Method for producing ultra-pure yellow phosphorus

Abstract

Disclosed is a production method of ultra-pure yellow phosphorus, which uses the material of industrial yellow phosphorus, and the industrial yellow phosphorus is prepared to be the ultra-pure yellow phosphorus via extracting, zone melting, pressurizing or depressurizing micro-filtration sequentially. Extracting agent is at least one of di-(2-ethylhexyl) phosphoric acid, tributyl phosphate or calixarene, diluting agent is kerosene or paraffin oil or chloroform or carbon tetrachloride, and extraction technological parameter is that the volume ratio of organic phase and the industrial yellow phosphorus is 1:2-1:3. Apparatus for zone melting comprises a zone molten pool, a ring heater, an annular chiller and a driving device, wherein the ring heater and the annular chiller are assembled around the zone molten pool, and are arranged at intervals along the axial direction of the zone molten pool, the pressurizing or depressurizing micro-filtration utilizes a pressurizing or depressurizing filter with grade of 0.1 um-0.5 um. Utilizing the invention of the method to purify the industrial yellow phosphorus, the purity of yellow phosphorus products can reach 99.99%-99.9999%, and the yield coefficient can reach 73.2%-88.4%.

Description

Technical field [0001] The invention belongs to a production method of ultra-pure yellow phosphorus, and particularly relates to a method for producing ultra-pure yellow phosphorus using industrial yellow phosphorus as raw material. Background technique [0002] Industrial yellow phosphorus is made by using SiO from phosphate rock in an electric furnace. 2 It is obtained through high-temperature reduction reaction with coke. The purity is generally about 99.8% and contains the following impurities: [0003] Metal elements: Ca, Fe, Al, Mg, Sr, Mn, Na, K, Ti, V, Cr, Ni, Ga, Cd, Cu, Sb, Pb, Zn, Sn, U. [0004] Semi-metallic elements: Se, Si, C, B, As, Bi. [0005] Organic matter: phenol, anthracene, tar and polyatomic polycyclic aromatic hydrocarbons, about 30 kinds or more. The color of yellow phosphorus is related to organic impurities, especially perylene and anthracene. The following substances account for about 70% of the total organic impurities in yellow phosphorus: ...

AI Technical Summary

Problems solved by technology

As can be seen from the above steps, the mechanical impurities in industrial yellow phosphorus are removed by distillation (physical method), and the most important impurities arsenic and organic matter in industrial yellow phosphorus are removed by chemical methods. The existing shortcomings mainly include: (1) Use concentrated sulfuric acid to stir and react with industrial yellow phosphorus, then stir and react industrial yellow phosphorus with nitric acid and oxidation enhancer

The safety of the stirring reaction between concentrated sulfuric acid and industrial yellow phosphorus is extremely low. There have been reports at home and abroad that this method has caused explosions; when the treated yellow phosphorus is mixed with nitric acid and oxidation enhancer, many data have proved that the effect of removing arsenic is limited. (See "Preliminary Study on the Production Process of High-purity Yellow Phosphorus", Yang Luhua, Ma Xinliang, Inorganic Salt Industry, Volume 36, No. 2, 2004; "Experimental Research on Removing Arsenic from Yellow Phosphorus by Aqueous Phase Oxidation", Ren Yongsheng, Zhang Zhen, Inorganic Salt Industry 2007, volume 39, No. 5), the inventor of this patent application has carried out multiple tests, and the test results also show that the effect of removing arsenic on yellow phosphorus is relatively poor, and the removal rate is low, only 90%. arsenic rate, phosphorus loss is very large

(2) Nitric acid and sulfuric acid are strongly acidic and highly corrosive substances. Due to the large amount of this method, it is inconvenient to recycle. If they are directly neutralized and discharged, they will cause environmental pollution and increase the cost of purification.

This method and equipment mainly have the following problems: 1. Part of the heat generated by the heater is used to heat the water in the water tank and does not contribute all the heat to the melting system, resulting in waste of energy; 2. With the increase of operating time, the water temperature Gradually increase, the cooling effect decreases; 3, the recovery method of finished yellow phosphorus increases equipment investment; 4, it is difficult to realize industrialized production

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