Study On Removal Of Nitrogen Compounds From Salt Slag In Hydrazine Hydrate Production

As a kind of fine chemical industry raw materials, hydrazine hydrate is of wideusage. The way of production of hydrazine hydrate in domestic and abroad industrialso far mainly include: ketone of urea and ammonia method, the main way in China isurea because of the technology and the enterprise survival.There will be a largeamounts of salt slag in the procession of prioducting hydrazine hydrate by the way ofuaea. The main ingredients of salt slag is sodium chloride, sodium carbonate andsodium hydroxide,besides it can’t be used directly because it contains a small amountof urea, nitrogen compounds, such as hydrazine hydrate. Optionally can cause seriousimpact on the environment,at the same time violate the state laws, so most of themanufacturers can only accumulate them which cause serious wasting of resourcesand environmental hazards.As to the usage of salt slag,the main processing method indomestic include separation method in high temperature and pyrolysis method, salineto remove oxidation and so on, after processing the salt slag can be used in theproduction of caustic soda, soda ash, sodium fluoride and other related products.In combination with the present situation of some chemical enterprise productionin jiangxi,the topic mainly plans to use the salt slag to ionic membrane system,combined with theoretical analysis and the laboratory test, I determined the feasibleway as oxidation and comprehensive. The optimum operation condition is the thermaldecomposition temperature as450℃, the time will be40min and the solid-liquidratio as1:2in the configuration brine solution, the ratio of36%hydrochloric acidand the saline solution is3:25, the ratio of sodium hypochlorite (including chloride10%) and solution is1:25, the temperature can be controled at50℃.The test results show that the total nitrogen concentration in the dealed salinesolution is3.7mg/L under the optimum operation conditions,and the total nitrogen inthe salt slag is about11PPM after the conversio, the removal rate of nitrogencompounds is99.79%, close to the caustic soda production requirements in the totalnitrogen concentration of salt10PPM. Saltine solution can be used to brine refiningprocession to product causti after simple alkalinity adjustment by comprehensive treatment,hydrazine hydrate can be used fully by this way,improving the economicbenefits and environmental benefits in the way of urea andit is benefit for thedevelopment of enterprises which product hydrazine hydrate.