Method for direct production of phosphorus pentoxide with phosphorus ore

Abstract

The invention discloses a production method of phosphorus pentoxide by directly using phosphorus ore. Phosphorus ore and silica are mixed pro rata, delivered to a heating furnace to be heated and molten, after the molten mass flows into a reaction furnace, carbon is directly added into the high temperature molten mass, the carbon is kept to be excess, the temperature of the molten mass is controlled above 1200 DEG C, thereby leading the molten mass to generate reducing reaction, high temperature and high speed oxygen is sprayed downward into the molten mass through an upper spray gun, thereby providing oxygen for the oxidation of phosphorus vapor and carbon monoxide generated in the reducing zone, and a dished high temperature zone can be formed on the surface of the center of the molten mass, therefore, the heat transfer rate of the mass transfer in the reduction oxidation zone is greatly intensified, the finished quality is ensured, the percent reduction of the phosphorus ore is improved, and the continuous phosphorus pentoxide and phosphonic acid production can be realized. The invention has the advantages that the flow is simplified, the cost is reduced, the finished quality is improved, the percent reduction of the phosphor reaches 98 percent, the energy and resource are saved, the three wastes are basically eliminated, therefore, the invention provides the epoch-making revolution for the phosphor chemical engineering industry.

Description

technical field [0001] The invention belongs to the technical field of phosphorus chemical industry and specifically introduces a method for producing phosphorus pentoxide by directly heating and melting medium and low-grade phosphate rocks. Background technique [0002] Phosphorus pentoxide is the acid anhydride of phosphoric acid and is an important intermediate for the production of phosphoric acid. At present, the production process of phosphorus pentoxide in the world is to oxidize and burn yellow phosphorus in dry air to generate high-temperature phosphorus pentoxide vapor. The vapor is precipitated after cooling to obtain phosphorus pentoxide product. [0003] In industry, phosphorus pentoxide is hydrated to generate phosphoric acid, and phosphorus pentoxide is a synonym for phosphoric acid. In order to understand the technical background of the present invention, it is necessary to introduce the production method of phosphoric acid. [0004] At present, there are th...

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Problems solved by technology

[0006] The production cost of wet-process phosphoric acid is low, but it consumes a lot of sulfuric acid. my country is a country lacking in sulfur resources. It imports a large amount of sulfur from abroad every year. The continuous price increase of sulfur has seriously threatened the survival and development of my country's phosphorus chemical industry and phosphate fertilizer industry. ; At the same time, in the production process of wet-process phosphoric acid, a large amount of phosphogypsum will be produced, occupying land and polluting the environment; secondly, wet-process phosphoric acid production can only use P 2 o 5 >28% of high-grade phosphate rock, my country is a country that is poor in phosphate rock, resulting in a large number of phosphate rock mining abandoning the poor and exploiting the rich, and the mining rate of the mine is less than 30%, which is a serious waste of my country's phosphorus resources. Finally, phosphoric acid is poor in quality and low in concentration. It can only produce fertilizer without purification, and the conversion rate of phosphorus can only reach 90%. Therefore, the application field of wet-process phosphoric acid is mainly concentrated in the fertilizer industry

There are still many defects in this process method, such as: the start-up of the system requires high-temperature phosphorus hot metal, and the system can only be produced intermittently and cannot realize continuous operation; multiple reactions are completed in the same reactor, which is difficult to operate and control; high-speed phosphorus Mineral powder, coal powder and phosphorus pentoxide gas are in countercurrent contact, which makes the phosphorus pentoxide gas carry dust, which seriously affects product quality; the waste residue has high phosphorus content and is difficult to use. This technology is difficult to realize industrialization

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