Study On Recycle And Application Of The Long-term Stored RDX

RDX, with the characteristic of high strength and brisance, has been widely used in ammunition and civil explosive materials. Since it is a kind of strategic material, a necessary amount of reserve is required. The current national reserved RDX are mostly the products of the period from 1960s to 1970s, including compound RDX and passivated RDX. Due to the restriction of the producing condition and technology, some performance properties of the national reserved RDX have fallen out of application requirements, becoming a kind of waste material. The major problem of the national reserved compound RDX are the shape and granularity of crystal as well as the mechanical impurities resulted from the corrosion of the package; the major problem of the national reserved passivated RDX are the falling off the superficial passivator, the poor free-flowing property, agglomerating, the mechanical impurities and so on. Therefore, it is of great importance to study the recycling and reapplication of the waste RDX reserved.Through the analysis of the present situation, this study focused on the recycling and reapplication of the waste RDX reserved. The innovations and achievements of the study are as follows:(1) It is the first time to propose the concept of "special quality RDX". RDX with low sensitivity, high crystal density and narrow distribution of crystal granularity is called "special quality RDX". It aims at satisfying the specific requirements of new weapons and has become a special field of this area.(2) Constricted by the technology level, it is impossible to get "special quality RDX" directly and it can only be produced by deep process. As a representative of "special quality RDX", "250μm～425μm spherical RDX" calls for not only the narrow distribution of crystal granularity but also the spheroid of the crystal shape. In this study, technology research was conducted using waste compound RDX as solute, concentrated nitric acid as solvent to prepare "250μm～425μm spherical RDX", and some preparing parameters such as the concentration of the solution, the amount of dilution agent, the dilution speed, the temperature of crystallization, the stirring speed, the insulation time and so on have been determined. The obtained products have 77.6% the "250μm～425μm spherical RDX", and the bulk density reached 1.26g/cm³, increased by 31.3 percent compared to the normal RDX with the same granularity level; The mechanical sensitivity reduced 20 percent compared to the normal RDX with the same granularity level.(3) The preparation of special RDX for nonel (explosive lead) using waste RDX to prepare was researched. The solution concentration, crystallization temperature, crystallization time, stirring speed, were thoroughly investigated. The special RDX for normal nonel and the lead with high detonation velocity have been successfully developed. The application of 2.2 billion meters lead in 11 factories indicates the stable performance and effectiveness of the special RDX for lead.(4) The research of using waste RDX as raw material to produce high polymer bonded explosive shaped charge for petroleum was conducted. Through the study of the RDX granularity, the best ratio was got when the waste RDX/D₅₀≤25μm=9:1, the granulation technology was optimized:RDX:water=1:2; granulation temperature 55～60℃; the stirring speed:120r/min; distillation temperature:65℃～75℃; distillation vacuum: 0.04MPa～0.05MPa. The bulk density of the polymer bonded explosive reached 0.90g/cm³, which was 12.5 percent higher compared to R85 explosive,5.9 percent higher compared to SH-931 explosive; the perforation depth of the bonded explosive increased 7 percent compared to R85 explosive and SH-931 explosive. Above 120t waste RDX are transformed annually (above 300t cumulatively).(5) Wide and high frequency wavelet seismic charge with strong penetration was successfully developed and metal powder was used in seismic charge as additive for the first time. Seismic reflection records of the newly developed explosive showed that shallow scanning frequency was increased by more than 10Hz compared to seismic source with high detonation velocity.(6) The research of industrial recycling of passivated RDX was conducted for the first time in the country. With the solubilization of surfactant, the waste passivated RDX can be recycled. As a result, the purity of the RDX-H reached more than 99.65 percent, which was satisfied the requirements of civil explosive materials. More than 400t waste passivated RDX are transformed annually on average (800t cumulatively).(7) Using RDX-H as the major components, available explosive for detonator was developed successfully. Optimized technological condition are as follows:water:RDX-H=2:1; stirring speed for granulation:150r/min; demulsification temperature:50℃; granulation temperature:55℃～60℃; stirring speed for distillation:130r/min; distillation temperature: 65℃～75℃; vacuum:0.04MPa-0.05MPa. This technology has been used in large-scale production to transform RDX-H for more than 200t per year, and more than 500t cumulatively.