Publication Date: 2015-08-26
BOTREE CYCLING SCI &TECH CO LTD
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

In these three patents, since the material needs to be pulverized before sodium roasting, the pulverized particle size is required to be ≤200μm. If it is not granulated, serious fly ash loss and a large amount of CO will occur during the calcination process. 2 Emissions; there is no description of the full use of heat energy, especially not involving the secondary utilization of the heat energy of the material after high-temperature sodium roasting and the heat energy of the calcination tail gas; the separation steps and removal methods of various impurities in the SCR waste catalyst are not fully considered. Realize the effective separation and purification of vanadium and tungsten, so the recovery rate of vanadium and tungsten technology and the purity of the obtained products are limited

Method used

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  • Vanadium and tungsten separating and purifying method for spent vanadium and tungsten SCR (selective catalytic reduction) catalysts

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] Waste vanadium-tungsten based SCR catalyst provided by a laboratory, V 2 o 5 The content is 1.5%, WO 3 4.5%, TiO 2 94%.

[0050] (1) Take the above spent catalyst, press m add :m metal Add additive NaOH at a ratio of = 1, then mix evenly and place in a muffle furnace to roast for conversion and removal of impurities, the roasting temperature is 600°C, and the roasting time is 3 hours; pure water is used as the leaching agent to extract vanadium and molybdenum from the roasted solid phase product, The liquid-solid ratio is 0.02L / g, the leaching temperature is 20°C, and the leaching time is 0.5h. The single-stage leaching rate of vanadium is 78%, and that of tungsten is 72%. After filtration, the residue is recovered;

[0051] (2) Use an extraction system composed of 5% primary amine extractant JMT and kerosene as the organic phase to conduct a one-stage extraction and separation of V and W in the vanadium-tungsten leach solution, O / A=1, initial pH of the aqueous pha...

Embodiment 2

[0058] Waste vanadium-tungsten based SCR catalyst provided by a laboratory, V 2 o 5 The content is 1.3%, WO 3 4.6%, TiO 2 It was 94.1%.

[0059] (1) Take the above spent catalyst, press m add :m metal =1.4, add the additive KOH, then mix evenly and place in a muffle furnace to roast for conversion and removal of impurities, the roasting temperature is 500°C, and the roasting time is 1h; pure water is used as the leaching agent, and vanadium and molybdenum are leached from the solid phase product after roasting. The liquid-solid ratio is 0.02L / g, the leaching temperature is 25°C, and the leaching time is 1h. The single-stage leaching rate of vanadium is 82%, and that of tungsten is 75%. After filtration, the residue is recovered;

[0060] (2) Use an extraction system composed of 10% neutral phosphine extractant TBP and kerosene as the V and W in the organic phase vanadium-tungsten leaching solution to perform a one-stage extraction and separation, O / A=1, the initial pH of ...

Embodiment 3

[0067] Waste vanadium-tungsten based SCR catalyst provided by a laboratory, V 2 o 5 The content is 1.7%, WO 3 4.8%, TiO 2 93.5%.

[0068] (1) Take the above spent catalyst, press m add :m metal =1.6 ratio, add NaOH, then mix evenly and put it in a muffle furnace for roasting to transform and remove impurities. The liquid-solid ratio is 0.025L / g, the leaching temperature is 45°C, and the leaching time is 1h. The single-stage leaching rate of vanadium is 83%, and that of molybdenum is 77%. After filtration, the residue is recovered;

[0069] (2) Use an extraction system composed of 15% primary amine extractant JMT and kerosene as the organic phase to conduct a one-stage extraction and separation of V and W in the vanadium-tungsten leach solution, O / A=1, the initial pH of the aqueous phase=0, and the extraction temperature The temperature is 20°C, the extraction time is 30min, the W extraction rate is 100%, and the V extraction rate is 45%;

[0070] (3) The vanadium-rich r...

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Abstract

The invention discloses a vanadium and tungsten separating and purifying method for spent vanadium and tungsten SCR (selective catalytic reduction) catalysts. The method comprises the following steps: a spent catalyst is pretreated to obtain titanium slag and a vanadium and tungsten solution; the vanadium and tungsten solution is extracted for separation, and an obtained vanadium-rich raffinate is treated again to obtain vanadium pentoxide; a tungsten-rich organic phase obtained through separation is subjected to two-stage extraction for tungsten extraction after back extraction, a product is subjected to back extraction again to obtain an ammonium tungstate solution, and the ammonium tungstate solution is treated to prepare ammonium paratungstate. The blank of lack of a vanadium and tungsten separating, purifying and recovering technology for the spent vanadium and tungsten SCR catalysts in the denitration industry is filled up completely, the recovery rates of vanadium and tungsten both exceed 95%, the obtained vanadium pentoxide and ammonium paratungstate products all meet the high-purity standard, and the purity is higher than 99%.

Description

technical field [0001] The invention belongs to the field of solid waste treatment, in particular to a method for separating and purifying vanadium and tungsten of spent vanadium and tungsten-based SCR catalysts. Background technique [0002] my country is a big country in energy production and consumption. The energy supply is dominated by coal, and oil and natural gas resources are in short supply. Coal-fired power generation is mainly through direct combustion. Coal combustion produces a large amount of soot, nitrogen oxides (NOx), sulfur oxides (SOx), mercury and other heavy metal oxides and a large amount of carbon dioxide gas. [0003] Nitrogen oxides (NOx) are one of the main air pollutants, which can cause acid rain, photochemical smog, reduction of stratospheric ozone and increase of near-surface ozone concentration. How to effectively control NOx emissions has become an important topic of concern in current environmental protection. Among many denitrification tec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B34/22C22B34/36
CPCY02P10/20
Inventor 林晓刘晨明潘尹银李志强
Owner BOTREE CYCLING SCI &TECH CO LTD
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