Vanadium pentoxide is an intermediate product for the production of metal vanadium, ferrovanadium alloy and other vanadium based alloys. It is also a raw material for the manufacture of vanadium catalyst. It can be used as a catalyst for organic synthesis such as benzoic acid and phthalic acid, as well as for the manufacture of colored glass and ceramics.
Vanadium pentoxide is an amphoteric oxide, which is more acidic than alkaline. It dissolves in strong alkali to form vanadate, and dissolves in strong acid to form vanadium oxide ion VO or VO3 +. Orange or brick red solid. Odorless, tasteless and toxic. Slightly soluble in water to form light yellow acid solution. Vanadium pentoxide can be prepared by the thermal decomposition of ammonium metavanadate or the reaction of vanadium oxychloride with water.
Pengfei group successfully developed vanadium pentoxide rotary kiln, realized the industrial production of vanadium pentoxide product preparation, and promoted the technical progress of the industry. Production process of vanadium pentoxide rotary kiln: waste catalyst → crushing → hydrochloric acid leaching → filtration → hydrolysis with sodium hydroxide → vanadium precipitation → refining → calcination → product. The process flow is simple and the recovery rate is more than 90%.
Introduction to recovery process of vanadium pentoxide rotary kiln:
1. Recovery from vanadium slag: vanadium slag is a raw material for vanadium extraction with high vanadium content, and the recovery technology is relatively mature. At present, the general process is sodium roasting process, with different equipment. Large enterprises generally use rotary kiln, while some enterprises use roasting furnace. The process is to combine vanadium slag with sodium salt (generally sodium carbonate or mirabilite) is mixed and roasted at a certain temperature to turn vanadium into soluble sodium salt. The calcine is leached to make vanadate enter the solution. The solution is filtered, the waste residue is filtered, and then vanadium pentoxide is obtained through precipitation and refinement. Foreign enterprises directly use vanadium titanomagnetite with high vanadium content to produce vanadium pentoxide. First, the ore is made into vanadium pentoxide The concentrate is then mixed with flux and roasted in a rotary kiln. The calcine is leached with water. The vanadium containing solution is treated with ammonium salt, and finally ammonium metavanadate is precipitated.
2. Recovery from stone coal: the process of extracting vanadium from stone coal mainly includes sodium roasting process, sodium oxidation roasting - water leaching - hydrolysis vanadium precipitation - alkali soluble ammonium salt vanadium precipitation - pyrolysis ammonia removal - refined vanadium. This process is widely used to extract vanadium from stone coal in China. It is characterized by simple process and makes full use of the heat energy of stone coal. The disadvantage is that the recovery rate is low, generally below 60%. The above process is adopted in the United States, but dilute sulfuric acid leaching and solvent extraction technology are adopted, and the recovery rate can reach 70%.
3. Recovery from spent petroleum catalysts: the United States, Japan and other countries began to recover vanadium from spent petroleum catalysts containing vanadium in the 1970s. The technology has been mature, there are many processing processes, and many processes have been patented.
Sodium roasting method:
Batching → roasting → grinding → leaching and filtration → vanadium precipitation → calcination → vanadium pentoxide products
↓
Solution → extraction and recovery of molybdenum → ammonium molybdate product
↓
Slag → further recovery of nickel → metal nickel.
Although the economic and technical parameters in the recovery process are different, they basically refer to the above processes, and the processes adopted by Chinese enterprises recovering vanadium from waste catalysts in the petroleum industry are basically the same.
4. Recovery from waste catalyst in sulfuric acid industry: the recovery of vanadium pentoxide from waste catalyst in sulfuric acid industry has long attracted the attention of countries all over the world. The former Soviet Union started earlier and the technology is relatively mature. There are many patent reports in Japan and the United States. The recovery of vanadium from waste vanadium catalyst in sulfuric acid industry in China was carried out earlier. At present, the technologies used include pyrometallurgical wet combined process and all wet process, which are widely used.
The production process of vanadium pentoxide rotary kiln is as follows:
Waste catalyst → crushing → hydrochloric acid leaching → filtration → hydrolysis with sodium hydroxide → vanadium precipitation → refining → calcination → product. The process flow is simple and the recovery rate is more than 90%. The rotary kiln roasting method is used to extract vanadium from vanadium pentoxide. The roasting high temperature section is 720 ~ 800 ℃, and a certain amount of sodium carbonate is added to the vanadium slag to achieve the best conversion rate. The residence time of the ore at about 930 ℃ in the high temperature section should be maintained at 5 ~ 6 hours. The rotary kiln should be burned normally. The minimum high temperature point should not be lower than 1100 ℃, and the melting point of the ore should not exceed 1000 ℃. From the analysis of the above roasting methods, it can be seen from the analysis of vanadium pentoxide roasting process at this stage that the roasting of vanadium pentoxide in rotary kiln is a relatively advanced and feasible technology, which should be vigorously popularized and applied. Jiangsu Pengfei group has successfully developed a vanadium pentoxide roasting rotary kiln to realize the industrial production of vanadium pentoxide product preparation and promote the technical progress of the industry.
Pengfei group's main products include:
Building materials: complete sets of technologies and equipment such as cement, lime, high phosphorus soil and aluminum vanadium soil;
Metallurgy: laterite nickel ore roasting kiln, lithium ore roasting kiln, gold ore smelting kiln, iron chromium reduction kiln, copper mine shaft furnace, steel pellet, magnetization roasting rotary kiln, large ore mill, vertical coal mill, etc;
Chemical industry: calcium carbonate, titanium dioxide, vanadium pentoxide rotary kiln, zinc oxide rotary kiln, alumina complete set technology and equipment, composite powder complete set technology and equipment, nitriding furnace, coal efficient clean quality improvement kiln, coal to oil, coal clean dry distillation technology and equipment, oil sand oil shale oil extraction technology and equipment;
Environmental protection: solid waste, hazardous waste, sludge disposal kiln, cement kiln collaborative waste disposal technology and equipment;
Vanadium pentoxide, alias: alum anhydride; Vanadium (acid) anhydride; Alum pentoxide; Alum oxide; Vanadium oxide; Anhydrous vanadic acid; Vanadium pentoxide; Vanadium oxide (V)
English name:Vanadium pentoxide
English alias:C.I. 77938; Vanadium pentoxide; Anhydride vanadique; anhydridevanadique; anhydridevanadique(french); divanadiumpentoxide; divanandiumpentoxide; KM vanadium pentoxide; Rcra waste number P120; rcrawastenumberp120
Appearance and properties of vanadium pentoxide: orange yellow, brick red, red brown crystalline powder or gray black flake. Slightly soluble in water, insoluble in ethanol, soluble in strong acid and alkali. Significant volatilization above 700 ℃. It is decomposed into oxygen and vanadium tetroxide at 700 ~ 1125 ℃, which makes it a catalyst for many organic and inorganic reactions. As a strong oxidant, it is easy to be reduced to various low-cost oxides. Slightly soluble in water, easy to form a stable colloidal solution. It is very soluble in alkali and can form vanadate (VO3) under weakly alkaline conditions. Soluble in strong acid (generally soluble at pH = 2) does not generate vanadate ions, but generates oxyvanadium ions (VO2) in the same valence state. It is a toxic substance, and the maximum allowable amount in the air is less than 0.5mg/m. Fire and explosion hazard: This product is non combustible and highly toxic. Harmful to respiratory system and skin. Acute poisoning: it can cause irritation of nose, pharynx and lungs. The contact person has burning eyes, tears, pharyngeal itching, dry cough, chest tightness, general discomfort, fatigue and other manifestations, and in severe cases, bronchitis or bronchopneumonia. High concentration skin contact can cause dermatitis and severe itching. Long term exposure can cause chronic poisoning such as chronic bronchitis, kidney damage and visual impairment. It is formed by the thermal decomposition of ammonium metavanadate or the hydrolysis of vanadium chloride. Depending on the preparation method and conditions, vanadium pentoxide can be yellow, orange, brick red or brown.
