The Research For Controlling The Releasing Speed Of Chlorine Dioxide

Chlorine dioxide is a potent disinfectant,only the oxidation reactionduring,no chloropHthalic reaction happens during the disinfection,it does not produce carcinogenic substances such as chlorinated hydrocarbons,its oxidative capacity is 2.6 times as chlorine. So it is attented by people amore and more, the United Nations, WHO has designated as it's A level security disinfectants.Develope a new urea salt-urea nitrate,study the impact of its synthesis of the main factors and the basic properties of urea nitrate; use a new type of carrier -Maifan stone,study its basic nature, and its modified research;study on the feasibility of slow release of chlorime dioxide implemented at room temperature with the main reaction of solide sodium chlorite and urea nitrate,Produce a solid sustained-release chlorine dioxide disinfectant,Determination of the release of chlorine dioxide.At the preparation of urea nitrate,the molar ratio of nitric acid and urea,nitric acid concentration,reaction temperature,reaction time are the major factors.After the experimental study we find that the optimum conditions are:molar ratio of urea and nitric acid is 1:1, the molar concentration of nitric acid is 5.5mol/L,reaction temperature is 20℃,reaction time is 20min.The analysis result to urea nitrate is:the stack density is 0.493g/cm³;the crystal shape is the prism shape;the solution acidity is weaker than the nitric acid, but Stronger than citric acid;the water absorbability is quite weak;The X-ray diffraction (XRD),nuclear magnetic resonance (NMR),infra-red spectrogram (IR) show that urea nitrate is a new coordination compound, can meet the request of H⁺ supply in solid slow-released chlorine dioxide,so it can instead some strong inorganic acid (such as nitric acid) and solid organic acid in some occasion as solid acid and has bright market prospect.The results show that it can be as theory base and reference for industrialized production, acidified reagent's modification in controlled release chlorine dioxide.The determination result to Maifan stone is that the main chemical composition of Maifan stone are SiO₂,Al₂O₃,K₂O and so on;rich in pHospHoric,potassium,magne- sium, calcium,boron,manganese and so on;XRD,IR show that the essential mineral of Nanyang Maifan stone are potash feldspar and SiO₂,it belongs to the shape silicate mineral;the Compared to surface area is 2.33m²/g,the hole volume is 5.637×10^-3cm³/g,the average hole radius is 48.35(?).The modified experiment to Maifan stone shows that:100℃activates 90 min to the Maifan stone is the best modified technological condition.The findings indicate that Maifan stone conforms to the carrier requestthe for preparation of solid slow release chlorine dioxide.Modified Maifan stone as the carrier,sodium chlorite and urea nitrate as the main component,to produce solid chlorine dioxide at normal temperature, which can release chlorine dioxide slowly rely on environmental humidity.The research to control the release rate of solid chlorine dioxide shows that,urea nitrate is practicable for Acidifier;the best mass ratio of Sodium chlorite and urea nitrate is 1:0.8,the ability of Maifan stone to control the release rate of ClO₂ is obvious,the mass of Maifan stone has a great impact to the release of ClO₂,solid chlorine dioxide produced can completely eliminate the security risks,is not required for activation before use,can release chlorine dioxide slowly,is also able to directly be used for disinfection of disposable after putting it in water at the same time,Shows good market competitiveness.Release kinetics of chlorine dioxide are non-catalytic flow-solid phase reaction,and it is in line with the shrinking core model.The whole reaction is divided into two parts, prophase belongs Gas film diffusion-controlled,and the other belongs Chemical kinetics controlled, The proportion of carrier can change the location of two parts.