阅读说明：本技术 低温型湿法转化制硫酸钒催化剂制备方法 (Preparation method of low-temperature catalyst for preparing vanadium sulfate by wet conversion ) 是由 孙远龙 袁浩然 吴结华 张觅 于 2018-06-25 设计创作，主要内容包括：本发明属于催化剂技术领域,具体涉及一种低温型湿法转化制硫酸钒催化剂制备方法。一种低温型湿法转化制硫酸钒催化剂制备方法,其特征在于制备催化剂活性相时加入硅溶胶,再与碱金属硫酸盐、助剂、精制硅藻土等加入碾子中混合均匀、碾压紧密,再经挤条、干燥、焙烧等工序制成催化剂成品。利用该方法制备的催化剂具有抗粉化、强度高、活性稳定性好等特征。(The invention belongs to the technical field of catalysts, and particularly relates to a preparation method of a catalyst for preparing vanadium sulfate by low-temperature wet conversion. A process for preparing vanadium sulfate catalyst by low-temp wet conversion includes such steps as adding silica sol, alkali metal sulfate, assistant and refined diatomite, mixing, rolling, extruding, drying and calcining. The catalyst prepared by the method has the characteristics of pulverization resistance, high strength, good activity stability and the like.)

1. A process for preparing vanadium sulfate catalyst by low-temp wet conversion includes such steps as adding silica sol, mixing with alkali metal sulfate, assistant and refined diatomite, rolling, extruding, drying and calcining.

2. The process for preparing a catalyst according to claim 1, wherein the silica sol solution has a mean particle size of 5 nm ~ 50nm and a pH of 8 ~ 11.

3. The process for preparing a catalyst according to claim 1, wherein the silica sol is a JA or JN type silica sol.

4. The process for preparing the catalyst according to claim 1, wherein SiO in the silica sol₂The content of the catalyst accounts for 5 ~ 10 percent of the mass of the catalyst.

5. The process for preparing a catalyst according to claim 1, wherein the auxiliary agent is methylcellulose.

6. The process for preparing the catalyst of claim 1, wherein the calcination temperature is 450 ℃ and ~ 500 ℃ and N is introduced thereinto₂Calcining for 30 ~ 40 min, and introducing SO₂The roasting time is 40 ~ 50 minutes, and finally air is introduced at 600 ℃ of ~ 650 ℃ for 50 ~ 60 minutes.

7. The method of claim 6, wherein SO is present during calcination₂The content was 6 ~ 9%.

Technical Field

The present invention relates to a method for producing a catalyst. In particular to a preparation method of a catalyst for preparing vanadium sulfate by low-temperature wet conversion.

Background

The wet contact method for preparing acid is to catalytically convert sulfur dioxide into sulfur trioxide in the presence of water vapor without washing and drying, and the sulfur dioxide is directly condensed into acid. Obviously, the wet contact method for preparing acid is simpler in process and more beneficial to recycling of system energy. Most hydrogen sulfide sources are relatively clean, so the wet contact method acid preparation process is widely applied. The wet acid making process is the most economical choice. Meanwhile, in many cases, sulfur is not a product required by users, hydrogen sulfide is an attractive option for preparing acid, and a plurality of process procedures can be omitted by using hydrogen sulfide for preparing acid, so that the investment and the production cost are reduced, and the product has stronger market competitiveness.

In the prior art, the production process flow of the domestic catalyst for preparing sulfuric acid by oxidizing sulfur dioxide comprises the following steps: refining diatomite; dissolving vanadium pentoxide, alkali metal mother liquor and other auxiliary agents; neutralizing with sulfuric acid; the neutralized substance is mixed with refined diatomite and other assistants, and then the mixture is formed, dried and calcined.

The wet conversion process for preparing acid from hydrogen sulfide features that the raw material gas contains lots of water vapour. The catalytic oxidation of sulfur dioxide is carried out under conditions that contain a large amount of water vapor. The catalyst prepared by the prior art cannot meet the wet process, the traditional vanadium-silicon catalyst is seriously pulverized, and the pressure drop is increased after the catalyst is used for a period of time. And the import operation temperature of the catalyst for preparing acid by the domestic wet contact method is generally between 410 and 420 ℃. However, as the environmental protection requirements become more stringent, the catalyst is required to have better low-temperature activity.

Disclosure of Invention

The invention aims to provide a preparation method of a catalyst for preparing vanadium sulfate by low-temperature wet conversion. The catalyst prepared by the method has the advantages of pulverization resistance, high strength, good low-temperature activity and good stability.

The invention relates to a preparation method of a vanadium sulfate catalyst by low-temperature wet conversion, which is characterized in that silica sol is added when preparing an active phase of the catalyst, then the active phase of the catalyst is uniformly mixed with alkali metal sulfate, an auxiliary agent and refined diatomite, and the mixture is rolled, compacted and extruded, dried, roasted and the like to prepare a finished catalyst product.

Preferably, the average particle diameter of the colloidal particles of the silica sol solution is 5 nm ~ 50nm, and the pH value is 8 ~ 11.

SiO in the silica sol₂The content of the catalyst accounts for 5 ~ 10 percent of the mass of the catalyst.

The silica sol is JA or JN type silica sol.

The auxiliary agent is methyl cellulose.

The roasting temperature is 450 ℃, ~ 500 ℃ and N is introduced₂Calcining for 30 ~ 40 min, and introducing SO₂The roasting time is 40 ~ 50, and finally air is introduced at 600 ℃ of ~ 650 ℃ and 650 ℃ to roast for 50 ~ 60 minutes.

SO during the roasting₂The content was 6 ~ 9%.

The catalyst prepared by the method has the advantages of pulverization resistance, high strength, good activity stability and the like.

Detailed Description

The present invention will be further described with reference to the following examples.