| The phosphorus chemical holds a very great proportion of Yunnan's economy,and phosphorus is important basic material of the phosphoric chemicals as well as Yunnan's main export poroducts.In phosphorus chemical industry,Waste gas,waste water and residual substances are generated.Phosphorus sludge from residual substance is an injurant with element P4.If there is a proper method can be used,it's not only may enhance the returns-ratio of phosphorus,but also reduce the environment pollution.Using the phosphorus sluge with NaOH to get sodium hypophosphite is an effective utilization way.Sodium hypophosphite,which is a reducing agent and widely used in galvanization,machinery, food processing has the very high economical value.But approximately 20%phosphorus convert to PH3 in this method,the new air pollution appears again.This thesis aims to research the method which using the sodium hypochlorite absorpt to PH3 to product sodium hypophosphite,and absorpt the rest of PH3 by utilizing the modified activated carbon.The main research includes desiring the appropriate response flow installment,selecting the appropriate solution to wash gas,finding the optimal absorption condition from the quality of sodium hypochloriten and pH,enhancing the sodium hypophosphite rate, and selecting the appropriate modified activated carbon to absorpt PH3.Phosphorus sludge(twenty gram)was set in the reactor,and the experiment conditions were as follows:the ratio of water to phosphorus at 110:1,the ratio of alkali to phosphorus at 3.6:1,the temperature at 85℃.PH3 with the nitrogen as the carrier gas were inducted into the cushion bottle,washing-gas bottle and the absorption bottle in turn.The flow speed of carrier gas was under 20mL·min-1,and the dense phosphoric acid was put into the washing-gas bottle.In the absorption bottle there were different quality of sodium hypochlorite solution,and the quality of solution were 0.75%,1%,2%,3%,4%,5%,6% and 7%,the pH value was 9 or 13.Through the experiments,such the solution were attained:the condition of sodium hypochlorite solution which the quality was 0.75%and 7%,and the pH was 9 acts as the first and second levels of absorbtion liquid,and which the quality was 7%,the pH was 13 acts as the last levels of absorbtion liquid.The activated carbon which were used are LJ-40 and ZP-3,as the modified object,was dried 12h under the 100-110℃,immersed by the 0.1mol·L-1CuSO4 or 0.1mol·L-1Cu(AC)2 for 24h(per 20g activated carbon for 100mL impregnating solution),dried 12h under the 110℃again,and roasted under the 300℃in the muffle at last,the modified activated carbon was get in this way.Through the experiment,following conclusions were get:The appropriate activated carbon is ZP-3,the best impregnating solution is 0.1mol·L-1Cu(AC)2.
|
PDF Full Text Request