Study On The Evaluation Index Of O.3 Method And Its Influencing Factors About The Classification Of Oxide Packaging

Oxidized solid packaging is very important in the transportation and storage.In 2015,in the?world's new global classification and label system for hazardous chemicals?(Revised Edition sixth),a new test method(called O.3 method)for the classification of oxidized solid packaging which has been changed in four aspects compared with the original test method(called O.1 method).However,the reference index of the burning rate is not provided.In order to provide a reference index for evaluating the burning rate of O.3 under common particle size,obtaining the packaging category of other oxidizing solid and finish the inspection quickly,in this paper,use the O.3 method and O.1 method,according to the principle that same particle size has same packaging,measured a set of reference values of the evaluation index of O.3 method,which not only provide convenience when use O.3method but also is beneficial to the application in the domestic.Meanwhile,a number of factors affecting the reference value are also determined,that provide a theoretical basis for improving the accuracy of the evaluation index.(1)The measured index of evaluation of O.3 method is 1.0408g/s,0.4968g/s,0.1955g/s,whose corresponding packaging category is class I,class II,class III.The packaging category of the oxidized solid obtained by the numerical system is the same as that obtained by the O.1method,the packaging category of potassium permanganate,potassium nitrate and sodium nitrate are class II,class I,class III.That is,for any substance to be tested,the ratio of microcrystalline cellulose to 1:1 or 4:1,if the mixture combustion rate is greater than1.0408g/s,it belongs to class I packaging;If the mixture combustion rate is greater than0.4968g/s but not up to the standard of class I,which belongs to class II;If the combustion rate of the mixture is more than 0.1955g/s,the standard that can not reach the class II packaging which belongs to the class III;if the combustion rate of the mixture is less than0.1955g/s,it belongs to non-5.1 oxidation solid.(2)Cellulose particle size had influence on the evaluation index of O.3 method.With the increase of the particle size of cellulose,the burning rate of the evaluation index decreased,which resulting in the reduction of the limits of the packaging category.For the oxidized solids that are close to class I packaging but belong to class II packaging,cellulose particle size increased will make it into class I;For the oxidized solids that are close to class II packaging but belong to class III packaging,cellulose particle size increased will make it into class II,such as the Potassium Permanganate from class II to class I packaging,can not accurately reflect the material risk.(3)The addition of wind shield has a great influence on the evaluation index of O.3method.When there is no wind shield,the numerical value of each measurement is very large and the accuracy is low,the relative standard error is also very large,and the combustion rate of each packaging category has no change,according to these values to evaluate the result of the packing of the oxidized solid result in confusion.Some can not even get the exact category,which shows that the wind speed,the oxygen content of the mixture has a great influence on the experimental results.(4)The mixing time has influence on the evaluation index of O.3 method.With the increase of stirring time,the combustion rate of the mixture of calcium hydroxide gradually increase.After 120 s,the rate remained stable.Among them,120 s is the best stirring time,the extension of the mixing time makes the packing category of potassium nitrate from I to II,and the class of sodium nitrate is changed from III to-5.1,the change of packaging level shows the danger of weakening,which is more likely to lead to accidents.(5)Inert medium not only has an influence on the 0.3 methods,but also has an effect on the burning rate of the material,different concentrations and different kinds of inert medium lead to different combustion rate.For the evaluation index,when the ratio is 3:1,the maximum rate of change when the concentration of silica is 28.6%,when the ratio is 1:1,concentration of silica is 23%,when the ratio is 1:2,concentration of silica is 23%;For potassium permanganate mixture,the best inhibitory effect of silica concentration is 47.5%,two hydrogen ammonium phosphate inhibition is best when the mass concentration is 50%;For the mixture of potassium nitrate,the best concentration of silica is 37.5% of the total weight of the mixture.