Comprehensive Utilization Of Phosphorus. Mud To Basic Research

Phosphorus is the important basic material of the phosphoric chemicals as well as Yunnan province's main foreign exchange gained product. Waste gas, waste water and residual substances are generated from phosphorus produce. Phosphorus sludge is an injurant containing element P4 formed in the process of phosphorus produce. How to make use of or deal with this injurant can not only increase the yield of phosphorus and reduce the production cost but also use the waste synthetically, thus eliminate the pollution on the environment. This thesis is mainly about the research of economically cleanly and efficiently dealing with phosphorus sludge, and the research is getting sodium hypophosphite from the phosphorus sludge.In this research we see about the influence of temperature on the experiments results as well as the ratio of water to phosphorus and the ratio of alkali to phosphorus. At last based on the results above, we select the optional amount of reaction chemicals and reaction conditions. Emulsification reagent is selected to ameliorate the conditions of the reactions. Mechanism of the reactions, kinetics and thermodynamics were studied in this study.Experiments of the effects that temperature, the ratio of water to phosphorus, the ratio of alkali to phosphorus and the ratio of NaOH to Ca(OH)2 are on the results are carried on, under the condition that adding CTAB in the reaction. The temperature influence experiments results showed that controlling temperature at the range of 80~90℃ is good for the procedure. The influence of the ratio of alkali to phosphorus experiments indicated that the ratio of alkali to phosphorus can not weigh alone whereas the useful factor is alkali to water, and the ratio is at 28.0-30.0. Experiments about the ratio of water to phosphorus effect showed range 105:1-115:1 is suitable. Optional NaOH to Ca(OH)2 5:1 was also concluded in the study. The optional reaction condition: temperature 85℃ , the ratio of water to phosphorus at 110:1 , water to alkali 29:1 and the ratio of NaOH toCa(0H)2 5:1 is concluded. Experiment done under the optional condition and as the result that the procedure cost 5.6h, the yield of sodium hypophosphite is 62.76%, the ration of the phosphorus converted into sodium hypophosphite is 78.62%,. And the content of sodium hypophosphite in the product is 98.79%, the content of sodium phosphite is 1.17% and the content of Calcium is 0.03 % . The result fits the specifications of the grade one in the industrial standard, and is very close to the specifications of the excellent.Under the condition that the ratio of water to phosphorus at 110:1, water to alkali at 29:1 and the ratio of NaOH to Ca ( OH) 2 5:1, and also adding CTAB we carried on the dynamic experiments at 70°C , 80°C , 85 "C and 90 "C .The reaction is one stair reaction can be concluded and thek tequation is Ca = Cao^* . And the equation of the reaction constant is asfollows: & = 60.03exp(-38911/i?:r), r2=0.9722. It can be seen from the enthalpy change data that the enthalpy change data of sodium hypophosphite and phosphine or hydrogen reacted from phosphorus and sodium hydroxide are -542.88kJ ? mol*1 and -711.54 kJ ? mol"', both are exothermic reactions. So the temperature increase is not good for the reactions.